[Federal Register: March 11, 2003 (Volume 68, Number 47)]
[Page 11574-11579]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

Endangered and Threatened Wildlife and Plants; 12-month Finding 
for a Petition To List the Lower Kootenai River Burbot (Lota lota) as 
Threatened or Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.


SUMMARY: We, the Fish and Wildlife Service (Service), announce a 12-
month finding for a petition to list lower Kootenai River burbot (Lota 
lota), in accordance with the Endangered Species Act of 1973, as 
amended (Act). After reviewing the best available scientific and 
commercial information available, we find that the petitioned action is 
not warranted, because the petitioned entity is not a distinct 
population segment (DPS) and, therefore, is not a listable entity. We 
ask the public to submit to us any new information that becomes 
available concerning the status of or threats to this species. This 
information will help

[[Page 11575]]

us monitor and encourage the conservation of this species.

DATES: The finding announced in this document was made on March 3, 
2003. Although further listing action will not result from this 
finding, we request that you submit new information for this species 
concerning status or threats whenever it becomes available.

ADDRESSES: You may send data, information, or questions concerning this 
finding to the Supervisor, Upper Columbia Fish and Wildlife Office, 
U.S. Fish and Wildlife Service, 11103 E. Montgomery Drive, Spokane, WA 
99206. This 12-month finding, supporting data, and comments are 
available for public inspection, by appointment, during normal business 
hours at the above address.

FOR FURTHER INFORMATION CONTACT: Scott Deeds at the above address 
(telephone 509/893-8007). Information regarding this finding is 
available in alternate formats upon request.



