Publications

Based on acoustic data taken at night and vertically stratified by bottom depth (3–110 m only), the total number (± 95% Cl) of pelagic fishes in Lake Michigan was 43.4 ± 10.1 x 109 or 226.0 ± 55.2 kt in spring (mean density 0.7–3.8 fish·m-2 or 1.6–12.8 ga·m-2) and 115.8 ± 18.3 x 109 or 313.2 ± 74.3 kt in late summer, 1987 (mean density 1.1–7.0 fish·m-2 or 3.0–13.2 g·m-2); approximately...

We report the discovery in April 1986 of the first population of Asiatic clam, Corbicula fluminea, known to occupy a lotic environment in the Laurentian Great Lakes system. This population occupied a 3.8 km long sandy shoal in the discharge plume of a steam-electric power plant on the St. Clair River (Michigan), the outflow of Lake Huron. Samples collected April 1986 to April 1987...

These data, collected during 1942-1944 by Dr. David C. Chandler, describe the density, biomass, and growth of a now extinct population of burrowing mayfly nymphs (primarily Hexagenia limbata) that lived in the sediments of western Lake Erie near South Bass Island. The growth dynamics of this population have not previously been documented. Female nymphs grew faster than males and were...

Contamination of sediments by toxic organic substances and heavy metals was widespread throughout the connecting channels of the upper Great Lakes in 1985. Sediments at 250 stations in the connecting channels were analyzed for total PCBs, oil and grease, phenols, total cyanide, total volatile solids, mercury, cadmium, chromium, cobalt, copper, lead, nickel, and zinc, and the results were

Within the Federal government, the U. S. Fish and Wildlife Service (Service) has primary responsibility for legal and policy responsibility for introduced exotic species. The Lacey Act of 1900 authorizes the Service to prohibit the importation of species that are potentially injurious to native fish and wildlife. However, regulations under authority of the Lacey Act cover only a few...

Abstract has not been submitted

Larval fish samples were collected in plankton tow nets in spring and summer, 1977–1978 and 1983–1984, in the St. Clair and Detroit rivers which are part of the connecting waterway between Lakes Huron and Erie. Larvae abundance of the major forage fish in the rivers are compared with their year-class abundance, as measured by bottom trawl catches of later life stages in Lakes Huron and...

The importance of zooplankton in the diet of yellow perch (Perca flavescens), white perch (Morone americana), walleyes (Stizostedion vitreum vitreum), and white bass (M. chry-sops)was assessed in the central basin of Lake Erie in 1985–1988. Zooplankton were collected by vertical hauls in 1987–1988 and fish with a rock-hopper trawl. Although copepods (calanoid and cyciopoid) were the...

In recent years the National Fisheries Research Center-Great Lakes has ranked the potential hazard to fish and invertebrates of various chemical compounds detected in two Great Lakes fishes-- lake trout, Salvelinus namaycush, and walleye, Stizostedion vitreum vitreum (Hesselberg and Seelye 1982). This hazard assessment has included the identification of the potential sources of the...

Observations made from a submarine showed that the bed-rock surfaces at water depths of about 5 to 14 m on Stannard Rock and Superior Shoal in Lake Superior were covered with a dense, fleece-like blanket of periphyton. Examination of the periphyton revealed it consisted primarily of structurally complex, diverse, diatom communities, but occasional small thalli of the green algae...

Alewives (Alosa pseudoharengus) were first reported in Lake Superior in 1954 and gradually increased in abundance in the late 1950s. In the 1960s and early 1970s, the fish were widespread in the lake but scarce. We determined the more recent abundance and distribution of alewives by cross-contour trawling in the spring in 1978–1988. Alewives were scarce lake-wide; the mean catch rate was...

Data from assessments of fish and zooplankton conducted during April and May-June 1986-88 in south-central Lake Ontario were examined for evidence that zooplankton size structure can be used to follow the movement of alewife (Alosa pseudoharengus). The spring influx of alewife into nearshore waters was linked with water temperature and coincided with a decline in the mean length of...