Mark Wilson and Doug Peterson

U.S. Fish and Wildlife Service

100 N. Park Ave., Suite 320

Helena, MT 59601

RE: Distinct Population Segment (DPS) status for Montana fluvial Arctic grayling

Dear Mr. Wilson and Mr. Peterson:

We understand that the US Fish and Wildlife Service (FWS) may be reviewing its previous finding that the Montana fluvial arctic grayling qualifies as a distinct population segment (DPS). We think that considerable valid scientific evidence that the Montana fluvial grayling in the Big Hole River meet the criteria for listing as a DPS. Although the basis that the FWS would conclude that the Big Hole population is not a valid DPS is difficult to understand, we wish to highlight some of the key findings supporting recognition of Montana fluvial arctic grayling as a DPS. Further, we would like to provide you with the attached letter regarding the DPS status for Montana fluvial Arctic grayling. The letter is authored by several prominent international authorities on Arctic grayling.

According to Fish and Wildlife’s policy for recognition of distinct vertebrate populations, the FWS will consider a population a DPS if it is discrete in relation to the remainder of the species to which it belongs and it is significant to the species to which it belongs. A population is considered discrete if it is markedly separated from other populations because of physical, physiological, ecological, or behavioral factors; or it is delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4 (a) (1) (D). The policy further clarifies that a population need not have absolute reproductive isolation to be recognized as discrete. A population is considered significant based on, but not limited to, the following factors: 1) persistence of the discrete population in an unusual or unique ecological setting; 2) loss of the discrete population would result in a significant gap in range; 3) the population represents the only surviving natural occurrence of an otherwise widespread population that was introduced; or 4) the population differs markedly in its genetic characteristics (Federal Register V. 61, No. 26, February 7, 1996). Montana fluvial Arctic grayling clearly are discrete and meet all of the criteria mentioned by the FWS for considering a population significant.

Arctic grayling occur over a large area; being circumpolar they occur from Siberia, across Alaska and Canada, to Hudson Bay (Kaya 1992). Historically, only two populations of fluvial Arctic grayling occurred in the continental US, one in Michigan, which went extinct around 1936, and one in Montana. The population in Montana formerly occurred in the upper Missouri River and tributaries above Great Falls, but is now restricted to only the upper reaches of the Big Hole River watershed (Kaya 1992). Both the Michigan and Montana populations are believed to be glacial remnants that have been physically and reproductively isolated from more northern populations for 75,000-100,000 years (Lindsay and McPhail 1986 in: Kaya 1992).

Lacustrine populations that historically only occurred in Red Rock Lakes and possibly Elk Lake have greatly expanded in range due to widespread anthropogenic introductions. Lacustrine fish were historically planted into the Big Hole, but according to genetic analysis, apparently did not survive to have any reproductive impact on the native population (Everett 1986).

Therefore based on this evidence, we think Montana fluvial Arctic grayling in the Big Hole River are unequivocally physically and reproductively isolated from Arctic grayling populations in Canada and lacustrine populations in Montana and Wyoming.

Fluvial Arctic grayling in Montana persist as a glacial remnant south of all other populations of fluvial grayling in Canada and Alaska and have developed unique behavior to adapt to life in the Big Hole River that differentiate them from lake populations in Montana and other states. Kaya (1991) and Kaya and Jeanes (1995) found that grayling from the Big Hole River were more likely to hold position in fluvial environments (rheotactic behavior) than grayling derived from lake stock in both laboratory and stream environments. Based on intermediate rheotactic behavior in individuals that are hybrid between fluvial and lacustrine fish, this behavior is likely genetically derived (Kaya 1991 and 1992).

Fluvial grayling have also been found to migrate within the Big Hole River, overwintering downriver in some cases as far as Divide Dam, where there are large pools that do not freeze, and spending the spring in summer in upstream environments, more suitable for spawning and foraging (Shepard and Oswald 1989, Kaya 1992). Migration distances have been as great as 80 km.