    Section 4(b)(3)(B) of the Endangered Species Act of 1973, as 
amended (Act) (16 U.S.C. 1531 et seq.), requires that, for any petition 
seeking to revise the List of Threatened and Endangered Species that 
contains substantial scientific or commercial information that listing 
may be warranted, we make a finding within 12 months of the date of 
receipt on whether the petitioned action is (a) not warranted, (b) 
warranted, or (c) warranted but precluded by other pending proposals. 
Such 12-month findings are to be published promptly in the Federal 
    We have made a 12-month finding on a petition to list the lower 
Kootenai River burbot (Lota lota). The petition, dated February 2, 
2000, was submitted by American Wildlands and the Idaho Conservation 
League and was received on February 7, 2000. The petition requests the 
emergency listing of Kootenai River burbot in Idaho as endangered and 
designation of critical habitat concurrent with the listing. On 
September 28, 2001, we published a 90-day finding for lower Kootenai 
River burbot in the Federal Register (66 FR 49608). We found that the 
petition presented substantial information indicating that listing may 
be warranted. This 12-month finding is made in accordance with a 
judicially approved stipulated settlement agreement that requires us to 
complete a finding by March 1, 2003 (American Wildlands and Idaho 
Conservation League v. Badgley, Williams, and Norton, Case No. CV 02-
00118BR). This notice constitutes the 12-month finding for the February 
7, 2000, petition.
    Burbot, also referred to as eelpout, layer, or ling, are a cold-
water, bottom-dwelling fish species and are the only freshwater member 
of the otherwise marine cod family (Gadidae). Burbot are extremely 
elongate or eel-like. Back body coloration is with marbled and ranges 
from dark olive to brown, contrasting with brown or black. The sides of 
the body are lighter than the back, and the belly is yellowish white 
(Simpson and Wallace 1982). Burbot have a distinguishing single slender 
barbel on the chin. Burbot may reach 1 meter (39.4 inches) in length, 
can weigh up to about 8 kilograms (17.6 pounds), and have a life 
expectancy up to 20 years (McPhail and Paragamian 2000).
    Most information suggests that river-spawning burbot prefer low-
velocity areas in main channels or in side channels behind deposition 
bars, with the preferred substrate consisting of fine gravel, sand, and 
even fine silt (Fabricius 1954 in McPhail and Paragamian 2000; McPail 
and Paragamian 2000). Spawning is also known to occur in small 
tributary streams and is generally believed to take place at night 
(Simpson and Wallace 1982; McPhail and Paragamian 2000).
    Female burbot are larger than males and, depending on their size, 
may produce between 50,000 and 1,500,000 eggs each per spawn (Simpson 
and Wallace 1982). Burbot are known to occur as annual or alternating 
year spawners (Arndt and Hutchinson 2000; Evenson 2000). Male burbot 
typically reach sexual maturity in 3 to 4 years, with females maturing 
in 4 to 5 years (Bonar et al. 1997; Arndt and Hutchison 2000; Eveson 
2000). During spawning, burbot typically collect in a large mass 
referred to as a spawning ball, with one or more females in the center 
surrounded by many males (Simpson and Wallace 1982; McPhail and 
Paragamian 2000). There is no site preparation during spawning, and 
eggs are broadcast into the water column well above the substrate. The 
eggs are semibuoyant and eventually settle into cracks in the 
substrate. Newly hatched burbot drift passively in open water until 
they develop the ability to swim (McPhail and Paragamian 2000). Young 
burbot initially select shoreline areas among rocks and debris for 
feeding and habitat security.
    Burbot prefer cold water and, during summer months, move to the 
hypolimnion (lower zone of a thermally stratified lake) areas of lakes 
or deep water pools of large rivers (Simpson and Wallace 1982). Feeding 
is mostly done at night, with adult burbot feeding almost exclusively 
on a fish diet. Young burbot feed on aquatic organisms such as insects, 
amphipods, snails, and small fish (Simpson and Wallace 1982). Burbot 
are most active in the winter, during which some populations move great 
distances to spawn, and are rather sedentary during the non-spawning 
    The geographic range of burbot is circumpolar and extends in an 
almost continuous distribution from the British Isles eastward across 
Europe and Asia to the Bering Strait (Berg 1949 in McPhail and 
Paragamian 2000). On the North America side of the Bering Strait, 
burbot range eastward from the Seward Peninsula in Alaska (McPhail and 
Lindsey 1970 in McPhail and Paragamian 2000) to New Brunswick on the 
Atlantic coast (Scott and Crossman 1973).
    Burbot were first described in Europe by Linnaeus in 1758 (American 
Fisheries Society 1991). Burbot in North America, known as Lota 
lacustris (Walbaum), were originally considered to be a separate 
species from those in Europe, known as Lota lota (Linnaeus) (McPhail 
and Paragamian 2000). Gunther (1862 in McPhail and Paragamian 2000) 
later reduced all burbot to a single widespread species. Hubbs and 
Shultz (1941 in McPhail and Paragamian 2000), then argued on the basis 
of morphological differences, that at least three subspecies existed: 
Lota lota lota in Europe and most of Siberia; Lota lota lacustris (also 
referred to as Lota lota maculosa) in eastern North America; and a new 
subspecies, Lota lota leptura, in northwestern North America and 
eastern Siberia. Pivnicka (1970 in Van Houdt and Volckaert in draft 
2002) performed additional morphological analyses of European burbot 
populations and determined these were apparently the same as the Lota 
lota maculosa form in North America. Pivnicka, therefore, concluded 
that burbot include two distinct forms: Lota lota lota, which occurs 
from the Volga River system throughout Siberia and Alaska to the 
Mackenzie River system in Canada, and the populations in the Elbe and 
Danube River, which lived peripherally to this subspecies; and Lota 
lota maculosa, which occurs in southernmost Canada, the United States, 
and western Europe. However, many recent authors have not used this 
subspecies designation and only recognize burbot to the species level 
(McPhail and Paragamian 2000).
    Most species whose preglacial ranges were fragmented by glaciation 
show geographic patterns in morphology that suggest survival in 
multiple refugia

[[Page 11576]]

