A COMMON PROPERTY PROBLEM. The Black and Caspian Sea fisheries have not been well-managed, and Wabash caviar is replacing Beluga at the receptions of the well-to-do.

Every spring, fishermen wait for a peculiar-looking fish to swim up the Wabash River between southern Illinois and Indiana.

The shovelnose sturgeon, a prehistoric survivor covered with bony plates and wearing a strip of barbs down its back, is plentiful in the river and lives up to 60 years.

Scientists worry that the decline of another type of sturgeon could mean trouble for the shovelnose, North America's smallest sturgeon.

The shovelnose and its eggs have become increasingly popular in the caviar trade because the beluga sturgeon, which produces the most popular caviar, has declined because of overfishing in the Black and Caspian seas. The United States and other countries restrict or ban the import of beluga caviar. Now states are beginning to look for ways to protect the shovelnose.

The shovelnose appears to be a different sturgeon from the Great Lakes sturgeon, also a source of North American caviar. In Wisconsin's Lake Winnebago, the fish can only be taken with a spear.

Because the fish are late maturing, any decline in the population of adult fish could take decades to rebuild, said Fred P. Binkowski, a senior scientist at the Great Lakes Water Institute at the University of Wisconsin-Milwaukee who raises sturgeon in his lab and is beginning to stock them in rivers feeding Winnebago.

Some people are working to reintroduce them to other Wisconsin waters. The effort takes on greater urgency with the discovery of viral hemorrhagic septicemia virus in Lake Winnebago.

Scientists figured it was only a matter of time before the fish virus moved from Huron and Erie to Lake Michigan, but to suddenly jump to one of Wisconsin's most heavily fished inland lakes is a surprise. Though in some respects, it's not a shock, since hardcore walleye anglers will sometimes fish the western basin of Lake Erie before pulling their boat trailers to the Winnebago system.

(Hail, hail to Michigan, the cesspool of the west?)

The effect on Winnebago's lake sturgeon, the largest population in North America with an estimated 36,000 to 37,000 adults, is unknown. For the first time, sturgeon speared in February during the annual harvest were tested for [the virus] because of concern about the virus moving through the Great Lakes, said Ron Bruch, [Wisconsin's Department of Natural Resources'] sturgeon expert.

The tests came back negative, but Bruch said that because the virus is most active when water temperatures are between 40 and 60 degrees, he wonders if the 33-degree water temperature during the February sturgeon season could have affected test results.

"That's what I have to find out - would it even show up in a wintertime testing?" he said.

Bruch plans to contact fisheries biologists who monitor lake sturgeon populations elsewhere to see if there is any evidence that sturgeon can become infected.