Because of both a lack of rheotactic behavior, and the migratory behavior to winter in different habitat types than spawning, provide evidence Big Hole grayling have unique adaptations to fluvial environments and potentially to the Big Hole itself; and are thus, not easily replaced if allowed to go extinct.

Differences in behavioral adaptation between Big Hole populations and fluvial populations in Canada and Alaska are less well documented. However, given the length of isolation of the Big Hole population and differences in latitude between the Big Hole and more northerly populations, it is likely that Montana fluvial Arctic grayling are specifically adapted to the unique environments of the Big Hole River.

Clearly, extinction of the Montana fluvial Arctic grayling would result in the loss of fluvial grayling from the continental US and the extinction of the species as a glacial remnant in more southerly latitudes than the majority of its current range. The FWS has recognized the significance of continental US populations of otherwise widespread species in a number of cases, most notably listing of the grizzly bear and gray wolf.

Lacustrine forms of arctic grayling have been widely introduced in lakes in Montana, Wyoming, and other states. However, only the Big Hole population represents the native fluvial form, as evidenced limited genetic and behavioral studies (Everett 1985, Kaya 1991, Kaya and Jeannes 1995). The only confirmed self-sustaining population of Montana grayling, which lives continuously and permanently in a flowing-water environment is that of the upper Big Hole River and lower parts of its tributaries (Kaya 1992).

Some genetic evidence exists to demonstrate that Montana fluvial Arctic grayling found in the Big Hole River differ markedly from both grayling in Canada and Alaska and lacustrine populations found in Montana and other states. There are significant differences in allele frequencies among populations. Regardless of habitat type, hatchery populations are most closely related to one another, whereas the Big Hole River drainage populations, with native fish, are distinct. There is no evidence of introgression with transplanted arctic stocks. High frequency variants observed in the non-native populations would make mixed stocks detectable (Everett 1986). More specifically, Everett (1986) noted that the Big Hole River population has a creatine kinase variant seen in no other populations. These results were further confirmed by later work by Leary (1989). Further, Kaya (1991 and 1992) believed based on behavior of hybrids that rheotactic behavior of grayling from the Big Hole is likely genetically determined and not similarly present in non-fluvial fish. Kaya (1992) concluded that Arctic grayling in Montana are genetically diverged from more northern populations in Alaska and Canada, and the remnant fluvial population of the Big Hole River is a reproductively isolated stock of Montana grayling that is genetically identifiable and behaviorally adapted to riverine existence.

The attached letter from grayling biologists reflects the ongoing concern of the Big Hole River Foundation for the pending ESA determination regarding Big Hole River grayling. The letter is, in some sense, is a follow up to a grayling symposium hosted by the foundation in August of 2005.

As the last remaining fluvial population of a fish once common throughout the upper Missouri River watershed (above Great Falls, Montana), we think there exists substantial scientifically valid evidence to warrant endangered species status of the Big Hole River grayling (i.e. Montana fluvial Arctic grayling). In the 20 years that this species has been recognized as being in serious decline in the lower-48 states, Montana has tried to conserve and restore this fish. Unfortunately, even under Montana’s management, the population of Big Hole River grayling has steadily declined. Today, Montana FWP estimates that only about 1,000 fish remain—perilously close to the theoretical threshold for viability.

Although the genetics data is arguably inconclusive regarding the difference between fluvial and lacustrine populations of Arctic grayling in Montana, we believe the DPS significance question is not.

Thank you for your valuable time and considerartion of our position and the information presented in the attached letter. Although we realize that this is largely an internal determination to be made by the FWS, we are also aware that Montana Fish, Wildlife and Parks has had an opportunity to weigh in on this issue, and that these communications argued for combining the fluvial and lacustrine populations into a single DPS.

Respectfully,

Michael A. Bias, Ph.D.

Executive Director

cc: Julie Lyke, Assistant Regional Director

U.S. Fish and Wildlife Service

Denver Federal Center

Denver, CO 80225

References:

Kaya, C.M. 1991. Rheotactic differentiation between fluvial and lacustrine populations of arctic grayling (Thymallus arcticus), and implications for the only remaining indigenous population of fluvial “Montana grayling.” Canadian Journal of Fisheries and Aquatic Science, 48: 53-59.

