Endangered and Threatened Wildlife and Plants; Proposal to List the Klamath River Population Segment of Bull Trout as an Endangered Species and Columbia River Population Segment of Bull Trout as a Threatened Species

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018--AE29

Endangered and Threatened Wildlife and Plants; Proposal to List

the Klamath River Population Segment of Bull Trout as an Endangered

Species and Columbia River Population Segment of Bull Trout as a

Threatened Species

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The U.S. Fish and Wildlife Service (Service) proposes to list

the Klamath River population segment of bull trout (Salvelinus

confluentus) as endangered from south-central Oregon; and the Columbia

River population segment of bull trout as threatened from the

northwestern United States and British Columbia, Canada, with a special

rule, pursuant to the Endangered Species Act of 1973, as amended (Act).

The Klamath River population segment, comprised of seven bull trout

populations from south-central Oregon, is threatened by habitat

degradation, irrigation diversions, and the presence of non-native

brook trout. The Columbia River population segment, comprised of 386

bull trout populations in Idaho, Montana, Oregon, and Washington with

additional populations in British Columbia, is threatened by habitat

degradation, passage restrictions at dams, and competition from non-

native lake and brook trout. The special rule allows for take of bull

trout within the Columbia River population segment if in accordance

with applicable State fish and wildlife conservation laws and

regulations. Pursuant to a court order, this rule is based on the 1994

administrative record. All available information, including current

data, will be considered prior to promulgation of a final rule. If,

after consideration of all available data, this proposal is made final,

it would extend protection of the Act to these two fish population

segments.

DATES: Comments from all interested parties must be received by August

12, 1997. Public hearings locations and dates are set forth in

SUPPLEMENTARY INFORMATION.

ADDRESSES: Comments and material concerning this proposal should be

sent to the U.S. Fish and Wildlife Service, Snake River Basin Field

Office, 1387 S. Vinnell Way, Room 368, Boise, Idaho 83709. Comments and

material received will be available for public inspection, by

appointment, during normal business hours at the above address.

FOR FURTHER INFORMATION CONTACT: Robert Ruesink, Field Supervisor,

Snake River Basin Field Office (see ADDRESSES section) (telephone 208/

378-5243; facsimile 208/378-5262).

SUPPLEMENTARY INFORMATION: Public hearings locations and dates are:

1. Tuesday, July 1, 1997, from 2:00-4:00 p.m. and 6:00-8:00 p.m.,

Ramada Inn Portland Airport, 6221 N.E. 82nd Avenue, Portland Oregon.

2. Tuesday, July 8 1997, from 2:00-4:00 p.m. and 6:00-8:00 p.m.,

Shilo Inn, 923 East Third Avenue, Spokane, Washington.

3. Thursday, July 10, 1997, from 2:00-4:00 p.m. and 6:00-8:00 p.m.,

Doubletree Hotel Edgewater (formerly Village Red Lion Inn), 100 Madison

Street, Missoula, Montana.

4. Tuesday, July 15, 1997, from 2:00-4:00 p.m. and 6:00-8:00 p.m.,

Shilo Inn, 2500 Almond Street, Klamath Falls, Oregon.

5. Thursday, July 17, 1997, from 2:00-4:00 p.m. and 6:00-8:00 p.m.,

Doubletree Hotel Riverside (formerly Red Lion Hotel), 2900 Chinden

Blvd., Boise, Idaho.

Background

Bull trout (Salvelinus confluentus) were first described by Girard

in 1856 from a specimen collected on the lower Columbia River. Cavender

(1978) presented morphometric, meristic, osteological, and

distributional evidence to document the separation between dolly varden

(Salvelinus malma) and bull trout. Based on this work, taxonomists have

recognized this separation since 1978 (Bond 1992). Bull trout and dolly

varden were officially recognized as separate species by the American

Fisheries Society in 1980 (Pratt 1992).

Although the bull trout is well accepted as a species among

specialists in the evolution and classification of salmonid fishes (R.

Behnke, in litt., 1993), some uncertainty remains regarding the

taxonomic status of bull trout among fisheries managers and industry

(WDW 1992, Platts et al. 1993). When discriminate function values were

used to separate populations of bull trout from dolly varden in the

Puget Sound, a normal distribution resulted rather than a bimodal

curve, which indicated that a clear separation of these species does

not exist (C. Kraemer, in litt. 1993). In addition, Kraemer (in litt.

1992; undated U.S. Forest Service (USFS) survey) observed the two

species spawning together, and suggested introgression may be

occurring. In contrast, Phillips et al. (1992) and Pleyte et al. (1992)

examined evolutionary relationships among six species of Salvelinus

using ribosomal DNA analysis, and found clear distinctions among all

six species. Their results suggested that dolly varden are more closely

related to arctic char than bull trout, and that bull trout

evolutionarily diverged from a line that gave rise to S. leucomaenis (a

char indigenous to Japan) rather than the line that gave rise to dolly

varden or arctic char. In addition, Cavender (1984) concluded that the

evolutionary distance between bull trout and dolly varden is

significant based on at least four separate chromosomal changes that

separate the two taxa, and that the two species cannot be considered

sister species based on those differences. As a result, the 1994 record

supports the distinction between bull trout and dolly varden.

Bull trout populations are known to exhibit four distinct life

history forms: resident, fluvial, adfluvial, and anadromous. Resident

bull trout spend their entire life cycle in the same (or nearby)

streams in which they were hatched. Fluvial and adfluvial populations

spawn in tributary streams where the young rear from 1 to 4 years

before migrating to either a lake (adfluvial) system or a river

(fluvial) system, where they grow to maturity (Fraley and Shepard

1989). Anadromous fish spawn in tributary streams, with major growth

and maturation occurring in salt water. Diverse life history strategies

are important to the stability and viability of bull trout populations

(Rieman and McIntyre 1993).

Bull trout display a high degree of sensitivity at all life stages

to environmental disturbance and have more specific habitat

requirements than many other salmonids (Fraley and Shepard 1989, Howell

and Buchanan 1992, Rieman and McIntyre 1993). Bull trout growth,

survival, and long-term population persistence appear to be

particularly dependent upon five habitat characteristics: (1) cover,

(2) channel stability, (3) substrate composition, (4) temperature, and

(5) migratory corridors (Rieman and McIntyre 1993).

All life history stages of bull trout are closely associated with

various forms of cover, including large woody debris, undercut banks,

boulders, and pools

[[Page 32269]]

(Fraley and Shepard 1989; Goetz 1989; Hoelscher and Bjornn 1989; Oliver

1979; Pratt 1984, 1985, and 1992; Shepard et al. 1984b; Thomas 1992).

Cover provides critical rearing, foraging, and resting habitat, and

protection from predators (Bryant 1983, Meehan 1991, Salo and Cundy

1987, Sedell and Everest 1991).

Several bull trout life history features make them exceptionally

sensitive to activities directly or indirectly affecting stream channel

integrity and altering natural flow patterns. Juvenile and adult bull

trout frequently inhabit areas of reduced water velocity, such as side

channels, stream margins, and pools that are often eliminated or

degraded by management activities (Rieman and McIntyre 1993). Length

and timing of incubation to emergence (200 days or more during winter

and early spring), the strong association of juvenile fish with stream

channel substrates, and a fall spawning period, make bull trout

particularly vulnerable to altered stream flow patterns and associated

channel instability (Fraley and Shepard 1989, Pratt 1992, Pratt and

Huston 1993, Rieman and McIntyre 1993).

Preferred spawning habitat consists of low gradient streams with

loose, clean gravels (Fraley and Shepard 1989). Fine sediments fill

spaces between the gravel that are needed by incubating eggs and fry.

An extremely long period of residency in the gravel (200 or more days)

makes bull trout especially vulnerable to fine sediments and water

quality degradation (Fraley and Shepard 1989). Juveniles also live on

or within the streambed cobble (Oliver 1979, Pratt 1984). High juvenile

densities were observed in Swan River tributaries with a diverse cobble

substrate and low percentage of fine sediments (Shepard et al. 1984a).

Successful bull trout spawning and development of embryos and

juveniles requires very cold water temperatures (Bjornn and Reiser

1991, Goetz 1989, McPhail and Murray 1979, Pratt 1992). Additionally,

water temperature influences the distribution of juveniles (Fraley and

Shepard 1989, Pratt 1992). Such strict temperature tolerances

predispose bull trout to declines from any activity occurring in a

watershed that leads to increased stream temperatures.

Extensive migrations are characteristic of the species (Fraley and

Shepard 1989, Oregon Department of Fish and Wildlife (ODFW) 1993).

Migratory bull trout facilitate the interchange of genetic material

between populations, ensuring sufficient variability within

populations. Migratory forms also provide a mechanism for restoring

local populations extirpated due to natural or human-caused events

(Rieman and McIntyre 1993, citing others). Migratory forms are more

fecund and larger than non-native brook trout, potentially reducing the

risks associated with hybridization (Rieman and McIntyre 1993). The

greater fecundity of these larger bull trout also enhances the ability

of a population to persist in the presence of introduced fishes (Rieman

and McIntyre 1993). Migratory bull trout have been restricted and/or

eliminated due to stream habitat alterations, including seasonal or

permanent obstructions, detrimental changes in water quality, increased

temperatures, and the alteration of natural stream flow patterns.

Migratory corridors tie seasonal habitat together for anadromous,

adfluvial, and fluvial forms, and allow for dispersal of resident forms

for recolonization of rebounding habitats. The disruption of migratory

corridors, if severe enough, will result in the loss of migratory life

history types and isolate resident forms from interacting with the

metapopulation (U.S. Department of Agriculture (USDA) 1993).

Distinct Population Segments

Pursuant to a court order, the Service evaluated the distribution

of bull trout throughout the species' range for the presence of

distinct population segments in our reconsidered 12-month finding using

the 1994 administrative record. This approach was undertaken because

bull trout occur in widespread but fragmented habitats and have several

life history patterns. In addition, the threats to the fish are

diverse, and the quantity and quality of information regarding the

population status and trends of bull trout varies greatly.

The Service has considered three elements when evaluating the

status of potential distinct population segments--discreteness,

significance, and conservation status. Discreteness refers to the

separation of a population segment from other members of the species

based on either (1) physical, physiological, ecological, or behavioral

factors, or (2) international boundaries that result in significant

differences in exploitation control, habitat management, conservation

status, or regulatory mechanisms. Significance refers to the biological

and ecological importance or contribution of a discrete population to

the species throughout its range. Examples of significance include

persistence of a discrete population segment in a unique or unusual

ecological setting, evidence that loss of discrete segment would result

in a significant gap in the range of the species, or evidence that the

discrete segment differs markedly from other populations of the species

in genetic characteristics.

Based on the 1994 administrative record and as discussed in the

reconsidered 12-month finding, numerous bull trout populations are

isolated from each other because of unsuitable habitat and/or

impassable dams and diversions. Though these isolated populations could

be considered discrete, few populations of bull trout are significant

to the species as a whole. The 1994 record provided evidence of

significance for five distinct population segments: (1) Coastal/Puget

Sound; (2) Klamath River; (3) Columbia River; (4) Jarbidge River; and

(5) Saskatchewan River. Based on the 1994 administrative record, the

Service determined in the reconsidered 12-month finding that listing is

not warranted for the Coastal/Puget Sound, Jarbidge River, and

Saskatchewan River population segments. However, listing is warranted

for the Klamath River and Columbia River population segments based on

the 1994 administrative record.

Klamath River Population Segment

The Klamath River originates in south-central Oregon near Crater

Lake National Park, and flows southwest into northern California where

it meets the Trinity River and empties into the Pacific Ocean. Bull

trout in this drainage are discrete because of physical isolation due

to several small mountain ranges in central Oregon (separating this

population from that of the Columbia River) and the Pacific Ocean.

Leary and Allendorf (1991) determined the genetic structure of bull

trout in the Klamath and Columbia River drainages with the use of

protein electrophoresis. This study concludes that not only are these

two groups of fish reproductively isolated, but also evolutionarily

distinct. In addition, Williams et al. (abstract in: Friends of the

Bull Trout Conference, 1994) separated the Klamath and Columbia River

populations into different clades based on mtDNA diversity patterns. As

a result, the Klamath River population segment is significant to the

taxon because of substantial genetic differences from the Columbia

River populations.

