Upper Missouri Headwaters fluvial arctic grayling : reintroduction plan

UPPER MISSOURI HEADWATERS FLUVIAL ARCTIC GRAYLING

REINTRODUCTION PLAN

Prepared By
James Magee

STATE DOCUMENTS COLLECTION

JAN 1 [ 2001

Montana state library

1515 E. 6th AVE.
HELENA, MONTANA 59620

For

Montana Fish, Wildlife, and Parks
and

the Fluvial Arctic Grayling Workgroup

June 2000

LIBRARY

3 0864 0016 3360 4

INTRODUCTION

Arctic grayling (Thymallus arcticus) were once widespread in
the Missouri River drainage upstream of Great Falls. Grayling
were endemic to the Missouri River and its tributaries: the
Smith, Sun, Teton, Madison, Gallatin, Jefferson, Beaverhead, and
Big Hole rivers. During the 2 0th century, the range of fluvial,
or river-dwelling, grayling became restricted to the Big Hole
River, about 4% of its native range (Kaya 1992a) . The impacts of
climatic change, introductions of non-native fishes, habitat
alteration, and over-harvest by anglers are considered primary
reasons for the decline of fluvial grayling (Vincent 1962, Kaya
1992a) .

The Big Hole River grayling population declined in abundance
through the mid-1980' s to low levels. Concern for the population
resulted in formation of the interagency Fluvial Arctic Grayling
Workgroup (FGW) to coordinate restoration of fluvial grayling in
the Big Hole River and throughout native range in Montana. A
plan was developed to recover Arctic grayling with a goal of "at
least five stable, viable populations distributed among at least
three of the major river drainages. . .within the historic range of
Montana grayling... (FGW 1995)."

The upper Ruby River above Ruby Reservoir, and South and
North forks of the Sun River above Gibson Reservoir, were
identified by Kaya (1992b) as a candidate sites for reintroducing
grayling. These streams were of particular interest because they

1

provide a relatively long unimpeded river reaches, a basic
requirement of fluvial grayling habitat. Over 40 miles of the
Ruby River upstream of the reservoir, 13 miles in the South fork
and 21 miles of the North fork of the Sun River may encompass
suitable habitat for fluvial grayling with respect to pool
habitats, adequate flow, temperature, and geomorphology .
Reintroduction efforts on the Ruby River have been on-going since
1997 and were initiated on the South and North Fork of the Sun
River in June and July 1999. In July 1998, the FGW supported
three additional reintroduction sites: 1) the Missouri River
Headwaters near Three Forks, 2) the upper Madison River, and 3)
the lower Beaverhead River. Reintroduction efforts on the
Beaverhead River were initiated in July 1999 when 16,000 yearling
were planted between Twin Bridges and Dillon. Madison River
efforts will be forestalled until on-going research on whirling
disease, rainbow trout, and Tubifex life histories can be
completed.

Missouri River Headwaters

The reintroduction reach encompasses 73 river miles
including; the Missouri River from Toston Dam to its headwaters
at Three Forks (22 miles) , the Gallatin River from its mouth to
the confluence with the East Gallatin River (12 miles) , the
Madison River from its mouth to the Greycliff Fishing Access site
(21 Miles) , and the Jefferson River from its mouth to the
confluence with Willow Creek (18 miles) (Figure 1) . For

2

simplicity, the entire restoration reach described above will be
referred to as the Missouri River Headwaters in this document.
This area is of particular interest because it provides
relatively long unimpeded river reaches, and may encompass
suitable habitat for fluvial grayling with respect to pool
habitats, adeguate spawning substrate, geomorphology , and low
numbers of potentially competing trout. This document is the
Reintroduction Plan reguired for fluvial Arctic grayling
reintroductions in the Montana Fluvial Arctic Grayling
Restoration Plan (FGW 1995) , and by the Memorandum of Agreement
between Montana Fish, Wildlife, and Parks and the U.S. Fish and
Wildlife Service in February 1996.

Restoration Goals, Objectives, and Scope

The restoration goal is to reintroduce fluvial Arctic
grayling into the Missouri River Headwaters beginning in 2000,
and to establish a stable, naturally reproducing population by
2 007. Objectives of the reintroduction are to:

1) Establish a self-sustaining fluvial grayling population in
the Missouri Headwaters,

2) Monitor survival, movements and densities of introduced
grayling to determine factors affecting success of
reintroduction ,

3) Through monitoring, document natural reproduction by 2 005,
and,

4) Attain stable to increasing population densities in sampling

3

sections where natural reproduction equals or exceeds annual
mortality for three consecutive years.

