Ecosystem accessibility, through road networks, is the main driver of their conditions, with the most accessible ecosystems being most at risk of resource depletion. To date, measuring accessibility to humans was strictly limited to examining the linear distance which ignores ragged coastlines and road networks that can affect the time required to reach fishing grounds. With a focus on coral reefs, this research presents a double challenge: (i) developing new metrics of accessibility that account for seascape heterogeneity to better assess human impacts on coral reefs; (ii) evaluating the importance of coral reef accessibility, in interactions with their management, to explain variations of fish biomass. First, I propose novel metrics of reef proximity to human populations and markets based on the friction distance which is related to transport surfaces (paved road, dirt road, water) influencing the effective reach of human settlements. Second, I use three applications to highlight the importance of these new metrics. Specifically, I addressed the following questions: (1) how local human communities and market jointly affect the conditions of coral reefs at local scale? (2) how human impacts affects reef fish biomass in interaction with management?, and (3) how identify key species associated to fish biomass given human pressure? Within the context of global changes and biodiversity loss, this research challenges the sustainable and efficient management of coral reef socioecological systems with accessibility being the cornerstone.
Eva is a cotutelle PhD Candidate at James Cook University (ARC CoE for Coral Reef Studies) and University of Montpellier (MARBEC lab, France). An engineer in life sciences by training, Eva acquired a solid grounding to identify challenges and propose solutions in ecosystem management and conservation. She decided to nourish her fascination for marine ecosystems by completing her Master’s degree working on a global-scale assessment of coral reefs accessibility which inspired her to start a PhD on the same topic. For her thesis, she is examining the social and ecological drivers of fish biomass on coral reefs under the supervision of Professors David Mouillot and Joshua Cinner, Dr Andrew Hoey and Prof Catherine Aliaume.