‘We can’t regulate ourselves’ out of whitefish crisis, experts say

• Michigan’s iconic whitefish are nearing collapse in lakes Michigan and Huron because of invasive mussels that have gobbled up a key food source
• Experts told state regulators that restrictions on fishing won’t be enough to stop the species’ decline
• Bridge Michigan is spending the summer covering the crisis and its impact on Michigan’s economy, culture and environment

More research into how to stem the scourge of invasive mussels is needed if Michigan has any hope of revitalizing the collapsing lake whitefish population, fishery experts told state regulators Thursday. 

The experts also advised the state to take up “emergency corrective action” like transferring adult whitefish to different spots in lakes Michigan or Huron, stocking more fish or rearing them for longer.

The Michigan Natural Resources Commission took no action following the presentation from Michigan Department of Natural Resources experts.

Efforts to restrict commercial and recreational anglers from plucking too many whitefish out of the water are important, but reducing the spread of invasive quagga mussels that have culled the food sources for young fish needs to be the main target, Steve Lenart, a DNR fish biologist, told the commission.

“There’s no regulatory fix for what the problem is, which is the survival of young fish,” he said.

Lenart delivered the presentation alongside DNR Fisheries Chief Randy Claramunt. 

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While state and national bodies figure out how to limit the number of mussels in the Great Lakes, Lenart said, continuing to research and monitor populations of whitefish and their food sources will help the DNR better address the crisis.

The presentation to fish and game regulators came after Bridge Michigan launched a summerlong investigation into the causes and consequences of Michigan’s lake whitefish collapse. 

State and tribal fishery managers this year reduced catch limits in central Lake Michigan by 94%. Meanwhile, some recreational and commercial anglers have stopped fishing of their own accord, figuring the fish are now so scarce it’s no longer worth the time and effort.

The decline of the industry worries Claramunt, who said “the commitment to monitor, the commitment to assess and try these new things will be lost” without the economic incentive.

Populations of whitefish, long a mainstay of the Great Lakes diet, fishing industry and ecosystem, have plummeted in recent years as invasive mussels tighten their grip on the Great Lakes food web.

Those small, filter-feeding bivalves first arrived in the Great Lakes decades ago, but in recent years have expanded their territory to cover nearly every inch of the lakebed in lakes Huron and Michigan. There, they gobble up the phytoplankton that many other species also rely upon for survival.

Whitefish are especially dependent on plankton during their first months of life, when their mouths are too small to target bigger prey. 

With precious few plankton left in the water, those fish now hatch into a veritable desert and starve to death soon thereafter.

In many parts of the lakes, the average whitefish hauled up in fisherfolks’ nets is now more than 20 years old — born before the mussels ripped a hole in the food web. The absence of younger fish is a clear sign of a looming collapse, experts say.

Those aging adult fish may die out before humans find a way to suppress the mussels that hinder their reproduction, experts say. 

And the trickle of whitefish that make it to adulthood are “not going to be able to replenish the adults to be able to reproduce,” Claramunt said

State and tribal fishery managers have tightened restrictions on whitefish harvests, but some argue that’s a futile effort, reasoning that, as long as the mussels dominate the lakes, the whitefish are doomed either way.

“Number one, we got to do something about the mussels,” Claramunt said. “If we don’t do something, the future is going to be grim for whitefish.”

And it’s not just whitefish: The lack of food caused by the mussels makes survival more difficult for all manner of Great Lakes fish. Salmon are struggling too, and scientists fear that less well-studied fish, like burbot and suckers, are also in decline.

Scientists are searching for a weapon to kill off the mussels, but so far have not identified one that’s effective in a vast setting like the Great Lakes. Fearing that time is running out, some scientists have begun last-ditch experiments that aim to convince whitefish to spawn in rivers, where their hatchlings could find more food. But it will take years to know whether those efforts are working. 

Other projects that use biological, chemical or mechanical controls to remove mussels from individual reefs — while small — can’t be written off, Lenart said.

“It’d be easy to say it’s too small, we could never do this, you can’t scale it out, but you gotta try right?” Lenart said.