Special scientific report

371

EXPERIMENTAL HARVEST OF THE
STELLER SEA LION IN ALASKAN WATERS

Marine Biological Laboratory
WOODS HOLE, MASS.

SPECIAL SCIENTIFIC REPORT-FISHERIES Na 371

UNITED STATES I^EPARTMENT^QH^^

FISH AND WILDLIFE SERVICE

United States Department of the Interior, Stewart L,. Udall, Secretary

Fish and Wildlife Service, Arnie J. Suomela, Commissioner

Bureau of Commercial Fisheries, Donald L. McKernan, Director

EXPERIMENTAL HARVEST OF THE STELLER SEA LION

IN ALASKAN WATERS

by

Fredrik V. Thorsteinson, Richard W. Nelson

and
Dexter F. Lall

United States Fish and Wildlife Service
Special Scientific Report- -Fisheries No. 371

Washington, D. C,
Janury 1961

This work was financed by the Bureau of
Commercial Fisheries under Contract No.
14-17-001-218, with funds made available under
the Act of July 1, 1954 (68 Stat. 376), commonly
known as the Saltonstall-Kennedy Act.

ii

CONTENTS

Page

Introduction 1

The experimental harvest. 2

Equipment and facilities of the Arctic Maid 2

Hunting and retrieving 4

Reactions of sea lions to hunting 5

Processing • 6

Proximate composition of ground sea lion meat 10

Disposition of sea lion meat 11

Discussion 1 1

Summary .................■..*. 14

Literature cited •••• 14

111

EXPERIMENTAL HARVEST OF THE STELLER SEA LION

IN ALASKAN WATERS

by

Fredrik V. Thorsteinson, Bureau of Commercial Fisheries, Juneau, Alaska

Richard W. Nelson, Bureau of Commercial Fisheries, Seattle, Wash.

Dexter F. Lall, Alaska Department of Fish and Game, Kodiak, Alaska*

ABSTRACT

During the summer of 1959, a commercialfishing company, vmder
contract to the Bureau of Commercial Fisheries, conducted an experi-
mental harvest of the Steller sea lion (Eumetopias jubata) inAlaska.
During the expedition, 616 sea lions were killed of which 464 were
ultimately processed. The yield was ZOO tons of ground meat and 9 tons
of whole livers, which was packaged in 50-pound bags, frozen, and sold
through established commercial channels to fur farmers for feeding
mink.

INTRODUCTION

The Steller sea lion (Eumetopias
jubata) has been widely condemned by
the fishing industry. Salmon, halibut,
and herring fishermen have been unani-
mous in their complaints about depre-
dations by this mammal. The persist-
ence and uniformity of the complaints
and concern over the declining salmon
pack in Alaska have led to recent in-
tensive study of the Steller sea lions
and their effects on the fisheries.
The Alaska Department of Fish and
Game and the Fisheries Research Insti-
tute of the University of Washington,
through contracts with the Bureau of
Commercial Fisheries, have conducted
studies of the biology of sea lions and
have carried out surveys to study popu-
lation size, distribution, and seasonal
shifts in abundance. Mathisen (1958)
estimates there are at least 150,000

' Formerly a Fishery Aid with the Bureau of Commer-
cial Fisheries, Juneau, Alaska.

sea lions in Alaskan waters, most
of which are found on rookeries
located along the Alaska Peninsiila and
the Aleutian Islands. Individual rookery
counts vary from 25 to 15,000 animals.

The two agencies making the
studies circulated questioiuiaires
throughout the fishing industry to docu-
ment the time, location, and nature of
dajTiage done by sea lions. Returns
from these questionnaires indicate that
salmon fishermen do suffer an economic
loss from sea lion activities, both in
damage to gear and by loss of fish
taken from the gear (Alaska Department
of Fish and Game, 1957).

Halibut fishermen report that at
times sea lions damage or remove so
majiy fish from their gear that it is
not profitable to remain on the halibut
banks. A sample poll of halibut vessels
by the Inter nationail Pacific Halibut
Commission in 1958 brought out that
an estimated 1.3 million povinds of hali-
but were damaged or destroyed on the

grounds between Cape Saint Elias and
the Trinity Islands in the Gulf of Alaska.
At dockside prices this amount of
halibut is worth approximately $270,000
(preliminary statement issued at the
annual meeting of the International
Pacific Halibut Commission, January
1959). As one result of the poll, the
International Pacific Halibut Commis-
sion has required that all fishermen
record depredation in the logbooks
that they keep for the Commission.

