19910 Federal Register / Vol. 66, No. 75 / Wednesday, April 18, 2001 / Proposed Rules
ENVIRONMENTAL PROTECTION SUPPLEMENTARY INFORMATION: For River basin and the Mississippi River AGENCY further information, please see the downstream from the confluence with information provided in the direct final the Missouri River. Both species are 40 CFR Part 52 action, with the same title, located in highly adapted for conditions found in [PA106–4113b; FRL–6959–7] the ‘‘Rules and Regulations’’ section of large free-flowing rivers with relatively this Federal Register publication. high levels of turbidity. The sicklefin chub is usually Approval and Promulgation of Air Dated: March 19, 2001. yellowish or tan colored on the back Quality Implementation Plans; William C. Early, Pennsylvania; Approval of VOC and and silvery-white on the belly with a Acting Regional Administrator, Region III. NOX RACT Determinations for Merck snout protruding slightly beyond the and Company, Inc [FR Doc. 01–9481 Filed 4–17–01; 8:45 am] mouth. A single pair of maxillary BILLING CODE 6560–50–U barbels is located at the corners of the AGENCY: Environmental Protection mouth. Average adult length ranges Agency (EPA). from 3.6 to 10.1 centimeters (1.4 to 4.0 ACTION: Proposed rule. DEPARTMENT OF THE INTERIOR inches) with the average adult weight ranging from 0.6 to 6.2 grams (0.02 to SUMMARY: EPA proposes to approve the Fish and Wildlife Service 0.2 ounce). The sicklefin is a relatively State Implementation Plan (SIP) short-lived species with a small revision submitted by the 50 CFR Part 17 percentage of the population reaching Commonwealth of Pennsylvania for the age 4. The sicklefin chub can be most purpose of establishing and requiring Endangered and Threatened Wildlife readily distinguished by its elongated reasonably available control technology and Plants; 12-month Finding for a pectoral fins and a sickle-shaped dorsal (RACT) for a facility of Merck and Petition To List the Sicklefin Chub fin. Company, Inc. located in Montgomery (Macrhybopsis meeki) and the The sturgeon chub is tan to pale green County. This facility is a major source Sturgeon Chub (Macrhybopsis gelida) on the back and cream to white on the of volatile organic compounds (VOC) as Endangered belly. A few black speckles occasionally and nitrogen oxides ( NOX). In the Final are present on the sides and back. It has Rules section of this Federal Register, AGENCY: Fish and Wildlife Service, Interior. a long, fleshy snout with a single pair EPA is approving the Commonwealth’s of maxillary barbels located at the ACTION: Notice of 12-month petition SIP submittal as a direct final rule corners of the mouth. Average adult finding. without prior proposal because the length ranges from 3.8 to 9.6 centimeters Agency views this as a noncontroversial SUMMARY: We, the U.S. Fish and (1.5 to 3.8 inches) and average adult submittal and anticipates no adverse Wildlife Service, announce a 12-month weight ranges from 0.3 to 9.3 grams comments. A detailed rationale for the finding for a petition to list the sicklefin (0.01 to 0.3 ounces). The sturgeon chub approval is set forth in the direct final is relatively short-lived species with a rule. If no adverse comments are chub (Macrhybopsis meeki) and the sturgeon chub (Macrhybopsis gelida) as maximum life-span of about 4 years. received in response to this action, no Sturgeon chub can be identified by the further activity is contemplated. If EPA endangered under the Endangered Species Act of 1973, as amended. After unique longitudinally-arranged ridges or receives adverse comments, the direct keels on most scales. final rule will be withdrawn and all review of all available scientific and commercial information, we find that Section 4(b)(3)(B) of the Endangered public comments received will be Species Act of 1973 (Act), as amended addressed in a subsequent final rule listing either of these two species is not warranted at this time. (16 U.S.C. 1531 et seq.), requires that based on this proposed rule. EPA will within 90 days of receipt of the petition, not institute a second comment period. DATES: The finding announced in this document was made on April 10, 2001. to the maximum extent practicable, we Any parties interested in commenting make a finding on whether a petition to ADDRESSES: on this action should do so at this time. Data, information, list, delist, or reclassify a species DATES: Comments must be received in comments, or questions regarding this presents substantial scientific or writing by May 18, 2001. notice should be sent to Mr. Allyn Sapa, commercial information indicating that ADDRESSES: Written comments should Field Supervisor, 3425 Miriam Avenue, the requested action may be warranted. be addressed to Makeba Morris, Chief, Bismarck, North Dakota, 58501. The If the petition contains