Silent streams? Escalating endangerment for North American freshwater fish

Sep 09, 2008

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.

Source: United States Geological Survey

Explore further: Microplastics in the ocean: Biologists study effects on marine animals

add to favorites email to friend print save as pdf

Related Stories

World's oldest penguin undergoes cancer radiation

Dec 12, 2014

A toddler on Tuesday peered through thick glass as Tess – the world's oldest African penguin, representing an endangered species set to vanish in the child's lifetime – dove into her pool at the Pueblo Zoo. It was the ...

Pacific states say tuna talks making slow progress

Dec 03, 2014

Pacific island states expressed frustration Wednesday at a lack of progress in talks aimed at protecting the region's valuable tuna resources, accusing powerful faraway fishing nations of stalling on conservation ...

Iberian orcas, increasingly trapped

Dec 01, 2014

Thanks to the more than 11,200 sightings of cetaceans over the course of ten years, Spanish and Portuguese researchers have been able to identify, in detail, the presence of orcas in the Gulf of Cadiz, the ...

How can we avoid kelp beds turning into barren grounds?

Nov 28, 2014

Urchins are marine invertebrates that mould the biological richness of marine grounds. However, an excessive proliferation of urchins may also have severe ecological consequences on marine grounds as they ...

Recommended for you

New challenges for ocean acidification research

1 hour ago

Over the past decade, ocean acidification has received growing recognition not only in the scientific area. Decision-makers, stakeholders, and the general public are becoming increasingly aware of "the other carbon dioxide ...

Compromises lead to climate change deal

2 hours ago

Earlier this month, delegates from the various states that make up the UN met in Lima, Peru, to agree on a framework for the Climate Change Conference that is scheduled to take place in Paris next year. For ...

Finding innovative solutions for reducing CO2 emissions

4 hours ago

Today, the company Gaznat SA and EPFL signed an agreement for the creation of two new research chairs. The first one will study ways to seize carbon dioxide (CO2) at its production source and increase its value ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

manojendu
3 / 5 (4) Sep 10, 2008
Its strange!! Nobody to dispute this piece of news and counter that the environmental degradation doesn't exist!
wawadave
3 / 5 (4) Sep 10, 2008
We will soon follow them into extinction.
ofidiofile
not rated yet Sep 12, 2008
Its strange!! Nobody to dispute this piece of news and counter that the environmental degradation doesn't exist!


read the paper. present counter-evidence. that's how it works.

but disputing a scientific study simply because you don't like its conclusions is no argument at all.
jeffsaunders
not rated yet Oct 15, 2008
Its strange!! Nobody to dispute this piece of news and counter that the environmental degradation doesn't exist!


What's to dispute?

It seems pretty reasonable a strait forward to me. One would have to say it is inevitable. How can all these species survive when all their habitat is being destroyed?

Fish have some difficulty living out of water.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.