Lake Michigan Fish Populations Seriously Messed Up

[hatrack]

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.

EDIT

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."

EDIT

Sorry, just couldn't come up with an appropriate title phrase to describe the imbalance.

http://story.news.yahoo.com/news?tmpl=story&cid=624&ncid=624&e=2&u=/ap/20041213/ap_on_sc/lake_debate_1

[htuttle]

1. On the bright side, you can hang a Lake Michigan fish up by the head...

...and tell the temperature outside by watching the line of mercury rise.

I do remember Alewives, though. Millions of tiny, stinking, rotting Alewives. Made quite a melange when mixed with the aroma of the rendering and yeast plants in the Menomenee River valley.

[McKenzie]

2. I'm against stocking watercourses/lakes

there is a growing tendency to stock with rainbows over here to satisfy the "recreational" anglers. I fish but I recognise the importance of maintaining natural ecosystems.

Yet another facet of the consumer economy and its malign influence.

[htuttle]

3. People fish wrong anyway

I read about a lake management regime they tried up in Canada sometime back -- I think it was Great Bear Lake.

They changed the rules so that you kept the small fish and threw back the big ones, instead of the other way around. Wouldn't you know, within a few seasons, they had lots of big fish. The same goes for the way people hunt deer. We should be hunting the small ones, not the big bucks.

If we step in and starting controlling bioregions (as we have long ago as far as removing predator species), we should at least attempt to follow the same principles that Nature does.

on edit:
I think I had the wrong lake. I probably still have the wrong lake, but at least it's in Canada now...

[amandabeech]

4. Alewives were an unbelievable mess.

I remember trustees from the local jails down on the beaches shoveling them into trucks.

The lake trout crashed due to the lamprey eel invasions in the '50s when the St. Lawrence Seaway opened, allowing ships, plants and sea life from the oceans of the world into the Great Lakes. Lamprey control was slow to develop, with large electric weirs dropping into all rivers during lamprey spawning season.

I wonder if the alewives eat the algae, etc., cleaned from the Lakes by the Zebra Mussel, another transplant.

One of the big spawning rivers for Lake Michigan, the Muskegon River, still has two old hydro dams blocking much of the original lake trout spawning grounds. Another, the Manistee, still has one dam, I think. Over on the Lake Huron side, the Au Sable River sports several small dams.

I realize that hydropower doesn't spew carbon carrying smoke into the atmosphere, but it does cause some problems with the fish.

I don't know how the Lakes' problems can be solved, but I sure wish that the U.S. and our friends in Canada would spend money on invasive species control.