(McPhail and Lindsey 1970 in McPhail and Paragamian 2000). This 
interpretation is supported by recent molecular studies (Taylor and 
Dodson 1984; Billington and Hebert 1988; Grewe and Hebert 1988; 
Bernatchez and Dodson 1991; all in McPhail and Paragamian 2000). Chen 
(1969 in McPhail and Paragamian 2000) demonstrated that burbot from the 
interior of Alaska (Hubbs and Schultz's Lota lota leptura) consistently 
differ in a number of morphological traits from burbot found elsewhere 
in North America. These findings, coupled with past morphological 
studies, suggest that variation in Lota lota has geographic patterning 
and, consequently, treating all burbot as a single entity may be 
inappropriate (McPhail and Paragamian 2000).
    In order to clarify the genetic variation of burbot throughout 
their wide-ranging distribution, researchers from Belgium initiated a 
study to test the many hypotheses related to burbot phylogeography. The 
mitochondrial cytochrome b from 41 populations (18 in North America and 
23 in Eurasia) of burbot was sequenced (Van Houdt and Volckaert in 
draft 2002). Their study observed two distinct phylogroups within the 
genus Lota; a palearctic group distributed from Europe to Northern 
Canada, and a neararctic group in the remaining parts of North America, 
with both groups co-occurring in the Great Slave Lakes, Northwest 
Territories. The distribution pattern of the palearctic group is nearly 
congruent to that of the subspecies designation previously discussed as 
Lota lota lota (Van Houdt and Volckaert in draft 2002). However, the 
genetic analyses does not support including burbot that occur in 
western Europe in the subspecies Lota lota maculosa, as previously 
concluded by Pivnicka. Therefore, the neararctic group of burbot only 
occur in a portion of North America and are designated as Lota lota 
maculosa (Van Houdt and Volckaert in draft 2002). Within the neararctic 
phylogroup, three different clades (taxonomic groupings of organisms 
that share common ancestry) were observed, the presence of which 
supports the suggested glacial refugia hypothesis for burbot in North 
America. The three clades are referred to as the Pacific clade, the 
Missouri clade, and the Mississippi clade (Van Houdt and Volckaert in 
draft 2002).
    Further, Van Houdt (pers. comm., 2002) indicated that burbot in the 
lower Kootenai River (the lone area sampled from the Pacific clade) are 
genetically distinct from burbot in the other clades in North America, 
as well as being genetically distinct from the palearctic group of 
burbot that occur in northern Canada, Alaska, Europe, and Asia (Van 
Houdt and Volckaert in draft 2002). However, this distinction was based 
on a small sample size and is only an indication of the existence of a 
separate glacial race (Van Houdt, pers. comm., 2002). Furthermore, we 
have no evidence that the genetic profile of lower Kootenai River 
burbot is unique relative to other burbot in the neararctic range. It 
should also be noted that the results of this research do not include 
samples from all major drainage basins in North America, and that a 
detailed phylogeographic analysis that determines exact distribution of 
each glacial race is needed to gain insight with regard to the 
evolutionary relationship of burbot throughout the neararctic region.
    Considering these findings and past morphological findings for 
burbot that suggest divergence, we determined that recognizing the two 
subspecies Lota lota maculosa and Lota lota lota for this finding is 
appropriate. We therefore evaluated lower Kootenai River burbot as they 
compare to other burbot in the neararctic region or to Lota lota 
    Burbot that occur in the Kootenai River basin exhibit three life 
history strategies in several isolated groups. The first life history 
strategy is represented by the lower Kootenai River burbot population, 
which spends a portion of its life in the South Arm of Kootenay Lake, 
British Columbia, and then migrates up the Kootenai River during the 
winter months to spawn in the mainstem river or tributary streams in 
British Columbia or Idaho (adfluvial life form). The second life 
history strategy is represented by burbot occurring further upstream in 
the Kootenai River above Kootenai Falls, which have a fluvial 
(riverine) life history (Paragamian et al. 1999). That is, they migrate 
within the river and to tributary streams for spawning. We also 
considered burbot that occur in Lake Koocanusa (a reservoir) to be 
fluvial, because they evolved with a fluvial life history prior to the 
construction of Libby Dam. We considered this population to be fluvial 
because it is currently unclear how readily burbot populations adopt a 
different life history strategy when faced with changing environmental 
conditions, and we did not believe it was appropriate to compare 
naturally occurring adfluvial populations of burbot to burbot that now 
have some adfluvial characteristics as the result of a human-created 
reservoir. The third life history strategy is represented by the only 
known lacustrine (spending entire life cycle in the lake) population in 
Kootenay Lake, which occurs in the North Arm of Kootenay Lake (Spence 
1999). Prior to dramatic declines of burbot in Kootenay Lake, a 
population was believed to have spawned at the inlet of the West Arm of 
Kootenay Lake, but this population has completely collapsed and is now 
believed to be extirpated (Spence 1999; Baxter et al. 2002; Colin 
Spence, MWLAP, pers. comm., 2001; Paragamian, pers. comm., 2000).
    Lower Kootenai River burbot spawn during the winter months, and 
under natural conditions (pre-dam), spawning occurs under ice at 
temperatures near or below 1 [deg]C (34 [deg]F) (Paragamian et al. 
2000; Simpson and Wallace 1982). They generally begin migrating up the 
Kootenai River in November and travel as far as 120 kilometers (km) (75 
miles (mi)) to traditional spawning sites (Paragamian 2000). Spawning 
commences in late January and continues through early February and 
lasts for only 2 to 3 weeks, as both gamete (egg and sperm) maturation 
and arrival to spawning sites are highly synchronous (Paragamian 2000; 
Kozfkay and Paragamian 2002; Arndt and Hutchison 2000; Eveson 2000).
    The lower Kootenai River once supported a significant number of 
burbot, which provided a very important winter fishery to the region. 
Declines were first documented in the burbot fishery around 1960, but 
numbers were still considered stable into the early 1970s. However, 
within only a few years, a dramatic decline in the burbot population 
was documented. Despite numerous fishing regulations implemented to 
reduce threats to burbot, their numbers continued to decline almost to 
extirpation, and the fishery was closed to fishing in the early 1990s. 
Based on data collected from the autumn of 1995 through the spring of 
2000, the population is estimated to consist of roughly 540 adults 
(Kozfkay and Paragamian 2002).
    Under the Act, we must consider for listing any species, 
subspecies, or, for vertebrates, any distinct vertebrate population 
segment (DPS) of these taxa if sufficient information exists to 
indicate that such action may be warranted. To implement the measures 
prescribed by the Act, we, along with the National Marine Fisheries 
Service, developed a joint policy that addresses the recognition of DPS 
for potential listing actions (61 FR 4722). The policy allows for a 
more refined application of the Act that better reflects the biological 
needs of the taxon being considered, and avoids the inclusion of 
entities that do not require its protective measures.