Columbia River Population Segment

The Columbia River population segment includes the entire Columbia

River basin and all its tributaries, excluding the isolated bull trout

populations found in the Jarbidge River

[[Page 32270]]

in Nevada which comprises the Jarbidge population segment. Though

Williams et al. (abstract in: Friends of the Bull Trout Conference,

1994) identified two distinct clades (taxonomic groupings of

descendants by common ancestors) in the Columbia Basin (Upper and Lower

Columbia) based on mtDNA diversity patterns, a discrete geographical

boundary between the two clades was not documented in the record. The

Columbia River population segment is significant because the overall

range of the species would be substantially reduced if this discrete

population were lost.

Status and Distribution

The base of information contained in the 1994 administrative record

regarding the status and trends of bull trout populations throughout

the species' range varies in quantity and quality. The criteria for

defining populations and estimating extinction risks were not

standardized among individual states. Bull trout information from the

state of Montana (primarily Thomas 1992) was the most organized and

complete. In Idaho, with the exception of Lake Pend Oreille and its

tributaries that support an important bull trout fishery, bull trout

status information was incomplete. The status of a majority of Oregon

bull trout populations is unknown. Similar patterns in quality of data

were found for bull trout populations in Canada. Interpretation of

``status unknown'' was the primary problem in status information

contained in the 1994 administrative record.

In 1993, the U.S. Department of Agriculture produced a working

draft concerning the status and conservation needs for bull trout (USDA

1993). This publication, entitled ``An Assessment of the Conservation

Needs for Bull Trout,'' surveyed biologists from State, Federal, and

Tribal agencies, and private industry in the range of bull trout.

Results from this survey represented the most thorough attempt to date

at rangewide classification of bull trout. Survey participants were

requested to fill out forms to provide information on life history,

status, factors influencing status, and whether individual bull trout

populations were considered remnant. The authors noted, that

``[a]lthough the quality of available data was not always consistent

across sources, no attempt was made to account for that variability.''

Many of these data could be described as anecdotal, though a systematic

attempt was made to address the entire species' range.

The appropriate interpretation of the ``remnant'' classification

was the most difficult aspect of the survey to analyze. The 1993

publication classified a remnant population as one in which ``the fish

are known to be present but in very low numbers.'' Additionally, a

remnant classification included the caveat that ``[a]lthough long-term

viability is questionable, the population may constitute a significant

portion of the species gene pool.'' Lacking any population status data

(i.e. declining, stable, secure, or increasing), the Service

interpreted a remnant classification by itself as a ``gap'' in status

information. When a remnant classification was accompanied by status

information other than ``unknown'', the Service generally considered

these data reliable and accurate.

Where population status or trends are known but only for a portion

of a distinct population segment (i.e., there are informational gaps in

1994 record), the Service considered documented trends within a

distinct population segment to be representative of the entire

population segment.

Klamath River Population Segment

Historical accounts suggest that the bull trout was once widely

distributed and exhibited diverse life history traits in the Klamath

Basin. The earliest records of bull trout in the Klamath Basin were

from the late 1800's (Oregon Chapter of the American Fisheries Society

(OCAFS) 1993, citing Cope) and suggested that an adfluvial life history

form occurred in Klamath Lake. Migratory fluvial bull trout evidently

were present in some of the larger streams in the basin as recently as

the early 1970's (Ziller in litt. 1992). Goetz (1989) suggested that

bull trout occurred in 15 separate drainages between 1948 and 1979. By

1989, the distribution of the species had been restricted to 10 streams

in the basin (author unknown, FWS notes, 1993). The most recent data

provided in the 1994 record suggested that in 1991, only seven

segregated resident populations still occurred in the basin and were

confined to headwater streams in the Sprague, Sycan, and Upper Klamath

Lake subbasins. The largest area occupied by any of the seven

populations is 2.5 stream miles, and basinwide, only 12.5 miles of

stream is inhabited by bull trout (Ziller in litt. 1992).

Bull trout occur in four tributaries to the Sprague River subbasin.

Ziller (in litt. 1992) compared abundance estimates between samples

taken in 1979 and 1989 at seven 30-meter sites on Deming, Boulder,

Brownsworth, and Leonard creeks. Ziller found the abundance of bull

trout was relatively unchanged at five sites, increased at one site,

and decreased at one site. In 1991 and 1992, ODFW estimated a total

population size of 3,310 individuals within the 4 segregated

populations of the Sprague River subbasin (OCAFS 1993). The effective

population size was estimated to be 140 to 462 mature fish, with 43

percent of these fish associated with Deming Creek. The remaining 57

percent were split unequally among Boulder, Brownsworth, and Leonard

creeks. Although the Sprague River subbasin contains the healthiest

remaining populations in the Klamath population segment, these

populations are considered to be at a moderate to high risk of

extinction (Ratliff and Howell 1992).

Long Creek may be supporting the only remaining bull trout

population in the Sycan River subbasin. Ratliff and Howell (1992)

suggested that the extinction risks of Long and Coyote creeks were

moderate and high, respectively, based on sampling efforts in 1989.

Sampling efforts in 1990 and 1991 suggest that populations previously

identified in Coyote Creek and the Upper Sycan River are probably

extinct (OCAFS 1993). The total population size in Long Creek was

estimated at 842 individuals with an effective population size of 36 to

119.

Populations in the Upper Klamath Lake subbasin are at precarious

abundance levels, and at a high risk of extinction (Ratliff and Howell

1992). Small populations remain in Sun and Threemile creeks.

Populations in Cherry and Sevenmile creeks are likely to be extinct

(OCAFS 1993). The Sun Creek population was estimated at 133 total

individuals in 1991, with an effective population size of only 11 to 35

mature fish. No abundance estimates were reported for Threemile Creek,

but only nine fish were sampled in the stream during recent surveys.

Because the resident life history trait prevails in the remaining

Klamath River, bull trout populations, size at maturity and associated

fecundity have been reduced in the population from historic conditions.

Average fecundity in 1989 was only 170 eggs/female, and a predominance

of males in the sample suggested a skewed sex ratio of 2.5 males/female

(Rode 1990). These data suggest that the natural recovery potential of

these populations is poor.

In summary, all seven of the remaining populations in the Klamath

River Basin are currently disconnected from each other, and are

considered to be isolated, remnant groups from a historically larger,

more diverse metapopulation. Ratliff and Howell

[[Page 32271]]

(1992) determined each population to be at a moderate or high risk of

extinction. Bull trout occur in three primary subbasins, with the fish

residing in the Upper Klamath Lake subbasin the most precarious. The

Sprague River and Sycan River subbasins each contain isolated

populations within limited available habitat of 2.5 miles or less.

Recent extinctions reportedly have occurred in Coyote Creek and the

Upper Sycan River of the Sycan subbasin, and Cherry and Sevenmile

creeks of the Upper Klamath Lake subbasin (Ratliff and Howell 1992).

Columbia River Population Segment

The Columbia River population segment encompasses a vast geographic

area including portions of Idaho, Montana, Oregon, Washington and

British Columbia. For discussion purposes, this segment was split into

three areas: 1) the Columbia River upstream from the confluence with

the Snake River, 2) the Snake River and its tributaries, and 3) the

Columbia River downstream of the Snake River confluence.

Upper Columbia River

The upper Columbia River portion of the distinct population segment

was separated into four subareas to aid in describing status and

distribution: (1) Kootenai River basin, (2) Clark Fork/Pend Oreille

basin, (3) Spokane River Basin, and (4) Washington tributaries. The

Kootenai River drains the southeastern portion of British Columbia west

of the continental divide, and flows through the extreme northwestern

section of Montana and northern Idaho, before flowing north back into

Canada where it joins the Columbia River. The Clark Fork drains the

majority of area west of the continental divide in Montana before

flowing into Idaho and Lake Pend Oreille. The Pend Oreille River,

including the Priest River and tributaries, flows north and joins the

Columbia River just north of eastern Washington. The Spokane River

drains both the Coeur d'Alene and St. Joe basins and flows west joining

the Columbia River in western Washington. Major Washington tributaries

in the upper Columbia River portion of the distinct population segment

include the Entiat, Wenatchee, Methow, and Yakima rivers.

Kootenai River Basin

Historically, bull trout were likely distributed throughout the

Kootenai River basin (Thomas 1992). Construction of Libby Dam and the

formation of Lake Koocanusa functionally separated bull trout into

different populations. The bull trout population in Lake Koocanusa is,

generally, small in size and constitutes a minor portion of angler

harvest (Thomas 1992). These fish have limited access to spawning

tributaries putting this population at risk (Thomas 1992).

Below Libby Dam, bull trout populations are separated by Kootenai

Falls. Kootenai Falls serves as a natural barrier to upstream migration

(Thomas 1992). Bull trout between Libby Dam and Kootenai Falls rely on

two remaining tributaries, Quartz and Pipe creeks, for spawning.

Historically, bull trout were likely distributed throughout the Fisher

River (tributary to the Kootenai below Libby Dam) since no physical

barriers prevent dispersal. However, Thomas (1992) considered the

status of fluvial bull trout in the Fisher River to be non-viable, or

extinct. Information on bull trout populations in Montana below

Kootenai Falls is incomplete. Several remnant populations are thought

to occur in tributaries including the Yaak River. Of the 99 bull trout

populations evaluated in the Kootenai River basin, all were at least at

moderate risk of extinction, and 47 percent of these were considered to

be at high risk of extinction (Thomas 1992).

Bull trout are considered uncommon in the Idaho portion of the

lower Kootenai River (Esch and Hallock, citing others, 1993). Status is

based on the relatively few individuals that contribute to the sport

catch (1 percent). Based on limited surveys and harvest catch, the

population trend in this portion of the Kootenai River appears to be

declining. Bull trout populations in Kootenay Lake in British Columbia

are considered stable with historic and current harvest rates remaining

relatively high (Esch and Hallock, citing others, 1993).

Clark Fork/Pend Oreille River Basin

The Clark Fork/Pend Oreille River basin drains the largest area in

the Columbia River population segment. Major tributaries of the Clark

Fork are the Flathead, Bitterroot, and Blackfoot rivers. Historically,

strong fluvial, adfluvial, and resident populations of bull trout were

likely distributed throughout the system (Thomas 1992). The healthiest

remaining bull trout populations are adfluvial because passage from

stream to lake environments is unimpeded. Resident populations of bull

trout are remnant and exist in the headwater reaches of tributaries

(Thomas 1992, USDA 1993). Fluvial populations have shown the greatest

decrease concurrent with the construction of mainstem impoundments. For

discussion purposes, the Clark Fork/Pend Oreille Basin is separated

into five areas: Upper Clark Fork (including the Bitterroot and

Blackfoot rivers); Lower Clark Fork (from the Bitterroot confluence

downstream to Lake Pend Oreille, including the Flathead River below

Flathead Lake); Flathead Lake and its tributaries; Lake Pend Oreille

and its tributaries; and Lower Pend Oreille River.

Upper Clark Fork

Historically, fluvial and resident populations of bull trout

probably inhabited the entire upper mainstem Clark Fork (Thomas 1992).

However, due to mining related stream degradation, these populations

have become increasingly rare, or, in some cases, extirpated entirely

from former habitats (Thomas 1992). Natural recolonization of these

populations seems remote due to continued habitat problems and the

absence of strong fluvial populations downstream. Bull trout are

considered rare in many tributaries with most remaining populations at

a high risk of extinction (Thomas 1992).

The healthiest remaining Clark Fork tributary population of bull

trout is Rock Creek (Thomas 1992). Rock Creek generally has had

relatively few impacts from humans, which undoubtedly has positively

influenced this population. Conversely, Flint Creek has experienced a

substantially higher degree of perturbation and consequently, this

population is considered to be in perilous condition (Thomas 1992).

However, the majority (86 percent) of bull trout in Flint and Rock

creeks combined are considered to be at moderate risk of extinction.

