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Q\LIFGRNIA
FISH-GAME

"CONSERVATIOK OF WILDLIFE THROUGH EDUCATION"

California Fish and Game is a journal devoted to the conservation of wild-
life. If its contents are reproduced elsev/here, the authors and the California
Department of Fish and Game would appreciate being acknowledged. ^

Subscriptions may be obtained at the rate of $5 per year by placing an
order with the California Department of Fish and Game, 1416 Ninth Street,
Sacramento, California 95814. Money orders and checks should be made out
to California Department of Fish and Game. Inquiries regarding paid sub-
scriptions should be directed to the Editor.

Complimentary subscriptions are granted, on a limited basis, to libraries,
scientific and educational institutions, conservation agencies, and on exchange.
Complimentary subscriptions must be renewed annually by returning the post-
card enclosed with each October issue.

Please direct correspondence to:

i.
Kenneth A. Hashagen, Jr., Editor
California Fish and Game
1416 Ninth St.
Sacramento, California 95814

VOLUME 64

OCTOBER 1978

NUMBER 4

Published Quarterly by

STATE OF CALIFORNIA

THE RESOURCES AGENCY

DEPARTMENT OF FISH AND GAME

LDA

STATE OF CALIFORNIA
EDMUND G. BROWN JR., Governor

THE RESOURCES AGENCY
HUEY D. JOHNSON, Secretary for Resources

FISH AND GAME COMMISSION

BERGER C. BENSON, President

San Mateo

SHERMAN CHICKERING, Vice President ABEL GALLETTI, Member

San Francisco Rancho Palos Verdes

RAYMOND DASMANN, Member ELIZABETH L. VENRICK, Member

Santa Cruz Cardiff-by-the-Sea

DEPARTMENT OF FISH AND GAME
E. C. FULLERTON, Director

1416 9th Street
Sacramento 95814

CALIFORNIA FISH AND GAME
Editorial Staff

KENNETH A. HASHAGEN, JR., Editor-in-Chief Sacramento

DARLENE A. OSBORNE, Editor for Inland Fisheries Sacramento

RONALD M. JUREK, Editor for Wildlife Sacramento

J. R. RAYMOND ALLY, Editor for Manne Resources Long Beach

DAVID A. HOOPAUGH, Editor for Salmon and Steelhead Sacramento

DONALD E. STEVENS, Editor for Striped Bass, Sturgeon, and Shad Stockton

CONTENTS

233

Page

Northern California Dungeness Crab, Cancer magister, Move-
ments as Shown by Tagging Daniel W. Cotshall 234

Food Selection by Five Sympatric California Blackbird

Species Frederick T. Crase and Richard W. Dehaven 255

The Infauna of a Subtidal, Sand-Bottom Community at Impe-
rial Beach, California Deborah M. Dexter 268

California Ocean Shrimp Mesh Experiment Nancy C. H. Lo 280

Notes

Migration of American Coots Wintering in Northwestern Cali-
fornia Charles F. Yocom, R. J. Bogiatto, and J. C. Eshelman 302

A Diver-Operated Net for Catching Large Numbers of Juvenile

Marine Fishes Kim McCleneghan and James L. Houk 305

Sighting of a California Sea Lion, Zaiophus californianus
californianus, in the Sacramento-San Joaquin
Estuary Richard M. Sitts, Stephen P. Hayes, and Allen W. Knight 307

Book Reviews 309

Index to Volume 64 313

234

Calif. Fish and Came (A{A): 234-254 1978

NORTHERN CALIFORNIA DUNGENESS CRAB,

Cancer magister,
MOVEMENTS AS SHOWN BY TAGGING ^

DANIEL W. GOTSHALL

Operations Research Branch

California Department of Fish and Game

From 1956 through 1967, 6,209 male Dungeness crabs were tagged and released off
northern California from Usal to Pelican Bay. A total of 1,434 tags was returned, 1,073
with catch data. Two hundred four (19%) of the returnees with catch data came
from within 1.8 km (1 mile) of the release area. The populations of juvenile and adult
Dungeness crabs appear to be discrete in the areas between Fort Bragg and Cape
Mendocino and False Cape to Pelican Bay. Generalized movement models are
proposed for crabs tagged between Fort Bragg and Cape Mendocino; False Cape and
the Klamath River; Klamath River and Brookings, Oregon.

INTRODUCTION

Intermittent tagging studies of Dungeness crabs have been conducted off
northern California since 1956. Two of the studies off the northern coast were
reported by Jow (1960, 1965). These tagging studies were conducted to deter-
mine movements and rates of survival, growth, and exploitation.

The tagging studies reported here were conducted in 1956, 1958, 1962, and
1964-67 on male crabs from Usal north to the Oregon border (Figure 1 ). The
results (including data from Jow's tagging operations) are presented in terms of
movement behavior and stock definition.

METHODS

Three kinds of tags were used: plastic Peterson discs, stainless steel straps, and
suture tags. Peterson disc tags were used in 1956, 1962, and to some extent
during 1964 and 1965. In addition, during the 1956 study, several hundred crabs
were tagged with stainless steel strap tags. These tags consisted of a piece of
stainless steel plate 0.02 x 1.3 x 5.1 cm (0.008 x 0.5 x 2.0 inches) attached to
the lateral spines by stainless steel wire loops. Some crabs were tagged with both
Peterson discs as well as the strap tags to compare shedding rates. It was hoped
that fishermen would notice the strap tag more readily than the Peterson discs.
Suture tags were used in 1958, 1964, 1965, 1966, and 1967 studies (Butler 1957;
Snow and Wagner 1965). Crabs were captured with standard commercial type
traps or otter trawls fished from Department of Fish and Game research vessels.
Records were kept of size and shell condition of each crab tagged.

Recovery data were divided into two categories: crabs that remained within
a 1.6-km (1-mile) radius of release site, and crabs that moved from the release
area. Crabs which moved from the release area were grouped by 30-day inter-
vals of days at liberty. The movements for each 30-day interval were collated
into kilometers of movement north or south and inshore or offshore movement
from the release site.

' Accepted for publication October 1977.

DUNCENESS CRAB MOVEMENTS

235

.Shelter Cove

Tagging Stations
and Periods
• 1958-59

Bear Landing

3940

Weslport

915m 18 3.T

.124°

183m ^Trinidad R.

Stations

and Per

ods

1956

-57

May

958

Nov

958

•

1964

■

1965

1966

1967

40°40'

124 20

Tagging Stat

ons

and Pb

lods

1956

•

Nov

956

Mir 19S8

■

1962

1965

Big Lagoon

aging Stations

and Pe

■Ods

1956-

Apnl

May

958

1963

1966

FIGURE 1. Tagged Dungeness crab release sites. Upper left: Usal to Shelter Cove, 1958; Upper
right: Eel River to Trinidad, 1956 to 1967; Lower left: Rocky Point to Klamath River,
1956 to 1965; Lower right: Crescent City to Brookings, Oregon, 1956 to 1966.

236

CALIFORNIA FISH AND GAME

RESULTS

1956

A total of 705 legal sized male crabs (159 mm [6.25 inches] carapace width
or larger) was released in the area between False Cape and the California-
Oregon border in autumn (Table 1 ). Peterson discs were used on 237 crabs,
strap tags on 235 crabs, and 239 crabs were tagged with both types. Of the 227
tagged crabs recovered, 65 were Peterson disc tagged, 69 had strap tags, and
67 carried both tags. In addition, 18 crabs were captured that had been double
tagged originally but on which only the Peterson disc remained; and 8 were
recovered with only the strap tag intact. Both tag types were subject to loss;
however, fishermen did report taking off one of the tags and re-releasing some
of the crabs.

TABLE 1. Number of Tagged Dungeness Crabs Released and Recovered off Northern

California, 1956-1967. *

Tagging
dates

Nov, 1956

Apr. to Dec. 1958

Nov. to Dec. 1962

Oct. 1964 to June 1965.
July 1965 to Feb. 1966 .
Nov. 1966 to June 1967
July to Nov. 1967

TOTAL 6,209

Release

Recoveries

depth

Crabs

with catch

Recovered in

Number

range

(m)

reco

No.

vered

data

release

No.

area

released

No.

705

22-55

Ill

ll.l

201

88.5

35.8

2,079"

18-66

401

19.3

151

37.6

7.9

901

18-33

531

58.9

471

88.7

169

35.8

1,022

2-55

144

14.1

137

95.1

4.4

348

11-58

8.3

82.8

0.0

1,109

4-46

100

9.0

87.0

4.5

4-66

1,434

23.0

1,073

74.8

204

19.0

* Includes data from Jow's studies (1960 and 1965).
•• 453 released in April and May.

Catch data are available for 201 of the recoveries. Twelve (6%) of the
recovered crabs were captured within the release area.

Sixty-nine (76%) of the crabs originally released in the area between the Eel
River and Mad River were recovered north of their release sites (Figures 1 and
2 ) . Two crabs had not moved either north or south, and the remaining 20 moved
south. The average northerly movement was 54 ktn (32.4 miles), the average
southerly movement, 14.8 (9.2 miles). No southerly movement was recorded
after 150 days at liberty. Sixty-seven (74%) of the recoveries were closer to
shore than their release point. The change in depth for crabs moving inshore
ranged from 2 to 48 m (1 to 26 fm). For crabs moving offshore the change in
depth ranged between 2 and 16 m (1 and 9 fm).

Sixty-one crabs originally released between Rocky Point and the Klamath
River were recovered: 54 (88%) of them during the 1956-57 season and the
remainder during the 1957-58 season. Only 9 (8%) of the crabs were recovered
south of their release site (Figures 1 and 3). The average southerly movement
was 17.7 km ( 1 1 miles). The average northerly movement was 41 km (25.5
miles) for crabs recovered during the 1956-57 season. Forty-five of the crabs
recovered during the 1956-57 season moved inshore; the range in depth change

DUNCENESS CRAB MOVEMENTS 237

was 6 to 38 m (4 to 21 fm) . Northerly movements for six crabs recovered during
the 1 957-58 season averaged 41 .5 km ( 25.8 miles ) . One crab moved 26 km (16
miles) south. Five of the recovered crabs had usable catch data and had moved
inshore; the range in depth change was 1 6 to 35 m ( 9 to 1 9 fm ) . Depth recovery
could not be determined for seven returns in the 1956-57 season and three
returns in the 1957-58 season.

Recovery data from crabs released between Crescent City and Brookings,
Oregon (Pelican Bay) yielded contrasting results (Figures 1 and 4). Only seven
of 45 recoveries (16%) during the 1956-57 fishing season were from north of
the release site. The average northerly movement was 0.1 km (0.4 miles). The
average southerly movement was 30.6 km (19 miles) for 38 recoveries. Only
one crab was recovered during the 1957-58 season, 64 km (40 miles) north of
the release area. All but one of the crabs were recovered inshore of the original
release depth. The change in depth for inshore movements ranged from 2 to 22
m (1 to 12 fm).

1958

During 1958, 2,079 crabs were tagged and released between Fort Bragg and
Crescent City (Table 1, Figure 1 ); 453 (326 sublegal and 127 legal sized) were
tagged and released during April and May, the remaining 1,626 during Novem-
ber and December. The latter were all legal sized. Of 401 recoveries, 151 (38%)
were returned with catch data, and 32 (8%) of these were recovered within 1.6
km (1 mile) of the release site.

Of the 897 crabs released in the Usal to Shelter Cove area in November and
December, slightly more than one half (31 ) of the total recoveries (54) came
from south of their release sites. Most recoveries occurred during the 1958-59
season. Twenty-four crabs moved an average of 12.9 km (8 miles) south and
23 crabs moved an average of 10.5 km (6.5 miles) north (Figure 5). Five crabs
moved either inshore or offshore with no corresponding north or south move-
ment. Two crabs were recovered during the 1959-60 season, one had moved
11 km (7 miles) north, the other, 6 km (4 miles) south. Eight crabs were
recovered inshore of the release site and 38 offshore. The change in depth for
inshore recoveries ranged from 1 .8 to 7.3 m (1 to 4 fm ) ; offshore depths ranged
from 2 to 24 m (1 to 13 fm). None of the 64 crabs released in this area during
May was recovered.

Four hundred ninety-three tagged crabs were released between Table Bluff
and Trinidad; 193 during April and May, the remaining 300 during November
and December. None of the crabs released between Table Bluff and Trinidad
during April and May was recovered during the 1957-58 fishing season. Six were
recovered during the 1958-59 season; four of these moved an average of 60.4
km (37.5 miles) north. Two crabs moved an average of 18.5 km (11.5 miles)
south. Four crabs were recovered inshore from the release depths. The change
in depth ranged from 6 to 13 m (3 to 7 fm). Thirty crabs released during
November and December were recovered with catch information; all recoveries
were made during the 1958-59 fishing season. One crab moved inshore but the
north/south movement could not be determined from the catch data, and one
crab moved inshore with no corresponding north or south movement. Nineteen
(63%) came from north of the release sites. Eight were recovered south of the
release sites. The average northern movement was 41.2 km (25.6 miles); the
average southerly movement was 9.2 km (5.6 miles). Eighteen (70%) of the

238

CALIFORNIA FISH AND CAME

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DUNCENESS CRAB MOVEMENTS

239

T3 *-

o
o

(43.0)

(51.5)

jan kilometers moved 0

Klamath
River

(148.1)

(45.9) (19.3) ;59.5)

31-60 61-90 91-120 121-150 151-180 181-210 2n-240'241-270

Days at Liberty

32 2)

Numbers Recovered
Offshore Inshore

' ^**-f-f**^f**M

<*S*«

(25.7J

1124 20

41*

Big
Lagoon

FIGURE 3. Recovery data for tagged Dungeness crabs released between the Big Lagoon and
Klamath River, 1956.

240

CALIFORNIA FISH AND GAME

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DUNCENESS CRAB MOVEMENTS

241

>
o
o
a>
cc

Shelter Cove

(103)

0-30 31-60 61-90 91-120

Days at Liberty

Mean kilometers moved

(11.3)

361-390

451-4801

6.4)

(18.0)

o
o

Numbers Recovered
Offshore Inshore

•♦-•
k_
(\)

«>

1
5

•

:^:ii

o
■o

1
o

■1%%-v

124 20

FIGURE 5. Recovery data for tagged Dungeness crabs released between Usal and Shelter Cove,
1958.

242 CALIFORNIA FISH AND GAME

crabs moved inshore from the release depths; six of the recoveries lacked depth
of recovery data. Inshore movement ranged from 2 to 35 m (1 to 19 fm).

Nine of 1 19 crabs tagged and released between Big Lagoon and Crescent City
during April and May were recovered during the 1957-58 fishing season. Eight
moved north an average of 7.4 km (4.6 miles) and one moved south 9.6 km (6
miles). One crab was recovered during the 1958-59 fishing season 40 km (25
miles) south of the release site. All of the crabs with depth of recovery data
moved inshore from 11 to 48 m (6 to 26 fm).

Thirty-nine recoveries from 376 tagged crabs released in the area between
Patrick's Point and the Klamath River mouth during November and December
showed a different pattern than did the 1956-57 recoveries from this area
(Figure 6). Twenty (50%) compared to nine (8%) during the 1956-57 study
were recovered south of the release sites. The average southerly movement was
21 km (16.8 miles). The 18 crabs that moved north averaged 27.2 km (16.9
miles). Inshore-offshore movements, however, did show similar results for the
two recovery periods. Most crabs were recovered inshore. Recovery depths
could not be determined for five crabs. Offshore depth changes ranged from 2
to 7 m (1 to 4 fm); inshore depth changes from 2 to 43 m (1 to 24 fm). None
of the 141 crabs released between the Klamath River and Pelican Bay during
April and May was recovered.

1962

A total of 901 legal sized crabs was released during November and December
1 962, 825 in Pelican Bay and 76 off the Klamath River ( Figure 1 ) . Three hundred
twenty-two crabs (36%) were recovered within 1.6 km (1 mile) of the release
site. Data from 282 recovered crabs released in Pelican Bay and 30 released off
the Klamath River were sufficient to study movement.

Twenty-eight (10%) Pelican Bay tagged crabs were recovered during the
1962-63 fishing season and had moved inshore or offshore with no correspond-
ing north or south movement. One hundred eighteen (42%) were recovered
an average distance of 6.9 km (4.3 miles) north of the release sites, and 127
(45%) an average distance of 11.7 km (7.3 miles) south of the release sites
(Figure 7). One crab that moved 10 km (6 miles) south was recovered during
the 1963-64 fishing season. One hundred sixty-seven crabs (86%) moved in-
shore from the release depths; these movements ranged from 2 to 25 m (1 to
14 fm). Eighty-eight crabs were recovered with incomplete depth of recovery
data.

The crabs released off the Klamath River showed a stronger tendency to move
south; 19 (63%) were recovered south of their release sites an average distance
of 13.2 km (8.2 miles). Nine crabs moved north an average distance of 8.7 km
(5.4 miles). Two moved inshore of the release site with no corresponding north
or south movement. The two offshore movements were limited to the first 30
days at liberty. Twenty-three crabs moved inshore from 3 to 21 m (2 to 12 fm).

1964-65

From October 1964 through June 1965, we released 383 sublegal and 64 legal
sized crabs inside FHumboldt Bay. Ten were recovered, four inside the Bay and
six outside (Table 2). Eighty-four (17%) of the 487 sublegals and 52 (60%) of
the 88 legal sized crabs released outside the Bay were recovered, none inside
the Bay. No sublegal sized crabs recovered during the 1964-65 season had

DUNCENESS CRAB MOVEMENTS

243

■ors

0) o
o

«>
E

Mean kilometers moved ( )

(28.2)

0-30

(38.6)

31-60

61-90 91-120

121-151

151-180

Days at Liberty

^WWWVVS:

12.9)

(35.6)

Numbers Recovered
Offshore Inshore

ej}.'**.*.*.*.

tl >^

rt<fit^^**^%

Klamath
ver

4120

124 20

Patrick's Pt.

FIGURE 6. Recovery data for tagged Dungeness crabs released between Patrick's Point and the
Klamath River, 1958.

2—77851

244

CALIFORNIA FISH AND GAME

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DUNCENESS CRAB MOVEMENTS

245

246 CALIFORNIA FISH AND CAME

molted; most were released again by the fishermen. All crabs recovered during
the 1965-66 season, however, had molted.

Two sublegal crabs released inside the Bay during November and December
were recovered outside the Bay. One was recovered after 46 days at liberty 1 1
km (7 miles) north of the entrance to Humboldt Bay; and one was recovered
after 473 days at liberty (during the 1965-66 fishing season) 8 km (5 miles) south
of the entrance to Humboldt Bay. Only one of the legal sized males released
during this period was recovered; after 32 days at liberty this crab had moved
about 1.6 km (1 mile) southwest of the entrance to Humboldt Bay.

Eighteen (6%) of the sublegal sized crabs released outside of Humboldt Bay
during November and December were recovered during the 1964-65 fishing
season. Eleven (61%) of these moved north an average distance of 58.7 km
(36.5 miles) (Figure 8). The average southerly movement for seven crabs was
15 km (9.3 miles). Eight crabs moved offshore from 4 to 39 m (2 to 21 fm);
however, there were no offshore recoveries after 150 days of liberty. Nineteen
crabs were recovered inshore of their release depths. The depth change ranged
from 2 to 32 m (1 to 1 8 fm ) . One legal sized crab released outside the Bay during
this period was recovered 6 km (4 miles) north of the release site after 180 days
at liberty.

Five sublegal crabs were recovered during the 1965-66 fishing season; three
north of the release site, one south, and one offshore with no corresponding
north or south movement. One crab moved offshore and one inshore, and three
were returned with insufficient depth of recovery data.

During January, February, and March, we tagged and released 182 sublegal
and 33 legal sized males inside Humboldt Bay. Four (12%) of the legal sized
crabs were recovered during the 1964-65 fishing season, all had moved outside
the bay. Three moved south of the bay entrance an average of 12.9 km (8 miles),
while one moved 3 km (2 miles) north. One of the sublegals was recovered
outside the Bay during the 1964-65 season, 3 km (2 miles) north of the Bay
entrance.

A total of 189 sublegal and 84 legal sized males was tagged and released
outside of the bay during the same period. Commercial fishermen recovered 38
(20%) of the sublegalb and 48 (57%) of the legals during the 1964-65 season
(Figure 9). Forty-three (90%) of these legal sized crabs and 25 (66%) of the
sublegals were recovered south of the release sites. Most of the 20 crabs recov-
ered north of the release sites were from the March releases. The average
southerly movement was 11.1 km (6.9 miles), the average northerly movement
was 7.6 km (4.7 miles). Seven crabs moved offshore from 4 to 9 m (2 to 5 fm),
the remaining 79 were recovered inshore of the release depth. Inshore move-
ment ranged from 2 to 9 m (1 to 5 fm) (Figure 10).

1965

We continued the studies begun in 1964 by tagging an additional 348 crabs;
85 inside Humboldt Bay and 263 outside, all during November and December
(Table 2, Figure 1 ) . All but one were sublegal sized and, for the most part, those
recovered during the 1965-66 season were released by the fishermen. Only one
crab released inside the bay was recovered, having been captured 29 km (18
mik*^' liouth of the entrance to the bay after being at liberty 39 days.

Nine recoveries of crabs released outside the bay were made during the

DUNCENESS CRAB MOVEMENTS

247

FIGURE 8. Recovery data for tagged Dungeness crabs released between the Eel River and Mad

Rivpr IQfvd

248

CALIFORNIA FISH AND CAME

Jan.

(12,9)

(64)

0-30 31-60 61-90 91-120

Mean
kilometers
moved
()

■o
o

>
o
o

C9.3i ^7.7) C177)

0-30 31-60 '61 90 91-120
Days at Liberty

Humboldt

Eel River

Subl«gal
Legal

,124 20

FIGURE 9. North-south recovery data for tagged Dungeness crabs released between the Eel River
and Mad River, January to March, 1965.

