October 27, 2008

Lake Sturgeon Profile


The lake sturgeon, with its sleek shape and rows of bony plates on its sides, looks a bit like an armored torpedo. These freshwater giants have greenish-grey coloring and a pointed snout with two pairs of whiskerlike tactile organs that dangle near its mouth. These organs, called barbels, help it to locate bottom-dwelling prey, such as snails, clams, insect larvae, and fish eggs.

Lake sturgeons can be huge, topping six feet (two meters) long and weighing nearly 200 pounds (90 kilograms). They are also extremely long-lived. Males may live some 55 years, and females can reach 150.

Despite their name, lake sturgeons are also found in rivers, but they avoid salt water. These fish were once a major part of North America's Great Lakes, Hudson Bay, and Mississippi River ecosystems and occurred from Canada to Alabama. But intense fishing has exacted a heavy toll on their populations.

These fish were once killed as a nuisance bycatch because they damaged fishing gear. When their meat and eggs became prized, commercial fishermen targeted them. Between 1879 and 1900, the Great Lakes commercial sturgeon fishery brought in an average of 4 million pounds (1.8 metric tons) per year.

Such unsustainable catch rates were coupled with environmental challenges such as pollution and the construction of dams and other flood control measures. Sturgeons, which return each spring to spawn in the streams and rivers in which they were born, found tributaries blocked and spawning shoals destroyed by silt from agriculture and lumbering.
The 20th century saw drastic drops in sturgeon catches, increased regulations, and the closure of viable fisheries. Currently 19 of the 20 states within the fish's original U.S. range list it as either threatened or endangered.

In recent years, however, the great fish has made something of a comeback. Strong efforts at righting environmental wrongs in the Great Lakes have improved conditions, and concentrated efforts to protect the fish have turned sturgeon into a spotlight species.

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