Scientists See Superior Plankton Crash Now Underway In Huron - Free Press

[hatrack]

Lake Superior is big, clear and beautiful, yet in terms of fish production it's a near desert compared to the other Great Lakes. Now fisheries scientists say changes they started seeing in Lake Huron a few years ago might mean that the second-biggest of the Great Lakes is on its way to becoming an equally unproductive version of Superior. Until three years ago, anglers landed about 75,000 chinook salmon a year at the Lake Huron sampling stations run by the state Department of Natural Resources and the Ontario Ministry of Natural Resources.

Last year, that figure was 11,500, in part because anglers became so discouraged that the fishing effort decreased. The salmon caught were undersized and skinny. And alewives, their primary prey, had been reduced to almost zero, which means there is little hope of a salmon recovery any time soon. The good news is that with salmon numbers down so much, biologists are seeing a small but significant resurgence in lake trout, the original top predator in Lake Huron. The state and federal governments have spent a lot of money trying to rehabilitate the lake trout.

EDIT

The problem apparently starts with some of the smallest creatures in the food chain. Mary Balcer of the University of Wisconsin-Superior studies these tiny creatures. She found that fish can get much more energy by eating a tiny shrimp called diaporeia than from many other kinds of zooplankton. But diaporeia have almost disappeared from most of Lake Huron for reasons scientists have yet to figure out, although they suspect that diaporeia and other zooplankton can't compete with exotic zebra and quagga mussels that invaded the lakes.

EDIT

Anglers want simple answers to questions like: "What happened to the salmon in Lake Huron?" We want someone to say, "Oh, we can just stock more game fish," or "we can start stocking smelt and other bait fish." Unfortunately, it isn't that easy. There's no point in stocking prey fish or game fish if there's not enough for the prey fish to eat, especially the young prey fish. "We used to think the alewives disappeared because the salmon ate them all," said Jim Johnson, a DNR research biologist. "Now we learn from Mary Balcer's work that the alewives had the rug pulled out from under them when the zooplankton crashed,"

EDIT/END

http://www.freep.com/apps/pbcs.dll/article?AID=/20060323/SPORTS10/603230534/1058

[longship]

1. What is it going to take?

All these kind of things are like canaries in the mine. Yet we are ignoring all of it.
At our own peril.

[donsu]

2. ah the Food Chain - remember learning that in school?

well because of global warming that Food Chain is beginning to lose a lot of links.

you know what they say about chains - the weakest link - what about missing links????

tick, tick, tick

[Dead_Parrot]

3. The missing links

are in the Whitehouse.

[donsu]

4. we better get them out of there and back into the food chain

nt