On the surface, Lake Michigan is one of the world's biggest and wildest bodies of freshwater and a popular fishing destination.
BAILEYS HARBOR, Wis. On the surface, Lake Michigan is one of the world's biggest and wildest bodies of freshwater and a popular fishing destination.
But under the surface, the lake has been engineered by humans into a system focused on producing maximum numbers of sport fish, most of which aren't native to its waters.
Each year, the state Department of Natural Resources plants about 13 million exotic salmon and trout, according to a report in Sunday editions of the Milwaukee Journal Sentinel.
The deposits have created what some call a sportsman's paradise, but one that is imperiled.
The salmon begin life in fish hatcheries and are typically unable to reproduce on their own. They are born to be caught.
And this year, they bit on just about anything, said commercial fisherman Dennis Hickey, 62.
He guts salmon for charter fishing customers in Baileys Harbor. Normally, their stomachs are packed with alewives, another saltwater species not native to the lake. But not this year, he said.
"I see this day after day. They're coming in with nothing in their stomachs," Hickey said.
A preliminary survey of the alewives found the population has dropped by a quarter to half in the past year. Theories for the decline include overstocking of salmon and trout, as well as natural fluctuations.
But there also is mounting evidence the lake could be on the brink of "ecosystem shock," a food chain collapse caused by the nonstop invasion of foreign species.
"If something is happening to salmon, it has probably gone way past the point that you ever wanted it to get to," says Steve Pothoven, a University of Michigan biologist.
The Great Lakes Environmental Restoration Act, a bill pending in the U.S. Senate, proposes $6 billion for the lakes in the next 10 years. A similar House bill seeks $4 billion over five years.
They include a directive saying states should coordinate with the federal government to re-establish native species in the Great Lakes.
But even if scientists could figure out how to eliminate the 180 or more exotic and invasive species in the Great Lakes or how to bring back the species that have disappeared, many of the sportsmen and tourist-dependent businesses now hooked on recreational fishing probably would not want them to.
Great Lakes recreational fishing generates about $4.5 billion a year, according to 2002 figures from the U.S. General Accounting Office, and the most prized species are exotic salmon and trout.
Ironically, salmon were brought to Lake Michigan in the late 1960s for two reasons: to create an exciting fishing experience for vacationers and to eat the oceangoing alewives that had infested the lake.
At one time, the lake looked after itself, with big fish living off little fish like chubs, lake herring and bottom-dwelling sculpins. The lake also was home to healthy populations of yellow perch, whitefish and burbot, a cousin to the oceangoing cod.
But the system collapsed in the 1950s when overfishing, habitat degradation and the arrival of sea lamprey caused lake trout to disappear. With lake trout gone and no predator to replace it atop the food chain, alewives flourished.
By the mid-1960s, up to 90 percent of the lake's fish "biomass" was alewife. The bacon-strip-sized fish periodically died off by the billions, though, likely because of temperature swings the ocean species was not built to handle.
Beaches up and down the 307-mile-long lake were choked with mounds of rotting flesh crawling with maggots.
"You didn't even walk by the beach down in Milwaukee. It stunk awful," recalled retired DNR fishery chief Lee Kernen. "They needed bulldozers to clean them up. It was that horrible."
Looking for a more exciting alternative to trout fishing, biologists turned to Pacific salmon. Almost instantly, alewife numbers plummeted and salmon fishing exploded in popularity.
Now, the states of Wisconsin, Illinois, Michigan and Indiana engage in a delicate balancing act to keep enough alewives around to feed the salmon, but not so many that they once again dominate the lake.
The states also annually plant nonnative brown and steelhead trout, and the federal government stocks about 2 million native lake trout -- a species that evolved in the lake over thousands of years but disappeared in the 1950s.
The result is a paradox, however: Politicians and conservationists tout the value of salmon as a reason to protect and restore the lake.
But if the lake were authentically restored, salmon would be among the first species to go.
Some see the most recent plummet in alewives as a second chance to steer the lake away from that "sportsman's paradise" concept and toward a more self-sustaining system.
It is a delicate balancing act, however. Nearly $19 million of the state DNR's $24.7 million 2002-'03 fisheries budget was funded by fishing licenses and salmon and trout stamps.
Source: Associated Press