- Great Lakes miracle
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In 30 years, an active program of lake management
has turned Lake Michigan from a black hole to one
of the Midwest's favorite fishing holes.
The thousands of anglers who plumb the depths of Lake Michigan on summer mornings in search of monster coho, steelhead and chinook are enjoying some of the nation's best salmon and trout fishing. They may not know, however, they are also enjoying the fruits of a "modern management miracle." That's how UW-Madison zoologist and Great Lakes expert James Kitchell views the incredible comeback of sport fishing in Lake Michigan - a comeback which he helps maintain through research. "We went from zero - absolute zero - in the value of recreation for Lake Michigan to an overwhelming success," he says. "In coastal communities, the lake used to be their back door, where they threw their junk. That perspective has now rotated 180 degrees." Lake cities like Racine, Port Washington, Sheboygan, Two Rivers and Algoma all have sparkling new marinas packed with boats, and local motels are filled with anglers from across the Midwest. Wisconsin is only one part of the booming Lake Michigan sport fishery, which generates nearly $1 billion per year in regional economic activity. It didn't exist 30 years ago. The lake was an ecological disaster, Kitchell says. By the early 1960s, native lake trout had all but vanished due to overfishing and the widespread invasion of parasitic sea lamprey. With predatory fish gone, populations of forage fish like the alewife ex-ploded. During summer, millions of fish washed up on the lakeshore. The introduction of hatchery-raised trout and salmon helped lead the coastal turnaround. Stocking of up to 15 million salmon per year since the 1970s has created a healthy sport fishery and helped restore the predator-prey balance in the lake. But without constant research and manage-ment, the lake could easily sink to its past degraded conditions. Through the UW-Madison Sea Grant Institute, Kitchell and other research-ers are developing new computer-analysis tools to help managers maintain the best stocking and parasite-control practices. Kitchell's computer models create a total "energy budget" for the predators, which tells managers how many sport fish the available forage fish base can sustain. It can help managers make predictions and stock the appropriate species to create predatory fish populations without over-taxing the lake's available food. It's a delicate balance, Kitchell says. In 1989, the culmination of years of salmon overstocking led to another massive summer fish kill - except this time, it was salmon that succumbed to disease, weakened by a lack of food. With computer models that estimate the
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impact of stocking practices, Kitchell says fish managers can avoid these costly shocks on the food chain. Kitchell's group also is working to find the best population balance between sport fish and native lake trout, which are less desirable to anglers but important in bringing a natural balance to the lake. Another long-term goal is to reduce reliance on hatchery-raised fish, since they are vulnerable to disease and boom-and-bust cycles. Finally, Kitchell and others constantly monitor the control and spread of exotic species such as the sea lamprey, the main culprit in the collapse of the Great Lakes fisheries. Without continuous control of the parasite, he says, the Great Lakes' resurgent fishery could not exist.
"We went from zero - absolute zero - in the
value of receation for Lake Michigan
to an overwhelming success."
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