substantial Permits and Technical Assessment complete administrative file for this information, the Act requires that we Branch, Air Protection Division, finding is available for inspection initiate a status review of the species Mailcode 3AP11, U.S. Environmental during normal business hours, by and publish a 12-month finding Protection Agency, Region III, 1650 appointment, at the above address. The indicating whether the petitioned action Arch Street, Philadelphia, Pennsylvania status review document for the sicklefin is (a) not warranted, (b) warranted, or (c) 19103. Copies of the documents relevant chub and the sturgeon chub also may be warranted but precluded from to this action are available for public obtained at that address, or at our immediate listing proposal by other inspection during normal business Internet web site at
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sicklefin and sturgeon chubs as sicklefin chub and sturgeon chub Since 1993, when we completed a endangered throughout their range in populations and to determine whether Sicklefin Chub Status Report (U.S. Fish accordance with the provisions of the listing these species as threatened or and Wildlife Service 1993a), additional Act. The petitioners include American endangered under the Act was surveys have been conducted Rivers, Environmental Defense Fund, warranted. A draft 12-month finding throughout most of this species’ Mni Sose Intertribal Water Rights was completed in August 1995 and historical range. These studies indicate Coalition, National Audubon Society, subsequently revised in 1997, 1999, and that sicklefin chub are more widely and the Nebraska Audubon Council. 2000, to include substantial new distributed and more common than The petitioners assert that, information. The Montana Rivers previously believed. The effectiveness historically, sicklefin chub and sturgeon Coalition filed a 60-day notice of intent of sampling techniques has dramatically chub populations inhabited a to sue the Secretary of the Interior on improved with the use of benthic trawls substantial portion of the Missouri April 6, 2000, for the Service’s alleged that have been modified to collect small River, its larger tributaries, and the failure to act on the petition in the fish. Benthic trawls have permitted Mississippi River downstream from the timeframes established by the Act. The sampling in deep-water habitats where confluence with the Missouri River. Montana Rivers Coalition’s action seines, the traditional cyprinid They indicate that the historic range of resulted in a settlement agreement in collection method, are ineffective or sicklefin and sturgeon chubs included which we agreed to submit the 12- cannot be used. waters in or bordering 13 and 14 States, month finding for the sicklefin and Recent studies using benthic trawls respectively. sturgeon chubs for publication in the indicate that sicklefin chub comprise a The petitioners indicate that sicklefin Federal Register on or before April 12, significant part of the fish population at and sturgeon chubs have physically 2001. three locations in the Missouri River adapted through evolution to inhabit We received information concerning drainage—above Fort Peck Reservoir in turbid, swift-flowing rivers. The the status of sicklefin and sturgeon chub Montana; the Yellowstone/Missouri petitioners assert that the impoundment populations from State game and fish River confluence area in North Dakota and channelization of the Missouri departments, the U.S. Bureau of and Montana; and the lower Missouri River have drastically altered the Reclamation, U.S. Geological Survey, River in Missouri. Grisak (1996) used natural habitat of the chubs by altering tribal representatives, universities, and both seines and a benthic trawl to the natural hydrograph and reducing other organizations and individuals. We sample the fish population in the water temperature and turbidity levels. Missouri River above Fort Peck also reviewed information on the The petitioners also contend that Reservoir in 1994 and 1995. He found sicklefin and sturgeon chub from peer- aquatic insect larvae are the primary sicklefin chubs comprised 21.9 percent reviewed journal articles, agency reports food source for these species. They of the benthic trawl catch and only 0.08 and file documents, telephone believe the removal of snags from the percent of the catch with seines. interviews, and written correspondence Missouri River and dam construction Sicklefin chubs were the second most with fisheries biologists familiar with have affected the range and abundance common species collected in benthic these species. of aquatic insect larvae. trawl tows. In 1999 and 2000, Gardner The petitioners conclude that the Around the time the petition to list (2000a,b) sampled the same general area reduction of