DUNGENESS CRAB MOVEMENTS

249

Numbers Recovered
Offshore Inshore

Mar.

Feb.

Jan.

Humboldt Bay

Eel River

^- Sub legal
■I - Legal

,124 20

FIGURE 10. Inshore-offshore recovery data for tagged Dungeness crabs released between the Eel
River and Mad River, January to March, 1965.

250 CALIFORNIA FISH AND CAME

1965-66 season, five north and four south from the release site. Five crabs
moved inshore, and two offshore from the release depth. The average northerly
movement was 52.1 km (32.4 miles), the average southerly movement was 20. .3
km (12.6 miles). Inshore movements ranged from 15 to 38 m (8 to 21 fm). Two
tags were reported with incomplete depth of recovery data.

During the 1966-67 fishing season, 15 of these crabs released outside the Bay
were recovered, all had molted. Four crabs were recovered south of the release
site. They had moved an average of 18.5 km (11.5 miles). The 11 crabs recov-
ered north of the release site moved an average of 60.8 km (37.8 miles). Most
( 10) had moved inshore of the release site 4 to 31 m (2 to 17 fm). The depth
of recovery could not be determined for three crabs.

1966

To complete the movement studies, we released an additional 1,109 crabs
between July 1966 and June 1967 (Table 2). Most of the crabs were released
in water 6 to 15 m (3 to 8 fm), somewhat shallower than earlier studies which
were released in 14 to 55 m (8 to 30 fm). Inside Humboldt Bay, we captured
and tagged 310 sublegal and 75 legal sized crabs. Three of the sublegal sized
crabs were recaptured during the 1966-67 fishing season, all outside of the Bay.
Two of the crabs were recovered south of the Bay entrance and one north. None
of the legal sized crabs was recaptured.

We captured and tagged 717 sublegal and 7 legal sized crabs between FHum-
boldt Bay and Crescent City Harbor during November and December 1966.
These crabs were released at the entrance to Humboldt Bay, in Trinidad Harbor,
and in Crescent City Harbor. Of 229 crabs released off Humboldt Bay and in
Trinidad Harbor, commercial fishermen reported capturing 47 sublegal and 2
legal sized crabs during the 1966-67 season. The fishermen released most of the
undersized crabs. Thirty-one (64%) of the crabs were recovered north of their
release sites (Figure 11 ); however, after 120 days at liberty, slightly over 50%
(19) of the recoveries came from south of the release sites. The average north-
ward movement was 23.5 km (14.6 miles). The average southerly movement
was 13.2 km (8.2 miles). The majority had moved offshore, 3 to 36 m (2 to 20
fm), in direct contrast to previous experiments. All recoveries from shallower
than release depths occurred after 90 days at liberty.

A total of 20 crabs was recovered during the 1967-68 season, 15 (75%) of
the recoveries wep from north of the release site, an average of 52.3 km (32.5
miles) (Figure 14). Fhe average southerly movement was 19.6 km (12.2 miles).
Of the crabs originally released in shallow water ( 4 to 8 fm ) , all but one moved
to deeper water. The offshore change in depth ranged from 2 to 36 m (1 to 19.5
fm).

All of the recoveries from the 240 crabs (4 legals, 236 sublegals) released in
Crescent City Harbor were made during the 196&-67 fishing season. Only 12
(5%) of these crabs were recovered. Eight crabs moved south an average of
23.8 km (14.8 miles) and three crabs moved an average of 26.2 km ( 16.3 miles)
north of the harbor. One crab was recovered in the harbor. All recoveries with
depth of capture data were from deeper water than the release depth, ranging
from 3 to 43 m (2 to 24 fm).

1967

A few sublegal sized crabs were tagged and released in Humboldt Bay during

DUNGENESS CRAB MOVEMENTS

251

FIGURE n. Recovery data for tagged Dungeness crabs released between Humboldt Bay and
Trinidad, 1966.

1967 (Table 2): 220 from January through June and 29 from July through Octo-
ber. Three of these crabs were recovered outside of the Bay, one moved 6 km
(4 miles) north and two an average of 11.3 km (7 miles) south of the entrance
to the Bay. All were recovered deeper than the original release depth.

252 CALIFORNIA FISH AND CAME

One crab recovered 60 km (36 miles) north of the entrance came from a
group of 16 released at the entrance to the Bay in November.

DISCUSSION

Obviously, tag recovery locations depend upon where the fishermen fish their
traps. In northern California commercial fishermen begin the season fishing in
depths from 18 to 73 m (10 to 40 fm). During the 1969-70 season, some
fishermen were fishing as deep as 183 m (100 fm). As the catch-per-unit-of-
effort decreases in deeper waters, the traps are set in shallower water. By April
most traps are inside 18m ( 1 0 fm ) . During the past 1 0 to 15 years, traps have
been fished in most of the crab producing areas between Fort Bragg and the
California-Oregon border, particularly during the first 3 or 4 months of the
season. After the end of March, a large share of the fishermen leave the crab
fishery, hence, the area covered by the traps decreases significantly from April
until the end of the season in July. The results of all the studies have been
influenced by the aforementioned fishing patterns, thus the movement patterns
about to be discussed are influenced to a similar degree by the seasonal charac-
teristics of the commercial fishery.

Most of the crabs tagged during these studies were legal-sized males. Because
there does not appear to be a significant difference in the movement patterns
of the smaller males (based on the results of the 1964-65 study), recovery data
from legal as well as under-sized crabs are lumped together. Some of the studies
produced very small numbers of returns. Thus, most emphasis was placed on
those particular studies that yielded the highest return rates.

At first glance, the movements of crabs recorded during any one of the studies
do not present a definite pattern with the exception of the inshore-offshore shifts.
Jow (1960, 1965) felt that the returns from the crabs released in Pelican Bay in
1962, as well as data from the 1958 study, indicated intermingling of northern
California and southern Oregon populations. He also pointed out the inshore
movements trend.

I believe that examination of recovery data from all the studies suggests the
following:

1. Northern California male crabs, with the exception of crabs found in the
Usal-Shelter Cove area, tend to move offshore during the months of November
through March, then return to shallow water from March through June.

2. Crabs tagged in the area from Usal to Shelter Cove remained in that area,
making only short movements north or south. None of these tagged crabs was
recovered north of Cape Mendocino, and only two crabs were recovered south
of Fort Bragg.

3. Crabs from False Cape to Trinidad, and to a certain extent, to the Klamath
River, tend to move north from November through March. In all seven of the
studies conducted between the Eel River and the Klamath River, the majority of
tagged crabs released in November and December moved north, with one
exception; crabs released between Patrick's Point and the Klamath River in
November and December 1958, showed an equal tendency to move north or
south.

4. Crabs released between the Klamath River and Crescent City tended to
move south from November through March.

DUNCENESS CRAB MOVEMENTS 253

5. Pelican Bay crabs tended to move south during the first part of the fishing
season.

6. A substantial number of crabs from all of the studies remained in the same
area for long periods.

7. Crabs probably move with prevailing currents, particularly north and south
shifts. The north flowing Davidson current usually takes precedence off northern
California in November or December (Sverdrup, Johnson, and Fleming 1954).
The Davidson current disappears in late winter (February to April) with the
onset of prevailing northerly winds. Southerly movements observed during Da-
vidson current periods might be due to local eddy currents, particularly in
Pelican Bay and between the Klamath River and St. George Reef.

8. Benthic juvenile and adult crabs in the area between Fort Bragg and Cape
Mendocino are a discrete population with no immigration and very little emigra-
tion.

9. For all practical purposes, crabs from Cape Mendocino to Pelican Bay
should be considered one population, although there is more evidence of immi-
gration and emigration. Only 43 crabs released in this area were recovered north
of the Oregon-California border. None of the crabs released north of Cape
Mendocino has been recovered south of the Cape. Oregon biologists (Darrell
Demory, Oregon Fish Commission, pers. commun.) report that out of 1 13 crabs
tagged off Port Orford and returned with catch data, only one was recovered
south of Brookings.

10. There is little or no movement of adult crabs into Humboldt Bay, particu-
larly legal sized adults.

Cleaver (1949) found that tagged Dungeness crabs off Washington moved
north during late winter and had some evidence of return movement. FHe specu-
lated that the crabs moved to deeper water and moved south during the sum-
mer. Crabs living between Cape Mendocino and the Klamath River seem to
follow this pattern.

I propose the following models for northern California male crab migration:
From Cape Mendocino to the Klamath River, most males are in shallow water
in the late spring and early summer; as summer progresses, the crabs move
offshore and south with the prevailing currents. This movement continues at
least until December or January, then the crabs move toward shore and north-
ward with the Davidson current. The speculation regarding movements during
the summer and fall when the season is closed are based on crabs recovered
during their second season at liberty. From the Klamath River to Brookings,
Oregon, male crabs move to the north and offshore in late summer through early
winter; during late winter and spring, crabs move inshore and to the south.

ACKNOWLEDGMENTS

The following are thanked for their participation in the 1964-67 tagging stud-
ies: Nancy Nelson, Mel Willis, Steve Taylor, Bob FHardy, Pete Brown, and the
Captain and crew of the N.B. Scofield. Cathy Short produced the figures for all
of the studies. Tom Jow and Walt Dahlstrom provided many helpful comments
and background information on the 1956 to 1962 experiments. Their assistance
and contributions are gratefully acknowledged. Finally, I would like to thank all
of the commercial fishermen who cooperated in the experiments by returning
tags and catch data.

254 CALIFORNIA FISH AND CAME

REFERENCES

Butler, T. H. 1957. The tagging of the commercial crab in the (.Jueen Charlotte Island region. Fish. Res. BcJ. Can.,

Pac. Prog Rept., (109): 16-19.
Cleaver, F. C. 1949. Preliminary results of the coastal crab i Cancer magister) investigation. Wash. Stale Dept.

Fish., Biol. Rept., 49A:47-82.
)ow, Tom. 1960. Crab suture tag experiments. Calif Depart. Fish Came, MRO Ref. (60-1): 1-8.
. 1965. California-Oregon cooperative crab tagging study. Pac. Mar. Fish. Comm., 16th and 17ih Ann.

Reps.,: 51-52.
Snow, C. Dale, and Emery J. Wagner. 1965. Tagging of Dungeness crabs with spaghetti and dart tags. Oregon

Fish Comm., Res. Briefs, 1 1 ( 1 ) : 5-1 3.

Sverdrup, H. V., Martin W. Johnson, and Richard H. Fleming. 1954. The oceans. 2nd edition Prentice Hall, Inc.,
Englewood Cliffs, N.J. 1087 p.

255

Cdlif. Fish and Game 64 ( 4 ) : 255-267 1 978

FOOD SELECTION BY FIVE SYMPATRIC CALIFORNIA

BLACKBIRD SPECIES ^

FREDERICK T. CRASE ^ and RICHARD W. DEHAVEN

U.S. Fish and Wildlife Service

Denver Wildlife Research Center Field Station, Box C

Davis, California 95616

The percent volume of food items in stomachs and esophagi was tabulated for 875
adult and subadutt blackbirds of five species (tricolored blackbird, Agelaius tricolor;
red-winged blackbird, A. phoeniceus; yellow-headed blackbird, Xanthocephalus
xanthocephalus; brown-headed cowbird, Molothrus ater; and Brewer's blackbird,
Euphagus cyanocephalus) collected in the Sacramento Valley, California, 1967-72.
Seeds of cultivated grains, chiefly rice (Oryza sativa), made up 24% to 54% of the
annual diet of all species. Rice was eaten more than any other food by red-winged
(43.7%), yellow-headed (38.0%), and tricolored blackbirds (37.8%). Water grass
(Echinochloa spp) was the primary food of brown-headed cowbirds (45.9%), and
wild oats (Avenas[ip) the primary food of Brewer's blackbirds (17.6%). Insects were
eaten most in the spring and summer and made up 3 to 24% of the annual diet.

Statistical comparisons of percent volume for 11 major food classes (treating
stomach*^ and esophagi separately) revealed many significant (p<.05) differences
in food selection among species. Similar comparisons for six food classes also
showed some significant differences among tricolor and red-wing sex and age
classes. The differences among species and between sexes are likely related to
differences in bill size and structure, which affect the size of seeds that can be
handled efficiently and the ease of catching insects. The differences between adults
and subadults are likely related to difference in feeding experience. The use of rice
by red-wings and Brewer's has increased greatly since 1900 and 1931, mainly because
of changes in crop acreages and continued conversion of marshes and fields to
agricultural uses.

INTRODUCTION

Many agricultural damage problems by blackbirds involve several different
species that often feed together in mixed flocks. Biologists generally recognize
that not all blackbird species, or even all sex and age classes within a species,
contribute equally to damage, but no detailed analysis has been made of the
relative importance of these various groups for specific damage situations.

From 1964 through 1974, personnel of the U.S. Fish and Wildlife Service
studied blackbird damage to rice in the Sacramento Valley of California. The
problem is complex because five species (eight subspecies) of blackbirds are
present, as resident and migrant populations, during the fall damage season: the
tricolored blackbird, red-winged blackbird {A. p. californicus, A. p. caurinus,
and A. p. nevadensis) , yellow-headed blackbird, brown-headed cowbird
{M. a. artem/s/ae and M. a. obscurus) , and Brewer's blackbird.

Very little has been published on the foods of tricolored blackbirds, brown-
headed cowbirds, and yellow-headed blackbirds in California, and food habits
studies of red-winged and Brewer's blackbirds in California by Beal (1900),
Bryant (1912), Soriano (1931 ), and others were done before the era of intensive
rice culture. Studies were started in the fall of 1 967 to determine the food of each
blackbird species during the fall damage season and were later expanded to

' Accepted for publication )une 1978.

^ Current address: Bureau of Reclamation, Box 043, Boise, Idaho 83724.

256 CALIFORNIA FISH AND GAME

include all seasons. This paper summarizes the seasonal and annual foods of
adults and flying young of all five species and examines differences in food
selection among species and between tricolor and redwing sex and age classes.
Data we gathered on the food of nestling tricolors have been reported elsewhere
(Crase and DeHaven 1977).

STUDY AREA
Blackbirds were collected in Colusa, Glenn, and Butte counties, the major
rice-growing areas of the Sacramento Valley. This area is intensively farmed.
Rice is the primary crop, but grain sorghum (Sorghum vulgare) , safflower
iCarthamus tinctorius) , barley (Hordeum vulgare), wheat (Triticum
aestivum) , and fruit and nut crops are also grown. Four wildlife refuges provide
areas of natural marsh for nesting and roosting and also contain fields of rice and
water grass grown to reduce waterfowl damage on nearby non-refuge lands.
Several private gun clubs maintain areas of natural marsh. The Sacramento River,
numerous irrigation canels, drainage ditches, and sinks provide additional semi-
natural marsh habitat for blackbirds.

METHODS

About 80% of the 875 birds used for this study were shot at random from
evening flightlines into major communal roosts or in adjacent staging areas. The
remaining 20% were shot in loafing and breeding areas during spring when the
birds do not congregate into large roosts. Birds were taken on 74 different days
from September 1967 through )une 1972 (averaging 1 1 .8 birds/day) and during
all months of the year. Each sample was frozen as soon as possible, usually
within 2 hours of collection. For examination, each bird was thawed and dissect-
ed, and the contents of each esophagus and stomach (gizzard and proven-
triculus) were washed, assigned a number, air dried on blotter paper, and
examined under low magnification. Food items were identified and segregated
into piles, and the precentage of the total volume of each item was visually
estimated.

To examine food selection differences statistically, annual volume percent-
ages for major food groups were compared among species and between sex and
age classes for tricolors and red-wings. Comparisons were made by single-
classification analyses of variance on arcsin-transformed data, and the means
separated by Duncan's new multiple-range test; p <0.05 was accepted as signifi-
cant. For the among species comparison, each species was compared separately
with every other species (10 species pairs) for each food item; the esophagi and
stomachs were treated separately to remove digestion rates and percentage of
empty esophagi as variables in the comparison. Eleven food classes were com-
pared for stomach contents, and 10 for esophageal contents (esophageal grit
could not be meaningfully compared); thus, 21 tests for food selection differ-
ences were made for each species pair. For the comparisons between sex and
between age for tricolors and red-wings, the same tests were made for six food
classes except that esophageal and stomach data were combined.

RESULTS
Plant Foods
Rice was an important food for all five blackbird species, in terms of volume,
it ranked first in the annual diet of red-wings, yellow-heads, and tricolors, second

BLACKBIRD FOOD SELECTION 257

in the diet of cowbirds, and third in the diet of Brewer's (Table 1 ). Generally,
rice consumption was highest during the fall when maturing fields provided a
super-abundant food source, but large amounts also were eaten during the
winter when it was available as waste in harvested fields.

Water grass seed was the next most important blackbird food. It was eaten
more than any other item by brown-headed cowbirds and was second in impor-
tance for red-wings, tricolors, yellow-heads, and Brewer's. Although the volume
of water grass eaten was usually less than that of rice, the number of seeds taken
was greater because rice seeds are four to five times larger than water grass
seeds.

Seeds of cultivated grains (including rice) made up about one-half of the total
annual food volume of red-wings, yellow-heads, and tricolors, one-third of the
food of cowbirds, and less than one-fourth of the food of Brewer's blackbirds.
Of these grains, sorghum was second in volume after rice and was eaten in
similar percentages by all five species. Safflower, wheat, and cultivated oats
were also eaten, but in relatively small amounts. The esophagi contained higher
percentages of cultivated grains than did the stomachs. This may reflect some
differential digestion (see Discussion), but, because most of our collections
were from incoming flightlines to roosts, it may also be the result of the birds
"filling up" on readily available food just before roosting.

Wild oats, a common weed along roads and ditches and in fallow fields,
ranked first in the annual diet of Brewer's blackbirds. Oats were over 5% of the
diet of tricolors but were found in only small amounts, or were absent, in
red-wings, yellow-heads, and cowbirds.

Other wild seeds were eaten in small amounts by all species. Smartweed
( Polygonum spp ) , pigweed ( Amaranthus spp ) , filaree ( Erodium spp ) , and John-
son grass {Sorghum halepense) were the most common, but Bermuda grass (
Cynodon dactylon ) , switch grass ( Pan/cum spp) , catchfly { S/7ene spp) , bulrush
( Sc/rpus spp) , canary grass ( Phalaris spp) , and sprangletop { Lepthochloa spp)
were also eaten.

Animal Foods
Insects made up most of the animal food of all species. Beetles (Coleoptera)
were the main insect food of Brewer's, tricolors, and red-wings, whereas miscel-
laneous adult insects ranked highest for cowbirds and yellow-heads. Ground-
dwelling beetles (Carabidae, Tenebrionidae, and Chrysomelidae) and water
beetle larvae (Hydrophilidae) were the most important insect food of tricolors
and red-wings, and ground-dwelling beetles and weevils (Curculionidae) were
the insects eaten in the largest volumes by Brewer's. These beetle groups were
also the primary food of tricolor nestlings from the same general area (Crase and
DeHaven 1977) . Brewer's blackbirds ate a much larger volume of grasshoppers
and crickets (Orthoptera) than did the other four species. Generally, insects
were eaten most abundantly during the spring and early summer, the blackbird
breeding season. Hintz and Dyer (1970) have suggested that increased insect
consumption by adult red-wings during the breeding season was related to both
the increased availability of insects and the limited foraging time available to
obtain their required energy (due to the demands of breeding activity).

258

CALIFORNIA FISH AND GAME

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BLACKBIRD FOOD SELECTION

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BLACKBIRD FOOD SELECTION

261

Grit

Mineral grit was about 5% of the total food volume for all species except
Brewer's, for which it was about 12%. The figure for Brewer's is probably an
overestimate of actual intake because 89% of the esophagi for this species were
empty (see Discussion). Grit intake for all species was generally highest during
the spring and lowest during the fall. This contrasts with the findings of Bird and
Smith (1964) and Mott et al. (1972), who found that the least amount of mineral
grit was picked up when insects were a large portion of the diet.

Species Differences

In the examination of food selection differences among blackbird species, the
number of significant differences between species pairs ranged from 1 (5%) to
19 (90%) (Figure 1 ). Only one food class, grain sorghum, did not show at least
one significant difference among species (Table 2).

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FIGURE 1, Differential consumption of 1 1 food classes, testing esophageal and stomach contents
separately (21 tests), by five blackbird species in the Sacramento Valley, California;
TCBB = tricolored blackbird, RWBB = red-winged blackbird, BHCB = brown-head-
ed cowbird, YHBB = yellow-headed blackbird, BREW = Brewer's blackbird.

Considering some of the unavoidably small sample sizes for some of the
comparisons, it appears that the Brewer's and tricolor are most alike in their food
habits, and their food habits in turn differ most from that of the cowbird. The
tricolor and red-wing showed a large difference in food selection considering
their close phylogenetic relationship. The few statistical differences between
yellow-heads and the other four species are probably partly due to the small
sample size for this species. Likewise, the large number of empty Brewer's
esophagi may have affected the number of significant differences between this
and the other species. At any rate, each species apparently has its own pattern
of utilizing the available food supply.

262

CALIFORNIA FISH AND CAME

TABLE 2. Differences in Consumption of Major Food Items (percent of total annual vol-
ume in the esophagi and stomachs) Among Five California Blackbird Species.*

Food

Tricolored

Red- winged

Brown-headed

Yellow-headed

Brewer's

Item

blackbird

Esophagus

N =

(173)

(294)

(96)

(21)

(8)

Rice

43.0°

55.2''

30.5'

47.7"

22.8'

Grain sorghum ...

9.6°

8.8°

9.2°

14.4°

16.5°

Oats

5.0°

2.1"

0.3"

0.0

5.8°"

Water grass

12.4°

19.8'"

43.2'

34.7°"

5.4°"

Cultivated grains.

