Endangered and Threatened Wildlife and Plants: 12-Month Finding on a Petition to List the Coaster Brook Trout as Endangered
Federal Register: May 19, 2009 (Volume 74, Number 95)
Proposed Rules
Page 23376-23388
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
DOCID:fr19my09-22
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service 50 CFR Part 17
FWS-R3-ES-2008-0030; 92210-1111-0000-FY09-B3
Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List the Coaster Brook Trout as Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 12-month petition finding.
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 12-month finding on a petition to list the coaster brook trout
(Salvelinus fontinalis) as endangered under the Endangered Species Act of 1973, as amended (Act). The petition also asked that critical habitat be designated for the species. After review of all available scientific and commercial information, we find that the coaster brook trout is not a listable entity under the Act, and therefore, listing is not warranted. We ask the public to continue to submit to us any new information that becomes available concerning the taxonomy, biology, ecology, and status of coaster brook trout and to support cooperative conservation of coaster brook trout within its historical range in the
Great Lakes.
DATES: The finding announced in this document was made on May 19, 2009.
ADDRESSES: This finding is available on the Internet at http:// www.regulations.gov at Docket Number [FWS-R3-ES-2008-0030]. Supporting documentation for this finding is available for inspection, by appointment, during normal business hours at the U.S. Fish and Wildlife
Service, Region 3 Fish and Wildlife Service Regional Office, 1 Federal
Drive, Bishop Henry Whipple Federal Building, Fort Snelling, MN 55111.
Please submit any new information, materials, comments, or questions concerning this finding to the above address, Attention: Coaster brook trout.
FOR FURTHER INFORMATION CONTACT: Jessica Hogrefe, Region 3 Fish and
Wildlife Service Regional Office (see ADDRESSES) (telephone 612-713- 5346; facsimile 612-713-5292). Persons who use a telecommunications device for the deaf (TDD) may call the Federal Information Relay
Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(B) of the Act (16 U.S.C. 1531 et seq.) requires that, for any petition to revise the Lists of Endangered and Threatened
Wildlife and Plants that contains substantial scientific and commercial information that listing may be warranted, we make a finding within 12 months of the date of our receipt of the petition on whether the petitioned action is: (a) Not warranted, (b) warranted, or (c) warranted, but the immediate proposal of a regulation implementing the petitioned action is precluded by other pending proposals to determine whether species are threatened or endangered, and expeditious progress is being made to add or remove qualified species from the List of
Endangered and Threatened Species. Section 4(b)(3)(C) of the Act requires that we treat a petition for which the requested action is found to be warranted but precluded as though resubmitted on the date of such finding, that is, requiring that we make a subsequent finding within 12 months. Such 12-month findings must be published in the
Federal Register. This notice constitutes our 12-month finding for the petition to list the U.S. population of coaster brook trout.
Previous Federal Action
The Sierra Club Mackinac Chapter, Huron Mountain Club, and Marvin
J. Roberson filed a petition, dated February 22, 2006, with the
Secretary of the Interior to list as endangered the ``naturally spawning anadromous (lake-run) coaster brook trout throughout its known historic range in the conterminous United States'' and to designate critical habitat under the Act. The petition clearly identified itself as such and included the requisite identification information for the petitioners, as required in 50 CFR 424.14(a). On behalf of the petitioners, Peter Kryn Dykema, Secretary of the Huron Mountain Club, submitted supplemental information, dated May 23, 2006, in support of the original petition. This supplemental information provided further information on the species' status and biology, particularly for brook trout in the Salmon Trout River.
On September 13, 2007, we received a 60-day notice of intent to sue over the Service's failure to determine, within 1 year of receiving the petition, whether the coaster brook trout warrants listing. Under section 4 of the Act, the Service is to make a finding, to the maximum extent practicable within 90 days of receiving a petition, that it does or does not present substantial scientific or commercial information indicating that the petitioned action may be warranted. Further, the
Act requires that, within 12 months of receiving a petition found to present substantial information, the Service must determine whether the petitioned action is warranted. A complaint was filed in U.S. District
Court in the District of Columbia on December 17, 2007, for failure to make a timely finding (Sierra Club, et al. v. Kempthorne, No. 1:07-cv- 02261 (D.D.C. December 17, 2007)). The Service reached a negotiated settlement with the plaintiffs to submit the 90-day finding to the
Federal Register by March 15, 2008. We published a ``substantial'' 90- day finding March 20, 2008. The negotiated settlement further required the Service to publish the 12-month finding in the Federal Register by
December 15, 2008. The deadline for the 12-month finding was extended to April 15, 2009, by mutual consent. On April 15, 2009, we filed an unopposed motion to extend the deadline for the coaster brook trout 12- month finding to May 12, 2009.
