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Two students from Carleton University in Ottawa, Felicia St-Louis and Petra Szekeres, will be on The Island School campus until June 19th collecting data for their research on the thermal biology of the checkered puffer fish (Sphoeroides estudineus) and bonefish (Albula vulpes). Over her short visit this past February, Felicia was able to validate intra-muscular cortisol injections as a method of increasing blood cortisol (i.e. a stress hormone) to ecologically relevant levels in the checkered puffer for her MSc project. She is examining the effects of short-term cortisol elevation on the thermal biology of the puffers in the lab as well as in the field. By building a thermal profile of Page creek and releasing puffers tagged with thermal logging iButtons within the creek for a one month period, she will be able to compare habitat preferences between control and cortisol-dosed puffers. Determining the effects of additional environmental challenges such as temperature, on the physiology and behaviour of animals is relevant to understanding the thresholds for survival and predicting the associated ecological consequences. Felicia expects to shed some light on the physiological, behavioural and ecological effects of environmental change on coastal marine wildlife. Petra’s undergraduate research stems from the Florida cold snap of 2010 that resulted in over a million dead game fish including tarpon, snook and bonefish. The sublethal physiological and behavioural effects of the cold shock on bonefish were unknown. She is therefore, evaluating the consequences of a short term cold shock on bonefish. The physiological aspect of her study consists of taking a small blood sample, which will be analyzed for cortisol, lactate and glucose concentrations, pH and hematocrit. The behavioural aspect of her study consists of simulating response to a predation event as characterized by the distance they swim and the time it takes to exhaust the fish. This project hopes to achieve a framework for the sublethal consequences of cold shock in bonefish with regard to their stress levels and predator avoidance behaviour.
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