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Sturgeon Outlive T-Rex, But Not Us?

A little-known fish that has swum the darkest depths of our rivers since dinosaurs tramped the Earth surfaced in the spotlight this June when three environmental groups petitioned National Marine Fisheries Service to list it under the Endangered Species Act. According to Cynthia Elkins with the Environmental Protection Information Center (which filed the suit along with WaterKeeper and the Center for Biological Diversity), the fact that the green sturgeon outlived the dinosaurs-but now faces extinction-is cause for alarm.

This deep green fish, with its armored back, shovel-shaped snout, vacuum-like suction device (beneath its chin), and two sets of feelers that help it find food, is in serious trouble. Dams, diversion structures, and sediment pollution have altered the habitat and hydrology of the freshwater rivers in which the fish once spawned, leaving only a few fish in the Klamath, Trinity and Sacramento Rivers. They once spawned in the Eel and San Joaquin Rivers, too, but no longer. A recent study by the American Fisheries Society concluded that the sturgeon has declined by more than 88 percent in most of its historical range, which once stretched along the West Coast from Mexico to Alaska.

But some experts are not yet convinced the fish needs to be listed. Green sturgeon have always been more scarce than the commercially preferred white sturgeon (tagging studies result in an average catch of one green to every 100 white sturgeon), but it is not obvious that the population in the Estuary is declining, says Cal Fish & Game biologist Dave Kolhorst. "They may even be doing better than in the past because of the raising of the Red Bluff diversion dam gates from the winter months through May 15, which leaves more water in the river for fish," he says.

If green sturgeon are anything like white sturgeon, he adds, they have benefited from the recent wet winters. Kolhorst says that in sampling for young salmon, he also finds young sturgeon.

But environmentalists say that finding young sturgeon does not lessen the need for immediate action on the species' behalf. "We've seen the decline of large adults in our rivers," says Jeff Miller with the Center for Biological Diversity. According to Miller, the size of the fish being caught has decreased, which may mean that the prime breeding fish have been lost. The sturgeon is long-lived (up to 70 years) but doesn't spawn until it is sometimes as old as 20, and even then not always very successfully. Delayed reproduction, combined with habitat destruction and pressure from fishing, makes it difficult for the sturgeon to replenish their populations quickly. "Fish-catch numbers have plummeted," says Miller. "And more spawning populations have been lost than still exist."

One thing that enviros and agency folks agree on is that this odd primeval fish needs to be better studied. To that end, the U.S. Fish & Wildlife will soon launch a study. National Marine Fisheries Service has until early September to make a preliminary recommendation on the petition for listing, and a year to make a final determination.
Contact: Jeff Miller: (510) 841-0812, ext.3; Dave Kolhorst: (209) 948-7080 LOV

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