Species Information
Species Description
Brook trout (Salvelinus fontinalis), also called brook char or speckled trout, is one of three species in the genus Salvelinus (chars) native to north and eastern North America; the others being lake trout
(S. namaycush) and Arctic char (S. alpinus). The chars are a sub-group of fishes in the salmon and trout subfamily (Salmoninae) that is distinct from the ``true'' trout and salmon sub-groups.
The brook trout throughout its range in eastern North America exhibits considerable variation in growth rate, color, and other features, but generally can be distinguished from other char and trout species by its olive-green to dark brown back with a light yellow-brown vermiculate pattern, sides with large yellow-brown spots and blue halos surrounding small, sporadic red and orange spots. Pectoral, pelvic, anal, and lower caudal fin have leading edges of white bordered by black with the
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remainder predominantly reddish to orange. Sea-run brook trout become silver with purple iridescence and show red spots on the sides (Scott and Crossman 1973, p. 208).
Distribution
The historical range of native brook trout extends along Hudson Bay in Canada across the Provinces of Manitoba, Ontario and Quebec, to
Newfoundland and Labrador and south to Nova Scotia and New Brunswick in
Canada; and from eastern Iowa through northern Illinois, northern Ohio, and the Great Lakes drainage (Minnesota, Michigan, Wisconsin), through the New England States (New York, New Hampshire, Vermont, Maine,
Massachusetts, Pennsylvania, New Jersey), large New England rivers
(such as the Hudson River and Connecticut River), and through the
Appalachian Mountains in Maryland, Virginia, West Virginia, North
Carolina, South Carolina, Tennessee, south to Georgia (MacCrimmon and
Campbell 1969, pp. 1700-1702; MacCrimmon et al. 1971, p. 452; Scott and
Crossman 1973, pp. 209-210; Power 1980, p. 142). Naturalized populations of brook trout were established as early as the late 1800s beyond the historical native range by introductions to waters in western North America, South America, Eurasia, Africa, and New Zealand
(MacCrimmon and Campbell 1969, p. 1699, pp. 1703-1717). The current range of native brook trout still extends through Canada and down to
Georgia in the U.S., but in many locations, populations have been completely extirpated or have contracted within this range towards upper stream reaches, higher altitudes, or headwaters (EBJV 2006, p. 2).
Distribution of Brook Trout in the Great Lakes
According to Bailey and Smith (1981, p. 1549) and MacCrimmon and
Campbell (1969, p. 1701), brook trout are native to the lakes and tributaries of Lakes Superior, Huron, Michigan, and the tributaries of
Lakes Erie and Ontario. Brook trout are not believed to have been present in Minnesota streams above barrier falls to Lake Superior
(Smith and Moyle 1944, p. 119) or throughout most of the lower peninsula of Michigan (MIDNR 2008a, pp. 1-2; MacCrimmon and Campbell 1969, p. 1704).
Habitat Requirements
Brook trout require clear, cold, well-oxygenated water to thrive.
They are generally found in water ranging between 41-68[deg] Fahrenheit
(5-20[deg] Celsius), with their likely preferred temperature falling near the middle of this range (Power 1980, p. 172). Thermal requirements within this range vary by life cycle phase and season
(Scott and Crossman 1973, p. 211; Blanchfield and Ridgway 1997, p. 750;
Baril and Magnan 2002, pp. 177-178).
