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<br />272
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<br />
<br />FISH CULTURE IN FISHERIES MANAGEMENT
<br />
<br />Species Preservation Act. This legislation and its
<br />successor, the Endangered Species Conservation
<br />Act of 1969, directed the Department of Interior
<br />to identify those species facing extinction because
<br />of human influence. The ESA of 1973 significantly
<br />increased Federal involvement with endangered
<br />species by, (1) protectihg the habitats upon which
<br />endangered species depend, (2) preventing federal
<br />actions frqm further jeopardizing listed species,
<br />(3) prohibiting the taking of listed species, and
<br />(4) providing for the recovery of listed species
<br />through direct federal actions and, indirectly,
<br />through grants-in-aid to participating states. The
<br />U.S. Fish and Wildlife Service (FWS) was charged
<br />with implementation of these goals.
<br />Dexter NFH was constructed by the FWS in
<br />the mid-1930s as a warm-water hatchery to supply
<br />largemouth bass (Micropterus salmoides) and
<br />channel catfish (Ictalurus punctatus) for New Mex-
<br />ico. It served this function for 40 years, until
<br />centralization moved the federal warm-water fish
<br />rearing program to hatcheries in Texas. Dexter
<br />was offered to the state of New Mexico, which
<br />declined it. Subsequently, its potential as a rearing
<br />and research center for endangered fish species
<br />was considered.
<br />The first question that the FWS addressed was
<br />whether an endangered-fishes rearing center was
<br />even needed. The ESA of 1973 charged the De-
<br />partment of Interior with listing, protecting, and
<br />recovering those species determined to be nearing
<br />extinction. Certainly, many of the southwestern
<br />fish species meet that criterion, as 81 % of the
<br />native Arizona fish fauna are presently classified
<br />or proposed as threatened or endangered by state
<br />or federal agencies, and 42% of New Mexico's
<br />species are similarly classified (Johnson and Rinne
<br />1982). California, Nevada, and Texas native desert
<br />fishes are in no better shape. In all, the FWS
<br />estimates that more than 35 species of south-
<br />western fishes presently may be in need of some
<br />type of artificial' propagation in order to survive.
<br />A survey of southwestern political and academic
<br />institutions was taken in 1974 to determine support
<br />for an endangered-fishes rearing facility like Dex-
<br />ter NFH. Support was'overwhelming, prompting
<br />a decision to begin moving non-game fish species
<br />into the facility. The first six native southwestern
<br />fish species came into Dexter in November, 1974.
<br />Early in the planning process for Dexter NFH,
<br />criteria were developed to determine site suita-
<br />bility, including many of the standard needs of .
<br />fish hatcheries-location, water quality and quan-
<br />.tity, space, access, security, and climate. Two of
<br />
<br />the principal criteria for locating an endangered
<br />fishes facility are unique, and worthy of special
<br />notice. First, isolation of the facility from natural
<br />surface waters is essential. Wild fish from many
<br />different drainages may come into the facility, and
<br />escapement of the fish, or their parasites or disease
<br />organisms, could create problems for local wild
<br />fish populations. Secondly, it is essential to isolate
<br />culture ponds from one another, because many
<br />of the fish species involved are phylogenetically
<br />similar and could produce fertile hybrids. Should
<br />hybridization occur, it would be nearly impossible
<br />to distinguish parental phenotypes from hybrids.
<br />Dexter NFH is suitably "land locked" and meets
<br />the first requirement, but isolation of more than
<br />a dozen species (see Table 1) in adjoining ponds
<br />fosters continuing concern in spite of detailed
<br />procedures (see following) that have been devel-
<br />oped to minimize chahce mixing of stocks. . <
<br />The goals for an endangered fishes rearing
<br />center were derived from the recovery needs for
<br />all species in question. More than 20 recovery
<br />plans have been completed for southwestern fishes,
<br />to date, and nearly all have several similarg?als
<br />that pertain to artificial propagation, viz~~" ;'\'
<br />1. A refuge should be established to protect
<br />the genetic stock if a catastrophe \y~re. to
<br />eliminate the species from the wild."; i ;'::'
<br />2. Research should be initiated JO detcnniqe
<br />. ,", I _: ,_ i'" ~. ~ ,'"
<br />specific needs of each species.
<br />3. A stocking program should be developed to
<br />re-introduce locally extirpated populations
<br />.,'. t
<br />into historic habitats. . ., "'<:
<br />The first two goals have inherent problems of
<br />scientific interest (e.g., how do you maintain
<br />populations of up to 35 species of fish that have
<br />never before been reared in artificial habitats?).
<br />The third goal is the most politically orieqted, and
<br />in need of further discussion: "', \ < ,I '
<br />I . .
<br />Re-introduction is a political issue because it
<br />involves restocking listed species into historic hab-
<br />itats, and initiating protective portions of the ESA
<br />that land managing agencies must consider in the,r. .
<br />plans and activities (Johnson 1979). Apprehension
<br />centers around the potential curtailment of on-
<br />going or planned programs in reintroduction areas
<br />in order to provide protection for the listed species.
<br />Specific worries included prevention of fishing,
<br />boating, minnow seining, swimming, domestic
<br />livestock grazing, irrigating, even energy devel~
<br />opment. The result of these untested apprehen-
<br />sions was that none of the fishes that were. being
<br />produced at Dexter NFH was being re-introduced
<br />into the wild. For several species, the numbers
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