Stomach analyses reported in the
literature (Pike, 1958; Mathisen, 1958)
indicate that the diet of sea lions is
varied and that no significant numbers
of commercially important species are
taken. However, most of the stomach
samples were taken fronn sea lions on
rookeries during the breeding season,
and they may not reflect completely
the food habits of sea lions. Food
habits during other seasons of the year
are unknown. Recent evidence obtained
by the Fisheries Research Institute
during a high seas tagging program in
the North Pacific and Bering Sea points
to possible open-sea predation on sal-
mon by sea lions (Mathisen, 1958). At
present it appears that, except when
they are in contact with an active
fishery, sea lions take insignificant
quantities of commercial species with
the possible exception of salmon.

The depredations of sea lions in the
vicinity of active fisheries are serious
because they cause measurable econo-
mic losses by damaging fish and gear
and intangible economic losses by re-
ducing fishing time or frightening fish
away from the gear. Control measures
should be applied in critical areas. Pro-
grams of complete destruction of herds
have been attemptedin the past and have
met rightly deserved criticism and op-
position from conservationists through-
out the nation. Bounty programs were
attempted but have been abandoned. Re-
duction of a herd by a bounty system is
expensive and unwieldy and may fail to
correct the situation, because kills may
not be made at the proper place or time
or in adequate numbers.

A practical approach to the prob-
lem of control may lie in commercial
exploitation of these manamais. Dassow

(1956) and Kyte (1956) investigated
possibilities of utilizing sea lions and
found that both leanmeat and liver were
high in protein and low in oil content.
The protein content was similar to
horse meat and lean whale meat, both
of which are used extensively in animal
feeds. There is a demand for an eco-
nomical meat, with high-protein and
low-fat content, for use as either fur
farm or fish hatchery feed in the
midwestern and western states. Pilot
studies involving harvesting techniques
and handling of sea lions conducted on
Chernabura, one of the Shumagin
Islands, by the Fisheries Research
Institute through a contract with the
Bureau of Commercial Fisheries, indi-
cates that sea lions might be taken
from rookeries in commercial quanti-
ties (Baade, et al.)' As a result, the
Bureau of Commercial Fisheries
awarded a contract in the spring of
1959 to a commercial fishing company,
Arctic Maid Fisheries, Inc., to develop
techniques for harvesting sea lions on
rookeries in Alaskan waters and to
investigate markets for commercial
utilization. The company operates a
freezership, the motor vessel Arctic
Maidi which served as mothership and
base for the operation (fig. 1). It is
the purpose of this report to present
the results of this investigation.

THE EXPERIMENTAL HARVEST

Equipment and Facilities of the Arctic
Maid

The Arctic Maid, adiesel-electric
ship of 960 gross tons, is 186 feet in
length and has a 39-foot beam. Power
to the ship's single screw is furnished
by twin 900-hp. diesel engines that
deliver 1,500 horsepower to the pro-
peller shaft. Two 75-kw diesel gen-
erators supply electric power to the
ship's equipment.

The ship has two 5-ton-capacity
electric cargo winches, located forward
and aft, which were used to hoist ani-
mals aboard and to lower processed
meat into the hold (fig. 2).

' Baade, Robert T., Ole A. Mathisen, and Ron J. Lopp.
In press. Studies on the Steller sea lion (Eumetopias jubata)
on Chernabura Island in the Shumagin area of Alaska
during the summer of 1958.

Figure 1,-- Arctic Maid, mothership used in harvesting sea lions.

//

Figure 2.--Sea lions being hoisted aboard ship.

The refrigeration system of the
Arctic Maid consists of six 6,000-gal-
lon brine tanks, four 8, 000-gallon brine
tanks, and a 600-ton-capacity hold,
cooled by absorption type coils. Cooling
plants are two ammonia compressors
each capable of delivering 70 tons of
refrigeration. (One ton of refrigeration
is defined as cooling necessary to con-
vert 1 tonof water at 32° F. into 1 ton of
ice at 32° F. per 24 hours.)

