Assistant Unit Leader Research Fish Biologist
Cooperative Research Units
Email:
twagner@usgs.gov
Office Phone:
814-865-4511
Fax:
814-863-4710
ORCID:
0000-0003-1726-016X
Location
Forest Resources Building
419 Forest Resources Building
University Park
, PA
16802
US
Supervisor:
Duane R Diefenbach
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We present a case-study evaluation of gillnet catches of Walleye Sander vitreus to assess potential effects of large-scale changes in Oneida Lake, New York, including disruption of trophic interactions by double-crested cormorants Phalacrocorax auritus and invasive dreissenid mussels. We used the empirical long-term gillnet time series and a negative binomial linear mixed model to partition variability into spatial and coherent temporal variance components, and we propose that variance partitioning can help quantify spatiotemporal variability and examine if variance structure differs before and after large-scale perturbation. Here, we found that average catch and total variability of catches decreased following...
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Latitudes and longitudes for 45 sites samples for flathead catfish population genetic analyses.
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Abstract (from http://www.tandfonline.com/doi/abs/10.1080/00028487.2012.734892#.VDw7ExYXNyg): Predicting the distribution of native stream fishes is fundamental to the management and conservation of many species. Modeling species distributions often consists of quantifying relationships between species occurrence and abundance data at known locations with environmental data at those locations. However, it is well documented that native stream fish distributions can be altered as a result of asymmetric interactions between dominant exotic and subordinate native species. For example, the naturalized exotic Brown Trout Salmo trutta has been identified as a threat to native Brook Trout Salvelinus fontinalis in the eastern...
Categories: Publication;
Types: Citation;
Tags: Co-occurence,
Fish,
Fish Distribution,
National CASC,
Rivers, Streams and Lakes, All tags...
Stream,
Water, Coasts and Ice,
Wildlife and Plants, Fewer tags
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Poikilothermic animals comprise most species on Earth and are especially sensitive to changes in environmental temperatures. Species conservation in a changing climate relies upon predictions of species responses to future conditions, yet predicting species responses to climate change when temperatures exceed the bounds of observed data is fraught with challenges. We present a physiologically guided abundance (PGA) model that combines observations of species abundance and environmental conditions with laboratory-derived data on the physiological response of poikilotherms to temperature to predict species geographical distributions and abundance in response to climate change. The model incorporates uncertainty in...
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Climate change is expected to result in widespread changes in species distributions (e.g., shifting, shrinking, expanding species ranges; e.g., Parmesan and Yohe 2003), especially for freshwater fish species (Heino et al. 2009). Although anglers and other resource users could be greatly affected by changes in species distributions, predicted changes are rarely reported in ways that can be easily understood by the general public. In contrast, climate science that more directly affects human welfare or livelihoods is often more readily communicated to the general public because it is of greater concern or closely related to everyday life. Read More at http://news.fisheries.org/translating-climate-change-effects-into-everyday-language-an-example-of-more-driving-and-less-angling/.
Categories: Publication;
Types: Citation;
Tags: Eastern Brook Trout,
Fish,
Fisheries,
National CASC,
Rivers, Streams and Lakes, All tags...
Water, Coasts and Ice,
Wildlife and Plants,
angling, Fewer tags
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