Plasma chemistry and hematology of Eastern Mediterranean Sea green turtles undergoing rehabilitation

The Eastern Mediterranean Sea (EMS) is oligotrophic, presenting low biological production and high temperature and salinity, while comprising a biodiversity hotspot, with a unique emblematic threatened species array, including sea turtles. The establishment of healthy captive green turtle (Chelonia mydas) baseline blood analyte reference intervals (RIs) will contribute to improving diagnosis, treatment, rehabilitation and conservation success rates for sea turtles, by offering information with therapeutic and prognostic implications. However, baseline plasma chemistry and hematological analytes of EMS C. mydas are still unavailable. Hence, this study aimed to establish RIs for several blood analytes in general and under different life and rehabilitation stages and compare results with congeneric and conspecifics of other regions: Mediterranean loggerhead turtles (Caretta caretta) and two Atlantic green turtle populations. The study engulfed 118 blood samples obtained from 72 turtles admitted to the Israel Sea Turtle Rescue Centre between 2008 and 2020. Blood analyses included plasma chemistry and packed cell volume (PCV), and their association with body size and health status, and enabled suggesting RIs for PCV, plasma glucose and potassium concentrations, and aspartate transaminase and alkaline phosphatase activities. The PCV were significantly associated with rehabilitation. Noted differences arising via population comparison are likely associated with interspecific dietary and metabolic traits. These novel physiological results form the basis for future studies, and provide caregivers a tool potentially increasing the success of recovery, rehabilitation and conservation efforts. Further research is warranted to fill knowledge gaps concerning physiology and potential ecological impacts on this species.