Who Goes Where? Use of Multiple Tagging Approaches to Characterize the Behavior of Spiny Dogfish (Squalus acanthias) in the Northwest Atlantic

Recently a new hypothesis suggesting the possibility of multiple behavioral contingents of spiny dogfish (Squalus acanthias), was proposed by scientists from NOAA-NMFS, Fisheries and Oceans Canada, and East Carolina University (ECU); this hypothesis identified two behavioral contingents (a mid-Atlantic contingent and a Gulf of Maine contingent) that are susceptible to the spiny dogfish fishery.  The overall objective of this research is to increase understanding of migration and movement behaviors unique to the mid-Atlantic behavioral contingent of spiny dogfish.  Since 1996, East Carolina University has conducted a mark-recapture tagging program primarily targeting mid-Atlantic contingent spiny dogfish.  As of December 31, 2013, ECU has received approximately 619 tag returns out of over 47,000 tags released (1.32% return rate).  Given the low return rate of conventional external tags and the need for higher resolution data, ECU researchers deployed over 220 acoustic tags in spiny dogfish since 2009. Single redetection rates for acoustic tagging projects were much higher (ranging between 40 and 83 percent) and many of these tags were redetected multiple times on acoustic arrays between North Carolina and Maine.  These data are analyzed with fishery-dependent and fishery-independent research and data to address behavioral questions on multiple spatial and temporal scales.