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lq~~ WIIIIt41/lS .. -11 q t.J American Fisheries Society Guidelines for Introductions of Threatened and Endangered Fishes Jack E. Williams, Donald W. Sada, Cynthia Deacon Williams and Other Members of the Western Division Endangered Species Committee1 ABSTRACT Introductions of threatened and endangered fishes are often an integral feature in their recovery programs. More than 80% of threatened and endangered fishes have recovery plans that call for introductions to establish a new population or an educational exhibit, supplement an existing population, or begin artificial propagation. Despite a large number of recent and proposed introductions, no systematic procedural policies have been developed to conduct these recovery efforts. Some introductions have been inadequately planned or poorly implemented. As a result, introductions of some rare fishes have been successful, whereas recovery for others has progressed slowly. In at least one instance, the introduced"fish eliminated a population of another rare native organism. We present guidelines for introductions of endangered and threatened fishes that are intended to apply when an introduction is proposed to supplement an existing population or establish a new population. However, portions of the guidelines may be helpful in other situations, such as establishing a hatchery stock. The guidelines are divided into three components: (1) selecting the introduction site, (2) conducting the introduction, and (3) post-introduction monitoring, reporting, and analysis. Implementation should increase success of efforts to recover rare fishes. Readers are invited to comment on the following proposed guidelines which will be presented to the AFS Executive Committee for approval at their 1989 Spring meeting. Cor- respondence should be sent directly to the senior author, Jack E. Williams, Department of Wildlife and Fisheries Bi- ology, University of California, Davis, CA 95616-5270. "On 3 August 1968, we collected 30 or 40 individuals from among the inundated prickly pear and mesquite near the flooded spring, which by that time was covered with about 7 m of clear water."-Peden (1973) The above quote described the collection of Amistad gambusia, Gambusia amistadensis, as its habitat was being flooded. Fortunately, most translocations of endan- gered fishes do not occur under such a feverish pace as did this collection of Amistad gambusia. This gambusia was known only from Goodenough Spring, Texas, which was inundated by reservoir impoundment. The original stock of 30 to 40 individuals was taken to the Brackenridge Field Laboratory at Austin, Texas. In 1974, portions of the stock were transferred to Dexter National Fish Hatchery in New IJames R. Bennett, James E. Johnson, Paul C. Marsh, Don E. McAllister, E. Philip Pister, Randy D. Radant, John N. Rinne, Michael D. Stone, Linda Ulmer, and Donna L. With- ers. September - October 1988 Mexico for propagation. But in 1979, all stocks were exam- ined and found to consist solely of mosquito fish, Gambusia affinis, which had somehow contaminated the population during the preceding years (Hubbs and Jensen 1984). The species was extinct. Unlike the tragic scenario of the Amistad gambusia, most recovery programs for endangered or threatened fishes are conceived and executed under more favorable circumstan- ces. The Fish and Wildlife Service is required to develop recovery plans for those species listed as endangered or threatened pursuant to Section 4(f) of the Endangered Species Act of 1973. In recent years, introductions have become a prominent feature of most recovery programs for rare fishes. With the widespread use of introductions as a method to recover rare fishes, the need for standardized procedures has become clear. The purpose of this paper is to present a standardized procedure and encourage its use through acceptance by the American Fisheries Society. Also, we encourage documentation and analysis of introduction at- tempts so that future efforts will have greater opportunity to benefit from these experiences. Background Results of introductions of endangered and threatened fishes are seldom reported in the literature. Even less frequently are introductions analyzed to determine causes of successes or failures. Three noteworthy exceptions exist. Hoover and St. Amant (1983) reported that only two of 12 introductions of the endangered Mohave tui chub, Gila bicolor mohavensis, led to established populations. Johnson 5