Center for Biological Diversity
Protecting endangered species and wild
places of western North America
FOR IMMEDIATE RELEASE: JUNE 11, 2001
PROTECTED STATUS SOUGHT FOR PREHISTORIC FISH
Conservation Groups Petition To List the Green Sturgeon as Endangered
Three conservation organizations filed a formal petition today to list a dwindling fish species, the green sturgeon, as endangered under the federal Endangered Species Act. The Environmental Protection Information Center (EPIC), Center for Biological Diversity, and WaterKeepers Northern California submitted the formal petition to the National Marine Fisheries Service to add the North American green sturgeon (Acipenser medirostris) to the growing list of endangered migratory fish.
Green sturgeon first appeared more than 200 million years ago and are among the largest and longest living species found in freshwater. The American Fisheries Society, a prominent scientific organization, recently reviewed the risk of extinction for marine fish in North American waters and determined that the green sturgeon is endangered, with an 88% decline in most of its range. Dams, diversions, sediment pollution, and over-fishing caused this rapid decline over the last century, and spawning populations are only known to occur in three river systems today - the Sacramento River and Klamath-Trinity River basins in California, and the Rogue River in Oregon. It estimated that the three remaining spawning populations contain only a few hundred mature females.
"The green sturgeon is truly one of nature's wonders, remaining unchanged in its appearance since the age of the dinosaurs. The alarming decline of this primeval creature is a strong indicator of the health of our river and estuary systems. We must act now to protect the sturgeon and restore the deep pools and clean, free-flowing water to the rivers of the Pacific Northwest," Cynthia Elkins, Programs Director of EPIC, said.
The green sturgeon is an olive green, prehistoric-looking fish that can reach 7.5 feet in length, 350 pounds and 70 years in age. It has a shovel-like snout and vacuum cleaner-like mouth that it uses to siphon food. Sturgeons are modern relics of the ancient group of bony fishes, and have a skeleton that is mostly cartilage rather than bone and rows of bony plates for protection instead of scales. The species ranges from Mexico to Alaska in marine waters and feeds in estuaries and bays from Monterey Bay and San Francisco Bay to British Columbia. Green sturgeons spawn in the fresh water of only a few large rivers, all of which have diversions, dams and sediment problems that limit flow regimes and suitable spawning conditions for green sturgeon.
"The green sturgeon
is in serious trouble," said Jeff Miller of the Center for Biological
Diversity. Miller added, "we have lost more spawning populations
of this species than remain today. The large river systems have been degraded
to the point that they are ceasing to function on an ecosystem level.
Given this and current unsustainable fishing practices, the Pacific Northwest
could lose its second largest freshwater fish in the blink of an eye."
The San Francisco Bay population of green sturgeon has been estimated to fluctuate between 500 and 1000 adult fish in the last few decades. The size of the Klamath basin population is unknown, but is likely the largest spawning population. It is believed that the spawning population in the Eel River disappeared by the 1970s, although a few adult sturgeon have been found upstream in recent years.
"The dams, serious sediment pollution and diversion of up to 90% of the water in the Eel River have nearly eliminated the green sturgeon from the watershed. These recent sightings of the fish are a glimmer of hope that the green sturgeon can one day be restored to its native streams and roam the waters of the Wild and Scenic Eel River as it has for eons," Elkins stated.
In addition to habitat destruction, historic over-fishing was a major cause of decline of the green sturgeon, and present fisheries probably continue to deplete a stock of large, old fish that cannot renew itself at present harvest rates. Sturgeons are highly vulnerable to over-fishing because of the long time it takes them to reach breeding maturity, and their infrequent reproductive success. Their large size and sluggish nature make them easy to net and snag. Until recently, various West Coast fisheries were harvesting at least 6,000 to 11,000 green sturgeon per year. In recent years, the annual harvest has been estimated at 3,000 to 5,000 adult fish. More restrictive sturgeon size limit fishing regulations have been gradually implemented in California, Oregon, and Washington - mainly aimed to protect the larger and more common white sturgeon, but which allow many of the large breeding-age green sturgeon to be caught.
Eight species of sturgeon occur in North America, four of which (plus one population of the white sturgeon) are already listed as endangered or threatened: the Shortnose sturgeon, Gulf sturgeon, Pallid sturgeon, Alabama sturgeon, and the Kootenai River population of the white sturgeon.
The National Marine
Fisheries Service has 90 days to make a preliminary finding on the formal
petition to protect the green sturgeon under the federal Endangered Species
Act, and one year to make a final listing determination.