Publications

A new approach was used to evaluate the Wisconsin bioenergetics model for lake trout (Salvelinus namaycush). Lake trout in laboratory tanks were fed alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax), prey typical of lake trout in Lake Michigan. Food consumption and growth by lake trout during the experiment were measured. Polychlorinated biphenyl (PCB) concentrations of...

Three watersheds within a marsh system draining into Lake Michigan in northwest Indiana, USA, were studied for differences among land use, habitat conditions and water quality to determine their influence on macroinvertebrate community structure. Much of this area had been altered for agricultural, commercial, industrial and residential land uses. Land use, habitat conditions and water...

The ruffe, Gymnocephalus cernuus, is a nonindigenous percid in the Great Lakes. Ruffe are aggressive benthivores and forage over soft substrates. Laboratory studies in pools (100 cm in diameter, 15 cm water depth) were conducted to determine whether fish density (low = 2, medium = 4, high = 6 ruffe per pool) changed foraging and aggressive behaviors with a limited food supply of...

No abstract available.

We compared feeding habits and trophic-level relationships of unionid species in a detritus-dominated river and an alga-dominated lake using biochemical analyses, gut contents, and stable-isotope ratios. The δ13C ratios for algae and other food-web components show that all unionids from both the river and the lake used bacterial carbons, not algal carbons, as their main dietary source...

Outcrops of buried soils on lake-plains and glacial headlands along Lake Michigan's eastern shore suggest that periodic dune-building has occurred there after relatively long (≥100 yr) periods of low sand supply. We located, described, and radiocarbon dated 75 such buried soils that crop out in 32 coastal dune fields beside the lake. We assume that peaks in probability distributions of...

Eighty stocked lake trout Salvelinus namaycush (Salmonidae), collected from 2 locations in Lake Huron in May 1995, were examined for parasites. The parasite fauna of this top predator in Lake Huron was characterized by only 6 helminth species. Echinorhynchus salmonis infected all lake trout with a mean intensity of 163.9. The intensity of this acanthocephalan species significantly...

The restoration and rehabilitation of the native fish communities is a long-term goal for the Laurentian Great Lakes. In Lake Superior, the ongoing restoration of the native lake trout populations is now regarded as one of the major success stories in fisheries management. However, populations of the deepwater morphotype (siscowet lake trout) have increased much more substantially than...

Recruitment to the adult population of white bass Morone chrysops in Lake Erie sharply declined during the early 1980s. To explain this phenomenon, we formulated the following four hypotheses: (1) the biological characteristics of adult spawners changed during the early 1980s, so that the ability to produce eggs decreased; (2) the decrease in phosphorus loadings to Lake Erie during the...

Burrowing mayflies of the genus Hexagenia spp. were widely distributed (ca. 80% of sites) and abundant (ca. 160 nymphs/m2) in the western basin of Lake Erie of the Laurentian Great Lakes in 1929–1930, prior to a period of anoxia in the mid 1950s. Nymphs were absent or rare in the basin between 1961 and 1973–1975. In 1979–1991, nymphs were infrequently found (13–46% of sites) in low...

Abstract has not been submitted

Adults of the cladoceran Daphnia lumholtzi, native to Australia, Africa, and parts of Asia, were first collected in August 1999 in Lake Erie. Individuals were collected near East Harbor State Park, Lakeside, Ohio from vertical plankton net tows. The average number of D. lumholtzi that were found (0.03/L) indicate that D. lumholtzi is beginning to establish itself in Lake Erie. The...