Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States

Delineation of Bull Shark Nursery Areas in the Inland and Coastal Waters of Louisiana

Jason K. Blackburn, Julie A. Neer, and Bruce A. Thompson


Abstract.—In order to synthesize current information on bull sharks in Louisiana waters, data sets were gathered and analyzed from a variety of previously published and unpublished sources. This included information from research conducted at Louisiana State University, other universities, and state agencies. Six separate data sets representing six geographic regions were used in this synthesis. Descriptive statistics were calculated for biological and environmental parameters for all data sets. Primary and secondary nursery areas were delineated with convex polygons constructed within a geographic information system by connecting the inner and outermost sampling locations of each study site and smoothing the lines connecting each point. All six geographic locations were delineated as containing both primary and secondary nursery areas. A regular occurrence and high abundance of young bull sharks in Louisiana’s inland waters indicate that low salinity and freshwater environments serve as both primary and secondary nursery areas and should therefore be considered essential fish habitat for bull sharks.