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

Kaya, C.M., and E.D. Jeanes. 1995. Retention of adaptive rheotactic behavior by F1 fluvial arctic grayling. Transactions of the American Fisheries Society 124: 453-457.

Leary, R. 1989. Letter to C.M. Kaya, October 27, 1989. University of Montana, Division of Biological Sciences, Missoula, MT.

Magee, J., and P. Lamothe. 2003. Big Hole River fluvial arctic grayling monitoring report 2002. Montana Department of Fish, Wildlife and Parks.

Shepard, B.B., and R.A. Oswald. 1989. Timing, location and population characteristics of spawning Montana arctic grayling (Thymallus arcticus montanus) in the Big Hole River drainage. Report to Montana Fish, Wildlife and Parks.

September 15, 2006

Mark Wilson and Doug Peterson

U.S. Fish and Wildlife Service

100 N. Park Ave., Suite 320

Helena, MT 59601

CC: Julie Lyke, Assistant Regional Director

U.S. Fish and Wildlife Service

Denver Federal Center

Denver, CO 80225

Dear Mark and Doug,

As fisheries biologists with expertise in the biology and ecology of Arctic grayling, we are writing to support continued recognition of the Montana grayling as a distinct population segment (DPS), either including only fluvial populations (referred to as “Montana fluvial Arctic grayling”) or a combination of fluvial populations and native adfluvial and lacustrine populations (referred to as “Montana grayling”). The U.S. Fish and Wildlife Service (FWS) first recognized Montana fluvial Arctic grayling as a DPS in 1994, concluding:

“Because fluvial Arctic grayling are adapted to life-long residence in stream environments, they are believed to be behaviorally distinct from adfluvial grayling. Evidence of this apparently innate behavioral adaptation is demonstrated in young fluvial grayling tending to hold their position in a stream current rather than moving downstream with the current as adfluvial grayling do (Kaya 1991)” (FWS 1994).

Since 1994, FWS has twice reviewed the status of Montana fluvial Arctic grayling and concluded in both cases that it warranted continued recognition as a DPS (Campton and Ardren 2004, FWS 2004). In 2005, Dr. Robb Leary, of University of Montana’s Conservation Genetics Laboratory, reviewed the genetics information supporting recognition of the DPS and concluded: “I do not think the available genetic data support recognizing the fluvial and lacustrine life history forms of Arctic grayling in the upper Missouri River drainage as distinct population segments” (Leary 2005). Based on this conclusion, it appears FWS is considering reversing its previous recognition of Montana Fluvial Arctic Grayling as a DPS (Campton 2006).

Although Leary (2005) is correct that available genetic data on differences between fluvial and adfluvial populations is inconclusive, we strongly believe that the best available scientific evidence supports recognition of Montana fluvial Arctic grayling as a DPS based on factors not considered by Leary (2005) and dictated by FWS’s policy on recognition of distinct population segments (Federal Register V. 61, No. 26, February 7, 1996). Alternatively, we support designation of fluvial and native adfluvial populations as a single DPS.

According to FWS’s DPS policy, a population will be considered a DPS if it is “discrete” in “relation to the remainder of the species to which it belongs” and it is “significant” to the species to which it belongs. A population is considered discrete if it is “markedly separated from other populations” because of “physical, physiological, ecological, or behavioral factors;” or it is “delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4 (a) (1) (D).” The policy further clarifies that a population need not have “absolute reproductive isolation” to be recognized as discrete. A population is considered significant based on, but not limited to, the following factors: 1) “persistence of the discrete population in an unusual or unique ecological setting;” 2) “loss of the discrete population would result in a significant gap in range;” 3) the population “represents the only surviving natural occurrence of an otherwise widespread population that was introduced;” or 4) the population “differs markedly in its genetic characteristics.”