The brook trout spawns in late summer or autumn, the date varying with latitude and temperature. Spawning takes place most often over gravel beds but may be successfully accomplished over a variety of substrates if there is spring upwelling or a moderate current (Scott and Crossman 1973, p. 210). Power (1980, p. 151) describes rangewide brook trout spawning, which occurs in the fall, when day length and temperature are decreasing. In northerly regions and at high elevations, brook trout may spawn as early as late August and spawning may be delayed until December in southern areas. As is typical for salmonids, females prepare redds (hollows scooped out for spawning) in suitable gravel substrate. The female then deposits her eggs in the redd where they are fertilized by a male. After spawning there is no further parental involvement with the young. The redd protects the eggs and allows an adequate exchange of dissolved gases and other materials during development.
Brook trout are carnivorous, feeding opportunistically upon a variety of prey, such as worms, leeches, crustaceans, aquatic insects, terrestrial insects, spiders, mollusks, and fish (Scott and Crossman 1973, p. 212). Anadromous (migrating from salt water to spawn in fresh water) forms vary their feeding behavior and prey items based on their age and the environment, marine or riverine, they are occupying (Newman and Dubois 1997, p. 9). Brook trout also show diverse foraging behaviors; some individuals may be sedentary, eating crustaceans from the lower portion of the water column, whereas others in the same system may be more active and eat insects from the upper portion of the water column (McLaughlin et al. 1999, p. 386). This resource polymorphism may play a supplementary role in the extensive adaptive radiation (evolution of ecological variability within a rapidly multiplying lineage; Smith and Sk[uacute]lason 1996) observed in this species.
Genetics of Brook Trout
A large amount of genetic variation for brook trout is distributed among populations (large Fst values). This pattern is heavily influenced by the diverse ecological and life-history characteristics of brook trout populations (population connectivity or isolation, philopatric tendency). This pattern of highly differentiated populations of brook trout is found at small and large geographic scales. Population genetic structuring is common in brook trout throughout its range (Angers et al. 1999, pp. 1049- 1050). Like many salmonids, brook trout tend to have a hierarchical population structure resulting from the hierarchical design of the networks of streams and lake or coastal areas in which they live, and a complicated life cycle that leads to strong local adaptations.
Taxonomic resolution can be even more complicated at the lake level when lakes include sympatric (occupying the same or overlapping geographic area without interbreeding) but genetically divergent brook trout populations such as in Lake Mistassini in Canada (Fraser and Bernatchez 2008, p. 1197). This degree of genetic divergence that forms among populations is reflective of the reproductive connections (isolation) among the populations across the range of the taxon.
Six distinct genetic mitochondrial (mtDNA) clades have been identified throughout the range of brook trout in eastern North America
(Danzmann et al. 1998, p. 1307). These mtDNA clades reflect historical isolation in glacial refugia or long periods of isolation in nonglacial areas in the southern part of the species' range. The Wisconsin glacial advance which covered portions of Canada covered all five Great Lakes 15,000 years ago (Bailey and Smith 1981, p. 1543). As these glaciers receded, brook trout recolonized the lakes from the Mississippi and
Atlantic refugia (Danzmann et al. 1998, pp. 1308, 1312). Given this pattern of glaciation, genetic diversity is greatest at the southern portion of the species' range and gradually decreases northward
(Danzmann et al. 1998, pp. 1310-1311). As the most geographically isolated (for tens of thousands of years), brook trout in the southern part of the species' range (along the Appalachian Mountains south to
Georgia) are the most diverse, containing all six mtDNA clades. The
Great Lakes contains three of the six mtDNA clades. Throughout the northern portion of their range in Canada, brook trout are the least genetically diverse, with only a single mtDNA clade present. Within each of these lineages, there is evidence to suggest that selection is driving rapid phenotypic divergence in some populations.
Results based on microsatellite DNA variation identified nine distinct genetic assemblages of brook trout in the U.S. (King 2009, unpub. data). Assemblages from the nonglacial southern part of the species' range (along the Appalachian Mountains from Pennsylvania to
Georgia) in the U.S. are the most genetically divergent, and this divergence among the assemblages generally decreases as the range progresses northward.
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Genetics of Brook Trout in the Great Lakes
Populations from Lake Superior and tributaries to Lake Erie form two of the nine genetic assemblages of brook trout in the U.S. The Lake
Erie populations are the most divergent assemblage from the northern part of the species' range. Lake Superior populations are similar in the degree of genetic divergence to the remaining northern assemblages grouping with the average genetic distance between brook trout populations in the U.S. Samples from the rest of the Great Lakes were not available for analysis. Although brook trout in the Great Lakes do not contain any wholly unique mtDNA clades, they do contain a large amount of the genetic variation in a confined portion of the range
(Danzmann et al. 1998, pp. 1310-1311).
