Campbell, M. D., Patino, R., Tolan, J., Strauss, R., and Diamond, S. L. 2010. Sublethal effects of catch-and-release fishing: measuring capture stress, fish impairment, and predation risk using a condition index. – ICES Journal of Marine Science, 67: 513–521. The sublethal effects of simulated capture of red snapper (Lutjanus campechanus) were analysed using physiological responses, condition indexing, and performance variables. Simulated catch-and-release fishing included combinations of depth of capture and thermocline exposure reflective of environmental conditions experienced in the Gulf of Mexico. Frequency of occurrence of barotrauma and lack of reflex response exhibited considerable individual variation. When combined into a single condition or impairment index, individual variation was reduced, and impairment showed significant increases as depth increased and with the addition of thermocline exposure. Performance variables, such as burst swimming speed (BSS) and simulated predator approach distance (AD), were also significantly different by depth. BSSs and predator ADs decreased with increasing depth, were lowest immediately after release, and were affected for up to 15 min, with longer recovery times required as depth increased. The impairment score developed was positively correlated with cortisol concentration and negatively correlated with both BSS and simulated predator AD. The impairment index proved to be an efficient method to estimate the overall impairment of red snapper in the laboratory simulations of capture and shows promise for use in field conditions, to estimate release mortality and vulnerability to predation.

Red Snapper Lutjanus campechanus is the most economically important reef fish in the Gulf of Mexico, and despite being intensively managed, the stock remains overfished. These fish are susceptible to pressure‐related injuries (i.e., barotrauma) during fishing that compromise survival after catch and release. Barotrauma‐afflicted fish may not only experience immediate mortality but also delayed mortality after returning to depth. This variability and unknown fate leads to uncertainty in stock assessment models and rebuilding plans. To generate better estimates of immediate and delayed mortality and postrelease behavior, Red Snapper were tagged with ultrasonic acoustic transmitters fitted with acceleration and depth sensors. Unique behavior profiles were generated for each fish using these sensor data that allowed the classification of survival and delayed mortality events. Using this information, we compared the survival of Red Snapper released using venting, nonventing, and descending treatments over three seasons and two depths. Red Snapper survival was highest at cooler temperatures and shallower depths. Fish released using venting and descender tools had similar survival, and both these groups of fish had higher survival than nonvented surface‐released fish. Overall, Red Snapper had 72% survival, 15% immediate mortality, and 13% delayed mortality, and all fish suffering from delayed mortality perished within a 72‐h period after release. Results from these field studies enhance the understanding of the delayed mortality and postrelease fate of Red Snapper regulatory discards. Moreover, these data support the practice of using venting or descender devices to increase the survival of discarded Red Snapper in the recreational fishery and show that acoustic telemetry can be a valuable tool in estimating delayed mortality. Received March 6, 2015; accepted July 15, 2015

The most controversial fishery in U.S. waters of the Gulf of Mexico (Gulf) is for northern red snapper Lutjanus campechanus, which collapsed in the late 1980s when stock biomass became too low to be fished commercially in the eastern Gulf. 123Rev Fish Biol Fisheries (2011) 21:187-204 DOI 10.1007 of red snapper in the Gulf, which in turn has strained the relationship between science, management, and stakeholders there. We provide a simple empirical argument and alternate interpretations of a recently published perspective on the historical fishery of red snapper in the Gulf to conclude that the preponderance of evidence used in the agency stock assessment process, and the simple arguments made here, do not support the perspective that the red snapper stock has increased in size sufficiently to defer compliance with the MSRA.

Red Snapper Lutjanus campechanus are the most economically important reef fish in the Gulf of Mexico and a heavily targeted fishery. When brought to the surface from deep water, this species often suffers pressure‐related injuries collectively known as barotrauma. This trauma results in high discard mortality and has affected recovery of the fishery. In laboratory experiments using hyperbaric chambers, we assessed sublethal effects of barotrauma and subsequent survival rates of Red Snapper after capture events from pressures corresponding to 30 and 60 m deep. We then evaluated the use of rapid recompression and venting to increase survival and improve recovery after release in this controlled environment. Vented fish in simulated surface release and rapid‐recompression treatments had 100% survival. Fish released at the surface that were not vented had 67% survival after decompression from 30 m but only 17% survival from 60 m, while nonvented rapidly recompressed fish had 100% survival from 30 m and 83% survival from 60 m. Fish that were vented upon release at the surface showed significantly better ability to achieve an upright orientation and evade a simulated predator. Results showed clear benefits of venting or recompression. Our data also show strong depth effects resulting in increased barotrauma injuries, more impaired reflexes, and greater mortality as depth increases. Overall, our data support venting or rapid recompression as effective tools for alleviating barotrauma symptoms, improving predator evasion, and increasing overall survival. Received January 31, 2014; accepted April 7, 2014