In relation to extensive populations of fluvial Artic grayling in Canada and Alaska, Montana grayling are widely recognized as being significant based primarily on marked genetic differences, but also based on occurrence in a unique ecological setting and that loss of the population would result in a significant gap in the range of the species (Campton and Ardren 2004, FWS 2004, Leary 2005, Campton 2006). Leary (2005), for example, concludes:

“Considering the allozyme and mtDNA data, it is clear that Arctic grayling in the upper Missouri River drainage are highly divergent from those in other portions of the species’ range. This is not unexpected given their disjunct distribution and complete reproductive isolation for tens of thousands of years (Redenbach and Taylor 1999). Because of their disjunct distribution and high amounts of detectable genetic divergence, upper Missouri River Arctic grayling certainly would warrant being considered a distinct population segment under the U.S. Endangered Species Act.”

And Redenbach and Taylor (1999) also conclude:

“Our data also show that a disjunct southern set of populations in Montana is significantly different from the northern Grayling, in terms of restriction haplotype frequency and distinguishing sequence characteristics. Sequence results yielded an estimated divergence time of 370 000 years between the northern and Montana grayling haplotypes.”

Accordingly, both Leary (2005) and Campton (2006) recognize that Montana Grayling are distinct from grayling in Alaska and Canada. Both authors, however, question the distinctiveness of fluvial from adfluvial populations of grayling in Montana. Although FWS has recognized fluvial populations as a DPS since 1994, should the agency find that fluvial and adfluvial populations are not distinct, we hereby request that the agency consider protecting Montana Grayling as a whole, including both fluvial and native adfluvial populations. Given that fluvial populations are reduced to less than 5% of their historic range (Kaya 1992), that the native population in Elk Lake is believed extinct, and that grayling only occur in small numbers in Red Rock Lakes, listing native populations of the grayling in Montana regardless of whether they are fluvial or adfluvial is clearly warranted. Indeed, FWS (2004) concluded:

“The current DPS justification focuses exclusively on the fluvial Arctic grayling life-history type that was thought to predominate in the upper Missouri River basin prior to Euro-American settlement. By extension, the data are also consistent with the hypothesis that native adfluvial Arctic grayling constitute a separate DPS within the upper Missouri River (e.g., Campton and Ardren 2004). However, if all indigenous Arctic grayling of the upper Missouri River (both adfluvial and fluvial life histories) were considered as a single unit, we believe this unit would also qualify as a DPS. Thus a DPS called “ the upper Missouri River DPS of Arctic grayling ” which incorporates all three remaining indigenous Arctic grayling populations in Montana (i.e., fluvial Big Hole River, adfluvial Red Rocks/Elk lakes, adfluvial/fluvial Madison River/Ennis Reservoir), would also be justified based on a common post-glacial isolation and resulting genetic distinctiveness relative to northern stocks of Arctic grayling (Scott and Crossman 1973; Lynch and Vyse 1979; Everett and Allendorf 1985; Redenbach and Taylor 1999; Campton and Ardren 2004). This more inclusive DPS would remain significant because it supports the only remnants of indigenous Arctic grayling in the contiguous U.S., regardless of life-history type. A proposed rule will need to define the scope of a DPS for the Arctic grayling of the upper Missouri River basin.”

Accordingly, we provide the following information in support of continued recognition of Montana fluvial Arctic grayling, or alternatively Montana grayling, as a DPS.

1. Montana Fluvial Arctic Grayling and Montana Grayling persist in an unusual or unique ecological setting.

Montana grayling occur in a unique ecological setting that differs substantially from other Arctic grayling populations. FWS (2004) concluded:

“The upper Missouri River is an ecological setting unusual or unique for Arctic grayling. Arctic grayling evolved in Arctic waters. However, the fluvial Arctic grayling of the upper Missouri represent the only natural example of the taxon inhabiting an Atlantic Ocean drainage (via the Missouri and Mississippi rivers and Gulf of Mexico). All other wild populations of Arctic grayling inhabit drainages generally characterized as Arctic (e.g., draining into Hudson’s Bay, the Arctic Ocean, or the North Pacific Ocean). Arctic grayling of the upper Missouri River basin are the only extant fluvial grayling population in the contiguous United States, and represent the southernmost extent of the species (Scott and Crossman 1973; Kaya 1990; Campton and Ardren 2004). The disjunct location of the upper Missouri River Arctic grayling is the result of Pleistocene glacial activity (Scott and Crossman 1973). These grayling appear to be the only example of the taxon which naturally occur in the steppe-coniferous forest-tundra province of the dry ecoregion domain, whereas most other North American grayling populations are found in a polar or humid temperate zone (see Bailey 1998 for ecoregion boundaries). Thus, they moreover inhabit a unique ecological setting characterized by a specific suite of geoclimatic and vegetation characteristics.”

This conclusion alone warrants recognition of either Montana fluvial Arctic grayling or Montana grayling as DPS.

Within Montana grayling, Montana fluvial Arctic grayling contain the only river-dwelling populations of the species and thus occur in a unique ecological setting. This conclusion is supported by the fact that Montana fluvial Arctic grayling have developed unique behavior to adapt to life in the Big Hole River that differentiate them from lake populations in Montana and other states. Kaya (1991) and Kaya and Jeanes (1995) found that grayling from the Big Hole River were more likely to hold position in fluvial environments (rheotactic behavior) than grayling derived from lake stock in both laboratory and stream environments. Based on intermediate rheotactic behavior in individuals that are hybrid between fluvial and adfluvial fish, this behavior is believed to be genetically derived (Kaya 1991 and 1992).

Fluvial grayling have also been found to migrate within the Big Hole River, overwintering downriver in some cases as far as the former Divide Dam, where there are large pools that don’t freeze, and spending the spring and summer in upstream environments, more suitable for spawning and foraging (Shepard and Oswald 1989, Kaya 1992). Migrations have been recorded of up to 80 km. Similar behavior has not been observed in adfluvial populations.

Likely because of both a lack of rheotactic behavior and the instinct to make seasonal migrations to find better habitat, numerous introductions of adfluvial fish into rivers of both Montana and Michigan have failed (Kaya 1992), and more recently hatchery raised offspring of Big Hole fish planted into other rivers within the historic range of the species have failed to produce self-sustaining populations (Magee and Lamothe 2003). Such failures indicate that Big Hole grayling have unique adaptations to fluvial environments and potentially to the Big Hole itself and are thus not easily replaced if allowed to go extinct. Kaya (1991) concluded:

“Big Hole River grayling appear to be adapted to permanent stream residence. Such adaptation reinforces the importance of conserving the last indigenous fluvial population of the geographically disjunct, genetically identifiable ‘Montana grayling’.”

Thus, both Montana grayling and Montana fluvial Arctic grayling qualify as DPS because they occur in unique ecological settings.

2. Loss of the discrete population would result in a significant gap in range.

Montana fluvial Arctic grayling were formerly one of two disjunct populations in the contiguous United States. The other formerly occurred in Michigan and became extinct in the 1930’s, leaving Montana grayling as the sole population left in the contiguous U.S. Accordingly, FWS (2004) concluded that loss of the fluvial population would result in a significant gap in the range of the species:

“Loss of this population would result in the extirpation of the fluvial Arctic grayling from the contiguous United States, and represent the loss of a population which was estimated to formerly inhabit 1,250 miles of stream and river habitat (Kaya 1990). The loss of this population would thus increase the gap in the species’ range.”

This conclusion applies equally to either fluvial populations solely, particularly since this comprises the majority of the species’ native range, or the combination of fluvial and adfluvial populations.