The Blackfoot River is one of the largest tributaries to the upper

Clark Fork River. Historically, the Blackfoot contained resident and

fluvial populations of bull trout. The fluvial component is thought to

have had connections with the mainstem Clark Fork. This connection was

broken in the early 1900's by the construction of Milltown Dam, which

effectively isolated bull trout in the Blackfoot from populations in

the mainstem Clark Fork (Thomas 1992). Fluvial populations of bull

trout still use the mainstem Blackfoot; however, their population

status is unknown. Isolated populations of adfluvial and resident fish

still exist within the basin. In the Blackfoot River, Peters (1990)

found juvenile bull trout in only 40 percent of tributary streams

surveyed in 1989, leading to a conclusion that Blackfoot bull trout

[[Page 32272]]

were in jeopardy. None of the remaining populations are classified as

abundant, and only three populations within the system are considered

common. Overall, 66 percent and 32 percent of bull trout populations in

the Blackfoot River were considered at a moderate and high risk of

extinction, respectively (Thomas 1992).

Bull trout were historically distributed throughout the mainstem

Bitterroot River and its tributaries (Thomas 1992). Bull trout now

appear to be extinct in the majority of the mainstem Bitterroot River.

Though tributary streams contain small isolated populations of bull

trout, many are sympatric with non-native brook trout. Bull trout are

considered abundant or common in 30 percent of the surveyed Bitterroot

stream reaches, and uncommon or rare in 70 percent (Thomas 1992).

Ninety-six percent of the bull trout populations in the Bitterroot

system are considered to be small, fragmented, and at a moderate to

high risk of extinction (Thomas 1992).

Lower Clark Fork

The Lower, or mainstem, Clark Fork River is segmented by several

impoundments that do not provide fish passage. Above Lake Pend Oreille,

Cabinet Gorge, Noxon Rapids, and Thompson Falls facilities separate the

mainstem river. Historically, a natural barrier existed at Thompson

Falls that prevented upstream passage. Prior to mainstem impoundments,

migrating bull trout from Lake Pend Oreille likely used the tributaries

below Thompson Falls for spawning (Thomas 1992). In addition, this area

probably supported fluvial and resident populations of bull trout.

Currently, bull trout are uncommon in the mainstem Clark Fork River,

and all remaining populations are considered at moderate risk of

extinction (Thomas 1992).

Populations of fluvial bull trout probably occurred historically

throughout the drainage above Thompson Falls (Thomas 1992). Adfluvial

fish from Lake Pend Oreille probably did not use this area due to the

natural barrier created by Thompson Falls. Thomas (1992) suggested that

adfluvial bull trout from Flathead Lake may have migrated downstream.

The construction of Kerr Dam blocked passage between Flathead Lake and

the lower Flathead and Clark Fork rivers. Bull trout in the mainstem

Clark Fork are considered rare or uncommon (Thomas 1992). Several

important tributaries still serve as spawning grounds with many

tributary populations existing at low numbers. Limited information

exists on bull trout status in the lower Flathead River. Currently,

bull trout are the least common salmonid found in the Flathead River

below Kerr Dam. Of the 199 populations evaluated in the Lower Clark

Fork and Flathead rivers, Thomas (1992) reported that 44 percent were

at high risk of extinction and 56 percent were at moderate risk of

extinction.

Flathead Lake

As in other areas in Montana, the actual historic distribution of

bull trout in the Flathead Lake system is unknown. However, with few

natural barriers and abundant interconnected habitat, bull trout likely

were distributed throughout the system (Thomas 1992). Undoubtedly,

resident and fluvial forms occupied areas within the drainage, but in

the Flathead Lake system the adfluvial lifestage would most likely have

had a distinct advantage. The larger adult size and increased

reproductive potential would probably have made this the dominant life

history form. Primary tributaries of Flathead Lake included the North,

South, and Middle forks of the Flathead River, Swan River, and

Stillwater River.

The interconnectedness of the Flathead system has been disrupted by

the construction of several hydroelectric facilities that block

historic migration corridors. Big Fork Dam on the Swan constructed in

1902 blocked bull trout passage into the Swan River drainage.

Similarly, the completion of Hungry Horse Dam in 1953 on the South Fork

Flathead River further isolated bull trout populations. As previously

mentioned, Kerr Dam blocks passage from the lower Flathead River into

Flathead Lake. The North and Middle forks of the Flathead River still

have relatively unimpeded passage into Flathead Lake.

Thomas (1992) reported that the Flathead system contained one of

the most viable populations of adfluvial bull trout left in the

coterminous United States. The viability of bull trout in the Flathead

system should be qualified given more recent monitoring data that

suggest certain populations within the system are declining.

Spawning redd counts in the North Fork (1991) and Middle Fork (1990

and 1991) Flathead rivers have decreased. The 1991 redd count

information in the North Fork was 34 percent below the annual average.

Redd counts in the Middle Fork during 1990 and 1991 were 43 percent and

28 percent below the annual average, respectively (Thomas 1992). Trend

analysis, including redd count surveys from 1992 and 1993, indicate a

significant decline in redd counts over a 15-year monitoring period

(Weaver 1994). Moreover, the recent estimated rate of decline (7-year

period) is significantly greater than the 15-year rate of decline. Bull

trout redd counts reached the lowest observed levels in 1992 and 1993.

Annual rate of decline was estimated at 16 redds per year based on the

15-year observation period, and 60 redds per year using the recent 7-

year period of record.

Analysis of redd count trend information for four North Fork

Flathead tributaries found a moderate level of annual variability

within the system (Rieman and McIntyre 1993). Using the same

information, the authors calculated a probability of 100-year

persistence for each population, based on an extinction threshold of 10

redds, alternate year spawning, and an instantaneous growth rate of

zero. Of the four populations examined, all were below 50 percent

probability of persistence. When actual estimates for instantaneous

growth rate were used, all four populations were still below the 50

percent probability of persistence over the next 100 years.

Rieman and McIntyre (1993) conducted the same analysis of redd

count trend information for four Middle Fork Flathead tributaries and

found a low to moderate level of annual variability within the system.

Of the four populations examined, two populations were below 50 percent

probability of persistence (40 percent and 29 percent), while fish in

two tributaries had moderate to high probabilities for persisting (60

percent and 71 percent). When actual estimates for instantaneous growth

rate were used, all four populations were below the 50 percent

probability of persistence over the next 100 years.

Despite this apparent decline, and uncertain probabilities for

persistence in bull trout populations in the North and Middle forks of

the Flathead, each tributary still contains areas of pristine habitat

and healthy bull trout (Thomas 1992). Adfluvial populations of bull

trout in Glacier National Park reside in high quality habitat with

little or no exposure to non-native species. Similarly, the Middle Fork

of the Flathead still contains viable populations of bull trout (Thomas

1992). Overall, while referred to as a bull trout stronghold, Thomas

(1992) reported that 91 percent of the populations in the North and

Middle Fork of the Flathead River are at a moderate risk of extinction.

The remaining 9 percent are judged to be at low risk of extinction.

Little population information was available from the 1994

administrative record regarding bull trout population status in the

South Fork of the Flathead River prior to the construction of

[[Page 32273]]

Hungry Horse Dam. As previously stated, Hungry Horse Dam was built

without allowing for fish passage, and this functionally isolated

adfluvial populations of bull trout which would have migrated to

Flathead Lake. This blockage resulted in a net loss of 38 percent of

the available bull trout spawning habitat (Thomas 1992). Fish that were

trapped behind Hungry Horse Dam established a new adfluvial population

using the newly formed reservoir. Remote spawning locations in the Bob

Marshall Wilderness Area have hampered collection of redd count

surveys. However, where information is available, 83 percent of the

remaining bull trout populations in the South Fork of the Flathead

River are considered to be at a moderate risk of extinction (Thomas

1992).

Historically, the Swan River supported an adfluvial population of

bull trout that migrated to Flathead Lake (Thomas 1992). Construction

of Bigfork Dam in 1902 effectively blocked passage and isolated this

population. Subsequently, a new adfluvial population developed in Swan

Lake. The Swan Lake drainage also supports isolated resident

populations of bull trout (Thomas 1992). Thomas (1992) reported that

adfluvial bull trout in Swan Lake represent the healthiest population

in the Flathead system. Based on redd counts, Swan Lake bull trout

spawner densities appear to be higher than those in Flathead Lake

(Thomas citing others 1992). Trend analysis based on redd counts for

the Swan River system indicates that adfluvial bull trout populations

are increasing (Weaver 1994). In addition, the 1993 redd count was the

highest recorded, and represented a 57 percent increase over an 11-year

average. In spite of this, Thomas (1992) considered bull trout in Swan

Lake and Swan River to be at moderate risk of extinction.

Rieman and McIntyre (1993) conducted the same analysis of redd

count trend information for four Swan River tributaries and found a low

to high level of annual variability within the system. Of the four

populations examined using an instantaneous growth rate of zero, two

populations were below 50 percent probability of persistence (43

percent and 49 percent), while fish in two tributaries had moderate to

high probabilities for persisting (65 percent and 74 percent). When

actual estimates for instantaneous growth rate were used, all three

populations had high probabilities for persistence (two populations at

greater than 95 percent and 80 percent respectively) over the next 100

years (Rieman and McIntyre 1993). Conversely, one tributary had a low

probability of persistence (4 percent).

Bull trout populations in the Stillwater River are depressed and

are considered at a high risk of extinction (Thomas 1992).

Historically, bull trout were probably distributed throughout the

Stillwater system. While several lakes still contain adfluvial

populations of bull trout, poor habitat conditions and non-native

species interactions have made the occurrence of bull trout uncommon.

Lake Pend Oreille

The Lake Pend Oreille system in the upper Columbia River is

delineated upstream by Cabinet Gorge Dam on the Clark Fork River.

Constructed in 1951, Cabinet Gorge Dam blocked upstream passage and

functionally isolated adfluvial bull trout from numerous tributary

spawning areas. Similarly, the Lake Pend Oreille system is isolated

downstream by Albeni Falls Dam (1952) on the mainstem Pend Oreille

River. The major tributary to the Pend Oreille system in this area is

the Priest River, that enters the Pend Oreille River downstream of Lake

Pend Oreille.

Historical accounts indicate that bull trout were common throughout

the Pend Oreille system (Esch and Hallock, citing others). These

accounts undoubtedly included resident, fluvial, and adfluvial

lifecycles. As was the case with bull trout in the Flathead system, an

adfluvial lifecycle in Lake Pend Oreille would have been advantageous,

and annual spawner escapement may have reached 10,000 fish (Pratt and

Houston 1993). Annual population estimates indicated that between 1,100

and 2,000 adfluvial bull trout may occur in Lake Pend Oreille (Pratt

and Houston 1993).

Analysis of redd count trend information for six Lake Pend Oreille

tributaries found a high degree of annual variability within the system

(Rieman and McIntyre 1993). The authors calculated a probability of

100-year persistence for each population, based on an extinction

threshold of 10 redds, alternate year spawning, and an instantaneous

growth rate of zero. Of the six populations examined, four populations

were below 50 percent probability of persistence, while fish in the

remaining two tributaries had high probabilities for persisting (87

percent and greater than 95 percent). When actual estimates for

instantaneous growth rate were used, five of the populations were below

the 40 percent probability of persistence over the next 100 years. Only

one Lake Pend Oreille tributary had a high probability of persistence

(88 percent).

Since 1983, portions of 21 different tributaries to Lake Pend

Oreille have been surveyed for bull trout redds (Idaho Bull Trout

Survey, no date). Year to year consistency in sampling each site has

varied. Of the 21 tributary locations, only 6 index streams were

surveyed from 1983 through 1992. These tributaries are East Fork

Lightning, Johnson, Trestle, Grouse, North Gold, and Gold creeks. This

sampling represents some of the best trend information in the 1994

administrative record concerning Lake Pend Oreille. During this period,

redd counts in index streams varied from a high of 671 in 1985, to a

low of 290 in 1986. The 1992 stream index redd count of 344 is 31

percent below the 9-year average of 500.

Pend Oreille River

The Priest River is the only remaining tributary of the Pend

Oreille River below Lake Pend Oreille still supporting bull trout

(Pratt and Houston 1993). As recently as 1972, bull trout were

documented in seven tributaries of the Priest River below Priest Lake.

However, in 1987, only three of these tributaries were found to contain

bull trout. The reduction in bull trout abundance in Priest Lake has

been reflected in decreased annual harvest (Mauser 1985). Between 1956

and 1970, an annual average of 1,200 bull trout were harvested in

Priest Lake. In 1978, a record harvest of 2,320 fish occurred, but by

1983 this number had decreased to only 159 fish. Interactions with lake

trout and overharvest have nearly extirpated the Priest Lake bull trout

population (Esch and Hallock, citing others). Bull trout are still

found in Upper Priest Lake and are considered to be healthy and a

possible source of bull trout for the lower lake. Evidence also exists

for the decline in redd counts in tributaries of both lakes (Esch and

Hallock, citing others). Overall, Priest Lake is considered to be at a

high risk of extinction, while Upper Priest Lake is thought to be at a

moderate risk.