57.1°

66.5"

40.0'

62.1''

39.3°"'

Wild seeds

19.9°

24.8°

55.7"

36.7°

13.1°

Plant matter

77.0°

91.3"

95.7"

98.8"

52.4°

Ground-dwelling

beetles

3.0°

1.1"

0.4"

0.0

2.5°"

All beetles

13.6°

1.8"

0.5"

0.3"

6.9°"

All insects

19 6°

7.5"
Stomach

2.9"

0.5"

22.4°

N =

(267)

(384)
35.7'

(130)
22.0'

(21)
29.3"

(70)

Rice

34.0''

13.6'

Grain sorghum ...

6.3'

8.3"

6.4"

8.8'

6.1"

Oats

5.6'

1.6'

0.3'

0.0

17.8'

Water grass

20.8'

28.4'

47.7'

35.0'

17.9"

Cultivated grains.

43.0'

45.3'

28.5'

38.1"

22.5'

Wild seeds

31.3'

35.3"

57.7'

39.3"

41.6'

Plant matter

74.3'

80.6'

86.2'

77.4"y

64.1"

Ground-dwelling

beetles

6.2'

3.0'

1.1'

0.4'

11.2'

All beetles

11.9'

6.7"

1.5'

0.5'

13.5"

All insects

17.6'

9.4'
9.9"

3.0'
10.6'

14.5"'
8.0"

23.3"

Grit

8.1'

13.C

* Means compared using arcsin-iransformed data. Within each food item and organ, means followed by different
superscript letters are significantly different (p <0.05). Zero values cannot be compared by analysis of variance.

Sex Differences
For both tricolors and red-wings, six food classes were compared for differen-
tial selection by sex (Table 3 ) . Both tricolor and red-wing males ate significantly
more rice, cultivated grain, and plant matter than did females of the same
species. The females of both species ate significantly more wild seed than did
males. In addition, tricolor females ate significantly more insect matter than did
tricolor males.

Age Differences
For tricolors and red-wings, differences in consumption of the same six food
groups between age classes (adult vs. subadult) were less pronounced than
differences among species and between sexes (Table 3). For both species, the
two age classes ate almost identical percentages of rice and cultivated grain, but
subadult tricolors ate significantly more wild seed and significantly less insect
matter than did adults. For red-wings, there were no significant differences
between adults and subadults in consumption of wild seed, plant matter, beetles,
or insect matter.

BLACKBIRD FOOD SELECTION

263

TABLE 3. Sex and Age Differences in the Consumption of Selected Food Items (percent
of total annual volume, esophagi and stomachs combined) by Tricolored and Red-winged

Blackbirds.

Sex

Age

Food

item

Tricolored Red- winged Tricolored Red- winged

blackbird blackbird blackbird blackbird

Male Female Male Female Adult Subadult Adult Subadult

N= (143) (124) (230) (154) (224) (43) (329) (55)

Rice 47.6° 28.0' 49.5- 37.8>' 38.1° 37.5° 43.8' 43.6"

Cultivated grain 58.4° 38.0' 62.0' 46.2' 48.4° 49.0° 54.3' 53.9'

Wild seeds 22.3° 30.7' 26.2' 35.4' 18.8° 34.2' 29.2" 32.4'

Plant matter 79.4° 71.0' 87.7" 82.1' 65.2° 85.2' 83.4' 86.2'

Beetles 10.8° 13.0° 4.1' 5.7' 20.0° 4.8' 5.4' 4.4'

All insects 15.6° 20.8' 7.6' 9.6' 27.7° 8.7' 8.7' 8.5'

* Means compared using arcsin-transformed data. Within each food item and sex or age class, means followed
by different superscript letters are significantly different (p<0.05).

DISCUSSION

Potential Sources of Bias

Bartonek and Hickey (1969), Dirschel (1969), and Swanson and Bartonek
(1970) have shown differences in the food composition of esophagi and giz-
zards in several species of waterfowl, mostly because of differential retention
rates of hard and soft food items. Moreover, Beer and Tidyman (1942) showed
that gallinaceous birds use small, hard seeds as grit and Mott et al. (1972)
suggested that hard parts of insects (e.g., beetle mandibles) may also function
as grit in the gizzards of blackbirds.

In view of these findings, we conducted laboratory tests with tricolors and
found that relatively soft cultivated grains (rice and sorghum) are fully digested
within 2 to 4 hr, whereas harder wild seeds, such as water grass, are only about
50% digested at 8 hr. Small, very hard seeds of species such as smartweed
remain completely undigested after 1 2 hr. Swanson and Bartonek ( 1 970) recom-
mended that only esophageal contents be used in avian food habits studies. Such
a method would be impractical for blackbirds because they feed in many differ-
ent habitats and locations and may consume different foods at different times
of the day (Willson 1966). Esophageal contents in our study would largely reflect
only those foods eaten just before the birds entered the roost. Stomach contents,
on the other hand, would reflect the foods eaten earlier in the day but would
contain unrepresentative percentages of those most resistant to digestion.

In calculating the aggregate percent volume of foods eaten for Table 1, we
tried to lessen the above sources of bias associated with single-organ analyses
by averaging the esophageal and stomach contents together for each bird whose
esophagus contained food (all stomachs contained food). The resulting data
contain a slight to moderate bias toward stomach contents for each species
depending upon the proportion of birds with empty esophagi, but the bias is less
than with a single-organ analysis. For tricolors, red-wings, cowbirds, and yellow-
heads, 65, 77, 74, and 88% of the birds, respectively, had food in the esophagus.
Only 11% of the Brewer's blackbirds had food in the esophagus, however, so
the data for this species are the most heavily weighted toward stomach contents.

264 CALIFORNIA FISH AND CAME

Differential Food Selection

Lack (1954, 1966), Kear ( 1962), and Schoener (1965) have found that closely
related species of birds occupying the same area generally rely on different
foods. However, the presence of a super-abundant food supply can mask the
feeding differentiation evolved in natural systems (Lack 1954). Brown (1969)
has aptly pointed out that the food of wild birds is a compromise between what
they prefer and what is available.

In the Sacramento Valley, rice is a super-abundant food for much of the year.
In addition to thousands of acres of ripening rice available during late summer
and fall, large amounts of waste rice are available in fields during the winter and
perhaps into spring. Wild-growing blackbird foods, particularly water grass, are
kept at a minimum by the combination of rice monoculture and intensive agri-
cultural weed control programs. It is not surprising, therefore, to find rice as a
prominent food in the diet of blackbirds in the area. What is surprising is the large
amount of water grass eaten. It appears that cowbirds, and to a lesser extent the
other four species, must preferentially select or search for water grass for it to
be such a large portion of the annual diet. Despite the abundance of cultivated
grains, the many significant differences in food consumption show that the five
blackbird species have maintained a large degree of differential food selection.
Thus, it appears that mechanisms evolved in natural systems to subdivide the
food subniche are still operative, to some degree, in the agricultural environ-
ments created by modern man.

The actual mechanisms of feeding differences among bird species have been
shown to be related primarily to differences in bill size (which is related to body
size) and bill structure, which affect the size of seeds that can be handled
efficiently and the ease of catching insects (Kear 1962; Hespenheide 1966;
Newton 1967, 1973; Brown 1969; Willson 1971, 1972; Willson and Harmeson
1973). Differences in bill structure and size exist among all five blackbird species
we studied and, therefore, offer the best explanation of their feeding differences.
The finch-like bill of cowbirds is the most adapted for seed eating, and the longer,
thinner bills of red-wings, tricolors, and Brewer's blackbirds are more general-
ized for some insect gathering (Beecher 1951). Hence, cowbirds ate higher
percentages of seeds and fewer insects than did these other three species. Even
among congeneric species, bill structure apparently influences the diet. The
tricolor has a longer and thinner bill than that of the closely related red-wing
(Davis 1954, Orians 1961 ) and ate more insects than did the latter species. In
addition to structure differences, the bills of yellow-heads and red-wings are
larger than those of tricolors and Brewer's, whose bills are larger than the
cowbirds'. Thus, the cowbird may select more water grass than would the other
four species simply because the small water grass seeds are easier for it to handle
than the larger seeds of the cultivated grains.

Bill structure and size may also influence the feeding habits of tricolor and
red-wing sexes. Selander (1966) found that sex-related feeding differences in
woodpeckers [Centurus spp) were due to sexual dimorphism of the feeding
apparatus. In the tricolor and red-wing, females are smaller than males and have
smaller bills (Davis 1954, Orians 1961). This may explain why females ate
significantly more of the small wild seeds, and males more of the larger cultivat-
ed grains.

Differential habitat utilization may also account for some of the feeding differ-

BLACKBIRD FOOD SELECTION 265

ences among species and between sexes. Brewer's blackbirds, in particular, are
often found loafing and feeding along roadsides and other waste areas, whereas
the other four species are most often found in mixed-species flocks near fields,
marshes, or riparian situations. In addition, flock segregation by sex, which has
been reported at various seasons for yellow-heads (Willson 1966, Crase and
DeHaven 1972), red-wings (Meanley 1961, Orians 1961), tricolors (DeHaven
etal. 1975), and Brewer's (Bent 1958), may increase intersexual feeding differ-
ences if the male and female flocks, with their different bill sizes, forage in
different habitats.

Differences in size of bird and structure of bill do not adequately explain the
differential consumption of wild seeds and insects by subadult and adult tricolors
because the bill and other structures are generally full grown in passerines by
thefalland winter months (Marshall 1948, Power 1970). Brown (1969) suggest-
ed that young birds may inherit the ability to recognize food by certain cues,
such as seed color, size, and shape. However, such instinctual responses could
be modified by experience with other available foods (Newton 1973). There-
fore, young tricolors might recognize certain wild seeds as food but would have
to learn to eat the larger, cultivated grains. Proficiency in catching insects might
also be learned in that the more experienced an individual becomes, the more
adept he would be at successfully securing a food item that attempts escape.

Relationship To Agriculture

Our study shows changes in the diet of California's red-winged blackbirds
since earlier studies by Beal (1900) and Soriano (1931). They reported more
wheat and oats than we found; Beal did not mention rice and Soriano found only
small amounts. Beal also found a higher proportion of animal matter than we
did, but Soriano's figures were similar to ours.

Three factors likely account for most of these differences. First, the acreages
of the various grain crops have changed considerably. There was no cultivated
rice in California during Beal's studies in the late 1800's, and fewer than 40,500
ha (100,000 acres) in the 1930's. Rice is now one of the dominant grains in the
Sacramento Valley (Johnston and Dean 1969). Second, there have been con-
tinuing drainage and destruction of natural marsh areas, thereby reducing the
availability of native marsh foods. And last, the birds examined by Beal and
Soriano were from a larger geographic area and more varied habitats than were
the birds we examined.

The diet of Brewer's blackbirds in California as reported by Soriano (1931 )
was not as strikingly different from our data as that of the red-wing. We found
less wheat and filaree but more rice and water grass than did Soriano. Again,
differences in study areas and changes in agriculture probably account for most
of these differences.

Neff and Meanley ( 1 957 ) and Meanley ( 1 971 ) studied the foods of red-wings
and cowbirds in a situation similar to ours — the rice fields of Arkansas and
Louisiana. Rice was 45% of the red-wing's annual diet in Arkansas and 67% in
Louisiana. These proportions are similar to those we found for California red-
wings. However, rice was 46% of the brown-headed cowbird's annual diet in
Arkansas versus only 26% of our study.

The feeding differences between blackbirds of different species, sexes, and
ages mean that some groups are more responsible for agricultural damage than

266 CALIFORNIA FISH AND CAME

Others. Although we were primarily concerned with rice damage, the feeding
differences that we found likely exist in many, if not all, damage situations. Mott
et al. (1 972 ) , for example, found that red-wing males were responsible for more
corn damage in South Dakota than were females. However, selective control of
only the "damaging" groups would be practically impossible. Chemical repel-
lents such as methiocarb (Mesurol ") ( DeHaven et al. 1971,Guarino 1972, Crase
and DeHaven 1 976 ) offer the most promising method of safely protecting crops.
Since they simply render the crop unpalatable, they do not harm those birds not
causing damage and those that may actually be helping the farmer by consuming
large numbers of insects throughout much of the year.

ACKNOWLEDGMENTS
We thank W. Harry Lange and Lynn J. Shaw, University of California, Davis,
for help in the identification of insects and in the computer analysis of the data,
respectively. Bruce M. Browning, California Department of Fish and Game,
identified many of the seeds. We also thank co-workers Richard R. West, Paul
P. Woronecki, Joseph L. Guarino, Willis C. Royall, Jr., Jerome F. Besser, and Ann
H. Jones for help during various phases of the project.

REFERENCES

Bartonek, ). C, and ). ). Hickey 1969. Food habits of canvasbacks, redheads, and lesser scaup in Manitoba Condor
71(3): 280-290.

Beal, F.E.L. 1900. Food of the bobolink, blackbirds, and grackles. U.S. Dept. of Agr., Biol. Surv. Bull. No. 13. 77p.

Beecher, W. |. 1951. Adaptations for food-getting in the American blackbirds. Auk 68(4): 411-440.

Beer, ]., and W. Tidyman. 1942. The substitution of hard seeds for grit. J. Wildl. Manage. 6(1): 70-82.

Bent, A. C. 1958. Life histories of North American blackbirds, orioles, tanagers, and allies. U.S. Nat. Mus., Bull. 211.
549p.

Bird, R.D., and L. B. Smith. 1964. The food habits of the red-winged blackbird, Agelslus phoeniceus, in Manitoba.
Can. Field-Natur. 78(3): 179-186.

Brown, R.C.B. 1969. Seed selection by pigeons. Behavior 34(3): 115-131.

Bryant, H. C. 1912. Birds in relation to a grasshopper outbreak in California. Univ. Calif. Publ. Zool. 11(1): 1-20.

Crase, F. T., and R. W. DeHaven. 1972. Current breeding status of the yellow-headed blackbird in California. Calif.
Birds 3(2): 39^2.

1976. Methiocarb: Its current status as a bird repellent. Proc 7th Vert. Pest Cont. Conf., Monterey,

California. March 9-11. pp. 46-50.

— . 1977. Food of nestling tricolored blackbirds. Condor 79(2): 265-269.

Davis, J. 1954. Seasonal changes in bill length of certain passerine birds. Condor 56(3): 142-149.

DeHaven, R. W., F. T. Crase, and P. P. Woronecki. 1975. Breeding status of the tricolored blackbird, 1969-72. Calif.
Fish Came 61(4): 166-180.

DeHaven, R. W., |. L. Guarino, F. T. Crase, and E. W. Schafer, )r 1971. Methiocarb for repelling blackbirds from
ripening rice. Int. Rice Comm. Newsletter 20(4): 25-30.

Dirschel, H. ). 1969. Foods of lesser scaup and blue-winged teal in the Saskatchewan River Delta. ). Wildl. Manage.
33(1): 77-87.

Guarino, J. L. 1972. Methiocarb, a chemical bird repellent: a review of its effectiveness on crops. Proc. 5th Vert.

Pest Cont. Conf., Fresno, California. March 7-9. pp. 108-111.
Hespenheide, H. A. 1966. The selection of seed size by finches. Wilson Bull. 78(2): 191-197.

Hintz, |. v., and M. I. Dyer. 1970. Daily rhythm and seasonal change in the summer diet of adult red-winged

blackbirds. ). Wildl. Manage. 34(4): 789-799.
Johnston, W. E., and C. W. Dean. 1969. California crop trends: yields, acreages, and production areas. Univ. Calif.

Agr. Exper. Sta., Ext. Service Circ. 551. 126p.

Kear, J. 1962. Food selection in finches with special reference to interspecific differences. Proc. Zool. Soc. London
138: 163-204

Lack, D. 1954. The natural regulation of animal numbers. Oxford Univ. Press, London. 343p.

1966. Population studies of birds. Oxford Univ. Press, London. 341 p.

BLACKBIRD FOOD SELECTION 267

Marshall, J. T, )r 1948. Ecologic races of song sparrows in the San Francisco Bay region. Part M. Geographic
variation Condor 50(6): 233-256.

Meanley, B 1961. Late-summer food of red-winged blackbirds in a fresh tidal-river marsh. Wilson Bull. 73(1):

36-^0.

1971. Blackbirds and the southern rice crop. U.S. Fish and Wildl. Service, Resource Publ. 100 64p.

Mott, D. F., R. R. West, J. W. DeCrazio, and J. L. Cuarino. 1972. Foods of the red-winged blackbird in Brown

County, South Dakota. J. Wildl. Manage. 36(3): 983-987.

Neff, J. A., and B. Meanley. 1957. Blackbirds and the Arkansas rice crop. Arkansas Agr. Exper. Sta., Bull. No. 584.
89p.

Newton, I. 1967. The adaptive radiation and feeding ecology of some British finches. Ibis 109(1 ): 33-98.

1973. Finches. Taplinger Publ. Co., New York. 288 p.

Orians, G. H. 1961. The ecology of blackbird (Agelalus) social systems. Ecol. Monogr. 31(3): 285-312.

Power, D. M. 1970. Geographic variation of red-winged blackbirds in central North America. Univ. Kansas Mus.
Natur. Hist. 19(1): 1-83.

Schoener, T. W. 1 965. The evolution of bill size differences among sympatric congeneric species of birds. Evolution
19(2): 189-213.

Selander, R. K. 1966. Sexual dimorphism and differential niche utilization in birds. Condor 68(2): 113-151.

Soriano, P. S. 1931. Food habits and economic status of the Brewer and red-winged blackbirds. Calif. Fish Game
17(4): 361-395.

Swanson, C. A., and J. C. Bartonek. 1970. Bias associated with food analysis in gizzards of blue-winged teal. J. Wildl.

Manage. 34(4): 739-746.
Willson, M. F. 1966. Breeding ecology of the yellow-headed blackbird. Ecol. Monogr. 36(1): 51-77.

1971. Seed selection in some North American finches. Condor 73(4): 415^29.

1972. Seed size preference in finches. Wilson Bull. 84(4): 449—455.

Willson, M. F., and ). C. Harmeson. 1973. Seed preferences and digestive efficiency of cardinals and song sparrows.
Condor 75(2): 225-234.

268

Calif. Fish and Came 64 ( 4 ) : 268-279 1 978

THE INFAUNA OF A SUBTIDAL, SAND-BOTTOM
COMMUNITY AT IMPERIAL BEACH, CALIFORNIA ^

DEBORAH M. DEXTER

Department of Zoology
San Diego State University
San Diego, California 92182

The infauna characteristic of shallow subtidal sand bottoms was surveyed season-
ally during 1976 at Imperial Beach, California. A total of 5,916 individuals was collect-
ed and 131 species were represented. Among the most important contributors to the
density were the amphipods, Eohaustorius washingtonianus and Paraphoxus epis-
tomus, the isopod, Ancinus granulatus, the gastropod, Olivella baetica, and the sand
dollar, Dendraster excentricus. Comparison of current community composition with
that of a previous study indicates considerable stability or persistence of the fauna.

INTRODUCTION

Although subtidal sand habitats are extensive along the southern California
coastline, the inshore sand habitat is not well studied, probably because of the
difficulty of sampling within the surge zone. Pager's (1968) study is the only
published quantitative account of a shallow water epifaunal sand community in
southern California. A major survey of the southern California mainland shelf
was undertaken by the Allan Hancock Foundation in 1959 in cooperation with
several State of California agencies. Although the major emphasis of that study
concerned the offshore fauna on the continental shelf, some samples were taken
in the inshore environment (California State Water Quality Control Board 1965;
Jones 1969; Southern California Coastal Water Research Project 1973). Only a
few samples were taken at any one locality, but some information is available
on infaunal organisms living at depths of 3 to 10 m along the southern California
coastline.

The present study was part of a larger survey of the marine communities
located at Imperial Beach, California (Dexter 1977), which was conducted for
the U.S. Army Corps of Engineers (Project DAC 09-76-M-1323). The subtidal
sand sediment was found to contain a diverse and persistent community of
organisms which was maintained seasonally and spatially.

METHODS

Four transects were selected as sampling sites in the subtidal sands off Imperial
Beach. These transects were identified as Elkwood, Surfside, Carnation, and
Radio. Elkwood transect was located at the foot of Elkwood Street about 100 m
south of the Imperial Beach Pier. Surfside, at the foot of the Surfside Motel, was
located about 175 m north of the Imperial Beach Pier. Carnation, at the foot of
Carnation Street, was located between two existing intertidal rocky groins, and
about 500 m north of the Imperial Beach Pier. Radio was located about 750 m
north of the Imperial Beach Pier off the U.S. Naval Radio Facility.

The transects were sampled seasonally during 1976 at depths of 3, 4, 5, 6, and
7.5 m (surge conditions permitting) . Winter sampling was conducted on January

' Accepted for publication January 1977.

INFAUNA OF A SUBTIDAL COMMUNITY 269

31 and February 1; spring samples were collected on April 24; summer samples
on July 21 ; and fall samples on October 1 7. The subtidal sand fauna was surveyed
quantitatively by divers using scuba and an airlift sampler (Chess 1969). The
airlift sampler is a diver-operated vacuum collecting device for sampling the
benthic macrofauna. The winter samples were obtained using a Nitex vacuum
bag of 760-ju. mesh while later samples were obtained with a vacuum bag of
1,000-ja mesh. This change was made because of the extensive time required to
sort the collections made with the smaller mesh bags.

A stainless steel cylinder 0.25 m^ in circular surface area was pushed into the
sand at each station. The airlift sampler was used to remove all sediment to a
depth of 20 cm below the surface within the cylinder. A small sediment core was
taken to a depth of 10 cm at each station for sediment analysis.

The sediment and organisms retained in the vacuum bags were preserved in
a 5% solution of formalin in seawater. In the laboratory the organisms were
sorted to major phyla and blotted wet weights were determined for each major
group. The organisms were identified to species and number of individuals of
each were counted. Sediment grain size was analyzed with an Emery settling
tube (Emery 1938).

