Coho Stocking and Migration

By Judy Nugent - November 1, 2006
With spring just around the corner, fishermen in Indiana and Chicago are already thinking of Coho. With any luck these fish will be heading to southeastern Wisconsin by April 15th. Several variables influence the actual migration patterns and timing, including stocking rates and weather. With ice already melting in the southern most regions of Lake Michigan, the young Coho will soon come together in an annual migration.

Over the past several years, the Wisconsin DNR has stocked 500,000 fish annually, including 400,000 yearlings. These figures do not include stocking by other states including Michigan and Indiana. According to Brad Eggold, Wisconsin DNR Lake Michigan Southeast Region fisheries supervisor, "Coho are stocked each spring. The fish average 10-14 fish per pound or 6-7 inch fish. Fingerlings are smaller at 18-20 fish per pound." However, crowding in the hatcheries has forced the DNR to do more stocking of fingerlings of late. Where before they would stock 400,000 yearlings and 100,000 fingerlings, Eggold says now it is closer to 50/50. "Its too bad," says Eggold, "because a Root River and Kewaunee River study showed that the yearlings return at twice the rate."

In addition to Coho stocking, the DNR also stocks Chinook salmon. The Coho are not as effective a predator as the Chinook. The DNR keeps tabs on the forage base and if there is a significant decline in numbers, they adjust the Chinook stocking accordingly, not the Coho. But these smaller Coho still know how to eat. The current thinking is that the young two year old Coho congregate near Indiana because they are foraging the alewives. Due to variables still not understood by the DNR, these two year old fish sometimes move up the Wisconsin shore and other years move up the Michigan side. At this stage of their life cycle they are 1-3 pounds. By the end of the summer they can be as large as 20 pounds.

In the fall the Coho head back to the individual river in which they were stocked. The mass migration and intermingling of Wisconsin and Michigan stocked fish is over as they head for specific streams. It is here that they die, ending a two year life cycle. Since the 1970's the DNR has noticed a pattern in Coho harvest numbers. In years when the Chinook harvest is high, the Coho harvest is low. This is also true of other species. Says Eggold, "We see an inverse proportion. When Chinook are hot the other fish aren't targeted by fishermen. The guys don't go deep for Rainbows or hit the humps for Lake Trout." Past charter boat harvests of Coho are as follows: 2000=27,000, '01=12,000, '02=26,000, '03=13,000, and '04=20,000. It looks like the '05 charter harvest should be around twelve to thirteen thousand Cohos. Regardless, since 1994 these have been above average and indicate a healthy fishery. On April 9th there is a stocking conference where it is expect there will be no changes to the current Coho management.

In April the fish will start their migration north. The good news for anglers is that they can be caught near shore. Pier fishermen and boats can find schools of Coho chasing after bait fish. Sometime the fish can be seen breeching the surface. Common fishing techniques include suspended worms under a bobber, suspended bait fish, or small spoons (usually 2/3 oz. green and silver or blue and silver Cleos; or small silver Krocodiles) with 6-8 pound line. Avoid fishing if your casts can't get you beyond the "mud line." Coho seem to avoid this murky water which tends to stay close to shore in the early season. Instead cast or use a boat to get just beyond the mud. Coho are looking for warmer waters near shore and will not be farther out in the lake.

Author Judy Nugent
Judy Nugent
Judy Nugent has been writing for several years. Her work can be found in Wisconsin Outdoor News, Wisconsin Outdoor Journal, Wisconsin Sportsman, Midwest Outdoors, Fly Fisherman Magazine and Snowshoe Magazine among others. She is also on the TV show OUTDOOR WISCONSIN. Judy has experience in radio with the show Great American Outdoor Trails where she does a weekly segment called Women on the Trail.