Waves of dead alewives created a rotten situation this summer in shoreline communities from Muskegon to Charlevoix, but the die-offs could be a positive sign for Lake Michigan anglers and Department of Natural Resources officials concerned with dwindling bait fish populations in recent years.

The small 2- to 9-inch prey fish migrated to the Great Lakes from the Atlantic Ocean in the 1920s, and they served as the primary food source for salmon in the decades after they were introduced to Lake Michigan in the 1960s.

But invasive quagga and zebra mussels filtered out the food source for alewives in more recent decades, which prompted the DNR and other Lake Michigan fisheries managers to reduce salmon stocking over past the decade to balance predator and prey fish in the lake.

Jay Wesley, the DNR’s Lake Michigan basin coordinator, said the stocking cuts and declines in salmon reproduction are likely now fueling a comeback for alewives that’s leading to both this year’s die-offs and plans to increase salmon stocking in Lake Michigan in the future.

Alewife numbers “had been going down and bottomed out around 2016, then came up year after year to stabilize around 100 kilotons in 2021,” Wesley said. “In 2016, they were down to about 20 kilotons or lower.”

Wesley believes the rebound is associated with an increase in near-shore food sources, though there’s several theories on what’s leading to the die-offs that were once more common.

“The water appears to have more algae and zooplankton in it compared to five or six years ago,” he said. “In the deep waters, the water is still really clear.”

“We haven’t seen an alewife die-off in probably 10 years,” Wesley said. “There’s a lot of theories [on the cause]. Alewives are moving north earlier … in the spring. That could introduce them to more temperature changes that stressed them out.

“Being so dense and so close to shore, there may also be issues with them finding food,” he said.

Bill Winowiecki, a Glen Arbor charter boat captain and president of the Michigan Charter Boat Association, said the die-offs confirm a trend that’s been obvious to big lake anglers the last couple years.

“The charter boats have been telling the DNR we’ve been seeing more alewives and this sort of proves it,” he said.

The situation is also lending support to calls to increase salmon stocking in response. DNR officials crafted a proposal last year to increase chinook plants from 650,000 per year currently to 1 million, a measure that would add one site at Ludington State Park’s Big Sable River that was cut from the stocking schedule years ago. The proposal would also increase stocking at Medusa Creek in Charlevoix, the Little Manistee River, and other sites, Wesley said.

“When we (cut back on stocking) all you had was luck of the draw to catch one,” Winowiecki said. “We need some salmon up here badly.”

DNR officials submitted the proposal last year to a multi-jurisdictional Lake Michigan Committee, which consists of representatives from Wisconsin, Illinois, Indiana and the Chippewa Ottawa Resource Authority – the governing body for tribal fisheries.

But the proposal did not gain approval because the committee wanted to monitor lakewide stocking increases from 2019, and COVID complicated data collection in 2020, Wesley said.

“We reintroduced it this year and there seems to be a lot of public support for it so far,” he said. “The groups I’ve talked to and the charter boat people I’ve talked to are supportive.”

A decision from the Lake Michigan Committee would come by late July, and, if approved, the DNR would open the plan up to broader public comment in the coming months before a final decision by mid to late September, so extra eggs could be collected this fall.

The alewife die-offs and signs of a healthy salmon population in Lake Michigan bode well for the proposal, Wesley said.

“The health of the fish (salmon) has been fantastic,” he said. “This year we’re seeing more younger fish in the catch, which indicates to us survival has been better in recent years.

“We also know wild reproduction will increase too,” Wesley said.

Lake-wide, between 50 to 60 percent of salmon caught are naturally reproduced, while that figure is closer to 80 percent on the Michigan side of the lake, Wesley said.

“We’ve been waiting over 20 years to see this,” Wesley said. “If this die-off is a sign of the major comeback of alewives, that’s a good thing.”

As the stocking proposal moves forward, Michigan Sea Grant, Michigan State University researchers and others are working to develop a new model that more closely examines the impact of all predator fish on the forage base.

“It will give us a better idea of how to forecast how stocking decisions” impact the predator-prey balance, Sea Grant educator Dan O’Keefe said.

Organizers are hoping to finish the project by the end of the year after delays from COVID and hiring issues slowed progress last year. Mark Breederland, O’Keefe’s counterpart based in Traverse City, said Sea Grant will solicit public feedback on the model to ensure it balances the perspective of interested stakeholders with the objectives of fisheries managers.

“We’re trying to provide the linkage between the public and the model so they can have input into it,” he said.

Pictured: Alewives washed ashore at Esch Road Beach in the Sleeping Bear Dunes National Lakeshore, photographed July 11, 2022 by Linnea Carlson deRoche