Native populations of brook trout in Lake Superior in most cases have retained their native genetic characteristics despite the stocking of hatchery fish from sources outside and within the Lake Superior basin. In Lake Superior, the intensity and purpose of stocking has varied over time and space. For example, Minnesota tributaries to Lake
Superior have been stocked with hatchery strains that originated from outside of the Great Lakes Basin to provide fishing opportunities above fish passage barriers (Wilson et al. 2008, p. 1312). Until the early 1990s, most of the stocked fish in Lake Superior were domesticated strains from outside the Great Lakes basin (Schreiner et al. 2008, p. 1357), although many stocking events were undocumented and records of early stocking events are incomplete (Wilson et al. 2008, p. 1312).
These stocking efforts were not targeted at rehabilitation and from that perspective, results were poor. The stocked fish were not behaviorally or evolutionarily adapted to the environment in which they were planted, criteria known to limit survival and reproductive success
(Schreiner et al. 2008, p. 1357). Burnham-Curtis (2001, p. 2) concluded that hatchery fish have had little reproductive success in Lake
Superior streams based on her examination of 36 tributaries to Lake
Superior and 9 hatchery stocks outplanted into the lake. However, the genetic methods used by Burnham-Curtis provided low power to detect genetic introgression of hatchery fish into native populations (Wilson et al. 2008, p. 1312). A recent study by D'Amelio and Wilson (2008, p. 1215) used genetic methods with high power to detect genetic introgression of hatchery fish into natural populations. This study documented only low levels of genetic introgression of Lake Nipigon hatchery fish into native populations of brook trout from six tributaries to Lake Superior's Nipigon Bay (D'Amelio and Wilson 2008, p. 1222), despite decades of stocking. A study by Scribner et al.
(2006, pp. 3-4) examined nine brook trout populations from Lake
Superior tributaries on the south shore of Michigan and four hatchery strains outplanted into those tributaries. This study used similar methods to D'Amelio and Wilson (2008). Scribner et al. (2006, p. 8) concluded that hatchery stocking appears to have minimal if any impact of on brook trout.
Brook Trout Life-History Diversity
An individual's ability to produce multiple phenotypes (visible or observable characteristics) in response to its environment is termed phenotypic plasticity (Scheiner 1993, p. 36). Recent studies have recognized the role of phenotypic plasticity as a major source of phenotypic variation in natural populations (Price et al. 2003, p. 1438). The brook trout exhibits remarkable phenotypic plasticity across its natural range. This plasticity allows it to thrive in a variety of environments, from cold subarctic regions, through temperate zones and in southern refugia in eastern North America, and in a range of places where it has been introduced (Power 1980, p. 142). Although primarily a stream-dwelling species, brook trout also occupy inland lakes and coastal waters. Because of the variety of the freshwater, estuary, and ocean environments, migratory plasticity is also favored. The brook trout's dispersal subsequent to receding glaciation, and separation into isolated breeding stocks in diverse habitats subject to an array of natural and man-made influences have all contributed to this variability (Power 1980, p. 142).
Brook trout display considerable life-history variation throughout their native range (Huckins and Baker 2008, p. 1229). Brook trout across its range exhibit a variety of life-history types (polymorphisms or ecotypes), including fluvial (stream-dwelling), adfluvial (migrating between lakes and streams), lacustrine (lake-dwelling), and anadromous
(migrating from salt water to spawn in fresh water) forms.
Understanding life-history diversity in a species requires knowledge of the evolutionary history, ecological setting, and reproductive relationships among ecotypes. Reproductive interactions between ecotypes are reflected by the magnitude and pattern of genetic differentiation observed between life-history phenotypes at neutral genetic markers. The expression of migratory behavior (expressed as the adfluvial and anadromous ecotypes) by any individual fish will be partially in direct response to its environment. Phenotypic expression of more than one form may be expected in a population located in a variable environment containing habitats for several ecotypes. The amount of phenotypic plasticity a population will exhibit for the migratory trait also has a heritable genetic basis and will be determined by the intensity and type of selective pressures that population experiences (Via and Lande 1985, pp. 517-519; Theriault et al. 2008, pp. 418-419).
