Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Monongahela River Basin Population of the Longnose Sucker as Endangered

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Notice of 90-day petition finding.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), announce a 90-day finding on a petition to list the Monongahela River Basin population of Catostomus catostomus (longnose sucker) as endangered under the Endangered Species Act of 1973, as amended (Act). We find that the petition does not present substantial scientific or commercial information indicating that listing C. catostomus may be warranted. This finding is based on our determination that there is insufficient evidence to indicate that the Monongahela River Basin population of C. catostomus represents a distinct population segment (DPS) and, therefore, it cannot be considered a listable entity under section 3(15) of the Act. Accordingly, we will not initiate a status review in response to this petition. However, the public may at any time submit to us information concerning whether the Monongahela River Basin population of Catostomus catostomus meets the DPS criteria for this otherwise widespread species.

DATES:

The finding announced in this document was made on March 8, 2007.

ADDRESSES:

The complete file for this finding is available for public inspection, by appointment, during normal business hours at the Pennsylvania Field Office, U.S. Fish and Wildlife Service, 315 South Allen Street, Suite 322, State College, PA 16801. Submit new information, materials, comments, or questions concerning the status of or threats to this taxon to us at the above address.

FOR FURTHER INFORMATION CONTACT:

David Densmore, Supervisor, Pennsylvania Field Office, U.S. Fish and Wildlife Service (see ADDRESSES) (telephone 814-234-4090; facsimile 814-234-0748).

SUPPLEMENTARY INFORMATION:

Background

Section 4(b)(3)(A) of Act (16 U.S.C. 1531 et seq.) requires that we make a finding on whether a petition to list, delist, or reclassify a species presents substantial scientific or commercial information to indicate that the petitioned action may be warranted. We are to base this finding on information provided in the petition, supporting information submitted with the petition, and information otherwise available in our files at the time we make the determination. To the maximum extent practicable, we are to make this finding within 90 days of our receipt of the petition, and publish our notice of this finding promptly in the Federal Register.

Our standard for substantial information within the Code of Federal Regulations (CFR) with regard to a 90-day petition finding is “that amount of information that would lead a reasonable person to believe that the measure proposed in the petition may be warranted” (50 CFR 424.14(b)). If we find that substantial information was presented, we are required to promptly commence a review of the status of the species.

In making this finding, we relied on information provided by the petitioners and otherwise available in our files at the time of the petition review and evaluated this information in accordance with 50 CFR 424.14(b). Our process of making a 90-day finding under section 4(b)(3)(A) of the Act and section 424.14(b) of our regulations is limited to a determination of whether the information in the petition meets the “substantial information” threshold. Unless otherwise noted, the following summary regarding the species, its distribution, and taxonomy was provided in the petition.

Petition

On December 27, 2002, we received a formal petition from the Fisheries Technical Committee of the Pennsylvania Biological Survey to list a population of longnose sucker (Catostomus catostomus), that is restricted to the Monongahela River Basin, as an endangered species under section 4 of the Act. The petition also requested that subsequent to listing, the Service make a definitive determination of the population's taxonomic status, address direct and potential threats, investigate life history, and reintroduce the species within its historic range in the Monongahela River Basin.

Action on the petition was precluded by court orders and settlement agreements for other listing actions that required nearly all of our listing funds for fiscal year 2003. A letter was sent to the petitioners on January 17, 2003, acknowledging receipt of the petition and explaining the reasons for the delay in processing.

Species Information

Catostomus catostomus, or longnose sucker, is a member of the family Catostomidae, a group of freshwater, principally substrate foraging fishes. This species was described by Forster in 1773, based on specimens collected from tributaries to the Hudson Bay. The subject of the petition is a disjunct population that occurs in the Monongahela River drainage in West Virginia, western Maryland, and southwestern Pennsylvania. This southern population is geographically separated from the larger range of the fish. According to the petition, no other populations are known from the Ohio River drainage, or any other Mississippi River basin tributaries, excepting the Missouri River (Gilbert & Lee, 1980; Page and Burr, 1991).