It is recognized that the success of any reintroduction will
hinge upon a complex set of environmental variables beyond the
control of resource managers. Thus, it is important to define
the scope of time that will be dedicated to the effort. If
limiting factors are identified, but cannot be remediated, that
will realistically preclude founding of a self-sustaining
population, the project will cease. Therefore, if natural
reproduction is not documented by October, 2 007 and data do not
demonstrate a likelihood of correcting limiting factors, the
project will be discontinued and resources will be diverted to
alternative reintroduction sites.

IDENTIFICATION OF ISSUES AND SUITABILITY FOR GRAYLING

A number of issues must be addressed to successfully plan
and implement the reintroduction program. Issues were identified
by representatives of the FGW, Montana Fish, Wildlife, & Parks
(MFWP) , and interested publics through written comments and at
open meetings held in Ennis, Three Forks, and Twin Bridges, in
April 1999, and at additional meetings in Ennis and Twin Bridges
in June 1999. These issues are summarized in an Environmental
Assessment and Decision Notice issued by Montana Fish Wildlife
and Parks, July 1999.

4

Endangered Species Act

The U. S. Fish and Wildlife Service (USFWS) formerly
classified fluvial Arctic grayling in Montana as "Category 1"
under the Endangered Species Act; that is, enough substantial
information exists to support a proposal to list it as threatened
or endangered (USFWS 1991) . This category was renamed
"Candidate" in February 1996 (USFWS 1996) , and fluvial Arctic
grayling currently remain classified as a Candidate species. A
petition to list fluvial Arctic grayling as endangered was
submitted in October, 1991 (USFWS 1993) . A recent finding on the
petition recommended that listing fluvial Arctic grayling was
"warranted, but precluded" by higher priority listing actions
(USFWS 1994) .

The potential for listing fluvial Arctic grayling as
endangered is a primary concern of the some residents of the
proposed sites. Reintroduction of a candidate species to the
proposed sites is perceived to potentially affect fisheries and
land management on public and private lands. However, a recent
agreement between USFWS and MFWP may alleviate many of the
concerns as to the affects of a potential listing.

A Memorandum of Agreement was developed to maintain efforts
to protect and restore fluvial grayling in the Big Hole River
while expanding the program to reestablish additional
populations. This agreement, signed in February 199 6, includes a
provision that, "By December 31, 2000, a minimum of four
. . . reintroductions will be in progress ... within the historic

5

range (MFWP Files)." This re introduction effort will help to
fulfill this requirement, along with other on-going
reintroductions . The goal of the Agreement is to restore fluvial
grayling to a level such that listing under the Endangered
Species Act is not warranted. Progress toward establishment of a
viable population of fluvial grayling in the proposed sites would
be an important step toward fulfilling the terms of the
agreement, achieving grayling restoration, and precluding the
need to list. In the event that terms of the agreement are not
met, a status review will be initiated in 2002 to re-determine
the necessity of listing.

Private Property

The majority of the reintroduction reach flows through
private land. These lands are primarily undeveloped agricultural
lands used for pasture and irrigated hay production. Diversions
for irrigated hay and pasture lands are substantial for all
systems, and total 555,4 00 acres upstream from USGS gaging
station at Toston (USGS 1998) . Concerns were voiced that
reintroducing grayling may impact private lands management. The
primary concerns, relating to the Endangered Species Act, are
addressed above. No additional legal protection would be
provided to grayling, other than angling regulations. Statutes
protecting grayling and their habitat in the designated upper
Missouri River Headwaters reach would include laws already in
effect, regardless of presence or absence of grayling. For

instance, the Montana Stream Protection Act (12 4) and Montana
Natural Streambed and Land Preservation Act (310) require permits
to alter streambeds and banks. Water rights granted under the
Montana Water Use Act would be unaffected by the introduction of
grayling. Entrainment of grayling into legally permitted
irrigation canals could only be prevented via voluntary
corrective measures. If corrective measures are necessary,
financing would be sought to avoid imposing financial burdens on
landowners. Thus, private land management rights would remain
unchanged with respect to a grayling reintroduction .

Public Lands Management

Public lands in the Missouri River Headwaters
restoration reach are limited to widely dispersed sections of
State and Bureau of Land Management (BLM) properties. State
Fishing Access sites (FAS) include Greycliff and Cobblestone Cove
on the Madison River, Gallatin Forks at the confluence of the
East and West Gallatin Rivers, Missouri River Headwaters State
Park at the confluence of the three tributaries and Fairweather
State FAS on the mainstem Missouri (Figure 1) . The potential
effects of introducing grayling into these drainages would be
minimal and regulations for the existing fishing access would
pertain to current laws (Stream Access and private property
laws) . No regulatory changes for fishing access sites on State
or BLM lands would be required. Fishing regulations will remain
catch and release for grayling.

