Mortality due to fisheries interactions has been implicated as a contributor to population decline for several species of sea turtle. The incidental capture of sea turtles in the coastal gillnet fisheries of North Carolina, USA, has received much attention in recent years, and mitigation measures to reduce sea turtle mortality due to gillnet entanglement are a high priority for managers and conservationists. Efforts to evaluate effects of gillnet entanglement on sea turtle populations are complicated by the lack of information on health status of turtles released alive from nets and postrelease mortality. We obtained blood samples from green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempii) sea turtles captured in gillnets for 20–240 minutes to assess the impacts of gillnet entanglement on blood biochemistry and physiological status. We measured concentrations of lactate, corticosterone, ions (Na+, K+, Cl‐, P, Ca2+), enzymes (lactate dehydrogenase [LDH], creatine phosphokinase [CPK], aspartate aminotransferase [AST]), protein, and glucose in the blood and also performed physical examinations of turtles to document external indicators of health status (injuries, lethargy, muted reflexes). We evaluated the effects of entanglement time on blood biochemistry and to look for correlations between blood biochemistry and results of the physical examinations. We observed a significant increase in blood lactate, LDH, CPK, phosphorus, and glucose with increased entanglement time. Alterations in blood biochemistry were generally associated with a decline in health status as indicated by results of the physical examination. Although entanglement time plays an important role in determining the health status of sea turtles upon release from a gillnet, our results suggest that factors such as the depth and severity of entanglement may also have an effect on health status of turtles and the probability of postrelease survival. We were unable to set a maximum unattended gillnet soak time to minimize impacts on captured sea turtles, and therefore recommend that fisheries managers continue to enforce the net attendance regulations currently in place in the lower Cape Fear River, North Carolina, during the summer months.

North Carolina coastal waters are an important seasonal foraging habitat for juvenile green Chelonia mydas and Kemp's ridley Lepidochelys kempii sea turtles. Sea turtle mortality due to incidental capture in gillnets is a topic of great concern in this region, and fisheries regulations have been implemented to minimize sea turtle bycatch. Current regulations are based on estimates of fisheries-related sea turtle mortality derived from analyses of fishing effort, observed bycatch, and strandings data. Information regarding the health status of sea turtles at the time of release and documentation of post-release mortality are necessary in order to refine the mortality estimates used to govern management decisions. The primary goals of the present study were to use satellite telemetry to monitor post-release movements of sea turtles released from gillnets, document post-release mortality, and evaluate the feasibility and reliability of using blood biochemistry data collected at the time of capture to predict post-release mortality. Satellite telemeters were deployed on, and blood samples were collected from, juvenile green and Kemp's ridley sea turtles released from a 14 cm mesh gillnet set in shallow waters (1 to 5 m deep) in the lower Cape Fear River, North Carolina, USA. Twelve of 14 turtles released from the gillnet stayed in the lower Cape Fear River throughout the post-release tracking duration. We documented 1 confirmed and 3 suspected post-release mortalities. Blood chemistry analyses revealed differences in plasma ion (K + , Cl -, Na + ) and lactate levels between the turtle that died (confirmed mortality) and all other study animals, suggesting that these variables could serve as chemical predictors of post-release mortality. KEY WORDS: Lepidochelys kempii · Chelonia mydas · Satellite telemetry · Blood chemistry · FisheriesResale or republication not permitted without written consent of the publisher OPEN PEN ACCESS CCESS