The petition utilizes several references regarding longnose sucker life history and habitat (e.g., Harris 1962; Becker 1983; Cooper 1983; Geen et al., 1966; Smith 1985). None are specific to longnose suckers in the Monongahela River system, but present general information concerning longnose sucker habitats and life history. Longnose suckers occur in clear, cold waters throughout much of northern North America and parts of eastern Asia. Those in the Monongahela River Basin generally occur in small to medium-sized streams, most often in deeper pools with either boulder-rubble substrate or a significant amount of coarse, woody debris. These pools and runs (streams) are usually immediately below faster-flowing riffle areas. On the basis of available information, the Monongahela River population occurs primarily in clear, cool streams, which appear to be consistent with habitats utilized elsewhere throughout its range.

The petitioners do not reference specific studies regarding reproductive behavior of the longnose sucker population in the Monongahela River Basin, but the species has been documented to spawn in water temperatures ranging from 10 to 15 degrees Celsius (50 to 59 degrees Fahrenheit), with schools of the fish gathering over gravel substrates in stream riffles and lake shoals. Longnose suckers exhibit high fecundity, with egg counts ranging from 17,000 to more than 60,000 per female. Annual survival of eggs and fry is low, leading to low annual recruitment into juvenile age classes. The species has been documented to begin to reach maturity at 4 years of age for males and 5 years of age for females in western Lake Superior. Longnose suckers exhibit some variation in mature size across their range; the largest individual recorded was a 642 millimeter (mm) (25.3 inches) female estimated to be 19 years old from Great Slave Lake, Northwest Territories, Canada. Populations of apparently “stunted” individuals have also been reported in parts of the species’ range. Whether environmentally influenced or genetic, the largest specimen recorded from the Monongahela River drainage is less than 250 mm.

Distribution

The longnose sucker is among the most widely distributed of North American freshwater fishes, ranging, in the east from western Labrador and Quebec; south to West Virginia; west to Nebraska, Colorado, and Washington; and north throughout most of Alaska and Canada, including the Arctic and extending into eastern Siberia. The Monongahela River drainage in West Virginia, western Maryland, and southwestern Pennsylvania supports the disjunct population that is the subject of the petition.

The petition reports 39 collection records for the longnose sucker from the Monongahela River Basin (with references including Jordon 1878, Goldsborough and Clark 1908, and Hendricks 1980). With the exception of a collection record from the Tygart Valley River, West Virginia, and the Youghiogheny River (a Monongahela River tributary), Allegheny County, Pennsylvania, longnose sucker collection records are restricted to a Youghiogheny River tributary drainage, the Casselman River Basin in Garrett County, Maryland and Somerset County, Pennsylvania. The most recent reported collection from Maryland was in 1978, and the species is considered to be extirpated from the State (Maryland Department of Natural Resources 2004). The petition concludes that since 2000, longnose suckers have only been collected in the Monongahela River Basin in Pennsylvania within reaches of four Casselman River tributary streams: Elklick Creek, Flaugherty Creek, Piney Creek, and Whites Creek.

Taxonomy

The petition references McPhail and Taylor (1990) in asserting that across the species' range, longnose suckers are morphologically variable, with some evidence of eastern and western divergence across North America. However, no such variation is described for the population in the Monongahela River Basin. The Monongahela River Basin is geographically separated from other waters supporting this species by a watershed divide; the closest population is the one that occurs in the Lake Erie Basin, more than 257 kilometers (km) (160 miles (mi)) to the north. The petitioners present information that theorizes that longnose suckers in the Monongahela River Basin became isolated from the main populations to the north through stream capture and changing flow patterns that occurred during the Wisconsin glacial retreat, and that this subpopulation may have persisted in the Monongahela River Basin for 15,000 years or more. The petitioners suggest that this period of isolation may have resulted in genetic differences from other longnose sucker populations. They indicate that the Salish sucker, a longnose sucker population native to the Frazier River and Puget Sound, Canada, appears to be genetically distinct from other northwestern longnose suckers. The petition uses this example to suggest that the Monongahela River population of the longnose sucker may also be genetically distinct from other longnose sucker populations. However, the petition does not present any genetic data or other specific information to support this hypothesis. Rather, the petition specifically requests that the Service make a “definitive determination of its taxonomic status.”