7

Other possible land management activities that may be
impacted would include road maintenance. As stated in the
section above on private lands, existing statutes protecting
streambeds and banks would remain unchanged in the presence of
Arctic grayling.

Fisheries Management

The reintroduction reach supports wild, resident game fish
populations of rainbow trout, brown trout, and mountain
whitefish. Resident non-game species include mottled sculpin,
longnose dace, longnose and white suckers, and carp. Other
species that have been documented but are rare include cutthroat
trout, flathead chub, golden shiner, stonecat, yellow perch,
black crappie, largemouth bass, and brook trout. The headwaters
area supports few angler days relative to stream miles. In 1997,
angler pressure for the lower Gallatin (Mouth-East Gallatin)
ranked 20th in the region with an estimated at 7,494 (SE=1031)
angler days and the Missouri River between Toston and Three Forks
ranked 56th in the region at 956 (SE = 481) . Estimates for the
specific reaches of the Madison and Jefferson Rivers encompassed
in the restoration reach are not available, but are most likely
fairly low due to low densities of sportfish and more popular
upstream reaches (MFWP 1998) .

Game fish populations have recently been monitored by
electrof ishing surveys in the lower Madison, lower Gallatin,
lower Jefferson, and Missouri River Headwaters reaches. Survey

8

reaches include the Greycliff Section on the Madison, the Logan
Section on the Gallatin, the Trident Section on the Missouri, and
the Willow Creek Section on the Jefferson (Figure 1) . Densities
of rainbow and brown trout in these areas are relatively low
(200-600 fish per mile) compared to productive upstream
reaches (Table 1). Rainbow trout recruitment may be limited by
quality of spawning and rearing tributaries, while brown trout
(primarily a mainstem spawner) recruitment may be more associated
with flow regimes (Ron Spoon, MFWP Fisheries Biologist, Personal
Communication) . Other factors that may be limiting trout
densities include high temperature regimes, riparian
degradation, sedimentation and whirling disease.

Kaya (1992b) expressed concern that the presence of non-
native fishes in Missouri Headwaters may hinder success of
reintroduction efforts. Arctic grayling are an aggressive fish
that have been observed to successfully defend territories
against similar-sized rainbow and brown trout in low densities
(MFWP Files) . In lower reaches of the Big Hole River, grayling
at low densities (15-30 age 1+ per mile) co-exist with rainbow
and brown trout at high densities (1,500-2,000 age 1+ per mile).
Densities of grayling are highest (50-100 age 1+ fish per mile)
in the upper reaches where brown and rainbow trout densities are
low (<50 age 2+ per mile) . Grayling in Deep Creek, a tributary
of the Big Hole River, and in the Sportsmans to EastBank Section
of the Big Hole River co-exist successfully at approximately 50
age 1+ grayling per mile with rainbow trout densities exceeding

9

200 age 2+ per mile. Established resident species may influence
survival of stocked grayling through predation and competition
for food and space. Thus far, grayling planted in the Ruby River
have had no negative effects on rainbow\cutthroat trout
population densities or condition factors (Opitz 2000) . The
affects of resident populations and stocked grayling on each
other will be monitored.

10

▲ Thermograph Site
+ Fishing Access Site (FAS)
-» MFWP Electrof ishing Section
O USGS Gaging Station

M.i ssouri River
Headwaters
FAS

v. Toslon
* Dam

£ \ + Fairweather FAS
^ MONTANA

Trident
Section

Aim

Gallatin Forks FAS
/

Three Forks
Section

Greyclif f
• section

+

Greyclirr
FAS

Sal* \:Wm

Fiqure 1. Map of Missouri River Headwaters Restoration Reach

including Fishing Access Sites (FAS) and Montana Fish,
Wildlife and Parks electrof ishing sections, USGS
gages and thermograph sites.

11

Table 1. Estimated densities of age 2 and older rainbow (RB) ,
and brown trout (LL) from Montana Fish Wildlife and
Parks electrof ishing sampling sections in the lower
Madison, lower Gallatin, and the mainstem Missouri
downstream from Three Forks, Montana. Estimates for
brown trout on the Three Forks section are age 3 and
older. Estimates could not be made for rainbow trout in
the Three Forks Section.

