Project support provided by the NOAA Bycatch Reduction Engineering Program
|Collaborative Researchers:||Diego Bernal, Ph.D. (University of Massachusetts)
Craig Heberer, NOAA Southwest Region
Suzy Kohin, Ph.D., NOAA SWFSC
This project uses PSAT technology to estimate survivorship in three different components of the Southern California recreational fishery for thresher sharks. Initial work started off with quantifying catch and release mortality in the caudal-based (tail-hook) fishery. This Fishery usually targets larger thresher sharks by trolling lures with j-hooks. When the shark makes its initial strike with its tail, the shark gets hooked and is fought and brought to the boat by the tail. This work identified relatively high mortality rates for the sharks that were on the line for periods in excess of 85 minutes (Hebberer et al., 2010). At times, this foul-hooking strategy represents the largest component of the recreational fishery. Recommendations from this work have been presented at over a dozen public venues and assisted in the production of a NOAA and PIER endorsed brochure on best fishing practices.
The second and third phases of this work are currently underway and focus on additional modes of capture as well as issues that surround the recreational fishery. Because several different techniques are used to catch threshers and not all threshers are hooked in the tail, the team of collaborators have focused on assessing catch and release mortality using mouth-hooking techniques as well as studying the effects of trailing gear (lures left embedded in the caudal fin of sharks that are lost during the fight). These studies are currently in the data collection phase .
Read more about other ongoing thresher shark studies at PIER