[[Page 11577]]

    The petitioners requested listing of the Kootenai River burbot as 
an endangered species throughout its range in the Kootenai River and 
spawning tributaries in Idaho, on the basis of threats to the 
population and its potential isolation from the remainder of the taxon. 
We considered this request because, while we do not base listing 
decisions on political subdivisions other than international 
boundaries, we must consider for listing under the Act any population 
of vertebrate taxa (species or subspecies) if it may represent a DPS. 
In our 90-day administrative finding for the subject petition (66 FR 
49608, September 28, 2001), we recognized that burbot in Idaho are part 
of a transboundary population, spending a portion of their life cycle 
in the South Arm of Kootenay Lake and the lower Kootenai River in 
British Columbia. In addition, the available information indicated that 
this population segment is separated behaviorally from the only other 
burbot population remaining in Kootenay Lake's North Arm, primarily 
because of the populations' to their differing life history strategies. 
Finally, we recognized that lower Kootenai River burbot do not use the 
Kootenai River in the segment that runs from a point upstream from 
approximately Bonners Ferry, Idaho, to just below Kootenai Falls in 
Montana, because of the presence of naturally unsuitable habitats. 
Therefore, the geographic area considered for our status review, and 
addressed by the following DPS analysis, includes the South Arm of 
Kootenay Lake and the lower Kootenai River from its mouth upstream to 
Bonners Ferry, Idaho.
    In accordance with our DPS policy (61 FR 4722), we use two elements 
to assess whether a population segment under consideration for listing 
may be recognized as a DPS. The elements are (1) the population 
segment's discreteness from the remainder of the species to which it 
belongs and (2) the significance of the population segment to the 
species to which it belongs.


