Abstract:
Biomass is unevenly distributed across Earth, with some ecosystems producing and concentrating much more of it than others. On land, plants dominate, making up 95% of total biomass. In the ocean, however, most biomass consists of consumers, with prokaryotes, protists, and animals each contributing roughly equally. My research focuses on the latter group, aiming to understand how heterogeneity in animal biomass emerges within tropical coral reef communities and beyond. Animal biomass provides resources that sustain millions of people –largely through tropical fisheries– but that are increasingly under pressure from multifaceted global changes. In this talk, I will first introduce my prior research quantifying fish biomass production on coral reefs, from small to large spatial scales, and how this ecosystem function is affected by 1) habitat shifts triggered by catastrophic disturbances; 2) fishing and overfishing; and 3) ocean-reef connectivity providing substantial energy inputs to reef consumers. Then, I will present two studies recently developed in my Branco Weiss and PSL Junior fellowship project setting coral reef productivity in a broader context. The first evaluates the generality of the ‘coral reef paradox’, the idea that reefs are oases in ocean deserts, by quantifying how often desert-like conditions occur in global tropical oceans where reefs are found. It also explores Charles Darwin’s historical role in this context. The second study takes a comparative approach, compiling decades of data on animal biomass density across marine, estuarine, freshwater, and terrestrial ecosystems, asking: are coral reefs truly exceptional in terms of animal biomass?

Bio:
Affiliation: Branco Weiss and PSL Junior Fellow (postdoctoral), Université Paris Sciences et Lettres, EPHE-CRIOBE, Perpignan, France

After a PhD at James Cook University, in Australia, I moved in 2022 to PSL (based at CRIOBE-EPHE, in Perpignan) to work alongside Valeriano Parravicini on ecosystem functions on coral reefs and beyond. My research project explores the role of the surrounding seascape in shaping the productivity of tropical reefs, from quantifying the ‘energetic footprint’ of animal biomass, to determining links with non-reef habitats across the broader seascape, and the mechanisms that maintain these links. This research is guided by the principle that ecosystem productivity should be understood as the interaction of internal and external energetic pathways connecting photosynthesis to biomass production. The overarching goal is to develop predictive models relating environment and biomass production and, in the long term, to develop theory explaining the productivity of ecosystems more broadly.