3. Montana Fluvial Arctic Grayling represent the only surviving natural occurrence of a once widespread population.

Adfluvial populations of Montana grayling have been established in numerous lakes outside the original range of the species, which formerly only included Red Rock Lakes, Elk Lake, and a few smaller lakes in the Big Hole drainage (Kaya 1992, FWS 2004). The native adfluvial life history form is extinct in Elk Lake and apparently doing poorly in Red Rocks Lakes but has been widely introduced in numerous lakes. The native adfluvial form has been widely introduced into other lakes. The native fluvial life history form is nearly extinct in the fluvial portion of its range. New introductions or reintroductions of the fluvial form have not been successful.

4. Montana Fluvial Arctic Grayling differ markedly in their genetic characteristics

Leary (2005) questioned whether fluvial Arctic grayling are distinct from adfluvial populations also found in Montana based primarily on genetics. Discussing allozyme analyses performed by Everett (1986) and Leary (1990), Leary (2005) concluded:

“The bivariate plot of the GAPDH-3*null and SOD*145 allele frequencies indicates that the two genetically most similar samples appear to be the Big Hole River and Madison River. The lake samples, however, do not appear to constitute a separate group. Rather, the Miner Lake population is very divergent from all the others and this divergence would be even greater if we considered the unique PGM-1*49 allele that was detected in the sample. Apparently, there is also significant divergence between the Red Rock Lakes and Elk Lake samples. The Elk Lake sample appears only slightly more similar to the Red Rock Lakes sample than the Big Hole River and Madison River samples. Thus, the lacustrine samples do not appear to form a genetically distinct group. Taken at face value, therefore, these data do not support the premise that the fluvial and lacustrine life histories fall out into two distinct lineages. In contrast, they suggest relatively substantial divergence among populations regardless of life history.”

Several factors qualify Leary’s conclusions and suggest that there may be marked genetic differences between fluvial and lacustrine populations. First, Leary (2005) acknowledged that the dataset was very limited, stating:

“Although allozyme data from 39 loci are available from the presumed native Big Hole River, Madison River, Miner Lake, Red Rock Lakes, and the now believed extinct Elk Lake populations, only two of the loci analyzed (GAPDH-3* and SOD*) were generally variable (polymorphic) among them (Everett 1986; Leary 1990). Thus, in terms of comparing the genetic characteristics of these populations using allozyme data we are really using information from only two loci. When performing population comparisons, therefore, we must keep in mind that we are dealing with a very weak data set. That is, since we are basically using information from only two loci there is apt to be a lot of noise in the data and apparent similarities or differences may be more fortuitous than real. In this situation, results must be interpreted cautiously.”

It is unfortunate that despite the passing of sixteen years, when the grayling has been a candidate for listing in one form or another for the entire time, FWS has not funded or carried out additional genetic studies to clarify the relationship of fluvial and lacustrine grayling populations and that there is not a more extensive dataset to evaluate a question that will determine if the grayling will receive additional protection and conservation. Given this critical lack of data (and lack of statistical certainty for existing data), FWS should give additional weight to the other factors for determining whether a population qualifies for recognition as a DPS as discussed above.

Second, the existing genetic data provide evidence that Montana fluvial Arctic grayling found in the Big Hole are genetically distinct. Everett (1986), for example, concluded:

“The genetic identities among all populations studied are high. Nevertheless, there are significant differences in allele frequencies among populations. Regardless of habitat type, the hatchery populations are most closely related to one another whereas the Big Hole River Drainage populations, with native fish are distinct.”

And further noted that “there are significant genetic differences between populations.”

Moreover, Dr. Leary concluded in 1989 that:

“The other noteworthy feature is the presence of two clusters at an average genetic distance of 0.0065. One cluster contains all populations believed to be representative of native Big Hole River drainage grayling: Big Hole River, Bobcat Lake, Miner Lake, Mussigbrod Lake, and Steel Creek. The other cluster that contains Deer Lake represents those populations that directly or indirectly founded from Madison River and Red Rocks Lake grayling” (Leary 1989).

