[Federal Register: March 11, 2003 (Volume 68, Number 47)]
[Notices]
[Page 11574-11579]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr11mr03-80]
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DEPARTMENT OF THE INTERIOR
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.
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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.
SUPPLEMENTARY INFORMATION:
Background
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
Register.
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
seasons.
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
maculosa.
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
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
discreteness.
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
present).
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.
Significance
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
maculosa):
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
species.
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
refugia.
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
segment.
Finding
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
ADDRESSES).
Author
The primary author of this document is Scott Deeds (see ADDRESSES).
Authority
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]
BILLING CODE 4310-55-P