Little information is available in the 1994 administrative record

regarding bull trout status in the lower Pend Oreille River. Below Lake

Pend Oreille and Albeni Falls Dam, mainstem impoundments have

fragmented fluvial bull trout habitat. Historic records and accounts

indicate that fluvial bull trout were numerous (C. Vail, WDW, undated

USFS survey). The current bull trout population is considered remnant

and at a high risk of extinction (WDW 1992).

Spokane River Basin

Little information is available in the 1994 record concerning bull

trout status

[[Page 32274]]

in the Spokane River basin. It is assumed, however, that adfluvial,

fluvial, and resident bull trout were distributed throughout the system

including the Coeur d'Alene River, Lake Coeur d'Alene, and the St. Joe

River drainage (Draft Conservation Plan, Idaho Department of Fish and

Game (IDFG), Draft Bull Trout Conservation Plan for the Upper Spokane

River Basin, no date). Restricted to Lake Coeur d'Alene and the St. Joe

River, spawning appears to occur in only ten tributaries in headwater

reaches of the system. The Coeur d'Alene subbasin is currently

considered of special concern and at high risk of extinction (D. Cross,

USFS, in litt. 1992). The St. Joe system is considered of special

concern and at moderate risk of extinction.

In the Spokane River subbasin of the Columbia, stream surveys in

1935 and 1940 documented the presence of bull trout throughout the St.

Joe River (USFS 1935; Maclay 1940). By 1992, the occupied range in the

upper one-third of this river was reduced by 76 percent (Cross, pers.

comm. 1993). Similar reductions have occurred in the Coeur d'Alene

River drainage, where bull trout range may have been reduced 90 percent

since surveys in 1940; presently bull trout may persist in only one

isolated tributary in the entire drainage (Maclay 1940; Lider, USFS,

pers. comm. 1994). Due to low numbers of fluvial spawners, bull trout

in the Spokane River subbasin were estimated to have a moderate risk of

extinction (Hoelscher, IDFG, in litt. 1992).

Washington State Tributaries

Historically, bull trout probably inhabited a majority of the

tributaries to the upper Columbia River in Washington. In these

tributaries, bull trout distribution has been significantly restricted

and several populations, including the Okanogan River, Lake Chelan, and

lower Yakima River, are extirpated (WDW 1992). Currently, 17

populations of bull trout occur in Washington above the Snake River

confluence (WDW 1992). These populations include adfluvial, fluvial and

resident components. Subbasins within the upper Columbia River still

supporting bull trout are the Entiat, Methow, Naches, Wenatchee, and

Upper Yakima drainages (WDW 1992). Of these populations, three are

declining, seven are stable, and one population is considered secure.

The status of the six remaining bull trout populations is unknown.

Within the upper Columbia River, risk of extinction was calculated

for bull trout populations where the status was known (WDW 1992).

Populations with unknown status were not classified by risk of

extinction, but were given a priority ranking for information needs.

Bull trout populations in Kachess and Keechelus Lakes (Upper Yakima

River drainage), Roosevelt Lake, and the Pend Oreille River were

considered to be at high risk of extinction (WDW 1992). Four bull trout

populations in the Entiat, Methow, and Wenatchee River basins were

classified as being at moderate risk of extinction (WDW 1992).

Similarly, four other tributary populations in the Wenatchee, Methow,

and Naches River basins were considered to be at low risk of extinction

(WDW 1992). One tributary of the Methow River was considered to be at

no immediate risk (WDW 1992). The remaining four bull trout populations

in the upper Columbia River (Naches and Upper Yakima rivers) had an

unknown status and were not classified.

Bull trout populations in the Entiat, Upper Yakima, Wenatchee,

Methow and Naches occur in isolated segments and appear to be sparse in

abundance (Brown 1992, WDW 1992). However, certain populations

including the Chiwawa River and Rimrock Lake appear to be stable. In

Rimrock Lake and Indian Creek (spawning tributary) redd counts

increased from 29 in 1986, to 140 in 1993 (Yakima County Bull Trout

Status 1994; E. Anderson, WDW, in litt. 1994). The Chiwawa River is

recognized as having one of the stronger populations in the mid-

Columbia River (Brown 1992). While long-term trend data on the Chiwawa

River and tributaries were not available during 1991, 348 bull trout

redds were counted in this system.

Snake River and Tributaries

Historically, bull trout were likely widely dispersed throughout

the Snake River drainage, limited only by natural passage and thermal

barriers (Esch and Hallock, citing others). Current distribution is

primarily relegated to tributaries to the mainstem Snake River upstream

to and including the Boise River (Esch and Hallock, citing others).

Major tributaries of the Snake River in Oregon currently supporting

bull trout populations include the Tucannon, Grande Ronde, Imnaha, and

the Malheur. In Idaho, bull trout can be found in the Clearwater,

Salmon, Weiser and Boise river drainages.

Ratliff and Howell (1992) compiled a status assessment of Oregon

bull trout populations. Status was determined subjectively based on

relative abundance, suppressing factors, and recovery potential of

identified populations. In the 29 Oregon tributaries of the Snake River

where bull trout are found, 7 percent are considered to be at high risk

of extinction, while 14 percent are thought to be at low risk (Ratliff

and Howell 1992). The majority of bull trout populations are either at

moderate risk (38 percent) or are of special concern (34 percent).

Seven percent of the examined populations are considered to be extinct.

Of the 29 populations, 62 percent are classified as remnant, while 76

percent of the populations have a current status of unknown. Based on

limited information, a few tributaries, including portions of the

Grande Ronde, Minam River, and the North Fork of the Malheur, appear to

have viable bull trout populations (Ratliff and Howell 1992, Bowers et

al. 1993). Of the 10 identified Snake River bull trout populations

occurring in Washington, the status of 40 percent are declining, 30

percent stable, and 30 percent unknown (WDW 1992).

The quality and quantity of bull trout information for Snake River

tributaries in Idaho is poor. Limited spot surveys indicate that bull

trout may be widespread throughout the Clearwater and Snake River

drainages. However, the lack of identified populations and associated

trend information complicates status evaluation. The Rapid River is one

of the largest remaining bull trout populations for which long-term

trend information is available. Bull trout counts from a fish weir on

this Salmon River tributary averaged 206 fish between 1973-91 (Rieman

and McIntyre 1993).

Analysis by Rieman and McIntyre (1993) calculated a probability of

100-year persistence for Rapid River bull trout. Using weir counts

taken over a period of 19 years, the authors assumed a 1:1 sex ratio

and one female per redd to approximate the mean number of redds per

year in the spawning escapement. Based on this information, an

extinction threshold of 10 redds, alternate year spawning, and an

instantaneous growth rate of zero, the Rapid River population had a 58

percent probability of persistence. When the actual estimate for

instantaneous growth rate was used, the probability for persistence

increased to 74 percent.

Population trend data is also lacking for bull trout in the Weiser,

Payette, and Boise rivers. IDFG (1993) suggested that bull trout were

widely distributed in the Payette and Boise rivers, but restricted to

only two tributaries in the Weiser River. Density estimates for Sheep

and Anderson creeks of the Weiser drainage ranged from 2.8 to 5.2 bull

trout/100 square meters in 1992 (IDFG 1993), but no earlier data was

reported to establish

[[Page 32275]]

a trend. Neither historical nor current abundance data is available for

the Payette or Boise rivers, but Renstrom (no affiliation, in litt.

1993) indicated that bull trout are quite common in the upper reaches

of the North Fork Boise River and Johnson Creek; they often dominate

the sport catch in these systems.

Lower Columbia River

The lower Columbia River encompasses a large geographic area

including portions of Washington and Oregon. The lower Columbia River

includes the mainstem Columbia River and all tributaries below the

Snake River confluence. Major tributaries include the John Day,

Deschutes, and Willamette rivers.

The 1994 administrative record on bull trout status in the lower

Columbia River is largely incomplete. A significant portion of bull

trout status information for Washington and Oregon is unknown (USDA

1993, WDW 1992). Where sufficient data existed to determine status, 40

percent were declining, 5 percent stable, and 15 percent secure. The

status of the remaining 40 percent of lower Columbia River populations

in Oregon was unknown. Of the six lower Columbia River bull trout

populations identified in Washington all are considered remnant, with

17 percent classified as stable, and 83 percent as ``status unknown''

(WDW 1992).

Based on the 1994 administrative record, bull trout populations

within the lower Columbia River have declined from historic levels.

Remaining populations are generally considered to be isolated and

remnant (Ratliff and Howell 1992, USDA 1992). Historic bull trout

populations of the lower Columbia River consisted of adfluvial,

fluvial, and resident components. While each lifecycle is still

represented, the resident form is dominant, followed by the fluvial,

and adfluvial (USDA 1992).

Within the Oregon portion of the lower Columbia River, 23 percent

of bull trout populations are considered to be at a high risk of

extinction, while 15 percent are thought to be at a moderate risk, 12

percent of special concern, 19 percent at low risk, and 31 percent are

extinct (Ratliff and Howell 1992). In Washington, using a different

risk assessment method (WDW 1992), only the bull trout population in

Yale Reservoir was considered at risk (moderate). The remaining five

bull trout populations were not evaluated with respect to risk of

extinction due to a ``status unknown'' classification (WDW 1992).

The primary tributaries to the lower Columbia River still

containing bull trout are the Walla Walla, Umatilla, John Day,

Deschutes, Hood, Lewis, and Willamette rivers. With the exception of

the Deschutes River basin, remaining populations are dominated by

small, isolated, remnant populations. Long-term population trend

information contained in the 1994 administrative record is incomplete

or lacking for the remaining bull trout populations. Where information

was available, the low abundance, and fragmented nature of these

headwater populations is apparent.

An example of the variable and contradictory information found in

the 1994 administrative record is illustrated by the John Day River

basin. Based on bypass trap information from 1971-1992, bull trout

counts on the Upper John Day River have been as high as 345 in 1973 to

as low as 12 in 1988 (ODFW 1993). While the 1971-80 average of 152 was

larger than the 1981-92 average of 95, the mean counts were not

statistically different (p 0.05), and the 1992 bull trout

count (232) was the third highest on record. Ratliff and Howell (1992)

consider the Upper John Day River to be at moderate risk of extinction.

Similar trend information in the Middle Fork or the North Fork of the

John Day was not available. These populations are isolated and occur at

low numbers, and Ratliff and Howell (1992) considered Middle Fork to be

at high risk and North Fork of special concern.

The quality of bull trout population status information varies in

the Umatilla, Walla Walla, Hood, Willamette, and Lewis rivers.

Populations in the Umatilla, Walla Walla, and Hood rivers are

considered at low risk or of special concern (Ratliff and Howell 1992,

WDW 1992). Other populations in the Hood and Willamette systems are

considered to be at high risk of extinction. Based on direct counts and

professional judgement these populations are isolated via impoundments

or habitat degradation and are at low levels. Ratliff and Howell (1992)

considered these populations to be at moderate to high risk of

extinction.

The strongest remaining population of bull trout in the lower

Columbia River is the adfluvial population located in the Deschutes

River basin. Lake Billy Chinook and the Metolius River still support a

viable population bull trout as documented by increasing redd counts

from 1986-93 (Ratliff 1994). This population has benefitted from

restrictions in harvest regulations and is considered at low risk of

extinction (Ratliff and Howell 1992). Shitike Creek below lake Billy

Chinook still supports a relatively good population of fluvial bull

trout, which Ratliff and Howell (1992) considered to be at low risk of

extinction. The remaining bull trout populations in the Deschutes

system are not doing as well. Bull trout populations in the upper

Deschutes are either extinct or considered to be at high risk of

extinction in the future (Ratliff and Howell 1992).

