Nestor E. Bosch1,2, Albert Pessarrodona1, Karen Filbee-Dexter1 , Thomas Wernberg1
1University of Western Australia, Australia - 2Universidad de Las Palmas de Gran Canaria, Spain
Biodiversity plays a central role in the functioning of natural ecosystems, supporting ecological processes that underpin energy fluxes and, ultimately, scaling-up onto critical ecosystem services that sustain the welfare of human societies. As climate warms, the biodiversity of temperate reef ecosystems is rapidly being reshaped, with changes in diversity and structure of foundational kelp forests and associated species. While these patterns are well-documented and relatively understood, a mechanistic, process-based, understanding of how changes in community structure scale-up to shape important ecosystem dynamics is lacking. Here, we used Australia´s ‘Great Southern reef’ (GSR), a global biodiversity hotspot conformed of an interconnected kelp forest ecosystem, spanning > 8,000 km of temperate Australia and contributing at least AUD$ 10 billion year-1, to test the role of biodiversity change in three key functions mediated by reef fishes: (i) standing stock biomass (i.e., biomass, kg m-2), biomass production per unit of time (i.e., productivity, kg m-2 year-1), and proportion of biomass replenish per unit of time (i.e., turnover % year-1). We combined spatiotemporally comprehensive datasets on fish assemblages and habitat structure, covering > 1,500 sites from 1992 to 2024 across the entirety of the GSR, and climatic layers to uncover the relative role of biodiversity, habitat, and environmental changes in mediating spatial and temporal changes in fish ecosystem functions. Then, we explored how changes in these process-based metrics scale-up into the productivity potentially harvested (i.e., targeted species biomass and productivity) by recreational and professional fishers in the region. Our study represents an important step to link diversity change with ecosystem productivity, which is key to fine-tune management and conservation actions that aim to maintain the functioning of temperate marine ecosystems under future warming scenarios
Biography
Nestor E. Bosch is a post-doctoral researcher at Universidad de Las Palmas de Gran Canaria. His research focuses on understanding the mechanisms underpinning variation in the diversity and assemblage structure of reef fish communities across spatial and temporal scales, with a major focus on using trait-based approaches to understand how climate and other anthropogenic stressors modify key functions provided by reef fishes in coastal ecosystems.