Of the 1,676 species on the Lists of Endangered and Threatened Wildlife
and Plants (as of November 30, 1997), seven have been delisted due to extinction.
of these species -- the Tecopa pupfish, longjaw cisco, blue pike, and Santa Barbara song sparrow -- were protected under laws pre-dating the ESA, and therefore
were automatically listed under the ESA when it passed in 1973. They were apparently already extinct by 1973, however.
Tecopa pupfish. The Tecopa pupfish (Cyprinodon nevaensis)
was first described in 1948 from the outflow streams of the north and south
Tecopa Hot Springs,
north of Tecopa, California. In 1970, the declining Tecopa pupfish population was listed on both the federal and California endangered species lists due to habitat
alteration and introductions of exotic species, primarily bluegill sunfish and mosquito fish. By 1972, the species no longer occurred where the species was first found.
Surveys done in 1977 failed to locate any other populations. In 1982, the FWS determined the Tecopa pupflsh was extinct and removed it from the endangered
species list (47 FR 2317).
Longjaw cisco. The longjaw cisco (Coregonus alpenae) was
one of several species of deepwater whitefish that was an important part
of the smoked fish industry
in the Great Lakes. It was known to occur in Lakes Michigan, Huron, and Erie. Extensive over-fishing and increased lake pollution led to a population crash in the
first half of the 20th Century. The cisco was further decimated by sea lamprey predation and habitat degradation, and has not been seen in Lakes Huron and Erie
since the 1950's. The last collection in Lake Michigan was in 1967, at which time the species was listed as endangered under the ESPA. In 1983, the FWS declared
the longjaw cisco extinct and took it off the endangered species list (48 FR 39942).
Blue pike. The blue pike (Stizostedion vitreum glaucum)
was abundant in the commercial fishery of the Great Lakes. It was historically
found in Lakes Erie and
Ontario, and in the Niagara River. ~ 1915, population levels began a cycle of extreme fluctuation caused by over-fishing, leading to the eventual collapse in 1958.
The FWS listed the pike as endangered under the ESCA in 1970. suggesting that introgressive hybridization with walleye may have caused the final disappearance of
the stock. A survey by the Blue Pike Recovery Team in 1977 found no individuals. In 1983, the EWS declared the blue pike extinct and removed it from the
endangered species list (48 FR 39942).
Santa Barbara song sparrow. The Santa Barbara song sparrow
(Melospiza melodia graminea) is a subspecies of the song sparrow that was
known to exist only
on Santa Barbara Island, Los Angeles County, California. No Santa Barbara song sparrows have been seen since a fire in 1959 destroyed most of the 640-acre
island's habitat. In 1983, the FWS determined that M.m.graminea was extinct and removed it from the endangered species list (48 FR 46336).
Sampson's pearly mussel. Sampson's pearly mussel (Epioblasma
(=Dysnomia) sampsoni) is a freshwater bivalve mollusk that was historically
found in parts of
the Wabash River in Illinois and Indiana, and parts of the Ohio River near Cincinnati. Dam construction and siltation eliminated much of the gravel and sandbar
habitat where the species was found. The FWS listed this mussel as endangered under the ESA in 1976 (41 FR 24064). A status review initiated in 1981
determined that "no specimens had been collected in over 50 years, despite repeated sampling within its range." In 1984, the FWS concluded that Sampson's pearly
mussel was extinct and removed it from the endangered species list (49 FR OS 7).
Amistad gambusia. The Amistad gambusia (Gambusia amistadensis)
was a small fish known only to occur in Goodenough Spring, Val Verde County,
tributary of the Rio Grande River. This species was eliminated in the wild when construction of the Amistad Reservoir in 1968 submerged Goodenough Spring under
approximately 70 feet of water. The FWS listed the Amistad gambusia as endangered in 1980, at which time it occurred only in captivity (45 FR 28721). The two
captive populations, held by the University of Texas and the Dexter National Fish Hatchery in New Mexico, died or were eliminated through hybridization and
predation. The FWS ruled the Amistad gambusia extinct in 1987, and removed it from the endangered species list (52 FR 46083).
Dusky seaside sparrow. The dusky seaside sparrow subspecies
(Ammodramus maritimus nigrescens) was a small songbird that existed only
on Merritt Island
and the upper St. Johns River marshes of Brevard County, Florida. Populations of the sparrow declined as its salt marsh habitat was converted to freshwater
mosquito-control impoundments, or drained. The use of DDT to control mosquitos was also suspected as a contributing factor in the species' decline.
Dusky seaside sparrows were first listed as endangered in 1967 under
the ESPA (32 FR 4001). The last remaining wild birds, all males, were taken
into captivity in
1979 and 1980 to begin a captive breeding program. The males were mated with females of a closely related subspecies (Scott's seaside sparrow, A. m.
peninsulae) to try to preserve their genetic information. The hybrid offspring were not protected under the ESA and the breeding program proved unsuccessfiil. The
last male sparrow died on June 16, 1987, and the hybrid offspring died by the summer of 1989. In 1990, the FWS declared the dusky seaside sparrow extinct and
took it off the endangered species list (55 FR 51112).
From: Congressional Research Service Report for Congress Endangered Species List Revisions: A Summary of Delisting and Downlisting, Robert J. Noecker,
THE COMMITTEE FOR THE NATIONAL INSTITUTE
FOR THE ENVIRONMENT.1998
Woodrow Wilson National Fellowship Foundation
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