Summary of Columbia River Population Segment

Based on the 1994 administrative record, bull trout populations

within the upper Columbia River have declined from historic levels

(Thomas 1992 and USDA 1993). Overall, remaining populations are

generally considered to be isolated and remnant (Rieman and McIntyre

1993, Thomas 1992, USDA 1993). Fluvial bull trout populations in the

upper Columbia River portion of the distinct population segment appear

to be nearly extirpated. Resident populations existing in headwater

tributary reaches are isolated and generally low in abundance (Thomas

1992). Based on information in the 1994 record, bull trout in Flathead

Lake and Lake Pend Oreille appear to be declining. The adfluvial

population in Swan Lake appears to be increasing and represents the

healthiest remaining population.

The 1994 administrative record on bull trout populations within the

Snake River and tributaries is largely incomplete. However, with the

lack of passage barriers, historic distribution throughout the system

was probable. Overall, the lack of specific trend information for the

Snake River made the analysis of population status difficult. Certain

populations appeared to be stable, while others were at a moderate to

high risk of extinction (Ratliff and Howell 1992).

Historic distribution of bull trout within the lower Columbia River

cannot be verified, but adfluvial, fluvial, and resident forms were

likely widely distributed throughout the area (Ratliff and Howell

1992). Current distribution is fragmented with dispersed remnant

populations of resident and fluvial bull trout inhabiting tributaries

(Ratliff and Howell 1992, USDS 1993, WDW 1992). Certain populations

appeared to be stable, while others were at high risk of extinction

(Ratliff and Howell 1992, WDW 1992).

The general trend of bull trout populations in the Columbia River

population segment where status is known is declining. An examination

of 386 bull trout populations in the Columbia River population segment

[[Page 32276]]

indicated that 33 percent are declining, 15 percent stable, 3 percent

secure, and 2 percent increasing (Ratliff and Howell 1992, USDA 1993,

and WDW 1992). The population status of the remaining 47 percent is

unknown. Of the 386 bull trout populations, 44 percent are considered

remnant, 30 percent not remnant, and 26 percent unknown (Ratliff and

Howell 1992, USDA 1993, WDW 1992).

Previous Federal Action

On September 18, 1985, the Service published an animal notice of

review in the Federal Register (50 FR 37958) designating the bull trout

a category 2 candidate for listing in the coterminous United States.

Category 2 taxa were those for which conclusive data on biological

vulnerability and threats were not currently available to support

proposed rules. The Service published updated notices of review for

animals on January 6, 1989 (54 FR 554), and November 21, 1991 (56 FR

58804), reconfirming the bull trout category 2 status. The Service

elevated bull trout in the coterminous United States to category 1 for

Federal listing on November 15, 1994 (59 FR 58982). Category 1 taxa

were those for which the Service had on file substantial information on

biological vulnerability and threats to support preparation of listing

proposals. Upon publication of the February 28, 1996, notice of review

(61 FR 7596), the Service ceased using category designations and

included the bull trout as a candidate species. Candidate species are

those for which the Service has on file sufficient information on

biological vulnerability and threats to support proposals to list the

species as threatened or endangered.

On October 30, 1992, the Service received a petition to list the

bull trout as an endangered species throughout its range from the

following conservation organizations in Montana: Alliance for the Wild

Rockies, Inc., Friends of the Wild Swan, and Swan View Coalition

(petitioners). The petitioners also requested an emergency listing and

concurrent critical habitat designation for bull trout populations in

select aquatic ecosystems where the biological information indicates

that the species is in imminent threat of extinction. A 90-day finding,

published on May 17, 1993 (58 FR 28849), determined that the

petitioners had provided substantial information indicating that

listing of the species may be warranted. The Service initiated a

rangewide status review of the species concurrent with publication of

the 90-day finding.

On June 6, 1994, the Service concluded in the original 12-month

finding that listing of bull trout throughout its range was not

warranted due to unavailable or insufficient data regarding threats to,

and status and population trends of, the species within Canada and

Alaska. However, the Service determined that sufficient information on

the biological vulnerability and threats to the species was available

to support a warranted finding to list bull trout within the

coterminous United States. Because the Service concluded that the

threats were imminent and moderate to this population segment, the

Service gave the bull trout within the coterminous United States a

listing priority number of 9. As a result, the Service found that

listing a distinct vertebrate population segment of bull trout residing

in the coterminous United States was warranted, but precluded due to

higher priority listing actions.

On November 1, 1994, Friends of the Wild Swan, Inc. and Alliance

for the Wild Rockies, Inc. (plaintiffs) filed suit in the Federal

District Court of Oregon arguing that the warranted but precluded

finding was arbitrary and capricious. After the Service issued a

``recycled'' 12-month finding for the coterminous population of bull

trout on June 12, 1995, the district court issued an order declaring

the plaintiffs' challenge to the original finding moot. The plaintiffs

declined to amend their complaint and appealed to the Ninth Circuit

Court of Appeals, which found that the plaintiffs' challenge fell

``within the exception to the mootness doctrine for claims that are

capable of repetition yet evading review.'' On April 2, 1996, the

circuit court remanded the case back to the district court. On November

13, 1996, the district court (Court) issued an order and opinion

remanding the original finding to the Service for further

consideration. Included in the instructions from the Court were

requirements that the Service limit its review to the 1994

administrative record, and incorporate any emergency listings or high

magnitude threat determinations into current listing priorities. In

addition, reliance on other Federal agency plans and actions was

precluded. The reconsidered 12-month finding was delivered to the Court

on March 13, 1997. This finding determined that the Klamath River and

Columbia River population segments warranted listing based on the 1994

administrative record.

On March 24, 1997, the plaintiffs filed a motion for mandatory

injunction to compel the Service to issue a proposed rule to list the

Klamath and Columbia bull trout populations within 30 days based solely

on the 1994 administrative record. In response to this motion, the

Service ``concluded that the law of this case requires the publication

of a proposed rule'' to list the two warranted populations. On April 4,

1997, the Service requested 60 days to prepare and review the proposed

rule. In a stipulation between the Service and plaintiffs filed with

the Court on April 11, 1997, the Service agreed to issue a proposed

rule in 60 days to list the Klamath River population of bull trout as

endangered and the Columbia River population of bull trout as

threatened based solely on the 1994 record. As a result, the Service

did not consider any information received since the close of the 1994

record in the development of this proposal.

The processing of this proposed rule conforms with the Service's

final listing priority guidance published in the Federal Register on

December 6, 1996 (61 FR 64475). The guidance clarifies the order in

which the Service will process rulemakings during fiscal year 1997. The

guidance calls for giving highest priority to handling emergency

situations (Tier 1), second highest priority (Tier 2) to resolving the

listing status of the outstanding proposed listings, and third priority

(Tier 3) to new proposals to add species to the list of threatened and

endangered plants and animals. This proposed rule constitutes a Tier 3

action.

Summary of Factors Affecting These Species

Procedures found in section 4 of the Endangered Species Act (16

U.S.C. 1533) and regulations (50 CFR part 424) promulgated to implement

the Act set forth the procedures for adding species to the Federal

lists. A species may be determined to be an endangered or threatened

species due to one or more of the five factors described in section

4(a)(1). These factors and their application to the Klamath River

population segment and Columbia River population segment of bull trout

(Salvelinus confluentus) are as follows:

A. The present or threatened destruction, modification, or

curtailment of its habitat or range. According to the 1994

administrative record, many instream habitat features have been

significantly impaired as a result of land management activities,

including forest management and road building, hydropower and

irrigation diversions, mining, and grazing (Chamberlain et al. 1991,

Craig and Wissmar 1993, Frissell 1993, Furniss et al. 1991, Isaacson

1994, Meehan 1991, Nehlsen et al. 1991, Salo and Cundy 1987, Sedell and

Everest 1991). Based on a survey of biologists, only 18

[[Page 32277]]

percent of all bull trout populations and stream segments rangewide are

not threatened by degraded habitat conditions (USDA 1993). Adverse

impacts to bull trout habitat and populations due to land management

practices have been documented throughout the species' range in the

conterminous United States (Brown 1992, Fraley and Shepard 1989, Goetz

1989, Howell and Buchanan 1992, Isaacson 1994, Meehan and Bjorn 1991,

Platts et al. 1993, Pratt 1992, Pratt and Huston 1994, Rieman and

McIntyre 1993, Shepard et al. 1984a, 1984b, Thomas 1992, USDA 1993,

Weaver and Fraley 1991, WDW 1992). While some bull trout persist in

``managed'' drainages (Hicks, Plum Creek Timber Company, in litt.,

1993), it is likely that these populations are at risk of extinction

(Rieman and McIntyre 1993).

Forest management has degraded bull trout habitat throughout the

species' range. Logging and road building activities threaten bull

trout populations within and downstream of managed areas through

increased sediment production and delivery to streams, reduced

streamside canopy closure, increased stream temperatures, and reduced

woody debris recruitment (Chamberlain et al. 1991, Furniss et al. 1991,

Weaver and Fraley 1991, Thomas 1992, Isaacson 1994). Thousands of miles

of logging roads and vast acreage of recently logged watersheds will

continue to impact hydrologic functions and habitat quality throughout

the species' range for at least several decades (Isaacson 1994).

While forest management activity is cited as a contributor to bull

trout population decline, the precise impact of a specific activity or

accumulation of activities on the abundance, resilience or long-term

persistence of a population is unknown (USDA 1993). Haugen (1991)

estimated that salmonid habitat had been reduced in the Columbia Basin

by about 24 percent in the past century as a result of these land

management practices. On National Forests, most habitat alterations

occurred during the period 1940-1970 when forest management focused on

commodity resources.

Dam and reservoir construction and operation have significantly

altered major portions of the riverine habitats of bull trout

throughout the Columbia River Basin. Numerous dams without adequate

fish passage have created barriers to fluvial and adfluvial bull trout,

precluding access to former spawning, rearing, and migration habitats

(Craig and Wissmar 1993, WDW 1992b, ODFW 1993). Altered hydrographs and

water quality conditions may also degrade bull trout forage bases

(Marotz 1993). Many migratory bull trout populations associated with

mainstem river systems have been extirpated due to the construction of

dams, particularly in the Columbia Basin (Brown 1992, Goetz 1991, WDW

1992a, ODFW 1993). The completion of McCloud Dam in 1965 has been cited

as the primary cause of bull trout extirpation from California (Rode

1990).

Connectivity within and between watersheds is essential for

maintaining aquatic ecosystem functions and healthy bull trout

populations (Rieman and McIntyre 1993). Numerous hydroelectric and

water storage dams currently isolate a large number of bull trout

populations rangewide. The construction of hydropower dams on major

river tributaries has isolated upper basin populations, and eliminated

the downstream fluvial or adfluvial life history forms dependent on

upstream spawning habitat. Irrigation and hydroelectric dams, large and

small, have blocked bull trout migration in almost all drainages in the

Pacific Northwest and converted riverine habitats into reservoir

habitats (Platts et al. 1993). In many instances, natural

recolonization of historically occupied bull trout sites has become

impossible. But, movement of introduced species or undesirable species

may also be controlled by a dam, thus, enabling bull trout to utilize

historic habitats without competition from non-indigenous species.

Impacts associated with agriculture, including irrigation and water

storage activities, have adversely impacted bull trout habitat.

Agricultural activities reduce streamside cover, increase

sedimentation, and introduce point and non-point source pollution.

Unscreened irrigation diversions likely trap juvenile bull trout

migrating downstream (Ratliff and Howell 1992).

Grazing impacts to salmonid habitat have been described by many

authors (Platts 1991, Elmore and Beschta 1987, Meehan and Platts 1978).

Improper livestock grazing negatively affects bull trout by reducing

riparian vegetation, changing stream morphology and increasing soil

erosion. These alterations degrade thermal and structural habitat

conditions and water quality for bull trout, and compound the negative

impacts of human activities.

Mining has adversely affected bull trout and their habitats in

Idaho, Montana, Oregon, and Washington (Coeur d'Alene Tribe of Idaho et

al. 1991, Johnson and Schmidt 1988, Martin and Platts 1981, Platts et

al. 1993, USDA 1992, USDA 1993, WDW 1992b). Mining can degrade aquatic

systems by producing sediment and toxic heavy metals, altering water

acidity levels, and changing stream channels and flow (Esch and

Hallock, citing others).

Klamath River Population Segment

The migratory life history forms (fluvial and adfluvial) of bull

trout in the Klamath Basin have been lost because the habitat and

migratory corridors that once supported these fish have been degraded

to an unsuitable condition. This degradation appears to have been

caused primarily by the loss of riparian vegetation and water

withdrawals, but channelization of Sun Creek and a few other streams

near Crater Lake has also been blamed for the loss of migratory fish.