These conclusions led Campton and Ardren (2004), in their review of whether Montana Fluvial Arctic Grayling qualify as a DPS, to conclude:

“The best available genetic information for populations of Arctic grayling in the upper Missouri River support the hypothesis of two genetically diverged groups (Table 1; Figs. 1, 2, and 3; data from Everett 1986 and Leary 1990). One genetic group consists of populations in Red Rock Lakes, Elk Lake, and O’Dell Creek (tributary to lower Red Rock Lake) and includes several naturalized, lacustrine populations derived from historical introductions (e.g. Agnes, Grebe, Rogers, Deer and Elizabeth lakes). A second genetic group consists of populations in the Big Hole River and adjoining waters in the Big Hole River drainage (Bobcat, Miner, Mussigbrod lakes and Steel Creek) but also includes fish (n=21) from the Madison River. These two groups are characterized by divergent allele frequencies at two allozyme loci: Gapdh-3* and sSOD-1*.”

Based in part on this genetic information, Campton and Ardren (2004) ultimately concluded that Montana Fluvial Arctic Grayling do qualify as a distinct population segment. Campton (2006) later reversed this conclusion, stating: “the two genetic groups described above satisfy the discreteness criterion of the DPS policy, but the existing data are insufficient at this time to demonstrate that they also satisfy the significance criterion of that policy.” In doing so, however, Campton (2006) still concluded:

“The available genetic data further suggest the existence of two genetic groups of Arctic grayling in Montana: (1) a group of native and naturalized populations represented by lacustrine populations indigenous to Red Rock and Elk lakes in the upper Red Rock River and (2) a Big Hole River group that includes a fluvial population in the Big Hole River, an adfluvial population in Ennis Reservoir and the Madison River, and at least three lacustrine populations in the Big Hole River drainage.”

Campton (2006) thus does not base his conclusion that there may not be sufficient information to continue recognizing Montana Fluvial Arctic Grayling as a DPS on a lack of genetic distinctiveness, but rather on the fact that “the presence of lacustrine populations within the ‘Big Hole River’ group might argue against the ‘ecological significance’ of the two groups, as prescribed under the significance criterion of the DPS policy.” Contrary, to this conclusion Campton (2006) also notes that:

“The best available genetic data are consistent with the hypothesis that Arctic grayling from the Ennis Reservoir population, a potential remnant population of the Big Hole River group, have not successfully contributed genetically to introduced, naturalized populations despite known broodstock and stocking records. Similarly, genetic data (reviewed here) and field observations (Doug Peterson, FWS, pers. comm.) both indicate that hatchery-produced Arctic grayling derived ancestrally from the Red Rock Lakes group do not appear to have survived or reproduced in the Big Hole River. These data suggest, along with some of the behavioral data presented by Kaya (1989, 1991) and Kaya and Jeanes (1995), that the two groups are not “ecologically exchangeable”.

The fact that the Big Hole distinct lineage includes some lacustrine and adfluvial populations does not negate observed genetic differences that qualify the population for recognition as a DPS, as the DPS policy does not include a requirement that observed genetic differences correspond with observed behavioral differences.

Likewise, Leary (2005) does not base his conclusion that the adfluvial and fluvial populations do not qualify as distinct lineages on a lack of distinctiveness of the Big Hole and Madison River populations, but rather on the variability of the lake populations, stating:

“Thus, the lacustrine samples do not appear to form a genetically distinct group. Taken at face value, therefore, these data do not support the premise that the fluvial and lacustrine life histories fall out into two distinct lineages.”

Because the lacustrine populations do not form a distinct genetic group (given the limited data set), however, does not mean that the Big Hole River populations do not qualify as a distinct population segment, provided as is the case here, that the Big Hole River populations group together and are distinct from other populations.

