Essential habitat requirements and site fidelity of sandtiger sharks Carcharias taurus in Delaware Bay

Worldwide populations of the sandtiger shark (Carcharias taurus) have declined dramatically over the past several decades as a result of high rates of harvest in commercial and recreational fisheries.  Populations along the US East coast may have decreased by as much as 80% over this time period and sandtiger sharks have been grouped among the “prohibited species” category in the NMFS FMP for Atlantic Tunas, Billfish and Sharks.  Sandtiger sharks are of particular concern because they give birth to only two offspring every other year and thus have a reproductive output that rivals the lowest among any species of elasmobranch in the world.  Despite this high level of protection, there is very little information upon which to base assessment of sandtiger shark stocks and for monitoring progress of stock recovery.  Additionally, there is a paucity of information on basic aspects of the life history of sandbar sharks in US waters, including details of their migrations, seasonal use of large bays and essential habitat. 

Location of acoustic receivers and relative number of detections of sandtiger sharks on each receiver in Delaware Bay