Land ownership and agricultural practices in the basin suggest that the

loss of riparian vegetation is due to livestock grazing, timber

harvest, and road construction. Ziller (in litt. 1992) noted that the

removal of the riparian canopy increased stream temperatures. Water

withdrawals at irrigation diversions are common in the basin, and occur

on most streams where bull trout reside (OCAFS 1993). Because these

diversions are unscreened and unregulated in regard to minimum flow

and/or maximum withdrawal, direct loss of fish has been suggested and

downstream areas have become entirely dewatered or unsuitable for bull

trout due to low water flows and associated increasing temperatures

(OCAFS 1993). These factors have rendered much of the basin unsuitable

habitat for bull trout, and have isolated small resident populations in

extreme headwater areas where suitable habitat still exists (Ziller

1992, Ratliff and Howell 1992). Irrigation, livestock grazing, timber

harvest, and road construction is expected to continue in the basin

along with the associated impacts to aquatic habitat. Based on the 1994

record, the present or threatened destruction, modification, or

curtailment of bull trout habitat or range threatens the Klamath River

distinct population segment of bull trout.

Columbia River Population Segment

Bull trout populations in the Columbia River population segment

face a number of threats from habitat degradation and passage problems.

Isaacson (1994) documented extensive habitat degradation of watersheds

in Idaho and Montana. Suitable bull trout habitat on National Forest

lands west of the Continental Divide have been impacted by land

management practices including logging, road building, and grazing.

Based on a survey of National

[[Page 32278]]

Forests reported by Isaacson (1994), a significant portion of

watersheds on the Clearwater (71 percent), Nez Perce (67 percent),

Kootenai (42 percent), Lolo (65 percent), Bitterroot (66 percent),

Flathead (44 percent), and Idaho Panhandle National Forests (64

percent) have been moderately to severely degraded. Moreover, a large

number of National Forests in Idaho and Montana do not meet existing

Forest Plan standards for woody debris, pool/riffle ratios and other

stream habitat parameters correlated with bull trout persistence

(Isaacson 1994). Only 31 percent of streams in the Lake Pend Oreille

basin meet Forest Plan standards for stream habitat attributes, and

most of these streams (52 percent) are in the most degraded category.

Such land management practices have deleterious effects on bull trout

populations. In the Flathead River drainage, decreased survival of

early life history stages was associated with increases in deposition

of fine sediments in spawning gravel (Shepard 1984a, Weaver and Fraley

1991).

High water temperature is considered to be a factor limiting bull

trout in certain Washington systems (Craig and Wissmer 1993). The

negative impacts of grazing appear to be major factors in habitat

degradation in Oregon and Idaho (USDA 1993). Grazing is identified as a

major cause of habitat degradation in 15 of 34 streams/stream reaches

supporting bull trout populations in the Clearwater River basin (USFS,

in litt., 1993). In Washington, for instance, agriculture was

identified as being one of the greatest sources of non-point source

pollution to rivers and streams (Edwards et al. 1992 in USDA 1994).

Water quality in the Yakima River system has been degraded due to

agricultural activities (WDE 1992).

Based on re-surveys of five rivers in the Lower Columbia, Sedell

and Everest (1991) documented a loss of large pools during the past 50

years due to grazing, road construction, dredge mining, agricultural

practices, and forest management. On the Middle Fork Salmon River in

Idaho, large pool density has decreased 52 percent in some tributaries.

On the Grande Ronde, Willamette, and Lewis and Clark rivers in Oregon

the concentration of large pools has decreased by 67, 41, and 60

percent, respectively. Only tributaries in the Yakima River basin in

Washington exhibited an increase (27 percent) in pool density.

Habitat degradation as the result of mining related activities in

Montana has resulted in the extinction of some populations and the

reduction of others (Thomas 1992). The upper Clark Fork above Milltown

Dam in Montana has been contaminated by high levels of arsenic,

cadmium, copper, lead, and zinc from large-scale copper mining and

mineral processing. As a result, four Superfund sites have been

designated in this area, and tests indicate that contamination has

caused substantial reductions in the number, growth, and diversity of

trout (RCG/Hagler, Bailly, Inc. 1993). Bull trout have likely been

among the fish impacted, as only a few scattered headwater populations

of bull trout currently exist. Entire drainages within the Clearwater

and Salmon River basins have been severely degraded by past gold dredge

mining practices (Esch and Hallock, no date). Mining continues in two

streams with bull trout in the North Fork Clearwater River (C.

Huntington, Clearwater Biostudies, pers. comm. 1993).

Irrigation practices restrict bull trout migrations and isolate

populations from historical mainstem habitats in the Snake, Yakima,

Walla Walla, Powder, Malheur, Grande Ronde, Umatilla, John Day, Clark

Fork, and Bitterroot rivers (ODFW 1993, Thomas 1992, WDW 1992b).

Dorratcaque (1986) documented chronic flow and passage problems on the

Lemhi River of Idaho, where a complete lack of flow has occurred during

the migration period. Over 80 percent of the annual stream flow in the

Yakima subbasin is diverted for irrigation purposes and return flows

account for 90 percent of the lower-river flow during the irrigation

season (WDE 1992). Bull trout in this subbasin are now isolated in

upper tributaries and are at high risk of extinction (WDW 1992b).

In addition to the negative effects associated with improper land

management practices, habitat fragmentation due to hydroelectric

impoundments have significantly impacted bull trout populations.

Numerous impoundments throughout the Columbia Basin have isolated

populations and altered mainstem habitat. Hydroelectric facilities such

as Albeni Falls (1952), Noxon Rapids (1958), Cabinet Gorge (1951), and

Milltown (1906) in the Clark Fork/Pend Oreille system have eliminated

or reduced adfluvial and fluvial populations (Paragamian and Ellis

1993, Pratt and Houston 1993, and Thomas 1992). Similar consequences

have occurred on the Flathead River where Kerr, Big Fork, and Hungry

Horse Dams curtail population interchange (Fraley et al. 1989). Bull

trout populations in Montana and northern Idaho are functionally

isolated from lower Columbia River populations by a number of mainstem

River impoundments including Chief Joseph and Grand Coulee Dams. The

mainstem Columbia and Snake rivers are fragmented by 11 hydroelectric

facilities. In addition, smaller impoundments are numerous throughout

the system and have isolated bull trout populations in Montana, Idaho,

Washington, and Oregon (USDA 1993). New hydropower development

continues to occur, primarily for small hydropower facilities. For

example, the Horseshoe Bend Project on the Payette River in Idaho,

would involve a diversion dam and powerhouse that could cause bull

trout migration problems and habitat losses from dewatering. Other

examples of segregation due to hydropower include three dams along the

Lewis River in southwest Washington, all built without passage

facilities.

Although bull trout are widely distributed throughout the Columbia

River population segment, individual populations are highly fragmented,

and most populations are isolated and remnant. Of those populations

where status is known and population data exist, the general trend in

this distinct population segment is declining. A few populations,

however, are considered stable or increasing, and are represented in

parts of the Swan, Deschutes, Grande Ronde, Tucannon, and Malheur River

basins. Documented habitat losses from timber harvest, grazing, mining,

and hydropower are widespread and expected to continue throughout the

distinct population segment. Based on the 1994 record, the present or

threatened destruction, modification, or curtailment of bull trout

habitat or range threatens the Columbia River distinct population

segment of bull trout.

B. Overutilization for commercial, recreational, scientific, or

educational purposes. According to the 1994 administrative record, bull

trout historically have been targeted by anglers and government

agencies who viewed the species as undesirable because of its

piscivorous habits (Bond 1992). As recently as 1990, programs were

conducted to remove bull trout through outright killing of fish,

bounties, and poisoning of waterways (Simpson and Wallace 1978, Ratliff

and Howell 1992, ODFW 1993, Newton and Pribyl 1994).

Many bull trout populations were intensely harvested prior to the

implementation of restrictive angling regulations (Brown 1992, ODFW

1993, WDW 1992b). Overharvest (both legal and illegal) can seriously

threaten populations already reduced by factors such as competition,

degraded habitat, and isolation (Fraley et al. 1989, Brown

[[Page 32279]]

1992a, Craig and Wissmar 1993). Forty-two percent of all populations

across the range were considered suppressed due to accessibility and

overharvest (USDA 1993).

In recognition of the decline of bull trout populations rangewide,

harvest regulations have become significantly restrictive in recent

years. While certain introduced fish, such as small rainbow trout, may

provide supplemental forage for large adult bull trout (Faler 1991,

Pratt 1992, ODFW 1993), introductions have been shown to increase the

risk of incidental and illegal harvest (Rode 1990, Bond 1992, WDW

1992b). Unfortunately, illegal poaching of bull trout continues and

especially threatens small populations (WDW 1992b; Pratt and Huston

1993; USDA 1993; Goetz, pers. comm. 1994, Perkinson, Kootenai National

Forest, in litt., 1994).

Electrofishing-induced injury may pose a new threat to bull trout

because of the dramatic rise in bull trout inventories using

electrofishing techniques (Horton, pers. comm. 1993). If electrofishing

is not conducted properly, bull trout may suffer mortality or injury

(Fredenberg 1992; McMichael 1993; Sharber and Carothers 1988;

Fredenberg, Fish and Wildlife Service, pers. comm. 1993).

Klamath River Population Segment

Though recreational harvest of adult bull trout likely contributed

to the historical decline of the species, harvest has been curtailed

since a regulatory ban was imposed in 1992. Because angling for other

trout species continues, OCAFS (1993) suggested that incidental

mortality may occur on bull trout in spite of their no-harvest

regulation. This claim is speculative, however, and it is not supported

in the 1994 record. As a result, the overutilization of bull trout for

commercial, recreational, scientific, or educational purposes does not

threaten the Klamath Basin population segment based on the 1994 record.

Columbia River Population Segment

Historic harvest in the range of the Columbia River population

segment likely contributed to the observed decline of bull trout. In

the past, harvest included legal recreational angling, poaching, and

directed eradication programs (Thomas 1992). Statewide angling

regulations have recently become more restrictive in an attempt to

protect bull trout throughout Montana, Idaho, Oregon and Washington.

Oregon, Idaho, and Montana have adopted much more restrictive statewide

angling regulations for harvest fisheries associated with Lake Billy

Chinook, Lake Pend Oreille, and Flathead Lake. Those areas of Oregon

where bull trout are in the most precarious situations (including the

Willamette, Hood, Malheur, Powder, and Pine rivers) are now closed to

fishing (Ratliff and Howell 1992). In an effort to protect bull trout

from recreational harvest, the Washington Department of Fish and

Wildlife has prohibited take of bull trout in eastern Washington and in

the lower Columbia River (Brown 1992). While undocumented, poaching may

still be a problem in certain areas of the Columbia River population

segment, especially for large adfluvial and fluvial adults. However,

because angling restrictions are in place and legal harvest is limited

to only a few large populations, the overutilization of bull trout for

commercial, recreational, scientific, or educational purposes in the

Columbia River population segment is not substantiated in the 1994

record.

C. Disease and predation. Disease is not believed to be a critical

factor in the long-term health and survival of bull trout populations.

Predation on juvenile bull trout by non-native fish species, such as

lake, brown, and brook trout, is a recent and potentially serious

threat to some populations (Pratt and Huston 1993, Rieman and McIntyre

1993).

Klamath River Population Segment

Exotic fish species have been introduced into Klamath Basin

streams, and either brown or brook trout reside in conjunction with

bull trout in all but one of the seven remaining populations (Ziller

1992, Ratliff and Howell 1992). The most significant threat by

introduced species to bull trout is hybridization (see section E. Other

natural or manmade factors affecting its continued existence). Although

the potential for predation prevails, no evidence in the 1994 record

suggests that predation occurs in this population segment. Neither

Ratliff and Howell (1992) or OCAFS (1993) considered predation to be a

threat to bull trout in the Klamath Basin. Based on the administrative

1994 record, disease or predation do not threaten the Klamath Basin

population segment.

Columbia River Population Segment

Little information exists for the Columbia River population segment

that implicates predation or disease as a significant factor for bull

trout decline. Introductions of non-native fish present the most

serious threat through hybridization (see section E. Other natural or

manmade factors affecting its continued existence). However, lake trout

populations have increased in Flathead Lake and resulted in the

expansion of lake trout into the Flathead River system (Vashro et al.

