The Biggest Fish in the Pond
Sturgeon can live decades and grow to be North America’s largest freshwater fish, but challenges to their survival have endangered five of the continent’s eight species
- Roger Di Silvestro
- Feb 01, 2005
FOR A FISH that once provided food for dinosaurs and other ancient predators, the sturgeon has shown amazing resilience. It has outlasted not only the sea-going ichthyosaurs but even the rivers in which its ancestors spawned. Indeed, whole continents have shifted and convulsed since sturgeon first appeared in North America’s fossil record at least 100 million years ago.
Twenty-four sturgeon species survive worldwide today, including the largest freshwater fish species in the world, the beluga of the Caspian and Black Seas and the Volga River, which can weigh up to 3,000 pounds. How long sturgeon will continue to survive is, however, anyone’s guess, as these fish face a plague of modern threats.
North American rivers, lakes and coast waters are home to eight sturgeon species. The white sturgeon, which lives along the Pacific coast from Alaska to Monterey, California, grows largest. One unofficial report from British Columbia in 1897 boasts of a female that weighed nearly 1,800 pounds. In 1912, a 1,300-pound female was caught in Washington. Sturgeon of that weight can measure 20 feet long, and they live long, too—up to 150 years for some species.
However, because of threats ranging from pollution to fishing pressure to loss of spawning areas as dams cut off rivers, sturgeon rarely live long enough today to grow that large. “Due to multiple causes, the probability of a fish reaching that size is pretty small,” says Stephen Ross, curator of fishes at the University of Southern Mississippi and an expert on Gulf sturgeon.
Adult sturgeon are bottom feeders, using four barbels under their heads to probe for small fish, snails, clams, crabs, lancelets, shrimp and other mollusks and crustaceans, which they suck into toothless jaws. They begin life as eggs laid in streams in spring. The eggs hatch in about two weeks, and larval sturgeon feed on algae and small insects.
Juveniles of some species, such as the Atlantic sturgeon and Gulf sturgeon, make their way to coastal waters, where they mature for at least 12 years before returning to natal rivers to spawn. Females probably breed no more often than every three years. Late maturity is a factor in the sturgeon decline. “They can really be hammered by fishing in a few years, because they reach a legally harvestable size before they have a chance to breed,” Ross says.
Once common in American waters, sturgeon were regarded as trash fish until the mid-1800s, used only for fertilizer. By the late 19th century, however, the fish had caught on as a source of meat, leather and caviar.
Demand for sturgeon products helped put the fish into a steep decline. For example, in 1885, Great Lakes waters bordering Michigan accounted for a catch of 1.5 million pounds of sturgeon. By 1928, the catch in the area was less than 2,000 pounds. The commercial catch of white sturgeon peaked in the Columbia River in 1892 at more than 5 million pounds. During the early 1900s, the catch was scarcely 200,000 pounds.
Today, the lake, Gulf, pallid, Alabama and shortnosed species are listed as endangered or threatened by the U.S. Fish and Wildlife Service, and the green sturgeon is being considered for listing. The white and shovelnose are still fished for sport. Sturgeon may have survived the Age of Reptiles and the ice ages, but they may not survive the excesses of humankind.
Roger Di Silvestro is a senior editor of this magazine.
