Modeling the habitat distribution of spiny dogfish (Squalus acanthias), by sex, in coastal waters of the northeastern United States

A hierarchical Bayesian approach was used to model the spatiotemporal habitat distribution of spiny dogfish (Squalus acanthias) of both sexes (adults) caught during trawl surveys conducted by the Northeast Area Monitoring and Assessment Program in inshore coastal waters between New England and North Carolina during 2007–2013. The best model for predicting catch per unit of effort (CPUE) for this species includes the following relevant variables: bathymetry, sea surface temperature, salinity, chlorophyll-a (chl-a) concentration, season and time of survey, and a random spatial effect for both sexes. Predicted CPUE was related to depth for both sexes; females occurred in shallower waters than those in which males occurred. Also, more females than males were predicted to occur in warmer, less saline and more productive (higher chl-a concentration) waters. Seasonality and time of predicted CPUE indicated that the abundance of females was higher in inshore coastal waters in the spring and in the morning, and the abundance of males was greater in the afternoon and in the fall in the same area. Collectively, these results provide information that enhances our understanding of differences in habitat selection and spatiotemporal distribution of the 2 sexes of this species—information that can help to modify present management strategies for the U.S. Atlantic fishery