The processing area was located
forward on the brine tank deck and was
equipped with a boning table, a 15-hp.
meat grinder with 3/4-inch cutting
plates, a conveyor worm, and a metal
hopper from which meat was sacked.

The ship carried two 31 -foot
Bristol Bay-type gill net boats which
were" used to shuttle hunting parties
to the beach and to transport dead
animals. They were also used to pull
dead animals from the beach into the
water.

Members of the working crew,
which numbered 10 men including the
captain, not only worked the ship but
also served as hunters or butchers. The
cook and 3 engineers brought the ship's
complement to 14.

Hunting and Retrieving

The Arctic Maid took sea lions
from five of the many rookeries in
waters of the North Pacific Ocean
between Kodiak Island and Unimak Pass
(fig. 3). The first rookery visited was
Marmot Island, northeast of Kodiak
Island, where 2 weeks were spent in
developing hunting and processing tech-
niques. The methods evolved at Marmot
Island were employed during the re-
mainder of the season. None of the
crew had previous experience in meat
processing. At first they made them-
selves available as the work dictated,
but soon each man had a specific job.

j:P^"1

Ugamak
Island

AKcnc nAio

Figure 3.--Sea lion rookeries harvested by the Arctic Maid, 1959.

The hunting party usually consisted
of three or four men. One of the gill
net boats was used to carry the party
to the beach, and a small skiff or
rubber life raft was used to land them
ashore at the fringe of the harvest
area. The rubber raft was used when
surf conditions precluded use of the
small boat.

Sea lions were shot at fairly
close range with 30.06-c a 1 i b e r
sporting rifles equipped with open
sights. Military ammunition (ordi-
nary 30.06-caliber service ammu-
nition, full jacketed "ball") was
used and served satisfactorily.
Judgment was required in select-
ing animals for shooting. Those
shot near the edge of the water,
if not killed outright, managed to
get into the water and were lost.
It is extremely difficult to retrieve
carcasses of animals killed too
far from the water, since adult males
weigh up to 2, ZOO pounds and fe-
males up to 1,000 pounds (Kenyon
and Scheffer, 1953). Killing ceased
when enough animals, usually about
15, were down to supply a day's
work in processing.

Manila or wire rope chokers placed
through slots cut in the neck hide were
secured to a hauling line attached to the
gill net boat. Animals were then pulled
from the beach into the water by the
boat. Once in the water the carcasses
were easily pulled to the boat- -either
hand over hand or by using a winch.
The hauling line was then freed and
passed ashore again, and the chokers
were used to secure the animals to the
gunwale of the gill net boat for trans-
port to the Arctic Maid.

Reactions of Sea Lions to Hunting

The reactions of sea lions to har-
assment were similar in pattern on all
of the rookeries hunted. Variations
were a matter of the degree to which
the animals reacted. This, in turn, was
dependent upon the stage of the breed-
ing season. Bulls and cows were least
wary at the height of the breeding
season.

The hunting party usually landed
to one side of the group of sea lions
to be hunted, out of sight if possible.
Landing disturbed only nearby animals.
Animals exhibited only slight alarm
over the gill net boat when it was oper-
ated within 80 to 100 yards of the beach.

At the first shots, most animals
showed considerable fright and many
bolted toward the water. The first rush
to the water comprised females without
pups, yovmg animals, and bachelor
bulls. Harem bvills and cows with new-
born pups were extremely reluctant to
leave and either did not move at all or
stopped their flight short of the water's
edge. Continued fire forced these ani-
mals into the water where they milled
slightly offshore and showed a strong
tendency to return. While in the water
the animals displayed great interest
in the activities on the beach but rel-
atively little interest in the boat or
skiff which was often nearer at hand.
Sea lions became increasingly wary
and frightened more readily after suc-
cessive days of shooting. At the first
volley of shots , all but the most stubborn
bulls and cows rushed immediately to
the water. Beaches were quickly cleared
when additional shots were fired.

Continued hunting over the same
area caused an emigration to nearby
rocks or a lateral movement along the
beach if space was available. Emigra-
tion began after 3 to 5 days of hunting.
It was not a mass movement but was
observed as a perceptible thinning in
the ranks of sea lions each day. Young
animals were the first to move. The
pups either moved away because of
fright or were herded by the females.

