federal `Aegister / Vol. 52, No. 233 / Friday, December 4. 1987 / Rules and Regulations 46083

DEPARTMENT OF THE INTERIOR

— and Wildlife Servic

50 CFR part-17

ndangered and Threatened Wildlife and Plants; Removal of amistadensis, the Amistad Gambusia, From the List of Endangered and Threatened Wildlife AGENCY: Fish and Wildlife_Servite. Interior._ - - --- ACTION: Final rule.

SUMMARY: The U.S. Fish and Wildlife Service is removing the Arni tad gambusia (Gambusia ami - .^4n7sis) from the List of EndangE -ec an.. Threatened Wildlife. This action is based on a review of all available data. which indicate that this fish is extinct. The species is known to have occurred naturally only in Goodenough Spring. Val Verde County, Texas. It was eliminated there by inundation from the Amistad Reservoir. an impoundment constructed on the Rio Grande River in 46084 Federal Register / Vol. 52. No. 233 / Friday, December 4, 1987 / Rules and Regulations

1968. All other springs considered likely Gambusia amistadensis was listed as Regulations at 50 CFR 424.11 state to harbor the species have been endangered on April 30, 1980 (45 FR that a species may be delisted if: (1) It examined, but it was never found. 28721), under provisions of the becomes extinct, (2) it recovers, or (3) Captive populations of G. amistadensis Endangered Species Act of 1973, as the original classification data were in were maintained, but have since died or amended, at which time it occurred only error. The Service believes that enough been eliminated through hybridizations in captivity at the University of Texas evidence exists to recognize Gambusia with and predation by the and Dexter National Fish Hatchery in amistadensis as extinct. The (Gambusia affinis). Removing the New Mexico. Since that time, all captive Endangered Species Act requires that Amistad gambusia from the List populations have died or been certain factors be considered before a constitutes Service recognition of its eliminated through hybridization with species can be listed, reclassified, or and removes Federal and predation by the mosquitofish, delisted. These factors and their protection under the Endangered Gambusia affinis. In the Federal application to G. amistadensis are as Species Act. Register of March 11, 1987 (52 FR 7462- follows: 7463), the Service published a proposed DATE: This rule becomes effective on The present or threatened rule to delist the Amistad gambusia. A. January 4, 1988. destruction, modification or curtailment ADDRESSES: The complete file for this Summary of Comments and of its habitat or range. The Amistad rule is available for inspection, by Recommendations gambusia was known to occur only in appointment, during normal business In the March 11, 1987, proposed rule Goodenough Spring, tributary to the Rio hours at the Service's Regional Office of (52 FR 7462) and associated Grande in Val Verde County, Texas. In Endangered Species, 500 Gold Avenue notifications, all interested parties were July of 1968, backwaters of the Amistad SW.. Room 4000, Albuquerque, New requested to submit information that Reservoir began permanent flooding of might contribute to the development of a the area. The Amsted gambusia is FOR FURTHER INFORMATION CONTACT: final rule. Appropriate State agencies. believed to have been extirpated in that Gerald L. Burton, Endangered Species county governments, Federal agencies, area. Biologist. U.S. Fish and Wildlife Service, scientific organizations, and other B. Overutilization for commercial, P.O. Box 1306, Albuquerque. New interested parties were contacted and recreational, scientific, or educational Mexico 87103 (505/766-3972 or FTS 474- requested to comment. A newspaper 3972). purposes. Not applicable. notice that invited general public C. Disease or predation. Not SUPPLEMENTARY INFORMATION: comment was published in the Del Rio applicable. News-Herald on April 3, 1987. Five Background comments were received and are D. The inadequacy of existing The Amistad (Goodenough) gambusia discussed below. regulatory mechanisms. Not applicable. (Gambusia amistadensis) is known to Comments of support were received E. Other natural or manmade factors have occurred only in Goodenough from the Texas Parks and Wildlife affecting its continued existence. All Spring, a tributary of the Rio Grande in Department, the American Society of captive populations of G. amistadensis Val Verde County, Texas. It was Ichthyologists and Herpetologists, a have died or been eliminated due to described by Dr. Alex Peden in 1973. faculty member from the University of hybridization with and predation by the based on specimens collected in 1968 Texas at Austin, and a faculty member mosquitofish (Gambusia affinis). from Goodenough Spring just prior to its from Pan American University. A letter inundation by Amistad Reservoir. The of opposition was received from a Effects of Rule species was not recognized as distinct faculty member from the University of until well after reservoir construction Oklahoma. This action removes this species from began (Peden 1973). During extensive The commenter from the University of the List of Endangered and Threatened collecting by Peden (1973) in spring Oklahoma stated that he could see no Wildlife. Federal agencies are no longer areas immediately upstream and benefit to delisting because of presumed required to consult with the Secretary to downstream from the Amistad extinction, and if the species remains on insure that any action authorized, Reservoir. no additional G. amistadensis the list, it will automatically have funded, or carried out by such agency is were found, and Peden believed that the protection if any other populations are not likely to jeopardize the continued species was restricted to the discovered. The Service responds that existence of the Amistad gambusia. Goodenough Spring area. maintaining a species on the List when it Federal restrictions on taking this In July 1968, backwaters of the is presumed extinct causes an species no longer apply. There is no Amistad Reservoir, constructed by the unnecessary burden on Federal designated critical habitat for this U.S. Army Corps of Engineers, began Agencies when they evaluate projects in species. permanent flooding of the area. In the context of section 7 of the subsequent visits to the area after the Endangered Species Act. In addition, if National Environmental Policy Act reservoir had filled, the spring was the species is rediscovered, it can be found to be under more than 21.3 meters relisted expeditiously under emergency The Fish and Wildlife Service has (70 feet) of silt-laden water, and Peden provisions of the Act. determined that an Environmental (1973) believed that the species was kssessment, as defined under the probably extirpated there. In 1979, all Summary of Status Findings ^-thority of the National Environmental Texas springs listed by Brune (1981) as After a careful review of all availabl( Poky Act of 1969, need not be prepared being within 50 kilometers (31 miles) of data, the Service has determined that in connection with regulations adopted Goodenough Spring with outflow in Gambusia amistadensis is extinct and pursuant to section 4(a) of the excess of 10 liters per second (0.353 no longer requires protection pursuant to Endangered Species Act of 1973, as cubic feet per second) were surveyed. the Endangered Species Act of 1973, as amended. A notice outlining the but no G. amistadensis were found, and amended. If evidence to the contrary is Service's reasons for this determination the species is believed to be extinct presented later, listing may be was published in the Federal Register (Hubbs and Jensen 1984). reproposed. on October 25, 1983 (48 FR 49244). 52. Federal Register Vol. Nu. 233 / Friday, December 4. 1987 / Rules and Regulations 46085

