When Do Salmon Spawn in Wisconsin?

Salmon spawning is a key part of the natural lifecycle for these iconic fish species in Wisconsin. Understanding when and where salmon spawn provides insights into their ecology and helps guide sustainable fisheries management.

Salmon Species in Wisconsin

There are two main species of salmon that spawn in Wisconsin waters

• Chinook salmon – Also called king salmon Native to the Pacific Ocean but stocked in the Great Lakes

• Coho salmon – Also called silver salmon. Also native to the Pacific and stocked in the Great Lakes.

In the 1960s, these salmon were first brought in to help control populations of invasive alewife. Naturalized spawning populations soon developed.

Salmon Spawning Seasons in Wisconsin

• Chinook salmon begin their spawning migration into Wisconsin tributaries in early summer. Spawning peaks in October and November before tailing off in December.

• Coho salmon migrate and spawn a bit later, from late September through December. Spawning peaks in October and November.

• Spawning times can vary depending on water temperatures, flows, and other environmental factors. But fall is the key season.

• Some Chinook may stray into winter if conditions allow. But most salmon spawn from fall through early winter.

Why Do Salmon Spawn in the Fall?

Salmon are adapted to spawn in fall for several key reasons:

• Fall rain and cooling temperatures trigger the spawning migration from the lakes into the tributary streams and rivers.

• Clean gravel and cobbles in tributaries are great for salmon to build their nests or redds where they will spawn.

• Fall and early winter allow time for eggs to incubate over winter before hatching in spring, giving the young salmon a full season to grow before migrating back to the Great Lakes.

• Salmon eggs and newly hatched juveniles are vulnerable in winter. Eggs incubated in gravels have protection from ice, floods, and predators until spring.

Where Do Salmon Spawn in Wisconsin?

Major tributaries of Lake Michigan and Lake Superior provide the primary salmon spawning habitat in Wisconsin:

• Lake Michigan – Key rivers include the Milwaukee, Sheboygan, Manitowoc, Kewaunee, and Oconto.

• Lake Superior – Important tributaries are the Brule, Bois Brule, Bad, White, and Graveyard Creek.

• Inland streams, the Wolf and Fox Rivers also see some salmon spawning.

• Ideal spawning sites have clean gravel, moderate flows, and quality water for incubation. Dams on some rivers block historical spawning areas.

Watching Salmon Spawns

Viewing salmon spawning in Wisconsin tributaries in fall can be an incredible nature spectacle:

• Brightly colored salmon congregate in riffles and runs, splashing and jumping.

• Females use their tails to excavate depressions in gravel to lay their eggs.

• Male salmon fertilize the eggs as the females deposit them.

• Many salmon die after spawning, providing nutrients to the stream ecosystems.

• Key spots to see salmon spawns include Brule River, Bois Brule River, Strawberry Creek, and Root River.

• Give spawning salmon wide space and avoid disturbing gravel redds. Keep noise and light low.

• Time of day, weather, and water conditions all impact visibility. Weekday mornings often have fewer crowds.

Threats to Salmon Spawning

Several factors can negatively impact successful salmon spawning and reproduction in Wisconsin:

• Dams blocking historical upstream spawning sites force more salmon to crowd into lower tributary reaches.

• Pollution, especially agricultural and urban runoff, degrades water quality which can harm incubating eggs.

• Excess sand and fine sediment fill gravel pores, reducing oxygen flow to eggs. This often stems from erosion.

• Warming water temperatures may reduce egg survival and shift run timing. Climate change poses long-term threats.

• Overfishing on the Great Lakes, invasive species, and disease also harm salmon. Protecting spawning fish is crucial.

• Human disturbance of spawning fish and redds can limit reproduction success.

Salmon Spawning and Fishing

Salmon fishing in Wisconsin is timed around the spawning seasons:

• Most salmon fishing on Lake Michigan and Lake Superior targets salmon gathering to spawn. This concentrates fish for anglers.

• Popular techniques include trolling with spoons and crankbaits near river mouths where salmon stage before moving upstream.

• Snagging or foul hooking salmon is illegal and is especially concerning in smaller spawning tributaries. Ethical anglers avoid this.

• Keeping spawning salmon reduces future populations. Releasing fish helps protect reproduction.

• Fishing for staging and spawning salmon requires care to avoid disturbing redds and habitat. Responsible practices are key.

• Coho salmon runs peak after most tributaries close to fishing on October 15, reducing conflict with spawning fish.