Globally, bycatch in tropical/subtropical shrimp trawl and longline fisheries is threatening many marine species. Here we examine the joint effects of increased mortality caused by shrimp trawling bycatch, and reduced predation caused by losses of large sharks because of longline fishing. Research surveys in the Gulf of Mexico (1972–2002) demonstrated precipitous declines in shallow water coastal elasmobranchs where shrimping...

Current methods and theory used in the study of the spatial dynamics of marine fish are problematic. Positive relationships between population abundance and occupied area are typically interpreted as evidence of density‐dependent habitat selection. However, both abundance and area may co‐vary with an un‐parameterized variable, such as a density‐independent effect. In addition, if density‐dependent habitat selection is present,...