Publications

Quantitative polymerase chain reaction (qPCR) measurement of enterococci has been proposed as a rapid technique for assessment of beach water quality, but the response of qPCR results to environmental conditions has not been fully explored. Culture-based E. coli and enterococci have been used in empirical predictive models to characterize their responses to environmental conditions and...

Based on data from our annual lakewide bottom trawl survey of Lake Michigan, we determined that density of ninespine sticklebacks Pungitius pungitius increased from an average of 0.234 kg/ha during 1973–1995 to an average of 1.318 kg/ha during 1996–2007. This greater-than-fivefold increase in density coincided with the dreissenid mussel invasion of Lake Michigan. Intervention analysis...

Lianas and other climbers are important ecological and structural components of forest communities. Like other plants, their abundance in a given habitat depends on a variety of factors, such as light, soil moisture and nutrients. However, since lianas require external support, host tree characteristics also influence their distribution. Lianas are conspicuous life forms in tropical...

Temperature is one of the most important environmental influences on aquatic organisms. It is a primary driver of physiological rates and many abiotic processes. However, despite extensive research and measurements, synoptic estimates of water temperature are not available for most regions, limiting our ability to make systemwide and large-scale assessments of aquatic resources or...

Future alterations in land cover and climate are likely to cause substantial changes in the ranges of fish species. Predictive distribution models are an important tool for assessing the probability that these changes will cause increases or decreases in or the extirpation of species. Classification tree models that predict the probability of game fish presence were applied to the...

Stocking levels of Chinook salmon Oncorhynchus tshawytscha for Lake Ontario have been highly controversial since the early 1990s, largely because of uncertainties about lakewide abundance and rates of prey consumption. Previous estimates have focused on years before 1995; since then, however, the Lake Ontario ecosystem has undergone substantial changes, and there is new evidence of...

We estimated mean depths of capture for offshore demersal fish species, grouped into three habitat-based guilds (shallow benthic, pelagic, and deep benthic), using fall bottom trawl data (27–73 m) in the western main basin of Lake Huron from 1976 to 2007. The mean depth of capture of the shallow and deep benthic guilds initially exhibited a trend toward capture in shallower water...

The Northern Refuge was established in 1985 as part of the lake trout Salvelinus namaycush rehabilitation effort for Lake Michigan. To evaluate progress toward lake trout rehabilitation in the Northern Refuge, we conducted annual (1991–2008) gill-net surveys in the fall to assess the adult population and beam trawl surveys in the spring to assess naturally reproduced age-0 lake trout...

Double-crested cormorant (Phalacrocorax auritus) diets were compared with evidence from the stomachs of shot birds and from regurgitated pellets at High Bluff Island and Little Galloo Island, Lake Ontario. The highest similarity in diets determined by stomach and pellet analyses occurred when both samples were collected on the same day. Diet overlap dropped substantially between the two...

Cladophora in the Great Lakes grows rapidly during the warm summer months, detaches, and becomes free-floating mats as a result of environmental conditions, eventually becoming stranded on recreational beaches. Cladophora provides protection and nutrients, which allow enteric bacteria such as Escherichia coli, enterococci, Shigella, Campylobacter, and Salmonella to persist and...

Walleyes Sander vitreus are stocked into Owasco Lake, New York, to provide a sport fishery, but the population must be sustained by annual hatchery supplementation despite the presence of appropriate habitat. Therefore, we evaluated walleye spawning success in Dutch Hollow Brook, a tributary of Owasco Lake, to determine whether early survival limited recruitment. Spawning success during...

In 2005, 2008, and 2009, eggs were collected for analysis of total thiamine fiom 2, 58, and 30 gravid rainbow smelt (Osmerus mordax) captured in Edgewater Creek, Owasco Lake, New York, respectively. Mean egg thiamine concentrations (nmollg i standard error) in 2005, 2008, and 2009 were 6.0 ± 1.8, 13.3 ± 0.5, and 14.9 ± 0.2, respectively. Eggs from three more females in 2009 were manually...