Distribution of angel sharks (Squatinidae) in United States waters of the western North Atlantic Ocean

Abstract

The distributions of sharks inhabiting deepwater ecosystems (>200 m) remain largely speculative because of limited collection efforts for species of relatively low commercial value and because of difficulties associated with sampling in deepwater habitats. As a result, ranges of deepwater shark species are often considered continuous across broad expanses despite records of occurrence, in many cases, being spatially fragmented. Within United States (US) waters of the western North Atlantic Ocean (WNA), the range of angel sharks (Squatinidae) in continental shelf and slope waters has been variously reported as both continuous and disjunct. The objective of this study was to use fishery-independent data to describe the range of angel sharks in US waters of the WNA and identify potential spatial discontinuities that could be consistent with the idea of multiple species or populations in the region. Results indicate that angel sharks in US waters of the WNA have a disjunct distribution and discontinuities occur from approximately Georgia through southern Florida and within a well-defined area off the coast of Louisiana. Evidence suggests spatial discontinuities could be related to thermal, salinity or current velocity barriers, or to a combination of these factors.