The effects of barotrauma and deepwater-release mechanisms on the reproductive viability of yelloweye rockfish in Prince William Sound, Alaska

Abstract

Previous research has shown that releasing sport-caught Yelloweye Rockfish Sebastes ruberrimus with a deepwater-release mechanism (DRM) can alleviate anatomical damage due to barotrauma. However, it is unknown if a Yelloweye Rockfish remains a viable member of the population and reproduces in subsequent years following a barotrauma event and recompression with a DRM. The objectives of my study were to: 1) determine if Yelloweye Rockfish were able to reproduce one to two years following known forced decompression and recompression event(s); and 2) evaluate if barotrauma and recompression affected the quality of developing embryos. In 2010, Yelloweye Rockfish were sampled from an isolated reef in Prince William Sound, Alaska. Fifteen females tagged in 2008 and 2009 were recaptured in 2010, and reproductive status was identified by visual observation of the gonads and hematological sampling (i.e., vitellogenin and calcium²⁺ plasma concentrations). Oil globule volume, percent lipid, and caloric content were also measured for the embryos from seven of these females and these values were compared to embryos from 13 females with no previously documented barotrauma and recompression events. These results showed that all 15 Yelloweye Rockfish recaptured in 2010 were gravid (with eggs) or spent (having released eggs). In addition, there were no differences in median oil globule volume, caloric content, and percent lipid between individual embryos from new captures and recaptures. Results indicated that there is no evidence that reproduction and embryo quality of Yelloweye Rockfish is adversely affected one to two years following forced decompression and recompression with a DRM at the depths sampled in this study. This research provides information on the utility of DRMS as a tool for rockfish conservation and supports the importance of utilizing these devices by sport anglers.