1992), where they may prey on emigrating juvenile bull trout (Thomas

1992; Fredenberg, pers. comm. 1994). Similarly, bull trout population

declines in Priest Lake, Idaho, appear to be correlated with the

abundance of lake trout (Mauser 1985, Pratt and Houston 1993) and may

be due to either competition or predation. Nonetheless, based on

administrative 1994 record, disease does not threaten the Columbia

River population segment and the threat posed by predation is limited

and not substantiated for the entire population segment.

D. The inadequacy of existing regulatory mechanisms. Implementation

of Federal and State laws designed to conserve fish resources or

maintain water quality has been inadequate to prevent past and ongoing

habitat degradation and population fragmentation. Deficient agency

funding, competing implementation priorities and the large multi-state/

international geographic area have contributed to this inadequacy. In

addition, conservation measures provided for in many additional

regulations are merely advisory to action agencies. Federal laws

include the Fish and Wildlife Coordination Act; National Forest

Management Act; Federal Land Policy and Management Act; Oregon and

California Act; Clean Water Act; Rivers and Harbors Act; Federal Power

Act; Pacific Northwest Electric Power Planning and Conservation Act;

and Comprehensive Environmental Response, Compensation, and Liability

Act. State laws include the Montana Stream Protection Act, Montana

Natural Streambed and Land Preservation Act, and the Washington Forest

Practices Act. In response to population declines, State fisheries

agencies throughout the range have imposed increasingly restrictive

harvest regulations for bull trout.

Klamath River Population Segment

Though historic harvest in the Klamath River basin likely

contributed to the decline of bull trout, no information is provided in

1994 record to suggest that harvest, or the inadequacy of environmental

rules and regulations now threaten bull trout. Given that legal harvest

has been stopped since 1992, the 1994 record does not document

inadequate existing regulatory mechanisms for the Klamath River

population segment.

Columbia River Population Segment

Historic harvest in the Columbia River Basin likely contributed to

the decline

[[Page 32280]]

of bull trout (Ratliff and Howell 1992, Thomas 1992). Harvest included

legal recreational angling, poaching, and directed eradication programs

(Thomas 1992). Idaho, Montana, and Oregon have since adopted much more

restrictive harvest regulations for the stronghold fisheries of Lake

Pend Oreille, Flathead Lake, and Lake Billy Chinook. Fishing seasons

are closed to the harvest of bull trout in virtually all other waters

of this distinct population segment outside of Canada. However,

implementation of Federal and State laws designed to conserve fish

resources or maintain water quality has been inadequate to prevent past

and ongoing habitat degradation and population fragmentation. Deficient

agency funding, competing implementation priorities and the large

multi-state/international geographic area have contributed to this

inadequacy. Thus, given the above and that the general trend of bull

trout populations in this distinct population segment is declining, the

1994 record suggests that existing regulatory mechanisms for the

Columbia River distinct population segment are inadequate.

E. Other natural or manmade factors affecting its continued

existence. Isolation, competition, and hybridization with introduced

species adversely impact the persistence and viability of bull trout

populations. Widespread introduction of non-native species across the

range of bull trout has frequently resulted in serious population

declines and extirpations (Bond 1992, Donald and Alger 1993, Howell and

Buchanan 1992, Leary et al. 1993, Markle 1992, Platts et al. 1993,

Pratt and Huston 1993, Rieman and McIntyre 1993, Isaacson 1994). Fish

introductions significantly affect the persistence of populations,

particularly when occurring in concert with habitat degradation and

extirpated migratory life history forms (Rieman and McIntyre 1993).

Introduced brook trout have become established throughout much of

the range of bull trout and hybridization seriously threatens the

persistence of bull trout populations (Leary et al. 1993; Markle 1992;

Rieman and McIntyre 1993; Thomas 1992, WDW 1992a and 1992b).

Hybridization results in offspring that are nearly always sterile,

eventually eliminating bull trout from a system (Leary et al. 1993).

Life history differences between the two species (brook trout mature

faster and have a higher reproductive rate) favor brook trout where

ranges overlap (Thomas 1992). This threat is exacerbated when larger,

migratory forms of bull trout have been eliminated and gene flow is

prevented by the isolation of remnant bull trout populations.

Non-native lake trout are dominant and are able to displace bull

trout where niche overlap and potential competition between the two

species is substantial (Donald and Alger 1993). In two cases,

introduced lake trout have replaced bull trout in less than 30 years

(Donald and Alger 1993). In another case, lake trout appear to be in

the process of replacing bull trout in Flathead Lake, which was

considered a stronghold for bull trout (Thomas 1992, Weaver 1993).

Non-native brown trout and bull trout are likely to be in direct

competition in numerous drainages (Platts et al. 1993, Pratt and Huston

1993, Ratliff and Howell 1992). Pratt and Huston (1993) note that brown

trout and bull trout achieve similar sizes and have overlapping

spawning seasons, which may result in disruption of bull trout redds

and competition for resources.

A variety of mechanisms are responsible for isolating bull trout

populations across their range. Isolation may occur directly, resulting

from barrier structures (e.g., dams, weirs, culverts, stream

diversions), or indirectly as a result of degraded habitat conditions

(e.g., altered thermal regimes, dewatered stream reaches,

channelization). Once isolated, bull trout populations face relatively

high probabilities of extinction due to loss of gene flow and

relatively low population size (Rieman and McIntyre 1993).

Klamath River Population Segment

Perhaps the most significant threat to the remaining bull trout

populations in the Klamath Basin is hybridization with introduced brook

trout. Where the two species reside together, bull trout abundance is

alarmingly low, and hybrids are common; only four populations exist in

the absence of brook trout and these populations are the most abundant

populations in the basin (Ratliff and Howell 1992, Ziller, 1992). Bull

trout have recently gone extinct in the Upper Sycan River and Sevenmile

Creek, which now contain only brook trout and hybrids (Ratliff and

Howell 1992). Because bull trout brook trout hybrids are

almost always sterile, the loss of the less numerous parental species

(typically bull trout) inevitably occurs (Leary et al, 1992).

Differences in life history and habitat tolerances between the species

also tend to favor brook trout.

Competition with introduced brook and brown trout particularly may

threaten bull trout in the Klamath Basin because only one of the seven

remaining populations exist in the absence of these species (Ratliff

and Howell 1992, Ziller 1992). Population declines, however, have not

been attributed to competition in the basin like they have been to

hybridization and habitat loss.

The seven remaining populations of bull trout in the Klamath Basin

are isolated from one another by degraded, unsuitable habitat. In

addition, four of these populations have a total population size of

fewer than 500 individuals (all age classes represented) (B. Hooton,

ODFW, in litt. 1993). Extinction risks increase dramatically when

isolated populations decrease in size and/or metapopulations become

further fragmented (Rieman and McIntyre 1993). In addition, the

restriction of gene flow among isolated populations compounds these

threats and reduces genetic diversity and the associated plasticity of

populations to withstand extreme environmental conditions (Rieman and

McIntyre 1993). These situations are prominent within the Klamath River

population segment. Based on the documented hybridization and human-

induced isolation described in the 1994 record, other natural or

manmade factors pose a threat to the continued existence of the Klamath

River population segment.

Columbia River Population Segment

In parts of the Columbia River Basin, non-native introductions

seriously threaten bull trout populations. Where bull trout occur with

brook trout, the threat of hybridization, loss of genetic integrity,

and production of sterile offspring is a major concern (Ratliff and

Howell 1992; Thomas 1992; Esch and Hallock, no date; USDA 1992). Forty-

five percent of the bull trout populations in Oregon evaluated by

Ratliff and Howell (1992) were considered at risk from brook trout.

Populations that are at greatest risk are resident forms occurring

predominantly in the headwater tributary reaches. Adfluvial and fluvial

bull trout appear to be at less risk (Ratliff and Howell 1992).

However, adfluvial and fluvial bull trout are in direct competition

with non-native lake trout in certain areas such as Priest Lake, Idaho

(Pratt and Houston 1993). Bull trout displacement by lake trout is of

special concern in Flathead Lake, Montana and Lake Pend Oreille, Idaho,

which have been considered strongholds for bull trout (Thomas 1992,

Weaver 1993). Based on the documented hybridization and competition

from introduced brook and lake trout described in the 1994 record,

other natural and manmade factors pose a threat to the continued

existence of the Columbia River population segment.

The Service has carefully assessed the best scientific and

commercial

[[Page 32281]]

information available in the 1994 administrative record regarding the

present and future threats facing the two distinct population segments

of bull trout. Determinations by distinct population segment follow.

Klamath River Population Segment

The trend for this distinct population segment is declining based

on the 1994 record. Only seven bull trout populations remain, which are

isolated and remnant, and occupy only a fraction of the historically

available habitat. Larger, more fecund migratory forms have essentially

been lost from the entire distinct population segment, with only small,

resident fish still existing. Imminent threats from habitat

degradation, irrigation diversions, and the presence of non-native

brook trout place this distinct population segment at a moderate to

high risk of extinction.

Documented evidence for a drastic decline in bull trout in the

Klamath River population segment was prominent in the 1994 record. None

of the seven remaining populations occupy any more than 2.5 miles of

available habitat, and no one population consists of more than 500

individuals (all year classes represented). Because the remaining

populations consist of small resident forms with low fecundity,

reproductive and natural recovery potential is extremely poor. As a

result, their likelihood of persistence in the foreseeable future is

uncertain in the absence of special protection and recovery efforts.

Based on an evaluation of the 1994 administrative record, the Klamath

River population segment is in danger of extinction throughout all or a

significant portion of its range, and, thus, this population segment

fits the definition of endangered as defined by the Act.

Columbia River Population Segment

Bull trout populations within the Columbia River population segment

have declined from historic levels and are generally considered to be

isolated and remnant (Rieman and McIntyre 1993, Thomas 1992, USDA 1993,

WDW 1992). An examination of 386 bull trout populations in this

population segment in the United States indicated that 33 percent were

declining, 15 percent stable, 3 percent secure, and 2 percent

increasing (Ratliff and Howell 1992, USDA 1993, WDW 1992). The

population status of the remaining 47 percent in the United States was

unknown, as were those populations in British Columbia in the 1994

record. Because the Service considered known documented trends within a

distinct population segment to be representative of the entire

population segment, an overall declining trend of bull trout

populations in the Columbia River basin was evident based on the 1994

administrative record.

Decrease in bull trout abundance throughout the Columbia River

population segment is evident with former stronghold populations in

Flathead Lake and Lake Pend Oreille declining. However, examples of

stable or increasing populations, such as Swan Lake and Lake Billy

Chinook, were also found in this distinct population segment. Because

of the species' wide range, scattered distribution, and diversity of

life histories in the Columbia River basin, threats from habitat

degradation, passage restriction, and non-native brook trout are

moderate for bull trout populations in this distinct population

segment. Based on the above evaluation of the 1994 administrative

record, the Columbia River population segment is likely to become

endangered within the foreseeable future throughout all or a

significant portion of its range, and, thus, this population segment

fits the definition of threatened as defined by the Act.

Critical habitat is not determinable for the two distinct

population segments of bull trout included in this proposed rule, for

reasons discussed in the ``Critical Habitat'' section of this rule.

Critical Habitat

Critical habitat is defined in section 3 of the Act as--(i) the

specific area within the geographical area occupied by a species, at

the time it is listed in accordance with the Act, on which are found

those biological features (I) essential to the conservation of the

species and (II) which may require special management considerations or

protection; and (ii) specific areas outside the geographical area

occupied by a species at the time it is listed, upon a determination

that such areas are essential for the conservation of the species.

``Conservation'' means the use of all methods and procedures needed to

bring the species to the point at which listing under the Act is no

longer necessary.

Section 4(a)(3) of the Act, as amended, and implementing

regulations (50 CFR 424.12) require that, to the maximum extent prudent

and determinable, the Secretary designate critical habitat at the time

the species is determined to be endangered or threatened. Service

regulations (50 CFR 424.12(a)) state that critical habitat is not

determinable if information sufficient to perform required analysis of

impacts of the designation is lacking or if the biological needs of the

species are not sufficiently well known to permit identification of an

area as critical habitat. Section 4(b)(2) of the Act requires the

Service to consider economic and other relevant impacts of designating

a particular area as critical habitat on the basis of the best

scientific data available. The Secretary may exclude any area from

critical habitat if he determines that the benefits of such exclusion

outweigh the conservation benefits, unless to do such would result in

the extinction of the species.

