Padrões sanguíneos e indicadores de estresse em tartarugas verdes juvenis

Abstract

Fisheries is one of the main threats faced by sea turtles. However, literature relating the physiological effects of incidental capture by fishing gears is scarce. The aim of this study is to establish blood reference values for a juvenile population of Chelonia mydas and compare them with animals incidental captured by fisheries in the same area, taking account seasonal variation. Blood was collected from 96 healthy green sea turtles, during summer and winter, by three different methods (dive, pound net and gillnet). Blood samples were analyzed for glucose, lactate, total protein, uric acid, albumin, total lipids, triglycerides, VLDL cholesterol, total cholesterol and corticosterone concentrations. Turtles captured in summer had a significant increase in blood glucose, total protein, uric acid and albumin, and a decreased in total lipids compared with turtles captured in winter. Although pound net is a passive capture mechanism, six of ten parameters differed significantly from base-line values established for the species. Entanglement in gillnets caused greater perturbations than pound net and all parameters analyzed were significantly different from the values obtained for animals captured by diving (reference values). These data indicate that incidental capture causes significant physiological disturbance in sea turtles and the results obtained in this study are important to help in the rehabilitation of turtles after capture. Reference values can be used for future comparisons with populations of the same species and with unhealthy and stressed individuals.