Distinct Vertebrate Population Segments

The petitioners have asked us to consider listing the longnose sucker in the Monongahela River Basin in Pennsylvania, Maryland, and West Virginia as endangered. Under the Act, we can consider for listing any species, subspecies, or distinct population segment (DPS) of any species of vertebrate fish or wildlife that interbreeds when mature, if information is substantial to indicate that such action may be warranted. To implement the measures prescribed by the Act and its Congressional guidance (see Senate Report 151, 96th Congress, 1st Session), we developed a joint policy with the National Oceanic and Atmospheric Administration entitled “Policy Regarding the Recognition of Distinct Vertebrate Population Segments under the Act” (61 FR 4725; February 7, 1996). According to the Service's policy on distinct vertebrate population segments, the three elements considered regarding the potential recognition of a DPS as endangered or threatened are: (1) The discreteness of the population segment in relation to the remainder of the species to which it belongs; (2) the significance of the population segment to the species to which it belongs; and (3) the population segment's conservation status in relation to the Act's standards for listing (i.e., when treated as if it were a species, is the population segment endangered or threatened?). Following is our evaluation of these elements in relation to the petitioned entity, the longnose sucker in the Monongahela River Basin.

Discreteness: A population segment of a vertebrate species may be considered discrete if it is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors, or if 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) of the Act.

The petition states that the longnose sucker population in the Monongahela River Basin is the only population of this species recorded from the Ohio River Basin, and is markedly separated from the rest of the species' range, with the nearest population occurring across a major watershed boundary in the Lake Erie Basin at least 265 km (160 mi) to the north (Gilbert and Lee 1980; Page and Burr 1991). The petition further hypothesizes that the population in the Monongahela River Basin appears to be a glacial relic and may have been separated from the larger range of the species as much as 15,000 years ago (Hendricks et al. 1983). On the basis of a review of the information centered within the petition, we find that the petition presents substantial evidence to indicate that the species is markedly separated from other populations of the same taxon by physical factors. Therefore, we conclude that the longnose sucker population in the Monongahela River Basin meets the “discreteness” criterion.

Significance: If a population segment is considered discrete under one or more of the conditions listed in the Service's DPS policy, its biological and ecological significance will then be considered in light of Congressional guidance that the authority to list DPS's be used “sparingly” while encouraging the conservation of genetic diversity. In carrying out this evaluation, the Service considers available scientific evidence of the potential DPS's importance to the taxon to which it belongs. This consideration may include, but is not limited to: (1) Persistence of the DPS in an ecological setting unusual or unique for the taxon; (2) evidence that loss of the DPS would result in a significant gap in the range of a taxon; (3) evidence that the DPS represents the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historic range; or (4) evidence that the DPS differs markedly from other populations of the species in its genetic characteristics. Each of these factors is discussed below, based on the information presented in the petition.

Persistence of the population segment in an ecological setting that is unique for the taxon. Longnose suckers in the Monongahela River Basin appear to use habitat that is similar to stream habitats used by the species throughout its range. Although situated geographically to the south, the ecological setting is consistent with habitats described elsewhere in the species' range (i.e., cool, clear streams with gravel and cobble substrates). Therefore, on the basis of information provided in the petition, it is our determination that the Monongahela River population does not appear to exist in either an unusual or unique setting for the species.