    Discreteness refers to the separation of a population segment from 
other members of the taxon based on either (1) physical, physiological, 
ecological, or behavioral factors or (2) international boundaries that 
result in significant differences in control of exploitation, habitat 
management, conservation status, or regulatory mechanisms.
    The lower Kootenai River burbot have been historically isolated 
from the burbot population within the upper Kootenai River by natural 
barriers, which consist of (1) a narrow canyon with a higher gradient 
that causes an increased water velocity from approximately Bonners 
Ferry (river km (rkm) 246 (river mi (rm) 153)) to Kootenai Falls (rkm 
310 (rm 193)) and (2) the Kootenai Falls themselves. Downstream 
movement by burbot over Kootenai Falls is possible; however, none of 
the more than 400 burbot tagged in Montana above Kootenai Falls have 
been recaptured downstream in Idaho or British Columbia (Paragamian et 
al. 1999). In contrast, 40 of the 266 burbot tagged in the lower 
Kootenai River have been recaptured in the same sampling areas (Diane 
Wakkinen, Idaho Department of Fish and Game, pers. comm., 2002). While 
not conclusive, if tagged burbot from Montana moved downstream over 
Kootenai Falls and into the lower Kootenai River, we expect that they 
would also be recaptured. In addition, isolation of lower Kootenai 
River burbot from the population above Kootenai Falls is further 
supported by recent genetic analyses that indicate these two 
populations differ genetically (Paragamian et al. 1999). Even so, our 
DPS policy does not require absolute reproductive isolation as a 
prerequisite to recognizing a DPS. Therefore, even if a low level of 
genetic exchange existed between burbot populations within the Kootenai 
River basin, it would not necessarily preclude a determination of 
    The available information also indicates that lower Kootenai River 
burbot are behaviorally different from other burbot populations in the 
Kootenai River basin due to their adfluvial life history strategy 
(Northcote 1973; Paragamian et al. 1999). The only other known 
remaining burbot reproduction that occurs within Kootenay Lake is from 
the remnant lacustrine population in the North Arm (Spence 1999). While 
mixing of the lacustrine fish and the adfluvial fish may have occurred 
in the past, the available information suggests that these two burbot 
populations do not currently interact (Paragamian, pers. comm., 2000; 
Spence 1999). Telemetry studies of lower Kootenai River burbot indicate 
that these fish primarily use the delta area near the mouth of the 
Kootenai River, and no fish have been tracked moving as far north as 
the West Arm of Kootenay Lake. In addition, telemetry studies of 
lacustrine burbot indicate that these fish do not distribute throughout 
the lake, but stay within the area of the North Arm (Paragamian, pers. 
comm., 2000; Spence 1999).
    Spawning time for the lacustrine form of burbot in the North Arm of 
Kootenay Lake is approximately 1 month later than the adfluvial form in 
the lower Kootenai River (Spence 1999; Paragamian 2000; Kozfkay and 
Paragamian 2002). In addition, the burbot that previously occurred in 
the West Arm of Kootenay Lake were believed to have commenced spawning 
in April, and spawning may have continued from mid-May to mid-June 
(Martin 1976 in Redfish Consulting Ltd 1998; Martin 1977 in McPhail and 
Paragamian 2000). Because both gamete maturation and arrival at 
spawning sites are known to be highly synchronous in burbot (Arndt and 
Hutchison 2000; Evenson 2000), it is likely that the disparity in 
spawning periods between the various populations effectively isolates 
them reproductively from one another.
    Finally, with regard to the remainder of the subspecies' range, 
Kootenai Falls in Montana forms an upstream barrier to burbot movement, 
while Bonnington Falls in British Columbia, which is downstream from 
Kootenay Lake and above the confluence with the Columbia River, forms a 
downstream barrier. These two barriers have been in place since at 
least the last period of glaciation (roughly 10,000 years before 
    On the basis of available information, we conclude that the lower 
Kootenai River burbot is discrete from other populations of the same 
taxon as a consequence of physical, ecological, and behavioral factors. 
Therefore, we considered the potential significance of this discrete 
population to the remainder of the taxon.


    Under our DPS policy, once we have determined that a population 
segment is discrete, we consider its biological and ecological 
significance to the larger taxon to which it belongs. This 
consideration may include, but is not limited to: (1) Evidence of the 
persistence of the discrete population segment in an ecological setting 
that is unique for the taxon; (2) evidence that loss of the population 
segment would result in a significant gap in the range of the taxon; 
(3) evidence that the population segment represents the only surviving 
natural occurrence of a taxon that may be more abundant elsewhere as an 
introduced population outside its historic range; and (4) evidence that 
the discrete population segment differs markedly in its genetic 
characteristics from other populations of the species.
    As previously discussed, burbot distribution is circumpolar, and 
burbot are well distributed in North America and northern Eurasia. The 
species' range in North America includes the majority