On October 17, 1976, a separate collection was made to sample the size-
frequency distribution of the sand dollar, Dendraster excentricus, which was not
accurately sampled with the airlift sampler. A stainless steel cylinder 0.1 m^ in
surface area was pushed into the sand in the section of the sand dollar bed along
each transect where density of individuals was highest. All individuals of D.
excentricusW\'&\\u each sample were removed and later their length was meas-
ured to the nearest mm. The length was determined as the distance from margin
to margin of the test in a line through IIU, the apical system, and lunule 5,.

Species diversity was determined using the Shannon-Wiener diversity index
(Lloyd and Ghelardi 1964) for each transect during each season (all depths
combined), for each depth at each season (all transects combined), and for
each seasonal collection (data pooled for all transects and all depths within a
given season). Coefficients of community (Whittaker 1956) were calculated to
compare between transect, between depth, and within transect similarity for
within season and between season samples. The coefficient of community, an
expression of the degree of similarity between two or more samples, ranges from
0 for samples having no species in common to 1.0 for samples identical both in
species composition and in quantitative value for the species.

RESULTS

A total of 60 quadrats was collected from a sample area of 15.0 m^, from
which 5,916 individuals representing 131 species were collected. The average
density of the fauna was 394/m2. The total wet weight of the collected organisms
was 446.7 g, averaging 29.8 g/m^

Complete data for individual samples along all transects during all seasons are
presented by Dexter ( 1 977 ) in the technical report which is available at the San
Diego State University library.

The fauna was dominated by polychaetes and arthropods which contributed
53% and 26%, respectively, of the total number of individuals (Table 1). In
addition, more than 70% of the species were in these two taxonomic groups.
The echinoderms, particularly Dendraster excentricus, were the largest contribu-

270

CALIFORNIA FISH AND CAME

tor to the biomass, forming 44% of the total; the second major contributors to
biomass were the arthropods, which composed 26% of the total.

TABLE 1. Faunal Composition of Subtidal Sands off Imperial Beach, California, Based on

Seasonal Sampling in 1976.

Number of
Taxon individuals

Cnidaria

Renllla kolllkeri 3

Nemertea 269

Sipunculida 4

Polychaeta

Analtides multiseriata 1

Aricidea sp 7

Axiothella rubrocincla 2

Capitellidae 7

Capitita ambisecta 1

Chaetozone corona 12

Chaetozone s[> 4

Chone mollis 2

Glycera capitata 11

Clycera sp 7

CIvcera tenuis 30

Glycera tesselata 5

Clycinde armigera 1

Goniada littorea 85

Hemipodus borealls 2

Hesperone^p 3

Lumbrineris pallida 91

Lumbrinens tetraura 9

Magelona pitelkai 182

Nephtys caecoides 75

Nephtys califomiensis 18

Nephtys sp 3

Nereis latescens 5

Notomaslus tenuis 43

Onuphis vexillaria 59

Ophelia limacina 1

Ophiodroma pugettensis 5

Owenia collaris 1

Pareurvthoe sp 25

Pectinaria califomiensis 7

Pista elongatus 1

Polvdora sp 1

Polynoidae 20

Prionospio cirrifera 7

Prionospio pvgmeus 67

Rhynchospio arenicola 172

Scolelepis acuta 101

Scolelepis folliosa 1

Scoloplos armiger 209

Sigalionidae 1

Spiophanes missionensis. 2

Density Occurrence Percent
Ino./m^l I no. /60 quadrats! composition

17.9

44
1

4.55

2.0

18
3
1

5.7

21
2
2

1.44

6.1

1.54

12.1

3.08

5.0

1.27

1.2

6
3
2

2.9

3.9

27
1
4

1.00

1.7

5
1
1

1.3

4.5

1.13

11.5

2.91

6.7

1.71

13.9

27
1
2

3.53

INFAUNA OF A SUBTIDAL COMMUNITY 271

Sthenelais verruculosa 10 6

Thalanessa spinosa 142 9.5 32 2.40

Tharyx multifilis 3 2

Typosyllis armillaris 3 2

Typosy//issp 43 2.9 11

Mollusca, Gastropoda

Acteocina harpa 1 1

Astrea gibberosa 1 1

Bald's sp 2 2

BIttium sp 2 2

Caecum californicus 1 1

Crepidula sp 3 1

Mitrella carinata 3 2

Nassarius fossatus 39 2.6 8

Nassarius perpinguis 2 2

Olivella baetica 222 14.8 18 3.75

Olivella biplicata 18 1.2 12

Ophiodermella sp 1 1

Polinices reclusiana 47 3.1 18

Turbonilla regina 1 1

immature gastropod A 4 4

nudibranch A. 1 1

Mollusca, Bivalvia

Bornea retifera 16 1.1 4

Chione californiensis 1 1

Cryptomya californica 177 11.8 11 2.99

Donax gouldii 7 3

Entodesma saxicola 1 1

Lucina nuttallii 1 1

Macoma sp A 1 1

A^tJfomc? sp B 10 3

Macoma sp C 1 1

Myteliidae 1 1

Siliqua lucida 1 1

Solen sicarius 3 2

Tellina bodegensis 1 1

Tellina carpenteri. 53 3.5 16

immature sp A 4 2

immature sp B 4 3

immature sp C 1 1

Echinodermata, Echinoidea

Dendraster excentricus 209 13.9 31 3.53

Echinodermata, Ophiuroidea

Amphipodia digitata 24 1.6 12

Amphipodia occidentalis 4 4

Amphipodia urtica 7 3

Echinodermata, Holothuroidea

Synaptidae 3 1

272 CALIFORNIA FISH AND CAME
Hemichordata

Saccoglossus 11 9

Arthropoda, Pycnogonida

species A 2 2

species B 1 1

species C 1 1

Arthropoda, Crustacea

Copepoda 3 3

Ostrocoda

Euphilomedes carcharodonta 456 30.4 18 7.71

Mysidacea

Archeomysis maculata 58

unidentified 1

Cunnacea

Diastylopsis tenuis 133

Leptocuma forsmani 163

Isopoda

Ancinus granulatus 275

Edotea sublittoralis 11

Halisphasma geminata 3

Idothea fewkewsi 1

Synidotea harfordi 1

Synidotea sp n 3

Amphipoda

Amphilhoe sp 1

Aorides columbiae 10

Atylus tridens 94

Caprellidae 1

Elasmopus sp 1

Eohaustorius washingtonianus 1029

Cammaropsis thompsoni 1

Hyalidae 4

Listriella melanica 2

Mandibulophoxus gilesi 242

Megaluropus longimerus 2

Paraphoxus epistomus 421

Photis califomica 1

Photis sp 2

Synchelidium shoemakeh. 43

Synchelidium sp 2

Decapoda, Natantia

Alpheus dentipes 3

Umcarii infraspinis 46

Decapoda, Reptantia

Blepharipoda occidentalis 1

brachyuran megalops 6

Callianassa gigas 32

Cancer gracilis 2

Cancer jordani 16

IHolopagurus pilosus 7

Lepidopa myops 48

Pinnixa barnharti 101

Pinnixa sp 64

Portunus xantusi 1

3.9

8.9

2.25

10.9

2.76

18.3

4.65

6.3

1.59

68.7

17.39

16.1

4.09

28.1

7.12

2.9

3.1

2.1

3.2

6.7

1.71

4.3

1.08

INFAUNA OF A SUBTIDAL COMMUNITY 273

Of the 131 species present, only 24 individually contributed 1% or more of
the composition by density. Eight of these also occurred in 50% or more of the
quadrats. These dominant species include the polychaetes Magelona pitelkai,
Rhynchospio arenicola, and Thalanessa spinosa; the sand dollar, Den d raster
excentricus; the cumacean, Leptocuma tenuis; the isopod, Ancinus granulatus;
and the amphipods, Eohaustorius washingtonianus and Paraphoxus
epistomus. Five additional species had a density greater than lO/m^, but oc-
curred less frequently: the polychaete, Scoloplos armiger, the bivalve, Cryp-
tomya californica, the gastropod, Olivella baet/ca; the ostrocod, Euphilomedes
carcharodonta; and the amphipod, Mandibulophoxus gilesi. These 13 species
comprised 70% of all individuals collected from the subtidal sands off Imperial
Beach.

The sand dollar, Dendraster excentricus, was the largest contributor to the
biomass of the subtidal sand fauna. Although the density of D. excentricus
averaged M/m^ throughout the study area, the average density v^ithin the sand
dollar bed was 1,210/m2. The airlift sampler collected only smaller individuals
(Figure 1 ). Size frequency distributions of organisms collected by hand (Figure
1 ) show changes in population size structure along Imperial Beach. There was
no significant difference in the mean size of sand dollars along the Radio and
Carnation transects, but a significant decrease (p< 0.001) in the mean size of
the population occurred from the southernmost transect to these northernmost
transects, based on the results of a Kolmogorov-Smirnow two sample test ( Siegel
1956).

Synthesis of the number of species found, density of individuals, biomass,
median sediment grain size, and the Shannon-Wiener diversity index in relation
to transect location and depth were conducted (Table 2). No obvious differ-
ences in community structure are evident among the four transect locations.
However, there are clear differences in the structure of the community with
depth. The major changes include an increase in the number of species, an
increase in the density of individuals, and an increase in diversity (as measured
by the Shannon-Wiener index) with increasing depth. Sediment particle size
decreased with increasing water depth, but at all depths can be classified as fine
or very fine sand.

A summary of the coefficient of community values indicating similarity
between samples was computed (Table 3 ) . Indices of similarity averaged 0.2409
for within transect similarity and 0.3173 for between depth similarity, indicating
greater differences within a transect than between depths during the same
season. When the data from each seasonal sample were compared to all other
seasonal samples (between season variation), the average coefficient of com-
munity was 0.4559. A relatively high seasonal similarity of 46% in faunal compo-
sition and abundance indicates that a single community of organisms occurred
throughout the study area.

DISCUSSION

Community Composition

Thirteen species were characteristic of the subtidal sand fauna. The haustoriid
amphipod, Eohaustorius washingtonianus, was the most abundant species in the
Imperial Beach subtidal sand community. It was found from the low intertidal

274

CALIFORNIA FISH AND CAME

40
30

10
0
30
20
10
0

30
20
10

0
30
20

13.4 ±

Surfside
N = 99

1.6

Airlift Sample
N = 37

I I

Radio
N=137

I 36.0

0.8

1 1

Carnation

35.9

0.8

- N=188

1 —

— 1

46.5 ± 1.3

Elkwood
N = 65

57.6 ± 0.6

ee-zd

0-5 ' 6 lO'l 1 -15'16-20'21 -25'26-30'31 -35'36-40'41 -4 5'46-50

51-55

56-60

61 -65

Test Length in mm

FIGURE 1 Size frequency histograms of Dendraster excentricus collected along each transect on
October 17, 1^76, compared to total sample collected October 17 with airlift sampler. Mean size
and standard error are indicated.

INFAUNA OF A SUBTIDAL COMMUNITY

275

TABLE 2.

A. Comparison of Shannon-Weiner Diversity Index Between Transect Locations and

Between Depths During 1976 at Imperial Beach, California.

^ason

Depth

in meters

Transect locations

3.0

4.5

6.0

7.5

Elkwood

Suiiside

Carnation

Radio

Winter

n.s.

3.78

4.37

4.03

4.24

3.98

4.37

4.20

Spring

n.c.

4.58

n.c.

4.13

n.c.

Summer

n.c.

3.98

4.25

4.70

4.16

4.34

4.83

5.03

Fall

n.c.

2.50

4.05

3.55

4.10

4.13

3.58

3.65

n.s. = not sampled, n.c. = not calculated. Diversity index was not calculated when less than 200 individuals were
collected in a sample.

B. Comparison of Number of Species Present Between Transect Locations and Between

Depths.

?ason

Dep

ths

Transect ,

locations

3.0

4.5

6.0

7.5

Elkwood

Surfside

Carnation

Radio

Winter

n.s.

Spring

Summer

Fall

C. Comparison of Density of Individuals (no./m^) Between Transect Locations and

Between Depths.

?ason

Z?ev

oths

Transect locations

3.0

4.5

6.0

7.5

Elkwood

Surfside

Carnation

Radio

Winter

n.s.

891

671

916

348

1411

760

785

Spring

135

489

158

147

336

119

Summer

122

280

364

301

129

394

300

244

Fall

175

350

249

837

404

365

508

334

D. Comparison of Biomass (grams/m^) Between Transect Locations and Between Depths.

"ason

Det

oths

Transect .

locations

3.0

4.5

6.0

7.5

Elkwood

Surfside

Carnation

Radio

Winter

n.s.

116.5

48.1

24.4

34.8

70.5

82.3

64.4

Spring

3.0

69.0

7.6

127.0

43.1

11.6

60.8

11.4

Summer

24.5

7.0

12.5

15.5

14.5

13.0

22.4

9.7

Fall

2.8

9.5

26.7

32.2

22.4

20.8

19.9

8.1

E. Comparison of Sediment Median Grain Size in Microns Between Transect Locations

and Between Depths.

"•ason

Def

oths

Transect ,

locations

3.0

4.5

6.0

7.5

Elkwood

Surfside

Carnation

Radio

Winter

142

123

113

115

135

115

117

122

Spring

188

184

126

128

160

180

146

139

Summer

165

185

134

121

113

151

165

176

Fall

163

159

123

108

125

146

130

seaward, but only became abundant at 4.5 m or deeper. The species is distribut-
ed along the southern California coastline (Barnard 1957).

Along the eastern coast of the United States, both in intertidal and subtidal
sand communities, haustoriid amphipods dominate the sand communities
(Croker 1967; Dexter 1967, 1969, 1971; Croker, Harger, and Scott 1975; Holland

276

CALIFORNIA FISH AND CAME

TABLE 3. A Comparison of Coefficients of Community for the
Subtidal Sand Fauna at Imperial Beach, California.

A. Similarity within transects

Season

Elkwood

Surfside

Carnation

Radio

Winter

.1751

.3437

.3712

.3910

Spring

.1724

.1733

.2406

.1741

Summer

.1860

.2371

.2185

.1781

Fall

.2531

.2428

.2688

.2551

B. Similarity between depths

3.0 m

4.5 m

6.0 m

7.5 m

3.0 m

4.5 m

.3621

6.0 m

.2399

.4217

7.5 m

.1694

.3058

.3672

C. Similarity within transects

Elkwood

Surfside

Carnation

Radio

Elk wood

Surfside

.4738

Carnation

.4371

.5319

Radio

.3886

.5826

.5253

D. Similarity between seasons

Winter

Spring

Summer

Fall

Winter

Spring

.3768

Summer

.4728

.3103

Fall

.4774

.4757

.6221

and Polgar 1976; Sameoto 1969d, 1969^). West coast studies have not shown
haustoriid amphipods to be important members of the intertidal beach commu-
nity, except in some tropical beaches (Dexter 1974). Their contributions to the
subtidal sand communities are not well documented, perhaps due to the
scarcity of pertinent studies. Much more attention should be focused on these
abundant, filter feeding amphipods and their role in the shallow subtidal
sands along the southern California coastline should be determined.

Two other dominant species were also amphipods, Paraphoxus epistomus
and Mandibulophoxus gilesi, both of which belong to the family Phoxoceph-
alidae. Phoxocephalid amphipods are characteristic of both intertidal and sub-
tidal sand substrates. P. espistomus occurs in the western Atlantic Ocean and
in the eastern Pacific Ocean from Puget Sound to the Gulf of California ( Barnard
1960). At Imperial Beach its abundance increased with depth. M. gilesi hdLS an
interesting geographical distribution, occurring both in the Indian Ocean along
Sri Lanka and the Madras coast and along the southern California coastal shelf
(Barnard 1960). At Imperial Beach, M. gi/esi was aggregated in the surge zone
at 4.5 m.

The largest contributor to the biomass at Imperial Beach was the sand dollar,
Dendraster excentricus. This filter feeding echinoid occurs in the eastern Pacific
Ocean from Baja California to Alaska; several aspects of its biology have been

INFAUNA OF A SUBTIDAL COMMUNITY 277

Studied (Niesen 1969; Merrill and Hobson 1970; Birkeland and Chia 1971; Timko
1975). At Imperial Beach, D. excentricus was nnost abundant in the surge zone.
Observations on the size structure of D. excentricus (Figure 1) indicate that
successful recruitment has occurred continuously during the past several years
at Imperial Beach. Timko (1975) estimates that D. excentricus reach an average
diameter of 21 mm at 1 year of age, 32 mm at 2, 47 mm at 3, and that individuals
4 years or older are 60 mm or larger. If her estimates of age are correct, then
successful recruitment of new individuals has occurred yearly from 1972 through
1975 in the areas of Radio and Carnation transects, and in 1972, 1973, and 1975
at Surfside. Recruitment in the area of the Elkwood transect apparently was
successful only in 1972 and 1973. Current observations from airlift samples
indicate the presence of the 1976 age class along all transects. However, future
studies would have to be conducted to determine whether this age class persists
and is successful. The aggregations of D. excentricus a\. Imperial Beach are the
largest seen by the biologists involved in this study at any location in San Diego
County over the past 10 years.

Four polychaetes were among the most abundant species. They are: Magelo-
na pitelkai (Magelonidae), Rhynchopsio arenicola (Spionidae), Scoloplos ar-
miger (Orbiniidae), and Thalanessa spinosa (Sigalionidae). Hartman (1969)
reports that S. armiger occurs in littoral depths off southern California and
western Europe; M. pitelkai and R. arenicola are common in central and south-
ern California. T. spinosa is also distributed along central and southern California
(Hartman 1968). Magelonid and spionid polychaetes are surface deposit feed-
ers while orbiniids directly ingest the substrate as they burrow. M. pitelkai, R.
arenicola, and T. spinosa increased in abundance with depth at Imperial Beach,
while S. armiger had its peak abundance in the surge zone.

The isopod, Ancinus granulatus, was most abundant in the subtidal sand at
Imperial Beach but also occurred in the intertidal. A. granulatus occurs along the
California coast and in the Gulf of California (Glynn and Glynn 1974) . Although
species of Ancinus are among the most abundant species in tropical American
beach communities (Dexter 1972, 1974), they have not been reported as abun-
dant in temperate American beaches.

The cumacean, Leptocuma forsmani, was distributed from the surf zone out-
ward and increased in abundance with depth. L. forsmani occurs along the
western coast of North America (Zimmer 1943). The ostrocod Euphilomedes
carcharodonta was very abundant in the winter samples when the smaller mesh
collecting bag was used. During the remainder of the study, when the 1,000-ja
mesh bag was used, the species was collected infrequently. The majority of
individuals were collected from the surge zone. £ carcharodonta is found along
the coast of California to Canada (Smith 1952). Presumably, when more work
is done on the meiofauna of the subtidal sands, the contributions of this species
will be recognized.

The gastropod, Olivella baetica, occurs from southern Alaska to Baja Califor-
nia (Morris 1966) and at Imperial Beach was most abundant in the surge zone.
The bivalve, Cryptomya californica, occurs from Alaska to northern Peru (Keen
1971) and is often associated with burrowing shrimp. At Imperial Beach its
abundance increased with depth.

278 CALIFORNIA FISH AND CAME

Faunal Similarity

Based on the results of this study, the fauna of the subtidal sands off Imperial
Beach can be considered as a single community. Highest similarity in faunal
composition and abundance occurred between transects; lower similarity was
observed between depths. The lowest coefficients of community were seen
when within transect stations were compared. Similarity values within and
between depths were comparable for each sample date and for seasonal sam-
ples, indicating no marked seasonal change. Discrete communities were not
present, but a continuum of changes occurred through both season and space.

The fauna of the Imperial Beach subtidal sands is typical of the inshore area
of southern California. San Diego Gas and Electric (1973) lists only 19 species
of invertebrates occurring in a similar sand bottom area at depths of 7.5 m or
less off the Encina Power Plant, Carlsbad, California, of which nine were shared
in common with the study site described here. The California State Water
Quality Control Board (1965) lists a total of 61 species of invertebrates taken
in 3 to 10 m of water in the sandy subtidal along the coastline of California. Of
these, 14 species were collected at Imperial Beach in the present study, and 23
additional genera were shared in common by the two studies.

Stability of Faunal Composition
The composition of the infauna off Imperial Beach is quite stable or persistent.
In 1959, a single Van Veen grab sample was taken in 9 m of water off Imperial
Beach (Station #6418-59; California State Water Quality Control Board 1965).
A total of 40 species was taken, of which all but six genera and three unidentified
species (representing only 9% of all the individuals) also were collected during
the present Imperial Beach study. The dominants in 1959 included three poly-
chaetes (Coniada littorea, Prionopsio malmgreni, and Spiophanes bombyx) ,
one gastropod {Olivella baetica) , one bivalve ( Tellina buttonf) , one cumacean
[Diastylopsis tenuis), and two amphipods iParaphoxus bicuspidatus and P.
epistomus) . Two of these species were among the 13 dominant species in 1976,
two other species were collected in 1976, and three additional genera were
shared in common. Considering that the samples were made 1 7 years apart, with
different sampling techniques, and at slightly different water depths, the similar-
ity in the fauna is remarkable. Thus, the evidence obtained in this study indicates
that the subtidal sands off Imperial Beach contain a stable and diverse fauna.

ACKNOWLEDGMENTS

Persons providing technical assistance in field and laboratory work and those
responsible for species identification are listed in the technical report (Dexter
1977). The manuscript has benefited from critical examination by R. F. Ford.
Contribution No. 30 from San Diego State University, Center for Marine Studies.

REFERENCES

Barnard, J. L. 1957 A new genus of haustoriid amphipod from the northeastern Pacific Ocean and the southern
distribution of Urothoe vdi/a/'//?/ Curjanova. So. Calif. Acad. Sci., Bull., 56:81-84.

1960. The amphipod family Phoxocephalidae in the Eastern Pacific Ocean, with analyses of other species

and notes for a revision of the family Allan Hancock Pac. Exped., 18:175-368.

