Publications

Most of the PCB body burden in lake trout (Salvelinus namaycush) of the Great Lakes is from their food. PCB concentrations were determined in lake trout from three different locations in Lake Michigan during 1994–1995, and lake trout diets were analyzed at all three locations. The PCB concentrations were also determined in alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax)...

Lake trout Salvelinus namaycush, aged 3 and 6 years and with average weights of 700 and 2,000 g, were grown in laboratory tanks for up to 407 d under a thermal regime similar to that experienced by lake trout in nearshore Lake Michigan. Lake trout were fed alewifeAlosa pseudoharengus and rainbow smelt Osmerus mordax, prey typical of lake trout in Lake Michigan. Of the 120 lake trout used...

At present, rainbow smelt appear to represent a key component of the eastern Lake Erie fish community as they are the dominant prey for virtually every open water predator, and are harvested directly by an important Ontario commercial fishery. In response to concern over the status of rainbow smelt in eastern Lake Erie, our objective was to quantify some primary top down forces of...

From 1993 to 1997, 60 species of Anisoptera (dragonflies) and Zygoptera (damselflies) were found in Lake and Porter Counties, Indiana, including Indiana Dunes National Lakeshore, in contrast to 34 species that were recorded historically from this region. We added 17 new species to Lake County's odonate records and 39 new species to the 5 previously recorded in Porter County. Several...

In Lake Baikal, three morphotypes of omul Coregonus autumnalis migratorius are recognized; the littoral, pelagic, and deep-water forms. Morphotype assignment is difficult, and similar to that encountered in pelagic and deep-water coregonines in the Laurentian Great Lakes. Principal component analysis revealed separation of all three morphotypes based on caudal peduncle length and depth...

Juvenile (postsmolt) coho salmon (Oncorhynchus kitsuch) were held in fresh water in the laboratory at 5, 10, 15, and 18A?C for 8 weeks and fed freshly thawed, juvenile alewives (Alosa pseudoharengus) at rates equal to 1 and 2 % of their wet body weight/day, and also at the ad libitum or unrestricted ration rate. Most rapid growth in weight (1.2% wet body weight/day) occurred among fish...

We tested the hypothesis that the efficiency with which fish retain polychlorinated biphenyl (PCB) congeners from their food strongly depends on Kow and degree of chlorination of the congener. We used diet information, determinations of concentrations of individual PCB congeners in both coho salmon (Oncorhynchus kisutch) and their prey, and bioenergetics modeling to estimate the...

This article chronicles the ascent, dominance, and decline of the alewife (Alosa pseudoharengus) in the Great Lakes and tracks the gradual accumulation of knowledge on the fish's effect on the aquatic community. Changes in management strategies for alewife are followed, and the current management dilemma is framed in light of the alewife's effect on inidigenous fishes and the changing...

Forage base allocation, which has become an important issue because of major changes in the fish communities and fisheries of the Great Lakes since the 1950s is examined and documented in this chapter. Management initiatives that were used to address the issue, and supporting research and development that provided new or improved methods of field sampling and analysis are also...

Aquatic algal communities are sensitive to environmental stresses and are used as indicators of water quality. Diatoms were collected from three streams that drain the Great Marsh at Indiana Dunes National Lakeshore. Diatom communities, water chemistry, and land use were measured at each site to test the hypothesis that differences in land use indirectly affect diatom communities...

The Calumet Region was shaped by geologic forces, succession, and interacting biomes converging on a unique natural landscape. Over the past 4500 years, a strand plain has formed to the north of a geologic area called Toleston Beach. Sequential and differential primary succession of dune and swale communities in this region allowed species from different biomes to interact freely. In the...

The process of apoptosis, often coined programmed cell death, involves cell injury induced by a variety of stimuli including xenobiotics and is morphologically, biochemically, and physiologically distinct from necrosis. Apoptotic death is characterized by cellular changes such as cytoplasm shrinkage, chromatin condensation, and plasma membrane asymmetry. This form of cell suicide is...