Adoption of migratory adfluvial form or stream-resident life- history form in brook trout has been modeled under a conditional strategy framework where environmentally influenced threshold traits determine which ecotype a fish will adopt (Hendry et al. 2004, pp. 124- 125). Growth rate efficiencies, body size, and concentration of juvenile hormone have all been identified as potential threshold traits
(Theriault and Dodson 2003, pp. 1155-1157). Theoretical work by Ridgway
(2008, p. 1185) and Uller (2008, pp. 436-437) also provide information to suggest parental effects are important to the expression of alternate ecotypes of brook trout. These parental effects describe an affect of the parental phenotype on the offspring's phenotype such as coaster females producing larger eggs and spawning in different locations from stream-resident ecotypes, influencing the habitat use
(Morinville and Rasmussen 2006, pp. 701-702) and growth rate at the juvenile stage (Perry et al. 2005, p. 1358). These differences in growth rate and habitat use impact potential threshold traits.
Work on sympatric brook trout life forms at young ages largely comes from a few studies on anadromous populations. Morinville and
Rasmussen (2003) studied the bioenergetics of young brook trout exhibiting anadromous migratory and stream-resident life tactics. They found that the anadromous migrants have higher metabolic costs and had consumption rates 1.4 times that of stream residents but growth efficiencies of the anadromous form were lower than that of residents.
Spatial utilization of habitat differed among the life tactics as well, with migratory individuals occupying faster-flowing waters compared to the resident fish which used pool areas (p. 408). They concluded that migrant brook trout have noticeably different energy budgets than resident brook trout from the same system (p. 406). Morinville and
Rasmussen (2008) also investigated morphological differences between life
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tactics. The authors concluded that migrant brook trout were found to be more streamlined (narrower and shallower bodies) than resident brook trout, and these differences persisted into the marine life of the migrant fish (pp. 175, 183). The differences were powerful enough to derive discriminant functions using five of the measured traits allowing for accurate classification of juvenile brook trout as either migrant or resident with an overall correct classification rate of 87 percent.
A study by Theriault et al. (2007b, p. 61) found that sympatric anadromous and fluvial brook trout in the Sainte-Marguerite River in
Quebec belonged to a single gene pool. Phenotypic plasticity is, therefore, a major force driving the expression of these two life histories from this population. Evolution of phenotypic plasticity in this population was influenced by mating systems with most of the mating between different morphotypes occurring between fluvial males and anadromous females. Additional work in this system demonstrated significant heritability for life-history tactic and for body size
(Theriault et al. 2007a, pp. 7-8) indicating expression of life-history tactic in this population can be effected by natural or artificial selection.
Life-History Diversity in Great Lakes Brook Trout
Fish that complete their life cycle exclusively in tributaries to the Great Lakes exhibit the fluvial life history and are defined as stream residents. ``Coaster'' (the subject of the petition) is a regional term for a life-history variant of brook trout in the Great
Lakes (Burnham-Curtis 2001, p. 2; Wilson et al. 2008, p. 1) which use lake waters of the Great Lakes for all or a portion of its life cycle
(Becker 1983, p. 320). The coaster form can be further divided into an adfluvial ecotype that migrates from the stream to the lake and back into tributaries to spawn and a lacustrine ecotype that completes its life cycle entirely within the lake (Huckins et al. 2008, p. 1323). In the Great Lakes region, spawning usually occurs from mid-September through mid-November. Distinct life histories associated with the coaster and stream-resident types result in different physical, demographic, and ecological characteristics for the forms (Huckins et al. 2008, p. 1337; Huckins and Baker 2008, p. 1241; Ridgway 2008, p. 1185). Specifically, coasters tend to live longer than stream residents
(5-8 years versus less than 5 years), reach maturation later (females at 2-4 years versus 1-2 years), attain larger length and weight as adults (12-25 inches and 0.75-8 pounds (30-64 centimeters (cm) and 341- 3632 grams (g)) versus (5-15 inches (13-38 cm) and (less than 1 pound
(