Birkeland, C, and F. S. Chia. 1971. Recruitment risk, growth, age, and predation in two populations of sand dollars,
Dendraster excentricus (Eschscholtz). J. Exp. Mar. Biol. Ecol., 6:265-278.

INFAUNA OF A SUBTIDAL COMMUNITY 279

California State Water Quality Control Board. 1965. An oceapographic and biological survey of the southern

California mainland shelf. Pub. 27, 282 p. Appendix, 446 p.
Chess, J. R. 1969. An airlift sampling device for benthic organisms. Westinghouse Research Lab. Res. Memo,

69-151-OCEAN-M1:1-9

Croker, R. A. 1967. Niche diversity in five sympatric species of intertidal amphipods (Crustacea: Haustoriidae).
Ecol. Monogr., 37:173-200.

Croker, R. A., R. P. Harger, and K. |. Scott. 1975. Macroinfauna of northern New England marine sand. II.

Amphipod-dominated intertidal communities. Can. |. ZooL, 53:42-51.
Dexter, D. M. 1967, Distribution and niche diversity of haustoriid amphipods in North Carolina. Ches. Sci.,

8:187-192.

1969. Structure of an intertidal sandy-beach community in North Carolina. Ches. Sci., 10:93-98.

1971 . Life history of the sandy-beach amphipod, Neohaustorisu schmitzi (Crustacea: Haustoriidae) . Mar.

Biol. 8:232-237.

1 972. Comparison of the community structures in a Pacific and an Atlantic Panamanian sandy beach. Bull.

Mar. Sci., 22: 449-462.

1974. Sandy-beach fauna of the Pacific and Atlantic coasts of Costa Rica and Columbia. Rev. Biol. Trop.,

22:51-69.

1977. Biological baseline studies of the Imperial Beach Erosion Control Project Area. Final Report for U.S.

Army Corps of Engineers on Project DAC09-76-M-1323. 160 p.

Emery, K. O. 1938. Rapid method of mechanical analysis of sands. I. Sediment. Petrol., 8:105-111.

Fager, E. W. 1968. A sand-bottom epifaunal community of invertebrates in shallow water. Limnol. Oceanogr.,
13:449-^64.

Glynn, P. W., and C. S. Glynn. 1974. On the systematics of Ancinus (Isopoda, Sphaeromatidiae), with the
description of a new species from the tropical eastern Pacific. Pac. Sci., 28:401^22.

Hartman, O. 1968. Atlas of the errantiate polychaetous annelids from California. Allan Hancock Found. 828 p.

1969. Atlas of the sedentariate polychaetous annelids from California. Allan Hancock Found. 812 p.

Holland, A. F., and T. T. Polgar. 1976. Seasonal changes in the structure of an intertidal community. Mar. Biol.,
37:341-348.

Jones, C. F. 1969. The benthic macrofauna of the mainland shelf of southern California. Allan Hancock Monogr.
in Mar. Biol., 4:1-219.

Keen, M. A. 1971. Sea shells of tropical west America. Stanford University Press. 1064 p.

Lloyd, M., and R. ). Ghelardi. 1964. A table for calculating the 'equitability' component of species diversity. ). Anim.

Ecol., 33:217-225.
Merrill, R. J., and E. S. Hobson. 1970. Field observations of Dendraster excentricus, a sand dollar of western North

America. Amer. Midi. Nat., 83:585-624.

Morris, P. A. 1966. A field guide to shells of the Pacific coast and Hawaii. Houghton Mifflin Co. 297 p.

Niesen, T. M. 1969. Population structure, dynamics, breeding cycles, and ecotypic variation in San Diego popula-
tions of the sand dollar Dendraster excentricus (Eschscholtz). MS. Thesis, San Diego State Univ. 241 p.

Sameoto, D. D. 1969d. Comparative ecology, life histories, and behaviour of intertidal sand-burrowing amphipods
(Crustacea: Haustoriidae) at Cape Cod. Canada, Fish. Res. Bd., J., 26:361-388.

19696. Some aspects of the ecology and life cycle of three species of subtidal sand-burrowing amphi-
pods (Crustacea: Haustoriidae). Canada, Fish. Res. Bd., ]., 26:1321-1345.

San Diego Gas and Electric Company. 1 973. Thermal distribution and biological studies for the Encina Power Plant.
Final Report, Vol. 5. Not numbered.

Siegel, S. 1956. Non parametric statistics for the behavioral sciences. McGraw Hill Book Co. 312 p.
Smith, V. Z. 1952. Further ostrocoda of the Vancouver Island region. Canada, Fish. Res. Bd., )., 9:16--41.
Southern California Coastal Water Research Project. 1973. The ecology of the southern California Bight: implica-
tions for water quality management. 531 p.

Timko, P. L. 1975. High density aggregations in Dendraster excentricus (Eschscholtz): Analysis of strategies and
benefits concerning growth, age structure, feeding, hydrodynamics, and reproduction. Ph.D. Thesis, Univ. of
Calif, at Los Angeles. 323 p.

Whittaker, R. H. 1956. Vegetation of the great smoky mountains. Ecol. Monogr., 26:1-80.

Zimmer, C. 1943. Cumaceen des stillen ozeans. Arch. Naturgesch. 12:130-173.

280

Calif. Fish and Came 64 ( 4 ) : 280-301 1 978

CALIFORNIA OCEAN SHRIMP MESH EXPERIMENT ^

NANCY C.H. LO-'

Operations Research Branch

California Department of Fish and Came

Shrimp net mesh size data obtained from a Department cruise made in 1956
between Point Reyes and the mouth of the Russian River, California, were re-exam-
ined. A proportional sampling scheme was used to obtain the maximum likelihood
estimator (MLE) of the catch ratio. A comparison of shrimp escapement between
five beam trawl cotton nets of different mesh sizes was made. Mesh sizes of five nets,
after shrinkage, were 3.6, 4.1, 4.2, 4.3, and 4.7 cm (1.43, 1.60, 1.62, 1.66 and 1.84 inches),
respectively. An average escapement rate ( AER) for any age group was derived and
used to compare differences between the test mesh sizes. AER's for mesh sizes 3.4,
3.8, and 3.9 cm (1.34, 1.50, and 1.55 inches) were estimated. Also, comparisons of
catch per hour adjusted by the footage of head rope (CHF) were made of four
commercial otter trawl nylon nets with mesh sizes ranging from 3.7 to 3.9 cm (1.44
to 1.54 inches). The mesh size of 3.8 cm (1.50 inches) is recommended.

INTRODUCTION

Ocean shrimp, Pandalus jordani, support one of the youngest commercial
fisheries of California (Dahlstrom 1972). Commercial quantities of this species
were first fished off Morro Bay in April 1952. Thereafter, two other major shrimp
beds along the California coast were fished. Three regulatory areas were desig-
nated and catch quotas established for each (Figure 1 ). Mesh size regulations
were imposed and catch quotas and a season were established.

Area A contains the largest shrimp bed and produces most of the shrimp
landed in California. Shrimp landings in Area A climbed from 340,000 kg (750,-
000 lb) in 1957 to 840,000 kg ( 1.86 million lb) in 1963. Catches declined to under
450,000 kg (1 million lb) in 1964, but increased to the peak of 1.63 million kg
(3.6 million lb) in 1970. This was followed by a short term decline to less than
450,000 kg (1 million lb) in 1973. Catches for 1974 and 1975 were 910,000 kg
(2 million lb) and 1.55 million kg (3.4 million lb), respectively.

In the early years of the fishery, fishermen were limited to beam trawls with
a minimum mesh size of 2.9 cm (1% inches). In 1958 the minimum mesh size
was increased to 3.8 cm (1/2 inches) stretch measured inside the knots, and in
1975 the minimum mesh size was reduced to 3.5 cm (1% inches). Otter trawls
have been legal since 1962.

These mesh size regulations had been imposed to reduce fishing mortality on
small shrimp. Shrimp dealers were usually reluctant to buy small shrimp because
of low yield. As a result, small shrimp were discarded. In addition, ocean shrimp
are protandric (hermaphroditic) i.e., most individuals function first as males,
then as females. About 33 to 50% of the 1 -year-old shrimp develop into females
without first functioning as males (Geibel and Heimann 1976). Therefore a
minimum legal mesh size which permits escapement of most 1 -year-old shrimp
would insure an adequate spawning stock.

While the California Department of Fish and Game has maintained mesh size
regulations from the inception of the fishery, the Oregon Fish and Wildlife
Commission has not had shrimp mesh size restrictions since 1970. This action,

' Accepted for publication April 1977

^ Present address: National Marine Fisheries Service, Southwest Fisheries Center, La Jolla, CA. 92037.

OCEAN SHRIMP MESH EXPERIMENT

281

Area A

Area B-1

Area B-2

Area C

O Pt. Conception

Shrimp Beds

To Mexican Border

FIGURE 1. Fishing areas for ocean shrimp for California (courtesy of Dahlstrom).

and the sharp decline in landings in 1 973, have made re-examination of the effect
of mesh sizes on shrimp escapement necessary.

Department marine biologists conducted experiments with nets of different
mesh sizes aboard the research vessel N.B. Scof/e/dirom 26 April to 4 June 1956
(cruise 56-B-l ) to compare shrimp escapement through different sizes of mesh.
No definitive conclusions had been drawn from these experiments. The purpose

282

CALIFORNIA FISH AND GAME

of this paper is to report on my examination of the data from the 1956 shrimp
cruise. I conducted a more thorough analysis so as to utilize the information
efficiently and to obtain meaningful comparisons of the shrimp escapements
between the larger meshes and a control net with mesh size of 1.8 cm (0.69
inches).

1956 SHRIMP CRUISE
A 6-m (20-ft) beam trawl with a single cross bar was used during the 1956
cruise. For most of the mesh size comparisons, two trawl nets each 3 m (10 ft)
across at the mouth were hung side by side and fished for about 30 min. This
method should have eliminated bias created by the tendency of the shrimp to
school by size even within the same bed. Scouting began off Point Reyes and
continued northward until commercial quantities of shrimp were encountered
just south of the mouth of the Russian River in 73 m (40 fm ) . Once shrimp had
been located, a total of 100 trawls was made using nets with six different mesh
sizes (0.69-control, 1.43, 1.60, 1.62, 1.66, and 1.84 inches). These mesh sizes
were stretch measurements between knots (Table 1). Biologists took length
frequency samples from 65 trawls in which sufficient quantities of shrimp oc-
curred. Each sample consisted of approximately 100 length measurements of
shrimp caught by the test net and an equal number of lengths from the control
net. In the original analysis, length frequency samples from each net were
combined and compared with the corresponding combined samples from the
control nets (Figure 2). No further analyses were made on shrimp catch ratios
from test nets.

TABLE 1. Mesh Size and Thread Measurements of the Tested Nets and Control Nets

Used in 1956 Shrimp Survey

Manufacturer

measurements

(inches)

Measurements

after shrinkage

(inches)

Thread

0.75
1.50
1.75
1.88
2.00
2.25

0.69
1.43
1.60
1.62
1.66
1.84

12
12
27
36
36
36

OCEAN SHRIMP MESH EXPERIMENT

283

Number of Tows B
Net56B5 W^ 1 60'
Net 791 y/y 0.B9'

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Carapace Length (mm)

NOTE : ail bars begin at 0°/o

284

CALIFORNIA FISH AND CAME

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Carapace Length (mm)

NOTE : all bars begin at 0°/o

FIGURE 2. 1956 shrimp experiment length relative frequencies (LRF).

REVISION OF THE SAMPLING SCHEME
The original sampling scheme required a sample of 100 shrimp (or all shrimp
if less than 100 had been caught) from each net for each tow regardless of the
actual catch. A length relative frequency ( LRF ) was then constructed ( Figure 2 ) .
The LRF's showed the difference in shrimp length distributions between test net
and control net. However, it was impossible to estimate the percentage of
shrimp of a particular length or year class that had escaped without information
on the actual total catches of each tow. In order to do so, one needed first to
estimate the catch ratio yij for the mesh size i, i = 1, 2, 3, 4, 5 and shrimp length
j, j = 11, 12, . . . . , 25. yij is defined in term of the catches as:

7ii =

Mc-Pcj

T,.P,

Tc.Pc,

= q. 6ii

(1)

where yi, is the ratio of the mean catch per tow of shrimp of length j by the
test net i to that of control net c,
is the expected catch per tow of shrimp of length j by the test net

is the expected catch per tow of shrimp of length j by the control

net c towed side by side with the test net i,

is the expected total catch by the net i during the survey, i.e.

Ti- = mijLLi- where m tows are made during the survey,

is the expected percentage of shrimp caught by the net i that are of

length j

M-ii

T-
Pi,

111

and 9„ =

OCEAN SHRIMP MESH EXPERIMENT 285

The total catch (T;-'s) and percentage of certain shrimp size (Pij) of equation
(1) are estimated as follows:
Ti- is estimated by
nii

K. = S N„k, (2)

k= 1

and jUi- is estimated by

N, •

M. •

where Nki,) is the k"' catch for the net i, to be distinctive from N;y, the number
of shrimp of k*'' length and i'^ net in equation 3.
Ni- is the total catch by the net i.
P,i can be estimated by the proportion of shrimp of length j from the total catch
by the net i, Nii/N;-. It follows that T;- • Pij can be estimated by Nij, T^- Pcj by
Ncj and y,-^ from equation (1 ) by

7.J

N,.

Nc.

(3)

where Nij is the total number of shrimp of length j caught by test net i and
Ncj is the total number of shrimp of length j caught by the control net c.

Since it was difficult to measure all shrimp in the catch, although it had been
done in flatfish and roundfish experiments (Davis 1934; Best 1961), a sample
was taken from each tow. The sample proportion (Pij) calculated from the
pooled sample can be used to estimate Pij:

P„ = ^ (4)

where n, is the number of shrimp in the pooled sample from net i and ni,
is the number of shrimp of length j in the pooled sample from net i.
Assuming that for a sample of size n, the nurnber of all sizes (n;,) follows a
multinomiial distribution with parameters n,, Pij., ' ?■■ = 1, then the sample pro-
portion Pij is the maximum likelihood estimators (MLE) of Pij. With the total
catch of net i ( N,- ) and net c ( N^- ) and the sample proportion ( Pi,, Pcj ) , we obtain
the MLE of y,, through yi* as

N,. P„ ..

286 CALIFORNIA FISH AND CAME

where a = J21

I-

and e„ = i

-'■J

Pc,

This follows that if 0,, • • • , 9^ are MLE of 0^ , • • • , 0 „^

and W( 0 1 , • • • , 0„,) is a single valued function of 0,, • • / , 9 ^, then
W( e,, • • • , 0 ^) is the MLE of W( 0,, • • • , 0 J.
The sample catch ratio y^ can be used to estimate y-:^,
where

n,j n, P„ n, P,, _ n,^
ricj ricPcj n, Hcj n.

In order for this estimate to be the MLE of yij, equations (5) and (6) must be
equal. This leads to the relation

^ * n, ■»

and implies that njn^ must be equal to q,
where

n, N,.

^ i\. Nc.

This means the ratio of sample sizes for the test net i and the control net c must
be proportional to that of the total catches N- and N,- or q;. When N;- and
Nc- are not known, then N;- and N,- are to be estimated by the sample statistics.
The sample sizes derived from equation (7) are like those from a proportional
sampling scheme and will make yi, in the maximum likelihood estimator of 7,1,
a preferred statistic in most inference problems. From equation (7), the
original sampling scheme would be correct if the catches were similar for all
nets. However, I know this was not true, especially for the larger meshes. More
small shrimp escaped from the larger mesh and thus the total number of shrimp
for each tow decreased (Walter Dahlstrom, Dept. Fish and Game, pers. com-
mun.). Therefore some adjustments need to be made in order to obtain MLE of

7ii-

From the 1956 shrimp data, the catch ratio of a test net and the control net
could be calculated according to equation ( 5 ) . Pij's and P,|'s were obtained from
combined length frequencies from all samples except those with no matches
(Table 2). Total numbers of shrimp caught (N,- and N,-) were estimated as

OCEAN SHRIMP MESH EXPERIMENT 287

follows. The original data consisted only of the weight for each tow; count per
pound was not recorded for every tow. I needed to estimate the total number
of shrimp caught for each tow and sum them to obtain the total catch for any
particular net. In order to estimate the total number of shrimp caught for each
tow, I obtained the median length of shrimp from the existing sample. Its weight
was estimated from a May 1968, Bodega Bay shrimp length-weight curve.

W = 9.34497 • 10"' L^^sn (8)

where

W was the predicted weight (g)
and

L was the shrimp carapace length (mm).

It was suggested (Pienaar and Ricker 1968) that when a sample length fre-
quency is close to a normal distribution, the sample mean weight can be predict-
ed by using sample mean length and the length-weight curve equation (8) . The
bias of the estimator is proportional to sample variance. This conversion is
normally done for each age group separately. Because of the large amount of
data collected in the 1956 survey, a simplified scheme was adopted to estimate
the sample mean weight by using the sample median length. Let m be denoted
the sample median length, w^ as the corresponding estimator for the sample
mean weight through the W-L equation, and w as the true sample mean weight,
then the bias of w„ is defined as

where ja«^ is the population average of w^

and ja^ is the population average of w.

Both 1956 data and 1973 market sampling data from Area B-2 were used to

estimate y3 where sample mean weights or count per pound were available.

w^ and w were calculated for each sample:

Let

_ Wi, i = 1, • • • , n.

Vi ==

w„

then

V =

Iv,

is an unbiased estimator of j3.

The 1956 data had 17 samples where counts per pound were recorded (n =
17), we obtained v = —0.06 and s-^ = 0.11. Because of the large standard
error of v, the bias was not significantly different from zero. There were 48
samples from area B-2 in 1973 which were used for checking the bias (n = 48)
which was v= 0.24 with s— = 0.06. This indicated that sample median length
through 1968 W-L curves overestimated the sample mean weight. This could
have resulted from the skewness of the length frequency to the left so that the
sample median length was larger than the average sample mean length. The
skewness could be caused by the escapement of small shrimp. Since only the
catch ratio was of interest, the bias of w^ may not have had any significant effect
on the results. Thus Wn, will be used later to estimate the count per pound of each
tow.

Now for the k"' tow of the i'*' net, let w,k be the actual catch (in pounds) and
Zik be the estimated count per pound where k ^= 1, • • • , m,, and m, is the total
number of tows made for the i**" net; and let N^,) be the approximated number

288 CALIFORNIA FISH AND GAME

of shrimp caught for the k'*" tow and i'*' net, then the total number of shrimp
caught for the i'^ net is

m, ^ m,

N,. = V N,„, = V W„Z., (9)

k = 1 k - 1

As to the control net, the total number of shrimp caught corresponding to the
i"' net is

m, rrii

Nc. = :i; Nc,M = i; w.kZck (10)

k = 1 k = 1

Using equations (9) and (10) we have

'xy

N,.

■ a.

k -

N„k)
1

q -

Nc(k)

k =

(II)

where q„ Niz and N,- are the estimators of qi, N;- and N,- of equation (5).

The resulting q/s for the five larger net mesh sizes 1.43, 1.60, 1.62, 1.66 and
1.84 inches were 0.6, 0.16, 0.12, 0.065, and 0.035, respectively. Sample length
frequencies and the q/s (Table 2) enabled me to estimate y;, according to
equation (5).

RESULTS

The ultimate objective of this analysis was to determine differences in shrimp
escapement from a series of trawls with varying mesh sizes. The catch ratio for
each carapace length from 11 to 24 mm (4 to 1 1 inches) for the larger nets was
calculated according to equation (5) (Table 3). The escapement rate of any net
for a particular shrimp length is 1 - y,-^.

If the differences of the catch ratios among the nets were only due to selectiv-
ity, then a symmetrical ogive with a lower asymptote of zero and an upper limit
of unity would be expected. But the survey data (Table 3) showed that in some
of the catch ratio comparisons there were ratios reaching a level greater than
unity. As was pointed out in Beverton and Holt (1957), this could have been
due to either sampling error or the differences of fishing efficiencies. I believe
that a real difference in efficiency did exist because some of the commercial
catch data indicated that larger mesh nets had higher total catch in weight than
did smaller nets.

The relationship of the catch ratio and the shrimp carapace length for each
of the nets was fit using a probit analysis technique since the scatter diagram
showed that the data approximated a normal sigmoid curve. Probit analysis is
the analysis of quantal response data using the probit transformation. It is used
commonly in bio-assay experiments where different dosages of toxic substances
are tested for the mortality rate which they produce (Sokal and Rohlf 1969). In
the case of mesh experiments, the catch ratio is an index of the fishing mortality

OCEAN SHRIMP MESH EXPERIMENT

289

c
o
u

•a

»->.'

■^
^

-C

■o
c

>■
u
c
if

c
-J

o o o ^ »—

O »— LT) LH O^

rs) ^D CO Ln

O O O rs4 r-

O^ »— G^ O (^

Ln m '^ rsi

»— rN »—

O »— (~^ <— '-'^

O^ -^ oO ro
rn O ro O^

O O O '^

rs CO LO LO LO

ro ro rsj ro

»— rs »—

ro .^ O O »—
^— Tt OO ^D

'^ 'sO O^ ^ LO

Tj- LA »— 0^
1— rs

1— 0^ O CO (^
CO ro ^

^ .— — ro •—
in v£ O •—

r^ O

1 — r^ro»-orn ^'^' —

O LH ro ro -^
rs CO O O

t^ r— ro r^ O

rvj rsi LA m tn

<— rsi .—

^ O^ >— oo >—
^ ^D O I^

,— ^ 1\ u-i 1-^

rvi o ("^ LA vD

rA "sD O^ CO <~o

. — LD O LA 1

tvi CM r—

r-^ O CO rN

O >— LA rsi

PA 1- ■—

r^ 1^ —

Sr^i CO
rvj t —

rsi rsi 1 —

r^ 0> 0% rA »—
r-v lA >—

LA f-^

LA ro O

^D •— O

I— r^ I—

1 — -vD LA

•* O

LA ^

rA CO

llJD ("A ^

Oi CO O
LA PA *—

o^ o CO r^ •—

A-J rA O LA O
.— rA r^ >—

CM O <-M (~M CO

PA »— CT^ O^ (A

CO CO O fA rsi
r^ LA tt

g;^ °

rr ^ o

TOO
O

rsi O
O >—

CO ■—
O

1 — rsi rA Tf LA

CO a^ o
>— T— rvi

1 — rsi rA T LA
CM (VI r-i rsi (VI

to-

290 CALIFORNIA FISH AND CAME

TABLE 3. Catch ratio y,,.