Harem bulls that were killed were
replaced by idle or bachelor bulls very
quickly. Mathisen (1958) reports that
on Chernabura Island harem bulls were
replaced within less than 30 minutes
after their death and frequently within
10 minutes. A striking example of this
replacement occurred on the Ugamak
Island rookery in Unimak Pass. One
area of this rookery was hunted in-
tensively for 9 days. On the first day
of the hunt, Z5 bulls and approximately

300 cows occupied the area, and many of replacement is unknown, but it oc-

idle bulls were observed on adjacent curred overnight,
rocks and beaches from 300 yards to a

mile away. A total of 156 bulls were The rookeries visited and the re-
killed, an average of 1 7 per day. An suits of the harvest are summarized
additional 12 were wounded. The speed in table 1.

Table 1, -- Summary of experimental sea lion harvest

May 27-
June 10

June 12-
June 24

June 26-
July 8

July 10-
July 11

July 13-
July 14

July 15

Total

Location (Island)

Marmot

Atkins

Ugamak

Jude

Atkins

Chowiet

Total days of hunting

14

14

12

2

2

1

45

Days lost because of weather

5

2

2

0

0

0

9

Days operated

9

12

10

2

2

1

36

Number animals killed or wounded

137

228

179

39

37

10

630

Number animals processed

78

162

152

31

32

9

464

Yield (pounds)

Bone-free meat
Total

31,700

65,700

69,850

12,650

11,350

3,300

194,

,550

Average per animal

406.4

405.6

459.5

40 8. 1

354.7

366.

7

419.

3

Liver
Total

3,000

6,500

6,150

1,100

1,050

300

18,

, 100

Average per animal

38.5

40.1

40.5

35.5

33.9

44.

4

39.

0

Man hours expended in obtain-
ing and processing animals
Total

782

861

689

176

168

70

2,

746

Average per animal

10.2

5.3

5. 7

5.3

5.9

Processing

Hunting was usually discontinued
aifter approximately eight animals had
been retrieved. The hunting party then
returned to the Arctic Maid to unload
the animals. Usually two trips were
made to the rookeries each day.

The aniinals were hoisted aboard
the Arctic Maid with the cargo winches.
They were placed at two work areas
on the forward and after decks over
the brine tanks. Here they were pre-
pared for skinning. First, the fore-
flippers were removed. Then the hide
was split dorsally and ventrally and
peeled back from the neck (fig. 4). The
inner surface of the upper for^flipper
was split to prevent binding during

skinning. The carcass was then reslung
on the winch and lowered to the main
deck where skinning was completed.

Skinning was accomplished by pull-
ing the carcass away from the hide.
Hooks fastened to the main deck were
attached to one side of the hide at the
neckline. The carcass was then lifted
by the winch, thus pulling it from the
hide (fig. 5). The same operation was
repeated to remove the other side of
the hide. Most of the blubber came off
with the hide, and the remainder was
trimmed off with knives.

As soon as skinning was com-
pleted, the liver and the shoulders
were removed. Next, the meat was
trimmed from the carcass. This was

Figure 4. — Sea lion prepared for skinning.

Figure 5.- -Deck hooks inserted into hide at neckline allow
ship's gear to pull carcass away from hide.

done, starting from the neck, by cutting
around the carcass as close to the
bone as possible down the length of the
carcass (fig. 6). This resulted in a
blanket of bone-free meat. After
flensing, the carcass was dropped over-
board (fig. 7). The meat, along with
the shoulders and livers, was placed
on the deck of the ship to cool over-
night.

The internal temperature of the
sea lions at the time they were proc-
essed ranged from 99° to 102° F. Since
the night air temperature averaged
46° F, the meat was cooled to between
50° and 60° F.

On the morning after the butcher-
ing, the shoulders were boned and all
of the meat was ground in a 15 -hp.
grinder through a 3/4 -inch plate (fig.
8). The ground meat was carried by
an auger-type conveyor into a hopper.
From the hopper the meat was passed
through an adjustable door into poly-
ethylene bags (fig. 9). The bags were
rested on a scale and each one was
filled to 50 pounds. A wood frame was
used on the scale to keep the bags
from tipping during filling. The bags
were fastened shut with wire staples.
The livers were packaged in the same
manner, except that they were not

Figure 6.--Trimiiung meat from sea lion carcass.

ground but were packaged whole or in
large pieces.