QatnTil "i Tin

Section

Miles

River

Year

Abundance
RB(#/mi)

Abundance
LL(#/mi)

GreyClif f

3 . 2

Madison

1989

530

1665

1990

194

1098

1992

1214

1088

1994

393

709

1995

388

508

Logan

4 . 0

Gallatin

1999

350

355

2000

321

377

Trident

5.0

Missouri

1981

219

256

Three Forks

7 . 0

Jefferson

1986

na

346

1988

na

362

1998

na

160

1999

na

200

Angling regulations in the restoration reach will not be
changed following the reintroduction of grayling unless
biologically justified. Currently, grayling are managed under
catch-and-release-only regulations in Montana streams. Daily bag
limits for trout in the restoration reach are 5 daily and in
possession except for the Jefferson River which is catch-and-
release-only for rainbow trout, and 5 brown trout with only one
over 18 inches. All of the encompassed reach is open year round
to angling. If research and monitoring identifies predation, or

12

competition, from non-native species as a factor limiting
grayling survival, MFWP biologists will review data, and identify
options to formulate management recommendations.

Grayling may migrate into upstream tributary reaches or
downstream in the Missouri River. While grayling will be
protected under catch-and-release regulations, no further
regulatory measures for grayling will be exerted in these
reaches. Access to these other reaches may provide grayling with
additional necessary habitats to sustain a viable population.

Whirling Disease

Presence of the myxosporean parasite Myxobolus cerebralis
and symptoms consistent with whirling disease has been documented
in the Madison, Gallatin, Jefferson and the mainstem Missouri
River (Vincent 2000). In 1999, numerous sentinel cages were used
to determine the presence or absence, the degree of whirling
disease infection, and to determine likely sites where whirling
disease may have population impacts. Sites within, or in nearby
upstream reaches include two sites in the East Gallatin, one in
the mainstem Gallatin at Logan, one at the mouth of Madison
River, five sites on the Jefferson and one site at the mainstem
Missouri near Toston (Vincent 2000) . All sites on the East
Gallatin, Mainstem Gallatin and Jefferson tested whirling disease
positive with low to moderate intensity levels. Whirling disease
has not been detected at the mouth of the Madison River, and
results were inconclusive at Toston. However, many of the sites

13

were tested in fall months and it is premature to conclude that
whirling disease infection rates are benign. In fact,
deformities indicative of whirling disease have been detected in
each headwater reach. Distribution of the intermediate host,
Tubifex tubifex worms, are unknown in the restoration reach.
However, habitats of cold, nutrient-rich water, necessary for
Tubifex proliferation are present. Hence, the potential for
proliferation of the parasite exists in the restoration reach and
upstream mainstem and tributary systems.

While rainbow trout densities have severely declined in
the upper Madison, research on the effect of whirling disease in
the restoration reach are on-going. Brown trout can be a carrier
of the myxosporean parasite, and are not immune to whirling
disease (Opitz 1999) . However, whirling disease has generally
had minimal effects on brown trout populations (Dick Vincent,
MFWP, Personal Communication) . Populations of brown trout have
remained at low levels in the restoration reach, and are more
likely limited by flow and habitat conditions. Whirling disease
susceptibility tests at University of California at Davis and two
field experiments in Montana strongly support the contention that
grayling are highly resistant to whirling disease infection.
There is no evidence to suggest that whirling disease will
negatively affect grayling in a whirling disease positive
environment, and in fact, may benefit grayling by decreasing
interspecific competition with infected trout populations.

14

Habitat and Biological Suitability

Gradient in the restoration reach of less than 1% is typical
of historic fluvial grayling habitats, and current Big Hole River
reaches preferred by fluvial Arctic grayling. Flow in the
Jefferson River is partially regulated by Clark Canyon Reservoir
and Ruby Reservoir. Flow in the Madison is partially regulated
by Hebgen Lake and Ennis Lake. The Gallatin River has no
regulating reservoir and the mainstem Missouri has no regulating
dam in the restoration reach. Toston Dam, at the downstream
boundary of the restoration reach, is a barrier to fish movement
and creates a small run-of-the-river irrigation storage
reservoir. All of the systems are modified by irrigation
withdrawal during summer months. Mean monthly discharge data for
each USGS gage (USGS 1890-1998) are summarized in Table 2. The
restoration reach undergoes dewatering during summer months that
may be severe during drought periods. Minimum flows have not
been established for the three tributaries, however, recommended
wetted perimeter (Montana Fish Wildlife & Parks 1989) are
summarized in Table 3. Maintaining wetted perimeter
recommendations may not be feasible during all years, however,
instream flows far below recommended wetted perimeters in summer
months reflect the magnitude of water diversion for agricultural
use .