sicklefin chub and sturgeon the sicklefin and sturgeon chubs as as Grisak. The sicklefin chub was the chub habitat has severely impacted the endangered was filed, fishery biologists most common species collected in 1999 species ability to survive. modified the gear used to sample (41.5 percent of the catch) and the third Transformation of the Missouri River cyprinid populations. Until 1993, most common species collected in 2000 has created colder, less turbid researchers primarily relied on seines to (5.1 percent of the catch). Welker (2000) conditions which favor other Missouri collect small fish in the Missouri and used both seines to sample shallow River fish. The petitioners assert that the Mississippi Rivers. Seines allowed border channel habitat and a benthic existing programs are not adequate to sampling in shallow water, usually not trawl to sample deep-water habitat in protect sicklefin and sturgeon chub exceeding 1.5 meters (4.9 feet) in depth, the Yellowstone/Missouri River populations. They believe listing these in sandbar and border channel habitats. confluence area in 1997 and 1998. species as endangered will ensure Grisak (1996) was the first to use a Sicklefin chubs were the most common consultation under section 7 of the Act benthic trawl, modified to catch small species collected in benthic trawl tows, for actions authorized, funded, or fish, to characterize the fish population comprising 33.2 percent of the trawl carried out by Federal agencies. The in a portion of the Missouri River. catch. By contrast, only 12 sicklefin petitioners also indicate that scientists Grisak’s work above Fort Peck Reservoir chub were collected in seine hauls desperately need more information in Montana during 1994 and 1995 and (0.005 percent of the catch using seines). about both species and listing will place the results of subsequent field Liebelt (in litt. 1999) sampled the a higher priority on funding sicklefin investigations using benthic trawls have Missouri River above the headwaters of and sturgeon chub research needs. provided new information on the range Lake Sakakawea in 1999. Sicklefin and relative abundance of the sicklefin chubs were the third most common Status Review and sturgeon chubs. species collected, making up 8.6 percent On January 18, 1995, we published a Sicklefin Chub Status Summary of the catch. Grady and Milligan (1998) positive 90-day finding for both species sampled the Missouri River in Missouri in the Federal Register indicating that Based on our current understanding in 1997. They collected 3,934 fish in the petitioned action may be warranted. of this species, we believe that the seine hauls, including 1 sicklefin chub. At that time, we requested public sicklefin chub historically occurred in By contrast, sicklefin chubs were the comments on the 90-day finding and approximately 85 miles of the Lower second most common species collected any available information on the status Yellowstone River, approximately 1,950 with a benthic trawl (8.4 percent of the of the species. We established a status miles of the main stem Missouri River, catch). assessment team, consisting of biologists and about 1,150 miles of the Mississippi In addition to the Missouri River from Service Regions 3, 4, and 6, to River, below the mouth of the Missouri populations, field studies conducted by gather information documenting River. the Missouri Department of
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Conservation since 1997 have of the catch) in benthic trawl samples a significant portion of its range. An documented viable populations of taken in the main channel. Shallow ‘‘endangered species’’ is defined as any sicklefin chub in the Middle Mississippi border channel areas also were sampled species which is in danger of extinction River and in the Wolf Island area of the with seines. Sturgeon chubs were rare in throughout all or a significant portion of Lower Mississippi River. Prior to these seine samples, representing less than its range. studies, collections of sicklefin chub in 0.01 percent of the catch. Liebelt (in litt. Section 4(a) of the Act describes five the Lower Mississippi River were rare 1999) sampled a reach of the Missouri threat factors that we must consider to and generally document the presence of River from Williston, North Dakota, determine whether any species is a an individual fish. downstream to the headwaters of Lake threatened or endangered species for Based on the information provided by Sakakawea in August 1999. Sturgeon purposes of the Act. Any one or these surveys, we now estimate that chubs were the second most common combination of the five threat factors sicklefin chub currently occupy species collected, representing 11.1 may indicate the appropriateness of a approximately 1,110 miles or about 54 percent of the catch