The bags of meat and liver were
laid out individually on the freezer hold
deck to freeze before being stacked for
storage (fig. 10). Temperature of the
meat at the time it went into cold storage
was between 50° and 55° F. Hold tem-
peratures were usually maintained at
0° to 5° F. but, on some occasions,
temperature reached as high as 10° F.
for periods of as long as a day. It was
found that 10 to 20 hours were required
to bring the temperature of the bags of

Figure 7,--Carcass, after flensing, ready to be
dropped overboard.

meat to 30° F. and approximately 3
days to completely freeze them.

The average yield of meat per
animal was 419 pounds and the average
yield of liver was 39 pounds (table 1).
However, the average weight of 84
whole livers that were weighed indi-
vidually was 48 pounds. The liver
weights ranged from 15 to 80 pounds.
Frequently during butchering only part
of the liver was recovered. This ac-
counts for the difference in the yield
of 39 pounds of liver per animal and
the average of 48 pounds for the livers
weighed individually. Also, blood
drained from the livers while they
were being cooled caused additional
weight loss.

Figure 8.- -Grinder for sea lion meat.

Figure 9. — Crew members packaging ground sea lion meat.

Figure 10.- -Bags of sea lion meat in hold for freezing.

Early in the season it was fovind
that two to three times as much meat
could be obtained from male sea lions
as from females for about the same
expenditure of time. As a result, far
more males than females were killed,
452 males and only 12 females being
ultimately processed.

Hides were saved and frozen on
two occasions. The raw hides were
generally poor in quality because of
wounds and scars from fighting. Only
20 hides (40 sections) were saved.
Four whole skinned carcasses were
also saved and frozen.

Proximate Analysis of Ground Sea
Lion Meat

Samples of ground sea lion meat
were collected at various times and
placed in cold storage for later use
in determining the proximate analysis
of the meat. The samples were col-
lected during the packaging operations
by taking small amounts of the ground
meat at random as it passed from the
hopper into the polyethylene bags used

for packaging. Three 5 -pound samples
were collected whenever sampling was
done.

The proximate analyses were com-
pleted by the Ketchikan Technological
Laboratory, Bureau of Commercial
Fisheries, Ketchikan, Alaska. Dupli-
cate determinations were made of each
5 -pound sample.

The results of the analyses are
presented in table 2. The ground sea
lion meat was quite uniform in com-
position. The moisture content of the
meat ranged from 71.6 to 75.5 percent
and averaged 73.6 percent. The oil
content ranged from 3.4 to 7.7 per-
cent and averaged 5.0 percent. The
protein content ranged from 18.4 to
21.8 percent and averaged 20.4 percent.
The ash content ranged from 1.0 to
1.3 percent and averaged 1.1 percent.
These values do not include the sample
taken on June 11, as it was composed
of shoulder meat only. The shoulders
were removed from animals killed on
June 7 and 8. They were held in re-
frigerated sea water at 32° F. until

10

Table 2. -- Proximate composition (in percent) of ground sea lion meat determined by
the method used by the Association of Official Agricultural Chennists

Date and location Number of

Moisture

Oil

Protein

Ash

of sample

animals-

Marmot Island

June 6

10

8

12

10

10

11

2/27

Atkins Island

June 13

10

14

16

15

9

18

13

19

18

20

12

Range

Av.

Range

Av.

Range

Av.

Range

Av.

74.1-74.7 74.4 4.5-4.8 4.6 19.7-20.4 20.1 1.2-1.2 1.2

73.4-74.5 74.1 3.7-4.8 4.1 20.7-21.4 21.1 1.1-1.2 1.1

71.7-72.9 72.4 4.9-6.9 5.8 20.7-21.6 21.1 1.1-1.2 1.2

75.8-77,5 76.8 2.4-4.6 3.2 18.2-18.9 18.6 1.6-1.7 1.6

71.6-74.0 72.6 4.9-7.7 6.3 19.3-21.4 20.4 1.1-1.2 1.1

74.3-75.5 74.8 4.0-5.1 4.5 20.1-20.6 20.3 1.2-1.3 1.2

72.3-74.7 73.8 4.0-7.1 5.7 18.4-19.9 19.0 1.0-1.1 1.0

73.6-74.6 73.9 3.9-4.8 4.3 20.3-21.8 20.9 1,1-1.2 1.2

73.4-74.7 74.0 3.4-5.4 4.4 20.8-21.7 21.1 1.1-1.2 1.1

73.0-74.5 73.8 4.5-5.4 4.9 19.4-20.3 19.8 1.1-1.2 1,2

l_l Indicates the number of carcasses being processed at the time the sample was taken. The meat
from all of these was combined during processing.