Impacts of dewatering on grayling during prolonged drought
periods, as documented in the upper Big Hole River, may also
affect grayling in the Missouri River Headwaters. In the Big

15

Hole River, between 1988 and 1995, mean monthly flows ranged from
58.7 to 85.8% of long-term (50-year) average. Arctic grayling
densities in the Big Hole River declined dramatically from 111
age 1+ grayling per mile in 1983 to 22 age 1 + grayling per mile
in 1989. Instream flows improved in mid 1990 's and grayling
densities increased to 96 per mile by 1997 (Magee and Byorth
1998) .

Low flows typically occur in August and are below winter
base flows in the Missouri, Jefferson and Gallatin Rivers (Table
3) . The Madison River is regulated by Ennis Dam 40 miles
upstream from the mouth and does not experience the magnitude of
dewatering as the Gallatin, and Jefferson Rivers. For example,
in the severe drought years of 1988 and 1994, minimum flows in
August were well below historic average and more severe in the
Jefferson River (6.5% and 27% of the mean average in 1988 and
1994, respectively) and the Gallatin Rivers (53% and 66%,
respectively) compared to the Madison (70% and 85%,
respectively) (Table 3). The gage is 40 miles upstream from the
Three Forks confluence and does not reflect irrigation withdrawal
that occurs downstream of the gage.

Peak flows in the Missouri Headwaters restoration reach
typically occur in April, May, and June, (Table 2) and are
somewhat regulated and vary by water year depending on
agricultural demand. Lower and regulated flow levels during
spring months may affect grayling spawning success. Arctic
grayling in the Big Hole River typically spawn in late April or

16

early May between lowland and highland runoff utilizing newly
eroded and cleansed spawning gravels from ice scouring and the
fluvial process. While spawning substrate is available in the
restoration reach and specifically in the active braided
tributary channels, grayling may have to adapt behaviorally to
facilitate natural reproduction.

While the Madison River may not have the magnitude of
dewatering, it may not have the positive attributes of natural
flow regimes and high water events. Specifically, decreased
sediment transport, limited recruitment of riparian and
cottonwood communities, and limited access to the flood plain.
Within the restoration reach, poor riparian development in
upstream tributaries and the mainstem systems have increased bank
instability and sedimentation. Lack of cottonwood and willow
recruitment from limited flood plain access or severely depleted
flow regimes may decrease riparian community recruitment. Poor
grazing practices and channel stabilization projects to protect
floodplain developments have aggravated the instability problem.
Sediment loads (tons per-day) and suspended sediment data is
limited. Single daily measurements at Toston Dam for 1900-1995
are summarized in Table 4. High sediment loads may negatively
affect spawning success by infiltrating spawning substrates with
fine sediments. High sediment loads may also limit aquatic
invertebrates by imbedding substrate and decreasing oxygen flow,
and decreasing food sources for many other aquatic species
including introduced Arctic grayling.

17

Table 2 . Monthly mean discharge (cubic feet per second (cfs) )
at the USGS Jefferson River gage near Three Forks,
Madison River gage below Ennis Lake, Gallatin River
gage at Logan, and Missouri River gage near Toston.

Month

Gage (cfs)

Three
Forks®

Jinnis©

Logan®

1 OSLOiiw

January

1239

1378

690

3368

February

1349

1385

706

3722

March

1620

1440

796

4154

April

2511

1563

1058

5700

May

4107

2019

2160

9030

June

5398

3024

3016

12700

July

2322

1881

1039

5370

August

1029

1546

497

2821

September

1278

1642

654

3499

October

1660

1963

775

4473

November

1678

2029

822

4763

December

1362

1520

749

3779

® Three Forks 2.5 miles Northwest of the town of Three Forks:
1938-1998 .

<D Ennis Lake Near McAllister 1.5 miles downstream of Ennis Lake

1939-1998 .
® Gallatin River at Logan: 1894-1998.

(D Missouri River near Toston: 2.2 miles south east of Toston:
1890-1998.

18

Table 3. Recommended MFWP wetted perimeter flows (CFS) , historic
winter base flows, historic mean August minimum flows,
mean August flows in 1988 and 1994, and percent
of historic August mean flows in two extreme drought
years (1988 and 1994) for tributaries and mainstem
Missouri River.

