Publications

Competition for zooplankton between larval lake herring (Coregonus artedi) and lake whitefish (C. clupeaformis) was compared in mesocosm experiments in a small lake. Both species were combined in test enclosures at relative abundances of 1:1 or 1:4 lake herring to lake whitefish at densities of 500; 1, 000; and 2, 000 fish per cage, and were allowed to feed ad libitum on available...

The hypothesis that temperature was an epigamic factor in bloater (Coregonus hoyi) sex determination in Lake Michigan was tested by rearing bloater larvae in the laboratory at 6, 11, and 15 degrees C for the first 80 days after hatching. The percentages of females of fish exposed to the three treatment temperatures did not differ significantly from the expected, 50%. Therefore, the null...

The shortnose cisco, Coregonus reighardi, a member of the endemic species assemblage of Coregoninae in the Laurentian Great Lakes, was commercially important until overfishing and competition pressures from induced planktivores extirpated the species in Lakes Michigan and Ontario. Spawning shortnose ciscoes have been collected from Lake Huron and Georgian Bay of Lake Huron since 1956...

The potential for competition for food between larval lake whitefish (Coregonus clupeaformis) and lake herring (C. artedi) 1- to 8-wk of age was explored in a series of 1-h laboratory feeding studies. Feeding started at 2-wk post-hatch. Learning and fish size appear to be more important than prey density at the onset of feeding. Species differed in their feeding behavior and consumption...

Stocks of walleye (Stizostedion vitreum) were severely depressed in Saginaw Bay in the 1970s. In 1979, the Michigan Department of Natural Resources began intensive stocking of walleye fingerlings to bolster fish populations. Subsequent to stocking, the walleye fishery has recovered. The study objective was to determine if recovery was due to the stocking program or natural reproduction.

Long-term ice records (1823-1994) from six sites in different parts of the Laurentian Great Lakes region were used to show the type and general timing of climatic changes throughout the region. The general timing of both freeze-up and ice loss varies and is driven by local air temperatures, adjacent water bodies and mixing, and site morphometry. Grand Traverse Bay and Buffalo Harbor...

Progress toward lake trout restoration in Lake Michigan is described through 1993. Extinction of the native lake trout fishery by sea lamprey predation, augmented by exploitation and habitat destruction, resulted in an extensive stocking program of hatchery-reared lake trout that began in 1965. Sea lamprey abundance was effectively controlled using selective chemical toxicants. The...

Native lake trout (Salvelinus namaycush) once thrived in the deep waters of eastern Lake Erie. The impact of nearly 70 years of unregulated exploitation and over 100 years of progressively severe cultural eutrophication resulted in the elimination of lake trout stocks by 1950. Early attempts to restore lake trout by stocking were unsuccessful in establishing a self-sustaining population...

The septa lengths of bivalve shells were used to estimate shell lengths of the largest zebra mussels (Dreissena polymorpha) crushed and consumed by freshwater drum (Aplodinotus grunniens) to determine if size limitation could preclude the effectiveness of drum as a biological controller of the zebra mussel. We examined gut samples of drum (273 to 542 mm long) collected from western Lake...

Because the 57-mm-mesh gill net is the predominant gear in the Lake Eric fishery for yellow perch Perca flavescens, gear selectivity is an important factor operating in that fishery. The selectivity curve for age-groups 2–6 is roughly symmetrical with peak vulnerability at age 4; younger and older perch are substantially less susceptible to the gear. The Beverton-Holt yield-per-recruit...

We examined PCB concentration data for seven species of Lake Michigan fishes to determine what trends were apparent °20 yr after PCB restrictions became effective. Total PCB concentrations in all seven species, lake trout (Salvelinus namaycush), rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch)...

The extinction of the native populations of lake trout (Salvelinus namaycush) in Lake Michigan in about 1956 has been followed by a decades-long attempt to reestablish self-sustaining populations of this valuable species in habitats it formerly occupied throughout the lake. One of the most recent management strategies designed to facilitate recovery was to make a primary management...