2/ Shoulder meat only. The shoulders were removed from 12 carcasses on June 7 and from 15 carcasses

on June 8, and were held in refrigerated sea water at 32° F. until June 11. Then the meat was
trimmed from the shoulders, ground, and packaged.

June 1 1 when the meat was trimmed
off, ground, and packaged. The higher
moisture content of this meat com-
pared with the other samples in table 2
indicates that water was picked up by
the meat during the immersion in sea
water. The high ash content indicates
that salt was absorbed from the sea
water.

Disposition of Sea Lion Meat

With the exception of a small por-
tion retained for experimental pur-
poses, all the sea lion meat and liver
packaged was sold to fur farmers in
the Pacific Northwest for use as mink
food. The frozen, ground meat was sold
through a commercial distributor for
10 cents a pound; livers 12 cents.
Three frozen carcasses were sold for 7
cents a pound.

The meat might also be marketed
for use in zoos, as pet foods, and per-
haps in fish culture. These uses would
be dependent upon tests for nutritional

value and palatability and an assured
stable supply of the raw product.

DISCUSSION

Surveys conducted by the Fish-
eries Research Institute and the Alaska
Department of Fish and Game indicate
that the numbers of sea lions in Alas-
kan waters are great enough to support
a commercial operation. The Arctic
Maid expedition experienced no diffi-
culty in killing, in retrieving animals
from the beach, or in transporting
them to the mothership. From the
standpoint of availability of the raw
product, and providing that facilities
for processing can be improved, the
potential for a commercial operation
is high.

The production of sea lion meat
by the Arctic Maid expedition was
limited by processing problems. The
major limiting factor was butchering.
The large size of the carcasses made

11

it necessary to handle them with the
ship's cargo winches. Therefore, only
two carcasses could be butchered at
any one time. Skinning was not diffi-
cult once the method was developed and
the crew had become experienced.
Trimming the meat from the car-
casses, particularly the shoulders, re-
quired more time than any other phase
of the operation.

Any future attempt at harvesting
sea lions should make use of special-
ized equipment to reduce the amount
of labor required to process the car-
casses. Some method of handling more
than two carcasses at once would be
needed. This could be done by using
an overhead conveyor from which a
number of carcasses could be sus-
pended. It would be difficult to elimi-
nate hand trimming to remove the
meat from the carcasses and shoulders,
but the use of time-saving devices
such as conveyors would allow more
time for trimming.

The method used to cool meat
aboard the Arctic Maid would not be
satisfactory for a larger operation.
First, spreading meat on the deck to
cool would not be practical because
space would be insufficient. Second,
to cool the meat by spreading it on the
ship's deck, it was necessary to leave
it on the deck over night. An alter-
nate method of chilling was tried in
which carcasses were allowed to hang
in the water from the gunwale of the
ship. This method was abandoned be-
cause the fat absorbed water and
formed a sticky jell which nnade trim-
ming difficult.

Considerable time could be saved
if meat were cooled in a tank of cir-
culating sea water, or ground warm
and cooled in a hopper containing a
series of vertical refrigerated plates.
In either case, the meat could be
dropped on a conveyor belt by the
butchers and conveyed to a chilling
tank or to the grinder.

The 15-hp. grinder used on the
Arctic Maid was satisfactory for grind-
ing meat only. It was capable of grind-
ing much larger volumes than the 2 to

3 tons per day produced by the experi-
mental harvest. If bones were to be
included, a larger grinder would be
needed.

The polyethylene bags used to
package the ground meat were satis-
factory for handling prior to freezing,
but they tore easily when the frozen
meat was handled. This permitted air
to circulate freely around the nneat
causing some dehydration and oxida-
tion. Double -wall paper bags with the
inner surface coated with polyethylene
were also tried. These bags tore easily
during handling prior to freezing,
especially if the outside of the bag
became wet. A sturdier bag would be
desirable in any future sea lion proc-
essing operation. There are a number
of bags available, such as a burlap-
polyethylene combination or a multi-
wall water-resistant paper bag con-
taining one asphalt paper layer.