Reach

WetP

CFS

Winter

Base

Flow

Mean

August

Flow

Mean

August

1988

(Percent)

Mean

August

1994

(Percent)

Jefferson
at Three
Forks

1, 100

1, 180

901

59

(6.5%)

242
(27%)

Gallatin
from Mouth
to E.Gal

1, 000

684

488

257
(53%)

322
(66%)

Madison
Ennis Dam-
Mouth

1, 300

1, 390

1 , 531

1, 068
(70%)

1, 192
(86%)

Missouri
Canyon
Ferry-Three
Forks

2 ,400

3 ,360

2,762

896
(32%)

1,272
(46%)

19

Table 4. Mean monthly sediment loads (tons per day), sediment

concentration (mg/1) , specific conductance (US/CM) and
ranges and discharge from USGS Missouri River at Toston
gaging station for single day measurements in March,
June, August, and November from 1990-1995.

Month

Sediment
Load

Tons/day

Sediment Cone.
(mg/1)

Specific
Conductance

Discharge

March

108 (65-322)

10 (4-25)

383 (362-
407)

3 , 540

(2,920-

4,770)

June

6386 (112-
25,900)

116 (10-378)

269 (213-
314)

11, 702
(4160-
25, 400)

August

102 (27-
320)

13 (11-20)

341 (331-
350)

2513

(1080-

3700)

November

103 (68-
145)

9 (6-15)

386 (343-
423)

4420

(3590-

5690)

Water quality parameters vary between the Missouri River
Headwaters and the Big Hole River. At Toston Dam, USGS data from
water years 1990-1995 reported specific conductances ranging from
213-423, averaging 345 ^mhos/cm and mean pH was 8.4 (USGS 1990-
1995) . Surveys in the upper Big Hole River in August 1993
indicated mean specific conductances of 85.3 |Limhos/cm and mean pH
of 7.6 (MFWP Files). Water chemistry and consequently the
biological productivity in the Missouri River Headwaters may
affect survival of stocked grayling. The limestone geology of
the Missouri River Headwaters releases biologically rich elements
into the river. Further, dams act as nutrient sinks and sources,
concentrating and transferring nutrients downstream to the highly

20

productive tailwaters. However, the tailwater effects are
diluted further downstream and trout abundance is greater
immediately below Clark Canyon, Ruby, and Ennis dams. Chemical
composition of the Missouri River Headwaters may also be affected
by runoff of agricultural fertilizers. Chemical composition of
the Missouri River Headwaters, subsequent biological
productivity, and the effects of sediment loads, bank
instability, and poor riparian development are unknown and may
affect macro-invertebrate productivity. Invertebrate composition
and densities have not been measured in the Missouri River
Headwaters. Effects of sediments on invertebrate populations may
be included in the monitoring protocol of the Missouri River
Headwaters Arctic grayling restoration efforts.

Annual water temperatures recorded in the Missouri River
Headwaters are limited to the USGS Toston gage with some periodic
data from other locations, Table 5. Water temperatures over 21°C
are typically considered stressful to salmonids (Behnke 1991) .
Maximum temperatures surpassed 21°C from 0-14 days in June, 0-26
days in July, 0-31 days in August, from 1990-1998 (USGS 1990-
1998) (Table 5) . Maximum temperatures in 1990-1998 averaged
19.6°C in June, 23.2°C in July, and 24.1°C in August (USGS 1990-
1998) . Thermal tolerance of grayling is exceeded above 25°C
(Lohr et al. 1996). A maximum temperature of 26.5°C occurred in
August 1992 and surpassed the thermal tolerance level for fluvial
Arctic grayling. Temperatures greater than 2 5°C occurred on
numerous days in July and August 1990 and 1992, and can be

21

expected to exceed thermal tolerance levels in drought or
prolonged high temperature regimes. As part of the Madison-
Missouri dam mitigation process, flow release will be increased
from Ennis dam based on specific temperature triggers to reduce
thermal stress and potential fish mortality. During high
temperature regimes the lower Madison fishery, including
introduced Arctic grayling, will benefit from pulsed flow
releases preventing prolonged thermal stress.

Temperatures in some reaches of the upper Big Hole River
exceeded thermal tolerance for Arctic grayling in five of seven
years between 1988-1994, when stream flows were at historic lows,
and again in 1996 and 1998 with higher flows. Arctic grayling in
the Big Hole River have been able to survive, and have increased
in abundance under higher flows regimes with temperatures
exceeding lethal levels between 1995-1998. While temperatures in
the Missouri River Headwaters will surpass 21° C during most
years in July and August and may reach lethal levels, adeguate
flows may provide Arctic grayling the ability to seek refugia in
micro-habitats with cooler temperature regimes (deep pools,
springs) . In prolonged drought periods with decreased flows and
warm water temperatures, thermal stress may negatively effect
grayling and other resident species. Water temperatures will be
monitored at different locations within the proposed reach to
assess thermal regimes (Figure 1.)

