Coastal Revolution In Lake Michigan?

Jul 10, 2014

Credit Michigan Sea Grant

Lake Michigan was recently recognized as one of the best places in America to fish for bass. The booming fishery is one sign of what might be a major shift of the lake’s food web. One biologist recently referred to the change as a "revolution."

Even though there are winners, like people fishing for bass, the change is being driven by an invasive species. And it could mean trouble for the most popular sport fish in Lake Michigan.

Chris Noffsinger has an unusual specialty as a fishing guide. He shows you where to catch bass.

Most charter fishing up north is for salmon, which are often three or four times the size of the biggest bass. Noffsinger worked on salmon boats as a teenager. Once he owned his own business, he decided to switch.

“I really enjoy the bass side of things,” he says. “On days off from salmon fishing, I’d be out bass fishing.”

Chris Noffsinger
Credit Peter Payette

Noffsinger is busy these days. He’s been on the water every day but five since the end of April. He often fishes in Grand Traverse Bay, which Bassmaster.com recently named the ninth best place to fish for bass in the U.S.

Noffsinger says the fishing has always been good here, its just been getting more attention in recent years. But he says the fish are changing.

“They’re getting fat,” he says. “We caught one the other day that was 21 inches long and had a 20-inch girth, so it was as fat as it was long.”

Researchers say the smallmouth bass in northern Lake Michigan are some of the fattest in the country. It’s no mystery why. They are eating round gobies, a little bait fish native to the Caspian and Black Seas.

Gobies first showed up here about twenty years ago. Now, they’re everywhere.

Dave Clapp manages the state’s research station in Charlevoix and says goby are thick in the rocky areas where smallmouth bass tend to congregate.

“You can see 100 gobies in a square meter of the bottom of the lake,” says Clapp. “So they’re real plentiful when you get in the habitat that’s appropriate for them.”

Immeasurable food supply

The most recent estimate from the U.S. Geological Survey suggests gobies now make up about one fourth of the food available to big predator fish in Lake Michigan.

John Janssen thinks that estimate is low. He’s a biologist at the University of Wisconsin-Milwaukee. Janssen says the annual surveys are done in sandy areas of the lake. So he believes the survey only samples a small part of the total goby population.

“It’s trivial compared to what’s on the rocky habitat,” he says.

Janssen referred to the expanding goby population in Lake Michigan as a “coastal revolution” in a presentation he gave last year.

The implications could be drastic.

Gobies are known to carry a type of botulism that has killed thousands of shorebirds along the lake. Also, a goby boom does not help the most popular sport fish in the lake, salmon.

The food supply for salmon in Lake Michigan has been dwindling for years. But the gobies won't help because Pacific salmon hardly eat them.

“The salmon pretty much evolved as a herring predator,” Janssen says. “The way its mouth is shaped is adapted for feeding in the water column. They apparently don’t even look down in the rocks for gobies.”

If salmon can’t thrive in Lake Michigan, it would be an economic blow to cities like Frankfort, Manistee and Ludington. Those ports have many charter fishing businesses.

But Janssen sees some upsides to the goby, since native fish like bass and lake trout are filling up on them.

He says if managers are looking to stock a monster sport fish like salmon, they could look at brown trout. That fish species seems to like gobies, too. Two of the three largest brown trout ever caught in the world, on record, came out of Lake Michigan in the past five years.