Staples which were used to close
most of the bags of meat were ineffi-
cient because of the time required to
hand staple each bag with five or six
staples. An unsuccessful attempt was
made to use a heat sealing machine to
seal the polyethylene bags. The ma-
chine usually overheated the thin poly-
ethylene, causing it to shrink con-
siderably in some areas , while in others
it did not seal at all. A machine for
stapling or sewing the bags would save
considerable time. With the water-
resistant multiwall or the burlap-
polyethylene bags, machine attached
wire ties could be used.

The rate of freezing the 50-pound
bags of ground meat aboard the Arctic
Maid was slow. Approximately 3 days
were required to freeze them com-
pletely. Any future operation would
require a blast freezer or a plate
freezer for quick freezing the meat.

The yield of meat per animal was
low because a considerable amount of
meat was left on the discarded car-
cass. Under the circumstances this
waste was unavoidable. The amount of
time required to trim all of the meat
from the backbone and between the
ribs was too great to justify doing so.

12

The yield would have been increased
considerably if the rib cage could have
been ground along with the meat. In
addition, the heart, lungs, kidneys, and
spleen could have been included with
the meat. These organs alone would
have increased the yield per animal
by approximately 50 pounds.

Sea lion liver has little value as a
source of vitamin A. Analysis of core
samples taken from 30 bags of frozen
livers showed the vitamin A content to
be 13,550 units per gram of oil or
249,500 units per pound of liver. ' The
livers are satisfactory for mink ra-
tions.

The hides are of little value
because of: (l) scars and bruises the
animals incur naturally and during
handling; (2) cost of curing which
ranges between 30 and 35 cents per
square foot; and (3) poor appearance
of the grain, which precludes com-
mercial acceptance.^ Perhaps a portion
of the hide could be used by the sou-
venir industry in Alaska. For instance,
the leather from the flippers might be
used for items such as billfolds, and
teeth could be used for making souve-
nirs.

The portion of the carcass remain-
ing after the meat has been trimmed
off, including the blubber, could be
used for meal and oil.

There are other factors, aside
from technological or econonnical con-
siderations that might affect the suc-
cess of future expeditions. Sea lions
habitually choose remote and relatively
inaccessible islands as rookery sites.
The great majority of Alaska's rook-
eries are located in the waters of the
North Pacific, an area of frequent
stomas. Stormy weather and its sec-
ondary effect of surf might cause the
loss of many days' operations . Weather
conditions along the Alaska Peninsula

'Analysis completed by a commercial testing labora-
tory,

^Personal communication between Albert D. Levy,
Washington Fish and Oyster Company of California, and
Poetch and Peterson, San Francisco, California.

and the Aleutian Chain were excep-
tionally good during the spring and
early summer of 1959 and did not
seriously hamper the Arctic Maid;
even so, 9 days were lost during her
2 -month cruise because of weather.
However, weather is always an over-
lying risk in any deep-sea fishing
operation and must be considered a
normal hazard.

The cunnulative effects of harvest-
ing sea lion herds are, of course,
unknown. If harvesting continues on an
annual basis, it is certain to produce
lasting changes in herd structure,
abundance, and perhaps distribution.
Studies carried out by the Alaska
Department of Fish and Game and the
Fisheries Research Institute have pro-
vided excellent information on present
distribution and abundance. Informa-
tion on behavior, reproduction, and
other phases of life history has been
obtained, but is based on only a few
observations and specimens.

Seasonal shifts in abundance do
occur. The greatest nunnbers of ani-
mals are found on the rookeries during
the pupping and breeding seasons, mid-
May through mid- July (Mathisen, 1958).
Continued harassment at this time
may force emigration from established
rookeries to even more remote and
inaccessible sites. Movement out of
hunted areas, laterally along the beach
or to nearby rocks, was observed on
all rookeries during the course of the
experimental harvest after 3 to 5 days'
hunting.

