Research team

Sharks in distress: a comparative, ecophysiological, and behavioural approach toward quantifying the effects of chronic stress in sharks. 01/11/2023 - 31/10/2025

Abstract

Decades of overexploitation and habitat degradation have profoundly impacted sharks, leaving a third of all species threatened with extinction. To effectively guide and improve conservation efforts, a profound knowledge on the physiology, ecology and behaviour of sharks is urgently needed. A key research gap that requires particular attention are the effects of anthropogenic and environmental stressors on these ancient fishes. However, finding biomarkers of chronic stress in sharks has proven to be a challenging task due to their unique stress hormone, 1?-hydroxycorticosterone (1?-OHB). In the proposed research project, because the role of 1?-OHB in sharks remains equivocal, I will experimentally determine the utility of 1?-OHB as an indicator for chronic stress and unravel the metabolic action of 1?-OHB and its metabolites. Using state-of-the-art metabolomics, I intend to map the complete metabolic profile of sharks for the first time to identify novel biomarkers to be added to the physiology toolbox for shark conservation. A special emphasis will be put on ketone bodies and amino acids (on which sharks rely heavily for as oxidative fuels) and thyroid hormones, as well as the fitness cost of chronic stress. By studying the stress response from a cellular and molecular level (e.g., blood chemistry, metabolites) up to the whole-organism level (e.g., aerobic performance, behaviour) this project will provide a novel and broad view of the effects of chronic stress in sharks.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project

Chronic stress in sharks and their relatives: a comparative and ecophysiological approach to finding a biomarker of long-term stress. 01/11/2022 - 31/10/2023

Abstract

Decades of overexploitation and habitat degradation have profoundly impacted sharks and their relatives, leaving 37.5% of all species threatened with extinction. In order to effectively guide and improve conservation efforts, a profound knowledge on the behaviour, ecology, and physiology of elasmobranchs is urgently needed. A key research gap that requires particular attention are the effects of anthropogenic and environmental stressors on these ancient fishes. However, finding biomarkers of chronic stress in sharks and their relatives has proven to be a challenging task due to their unique stress hormone, 1?-hydroxycorticosterone (1?-OHB). In the proposed research project, because the role of 1?-OHB in elasmobranch fishes remains equivocal, I will experimentally determine the utility of 1?-OHB as an indicator for chronic stress in sharks and their relatives, and I will investigate and physiologically and biologically validate the use of elasmobranch teeth as a unique and novel biomarker of long-term stress. Additionally, the metabolic action and energetic cost of chronic stress on these fishes will be evaluated, with a special emphasis on ketone bodies and amino acids, as these can lead to a suite of possible biomarkers to be added to the conservation physiology toolbox for elasmobranch physiology.

Researcher(s)

Research team(s)

Project type(s)

  • Research Project