The Service finds that the determination of critical habitat is not

determinable for these distinct population segments based on the 1994

administrative record. When a ``not determinable'' finding is made, the

Service must, within 2 years of the publication date of the original

proposed rule, designate critical habitat, unless the designation is

found to be not prudent. The Service reached this conclusion because

the biological needs of the species in the two population segments are

not sufficiently well known to permit identification of areas as

critical habitat in the 1994 administrative record. Specifically, no

information was available in the 1994 record on the number of

individuals required for a viable population throughout the distinct

population segment. In addition, the extent of habitat required for

recovery of these fish had not been identified. This information is

considered essential for determining critical habitat for these

population segments. Therefore, the Service finds that designation of

critical habitat for these species is not determinable at this time.

Available Conservation Measures

Conservation measures provided to species listed as endangered or

threatened under the Endangered Species Act include recognition,

recovery actions, requirements for Federal protection, and prohibitions

against certain activities. Recognition through listing encourages and

results in conservation actions by Federal, State, and private

agencies, groups, and individuals. The Act provides for possible land

acquisition and cooperation with the State and requires that recovery

actions be carried out for all listed species. The protection required

of Federal agencies and the prohibitions against taking and harm are

discussed, in part, below.

Section 7(a) of the Act, as amended, requires Federal agencies to

evaluate their actions with respect to any species that is proposed or

listed as endangered or threatened and with respect to its critical

habitat, if any is being

[[Page 32282]]

designated. Regulations implementing this interagency cooperation

provision of the Act are codified at 50 CFR Part 402. Section 7(a)(4)

requires Federal agencies to confer with the Service on any action that

is likely to jeopardize the continued existence of a species proposed

for listing or result in destruction or adverse modification of

proposed critical habitat. If a species is listed subsequently, section

7(a)(2) requires Federal agencies to insure that activities they

authorize, fund, or carry out are not likely to jeopardize the

continued existence of a listed species or to destroy or adversely

modify its critical habitat. If a Federal action may affect a listed

species or its critical habitat, the responsible Federal agency must

enter into formal consultation with the Service.

The Klamath River and Columbia River bull trout population segments

occur on lands administered by the U.S. Forest Service and Bureau of

Land Management (BLM); various State-owned properties in Oregon,

Washington, Idaho and Montana; and private lands. Federal agency

actions that may require conference and/or consultation as described in

the preceding paragraph include Army Corps of Engineers (Corps)

involvement in projects such as the construction of roads and bridges,

and the permitting of wetland filling and dredging projects subject to

section 404 of the Clean Water Act (33 U.S.C. 1344 et seq.); Federal

Energy Regulatory Commission licensed hydropower projects authorized

under the Federal Power Act; Forest Service and BLM timber and grazing

management activities; Environmental Protection Agency authorized

discharges under the National Pollutant Discharge System of the Clean

Water Act; and U.S. Housing and Urban Development projects.

The Act and its implementing regulations found at 50 CFR 17.21 and

17.31 set forth a series of general trade prohibitions and exceptions

that apply to all endangered and threatened wildlife, respectively.

These prohibitions, in part, make it illegal for any person subject to

the jurisdiction of the United States to take (includes harass, harm,

pursue, hunt, shoot, wound, kill, trap, or collect; or attempt any of

these), import or export, ship in interstate commerce in the course of

commercial activity, or sell or offer for sale in interstate or foreign

commerce any listed species. It is also illegal to possess, sell,

deliver, carry, transport, or ship any such wildlife that has been

taken illegally. Certain exceptions apply to agents of the Service and

State conservation agencies.

Permits may be issued to carry out otherwise prohibited activities

involving endangered and threatened wildlife under certain

circumstances. Regulations governing permits are at 50 CFR 17.22, 17.23

and 17.32. Such permits are available for scientific purposes, to

enhance the propagation or survival of the species, and/or for

incidental take in connection with otherwise lawful activities. For

threatened species, permits are also available for zoological

exhibition, educational purposes, or special purposes consistent with

the purpose of the Act.

It is the policy of the Service published in the Federal Register

on July 1, 1994, (59 FR 34272) to identify to the maximum extent

practicable at the time a species is listed those activities that would

or would not constitute a violation of section 9 of the Act. The intent

of this policy is to increase public awareness of the effect of this

listing on proposed and ongoing activities within the species' range.

The Service believes the following actions would not be likely to

result in a violation of section 9:

(1) Actions that may affect bull trout in the Klamath and Columbia

River basins and are authorized, funded or carried out by a Federal

agency when the action is conducted in accordance with an incidental

take statement issued by the Service pursuant to section 7 of the Act;

(2) Possession of Columbia River basin bull trout caught legally in

accordance with state fishing regulations.

With respect to both the Klamath River and Columbia River bull

trout population segments, the following actions likely would be

considered a violation of section 9:

(1) Take of bull trout without a permit, which includes harassing,

harming, pursuing, hunting, shooting, wounding, killing, trapping,

capturing, or collecting, or attempting any of these actions, except in

accordance with applicable State fish and wildlife conservation laws

and regulations within the Columbia River bull trout population

segment;

(2) Possess, sell, deliver, carry, transport, or ship illegally

taken bull trout;

(3) Interstate and foreign commerce (commerce across state and

international boundaries) and import/export (as discussed earlier in

this section);

(4) Introduction of non-native fish species that compete or

hybridize with, or prey on bull trout;

(5) Destruction or alteration of bull trout habitat by dredging,

channelization, diversion, in-stream vehicle operation or rock removal,

or other activities that result in the destruction or significant

degradation of cover, channel stability, substrate composition,

temperature, and migratory corridors used by the species for foraging,

cover, migration, and spawning;

(6) Discharges or dumping of toxic chemicals, silt, or other

pollutants into waters supporting bull trout that result in death or

injury of the species; and

(7) Destruction or alteration of riparian or lakeshore habitat and

adjoining uplands of waters supporting bull trout by timber harvest,

grazing, mining, hydropower development, or other developmental

activities that result in destruction or significant degradation of

cover, channel stability, substrate composition, temperature, and

migratory corridors used by the species for foraging, cover, migration,

and spawning.

Questions regarding whether specific activities may constitute a

violation of section 9 should be directed to the Field Supervisor of

the Service's Snake River Basin Office (see ADDRESSES section).

Requests for copies of the regulations concerning listed animals and

inquiries regarding prohibitions and permits may be addressed to the

U.S. Fish and Wildlife Service, Endangered Species Permits, 911 NE.

11th Avenue, Portland, Oregon 97232-4181 (telephone 503/231-6241;

facsimile 503/231-6243).

Special Rule

Section 4(d) of the Act provides authority for the Service to

promulgate special rules for threatened species that would relax the

prohibition against taking. In this case, the Service proposes a

special rule for the Columbia River bull trout distinct population

segment (see Proposed Regulations Promulgation section). The Service

recognizes that, based on the 1994 administrative record, statewide

angling regulations have become more restrictive in an attempt to

protect bull trout throughout Montana, Idaho, Oregon, and Washington.

The Service intends to continue to work with the States in developing

management plans and agreements with the objective of recovery and

eventual delisting of the Columbia River bull trout distinct population

segment. The Service is consequently proposing a special rule under

section 4(d) that offers additional management flexibility for this

population segment. The special rule would allow for take of bull trout

within the Columbia River population segment

[[Page 32283]]

when it is in accordance with applicable State fish and wildlife

conservation laws and regulations. The Service believes that a special

rule of this nature will benefit the Columbia River distinct population

segment of bull trout, and that the rule would satisfy the requirement

under section 4(d) that regulation applied to threatened species embody

those measures deemed necessary and advisable to provide for the

conservation of the population segment in question.

Public Comments Solicited

The Service intends that any final action resulting from this

proposal will be as accurate and as effective as possible. Therefore,

comments or suggestions from the public, other concerned governmental

agencies, the scientific community, industry, or any other interested

party concerning this proposed rule are hereby solicited. Comments

particularly are sought concerning:

(1) Biological, commercial trade, or other relevant data concerning

threat (or lack thereof) to these two population segments;

(2) The location of any additional populations of the two segments

and the reasons why any habitat should or should not be determined to

be critical habitat as provided by section 4 of the Act;

(3) Additional and updated information concerning the range,

distribution, and population size of the two segments;

(4) Current or planned activities in the subject area and their

possible impacts on the two population segments; and

(5) Promulgation of the special rule.

The final decision on this proposal will take into consideration

the comments and any additional information received by the Service,

and such communications may lead to a final determination that differs

from this proposal. In addition, the Service will consider significant

new information on bull trout received since the close of the 1994

administrative record. A list of significant references concerning bull

trout that have become available since the close of the 1994 record may

be obtained upon request from the Snake River Basin Field Office (see

ADDRESSES above).

The Endangered Species Act provides for at least one public hearing

on this proposal, if requested. However, given the high likelihood of

several requests throughout the range of both population segments, the

Service has scheduled five hearings in advance of any request. The

hearings are scheduled for Portland, Oregon, on July 1, 1997; Spokane,

Washington, on July 8, 1997; Missoula, Montana, on July 10, 1997;

Klamath Falls, Oregon, on July 15, 1997; and Boise, Idaho, on July 17,

1997. For additional information on public hearings, see the DATES

section.

National Environmental Policy Act

The Fish and Wildlife Service has determined that Environmental

Assessments and Environmental Impact Statements, as defined under the

authority of the National Environmental Policy Act of 1969, need not be

prepared in connection with regulations adopted pursuant to section

4(a) of the Endangered Species Act of 1973, as amended. A notice

outlining the Service's reasons for this determination was published in

the Federal Register on October 25, 1983 (48 FR 49244).

Required Determinations

The Service has examined this regulation under the Paperwork

Reduction Act of 1995 and found it to contain no information collection

requirements.

References Cited

A complete list of all references cited herein is available upon

request from the Snake River Basin Field Office (see ADDRESSES above).

Author: The primary authors of this proposed rule are Don Sundeen

and Jim Bartel, Regional Office, Portland, Oregon.

List of Subjects in 50 CFR Part 17

Endangered and threatened species, Exports, Imports, Reporting and

recordkeeping requirements, and Transportation.

Proposed Regulations Promulgation

PART 17--[AMENDED]

Accordingly, part 17, subchapter B of Chapter I, Title 50 of the

Code of Federal Regulations, is proposed to be amended as set forth

below:

1. The authority citation for part 17 continues to read as follows:

Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.

4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

2. Amend Sec. 17.11(h) by adding the following, in alphabetical

order under Fishes, to the List of Endangered and Threatened Wildlife:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *

(h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------

Species Vertebrate

------------------------------------------------------ population where Critical

Historic range endangered or Status When listed habitat Special rules

Common name Scientific name threatened

--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *

Fishes

* * * * * * *

Trout, bull..................... Salvelinus U.S.A. (OR)....... Klamath River..... E NA NA

confluentus.

Do.......................... ......do........... U.S.A. (ID, MT, Columbia River.... T NA 17.44(v)

OR, WA) Canada.

* * * * * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------

3. Amend Sec. 17.44 by adding paragraph (v) to read as follows:

Sec. 17.44 Special rule--fishes.

* * * * *

(v) Bull trout (Salvelinus confluentus), Columbia River population

(1) No person shall take this species, except in accordance with

applicable State fish and wildlife conservation laws and regulations.

(2) Any violation of applicable State fish and wildlife

conservation laws or regulations with respect to the taking of this

species is also a violation of the Endangered Species Act.

(3) No person shall possess, sell, deliver, carry, transport, ship,

import, or export, any means whatsoever, any such

[[Page 32284]]

species taken in violation of these regulations or in violation of

applicable State fish and game laws and regulations.

(4) It is unlawful for any person to attempt to commit, solicit

another to commit, or cause to be committed, any offense defined in

paragraphs (v) (1) through (3) of this section.

Dated: June 9, 1997.

William Leary,

Acting Deputy Assistant Secretary for Fish and Wildlife and Parks.

[FR Doc. 97-15584 Filed 6-12-97; 8:45 am]

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