Publications

Human activities have affected the Lake Huron ecosystem, in part, through alterations in the structure and function of its food webs. Insights into the nature of food web change and its ecological ramifications can be obtained through the monitoring of high trophic level predators such as aquatic birds. Often, food web change involves alterations in the relative abundance of constituent...

We used a three-dimensional coupled hydrodynamic-ecological model to investigate how lake currents can affect walleye (Sander vitreus) recruitment in western Lake Erie. Four years were selected based on a fall recruitment index: two high recruitment years (i.e., 1996 and 1999) and two low recruitment years (i.e., 1995 and 1998). During the low recruitment years, the model predicted that...

Fallfish (Semotilus corporalis) are the largest native cyprinid in the northeastern United States and are the most abundant native species in the Salmon River, New York. The Salmon River is a high-quality spawning and nursery river for Pacific salmon (Oncorhynchus spp.) migrating from Lake Ontario. Because of the large number of Pacific salmon spawning in the river in the fall extensive...

Assessments of prey fishes in the Great Lakes have been conducted annually since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. Prey fish assessments differ among lakes in the proportion of a lake covered, seasonal timing, bottom trawl gear used, sampling design, and the manner in which the trawl is towed (across or along bottom contours). Because...

Acoustic surveys were conducted in late summer/early fall during the years 1992-1996 and 2001-2008 to estimate pelagic prey fish biomass in Lake Michigan. Midwater trawling during the surveys provided a measure of species and size composition of the fish community for use in scaling acoustic data and providing species-specific abundance estimates. In 2005, we began sampling Mysis...

The U.S.Geological Survey Great Lakes Science Center has conducted trawl surveys to assess annual changes in the deepwater demersal fish community of Lake Huron since 1973. Since 1992, surveys have been carried out using a 21 m wing trawl towed on-contour at depths ranging from 9 to 110 m on fixed transects. Sample sites include five ports in U.S. waters with less frequent sampling near...

Previous studies support the hypothesis that large numbers of infaunal burrow-irrigating organisms in the western basin of Lake Erie may increase significantly the sediment oxygen demand, thus enhancing the rate of hypolimnetic oxygen depletion. We conducted laboratory experiments to quantify burrow oxygen dynamics and increased oxygen demand resulting from burrow irrigation using two...

The lake whitefish (Coregonus clupeaformis) is one of the native Lake Ontario fishes that declined severely over the past century. Recent evidence of larval lake whitefish production in a historic spawning area (Chaumont Bay) might signal a recovery of this species in New York waters. We surveyed coastal and open water areas to evaluate densities and estimate total abundance of larval...

In the 1990s, the Lake Ontario ecosystem was dramatically altered due to continued invasions of exotic species including dreissenid mussels and predatory cladocerans. We describe the diet and biomass of prey in the stomachs of adult (≥ 109 mm TL) and sub-adult ( 109 mm TL) alewife (Alosa pseudoharengus) in 2004 and 2005 across seasons and depths and compare our results to data from 1972...

The round goby (Apollonia [Neogobius] melanostomus,) an invasive species, is generally smaller and shorter-lived in the Great Lakes than it native range. We examined 30 large male round gobies from trawl samples taken in Lake Huron and used otoliths to determine their age and back-calculated growth. Standard lengths ranged from 76 to 97 mm, and the oldest fish were age-5. Low water...

Expansion of the invasive round goby Apollonia melanostoma (=Neogobius melanostomus) throughout the Great Lakes drainage has created considerable concern among fisheries management agencies. These concerns have led to several studies on the biology and impact of the goby in the basin. However, little information exists on diel patterns in food consumption of the round goby. We examined...

Cisco Coregonus artedi form pre-spawning aggregations in Lake Superior during November with the bulk of spawning occurring during late November through early December (Dryer and Beil 1964). Eggs are broadcast into open water (Smith 1956) with fertilized eggs settling to the lakebed (Dryer and Beil 1964). Peak hatching occurs the following May (United States Geological Survey – Great...