Effects of Air Exposure on Postrelease Mortality Rates of White Marlin Caught in the U.S. Offshore Recreational Fishery

Abstract

White Marlin Kajikia albida are targeted by recreational fisheries in tropical and subtropical waters of the Atlantic Ocean. Off the U.S. East Coast, the vast majority of White Marlin are released after capture. Federal regulations prohibit anglers from removing a White Marlin from the water unless the fish is to be retained; however, numerous photographs of anglers holding White Marlin out of the water are posted on the Internet each summer, demonstrating that there is considerable noncompliance with this management measure. To better understand the effect of air exposure on postrelease survival of White Marlin, we attached pop‐up satellite archival tags (PSATs; programmed to release after 30 d) to individuals that were caught on natural baits rigged with circle hooks and that were removed from the water for a period of 1 min (n = 6 fish), 3 min (n = 5 fish), or 5 min (n = 7 fish). We compared our results with those from a previous study in which PSATs were used to follow the fates of 59 White Marlin that were caught on circle hooks but not removed from the water. The proportion of postrelease mortalities increased with air exposure duration; the overall rate of postrelease mortality was significantly higher for White Marlin that were subjected to air exposure (33.3%) than for those that remained in the water (1.7%). These data provide strong support for the current U.S. regulation prohibiting the removal of a White Marlin from the water if the fish is to be released. Effective communication of the deleterious effects of air exposure on White Marlin should help to deter the practice of removing fish from the water among members of the recreational angling community, which has been supportive of other conservation measures for this species.Received January 13, 2016; accepted June 15, 2016 Published online September 30, 2016

Meta‐analysis of post‐release fishing mortality in apex predatory pelagic sharks and white marlin

“…Though Graves et al. () analysed F r data from several studies, they did not synthesize precise F r rates nor did they account for between‐study variability. Musyl et al.…”

“…() delimited survival outcomes for tail‐hooked threshers and it is apparent survival could be enhanced by heavier pound test lines in recreational gear to reduce fight times. Catch and rapid release of white marlin, limiting air exposure times to <1 min (Graves et al., ; Schlenker et al., ) was shown to reduce mortality by ~3% in the sensitivity analysis. Since pelagic sharks are obligate ram‐ventilators, captured sharks could benefit from longer gangions that might allow for extra movement (Gallagher, Orbesen, Hammerschlag & Serafy, ). Adding a section of shock cord near longline clips (i.e.…”

“…For fisheries management and conservation, having precise survival rates of discards and at‐vessel mortality rates are necessary to advance and justify non‐retention, catch‐and‐release policies (Ellis, Phillips & Poisson, ; Graves, Marcek & Goldsmith, ; Moyes et al., ; Pine, Martell, Jensen, Walters & Kitchell, ) and other by‐catch mitigation strategies to rebuild stocks (Carruthers, Schneider & Neilson, ; Dapp, Huveneers, Walker, Drew & Reina, ; Favaro & Côté, ; Gilman et al., ; Poisson et al., ; Uhlmann et al., ). In fisheries population biology, it is necessary to account for the two main sources of fishing mortality: at‐vessel or catch (i.e.…”

“…By compiling and synthesizing effect sizes across multiple independent studies and fisheries, the pooled F r estimates presented herein are the best and most precise available for several species of pelagic sharks and white marlin. White marlin were included in the study for several reasons, including (a) concerns about their stock status (Graves et al., ; Schlenker et al., ), (b) demonstrating the utility meta‐analyses and (c) comparing the robustness of apex predatory pelagic species to the effects of fishing. Moreover, to validate the efficacy and usefulness of the technique and to increase precision in point estimates, the current meta‐analysis demonstrates the ability to act like a “living document” in that addition of new studies increased precision in earlier meta‐analyses on F r rates for blue shark and white marlin.…”

Effects of Air Exposure During Simulated Catch‐and‐Release Angling on Survival and Fitness of Yellowstone Cutthroat Trout

“…White Marlin Kajikia albida captured via angling off the coast of Virginia Beach, Virginia, had a mortality rate of 17% when exposed to air for 1 min (Graves et al. ). Mortality of White Marlin exposed to air for 5 min increased to 43%.…”