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“The 700 fishes now listed represent a staggering 92 percent increase
over the 364 listed as ‘imperiled’ in the previous 1989 study
published by the American Fisheries Society”
“‘Human populations have greatly expanded in many of these
watersheds, compounding negative impacts on aquatic ecosystems,’
noted Howard Jelks, a USGS researcher and the senior author of the
paper.
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US Geological Survey
News Release
http://www.usgs.gov/newsroom/article.asp?ID=2019&from=rss_home
Silent Streams? Escalating Endangerment for North American Freshwater
Fish: Nearly 40 Percent Now At-Risk
Nearly 40 percent of fish species in North American streams, rivers
and lakes are now in jeopardy, according to the most detailed
evaluation of the conservation status of freshwater fishes in the
last 20 years.
The 700 fishes now listed represent a staggering 92 percent increase
over the 364 listed as “imperiled” in the previous 1989 study
published by the American Fisheries Society. Researchers classified
each of the 700 fishes listed as either vulnerable (230), threatened
(190), or endangered (280). In addition, 61 fishes are presumed
extinct.
The new report, published in Fisheries, was conducted by a U.S.
Geological Survey-led team of scientists from the United States,
Canada and Mexico, who examined the status of continental freshwater
and diadromous (those that migrate between rivers and oceans) fish.
“Freshwater fish have continued to decline since the late 1970s, with
the primary causes being habitat loss, dwindling range and
introduction of non-native species,” said Mark Myers, director of the
USGS. “In addition, climate change may further affect these fish.”
Most Vulnerable Groups
The groups of fish most at risk are the highly valuable salmon and
trout of the Pacific Coast and western mountain regions; minnows,
suckers and catfishes throughout the continent; darters in the
Southeastern United States; and pupfish, livebearers, and goodeids, a
large, native fish family in Mexico and the Southwestern United
States.
Nearly half of the carp and minnow family and the Percidae (family of
darters, perches and their relatives) are in jeopardy. Fish families
important for sport or commercial fisheries also had many populations
at risk. More than 60 percent of the salmon and trout had at least
one population or subspecies in trouble, while 22 percent of
sunfishes – which includes the well-known species such as black bass,
bluegill and rock bass – were listed. Even one of the most popular
game species in the United States, striped bass, has populations on
the list.
Regions with the Most Troubled Fish
Regions with especially notable numbers of troubled fish include the
Southeastern United States, the mid-Pacific coast, the lower Rio
Grande and basins in Mexico that do not drain to the sea.
Hotspots of regional biodiversity and greatest levels of endangerment
are the Tennessee (58 fishes), Mobile (57), and the southeastern
Atlantic Slope river systems (34). The Pacific central valley,
western Great Basin, Rio Grande and rivers of central Mexico also
have high diversity and numbers of fish in peril, according to the
report. Many of the troubled fish are restricted to only a single
drainage. “Human populations have greatly expanded in many of these
watersheds, compounding negative impacts on aquatic ecosystems,”
noted Howard Jelks, a USGS researcher and the senior author of the
paper.
Degree of Trouble
Of fish on the 1989 imperiled list, 89 percent are either still
listed with the same conservation status or have become even more at
risk. Only 11 percent improved in status or were delisted. The
authors emphasized that improved public awareness and proactive
management strategies are needed to protect and recover these aquatic
treasures.
“Fish are not the only aquatic organisms undergoing precipitous
declines,” said USGS researcher Noel Burkhead, a lead author on the
report and the chair of the AFS Endangered Species Committee.
“Freshwater crayfishes, snails and mussels are exhibiting similar or
even greater levels of decline and extinction.”
The authors noted that the list was based on the best biological
information available. “We believe this report will provide national
and international resource managers, scientists and the conservation
community with reliable information to establish conservation,
management and recovery priorities,” said Stephen Walsh, another lead
author and USGS researcher.
This is the third compilation of imperiled, freshwater and diadromous
fishes of North America prepared by the American Fisheries Society’s
Endangered Species Committee. Additional information is available at
http://fisc.er.usgs.gov/afs/
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