22

Table 5. Mean maximum daily temperatures for June, July and
August, and number of days in which temperatures
exceeded 21°c from 1990-1998 at USGS Toston gage
station .

June

July

August

Year

Max

Days>

9 1°
Z X

Max

Days>

9 1°
A ±

Max

Days>

9 1°
A X

1 qqn

_L Zt ZJ \J

9i n
z _L . u

9
A

9 r n
A o . u

9 A

A <i

9 ^ n

A D . U

1 Q Q 1

17 . 5

0

24 . 5

22

24 . 5

31

1992

23 . 0

14

25.0

12

26.5

21

1993

19.5

0

19.0

0

20.5

0

1995

19 . 5

0

21. 5

7

23.0

11

1996

19 . 0

0

23 . 5

26

24 . 5

25

1997

18 . 5

0

23 . 0

12

NA

NA

1998

19 . 0

0

24 . 5

22

24 . 0

24

RE INTRODUCTION AND MONITORING PROTOCOL

Grayling will be stocked into the restoration reach
beginning June 2 000 and continue each year at least through the
year 2002. Yearling (age 1+) and young-of-the-year (<age 1) (YOY)
grayling may be supplied by USFWS Fish Technology Center in
Bozeman or MFWP State Fish Hatcheries with fish descended from
wild fluvial Big Hole River stock. Recommended minimum stocking
rates are densities of 350 grayling per mile or 25,500 yearlings
based on predicted mortality of 75%-90% first year mortality.
Assuming 75% annual mortality approximately 90 survivors per mile
would remain after one year, which is roughly the Big Hole
River's highest density in recent years. Stocking rates will
depend on availability of fish, and may be increased if fish are

23

available. Stocking rates of YOY grayling should be egual to or
greater than those of yearling plants. Grayling will be
transported in aerated tanks to release sites, tempered to river
temperatures and released. A subsample of each lot will be held
in live cars to assess short term survival for 1 to 3 days.
Release site locations will be at the upper, middle, and lower
portions of the reintroduction reach. Yearling grayling should
be released immediately after runoff in late June or early July.
YOY should be stocked in late August (as temperatures decrease)
to maximize growth in the hatchery but allow sufficient
acclimation before winter. Grayling will be clipped every other
year to identify year classes. Planting schedules, stocking
rates, and locations will be determined based on survival,
movement, and information gathered in the monitoring program.

Monitoring

Thorough monitoring of restoration efforts is necessary to
maximize the probability of success and to document factors that
may hinder or help future reintroductions . Monitoring will
continue through 2 007 unless data dictate that successful
establishment of a self-sustaining population is unlikely.

Electrof ishing will be employed as a primary monitoring tool
to document survival, dispersal, population density, and fish
community composition. Electrof ishing sections in the
reintroduction reach will include: Greycliff section on the
Madison, Logan section on the Gallatin, Trident section on the

24

Missouri, and the Three Forks section on the Jefferson.
Additional sections upstream in the Jefferson including the
Waterloo and Hells Canyon Section may document upstream movement.
Each section will be electrof ished in spring to investigate over-
winter survival, maturity, dispersal, and to identify spawning
areas. Fall electrof ishing surveys will document post-plant
survival, dispersal, growth, and condition factor.

Further monitoring investigating limiting factors affecting
the establishment of a self sustaining population may include;
invertebrate surveys and food habits of grayling and sympatric
species using gastric lavage technigues, and predation of
grayling by brown or rainbow trout. Summer distribution surveys
may include hook and line and voluntary creel surveys to assess
dispersal and survival. Habitat and sediment surveys will assess
relationships of habitat usage, availability, and sediment
regimes with survival. Radiotelemetry , coded wire, and visual
implant (VI) tags may be used to individually mark fish to assess
movement and dispersal. Thermographs will be deployed at various
locations to assess temperature regimes and flows will be
monitored at the USGS gaging stations. The extent of additional
research and monitoring projects will depend on funding sources
and workload and may include a graduate study through Montana
State University.

25

CONCLUSIONS

Analysis of social and biological issues indicates that a
reintroduction of grayling into the Missouri River is feasible
and should be pursued. The assistance of local communities in
identifying issues and their support for the reintroduction will
be a key in the success of the program. The few concerns voiced
during public meetings and comment periods were primarily
concerned with the impacts of the Endangered Species Act on
private land management if the grayling were listed. Concerns
regarding this issue should be allayed by the cooperative
agreement between USFWS and MFWP, which will allow the
reintroduction program to continue without the likelihood of
classification of fluvial Arctic grayling as endangered. Much
about the biological suitability of the Missouri River Headwaters
for grayling is unknown. While cursory analysis of habitat,
temperature, flow, and species composition data indicate both
positive and negative attributes, the potential for establishing
a self-sustaining population will best be answered by a well-
planned reintroduction followed by thorough monitoring. Arctic
grayling in the Big Hole River have survived many environmental
changes over the past 100 years, including stream dewatering,
elevated water temperatures, barriers blocking seasonal
migrations, and non-native trout introductions. Progeny from the
surviving Big Hole River stock may offer a better chance to re-
establish populations in modified historic habitats like the
Missouri River Headwaters.

