Publications

The present study was conducted to determine impacts of zebra mussel [Dreissena polymorpha (Pallas, 1771); Dreissenidae] infestation on unionids in firm substrata in western Lake Erie. Unionid mollusks were collected at a total of 15 stations on three offshore depth contours (2, 3, and 4 m) in 1983 (before zebra mussel infestation), in 1990 and 1993 (after zebra mussel infestation), and...

Freshwater unionid clams in North America have been virtually eliminated from waters that are colonized by zebra mussels. Near total mortality has been reported in western Lake Erie, but we have discovered a large population of native clams in a Lake Erie wetland that shows little sign of infestation. Field observations and laboratory experiments show that warm summer water temperatures...

The morphology of pharyngeal teeth of freshwater drum (Aplodinotus grunniens) was studied to determine changes that occur during growth of drum that may relate to consumption of zebra mussel (Dreissena polymorpha) by larger fish. Pharyngeal teeth were of three types. Cardiform teeth were replaced by villiform teeth, which were replaced by molariform teeth as the size class of drum...

Remote-sensing techniques that can be used to quantitatively characterize the physical habitat in large rivers in the United States where traditional survey approaches typically used in small- and medium-sized streams and rivers would be ineffective or impossible to apply. The state-of-the-art remote-sensing technologies that we discuss here include side-scan sonar, RoxAnn, acoustic...

In this study we examine genetic variation within and among self-sustaining lake trout populations from the Great Lakes basin, the Rainy Lake basin, and Yellowstone Lake. We used RFLP analysis and direct sequencing to examine DNA sequence variation among several mitochondrial and nuclear genes, including highly conserved loci (e.g. cytochrome b, nuclear exon regions) and highly variable...

The stomach contents of 31 lake herring (Coregonus artedi), captured by anglers from western Lake Superior in the winters of 1993–1995, were examined to determine if predation on rainbow smelt (Osmerus mordax) was occurring as indicated by anglers. Twenty-six (84%) of the stomachs contained rainbow smelt, with an average of 7.0 rainbow smelt/stomach. This was the first documentation of...

Barrier dams, traps, and lampricides are the techniques currently used by the Great Lakes Fishery Commission to control sea lampreys {Petromyzon marinug) in the Great Lakes. To augment these control techniques, a sterile-male-release research program was initiated at the Lake Huron Biological Station. Male sea lampreys were sterilized by intraperitoneal injection of the chemical...

We documented the age and growth of alewives Alosa pseudoharenqus in Lake Ontario during 1978-1992 and determined if growth was affected by intraspecific competition for epilimnetic zooplankton, lake temperature, or demand of salmonine piscivores for prey. Ages of juvenile alewives were determined from scales during 1978-1983, and ages of juvenile and adult alewives were determined from...

We examined parasites of 152 lake herring (Coregonus artedi) collected from three locations in Wisconsin waters of Lake Superior in 1994, four locations in Wisconsin waters in 1996, and one location in Minnesota waters in 1996 to determine; 1) the species composition and relative abundances of parasites in lake herring, 2) the differences in parasite relative abundances across locations...

Gillnet selectivity for lake trout (Salvelinus namaycush) was estimated indirectly from catches in nets of 102-, 114-, 127-, 140-, and 152-mm stretch measure. Mesh selectivity was modeled as a nonlinear response surface that describes changes in the mean, standard deviation, and skewness of fish lengths across mesh sizes. Gillnet selectivity for lake trout was described by five...

Restrictions on the release of PCBs into the environment began in the early 1970s, resulting in reduced PCB concentrations in Lake Michigan bloaters (Coregonus hoyi). However, since 1980, PCB concentrations in bloater have declined only slightly. The bloater population also increased 40-fold during 1970 through 1984, resulting in a diet shift and a density-dependent decline in growth...

We found mean target strength to be a reliable in situ predictor of fish weight, which allows direct estimation of the pelagic planktivore fish biomass from target strength measurements. Fish were collected by midwater trawling concurrent with target strength measurements (120-kHz frequency) in Lake Michigan. The mean weight of fish caught ranged from 2 to 71 g and mean target strength...