Endocrinology and Ecotoxicology: linking physiology and trophic ecology

This theme of research combines ecotoxicology, endocrinology, and stable isotope analysis to investigate how foraging ecology and pollutants impact the fitness of organisms.

My current project on southern elephant seals and examines the remobilization of adipose tissue during fasting events, which consequently amplifies pollutant concentrations that are incorporated into metabolically inert but continuously growing keratinous tissues. We are using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to construct a longitudinal (multi-month) record of pollutants for each individual seal. A goal of this research is to better understand how physiology and the timing of tissue sampling affect measured contaminant loads, which has important implications for biomonitoring programs. In addition, such information can be linked to organismal fitness. For example, the spike in pollutant concentrations observed in elephant seals while fasting coincides with blastocyst implantation and our preliminary data shows that pollutants cross the placenta barrier. Such information can also be combined with telemetry-based movement and isotope-based dietary data to provide insight on which habitats are sources of pollutants and how these compounds are biomagnified across trophic levels.

During my Ph.D., I developed a cutting-edge method to extract 32 different steroids from keratinous tissues using Ultra Performance Convergence Chromatography (UPC2) in collaboration with colleagues at Stellenbosch University (Lübcker et al. 2020a).

Collectively this work strives to understand how foraging variation, pollutants, and animal physiology interact to drive animal body condition and reproduction in animals.