Fishing for Answers
Written by Detroit Free Press   
Sunday, 06 May 2007 14:24

After starting out as hot as a $2 pistol, coho salmon fishing cut off abruptly at the extreme southern end of Lake Michigan this past week, and charter captains worried that the fish might have been affected by a newly discovered disease called viral hemorrhagic septicemia.

The good news is biologists have assured the captains that it's unlikely that VHS has caused the salmon to disappear.

The bad news is that southern Lake Michigan is showing early signs of a bottom-up collapse in the food chain seen on Lake Huron before that lake's salmon fishery was decimated, and that alewife numbers in southern Lake Michigan are about 30% lower than last year's levels.

And the even worse news for all Great Lakes area anglers is that new federal and state rules aimed at containing VHS will be announced this spring, and they likely will include:

• Limiting the use of live bait in some lakes and rivers to baitfish that the anglers catch themselves on those waters.

• Limiting or banning the transportation of trailerable boats between some waters, especially when moving between Great Lakes basins.

• Banning or limiting the use of spawn (fish eggs) as bait, because most spawn comes from Pacific Ocean or Great Lakes waters that have had outbreaks of VHS.

• Banning frozen herring because it comes from infected areas and the virus is known to live in frozen fish.

• Increased costs to state fisheries agencies that will no longer be able to use the same water sources in fish hatcheries but will have to drill wells.

• Decreased numbers of fish available for stocking lakes and rivers because of higher hatchery costs.

• Requiring fishing shops to buy bait from sources that can prove the bait has been tested and is VHS-free, which will increase the cost of bait.

"We limited out on cohos on 26 out of 28 trips when we started this year," said Dave Engel of Saugatuck, the skipper of the charter boat Best Chance Too.

Engel, who starts the salmon season in Indiana, added, "Then they just disappeared. We don't know what happened. The last few days, we've been catching a lot of lake trout, but the cohos are gone.

"Some of the (captains) are worried that we're already seeing the effects of VHS, but I don't think that's the problem. We're not seeing any dead fish floating. When we had the problem with BKD (bacterial kidney disease) a few years ago, you could see dead fish floating everywhere.

"I think the fish have just moved west earlier than usual," he said, adding that he had heard that anglers along the Illinois and Wisconsin coasts were beginning to catch cohos.

But Indiana fisheries biologist Brian Breident is worried about the reason the cohos moved.

"Our problem more likely is that lower part of the food chain," Breident said. "It's not as productive as it used to be, probably because of zebra and quagga mussels (invasive filter-feeders from the Baltic Sea). We don't know if the cohos left because they were following bait or because they're trying to find food."

Breident said the cohos could have moved on early because the spring weather has been strange, with alternating hot and cold spells and unusually cool water.

In an annual spring survey in 2005, Breident said, biologists found that southern Lake Michigan lake trout were eating about 70% alewives and 30% round gobies and perch. In 2006, it was about 50% alewives and 50% gobies and perch.

"There just weren't any alewives for the lake trout to eat," he said.

Biologists had thought Lake Michigan could avoid a Lake Huron-style collapse because the southern end of Michigan is shallower, warmer and productive enough to fuel the food chain for the whole lake. Now they're not as confident, Breident said.

While the windy spring has made it tough for anglers to go offshore, the salmon they are catching in Michigan waters are about the same size as last year, said Jim Dexter, Lake Michigan fisheries manager for the DNR.
 
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