The expansion of the world's fisheries and the decline in fish stocks have increased conflicts between humans and marine megafauna. These conflicts result from negative interactions that are either direct (bycatch and/or depredation on catches) or indirect (competition for resources). They have socio-economic costs for the human communities dependent on the fishing activity and they impact the survival of the megafauna species and the ecosystems involved. However, long-lasting solutions for coexistence between fisheries and marine megafauna, which require inter- and trans-disciplinary research to be identified, remain limited. Therefore, the aim of my PhD is to produce integrated knowledge that can help in identifying the conditions required for megafauna species conservation, the sustainability of exploited resources and the socio-economic viability of the fishing activity. Specifically, under a co-supervision combining social sciences and marine ecology, I will use the principles of Sustainability Science and a multi-site approach (longline fisheries - marine megafauna conflicts in the French Southern lands and in New Caledonia) i) to understand both the anthropogenic and ecological drivers and consequences of these conflicts, and ii) to examine new management approaches that can ensure the sustainability of the whole socio-ecosystems involved.

Managing conflicts between humans and marine predators is hampered by limited knowledge on the ecological and behavioural mechanisms leading species to interact with humans. Among these mechanisms, the drivers of variation in the propensity of individuals to take risks by approaching humans, including the role of personality traits, remain poorly understood. The killer whale is among the species most frequently involved in conflicts with humans in the marine environment, mainly through depredation on fishery catches, a behaviour that has been acquired by many populations of the world. From the case conflict associated with killer whales feeding on fisheries catches around the Crozet islands, the main objective of my PhD project is to examine how inter-individual heterogeneity in behaviours are associated with variation in personality traits, and to investigate how these traits contribute, among other factors, to the response of individuals to a human activity involving risks and how they influence population dynamics.

The socio-economic and ecological implications of depredation are especially strong in the Patagonian toothfish longline fisheries and the sub-Antarctic ecosystems they operate in. These fisheries have become the primary economic activity of sub Antarctic waters and vessels experience high levels of depredation by two large toothed whale species; killer whales and sperm whales.  The amount of fish these species remove from the fishing gear pose a real challenge for the assessment of targeted stocks, and the behaviour is known to impact depredating killer and sperm whale populations, which are subject to high conservation concerns. Together with the socio-economic costs depredation incurs to fishers and fishing companies, these impacts make the development of mitigation solutions a priority.  Therefore, my research project aims to minimize depredation in toothfish fisheries through investigating three  key research questions: 1)  Does the effect of toothed whale presence on the amount of toothfish caught significantly differ between fishing techniques? 2) At what distance and during which stages of fishing operations do toothed whales detect fishing vessels? 3) Where are toothed whales most likely to be encountered in fishing areas, given their prey preferences and the associated environmental conditions? 

I have been working on conspecific aggression in killer whales as part of my MSc at the University of Montpellier. The project involves using conspecific scars visible in photo-identification images as a proxy for physical interactions and aims to determine whether prey preferences and social structure influence scarring rates by comparing three distinct populations: the "Bigg's" and "Northern resident" killer whales in British Columbia, and the killer whales of the Crozet archipelago. It also considers whether demographic factors such as age and sex may influence physical interactions as well as how conspecific scars heal over time. The work is a collaboration between the UMR MARBEC (France) and Bay Cetology (Canada).