in benthic trawl warranted 12-month administrative percent of the species’ historic range in tows. In Missouri, Grady and Milligan finding. Section 4(b) of the Act requires the Missouri River drainage. (1998) sampled the Lower Missouri that we also give consideration in our determination of a species’ status to Sturgeon Chub Status Summary River with seines and benthic trawls in 1997. They collected 3,934 fish with efforts being made by any State or We believe that the sturgeon chub seines; however, no sturgeon chub were foreign nation to protect such species. historically occurred in approximately captured. Sturgeon chub ranked fourth We considered the five threat factors 2,100 miles of the main stem Missouri in abundance for fish collected in established by the Act and any ongoing River and about 1,150 miles of the main benthic trawl tows (4.1 percent of the conservation measures for sicklefin and stem Mississippi River. The species also catch). sturgeon chubs in our determination. A was found in the Yellowstone River in Since 1997, field studies conducted full discussion of the threats appears in Montana and North Dakota and 30 by the Missouri Department of the current status review (U.S. Fish and tributaries to the Yellowstone and Conservation indicate a viable Wildlife 2001) for these species, and is Missouri Rivers. The sturgeon chub population of sturgeon chub exists in summarized as follows: occurred in portions of four tributaries the Middle Mississippi River and in the 1. The present or threatened in Wyoming, nine in Montana, five in Wolf Island area of the Lower destruction, modification, or North Dakota, six in South Dakota, six Mississippi River (Hrabik and Herzog, curtailment of the species habitat or in Nebraska, and four in Kansas. in litt. 2000 a,b). Historic collections of range. Tributaries such as the Powder River, sturgeon chub in the Lower Mississippi Water development projects on the which provides sturgeon chub habitat in River below Wolf Island are rare and do Missouri and Middle and Lower both Wyoming and Montana, are not provide adequate information to Mississippi Rivers and tributaries have included in the tallies for both States. assess if this area historically provided impacted sicklefin and sturgeon chub Other tributaries that historically important sturgeon chub habitat. populations. Reservoirs flooded river provided sturgeon chub habitat in two Using these studies we believe the habitat, altered temperature and flow states include the Big Horn, Little distribution of sturgeon chub in the regimes, and reduced sediment Missouri, and Republican Rivers. main stem Missouri and Mississippi transport and turbidity. Dams Studies conducted since 1994 using Rivers is similar to that of the sicklefin fragmented populations and restricted benthic trawls designed to collect small chub. Like the sicklefin chub, sturgeon movement. Channelization straightened fish from deep-water areas of the border chub comprise a significant portion of and narrowed river habitat, reduced and main channel have provided new the Missouri River fish community habitat diversity, and reduced overbank information about the distribution and above Fort Peck Reservoir in Montana, flooding. These impacts have resulted in relative abundance of sturgeon chub. in the Yellowstone/Missouri River a reduction in the range of these species Grisak (1996) conducted the first studies confluence area in Montana and North by approximately one half. using a benthic trawl with small mesh Dakota, and in the Lower Missouri River There are potential impacts associated netting to specifically collect cyprinids in Missouri. with coalbed methane production in and other small fish in the Missouri In total, we estimate that sturgeon Wyoming and Montana, and future River. He sampled the Missouri River chub currently occupy approximately water impoundment and depletion above Fort Peck Reservoir in 1994 and 1,155 miles or about 55 percent of the projects on the Yellowstone River, its 1995 and found that sturgeon chub species, historic range in the Missouri tributaries, and tributaries to the comprised 18.9 percent of the benthic River. The species also continues to be Missouri River. Information trawl catch compared to only 0.16 found in 11 of 30 tributaries to the documenting how coalbed methane percent of the catch with seines. In Yellowstone and Missouri Rivers that products will affect water quality in Grisak’s study, sturgeon chub were the have been documented as providing tributaries such as the Powder River is third most common species collected in sturgeon chub habitat. Viable not known at this time. The amount of benthic trawl tows. In 1999 and 2000, populations of sturgeon chub are also water involved with the potential Gardner (1999, 2000) sampled the same present in the Middle