Carapace Mesh size (inches)

length (mm) 1.43 1.60 1.62 1.66 1.84

n 24 0 0 0 0

12 16 0 0 0 0

13 12 0 0 0 0

14 16 0 0 0 0

15 30 .02 .01 0 0

16 32 .06 .01 0 0

17 56 .10 .03 .01 .01

18 76 .21 .04 .02 .01

19 1.32 .31 .10 .05 .02

20 1.25 .41 .16 .14 .08

21 1.69 .58 .43 .25 11

22 1.35 .69 .67 .61 15

23 1.41 .82 .96 .65 .28

24 - .32 .90 1.53 .27

rate which increases with the length of the fish. Thus it seems suitable to apply
probit analysis to estimate the catch ratio of any size of the shrimp when a
particular mesh size is used (Table 4, Figure 3). For any given x, the correspond-
ing probit value y will enable us to calculate the probability of Y less than y; P(Y
< y ) . This probability is then used as the predicted catch ratio for that carapace
length X ( Figure 4 ) . The estimation of the catch ratio of any carapace length for
any one of five nets is illustrated as follows. For the 1.43-inch net the expected
catch ratio for the shrimp of length 17.4 mm (0.6 inches) (this includes the
shrimp size x; 17.0 <x< 17.8) is 0.56:

y ,7^= -0.7426 + 0.3404 (17.4) =5.18
pjY < 5.181 Y ^ N(5,1)j=0.56

TABLE 4. Probit Regression Lines and the 50% Selection Length of Five Mesh Sizes.

Mesh size Probit regression 50% selection

(inches) lines length (mm)

1.43 y = -0.7426 4- 0.3404x 16.87

1.60 y = -2.7186 + 0.37x 20.87

1.62 y = -5.8 + 0.498X 21.67

1.66 y = -6.055 -l- 0.491 79x 22.47

1.84 y - -3.8015 + 0.3517x 25.03

y = the probit value which is the normal deviate plus five
X = carapace length (mnn)

The 50% selection length is the x value corresponding to y equal to five (Table
4). A simple linear regression line was fit to the 50% selection length and the
corresponding mesh sizes (Figure 5). it was found to be

y = 21.38 + 19.93(x-1.63) (12)

where y : the 50% selection length (mm)

and X : the mesh size (inches).
The predicted 50% selection lengths for the mesh sizes 1 .37, 1 .43, 1 .50, and 1 .60

OCEAN SHRIMP MESH EXPERIMENT

291

8.0

7.0-

MESH SIZE

•

1 43"

1 60"

■

1 62"

1 66"

.1 84"

11.0

13.0

17.0 19.0

CARAPACE LENGTH (mm)

FIGURE 3. Probit regression lines for estimation of catch ratio.

inches are 16.20, 17.39, 18.79, and 20.78 mm (Table 5). With 50% selection
lengths for various mesh sizes and a length frequency of shrimp available to the
net, it is possible to estimate the percentage of the shrimp that is smaller than
50% selection length when a certain mesh size is used. The length frequency
of any age group can be fitted to a normal distribution. The length frequency of
1 -year-old shrimp in 1956 was compared with a normal distribution. Using
chi-square techniqtje, the difference detween the two distributions was not
significant at 5% level (Table 6). Thus for 1- or 2-year-olds the expected length
frequency can be calculated from the sample means and sample standard devia-
tions (x and s). This is illustrated by using 1968 Area B-2 data. The carapace
length of 1-year-olds averaged from 16 to 17.8 mm (0.6 to 0.7 inches) while the
mean length of 2-year-olds increased from 20.35 to 21 .64 mm (0.8 to 0.9 inches)
through the season. The standard deviations varied little (Table 7). The percent-
age of shrimp smaller than 50% selection length by a particular mesh size was
estimated for any age group using the normal approximation. For example, if
1.50-inch mesh was used, all the 1 -year-olds with x = 16 mm and s = 0.76 mm
would have a higher than 50% escapement rate. As the season progressed, 85%
of 1 -year-olds with x = 17.8 mm and s = 0.94 mm were smaller than 50%
selection length. Since 2-year-olds were much larger than 1 -year-olds during the
month of May, only 5% of 2-year-olds had more than a 50% escapement rate
(Table 8, Figures 6 and 7).

292

CALIFORNIA FISH AND CAME

I
u

0.00

13.0

15.0

17.0 19.0

CARAPACE LENGTH (mm)

21.0

23.0

25.0

FIGURE 4. Probit catch ratio estimated from probit regression.

TABLE 5. 50% Selection Lengths, St. Errors, and 95% C.L Derived from the Least Squares

Regression Line.

95% CI.

(mm)

16.2 ± 1.65

17.39 ± 1.36

18.79 ± 1.05

20.78 ± .75

Mesh size

50% selection

St. error

(inches)

length (mm)

(mm)

1.37

16.20

.59

1.43

17.39

.49

1.50

18.79

.38

1.60

20.78

.27

TABLE 6. 1956 April-June 1-year-old Length Frequency Fitted to Normal Distribution

Carapace Observed Expected (E-0) ^

length (mm) frequency frequency E

11 8 5.51 1,125

12 84 71.63 2.136

13 294 286.52 0.195

14 439 440.8 0.007

15 230 242.44 0.63

16 47 55.1 1.19

TOTAL 1102 1102 5.28<x'=7.81

Because of the short life span of California ocean shrimp, the high natural
mortality rate of 1 -year-olds, and the wastage during processing (Dahlstrom
1972), it seems reasonable to protect the 1 -year-olds so that the fishery can be
carried on during the next season. Before any definite spawning ecruitment
relationship is found, one criterion of regulating the mesh size woi d be based
upon the escapement rate for the 1 -year-olds. What I suggest is an average

OCEAN SHRIMP MESH EXPERIMENT

293

E
E

_1
LU

o
o
O
ID

Y = 21.38-f(X-1.63) • 19.93

0.5

1.0 1.5 2.0

MESH SIZE (INCHES)

2.5

FIGURE 5. Linear relationship of 50% selection length and mesh sizes.

TABLE 7. AER's for 1968 and 1974 Area B-2 Shrimp Samples.

Year
1968.

1974.

Carapace

AER

wth

Age

length (mm)

(inches)

1.43

1.60

162

16.

0.76

0,68

0.96

0,99

17.1

0.81

0,53

0.91

0,98

17.83

0.94

0,34

0.85

0,96

20.4

0.96

-0,3

0.59

0,79

21.2

0.92

-0,43

0.48

0.65

21.6

0.88

^,51

0.43

0,57

14.32

0,99

0,81

0.99

0,99

18.04

0,94

0,28

0.83

0,96

17.04

1,3

0.48

0.89

0.97

19.76

1,16

-0.18

0.65

0.84

21.11

0,53

-0.42

0.49

0,67

21.65

0,53

-0,53

0.42

0,54

Mesh sue (i

nchesj

1.37

1.43

1.50

1.60

0.60

0.96

1.00

0.05

0.68

0.16

0.69

0.99

1.0

0.33

0.05

0.32

0.85

1.00

0.17

294 CALIFORNIA FISH AND CAME

TABLE 8. Percentage of Shrimp with Escapement Rates of More Than 50% for 1968 Area

B-2 Data.

Age
Month (years)

May 1

2
July 1

2
Sept 1

escapement rate (AER) for one age group for various mesh sizes. Since the
growth rate of shrimp varies among seasons and among locations, the AER's of
various mesh sizes can be used to determine the effect of those mesh sizes on
the fishery if the length relative frequency (LRF) of any age group is known.
The AER is defined as,

Sry = Sh,i,(1 -7,i) (13)

j
where S,-y is the AER for age k when mesh size i is used

h,jk is the LRF by a control net of the length j of age k
XK\v = 1,

j
and the subscript j is summed over the carapace length of age k. Thus, S; • ^ is

the weighted average escapement rates for age k where the weights are the

LRF's.

The derivation of equation (13) is as follows:

I have the average catch ratio for age k by mesh i as

Ml-

2 P,jk
j

1 Pcjk

7,.k = rr-z— (14)

Applying the relationship given in equation ( 1 ) to equation (14) and assuming
7ij is the same for all age groups, i.e. yij = yijk, I have

7>-k

S Pcjk
j

7>j

SPcjk
j

= S hcjk

7.J

(15)

where h^k

cjk

i Pcjk
j

S hcjk
j

OCEAN SHRIMP MESH EXPERIMENT

295

ONE YEAR OLD 1968

1.37 1.50

month 5
x = 16.0077
s= 0.7683

month 7
X =17.0559
s= 0.8117

carapace length (mm)

FIGURE 6. LRF of 1968 1 -year-old approximated by normal distribution and 50% selection length
for four mesh sizes.

296

CALIFORNIA FISH AND GAME
TWO YEAR OLD 1968

month 5
X =20. 3571
5= 0.9588

month 7
X =21.2058
5= 0.9167

month 9
X =21.6429
s = 0.8844

11.0 14.0 17.0 20.0 23.0 26.0

carapace length (mm)

FIGURE 7. LRF of 1968 2-year-olds approximated by normal distribution and 50% selection length
for four mesh sizes.

Mesh size (inches)

1.50

1.55

0.19

0.91 ± 0.15

1.08 ± 0.14

0.17

0.80 ±0.12

0.97 ±0.12

0.16

0.69 ±0.10

0.86 ± 0.09

0.15

0.58 ± 0.08

0.75 ± 0.06

0.15

0.47 ± 0.07

0.64 ± 0.06

0.15

0.36 ± 0.07

0.53 ± 0.06

0.15

0.25 ± 0.07

0.42 ± 0.06

0.15

0.14 ± 0.09

0.32 ± 0.08

OCEAN SHRIMP MESH EXPERIMENT 297

and the subscript j is again summed over the age k.

Si . I, = 1 — 7; • k, thus equation (13) is obtained. AER is determined by y^^ and
hcij. Yii's are given in Table 3 and h.^/s are approximated by a normal distribution.
In order to estimate the AER's for the various mesh sizes, 1 968 and 1 974 Bodega
Bay shrimp data were used to provide 12 age groups v^ith distinctive LRF's. The
AER's for the meshes 1.43, 1.60, and 1.62 inches are calculated for each of the
12 age groups (Table 7).

TABLE 9. AER's with 95% Confidence Intervals

Length (mm) 1.37

14 0.44 ±

15 - 0.33 ±

16 0.23 ±

17 0.12 ±

18 0.01 ±

19 -0.10 ±

20 -0.21 ±

21 -0.21 ±

AER is the function of the mesh size and LRF which is generated by x and s
(Table 7) . Table 7 was constructed under the assumption that yij is independent
of the age, time, and location. Therefore, for two different age groups with x and
s, the AER's are the same, whereas for two groups of the same age yet different
X, and (or) s, the AER will be different.

The current issue with respect to the shrimp fishery is whether or not 1.50
inches is the proper legal mesh size. The best way to answer this question would
be to conduct experiments where a control net is towed side by side with
commercial nets of differing mesh sizes (1.30 to 1.60 inches) so that the escape-
ment rates of 1.50-inch net can be directly estimated from the catch data.
Lacking this, data in Table 7 were used to derive estimated AER's for nets with
mesh sizes not included in the 1956 experiments. A multiple regression line was
fitted to the data where the AER's are regressed upon the mesh size, mean
length, and standard deviation. The backward stepwise multiple regression line
includes both mesh size and mean length, but not the standard deviation. The
fitted line is

y = -2.89 + 3.55 x, - 0.11 X2 (16)

where y : AER

X, : mesh size

X2 : mean length of an age group
and the multiple correlation coefficient squared (R^) is 0.83.

Equation (16) then is used to estimate the AER of nets 1.37, 1.50, and 1.55
inches for any age group of certain average length. For example, if mesh size
1.50 inches (x,) is used and the mean length of shrimp of 1-year-olds is 16 mm
(X2), the estimated AER (y) is 0.69 with '95% C.I. (0.59,0.79). Table 9 gives the
estimated AER for the three nets applied to average lengths ranging from 14 to
21 mm (0.6 to 0.8 inches).

In order to find the effects of net 1.50 or 1.37 inches on California ocean
shrimp, it is necessary to know the average carapace length of 1- and 2-year-olds

298 CALIFORNIA FISH AND CAME

through the season. Since Area A has the largest shrimp bed, I used data from
this area. For the 1 -year-olds, the median average carapace length increased
from 12.8 to 16.3 mm (0.5 to 0.6 inches) through the season (1969-1974)
(Nelson and Dahlstrom 1975). The median carapace length was taken for each
month across the years. Based on the median carapace length, nets with a mesh
size of 1.37 inches will, on the average, catch 65% of the 1 -year-olds in May
and catch ll^/o of the 1 -year-olds in September. A 1 .50-inch mesh net will catch
16% of 1 -year-olds in May and 31% of 1 -year-olds in September. A 1.55-inch
mesh size will catch at most 6% of 1 -year-olds in May and 14% of 1 -year-olds
in September. But the 2-year-olds (18.7 to 21.0 mm) will have a 65% AER in
May and 32% in September. This large AER for 2-year-olds is a loss to the fishery
and should be prevented (Tables 9 and 10).

TABLE 10. Median Length of 1- and 2-Year-Old Shrimp in the Eureka

Area, 1969-1974.

Age (years)
Month 1 2

April 12.8 18.7

May '. 14.47 20.

June 14.53 20.

)uly 15.25 20.5

August 15.76 20.8

September 16.33 21.

October 16.3 21.6

As far as AER's are concerned, 1.50-inch mesh seems to be a reasonable
choice. It insures good escapement of 1 -year-olds through the season and at the
same time will allow harvest of most of the 2-year-olds (Table 9) . Commercial
fishermen often argue that large mesh nets cause the efficiency to decrease as
the mesh size increases. Therefore, the efficiency of various mesh sizes should
be taken into consideration when making the final decision as to an appropriate
minimum mesh size for the shrimp fishery.

Catch per hour (CPH) has been used as an index of fishing efficiency. But
the difficulty of making inferences directly from commercial catch data is that
fishing time, boat size, fisherman's know-how, and the location of fish are all
variables. Thus, the differences in CPH can be due to either the mesh sizes
and (or) the other variables. Since there have been no experiments conducted
to check the CPH of nets with different mesh sizes as the only variable, we chose
the CPH of four otter trawls with different mesh sizes fished by Bodega Bay
vessels from June through August 1975. In this case fisherman's know-how and
boat size were the variables. Time and location were the same since all four
boats fished during the same 3 months and the Bodega Bay shrimp bed (Area
B-2) is rather small and distribution of shrimp is fairly uniform (Walter Dahl-
strom, pers. commun.). Because larger mesh nets tend to have longer
headropes, the CPH is further divided by the length of headrope. Thus the
statistics used are CPH per foot (CHF). Since there is more homogeneity of
fishing conditions within a given day than b^'tween days and the lack of knowl-
edge of the underlying distribution of CHF, a nonparametric multiple compari-
son was used in analyzing the data (Bradley 1968) (Table 11).

OCEAN SHRIMP MESH EXPERIMENT 299

TABLE 11. CHF's of Four Mesh Sizes Used in Bodega Bay, 1975.

Fishing. Mesh size (inches)

Month day 1.44 1.50 1.51 1.54

June 1 47.83 66.46

2 27,77 22.77 34.93 59.40

3 15.85 27.64 26.72 47.74

4 26.86 - 24.91 42.18

5 42.11 37.52 37.41 40.44

6 22.26 17.16 18.60 22.38

7 5.41 2.26 8.75 9.26

8 - - 24.62 28.40

9 39.61 33.89 28.22 42.06
10 44.44 27.09 39.07 31.51

July 1 53.65 42.72 71.10 76.86

2 22.95 13.03 77.28 126.61

3 - - 105.36 115.40

4 83.03 71.35 70.71 63.97

5 11.73 7.96 8.10 19.59

6 22.47 24.77 24.32 40.00
August 1 25.79 34.72

2 19.65 22.40 26.18 30.11

3 - - 9.92 16.47

4 16.37 17.40 16.25 15.86

5 - - 0 -

6 - - 0 -

7 0.47 0 0-

8 46.02 _ _ _

9 66.50 74.57 - 188.43

10 48.63 37.34 - 43,67

11 26.00 50.11 - 63.75

12 30.25 46.18 - 50.76

The data in Table 1 1 are further condensed by taking the average of the entries

within each fishing day across the months (Bradley 1968) (Table 12).

TABLE 12. Mean CHF's of Four Mesh Sizes Used in Bodega Bay, 1975.

Fishing Mesh sizes (inches)

day 1.44 1.50 1.51 1.54

1 39.72 38.72 59.47 71.66

2 .' 23.46 19.40 46.13 72.07

3 15.85 27.64 47.33 59.87

4 42.09 44.38 37.29 40.67

5 26.92 22.74 15.17 30.02

6 22.37 20.97 14.31 31.19

7 2.94 1.13 4,38 9.26

8 46.02 - 24.62 28.40

9 52.84 54.23 38.22 115.25

10 46.54 32.22 39.07 37.59

11 26,00 50.11 - 63.75

12 30.25 46.18 - 50,76

For the final analysis, data for fishing days 8, 11 and 12 were eliminated

300 - CALIFORNIA FISH AND CAME

because of incomplete entries. The CHF's within each fishing day were ranked
(Table 13) and the Friedman test (Bradley 1968) was applied. I then have

12 ^. '", m(c+l).

mc(c+ 1) i = 1

c^R,. — -^^r

C 111

1 (1 R„r - 3m(c+l)

mc(c+ 1) i = 1 J _ 1
12

9 • 4 • 5

= 8.87

2158 - 3 • 9 • 5

where R,; is the entry in j'Vow and the i'^ column

m : number of fishing days

c : number of mesh sizes.
X^, under H,, of no different CHF's among the four nets, follows X^ distribution
with (c-1 ) degrees of freedom.

TABLE 13. Ranks of the Four Mesh Sizes Used in Bodega Bay, 1975.

F/sh/ng Mesh sizes (inches)

day 1.44 1.50 1.51 1.54

1 2 13 4

2 2 13 4

3 12 3 4

4 3 4 12

5 3 2 14

6 3 2 14

7 2 13 4

8 2 3 14

9 A A J. Ji

TOTAL 22 17 19 32

Since X^, = 8.87 > X^j = 7.81, I concluded that there is a difference of CHF's
among the mesh sizes. From Table 12, it is apparent that the 1.54 inch mesh net
ranks consistently higher than the other three meshes. This indicates that the
larger mesh net will not result necessarily in decreased fishing efficiency. If the
fisherman is competent, and the net is handled correctly, mesh size, within
limits, may not have a major effect on the fishing efficiency. In addition, there
does not seem to have been significant CHF differences among the three small
nets in my analysis. The possibility of decreasing efficiency as the mesh size
increases seems to be questionable within the range of mesh sizes with which
I dealt.

DISCUSSION

The beam trawl net with 1 .50-inch mesh size would allow an escapement rate
for 1 -year-olds of 91% in April to 58% in September (Table 9). Since the original

OCEAN SHRIMP MESH EXPERIMENT 301

survey in 1956, the shrimp fleet has changed from beam trawls to otter trawls.
The difference between the escapement rates of these two kinds of nets is
probably slight (Davis 1934).

I recommend that experiments be conducted to determine the escapement
rates of the otter trawls. Thus, the results of 1956 experiments can be directly
or indirectly applied to the otter trawls used in the present shrimp fishery.

The 1975 data from Bodega Bay comparing the four commercial otter trawl
mesh sizes indicate that the small meshes do not have necessarily higher catch
per effort than large mesh nets. On the contrary, the largest net (1.54 inches)
had the highest CHF for several seasons. This high catch can be due to a
combination of factors; large and powerful vessel, competence of the fishermen,
net construction, and mesh size. The estimated escapement rates of the 1 .50 inch
mesh net and the comparison of fishing efficiency lead me to support the
adoption of 1.50 inches as the legal minimum mesh size.

ACKNOWLEDGMENTS

The author wishes to thank her colleagues at the Department of Fish and
Came for reviewing the manuscript and providing editorial assistance.

REFERENCES

Best, E. A. 1961. Savings gear studies on Pacific Coast flatfish. Pac. Mar. Fish. Comm., Bull., 5 : 25-48.
Beverton, R. ]. H , and S. ). Holt. 1957. On the dynamics of exploited fish populations. Fish. Inves. Ser, 2, 19 : 533.
Bradley, J. V. 1968. Distribution-free statistical test. Prentice-FHall, Inc., Englewood Cliffs, New Jersey.
Dahlstrom, W. A. 1972. Status of the California ocean shrimp resources and its management. Mar. Fish. Rev.,

35(3-4) : 55-59.
Davis, F. M. 1934. Mesh experiments with trawls, 1928-1933. Fish. Inves. Ser. 2, 14(1) : 1-36.
Celbel, John)., and Richard F. G. Heimann. 1976. Assessment of ocean shrimp management in California resulting

from widely fluctuating recruitment. Calif. Fish Came, 62(4) : 255-273.
Nelson, Nancy E., and Walter A. Dahlstrom. 1975. Ocean shrimp report for the 1974 season. Calif. Dept. Fish and

Came, Mar. Resour. Admin. Rep., (75-3) : 1-18.
Pienarr, L. V., and W. E. Ricker. 1968. Estimating mean weight from length statistics. Canada, Fish. Res. Bd., J.,

25(12) : 2743-2747.
Sokal, R. R., and F. ). Rohlf. 1969. Biometry — the principles and practice of statistics in biological research, W. H.