[[Page 11578]]

of mainland Canada, Alaska, and many of the contiguous northern United 
States. While burbot in North America (Lota lacustris, Walbaum) were 
originally considered a separate species from those in Europe (Lota 
lota, Linnaeus), they have since been reduced to a single species 
throughout their range. However, the available information supports the 
recognition of two distinct lineages, or subspecies, which are: the 
palearctic group of northern Canada, Alaska, and Eurasia (Lota lota 
lota), and the neararctic group in the remainder of North America (Lota 
lota maculosa), which includes the lower Kootenai River burbot. On the 
basis of available information, we considered the following factors 
with regard to the potential significance of the lower Kootenai River 
burbot to the remainder of the nearactic subspecies (Lota lota 
    Ecological Setting: Neararctic burbot occupy numerous and varied 
lake, riverine, and tributary systems throughout their distribution in 
the northern United States and Canada. At the commencement of our 
status review for the subject petition, very little information was 
available regarding the potential uniqueness or unusual nature of the 
ecological setting occupied by lower Kootenai River burbot in relation 
to the remainder of the neararctic region. In addition, little such 
information has since been provided or otherwise obtained during the 
course of our status review. The petitioners assert that the Kootenai 
River population of burbot exists in a unique and unusual ecological 
setting because two genetically distinct populations are in the same 
river: those that occur in the lower Kootenai River and those that 
occur in the Kootenai River above Kootenai Falls. However, genetic 
differences can occur in the absence of unique or unusual ecological 
settings, and the available information does not indicate that any 
unique or unusual ecological features have contributed to the genetic 
differentiation that may be occurring in these burbot. Furthermore, no 
information is available to indicate that having two genetically 
distinct populations in the same river basin is unique for this 
    The petitioners further assert that the loss of these burbot would 
be a loss of a rare population at the southern edge of the species' 
range and that other Columbia River burbot populations may likewise be 
at risk of extirpation. We disagree based on the information currently 
available. First, populations of burbot are still found in Indiana, 
Kentucky, Ohio, Michigan, Minnesota, South Dakota, Wisconsin, and 
Wyoming, all of which also represent the southern extent of the 
species' distribution. Second, currently available information is not 
sufficient to enable us to determine if other burbot populations within 
the Columbia River system may be at risk of extirpation.
    On the basis of available information, we conclude that burbot 
likely occupy a wide variety of habitats throughout their range, and 
that there are no indications of any unique or unusual ecological 
features within the lower Kootenai River basin. Therefore, we do not 
currently consider the ecological setting occupied by the discrete 
population of burbot within the lower Kootenai River as significant to 
the remainder of the taxon.
    Significant Gap in Range: Loss of the lower Kootenai River burbot, 
as compared to burbot throughout the remainder of the neararctic 
region, would mean the loss of less than 1 percent of the entire range 
of the taxon. In addition, when we consider either the historic or 
current distribution of lower Kootenai River burbot, we determine that 
loss of this population segment would not isolate one or more otherwise 
contiguous populations of burbot within the Kootenai River basin. On 
the basis of the above information, we conclude that loss of the lower 
Kootenai River burbot would not represent a significant gap in the 
range of the taxon.
    Genetic Characteristics: We reviewed three available studies, in 
various stages of completion, that address the genetic differentiation 
of burbot across portions of the taxon's range. One investigated the 
genetic characteristics of burbot populations within the Kootenai River 
basin (Paragamian et al. 1998), a second addressed genetic 
differentiation west and east of the continental divide (Dalby, pers. 
comm., 2002), and a third addressed genetic differentiation of burbot 
populations across the entire range of the species, and was conducted 
to help clarify the species' phylogenetic history and potential 
taxonomic relationships (Van Houdt and Volckaert in draft 2002). All of 
these investigations identified several common, rare, and/or unique 
haplotypes, from mitochondrial deoxyribonucleic acid (mtDNA), among 
burbot populations. In addition, these studies indicate that haplotype 
frequencies and the level of genetic diversity likely also vary among 
the local and regional populations of burbot sampled. Finally, these 
studies indicate that geographic patterning in the genetic profiles of 
burbot are apparent and consistent with known or suspected glacial 
    The results suggest that genetic differences between burbot 
populations in this region may be occurring. The referenced studies 
rely on relatively limited sample sizes and lack information from key 
population segments and/or other major drainages occupied by neararctic 
burbot. Therefore, these investigations are likely to be confounded by 
the effects of small population size, genetic drift, and/or sampling 
bias, and the differentiation patterns noted may similarly reflect the 
potential negative consequences of isolation, range contraction, and/or 
recent significant declines of local burbot populations. As such, to 
what extent the forces of isolation, adaptive change, genetic drift, 
and/or inbreeding may have influenced the genetic profiles of 
neararctic burbot populations, including those that remain within the 
Kootenai River basin, is uncertain. Results of the genetic studies 
further demonstrate the discreteness of the lower Kootenai River 
burbot; however, they do not indicate that genetic differentiation of 
this population segment is significant to the remainder of the taxon. 
No information at this time concludes that the genetic difference that 
is presented in the studies is anything more than what would be 
expected from such a wide-ranging species. More comprehensive 
behavioral, morphological, ecological, and genetic studies of burbot 
are needed to help clarify whether the currently observed differences 
may be significant to the evolutionary legacy of the neararctic taxon.
    Life History/Behavior: As previously discussed, the lower Kootenai 
River burbot does exhibit a different adfluvial life history strategy 
compared to other locally known neararctic burbot populations. For 
example, lower Kootenai River burbot travel greater distances to 
traditional spawning sites (greater than 100 km (62 mi)) than other 
known adfluvial burbot, which typically travel between 1 and 25 km (0.6 
and 15.5 mi). In addition, lower Kootenai River burbot begin their 
migration 2 to 3 months prior to spawning and spawn at least 1 month 
earlier than other burbot populations within the Kootenai River basin. 
However, their spawning time occurs within the wide range of spawning 
periods observed throughout the entire range of burbot. Given the 
circumpolar distribution of the neararctic burbot, it is likely that a 
wide range of behavioral differences are exhibited within the species 
range. Since it is unclear how pliable burbot behavioral patterns may 
be, and how readily, or whether, burbot populations