26

The key to conserving Montana's unique stock of fluvial
Arctic grayling is maintaining the Big Hole River population at
maximum stable levels while re-establishing additional
populations throughout its native range. Our goal of
establishing a self-sustaining population in the Missouri River
Headwaters will be an important step in preserving Montana's
fluvial Arctic grayling.

27

LITERATURE CITED

Behnke, R. J. 1991. Temperature Niches. In Trout the Wildlife

Series, ed. J. Stolz and J. Schnell, ppl30-132. Stackhole
Books: Harrisburg, PA.

Kaya, C. M. 1992a. Review of the decline and status of fluvial
Arctic grayling (Thymallus arcticus) , in Montana.
Proceedings of Montana Academy of Sciences 52:43-70.

Kaya, C. M. 1992b. Restoration of fluvial Arctic grayling to
Montana streams: assessment of potential of streams in the
native range, the upper Missouri River drainage above Great
Falls. Prepared for: Montana Chapter of the American
Fisheries Society, Montana Department of Fish, Wildlife, and
Parks, U. S. Fish and Wildlife Service, U. S. Forest
Service .

Lohr, S. C. , P. A. Byorth, C. M. Kaya, and W. P. Dwyer. 1996.

High temperature tolerances of fluvial Arctic grayling and
comparisons with summer water temperatures of the Big Hole
River, Montana. Transactions of the American Fisheries
Society 125:933-939.

Magee, J. P., and P. A. Byorth. 1998. Big Hole River Arctic

Grayling Recovery Project: Annual Monitoring Report 1997.
Submitted to: Fluvial Arctic Grayling Workgroup. Montana
Fish Wildlife & Parks. Bozeman, MT.

Montana Department of Fish, Wildlife, and Parks. 1989.

Application for reservations of water in the Missouri River
basin above Fort Peck dam — Vol. 2 — reservation requests for
waters above Canyon Ferry dam. Montana Department of Fish,
Wildlife, and Parks, Helena, MT. 620 p.

. 1996. Montana statewide angling pressure, 1995. Montana

Fish, Wildlife, and Parks, Bozeman.

. 1998. Montana statewide angling pressure, 1995. Montana

Fish, Wildlife, and Parks, Bozeman.

Montana Fluvial Arctic Grayling Workgroup. 1995. Montana
fluvial arctic grayling restoration plan. Montana Fish,
Wildlife, and Parks, Helena.

Opitz, S. T. 2000. Upper Ruby River Fluvial Arctic Grayling
Reintroduction, Annual Report 1999. Montana Department of
Fish, Wildlife, and Parks, Bozeman.

28

Opitz, S. T. 1999. The Effects of Whirling Disease on Brown

Trout Recruitment in the Ruby River and Poindexter Slough,
MT. Masters Thesis, Montana State University-Bozeman .
Bozeman, MT.

U. S. Fish and Wildlife Service. 1991. Endangered and

threatened wildlife and plants; animal candidate review for
listing as endangered or threatened species, notice of
review. Federal Register 56 (225) : 58804-58836 .

. 1993. Endangered and threatened wildlife and plants; 90-
day finding and commencement of status review for a petition
to list the fluvial population of the Arctic grayling as
endangered. Federal Register 58 (11) : 4975-4976 .

. 1994. Endangered and threatened wildlife and plants;

finding on a petition to list the fluvial population of the
Arctic grayling as endangered. Federal Register
59 (141) : 37738 .

• 1996. Plant and animal notice of review. Federal

Register 61:7596.

U. S. Geological Survey. 1890-1998. Water resources data,

Montana, water year 1890-1998. U. S. Geological Survey
Water-Data Reports. Helena, MT.

Vincent, E. R. 2000. Whirling Disease Report 1997-98. Montana
Department of Fish, Wildlife, and Parks, Bozeman.

Vincent, R. E. 1962. Biogeographical and ecological factors
contributing to the decline of Arctic grayling, Thymallus
arcticus Pallas, in Michigan and Montana. Ph.D. Thesis.
University of Michigan, Ann Arbor.

29