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Full-Text Articles in Physical Sciences and Mathematics
Multiscale Analysis Of Factors That Affect The Distribution Of Sharks Throughout The Northern Gulf Of Mexico, J. Marcus Drymon, Laure Carassou, Sean P. Powers, Mark Grace, John Dindo, Brian Dzwonkowski
Multiscale Analysis Of Factors That Affect The Distribution Of Sharks Throughout The Northern Gulf Of Mexico, J. Marcus Drymon, Laure Carassou, Sean P. Powers, Mark Grace, John Dindo, Brian Dzwonkowski
University Faculty and Staff Publications
Identification of the spatial scale at which marine communities are organized is critical to proper management, yet this is particularly difficult to determine for highly migratory species like sharks. We used shark catch data collected during 2006–09 from fishery- independent bottom-longline surveys, as well as biotic and abiotic explanatory data to identify the factors that affect the distribution of coastal sharks at 2 spatial scales in the northern Gulf of Mexico. Centered principal component analyses (PCAs) were used to visualize the patterns that characterize shark distributions at small (Alabama and Mississippi coast) and large (northern Gulf of Mexico) spatial scales. …
Gulf-Wide Decreases In The Size Of Large Coastal Sharks Documented By Generations Of Fishermen, Sean P. Powers, F. Joel Frodrie, Steven B. Scyphers, J. Marcus Drymon, Robert L. Shipp, Gregory W. Stunz
Gulf-Wide Decreases In The Size Of Large Coastal Sharks Documented By Generations Of Fishermen, Sean P. Powers, F. Joel Frodrie, Steven B. Scyphers, J. Marcus Drymon, Robert L. Shipp, Gregory W. Stunz
University Faculty and Staff Publications
Large sharks are top predators in most coastal and marine ecosystems throughout the world, and evidence of their reduced prominence in marine ecosystems has been a serious concern for fisheries and ecosystem management. Unfortunately, quantitative data to document the extent, timing, and consequences of changes in shark populations are scarce, thwarting examination of long-term (decadal, century) trends, and reconstructions based on incomplete data sets have been the subject of debate. Absence of quantitative descriptors of past ecological conditions is a generic problem facing many fields of science but is particularly troublesome for fisheries scientists who must develop specific targets for …