Mississippi River depletions is not of a sufficient general area as Grisak. Gardner collected and in the Wolf Island area of the Lower magnitude to suggest major impacts to 218 sturgeon chub (16.1 percent of the Mississippi River. As with the sicklefin the chubs. The impact of these projects catch) in August 1999 and 145 sturgeon chub, information documenting on aquatic ecosystems will be chub (32.0 percent of the catch) in sturgeon chub populations in the investigated further during the planning August 2000 using a benthic trawl. Mississippi River is limited by and permitting process. Welker (2000) used both seines and a comparison to the Missouri River data Although the chubs have suffered benthic trawl to sample the fish set. reductions in range, our status survey population in the Yellowstone/Missouri The Act defines a ‘‘threatened determined that both species currently River confluence area in North Dakota. species’’ as any species which is likely have a wider distribution than Sturgeon chub were the second most to become an endangered species within previously thought, and there are common species collected (32.3 percent the foreseeable future throughout all or numerous populations that appear to be
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viable throughout the range of both Tennessee prohibits the take or Another potential threat to sicklefin species. Channelization projects possession of either chub, or the and sturgeon chub populations is the continue to be implemented in the knowing destruction of habitats from presence of four species of Asian carp Missouri River Basin, but at a pace Federal actions (Bob Hatcher, Tennessee in the Mississippi River and the much reduced from the levels Wildlife Resource Commission, pers. Missouri River below Gavins Point Dam. experienced in the first half of the 20th comm. 1995). There are no data currently available to century. The construction of new large Several national and State document that chubs are being impacted reservoirs is not anticipated. The fact professional conservation societies and by invasive species. However, if Asian that these short-lived fish are clearly environmental departments within carp populations continue to expand, reproducing where stream habitat various State governments unofficially the diversity of species supported by the conditions are adequate leads us to have classified the sturgeon chub and Missouri and Mississippi River conclude that neither species will sicklefin chub as either threatened or ecosystems, including chubs, may be become threatened or endangered in the endangered, a species of special negatively impacted. foreseeable future due to habitat loss. concern, rare, on a watch list, deemed Conservation Measures 2. Overutilization for commercial, in need of management, or transient. recreational, scientific, or educational However, these designations do not We also have evaluated ongoing and purposes. provide any legal protection to either proposed conservation measures that We are not aware of any significant chub species. will have a beneficial impact on sicklefin and sturgeon chub populations threats to either species in this category. 5. Other natural or manmade factors when fully implemented. We have However, removal of individuals from affecting its continued existence. the wild could have occurred and may identified two conservation actions, one Severe drought in the early 1990’s continue to occur from harvest of bait that is being implemented and one that may have eliminated sturgeon chub fish. We find no evidence of significant is currently in the planning stage, that from some Missouri River tributaries impacts to the chub species from will benefit both sicklefin and sturgeon and may reoccur and impact additional overutilization for commercial, chubs. Implementation and monitoring tributary populations. Sturgeon chub recreational, scientific, or educational of the Missouri River Bank Stabilization populations have been eliminated from purposes. and Navigation Project (BSNP) fish and 3. Disease or predation. approximately 800 miles of the Missouri wildlife mitigation plan is ongoing. The No diseases are currently known to River that has been converted to BSNP was established to create a threaten the species. Predation has reservoir habitat. Tributaries that now navigable channel from Sioux City, likely increased over historic levels due flow into reservoirs may never naturally Iowa, to the mouth of the Missouri River to stocking of piscivorous fish into the recolonize. However, our status review near St. Louis (735 river miles). reservoirs and remaining riverine found that there are numerous viable Originally authorized by the Rivers and sections. Reduced turbidity levels in populations of both species currently Harbors Act of 1912 and officially chub