[[Page 11579]]

may adopt a different life history strategy when faced with changing 
environmental conditions. However, because we currently have very 
little information addressing the life history and behavioral patterns 
of other burbot populations throughout the nearactic region, and 
specifically the relative importance of the adfluvial life history 
strategy, we do not know if these behaviors are unique to the species 
as a whole.
    On the basis of available information, we determined that the life 
history and behavioral characteristics of lower Kootenai River burbot 
do make it discrete from other burbot populations in the local area, 
but, pursuant to our DPS policy, do not make it significant to the 
remainder of the taxon, as we have little information to indicate these 
characteristics are unique to the rest of the taxon.
    Consequently, following a review of the available information, we 
conclude that the population segment of lower Kootenai River burbot is 
not significant to the remainder of the taxon. We made this 
determination because there is no evidence that: (1) This population 
segment persists in an ecological setting that is unique for the taxon; 
(2) the loss would result in a significant gap in the range of the 
taxon; or (3) this population segment differs markedly from other 
populations of the species in its genetic characteristics. Further, we 
do not have sufficient information to indicate that the life history 
and behavioral characteristics of this population segment are unique to 
the taxon. Furthermore, we acknowledge that, while the precise 
biological and ecological importance of a discrete population segment 
is likely to vary considerably from case to case, we were unable to 
identify any additional classes of information that might bear on the 
biological and ecological importance of this discrete population 


    We have assessed the best scientific and commercial information 
available regarding the discreteness and significance of lower Kootenai 
River burbot. We reviewed the petition, information available in our 
files, and other published and unpublished information submitted to us 
during the public comment period following our 90-day petition finding, 
and we consulted with recognized burbot experts and other Federal and 
State resource agencies. On the basis of the best scientific and 
commercial information available, we conclude that the lower Kootenai 
River burbot does not represent a DPS, and is therefore not a listable 
entity. Our review did indicate that the lower Kootenai River burbot is 
discrete from other burbot populations, but was not significant to the 
remainder of the taxon. This finding is primarily based on a lack of 
sufficient evidence to demonstrate that lower Kootenai River burbot 
have marked genetic, ecological, or behavioral differences when 
compared with the remainder of the neararctic subspecies. As such, we 
find that the petitioned action is not warranted.

References Cited

    A complete list of all references cited herein is available on 
request from the Upper Columbia Fish and Wildlife Office (see 


    The primary author of this document is Scott Deeds (see ADDRESSES).


    The authority for this action is the Endangered Species Act (16 
U.S.C. 1531 et seq.).

    Dated: March 3, 2003.
Steve Williams,
Director, Fish and Wildlife Service.
[FR Doc. 03-5737 Filed 3-10-03; 8:45 am]