Freeman and Company, 776 p.

302 CALIFORNIA FISH AND CAME

MIGRATION OF AMERICAN COOTS
WINTERING IN NORTHWESTERN CALIFORNIA

American coots (Fulica americana) in northwestern California are common
winter visitants and migrants and uncommon in the summer months. A few
broods have been recorded from Del Norte County and Humboldt County
(Yocom and Harris 1975).

In the spring of 1954, 209 American coots were banded in the area of Areata,
California, known as the Areata "Bottoms." The purpose of the banding was to
find out where the birds migrated once they left the wintering areas along the
coast and along what routes of migration they traveled. Recoveries from hunters
were the source of most of our data on the banded birds. The banding was done
under the supervision of C. F. Yocom. Twenty-three of these 209 coots were
recovered during the fall-winter 1954-55 waterfowl hunting season either as a
result of hunting, trapping, or other mortality factors. All of these 23 coots were
recovered within 900 m (1000 yards) of the banding site. This seems to be
significant in that these coots apparently returned from their northern breeding
grounds to the exact area that they had occupied the preceding winter.

From banding recoveries, it is evident that some of the wintering American
coots from the Lake Earl area, Del Norte County, south to the Eel River, Hum-
boldt County, in northwestern California, breed as far away as the marshes of
British Columbia and on across the Rocky Mountains to at least the prairie
potholes of Alberta, Canada (Figure 1 ).

The recovery records of American coots banded in northwestern California
were similar to many recoveries of wigeons {Anas americana) , and mallards
{Anas platyrhynchos ) that had been banded in Humboldt County and recov-
ered in Oregon, Washington, and British Columbia (Yocom and Denson 1962).

California Department of Fish and Game recovery records of coots banded
at Tule Lake, Siskiyou County, California, prior to the waterfowl hunting season,
and recovered during the hunting season in Humboldt and Del Norte counties
indicate that there are coots that migrate in an east-west direction across north-
ern California. The route would be from Tule Lake across the Cascade, Klamath
and North Coast ranges to the northwestern California coastal areas. Also, coots
banded in winter in California at Gray Lodge, Sutter County, and Grizzly Island,
Solano County, have been shot in the northwestern coastal areas of California
(Figure 2).

Apparently, mountains are no barrier for migrating American coots.

Migrations of coots have not been recorded because they move at night;
however, we have some information that may represent typical activity of coots
as they start migratory flights. William Henry, graduate student in Wildlife Man-
agement at Humboldt State University, observed what he considered the start
of northward migration on April 1 8, 1 976, at 7:55 p.m. Henry's observations were
made at the South Spit of Humboldt Bay, Humboldt County, California. He
stated the following: "Large concentrations, 300-400 coots in close proximity to
each other and exhibiting what appeared to be nervous behavior, gathered along
the sandspits. Single coots took flight and headed into the wind, which was out

NOTES

303

BANDED IN HUMBOLDT
COUNTY AND RETURNED
FROM ELSEWHERE

BANDED ELSEWHERE AND
RECOVERED IN HUMBOLDT
OR DEL NORTE COUNTIES
(a-Humboldt Co., b-Del Norte
Co., c-Arcata)

Figure 1. Recovery locations of American coots banded near Areata, Humboldt County, Califor-
nia, or banded elsewhere and recovered in Humboldt or Del Norte counties, northv^est
California.

of the northwest at a velocity of 10-25 miles (16-40 km) per hour. The birds
rose to about 150 feet (50 m) in height and turned to the northeast still gaining
altitude. Many coots circled to higher altitudes before heading off to the
northeast." He noted that the coots flew off as scattered single birds rather than
in flocks.

304

CALIFORNIA FISH AND GAME

(/• IDEL NORTE

LAKE

70 mi

SCALE 113km

• RECOVERY SITE
A BANDING SITE

Figure 2. American coots recovered in FHumboldt and Del Norte counties, northwest California,
that were banded at either Tule Lake, Siskiyou County, Gray Lodge, Sutter County, or
Grizzly Island, Solano County, California.

On February 20, 1977, at about sundown and with the fog moving in, Yocom
noted eight tight groups of American coots in the water near the U.S. [Highway
101 area of Freshwater Lagoon, Humboldt County. There were about 100 birds
in each compact group, and individuals were moving about quickly in what
appeared to be a nervous manner. This action may have preceded northward
migration that may have occurred later that evening or night.

NOTES 305

ACKNOWLEDGMENTS

We wish to thank Frank Kozlik and Warren Rienecker, California Department
of Fish and Came, for sending banding recoveries of coots from northwestern
California, and Fred Kindel and Dale Horn, former Wildlife students at Humboldt
State University, for banding American coots on the Areata Bottoms.

REFERENCES

Yocom, C.F., and E.P. Denson, |r. 1962. Importance of northwest coastal California to waterfowl. Calif. Fish Game,

48 ( 1 ) : 65-76.
Yocom, C.r., and S.W. Harris. 1975. Status, habitats and distribution of birds of northwestern California. Humboldt

State University Bookstore. Areata, California. 74 pp.

— Charles F. Yocom, R. J. Bogiatto, and j. C. Eshelman. Department of Wildlife
Management, hlumboldt State University. Accepted for publication June 1978.

A DIVER-OPERATED NET FOR CATCHING LARGE NUM-
BERS OF JUVENILE MARINE FISHES

As an integral part of the Department of Fish and Came's ongoing research
into central California marine sportfish, we investigated various aspects of the
population biology of juvenile fishes associated with kelp, Macrocystis s[i, and
the kelp canopy. During most months many juvenile fishes can be found closely
associated with kelp. However, prior attempts to collect these fishes with assort-
ed types of equipment were largely unsuccessful. A device capable of easily
capturing large numbers of juvenile fishes within the kelp forest, as well as
beneath the kelp canopy, was needed for our proposed mark and recapture
study. We felt that a non-gilling net operated by two scuba divers might work
satisfactorily.

Netting catalogues were consulted for information on available twine material,
mesh size and style, and net sizes. We selected a 3.7 by 3.7-m (12 by 12-ft)
"drop net" constructed with 18-lb test nylon. To avoid gilling fish and to create
less drag in the water, we chose 6-mm (%-inch) mesh, regular knit style.

The net was dyed using two packages of dark red Rit dye. After drying, four
38-mm (1.5-inch) diameter wooden dowels 1-m (39-inches) long were tied
along two sides of the net (Figure 1 ). These extensions enabled the divers to
open the net fully and maneuver it more easily.

We operated the net in a variety of ways, fitting the capture method to the
specific situation. Most frequently, the net was lifted beneath a school by divers
on opposite sides of the net ( Figure 1 ) . When a school of fish was located, the
net was deployed well below them, usually just above the bottom. The divers,
equipped with buoyancy compensators, partially inflated these devices and
began a rapid swimming ascent keeping the net open as far as possible. Thus,
the net was brought up around the fish. After the school was captured in the
bag of the net, the sides were brought together and rolled on the dowels to
prevent the fish from escaping.

Two important points need to be mentioned. First, the divers must be careful
to exhale while rapidly ascending to prevent an air embolism from occurring.

306

CALIFORNIA HSH AND GAME

FIGURE 1. Net with dowels attached. Photograph by Kim McOeneghan, November 1976.

Second, attention must be given to the path of rising scuba exhaust bubbles while
positioning the net under a fish school. Bubbles ascending through the school
disperse the fish.

To capture fish which remained in or near kelp fronds, one side of the net was
wrapped around the plant and the divers ascended with the net in this fashion.
Fishes in the fronds were frightened into the net as it was lifted. Schools of fish
hovering over drift algae on sand bottoms were caught using the net in a
seine-like manner. Here a third diver was useful to herd the fish toward the
approaching net.

After a "scoop", the net and captured fish were taken to the awaiting boat.
There, an on-board assistant quickly removed the fish, placed them in holding
tanks, and returned the net to the divers for another "scoop". Generally, the
entire procedure took 5 to 1 0 min. This was difficult work for the divers, requiring
much swimming and many descents and ascents. About 20 to 25 lifts could be
made in a day by one team. Additional divers were useful to distribute the
workload.

In terms of catch-per-unit-of-effort, the net was most successful when used
to catch juvenile blue rockfish, Sebastes mystinus; juvenile kelp rockfish, Se-
bastes atrovirens; and kelp surfperch, Brachyistius frenatus. juvenile blue rock-
fish were captured in open areas between kelp plants, juvenile kelp rockfish
were caught by wrapping plants, and kelp perch were captured beneath the
canopy. Also taken were four other species of juvenile rockfish, three species

NOTES 307

of adult rockfish, and eleven other incidental fish species.

The efficiency with which the net captures fishes is affected by a number of
factors including water depth, transparency, and wariness of fishes to the divers
as well as the species of fish and size of the individuals. Small, ca. 65 mm (2.5
inches) total length (tl) juvenile blue rockfish form dense schools having many
individuals which are more easily captured than the faster swimming larger
juveniles, ca. 100 mm (4 inches) tl that form loose schools. On one occasion
over 2,500 small juvenile blue rockfish were captured in a single "scoop". An
average of 5,000 (range 2,700 to 9,100) fish were captured during each day of
the 3-week study.

— Kim McCleneghan and James L. Houk, Calif. Dept. of Fish and Came, Opera-
tions Research Branch, 2201 Carden Road, Monterey, California 93940. This
work was performed as part of Dingell-Johnson project California F-25-R,
''Central California Marine Sportfish Survey, " supported by Federal Aid to Fish
Restoration funds. Accepted for publication March 1978.

SIGHTING OF A CALIFORNIA SEA LION,
ZALOPHUS CALIFORNIANUS CALIFORNIANUS,
IN THE SACRAMENTO-SAN JOAQUIN ESTUARY

It is becoming evident that sea lions are using estuaries and rivers of the west
coast of North America for purposes not yet understood. This paper further
documents such use.

We are reporting the sighting of a pinniped, tentatively identified as a Califor-
nia sea lion, in the Sacramento-San Joaquin Estuary on 20 January 1976. The
sighting was made between 1630 and 1700 hours on a sunny, calm afternoon.
The sea lion was observed from a boat as close as 30 m (100 ft). Identification
was based on several factors. Of the seven species of pinnipeds reported (Frey
1971; Daugherty 1972; Fed. Reg. 1975) from the California coast and adjacent
islands, the two species observed most often are, according to Frey (1971 ), the
California sea lion and Stellar sea lion, Eumetopias jubatus. The pinniped we
report had a silhouette most closely matching that of Zaiophus californianus as
given by Daugherty (1972). The animal had a dark-brown head with a distinc-
tive light-colored muzzle. The muzzle was longer and more pronounced than
that of a Stellar sea lion, and it merged into a sharply sloped forehead.

This sighting is the second record of a California sea lion in the estuary since
May 1973. The first, reported by Paulbitski (1974), was a juvenile California sea
lion sighted and captured in the Mokelumne River near Thornton.

The sea lion reported here was swimming east near the shoreline across from
the Pittsburg Marina (Lat 38°02'22" N, Long 12r52'50"W). It was followed by
boat to the mouth of Middle Slough (Lat 38°01'50" N, Long 12r50'55"W). At
no time did the sea lion seem disoriented, but continued to swim steadily
eastward. We passed beyond it by several hundred meters and delayed in a
small embayment. Minutes later it passed us as it headed on upstream.

We had measured some physical parameters of the water a few minutes
before we first spotted the sea lion. The measurements were made about 1 .6 km
( 1 mile) downstream, south of Chipps Island, midchannel, at a depth of 1 m (3.3

308 CALIFORNIA FISH AND CAME

ft) with Martek temperature and salinity meters. We recorded a temperature of
9 C (48 F) and a salinity of S^'/oo- The tide was flooding to high high water. River
discharges were not especially high because of low rainfall for the year.

The reason (s) that California sea lions enter the Sacramento-San Joaquin
Estuary is (are) unknown. Adult and subadult male California sea lions migrate
northward along the California coast in the fall and winter (Peterson and Bar-
tholomew 1967; Braham 1974; Fed. Reg. 1975). Migration may increase the
abundance of animals in the San Francisco area, but any association with move-
ments into less saline water remains unexplained. Exploration for food or territo-
ry may be involved. Stellar sea lions, also for reasons unknown, travel 35 to 70
miles upstream from the sea in northern California rivers (Paulbitski 1974).

Hopefully, future accumulation of data on sea lions in west-coast estuaries and
rivers will lead to understanding of their use of these waters.

ACKNOWLEDGMENTS

We wish to thank Dave Zeiner of the Marine Resources Branch, California
Department of Fish and Came, for his assistance in searching the literature. Also,
we thank Dan Varoujean of the University of California at Davis for his help with
the identification.

REFERENCES

Braham, H. W. 1974. The California sea lion on islands off the coast of San Luis Obispo County, California. Calif

Fish and Game, 60(2): 79-83.
Daugherty, A. E. 1972. Marine Mammals of California, 2nd rev. Calif. Dept. Fish and Game, Sacramento. 90 p.
Federal Register. Notices. Tuesday, July 22, 1975. 40(141): 30688-9.
Frey, H. W. (ed.). 1971. California's living marine resources and their utilization Calif. Dept. Fish and Came,

Sacramento. 148 p.
Paulbitski, P. A. 1974. Pinnipeds observed in rivers of northern California. Calif. Fish and Game, 60 (1): 48-49.
Peterson, R. S., and G. A. Bartholomew. 1967. The natural history and behavior of the California sea lion. Amer.

Soc. Mammal., Spec. Publ. (1): 1-79.

— Richard M. Sitts, Stephen P. Hayes, and Allen W. Knight, Hydrobiological
Laboratory, Department of Land, Air and Water Resources, Water Science
and Engineering Section, University of California, Davis, California 95616.
Accepted for publication June 1977.

309
BOOK REVIEWS

Birds of the Yosemite Sierra — A Distributional Survey.

By David Gaines, Col-Syl Press, 1494 MocArthur Blvd., Oakland, CA, 1977; xxviii + 153 p., illustrated.
$6.75 paperback.

The value of this regional avifauna analysis became obvious even before I finished reading the
introduction. Not one to miss the smallest detail, Gaines has compiled an extraordinary amount of
information on the historical and present status of the birds of what he calls the Yosemite Sierra.
The region covered includes the Sierran Crest from Mt. Lewis south to Mammoth Pass, the Ritter
Range, Yosemite National Park, and a similar size area east of the crest from Bridgeport Valley south
to Crowley Reservoir.

The introduction includes descriptions of 16 habitat types in the region with accompanying lists
of birds associated with each. Also, there are sections on nomenclature, terminology, human impact,
and bird watching.

The text consists of species accounts for the 285 birds observed in the Yosemite Sierra. Each
account contains information on abundance, seasonal occurrence, altitudinal and regional distribu-
tion, habitats utilized, and nesting. Representative or probable breeding localities are given for
species known or suspected to be nesting in the region. Historical comparisons are made and the
effects of development, habitat modification and human activity are discussed. The accounts cover
species that have been extirpated from the region (e.g., harlequin duck), those that are declining
(e.g., willow flycatcher), and some that are increasing their distribution and numbers (e.g., brown-
headed cowbird ) . One especially interesting section deals with field identification of the five similar
species of f/77/9/c''onc?x flycatchers of the region. Gaines provides many clues for easier identification
of these confusing birds.

Data for this book have come from all known published sources and the personal journals of many
bird watchers and ornithologists. The thoroughness of this survey was greatly enhanced by the
contributions of these thoughtful note-takers.

The author points out many unanswered questions concerning migration, disjunct distribution, and
breeding status. For example, nests of common merganser and hermit warbler have not been found
in the region, although both are known to breed there.

Whether a professional ornithologist or an amateur bird watcher, you will find this book valuable.
It is a must for anyone conducting avian research in the Yosemite Sierra, but its application is not
restricted to this region. The information presented on seasonal and altitudinal distribution and
habitat selection can be applied to similar areas outside the region. Hopefully, this book will stimulate
the publication of analyses for other regions, thereby providing the framework with which our avian
populations may be continually monitored. — Robert Lee

The Complete Fisherman's Catalog.

By Harmon Henkin; J. B. Lippincott Co., N.Y., 1975; x + 461 p., illustrated, $7.95.

Harmon Henkin's "The Complete Fisherman's Catalog" is just that — complete. It took me a
helluva long time to review this book because it is so complete and is really fascinating reading.
You can sit down and read it for hours or pick it up and glance through it for a few minutes. Basically,
It is divided into three main sections: Fly Fishing Tackle; Tackle for Spinning, Baitcasting, Trolling,
and Related Techniques; and Service and Accessories. Each subsection, for example the one on fly
reels, starts with a brief paragraph on "what we looked for in quality" followed by an alphabetical
listing and review/opinion of the top of the line products. No prices are given, which would date
the catalog too quickly, but the book is profusely illustrated with pictures of the products, flies, fish,
and old fishing prints. I have faith in the author's opinion and the products he lists because I've used
them myself and, in the vast majority of the instances, agree with him. Interspersed among all the
discussion of items of fishing tackle are notes on game fish, recipes, a short novel by the author,
articles on tackle construction, repair or care, and how-to articles by the author or other well-known
outdoor authors.

I can recommend this book not only for its information value but also for its entertainment value;
well worth the $7.95.— /C. A. Hashagen, Jr.

310 CALIFORNIA FISH AND CAME

Fishwatchers' Guide To the Inshore Fishes of the Pacific Coast

By Daniel W. Gotshall; Sea Challengers, Monterey, California, 1977; 108 p. color plates; $8.95 soft cover

The Fishwatchers' Guide is a compact accurate guide identifying 93 commonly observed Pacific
coast fish. The scope of the guide is limited to those species most commonly found in waters from
10 to 150 ft. The well known large game fish and the very small shallow water species are not
included. Only those species that can be identified alive and in the water are included. Thus the
guide is excellent for identifying fish observed while scuba diving.

Some natural history information and distinguishing physical characteristics or field marks are
provided for each species. Full color photographs of living specimens in their natural habitat are also
included for all but three species.

The author is a prize-winning underwater photographer. Most of the 95 color plates reflect this
prize winning ability, especially the coverage of the rockfish family. There are, however, a few plates
that do not depict the identified species well. The natural history information, the keys to family,
and the generally excellent photographs make this guide a handy reference for the non-specialist
as well as a nice supplement for the specialist. — Fred Wendell

Poissons de Nouvelle Caledonie et Nouvelles Hebrides

By Pierre Fourmanoir and Pierre Laboute. Editions du Pacifique, 6 rue Casimir Le Lavigne, 75006 Paris,

France. 1976. 376 pp. $39.95.

More than 800 exquisite color photographs grace the pages of this beautiful volume. Obviously,
it was intended for a place of honor on a coffee table or similar clearly-visible spot where a host
or hostess could impress the afternoon or evening bridge-playing crowd, tea drinker, occasional
visitor, or partygoer. This it will do admirably, but it also will serve as an excellent reference for
identifying a myriad of fishes that inhabit the reefs and nearby waters of New Caledonia and New
FHebrides.

The first 18 pages introduce very briefly some of the physical, social, and economic attributes of
these tropical isles, and 21 carefully-selected photos supplement perfectly the short written accounts.
This section is followed by chapters on fisheries, past and present, and a few remarks concerning
fish anatomy, classification, taxonomy, vernaculars, and life styles.

The next 16 chapters (4 through 19) deal with various "natural" groups of fishes and/or fish
families (e.g., serranids, lutjanids, labrids and parrotfishes, nocturnals, pomacentrids and anemone-
fishes, sharks and rays, etc.). Although not all genera or species are covered, and not all coverage
is identical, one could certainly arrive at precise identification for a vast number of species inhabiting
the waters of this area. The superb photos, most in natural habitat, are of such excellent quality that
they alone would suffice in most instances.

The one drawback to the volume is the heavy, glossy paper on which it has been printed. While
this is ideal for reproducing color photos, under no circumstances will it stand up to field usage or
moisture of any type. In fact, the weight of the pages of an inscribed copy sent me from New
Caledonia had caused them to tear loose from the binding while in transit. On the other hand, today's
postal system is capable of destroying a metal book with a welded binding.

I am informed that this book is not for sale in the USA, so it must be purchased directly from the
publisher as noted above. — John E. Fitch

New Techniques for Catching Bottomfish

By Doug Wilson and Fred Vender Werff; Gordon Soules Book Publishers, Vancouver, B.C. Canada, 1977;
150 p. $4.95.

This is a complete book on fishing for bottomfish, that myriad of species comprised mainly of
rockfish ( Sebastes sp) . Bottomfish are largely overlooked by northeastern Pacific recreational an-
glers in favbr of salmon; only in California, where rockfish is the leading species in numbers caught
by marine anglers, are there well developed recreational fisheries.

The authors describe how to make lures, jigs, and terminal gear and they recommend rod, reel,
and line combinations. They describe how to safely get to and from fishing spots, how to find fish,
catch them, identify them, care for the catch, fillet fish, and finally cook the catch.

The new techniques include the use of plastic worms in various terminal arrangements. Other
lures, jigs, and bait are also described for bottomfish along with fishing techniques for use from shore
to 400 ft depths. The authors share techniques that less generous anglers would keep secret.

Doug Wilson's prize winning photographic skills are known to many. The photographs in this book

REVIEWS 311

may not rank with Doug's best, but they add immeasurably to the text.

Editorial comments are that the copper rockfish on pages 13 and 30 look like quillback rockfish
(Sebastes maliger), which they also have the specific name mispelled malinger. A caution to amateur
Chinese chefs is that the recipe for steamed rockfish on page 106 calls for at least 4 times the soy
sauce needed. The ginger root is best used to garnish the fish while steaming. Use y^ cup of soy
sauce, forget the water, the sauce simmering, or stuffing. Baste the cooked fish with soy sauce and
oil and garnish the fish with the sliced onion and Chinese parsley and expect a gourmet's delight.

