MEPS prepress abstract   -  DOI: https://doi.org/10.3354/meps13603

ABSTRACT: The Northwest Atlantic (NWA) population of porbeagles Lamna nasus is susceptible to capture in rod-and-reel fisheries and most individuals are discarded alive due to catch and size limits. To estimate post-release survival, pop-off satellite archival tags were attached to 14 porbeagles captured with rod-and-reel, of which 13 tags transmitted. All sharks that reported data survived, giving a post-release survival rate of 100%. Following release, six individuals remained in surface waters, while two individuals immediately resumed normal diving behaviors. For the remaining sharks (n = 5), low tag transmission resolution precluded the detection of fine-scale post-release behavior. The duration of initial depth-holding behavior was characterized using a break-point analysis of dive track variance, which suggests porbeagles exhibited a median post-release recovery period of 116 h (10th and 90th percentiles = 68.8 and 280.1 h) following capture and handling. Our preliminary study suggests immature porbeagles are resilient to capture and handling, although more data would allow better support to management recommendations.