Loss of the population segment would result in a significant gap in the range of taxon. Both the historic, and current, range of longnose suckers in the Monongahela River Basin represents a very small percentage (less than one percent) of the species' overall global range. While the loss of this population would eliminate the species from the Monongahela River drainage, the species would continue to exist in over 99 percent of its range. As a result, we do not believe that a significant gap in the species' range would result. Furthermore, neither the petition nor information in our files indicates that loss of this population would result in a significant gap at the edge of the species range.

The population segment represents the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historical range. The Monongahela River population of the longnose sucker does not represent the only surviving natural occurrence of this species. According to the petition, the longnose sucker survives naturally throughout much of northern North America. Therefore, we have determined that this criterion is not relevant to this evaluation.

The discrete population segment differs markedly from other populations of the species in its genetic characteristics. The petitioners speculate that longnose suckers from the Monongahela River Basin may be genetically distinct from longnose sucker populations to the north and west, and suggest that this population may be “stunted.” The petitioners suggest that because the Salish sucker (Catostomus catostomus), appears to be genetically distinct from longnose sucker populations elsewhere in the Frazier River and Puget Sound, Canada, that genetic differences may also exist between the Monongahela River Basin population of the longnose sucker and longnose suckers elsewhere. However, no data regarding quantitative or morphological analysis or literature citations were presented to support the genetic distinctiveness of the Monongahela River population of the longnose sucker, and the petition recommends that such studies be initiated. Therefore, on the basis of a review of the information provided in the petition, we have determined that there is insufficient evidence to suggest that the Monongahela River population of the longnose sucker differs markedly from other populations of the longnose sucker.

Based on an evaluation of each of the criteria identified in the Service's DPS policy under significance relative to the information provided in the petition, we have determined that the Monongahela River Basin population of the longnose sucker does not meet the “significance” criterion under the Service's DPS policy. Because the Monongahela River Basin population of the longnose sucker fails to meet one of the first two criteria for a distinct vertebrate population segment per our policy (i.e., the significance criterion), we have determined that it is not a listable entity under the Act. We note that the petition also fails to present substantial information that the range of the longnose sucker within the Monongahela River Basin may be a significant portion of the range of the species. Therefore, we are not proceeding with an evaluation of its conservation status relative to the Act's standards for listing as endangered or threatened.

The petition presented information for the five listing factors in section 4 of the Act in an effort to identify threats that may be leading to the decline of the Monongahela River population of the longnose sucker. These factors are pertinent only in cases where the organism being proposed for listing is a listable entity as defined by section 3(15) of the Act. Because the Monongahela River basin population does not meet the significance criterion for a DPS, and therefore not a listable entity, the five threat factors are not analyzed for that population here.

Finding

We have reviewed the information presented in the petition, and evaluated that information in relation to information readily available in our files. Based on this review, we find the petition does not present substantial information indicating that listing the Monongahela River population of C. catostomus may be warranted. This finding is based on the lack of evidence to indicate that the Monongahela River population of C. catostomus meets the criteria for being classified as a DPS. Although it is geographically and reproductively isolated, scientific evidence was not provided to document this population's biological or ecological significance under the Service's DPS policy. Therefore, we have concluded that the Monongahela River population of the longnose sucker is not a listable entity under section 3(15) of the Act. We will not commence a status review in response to this petition. We encourage interested parties to monitor the Monongahela River population's status and trends, and potential threats, and to implement actions that will contribute to this species' conservation. We also encourage interested parties to continue to gather data that will assist with these conservation efforts. New information regarding this population's potential consideration as a DPS should be submitted to the Field Supervisor, Pennsylvania Field Office (see ADDRESSES).

References Cited

A complete list of all references cited herein is available, upon request, from the Pennsylvania Field Office, U.S. Fish and Wildlife Service (see ADDRESSES).

Author

The primary author of this notice is Robert M. Anderson, Pennsylvania Field Office (see ADDRESSES).

Authority

The authority for this action is section 4 of the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).