Few authors consider conservation and Wilson and Vander Werff's fishing ethic should be heeded
by all anglers; "Appreciate this resource; take as much as you can reasonably use regardless of legal
catch limits. Take care of your catch, and don't waste it. The fish you leave today will be there for
your sport tomorrow and for generations of anglers that follow you."

The $4.95 price tag may seem high for a 1 50 page paperback but don't judge this book by its cover;
the value is in its content. — Tom Jow

312 CALIFORNIA FISH AND GAME

INDEX TO VOLUME 64
AUTHORS

Ashcraft, Cordon A.; see Salwasser, Holl, and Ashcraft, 38-52
Barton, Michael: First Oregon Records for Two Blennioid Fishes, 60-61
Bogiatto, R. ).: see Yocom, Bogiatto, and Eshelman, 302-305

Bottrotf, Lawrence J., and Michael E. Lembeck: Fishery Trends in Reservoirs of San Diego County, California,
Following the Introduction of Florida Largemouth Bass, Micropterus salmoides (londanus, 4-23

Brewer, Gary D.: Reproduction and Spawning of the Northern Anchovy, Engraulis mordax, in San Pedro Bay,
California, 175-184

Brophy, Pat: see Fay, Vallee and Brophy, 104-116

Cavender, Ted M.: Taxonomy and Distribution of the Bull Trout, Salvelmw, conlluenius (Suckley), from the
American Northwest, 139-174

Cox, James L,: see Harding, Cox, and Pequegnot, 53-59

Crase, Frederick T., and Richard W. Dehaven: Food Selection by Five Sympatric California Blackbird Species,
255-267

Dexter, Deborah M.: The Infauna of a Subtidal, Sand-bottom Community at Imperial Beach, California, 268-279
Eshelman, J. C: see Yocom, Bogiatto, and Eshelman, 302-305

Fay, Rimmon C, lames A. Vallee, and Pat Brophy: An Analysis of Fish Catches Obtained with an Otter Trawl in
Santa Monica Bay, 1969-73, 104-116

Fitch, John E., and Steven A. Schultz: Some Rare and Unusual Occurrences of Fishes off California and Ba)a
California, 74-92

Eraser, J. C: see Scott, Hewitson, and Eraser, 210-218

Fritzsche, Ronald A.: The First Eastern Pacific Records of Bulleye, Cookeolus boops. (Bloch and Schneider, 1801 )

(Pisces, Priacanthidae), 219-221
Gall, G. A. E.: see Gold, Gall, and Nicola, 98-103

Gold, J. R., G. A. E. Gall and S. J. Nicola: Taxonomy of the Colorado Cutthroat Trout (Salmo clarki pleuriticus)
of the Williamson Lakes, California, 98-103

Cotshall, Daniel W: Relative Abundance Studies of Dungeness Crabs, Cancer magister, in Northern California,
24-37

. Catch-per-Unit-of-Effort Studies of Northern California Dungeness Crabs, Cancer magister. 189-199

. Northern California Dungeness Crab, Cancer magister, Movements as Shown by Tagging, 234-254

Haaker, Peter L.; Observations of Agonistic Behavior in the Treefish, Sebastes serriceps (Scorpaenidae), 227-228

Harding, Lawrence W., Jr., James L. Cox, and John E Pequegnat: Spring-Summer Phytoplankton Production in
Humboldt Bay, California, 53-59

Hayes, Stephen P.: see Sitts, Hayes, and Knight, 307-308

Hewitson, ].: see Scott, Hewitson, and Fraser, 210-218

Holl, Stephen A.: see Salwasser, Holl, and Ashcraft, 38-52

Houk, James L.: see McCleneghan and Houk, 305-307

Klingbeil, Richard A.: Sex Ratios of the Northern Anchovy, Engraulis mordax. Off Southern California, 200-209

Knight, Allen W.: see Sitts, Hayes, and Knight, 307-308

Lembeck, Michael E.: see Bottroff and Lembeck, 4-23

Lo, Nancy C, H.: California Ocean Shrimp Mesh Experiment, 280-301.

Loughlin, Thomas R.: Harbor Seals in and Adjacent to Humboldt Bay, California, 127-132

MacCall, Alec: A Note on Production Modeling of Populations with Discontinuous Reproduction, 225-227

McCleneghan, Kim, and James L. Houk: A Diver-Operated Net for Catching Large NLimbers of luvenile Marine

Fishes, 305-307
Nicola, S. J.: see Gold, Gall, and Nicola, 98-103

Olson, Robert E.: Parasites of Silver Salmon (Coho) and King (Chinook) Salmon from the Pacific Ocean off
Oregon, 117-120

Pelzman, Ronald J.: see Rawstron and Pelzman, 121 123

. Hooking Mortality of Juvenile Largemouth Bass, Micropterus salmoides, 185-188

Pequegnat, John E.: see Harding, Cox, and Pequegnat, 53-59

Rawstron, Robert R., and Ronald J. Pelzman: Comparison of Floy Internal Anchor and Disk-Dangler Tags on

Largemouth Bass (Micropterus salmoides) at Merle Collins Reservoir, 121-123
Salwasser, Hal, Stephen A. Holl, and Gordon A. Ashcraft: Fawn Production and Survival in the North Kings River

Deer Herd, 38-52

INDEX

313

Schott, lack W.: A Hermaphroditic California Halibut, Paralichthys calitornicus, 221-222

Schultz, Steven A.: see Fitch and Schultz, 74-92

Scoppettone, C. Gary, and Jerry |. Smith:. Additional Records on the Distribution and Status of Native Fishes in

Alameda and Coyote Creeks, California, 61-65
Scott, D., J. Hewitson, and j. C. Fraser: The Origins of Rainbow Trout, Sa/mo gairdneri Richardson, in New Zealand,

210-218
Sitts, Richard M., Stephen P. Hayes, and Allen W. Knight: Sighting of a California Sea Lion, Zaiophus californlanus

calilornianus, in the Sacramento-San loaquin Estuary, 307-308

Smith, Gary E.: An Evaluation of Disk-Dangler Tag Shedding by Striped Bass (Morone saxatills) in the
Sacramento-San Joaquin Estuary, 93-97

Smith, Jerry J.: see Scoppettone and Smith, 61-65

Span, |ohn A.: Successful Reproduction of Giant Pacific Oysters in Humboldt Bay and Tomales Bay, California,
123-124

Tasto, Robert N.: Spinal Column Deformity in a Pile Surfperch, Damalichthys vacca, ITi-lTi
Vallee, James A.: see Fay, Vallee, and Brophy, 104-116

Yocom, Charles F.: Status of the Oregon Ruffed Grouse in Northwest California, 124-127

Yocom, Charles F., R. j. Bogiatto, and |. C. Eshelman: Migration of American Coots Wintering in Northwestern
California, 302-305.

SCIENTIFIC NAMES

Acanthocybium solanderi: 85
Acartia tonsa: 182
Acipenser medlrostris: 74
Age/a /us phoeniceus: 255
Ageliaus tricolor: 255
Ainus rubra: 1 26
Anas amehcana: 302
Anas platyrhynchos: 302
Ancinus granulatus: 268
Agelaius phoeniceus califorinicus: 255
Agelaius phoeniceus caurinus: 255
Agelaius phoeniceus nevadensis: 255
Anoplarchus insignis: 60
Anoplarchus purpurescens: 60
Aqulla chrysaetos: 41
Archoplites interrupt us: 62
Benthodesmus elongatus pacificus: 74
Bonasa umbellus sabini: 1 24
Brachyistius frenatus: 306
Brachyphallus crenatus: 1 1 8
Callorhinus ursinus: 1 27
Cancer magister: 3, 24, 189, 234
Canis latrans: 41
Carassius auratus: 65
Carcharhinus lamiella: 11
Carcharhinus obscurus: 74
Carthamus tinctorius: 256
Catostomus occidentalis: 63
Cebidichthys violaceus: 60
Citharichthys sordidus: 79
Citharichthys stigmaeus: 1 04
Coelonnchus scaphopsis: 74
Cookeolus boops: 83, 219
Coryphopterus nicholsii: 228
Cottus aleuticus: 64
Cottus asper: 62
Cottus gulosus: 62
Crossotrea gigas: 123
Cryptomya calif arnica: 21 'i
Cryptopsaras couesii: 74
Cynodon dactylon: 257
Cyprinus carpid: 63
Damalichthys vacca: 223
Dendraster excentricus: 268-279
Diaphus theta: 78
Diastylopsis tenuis: 278
Dosidicus gigas: 11

Slops aftinis: 74
Embiotoca jacksoni: 1 09
Engraulis mordax: 175, 180, 200
Entosphenus tridentatus: b2
Eohaustorius washingtonianus: 268
Epinephelus niveatus: lA
Eumetopias jubata: 127, 307
Euphagus cyanacephalus: 255
Euphilomedes carcharodonta: Hi
Fells concolor: 41
Fulica amehcana: 302
Gadus macrocephalus: lA
Cambusia affinis: 65
Casterosteus aculeatus: 63
Cempylus serpens: 85
Gila crassicauda: 62
Glyptocephalus zachirus: 90, 1 09
Goniada littorea: 278
Gonichthys tenuiculum: 83
Henneguya salmonicola: 1 1 8
Hesperoleucus symmetricus: 62
Hardeum vulgare: 256
Hyperposopon argenteum: 11
hlysterocarpus traski: 62
Icelinus quadriseriatus: 104
Ictalurus nebulosus: 1 2 1
Icalurus punctatus: 1 2 1
Idiacanthus antrostomus: 90
Lampetra richardsoni: 62
Lavina exilicauda: M
Lepeophtheirus salmonis: 120
Lepidocybium flavobrunneum: lA
Lepomis cyanellus: 65
Lepomis macrochirus: Gi, 121
Leptocuma forsmani: 211
Leptocuma tenuis: 273
Lynx rufus: 41
Lyopsetta exilis: 79, 109
Lythrypnus dalli: 228
Magelona pitelkai: 21 i
Mandibulophoxus gilesi: 273
Merluccius productus: 90
Micropterus salmoides: <oi, 121, 185
Micropterus salmoides floridanus: 3,
Mirounga angustirostris: 127
Molothrus a ten 255
Molothrus ater artemisiae: 255

314

CALIFORNIA FISH AND CAME

Molothrus ater obscurus: 255

Morone sjxati/is: 93, 121

Mvliobatus longirosths: 74

Mytilus californianus: 78

Mytius edulis: 1 2 3

Myxidium minlen: 1 1 8

My\u<ioma squamalis: 118

Nanophyetui ialmmcola: 1 1 7

Nipporhynchus trachuri: 1 20

Nolemlgonus crvioleucas: 187

Odocoileus he mi on us californicus: 38

Odacoileus hemionus columbianus: 48

Odocoileus virgi planus: 45

Ollvella baetica: 75, 268

Oncorhynchus gorbuscha: 1 18

Oncorhvnchus kisutch: 117

Oncorhynchus nerka: 1 1 8

Oncorhynchus tshawytscha: 117, 146, 211

Orthodon mlcrolepldotus: 63

Oryza sativa: 255

Ostrea lurlda: 123

Pandalus jordanl: 280

Paralabrax auroguttatus: 7 A

Parallchthys californicus: 221

Paraphoxus biscuspidatus: 278

Paraphoxus epistomus: 268

Pe/"Cd flavescens: 121

Phanerodon f ureal us: 109

Phoca vltullna: 127

PImelometopon pulchrum: 228

Plagioporus shawl: 118

Pleurogrammus monopteryglus: 74

Pleuroncodes pi an I pes: 83

Pogonlchthys macrolepldotus: 62

Pomoxis nigromaculatus: 63

Priacanthus alalaua: 83

Priacanthus arenatus: 84

Priacanthus cruenlatus: 74

Priacanthus hamrur: 84

Priacanthus macaracanthus: 84

Priacanthus meekl: 84

Priacanthus tavenus: 84

Prionopslo malmgreni: 278

Prosoplum wllllamsoni: 1 67

Psettlchthys melanostlctus: 74

Pseudoprlacanthus serrula: 83

Pseudotsuga menzelsll: 126

Pteraclls aestlcola: 7 A

Pteraclls carollnus: 75

Pteraclls velliera: 75

Ptychochellus grandls: 62

Rang Iter tarandus: 45

Rexea solanderl: 85

Rhinichthys osculus: 62

Rhynchospio arenlcola: 273

Ruvettus pretlosus: 74

Salmo aguabonlta: 99

Sal mo apache: 101

Salmo balrdii: 145

Salmo Campbell 1 : 145

5<}//T70 clarkl:99. 167, 216

Salmo clarkl henshawl: 99, 211

Salmo clarkl lewisl: 98

Salmo clarkl pleurlticus: 98

Salmo clarkl stomas: 99

Salmo confluentus: 140

Salmo tontlnalls: 212

5.?//770 Cairdnen: 62, 101, 121, 210

Salmo parkel: 145

Salmo regalls: 2 1 1

Salmo spectabllls: 140

Salmo trutta: 216

Salvellnus alplnus: 139

Salvellnus anaktuvukensis: 170

Salvellnus balrdll: 1 70

Salvellnus confluentus: 139-174

Salvellnus fontlnalls: 165, 212

Salvellnus malma: 1 39

Salvellnus namaycush: 152, 163, 171

Salvellnus spectabllls: 145-148

Salvellnema walkerl: 1 1 7

Scoloplos armlger: 273

Scomber scombrus: 85

Scomberomorus concolor: 85

Sebastes atrovirens: 228, 306

Sebastes carnatus: 228

Sebastes diploproa: 90

Sebastes melanostomus: 90

Sebastes mystlnus: 306

Sebastes nebulosus: 7 A

Sebastes serrlceps: 227

Sequoia sempervlrens: 1 26

Sorghum halepense: 257

Sorghum vulgare: 256

Splophanes bombyx: 278

Squalus acanthlas: 90

Svmphurus atricauda: 104

Svncoelium katuwo: 118

Taractes longiplnnis: 7h

Tarachtichthys stelndachnerl: 74

re//wc) buttoni: 278

Thalanessa splnosa: 273

Thunnus alalunga: 75

Thunnus albacares: 86, 220

Thunnus thynnus: 75

Thyrsltes atun: 85

Tritlcum aestlvum: 256

Tubuloveslcula llndbergi: 1 1 8

L'rsu5 amerlcanus: A 1

Vlnclguerrla lucetla: 83

Xanthocephalus xanthocephalus: 255

Xenogramma carlnatum: 85

Xiphlas gladlus: 86

Zaiophus californianus: 127

Zaiophus californianus californianus: 307

Z(y cristatus: 74

SUBJECT

Alameda Creek: Additional records on distribution and status of native fishes in, 62-65

Anchovy, Northern: Reproduction and spawning, in San Pedro Bay, California, 175-184; Sex ratios, off Southern

California, 200-209.
Baja California: Some rare and unusual occurrences of fishes, 74-92.
Bass, Florida largemouth: Fishery trends in reservoirs of San Diego County, California, following the introduction

of, 4-23.
Bass, largemouth: Comparison of floy internal anchor and disk-dangler tags, 121-123.
Bass, striped: An evaluation of disk-dangler tag shedding, 93-97.
Blackbird: Food selection by five sympatric California species, 255-267.
Blennioid fishes: First Oregon records, 60-61,

INDEX 315

Bulleye: First Eastern Pacific records of, 219-221.

Crabs, dungeness: Relative abundance studies, 24-37; Catch-per-unit-of effort studies, 189-199; Movements as
shown by tagging, 234-254.

Coots, American: Migration of, in Nortfiw'estern California, 302-305.

Coyote Creek: Additional records on distribution and status of native fishes in, 62-65.

Deer: Fawn production and survival, 38-52.

Deformity: Spinal column, in pile surfperch, 223-225.

Distribution: Bull trout, from American Northwest, 139-174.

Fishes: Distribution status in Alameda and Coyote Creeks, California, 62-65; Rare and unusual occurrences, 74-92;
Analysis of catches obtained with an otter trawl, 104-116; Diver-operated net for catching large numbers of
juvenile marine, 305-307.

Grouse, Oregon ruffed: In Northwestern California, 124-127.

Halibut: A hermaphroditic, California, 221-222.

Humboldt Bay: Spring-summer phytoplankton production in, 53-59; Successful reproduction of giant pacific

oysters, 123-124; Harbor seals in and around, 127-132.
Imperial Beach: Infauna of subtidal, sand-bottom community, 268-279.
Infauna: Subtidal, sand-bottom community, 268-279.
Kings River, North: Fawn production and survival in deer herd, 24-37.

Merle Collins Reservoir: Comparison of floy internal anchor and disk-dangler tags on largemouth bass, 121-123.
Mesh Experiment: California Ocean Shrimp, 280-301
Migration: American coots wintering in Northwestern California, 302-305.
Net: Diver-operated, for catching large numbers of juvenile marine fishes, 305-307.
New Zealand: Origins of rainbow trout, 210-218.

Oysters, giant pacific: Successful reproduction in Humboldt Bay and Tomales Bay, California, 123-124.
Parasites: Silver salmon and king salmon, 117-120.

Phytoplankton: Spring-summer production in Humboldt Bay, California, 53-59.
Production: Fawn, in North Kings River deer herd, 38-52; Spring-summer phytoplankton, in Humboldt Bay,

California, 53-59.

Production Modeling: Populations with Discontinuous Reproducton, 225-227.

Rare: Occurrences of fishes off California and Baja California, 74-92.

Records: Two blennioid fishes, 60-61; Distribution and status of native fishes in Alameda and Coyote Creeks,
California, 62-65; First Eastern Pacific, for bulleye, 219-221.

Reproduction: Giant pacific oysters, 123-124; Northern Anchovy, in San Pedro Bay, California, 175-184.

Reviews: Murex shells of the world: an illustrated guide to the muricidae, 66; In the ring of the rise, 66; Fishes of
the world, 67; Waterfowl of North America, 67; Advanced bass fishing, 67; Fly tackle, 68; Classic rods and
rodmakers, 68; The essential flytier, 68; Fish remains in archaeology and paleo-environmental studies, 133;
The caddis and the angler, 133; Bright rivers, 229; Fresh and saltwater fishes of the world, 229; Inland fishes
of California, 229; Birds of the Yosemite Sierra — a distributional survey, 309; The complete fisherman's catalog,
309; Fish watchers' guide to the inshore fishes of the Pacific coast, 310; Poissons de nuvelles hebrides, 310;
New techniques for catching bottom fish, 310.

Sacramento-San Joaquin Estuary: Tag shedding by striped bass, 93-97; Sighting of California sea lion, 307-308.

Salmon, king: Parasites of, 117-120.

Salmon, silver: Parasites of, 117-120.

Santa Monica Bay: Analysis of fish catches obtained with an otter trawl in, 104-116.

San Diego County, California: Fishery trends in reservoirs of, following introduction of Florida largemouth bass,
4-23.

San Pedro Bay: Reproduction and spawning of northern anchovy in, 175-184.

Seals, harbor: In and adjacent to Humboldt Bay, 127-132.

Sea lion, California: Sighting of, in Sacramento-San loaquin Estuary, 307-308.

Shrimp, ocean: Mesh experiment, 280-301.

Spawning: Northern anchovy, in San Pedro Bay, 175-184.

Status: Native fishes in Alameda and Coyote Creeks, California, 62-65; Oregon ruffed grouse in Northwestern
California, 124-127.

Surfperch, pile: Spinal column deformity, 223-225.

Tagging: Dungeness crab, movements as shown by, 234-254.

Tags, Disk-Dangler: Evaluation of, by striped bass, 93-97.

Taxonomy: Colorado cutthroat trout, 98-103; Bull trout, from American Northwest, 139-174.

316 CALIFORNIA FISH AND CAME

Tomales Bay: Successful reproduction of giant pacific oysters in, 123-124.

Treefish: Agonistic behavior in, 227-228.

Trout, Bull: Taxonomy and distribution, from American Northwest, 139-174.

Trout, Colorado cutthroat: Taxonomy of, in the Williamson Lakes, California, 98-103.

Trout, Rainbow: Origins of, in New Zealand, 210-218

Williamson Lakes: Taxonomy of the Colorado cutthroat trout in the, 98-103.

Photoelectronic composition by
c:alifohma office of statf printing
77851—800 7-78 4.,50O LDA

FISH AND GAME COMMISSION
NOTICE OF MEETINGS RELATIVE TO
1979 SPORT FISHING REGULATIONS

NOTICE IS HEREBY GIVEN that the Fish and Game Commission/ pursuant
to the authority vested by Sections 200-221 of the Fish and Game Code, will
meet on October 6, 1978, at 9:00 a.m. in the Auditorium of the Resources
Building, 1416 Ninth Street, Sacramento, California to receive recommenda-
tions as to what regulations should be made relating to fish, amphibia and
reptiles for 1979.

Notice is also given that the Fish and Game Commission will meet on
November 10, 1978, at 9:00 a.m. in the Supervisors' Chambers of the Shasta
County Courthouse, Redding, California, for public discussion of and presenta-
tions of objections to the proposals presented to the commission on October
6, 1978, and after considering such discussion and objections, the commission
shall announce the regulations which it proposes to make relating to fish,
amphibia and reptiles.

Notice is also given that the Fish and Game Commission will meet on
December 8, 1978 at 9:00 a.m. in Room 1138 of the State Building, 107 S.
Broadway, Los Angeles, California to hear and consider any objections to
its tentative approvals in relation to fish, amphibia and reptiles for the 1979
sport fishing season.

Environmental plans with respect to the Department's proposals will be on
file and available for public review in the commission office, 1416 Ninth
Street, Sacramento, California 95814 after October 6, 1978.

The Fish and Game Commission has determined that there are no new
costs to local government, pursuant to Section 2231 of the Revenue and Tax-
ation Code.

FISH AND GAME COMMISSION

Leslie F. Edgerton
Executive Secretary

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