Skip to main content

Stephen R. Carpenter

Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/ecy.1853/full): Predicting species responses to perturbations is a fundamental challenge in ecology. Decision makers must often identify management perturbations that are the most likely to deliver a desirable management outcome despite incomplete information on the pattern and strength of food web links. Motivated by a current fishery decline in inland lakes of the Midwestern United States, we evaluate consistency of the responses of a target species (walleye (Sander vitreus)) to press perturbations. We represented food web uncertainty with 196 plausible topological models and applied four perturbations to each one. Frequently the direction of the focal...
We classified walleye ( Sander vitreus) recruitment with 81% accuracy (recruitment success and failure predicted correctly in 84% and 78% of lake-years, respectively) using a random forest model. Models were constructed using 2779 surveys collected from 541 Wisconsin lakes between 1989 and 2013 and predictor variables related to lake morphometry, thermal habitat, land use, and fishing pressure. We selected predictors to minimize collinearity while maximizing classification accuracy and data availability. The final model classified recruitment success based on lake surface area, water temperature degree-days, shoreline development factor, and conductivity. On average, recruitment was most likely in lakes larger than...
thumbnail
This paper concludes that contaminants in Lake Michigan fishes are likely to remain above detectable levels for some time. Some interest groups have called for measures ranging from additional effluent controls to a ban on the industrial use of chlorine. Such measures, however well intended, are likely to have little impact on many of the contaminants of primary concern. PCBs, in particular, are largely the legacy of past activities and are not likely to be substantially affected by additional regulation. The authors review several options for reducing human exposure to PCBs, using relatively simple fisheries manipulations, although they do not propose that these measures are the ultimate solution to the contaminant...
Categories: Publication; Types: Citation; Tags: BioScience
Abstract (from Ecological Society of America): Successful management of natural resources requires local action that adapts to largerā€scale environmental changes in order to maintain populations within the safe operating space (SOS) of acceptable conditions. Here, we identify the boundaries of the SOS for a managed freshwater fishery in the first empirical test of the SOS concept applied to management of harvested resources. Walleye (Sander vitreus) are popular sport fish with declining populations in many North American lakes, and understanding the causes of and responding to these changes is a high priority for fisheries management. We evaluated the role of changing water clarity and temperature in the decline...
thumbnail
An individual-based model (IBM) was applied to the Lake Michigan rainbow trout (Oncorhynchus mykiss) population, with the objectives of explaining the observed variation in growth and in polychlorinated biphenyl (PCB) concentration within the population. When variation in prey PCB concentration was incorporated into the model, variability in PCB concentration among individual rainbow trout was fully explained by the IBM. Although number of spawnings and number of years spent in a stream prior to first entering the lake were factors in determining growth, these life history characteristics appeared to have only a minor impact on PCB accumulation rate in rainbow trout. The IBM application to the rainbow trout population...
View more...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.