|
| |
|
| |
|
|
|
March 27, 2005
Kings in exile: Lake MichiganSalmon vacate Huron after forage base collapseByRecord-Eagle staff writer  Record-Eagle/Josh Biggs Charter fisherman Leo Marchlewski, of Bay City, has watched the salmon on Lake Huron dwindle in numbers and get smaller in size. "It's gotten so easy for people to catch fish now, anywhere from Grand Haven up," the Manistee resident said. But the chinook, or king salmon, boom on Lake Michigan corresponds with a bust on Lake Huron. Salmon numbers on the state's east side are falling so far, so fast that many discouraged local anglers dismiss nearby Huron and trailer their boats cross-state for a chance at the brawny game fish. Lake Huron charter captains, meanwhile, bemoan the loss and ponder their future. State Department of Natural Resources studies show chinook salmon increasingly are leaving Huron's waters for Lake Michigan, most likely because of a decimated supply in Huron of their favorite food, the alewife, a small, silver-and-green herring. The Huron salmon decline worries charter skippers like Leo Marchlewski, owner of Adventure Charters in Bay City. "We're finding fewer fish and smaller fish," Marchlewski said. "Last year was really bad. "I probably did only half as many charters as the year before. If I don't do better than I did last year, I won't have my boat inspected for charters again." Biologists are trying to learn what role invasive species such as the zebra mussel and round goby may play in disrupting the food chain and souring the salmon fishery. And some fret the Huron alewife crash and salmon flight may signal similar trouble in Lake Michigan. At stake is a salmon-fishing tourism industry estimated at more than $4 billion a year throughout the Great Lakes. Fishermen typically flood the state's top salmon ports throughout the summer and up to Labor Day in search of the hard-pulling chinook. Where Michigan's most prized sports fish goes, anglers and their dollars surely follow. Don LeForce, an avid chinook fisherman from West Branch, said he and his friends for years fished almost exclusively in Presque Isle County and elsewhere along the Huron shoreline. "We're going to Manistee now," he said. "It's just better, and that's been the trend in the last five years or so." Salmon on the move Biologists use a coded wire-tagging program to examine behavior of a percentage of the nearly 4 million chinook salmon planted annually by the Great Lake states and the Canadian province of Ontario. Salmon are tagged as "fingerlings," in their first year of life, when they're about 3 inches long. A machine injects the fish's snout with a small piece of coded wire, no bigger than a sliver. Its adipose fin, located on its back near the tail, is then clipped, so biologists and anglers can readily identify them when they catch a tagged fish. Fish heads are returned to designated DNR collection stations and biologists compile the data. Among the things biologists can track is where a salmon is caught relative to where it was introduced to the Great Lakes. And those numbers have dramatically changed in recent years. Only 4.3 percent of the juvenile class of chinook planted in Lake Huron in 1996 eventually were caught in Lake Michigan. By the 2000 class, the number of Huron-planted chinook caught in Lake Michigan was at 8.3 percent. It then shot to 18 percent of the 2001 class; 29 percent of the 2002 class. Only eight of the many thousands of young ***TAGGED???*** chinook planted in Huron in 2003 have thus far been caught, said Jim Johnson, fisheries biologist at the DNR's Alpena research station. Seven of them were caught in Lake Michigan, he said. Catch reports from anglers also back up the chinook Huron-to-Michigan migration trend. Surveyors interview fishermen at docks and cleaning stations, asking how long they fished and how many fish of various species they caught. In 1997, anglers caught nine chinook salmon per 100 hours of fishing on Lake Huron; four per 100 hours on Lake Michigan, said John Clevenger, DNR code-wire tagging program leader. The Lake Michigan numbers for last year were more than triple that - 14 chinook caught per 100 hours. The Lake Huron numbers, meanwhile, dropped last year to seven chinook caught per 100 hours of fishing. What's happening on Lake Huron is no mystery to Johnson, the DNR fisheries biologist. "It corresponds exactly with when the alewives started to disappear," he said. "The bottom line is, the alewives are gone on Lake Huron." Chinook swim up to 2,500 miles from their spawning stream to feed when in their native Pacific Ocean habitat, Johnson said. Most Huron-planted chinook likely stayed put in the past because they didn't have to go far to find the food they needed. As that began to change, it was nothing for chinook planted as far south on Huron as the Thumb area to end up far down the Lake Michigan side. "Their way of staying alive is finding food every day, and they've found the mother lode of alewives in Lake Michigan, which is off Ludington," Johnson said. "Until just last year we tended to think of the lakes as quite separate systems. We need to recognize the chinook salmon find the prey wherever it is." Invasive species' role Johnson cites two likely culprits for the alewives' disappearance on Huron - an unexpected explosion in natural reproduction of chinook there in the 1990s, and the spreading impact of invasive species on the Great Lakes ecosystem. Nutrients in the lake that once were utilized by phytoplankton and small freshwater crustaceans are now trapped inside zebra mussels and their lesser-known but perhaps more disruptive relative, quagga mussels, Johnson said. That disruption at the bottom of the food chain reverberates all the way to the top to the chinook and other large species, he said. "In most systems where the prey collapse like this, the predators suddenly have the rug pulled out from under them," he said. State and federal governments must work harder to protect the Great Lakes fishery by getting tougher on ocean-going vessels releasing bilge water in the Great Lakes, said Onekema charter boat captain Frank English, president of the Michigan Charter Boat Association. "The stuff they are pumping in is hurting our lakes and hurting them bad," he said. Lake Michigan next? Anglers everywhere on the Great Lakes report catching smaller salmon. That indicates there is greater competition for available food, Johnson said. Some of Lake Huron's predator-prey imbalance problems may eventually come to Lake Michigan, if they aren't already developing there. Preliminary findings from a Wisconsin DNR survey last fall show Lake Michigan alewife populations down 25 to 50 percent, The Milwaukee Journal-Sentinel reported in December. The next two years will be unlike any seen since salmon were brought to the Great Lakes in the mid-1960s, Johnson said. "The chinook last summer were the smallest I've ever seen them," he said. "This summer we're forecasting the smallest population we've seen in about 10 years. "The $64,000 question is, is this Lake Huron situation a preview of what's going to happen in Lake Michigan? The answer is, nobody knows." See Related Story: Invasive species spawned fishery
|
|