In sum, existing genetic data indicates that grayling populations found in the Big Hole River, Madison River, and a few lakes within the Big Hole drainage are distinct from other lake populations. In combination, with data indicating that Montana fluvial Arctic grayling occur in a unique ecological setting and that their loss would result in a significant gap in the range, there appears to ample evidence to support recognition of Montana fluvial Arctic grayling as a DPS. Furthermore, conclusive genetic data shows Montana grayling are distinct from Arctic grayling in Canada and Alaska, which combined with the fact that loss of Montana grayling from the contiguous United States would create a gap in range, that Montana grayling occur in a unique ecological setting, and that Montana grayling represent the last natural occurrence of an otherwise widespread species that was introduced, there is also ample evidence to support recognition of Montana grayling as a DPS. It is our combined scientific opinion that were FWS to fail to recognize either of these DPSs of the grayling it would undermine conservation of the last remaining populations of the species in the contiguous U.S., would be a clear failure to rely on the best available scientific information, and would be counter to the clear mandates of the Endangered Species Act.

Sincerely,

B.G. Blackman Registered Professional Biologist

Senior Fish Biologist

Peace/Williston Fish & Wildlife Compensation Program

1011 Fourth Avenue, 3rd. Floor

Prince George, BC V2L 3H9

Phone: (250) 565 - 6413 Fax: (250) 565 - 6629

Email: Brian.Blackman@.gov.bc.ca

Website: http://www.bchydro.com/pwcp

[Please note that in signing this letter Mr. Blackman does not represent BC Hydro in any capacity.]

Robert A. Clark, Fisheries Scientist I

Alaska Department of Fish and Game

Sport Fish Division—Research and Technical Services

333 Raspberry Rd

Achorage AK 99518-1599

Wayne Hadley, PhD

Fisheries Biologist, Retired

1016 Eastside Rd

Deer Lodge MT 59722

Jim O'Neil, Professional Biologist

Senior Fisheries Biologist, Principal

Golder Associates Ltd.

#300, 10525 - 170 Street

Edmonton, AB T5P 4W2

ph: 780-483-3499

fx: 780-483-1574

jim_o'neil@golder.com

Website: www.golder.com

Literature cited:

Campton, D.E. 2006. Should Arctic grayling in the Big Hole River, Montana be considered a Distinct Population Segment (DPS) under the U.S. Endangered Species Act? An Evaluation of Existing Genetic Information. U.S. Fish and Wildlife Service

Abernathy Fish Technology Center, Longview, WA. January 12, 2006.

Campton, D.E., and W.R. Ardren. 2004. Should fluvial Arctic grayling in the Big Hole River, Montana be considered a Distinct Population Segment (DPS) under the U.S. Endangered Species Act? An Evaluation of Existing Genetic Information. U.S. Fish and Wildlife Service Abernathy Fish Technology Center, Longview, WA. July 26, 2004.

Everett, R.J. 1986. The population genetics of Arctic grayling (Thymallus arcticus) of Montana. Master’s thesis, University of Montana, Missoula.

FWS. 1994. Endangered and threatened wildlife and plants; finding on a petition to list the fluvial population of the Arctic grayling as endangered. Federal Register 59 (141):

37738-37741 (July 25, 1994).

FWS. 2004. U.S. Fish and Wildlife Service Species Assessment and Listing Priority Assignment Form for fluvial Arctic grayling (distinct population segment of the Upper Missouri River), commonly called Montana Arctic grayling. November 30, 2004.

Kaya, C.M. 1991. Rheotactic differentiation between fluvial and lacustrine populations of arctic grayling (Thymallus arcticus), and implications for the only remaining indigenous population of fluvial “Montana grayling.” Canadian Journal of Fisheries and Aquatic Science, 48: 53-59.

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

Kaya, C.M., and E.D. Jeanes. 1995. Retention of adaptive rheotactic behavior by F1 fluvial arctic grayling. Transactions of the American Fisheries Society 124: 453-457.

Leary, R. 1989. Letter to C.M. Kaya, October 27, 1989. University of Montana, Division of Biological Sciences, Missoula, MT.

Leary, R. 2005. Letter to Bob Snyder, Montana Department of Fish, Wildlife, and Parks

From Robb Leary, Montana Conservation Genetics Laboratory, University of Montana. December 20, 2005.

Magee, J., and P. Lamothe. 2003. Big Hole River fluvial arctic grayling monitoring report 2002. Montana Department of Fish, Wildlife and Parks.

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