habitat also may have resulted in extant throughout about half of the completed in 1981, the project created increased predation rates. However, we species’ historic range, which indicates one stabilized, self-sustaining channel find no evidence to indicate that current that these species persist through from numerous small channels using levels of predation threaten the drought cycles. revetments and transverse dikes. In continued existence of either chub Our status review examined the 1986, Congress authorized mitigation for species. Sampling of chub habitats in impact of entrainment of sturgeon chubs fish and wildlife habitat losses recent years strongly suggests that these by irrigation structures and potential associated with the construction, short-lived species are reproducing in water quality impacts. We have entered operation, and maintenance of the BSNP adequate numbers to sustain viable formal consultation under section 7 of in Nebraska, Iowa, Kansas, and populations for the foreseeable future. the Act concerning impacts to pallid Missouri. The project mitigation plan 4. The inadequacy of existing sturgeon (Scaphirhynchus albus) authorized the acquisition of 29,900 regulatory mechanisms. associated with the Intake Diversion acres (12,109 hectares) and the Currently there is no Federal legal Structure and lowhead dam, and development of an additional 18,200 protection for the sicklefin and sturgeon Reclamation’s plans to privatize and acres (7,371 hectares) of existing public chubs. In addition, few States provide transfer the facilities to the Lower land. Recently, the mitigation plan was any legal protection to these species. Yellowstone Irrigation District. Studies reauthorized as part of the Water Within their historical range, both chubs conducted at this structure projected Resources Development Act of 1999, receive legal protection in the State of that over 2,000,000 fish were entrained and the acquisition ceiling was Kansas where the sturgeon chub and in the irrigation canal system during the increased by 118,650 acres (48,053 sicklefin chub are classified officially as 1996, 1997, and 1998 irrigation seasons. hectares). Based on the conceptual plans threatened and endangered, Reclamation estimated that over 289,000 that have been developed, State and respectively. Take of either species is ± 113,000 sturgeon chub were entrained Federal agencies anticipate the prohibited, and provisions allow for during the 3-year study period. rehabilitation of aquatic and terrestrial habitat protection and designation of Reclamation is working with the Service habitats will benefit fish and wildlife critical habitat (Kansas Department of and others to develop a design that resources, including the sicklefin and Wildlife and Parks 1992). In South allows for fish passage over the lowhead sturgeon chub. Dakota, both chubs officially are listed dam and minimizes entrainment losses. In November 2000, we completed a as State threatened. The State of Illinois Implementation of ‘‘fish friendly’’ biological opinion under Section 7 of prohibits the take of the sturgeon chub measures will benefit the sturgeon chub the Act on the Corps of Engineers’ and provides some habitat protection population in the Yellowstone River. Operation of the Missouri River Main (Sue Lauzon, pers. comm. 1995). Conservation measures developed for Stem System, the related operation of Kentucky has restrictions on collections the Intake Diversion Structure and the Kansas River Tributary Reservoirs, of both chubs (Wayne Davis, Kentucky lowhead dam may be applicable at other and the Operation and Maintenance of Department of Fish and Wildlife water diversion sites on the Yellowstone the Missouri River Bank Stabilization Resources, pers. comm. 1995), and River. and Navigation Projects (U.S. Fish and
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Wildlife Service 2000). We found that, greater numbers than previously 2000 Progress Report. Montana Department to avoid jeopardizing the continued believed. Researchers in Montana of Fish, Wildlife, and Parks. Lewistown. existence of the pallid sturgeon, least (Grisak 1996, Gardner 2000a, b), North Grady, J.M., and J. Milligan. 1998. Status of tern, and piping plover, conservation Dakota (Liebelt, in litt. 1999, Everett selected cyprinid species at historic Lower measures to restore riverine and aquatic Missouri River sampling sites. U.S. Fish and 1999, Welker 2000), and Missouri Wildlife Service, Columbia, Missouri. 