References Cited. Brune. C. 1981. Spiangs pf Texas. I. Branch. Smith. lnc". Ft. Worth Texas. Hobbs. C. and B.L. Jensen. 1984. Extinction of Gumbusia amistadensis, an endangered . Copeia 198414529-530. eden. A.E. 1973. Virtual extinction of ,ambusia amistadensis n. sp.. a poeciliid fish from Texas. Copeia 1973(2):210-221. Primary Author The primary author of this final rule is Alisa M. Shull, Endangered Species Biologist. U.S. Fish and Wildlife Service. Albuquerque. New Mexico 87103 (505/ 766-3972 or FTS 474-3972). List of Subjects in 50 CFR Part 17 Endangered and threatened wildlife. Fish. Marine mammals, Plants (agriculture). Regulation Promulgation Accordingly, Part 17, Subchapter B of Chapter I. Title 50 of the Code of Federal Regulations, is amended as set forth below: PART 17—(AMENDED) 1. The authority citation for Part 17 continues to read as follows: Authority: Pub. L. 93-205.87 Stat. 884: Pub. L. 94-359.90 Stat. 911: Pub. L. 95-632.92 Stat. 3751: Pub. L 96-159.93 Stat. 1225: Pub. L 97- 304.96 Siat. 1411 (16 U.S.0 1531 et seq.): Pub. L. 99-625.100 Stat. 3500 (1986). unless otherwise noted. 7.11 (Amended :. Amend 17.11(h) by removing Amistad gambusia ( Gambusia- amistadensis) under " from the List of Endangered and Threatened Wildlife. Dated: October 22.1987. Susan Recce. Acting Assistant Secretary for Fish and Wildlife and Parks. (FR Doc. 87-27912 Filed 12-3-87; 3:45 am] BILLING CODE 4310-5544 r