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Stephen Riley

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Monitoring of vitamin B1 (thiamine) in the eggs of lake trout (Salvelinus namaycush) collected from lakes Huron and Michigan has been conducted by the U.S. Geological Survey since the mid-1990’s. The results of this monitoring effort have been used by natural resource management agencies and native American tribes within the Great Lakes basin to evaluate the reproductive health of lake trout. The data in this release are the thiamine concentrations measured in lake trout collected from 1996-2018. Results are reported as total thiamine (nmol/g-egg), collection site, lake, year collected, and reference to the analysis methods.
Categories: Data; Tags: Canada, EMS, Early Mortality Syndrome, Fish, Fish Spawning and Larval Aggregation, All tags...
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Resilience science provides a conceptual framework and methodology for quantitatively assessing the ability of a system to remain in a particular state. Probable non-linear ecological responses to global change, including climate change, require a clear framework for understanding and managing resilience. However, much of the resilience research to date has been qualitative in nature, and frameworks developed for the implementation of resilience science have been either vague or focused on the social component of social-ecological systems. Attempts to quantify resilience and operationalize the concept include the cross-scale resilience model, discontinuity theory and the early detection of leading indicators of...
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Description of Work A Department of Interior team, including U.S. Geological Survey (USGS), Fish and Wildlife Service (FWS), and National Park Service (NPS), is working to determine why botulism outbreaks, which have killed large numbers of fish and fish-eating birds, are occurring in the Great Lakes. This project will determine: 1) a quick assay test for the presence of the toxin , 2) how birds are exposed to the toxins, and 3) what factors combined trigger an outbreak. This information will be used to formulate management strategies. Botulism intoxication is caused by ingestion of neurotoxins produced by the bacterium Clostridium botulinum. Periodic outbreaks of type E botulism have resulted in die-offs of fish...
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Diet analyses were performed on juvenile lake trout (Salvelinus namaycush) captured by bottom trawl during annual USGS Great Lakes Science Center demersal fish community surveys in mid-October to mid-November 2008–2017 in Lake Huron. This dataset contains lake trout capture information (e.g., location, depth) and diet item data (taxa consumed and their associated lengths).
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