Chinook Salmon
Oncorhynchus tschawytscha

Common Names: Chinook Salmon, King Salmon, Spring Salmon, Blackmouth, Tschawytscha, Chin, King

Lake Michigan Sports Catch in Wisconsin: 200,000-300,000 per year

Preferred Temperature Range: 50-57 °F

Length: 20-35 inches

Weight: 5-35 pounds.

State Record: 8/25/83; 43 pounds, 3 ounces, Lake Michigan

Identification: Adults are iridescent green to blue‐green on the back and top of the head. The sides are silvery, turning to white on the belly. They have black spots (at least a few) on the upper half of their body and on all fins. Chinook differs from coho salmon and other Great Lakes salmonids by having grey or black mouth coloration with teeth set in black gums, a squared tail with spots on both halves, and 15‐19 rays in the anal fin.

Coho Salmon
Oncorhynchus kisutch

Common Names: Coho Salmon, Coho, Silver Salmon, Blueback, Sea Trout

Lake Michigan Sports Catch in Wisconsin: 75,000-200,000 per year

Preferred Temperature Range: 54-57 °F

Length: 11-26 inches

Weight: 5-12 pounds.

State Record: 8/17/75; 24 pounds, 6 ounces, Lake Michigan

Identification: Adults are steel blue to slightly green on the back, brilliant silver on the sides, and white on the belly. There are small black spots on the back, sides above the lateral line, base of the dorsal fin, and upper half of the caudal fin. Coho differs from the Chinook and other salmonids of the Great Lakes by having the inside of their teeth set in white gums, their tail slightly forked with spots on the top half, and having 12-15 rays in their anal fin.

Brown Trout
Salmo trutta

Common Names: Brown Trout, German Brown Trout, German Trout, European Brown Trout, Brownie, Brown

Lake Michigan Sports Catch in Wisconsin: 40,000-60,000 per year

Preferred Temperature Range: 65-75 °F

Length: 16-30 inches

Weight 2-16 pounds

State Record: 8/23/78: 32 pounds, 8 oz. Lake Michigan
Identification: Brown trout caught in Lake Michigan have an overall silverish color with “X” shaped marking on the back and the upper half of their body, a squared tail, small and numerous spots on their head, the inside of their mouth white, and 12 or fewer rays in their anal fin. Spawning brown trout in September and October will have an overall tan to reddish brown color with distinctive black and red spots.

Lake Trout
Salvelinus namaycush

Common Names: Lake Trout, Laker, Grey Trout, Mackinaw, Great Lakes Trout

Lake Michigan Sports Catch in Wisconsin: 100,000 per year
Preferred Temperature Range: 48-52 °F

Length: 17-36 inches

Weight: 3-30pounds

Length: 17-36 inches

Weight: 3-30pounds

State Record: 6/1/57: 3 pounds, 4 oz. Big Green Lake, Green Lake County

Identification: Lake trout are distinguished by having a deeply forked tail, the inside of their mouth white, and 10-11 rays in their anal fin. The color of the lake trout varies from light green or grey to dark green or almost black with light spots and worm-like markings on their back and sides.

Rainbow Trout
Oncorhynchus mykiss

Common Names: Rainbow Trout, Rainbow, Bow, Steelhead Trout, Steelhead, Kamloops Trout, Silver Trout

Lake Michigan Sports Catch in Wisconsin: 40,000-60,000 per year per year

Preferred Temperature Range: 53-57 °F

Length: 16-30 inches

Weight: 2-16 pounds

State Record: 8/19/73: 24 pounds, 4 oz. Lake Michigan

Identification: Rainbow trout from Lake Michigan has an elongated and slightly compressed body, a squared tail covered with spots, 12 or fewer rays in the anal fin, and the inside of the mouth white. There are generally small spots on the top of the head and back above the lateral line, including the dorsal and adipose fins. Body color is variable, with the back being darker, ranging from steel blue to green to almost brown; the cheek and sides are silvery, occasionally with a pink to red lateral stripe; and the bottom or belly is silvery white.

Questions and Answers about the fish…

Why isn’t there a special snagging season for salmon on some rivers?

The biggest reason is that the majority of the fishing community does not consider snagging to be a fair way to catch trout and salmon, and snagging also interferes with other types of fishing. In addition, many snaggers catch the fish simply to collect the eggs from the fish, leaving the carcass to rot on the streambank. This is a waste of the resource and can lead to public health concerns.

How does one distinguish Seeforellen Brown Trout from “German” Brown Trout? and do “German” and Seeforellen browns run at different times?

