Publications

My purpose here is to review historic changes in the major fish resources of the five Great Lakes, and to identify the cause or causes for those changes. In some instances it will be clear that intensive fishing was the primary cause of change; in other instances it will be nearly as clear that predation by the sea lamprey played a significant if not dominant role in change; and in still...

Sampling of benthos at 166 stations in the lower two-thirds of the St. Marys River in 1974 and 1975 yielded a total of 9 mayfly and 20 caddisfly genera. Densities of mayflies (primarily the pollution sensitive Hexagenia) ranged from 0 to more than 2,000/m2 and caddisflies (primarily Polycentropus) from 0 to 744/m2 in individual samples. No mayflies were collected in a 20 km section of...

A part of the connecting channel system between Lake Huron and Lake Erie, the Detroit River forms an integral link between the two lakes for both humans and biological resources such as fish, nutrients, and plant detritus. This profile summarizes existing scientific information on the ecological structure and functioning of this ecosystem. Topics include the geological history of the...

Most studies of the relationships between freshwater macrophytes and phytomacrofauna, or the macroinvertebrates associated with the macrophytes, have been based on individual plant collections or samples from monotypic plant stands. We describe the phytomacrofauna assemblages within naturally occurring, taxonomically mixed stands, and consider how macrophyte surface area and plant...

This study demonstrates the feasibility of using low-altitude aerial photography to inventory submersed macrophytes in the connecting channels of the Great Lakes. For this purpose, we obtained aerial color transparencies and collateral ground truth information about submersed vegetation at 160 stations within four study sites in the St. Clair and Detroit rivers, September 17 to October 4...

Seasonal growth and occurrence of an exotic submersed aquatic macrophyte, Nitellopsis obtusa, was monitored at the head of the Detroit River of the Great Lakes from June 1984 to April 1985.Nitellopsis obtusa first appeared in early July, increased in biomass from July to September, remained at relatively high biomass from September to late January, and decreased substantially as ice...

The slimy sculpin (Cottus cognatus), spoonhead sculpin (Cottus ricei), and deepwater sculpin (Myoxocephalus thompsoni) are abundant fishes in Lake Superior. Slimy and spoonhead sculpins occupy a zone from near shore to depths of 210 m but are generally most abundant in waters 50 to 90 m deep. Deepwater sculpins are found in waters from 15 to 407 m deep and are most abundant at depths...

The St. Clair River and Lake St. Clair form a part of the connecting channel system between Lake Huron and Lake Erie. This report synthesizes existing information on the ecological structure and function of this ecosystem. Chapters include descriptions of climatology, hydrology, and geology of the region; biological characteristics; ecological relationships; and commercial and...

We made 16 paired releases of lake trout Salvelinus namaycush of four year classes (1979–1982) at five locations to compare survival and growth of hatchery-reared fish stocked as fall fingerlings (FF) and as spring yearlings (SY). Comparisons were based on fish at ages 2–8 recovered with bottom trawls, with gill nets, and from anglers' catches. Mean lengths and weights were greater for...

We determined the relative toxicities to the aquatic crustacean Daphniz pulex of six heterocyclic nitrogen compunds. These compounds were selected because they were detected in lake trout or walleyes and were commercially available. Stress to the daphnid populations may affect forage fish populations that depend either directly or indirectly on zooplankton as a food source in the Great...

Of the six classes of chemicals potentially hazardous to Great Lakes aquatic biota, derivatives of polyaromatic hydrocarbons (PAHs) were the most acutely toxic (48-h EC 50) to Daphnia pulex. The other classes, listed in order of decreasing toxicity were alkyl halides, nitrogen-containing compounds, cyclic alkanes, heterocyclic nitrogen compounds, silicon-containing compounds. O f the 41

The National Fisheries Research Center-Great Lakes of the U.S. Fish and Wildlife Service has extensively used a side scan sonar to survey and pinpoint lake trout spawning grounds in the Great Lakes. The Geographic Information System (GIS) of the National Ecology Research Center produced maps from the side scan sonar data showing the exact location of the spawning grounds; this will...