Abstract.-A creel survey of the sport fishery in Lake Superior and three tributaries (Dead, Carp, and Chocolay rivers) at Marquette, Michigan, during 1984-87 revealed an intensive fishery, mainly for naturally produced trout and salmon. Annual fishing effort in the lake and three tributaries averaged 119,000 and 37,000 angler hours, respectively. Most effort in the lake was by boat (68-84%) but fishing from shore was substantial (16-20%), especially in Marquette Bay (41-51 %). Ice-fishing effort fluctuated considerably among years (1-14%). Effort in the tributaries was mainly by shore angling (69-100%). The Lake Superior sport fishery was particularly active during March-September, with the highest effort in April. Lake Superior anglers fished an average 3.2 hours per trip, whereas those fishing the tributaries averaged 2.1-2.5 hours. Fishing in the tributaries was mainly during April-May and September-October. More fishing was done in the Dead River than in the Carp and Chocolay rivers combined. Over 90% of all anglers surveyed were from Marquette County. Anglers sought mainly lake trout and coho salmon in Lake Superior, and rainbow trout and coho salmon in the tributaries. Salmonid fishes made up most of the catch and were represented by eight species of trout and salmon, one trout hybrid, and two species of whitefish. Most numerous in the catch were coho salmon, lake trout, and round whitefish in Lake Superior, coho salmon and chinook salmon in the Dead River, rainbow trout and coho salmon in the Carp River, and coho salmon and rainbow trout in the Chocolay River. Most trout and salmon caught in Lake Superior were immature, whereas those caught in the tributaries were usually mature fish. In the Lake Superior sport fishery, lake trout averaged 23.5 inches, 4.4 pounds, 8 years old, and the highest monthly catch was in August; coho salmon averaged 16.6 inches, 1.4 pounds, 2 years old, and the highest monthly catch was in April; chinook salmon averaged 25.4 inches, 6.8 pounds, 3 years old, and the highest monthly catch was August; rainbow trout averaged 21.1 inches, 3.6 pounds, 4 years old, and the highest monthly catch was in May; brown trout averaged 17.2 inches, 2.2 pounds, 3 years old, and the highest monthly catch was in March; splake averaged 13.6 inches, 0.9 pound, 2 years old, and the highest monthly catch was in February.
The majority of fish in the catch were naturally produced with the exception of splake and Atlantic salmon at all sites, coho salmon in the Dead River, and brown trout in the Carp River. Hatchery coho salmon provided 80% of the coho catch in the Dead River but 6% or less in Lake Superior, and the Carp and Chocolay rivers. Hatchery rainbow trout made up 15% of the Lake Superior catch and 10-44% of the catch in the tributaries. Hatchery brown trout made up 40% of the catch in Lake Superior and 4-50% in the tributaries. The contribution of hatchery lake trout decreased from 38% in 1984 to 18% in 1987.
Returns from hatchery planting to the sport fishery were less than 2% except for one plant of large yearling splake which was about 13%. Steelhead strains planted in the Chocolay River provided a better return (0.64-1.44%) than either steelhead or domestic rainbow trout planted in Lake Superior (0.08-0.52%). The returns of Siletz steelhead and coho salmon were about 1.4%. Brown trout returns were all less than 1%. These low returns prevented a conclusive assessment of the performance of domestic versus steelhead strains of rainbow trout and yearling versus fall-fingerling brown trout planted in Lake Superior. Straying and mortality both likely contributed to the poor return. Coho salmon planted in Lake Superior strayed as far as Lake Erie and were abundant in the sport fishery and in at least one tributary of Lake Michigan. Michigan should (1) maintain an annual sport fishery creel survey, (2) protect and enhance spawning habitat and populations of native and naturalized trout and salmon, (3) cease planting hatchery trout and salmon, or (4) if some planting is judged necessary, apply documented strategies for improving return to the fishery.