AP file photo A fisherman shows off a walleye that he had reeled in while fishing.

Last week we explored how walleye are tagged and released and how you can partner with biologists by reporting your catches of tagged fish. Here is the rest of the story.

The reported tag returns from anglers and other captures are used by biologists, in this case Dave Fielder at the Alpena Fishery Station, to estimate movement, harvest rate, and survival patterns over the years. This column will look at how these tagged fish and biological data from DNR fishery surveys have documented a recent, second major expansion of the Saginaw Bay walleye population and how this recent surge has bolstered catches of walleye along the entire Michigan coast of Lake Huron.

Remember, in earlier columns I reported that it was the collapse of alewives (which were eating most of the just-hatched walleye) that fired the initial recovery of walleye in Lake Huron. That was during the early 2000s.

Then, since about 2016, an amazing second, and even bigger, surge in walleye reproduction is propelling Saginaw Bay’s walleye into the stratosphere. Dr. David Fielder of the Alpena Fishery Station told this story to the DNR’s Lake Huron Advisory Committee in April.

But, first, I want to point to all the kinds of data Dave uses to “populate” his Lake Huron walleye models – the principal tools he uses to make these estimates. Dave’s walleye population models look at trends in walleye catches in DNR fishery surveys, by anglers, and in the commercial fishery that operates in Ontario’s waters of Lake Huron. It estimates how many walleye die each year from each of these harvest sources and from natural mortality and how old these walleye were. His models’ data series began in the late 1980s and is expanded each year with the latest data. I am not the mathematician that Dave is, and to me his model is an amazing achievment and a critically important tool to estimate Lake Huron’s walleye population.

Dave, like many research biologists, thinks in terms of numbers/math and expresses outcomes with good communication skills so that he can share his results with managers who make the decisions about future management of Lake Huron – as he did with the Lake Huron Advisors last month. You could say Dave speaks two languages, mathematics and Engilish. Every fish Dave collects is converted to numbers, such as length, weight, age, and numeric codes for what it ate, its sex, and maturity (will it spawn next year?). Lamprey wounding is also coded. The model reconciles all observations about walleye in the commercial and recreational fisheries, and DNR survey catch, to make estimations (calculus is involved here. I remember in school thinking I could dodge heavy math by

studying fish. WRONG!). But the work is not complete until its findings are communicated to Dave’s agency partners on Lake Huron and with the pubic.

Dave performed that last step in April. Here are some of the findings Dave reported at the Lake Huron Advisory Committee last month.

Lake Huron’s walleye numbered about 2 million adult fish in the late 1990s and was 80% hathery (stocked) fish. That number doubled to 4 million fish by 2006, thanks to the alewife collapse. Finally, walleye were spawning again and stocking was suspended in 2006. At that time, most wild walleyes were spawned in tributaries to the Saginaw River.

Then, beginning in about 2016, walleye numbers experienced an even bigger surge and reached 14 million adult fish by 2024. That’s one walleye per acre of Lake Huron, counting Ontario’s Georgian Bay and North Channel, only counting walleye originating from Saginaw Bay. Other, much smaller, walleye populations contribute to Lake Huron’s fishery.

But here is what is different and explains this latest surge. Until recently almost all walleye reproduction was in the tributaries of Saginaw Bay. But now only 35% come from tributaries; 65% come from spawning sites in Saginaw Bay. No one knows for sure why spawning has shifted from rivers to the Bay, but it could represent recovery of spawning sites in the Bay from years of pollution and sedimentation. It might also represent emergence of a walleye strain genetically “programmed” to spawn in the bay rather than migrate up the Saginaw River tributaries.

Whatever the cause, Lake Huron is now arguably the best walleye recreational fishery in the US. Recreational harvest of walleye in Saginaw Bay reached a record high of over 500,000 in 2025, a 61% increase over 2024, and the increase should continue into 2026. Walleye have now surpassed trout and salmon in number of fish harvested in the Michigan waters of the Great Lakes. Thanks to this walleye explosion, there are more fishing trips to Lake Huron than lakes Superior, Michigan, and Erie combined – and most of this fishing is in the Saginaw Bay area.

The economic value of the Saginaw Bay recreational fishery is over $60 million annually to Bay area motels, restaurants, and fishing-related businesses.

But this is more than a Saginaw Bay story. Based on tag returns (thank you, anglers, who reported their tagged-fish catches), Dave estimates that each year approximately 4 million walleye migrate north from Saginaw Bay to northeast Michigan’s coast. These migrants tend to be larger than those that remain in the Bay and are worth targeting in the Alpena area. The northward surge of walleye from their spring spawning sites is happening right now.

Saginaw Bay is probably the finest walleye recreational fishery in the US. Now is the time to target the northward migration of these walleye to our local waters.

Be sure to visit the new Besser Museum Fishery Heritage Exhibit this June, where you can learn more about our shared Great Lakes fishery heritage.