Seeforellens and “German” browns are different strains of the same species. Seeforellens can be distinguished by fin clips, although only fish stocked in the Menominee, Kewaunee and Root Rivers are generally clipped. Differences in the time of spawning and age at maturity can also be used to distinguish each strain from the other, but physically the fish are very similar. The “German” or Domestic strain of brown trout may begin staging in harbor mouths for their spawning run beginning in July, with the majority of the run occurring in September and October. The spawning run for Seeforellens generally occurs in November and December. The age at which the fish matures is also a distinguishing characteristic of each strain, with the Domestic brown trout maturing at 2-3 years of age and the Seeforellen at 3-4 years. This later age of maturity in the Seeforellen usually allows for greater growth before their first spawning.

Where do all the trout and salmon go after spawning?

All coho and chinook salmon die after spawning as part of their life cycles. Brown trout, steelhead, and brook trout do not automatically die the following spawning, although some will die simply from old age, stress from spawning or an infection such as fungus brought on by spawning activity. Depending on their age, some trout will return to Lake Michigan.

How can you distinguish a non-spawning fish as male or female?

From the outside, it is difficult, although male steelhead often exhibits greater head length than females. The most definitive way to tell is to cut the fish open.

I see a small yellow mark on Chinook salmon, what is it?

The short answer is that the yellow mark is a condensed area of pigment, much like a birthmark. There is no pathological significance of the mark. This yellow mark IS NOT a mark applied by agencies to determine stocked versus naturally reproduced trout and salmon. All marking of stocked salmonids in Lake Michigan and Lake Huron are accomplished with traditional fin clips.

BKD — What is it? Where is it from? Are infected fish edible?

BKD stands for Bacterial Kidney Disease, an internal infection caused by the bacterium Renibacterium salmoninarum. External signs of the disease include “Popeye” and small closed blisters or fluid-filled blobs between the skin and muscle. Internally, the kidneys are most often affected, becoming swollen and developing discrete white areas that contain bacteria. BKD was present in the first eggs obtained from Pacific salmon. Outbreaks appear to occur when fish are stressed from lack of sufficient forage. Fish showing signs of BKD are generally in such poor condition that, at the very least, renders the flesh unpalatable.

Does the absence of any fin clips on a lake trout mean that some are reproducing naturally?

Not likely, since the number of unclipped fish captured in surveys and documented in the creel survey is very small. The absence of clips is generally due to fish being missed during clipping or from the regeneration of fins. A dramatic increase in the number of unclipped fish above historical levels might indicate an increased natural reproduction.

Are there any splake or whitefish or tiger hybrids in Lake Michigan?

Splake, which is a cross between a brook trout and a lake trout, are stocked on a regular basis into Green Bay. Lake whitefish are native to Lake Michigan and the population has been increasing in recent years. Round whitefish, or Menominees, are also native to Lake Michigan and their numbers are secure. Tiger trout, which are a cross between a brook trout and a brown trout, were stocked into the Wisconsin waters of Lake Michigan from 1974 through 1977. The program was discontinued due to poor returns.

Are spawning fish (in the rivers) any less safe to consume?

The Department publishes advice on how much fish people can safely consume due to contaminants. Fish consumption advice for Lake Michigan trout and salmon species is the same whether those migrating species are caught in Lake Michigan or in one of its tributaries. A special study was conducted and showed that for Lake Michigan trout and salmon migrating into tributaries, the fish do not accumulate additional amounts of contaminants after entering the river or stream.

Fish that die after spawning, like chinook and coho salmon, may be less palatable since they do not feed during their spawning runs and their muscle tissue begins to break down. Fish that do not die after spawning, like steelhead, brown trout, and brook trout, are generally in much better condition during spawning.

How many eggs are there in a female coho salmon? Female steelhead?

There are 1,000 to 3,000 eggs in a female coho salmon, depending on the size of the fish. A female steelhead may contain 3,000 to 5,000 eggs, depending on the size and age of the fish.

How do you tell the difference between the strains of steelhead?

Although there are slight differences in body conformity, fin clips are used to positively identify the strains of steelhead. This is why all steelhead stocked into Root and Kewaunee Rivers (brood streams) are fin-clipped. Knowing the strain of the fish prevents breeding of one strain with another.

How old are the fish when they spawn?

Coho salmon generally spawn at 2+ years (two summers in the lake). Some male cohos will spawn after only one summer in the lake. The majority of steelhead spawn at 3 and 4 years, with some spawning at 5 to 6 years. The oldest steelhead spawned at the Root River Steelhead Facility was an 8-year-old male. The majority of chinook salmon spawn after spending 2 to 4 summers in the lake. A chinook spawning after 4 summers in the lake would be 3+ years old since they are stocked as spring fingerlings that are less than a year old. Brown trout typically spawn at age 2 to 4.

Why don’t trout and salmon reproduce naturally?

The spawning streams on the Wisconsin shoreline of Lake Michigan are not conducive to natural reproduction of trout and salmon because the summer water temperatures are too high for the survival of trout fingerlings and heavy loads of sediment smother eggs incubating in the stream bed.