The Arctic Mairf harvest consisted
almost entirely of males, because their
large size made them connmercially
more attractive than the smaller fe-
males. Cropping only males will not
affect herd productivity for a number
of years or as long as there is a sur-
plus of breeding males. This is in-
herent in the social structure of sea
lion herds. Breeding bulls maintain
loosely organized harems. Mathisen
(1958) states that the size of an indi-
vidual harem does not remain fixed; a
bull noted to have 30 cows one day
might have 10 the next day and pos-
sibly 35 the third day. Simiilarly, the

13

number of idle bulls is a changing
figure. Since harem bulls that are
killed are quickly replaced by idle
bulls, a great number of bulls would
have to be removed before the produc-
tion of a herd would be affected. Con-
trolling sea lion numbers or reducing
a herd size by cropping only males
would be a slow process. There would
be no sharp decrease in sea lion ac-
tivities on the fishing grounds. If reduc-
tion of the numbers of sea lions is an
urgent and overriding consideration,
then more females must be killed. If
sea lions can be successfully exploited,
it may later become necessary to
regulate the harvest to preserve the
resource.

Sea lion harvesting should take
place during the pupping and breeding
season when the animals are most
available and least wary. On large
rookeries specific areas should be
hunted alternately for a greater yield.
On a hunt-rest basis animals would
not vacate an area quickly and would
therefore be available for a long period
of time.

If utilization of sea lion herds
should prove a commercial success,
the situation will be unique in having
information available for management
during the initial stages of exploita-
tion. Observations of herd structure,
behavior, and life history should con-
tinue and be concomitant with com-
mercial developrment of this resource.

The problems encountered by the
sea lion expedition were numerous.
One of the main objectives was accom-
plished when it was found that sea
lions could be taken in sufficient num-
bers to make a harvest possible. Proc-
essing problems kept production down,
but the use of specialized equipment
would overconne these.

The Arctic Maid harvested sea
lions from five rookeries in the North
Pacific Ocean between Kodiak Island
and Unimak Pass in the period from
May 27 to July 15, 1959- During the
expedition 6 16 sea lions were killed,
of which 464 were ultimately processed.
The yield was approximately 200 tons
of ground sea lion meat and 9 tons of
whole livers. The sea lion products
were frozen and packaged in 50-pound
bags. With the exception of a small
portion retained for experimental pur-
poses, the entire amount of meat and
livers was distributed and sold through
commercial channels to fur farmers
for use in mink rations. The meat was
sold at the rate of 10 cents a pound,
the livers at 12 cents a pound. Pos-
sibilities for other markets exist, but
these are dependent on a stable annual
harvest.

It is strongly advised that anyone
interested in engaging in a sea lion
fishery in Alaskan waters check with
Federal and AlaskanState fishery regu-
lations.

SUMMARY

LITERATURE CITED

A commercial fishing connpany,
under contract with the Bureau of Com-
mercial Fisheries, conducted an ex-
perinnental harvest of Steller sea lions
in Alaskan waters. The purpose of the
experiment was to determine whether
sea lions could be harvested, proc-
essed, and marketed in sufficient quan-
tity to make a commercial venture
practical as a means of decreasing
the size of sea lion herds.

ALASKA DEPARTMENT OF FISH AND
GAME.

1957. Alaska Department of Fish
and Game Annual Report for
1957. 124 pp.

DASSOW, JOHN A.

1956. Utilization of sea lions in
Alaska. U. S. Fish and Wildlife
Service, Commercial Fisheries
Review, vol. 18, no. 1, pp. 5-9.

14

KENYON, KARL W., AND VICTOR B.

SCHEFFER.

1953. The seals, sea lions, and sea
otter of the Pacific coast. U. S.
Fish and Wildlife Service, Wild-
life Leaflet 344, 28 pp.

KYTE, ROBERT M.

1956. Technological studies on the
processing of sea lions. U. S.
Fish and Wildlife Service, Com-
mercial Fisheries Review, vol.
18, no. 6, pp. 1-7.

MATHISEN, OLE A.

1958. Sea lion studies in Alaska.
Transactions, 24th North Ameri-
can Wildlife Conference, pp.
346-356.

PIKE, GORDON C.

1958. Food of the northern sea lion.
Fisheries Research Board of
Canada, Biological Station,
Nanaimo, B. C, Progress Re-
port 112, pp. 18-20.

MS #1006

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