Tagged: fish

by Peter Payette for The Environment Report

The people who manage salmon in Lake Michigan will have to decide soon how many fish to put into the lake.  The salmon fishery is a manmade industry in the Great Lakes.  It’s produced by planting millions and millions of fish in the lakes.  But keeping the salmon population in balance with the food supply is a challenge these days.  And some scientists are raising new questions about the salmon’s demise in Lake Huron and whether that can be stopped in Lake Michigan.  

Salmon were brought in from the Pacific Ocean.

The sport fishery has been on the rocks in Lake Huron for quite some time.

We first reported on the collapse in Lake Huron back in 2006.

That's when Jim Johnson with the Michigan Department of Natural Resources Alpena Fisheries Research Station explained to Lester Graham what was going on:

"There was a huge decline in the amount of nutrients available to zooplankton and phytoplankton in the middle of Lake Huron. These are the basic nutrient bits that fish eat. And it appears now to most of us in the scientific community that a large portion of the nutrients that used enter Lake Huron are now being trapped by zebra and quagga mussels and not finding their way to alewives and other prey fish."

Now we hear news that the state plans to cut salmon stocking in Lake Huron.

From the Associated Press:

Michigan plans a sharp cutback in Chinook stocking in Lake Huron next year, further evidence of the collapse of the lake's salmon fishery.

The state Department of Natural Resources said Friday it will place 693,000 spring Chinook fingerlings in Lake Huron in 2012. That's down from the nearly 1.5 million fed to the lake this year.

Acting DNR fisheries chief Jim Dexter says recreational harvest of Chinook has all but disappeared in the southern two-thirds of Lake Huron. The lake's only productive recreational fishery is in the northern section, where salmon are proving able to reproduce on their own.

Fish biologists blame Huron's Chinook drop-off on the unraveling of the food chain likely caused by invasive zebra and quagga mussels, which have gobbled up plankton needed by forage fish.

Decades ago, residents sued to stop a fish hatchery in northern Michigan from polluting a lake. More than thirty years later, the legal battles have ended and the pollution has been greatly reduced.

Northern Michigan is home to some of the clearest blue lakes in the world, like Torch, Glen and Crystal.

Once upon a time Wilfred Sweicki says Platte Lake in Benzie County was in that league.

“It was extremely clear, never quite as clear as Crystal or Glen but nearly so.”

Unfortunately for Sweicki and other homeowners on Platte, fishery biologists did something nearby that changed the Great Lakes dramatically.

They planted Pacific salmon in the Platte River.

That was in the late sixties and soon a billion dollar fishery was born.

A hatchery was built and animal waste from millions of fish began pouring into Platte Lake. The waste contained the nutrient phosphorus.

Phosphorous caused algae to bloom, clouding the water and killing a variety of aquatic animals and plants.

It even caused chemical changes in the sediment of the lake bottom that produced milky clouds of a clay-like substance that collects on stones and docks.

We've been spending the past couple months going on fishing trips, and talking to people who fish for fun and for a living... to bring you stories about everything you never knew you wanted to know about fish and fishing in the Great Lakes.

Today, you can hear the result of our effort in a special one-hour documentary we're calling Swimming Upstream.

We'll tag along on a salmon fishing trip with Lester Graham, go on an Asian carp rodeo on the Illinois River, meet commercial fishers (both tribal and non-tribal), and go fishing with Dustin Dwyer as he gets into the mind of a fish.

We think of the Lakes today as a great place to play on the beach, to swim, to go fishing. But those huge, beautiful lakes are changing.

The changes are happening so fast that the agencies which manage fishing cannot keep up with them.

On average, a new foreign species gets into the Lakes every seven months. Each could be a threat to the lakes and the fish in the lakes. We explore the health and future of the Great Lakes, and hear stories about fish and the people who catch them.

Listen to it here:

Or tune in today at 1pm and 8pm on Michigan Radio to hear Swimming Upstream and let us know what you think.

Find out more about fish consumption advisories: in Michigan,  in Ohio, in Wisconsin, in New York, and in Illinois.

State officials say they’ve discovered a virus for the first time in wild fish in Michigan. It’s called koi herpesvirus.

Gary Whelan is with the Michigan Department of Natural Resources.

He says the virus might have contributed to the death of several hundred common carp in Kent Lake last June. Whelan says the virus is known to affect common carp, goldfish and koi. And it can be fatal.

The new Michigan Fish Advisory is out.  The advisory lists which Great Lakes fish are fairly safe to eat, and which should be avoided.

In general, blue gill, crappie, yellow perch and rock bass are safer to eat than fish like carp, lake trout, white fish, and catfish.

Women of child-bearing age and children have to be especially cautious about eating too many fish, because chemicals in fish can potentially cause neurological damage.

State toxicologist Kory Groetsch says the level of mercury in locally-caught fish has stayed about the same over the past few decades.