Physiological ramifications for loggerhead turtles captured in pelagic longlines.
Bycatch of endangered loggerhead turtles in longline fisheries results in high rates of post-release mortality that may negatively impact populations. The factors contributing to post-release mortality have not been well studied, but traumatic injuries and physiological disturbances experienced as a result of capture are thought to play a role. The goal of our study was to gauge the physiological status of loggerhead turtles immediately upon removal from longline gear in order to refine our understanding of the impacts of capture and the potential for post-release mortality. We analysed blood samples collected from longline- and hand-captured loggerhead turtles, and discovered that capture in longline gear results in blood loss, induction of the systemic stress response, and a moderate increase in lactate. The method by which turtles are landed and released, particularly if released with the hook or line still attached, may exacerbate stress and lead to chronic injuries, sublethal effects or delayed mortality. Our study is the first, to the best of our knowledge, to document the physiological impacts of capture in longline gear, and our findings underscore the importance of best practices gear removal to promote post-release survival in longline-captured turtles.
Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403, USA williarda@uncw.edu.
Amanda
A
Williard
SUBMON, c/ Rabassa, 49-51, Barcelona 08024, Spain.
Mariluz
M
Parga
ALNITAK, Nalón 16, 28240 Hoyo de Manzanares, Madrid, Spain.
Ricardo
R
Sagarminaga
NOAA Pacific Islands Fisheries Science Center, 1845 Wasp Boulevard, Honolulu, HI 96818, USA.
Yonat
Y
Swimmer
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003247:Conservation of Natural Resources; D005398:Fisheries / Q000379:methods*; D006400:Hematocrit; D006854:Hydrocortisone / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D008522:Mediterranean Sea; D013312:Stress, Physiological; D014426:Turtles / Q000097:blood / Q000502:physiology*
D001786:Blood Glucose; D019344:Lactic Acid; D006854:Hydrocortisone
bycatch; corticosterone; delayed mortality; fisheries; lactate; physiology