49 pp. habitat and hydrologic conditions on (Grady and Milligan 1998, Hrabik and Grisak, G.G. 1996. The status and segments of the Missouri River between Herzog, in litt. 2000a, b) have collected distribution of the sicklefin chub in the Fort Peck Dam and the headwaters of substantially greater numbers of Middle Missouri River, Montana. M.S. Lake Sakakawea and below Gavins sicklefin and sturgeon chub using Thesis, Montana State University, Bozeman. Point Dam are necessary. The emphasis trawling techniques. Recently, new 77 pp. of the Biological Opinion is to restore or locations supporting sicklefin and Hrabik, R., and D. Herzog, in litt. 2000a. rehabilitate enough of the Missouri sturgeon chub populations, such as the Missouri Department of Conservation, Open River ecosystem to avoid jeopardizing Wolf Island area of the Lower River Field Station, Jackson. Hrabik, R., and D. Herzog, in litt. 2000b. the pallid sturgeon and other listed Mississippi River, have also been species. Implementation of the Missouri Department of Conservation, Open identified. River Field Station, Jackson. identified conservation measures are While major information gaps remain Liebelt, J., in litt. 1999. Fisheries Biologist, expected to have a significant beneficial concerning feeding habits, reproduction, Montana Department of Fish, Wildlife and effect on sicklefin and sturgeon chub seasonal habitat use, and other aspects Parks, Fort Peck. through habitat restoration and creation of sicklefin and sturgeon chub biology, U.S. Fish and Wildlife Service. 1993a. projects, improved water temperature substantially greater emphasis has been Status report on sicklefin chub regimes, and flow modifications (Macrhybopsis meeki), a candidate placed on documenting chub endangered species. U.S. Fish and Wildlife designed to mimic the natural populations and their habitats during hydrograph. The Corps of Engineers is Service, Bismarck, North Dakota. 41 pp. the past 7 years. Therefore, on the basis U.S. Fish and Wildlife Service. 1993b. currently seeking public input on the of the best available information, we Implementation Plan for the Reasonable Status report on sturgeon chub conclude that neither the sicklefin chub (Macrhybopsis gelida), a candidate and Prudent Alternative identified in nor the sturgeon chub is likely to endangered species. U.S. Fish and Wildlife the Biological Opinion. become threatened or endangered in the Service, Bismarck, North Dakota. 58 pp. Conclusions foreseeable future throughout all or a U.S. Fish and Wildlife Service. 2000. significant portion of their range. Missouri River Biological Opinion. Denver, The principal factors impacting Colorado and Fort Snelling, Minnesota. 286 sicklefin and sturgeon chub populations Therefore, listing either the sicklefin pp. are the construction and continuing chub or the sturgeon chub is not U.S. Fish and Wildlife Service. 2001. operation of the dams on the main stem warranted at this time. Updated status review of sicklefin and Missouri River and channelization of This finding is based on our analysis sturgeon in the United States. USFWS the Middle and Lower Missouri and of the current status and potential Denver, Colorado 74 pp. Mississippi Rivers. Water depletion threats to these two cyprinids. In Welker, T.L. 2000. Ecology and structure of addition we are encouraged by proposed fish communities in the Missouri and Lower projects, impoundments, entrainment, Yellowstone Rivers. PhD. Thesis, University and drought have impacted sturgeon modifications in the operation of the of Idaho, Moscow. 232 pp. chub populations in the Yellowstone Federal projects on the main stem River and tributaries to the Yellowstone Missouri River, which when fully Author and Missouri Rivers. The threats posed implemented will improve native fish The primary author of this document by the dams and reservoirs have been in habitat and benefit sicklefin and is William Bicknell (see ADDRESSES place for over 35 years. Despite the loss sturgeon chub populations. above). of over 1,000 miles of suitable habitat in References Cited the Missouri River, viable, self- Authority sustaining populations of sicklefin and Everett, S.R. 1999. Life history and ecology The authority for this action is the of three native benthic fishes in the Missouri sturgeon chubs occur where habitat Endangered Species Act of 1973, as conditions, flow patterns, and turbidity and Yellowstone Rivers. M.S. Thesis. University of Idaho, Moscow. amended (16 U.S.C. 1531 et seq.). levels resemble conditions prior to the Gardner, W.M. 2000a. Upper Missouri Dated: April 10, 2001. construction of the main stem dams. River Pallid Sturgeon Recovery Studies— Marshall P. Jones, Jr., Field studies conducted since the 1999 Progress Report. Montana Department 1993 status reports were issued indicate of Fish, Wildlife, and Parks. Lewistown. Acting Director, Fish and Wildlife Service. that sicklefin chub and sturgeon chub Gardner, W.M. 2000b. Upper Missouri [FR Doc. 01–9443 Filed 4–17–01; 8:45 am] are more widespread and occur in River Pallid Sturgeon Recovery Studies— BILLING CODE 4310–55–P
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