Process-based metrics inform sustainable marine management after a catastrophic natural event

Abstract

Understanding temporal dynamics in ecological communities is key to develop management plans that target sustainability. Process-based metrics quantify dynamic properties of ecological communities, and thereof have been recently advocated as a promising tool to guide management strategies. To date, however, their empirical application has been limited, hindering their utility to inform conservation planning in response to a range of natural and human-driven disturbances. Here, we compare the succession of fish communities after a catastrophic natural event, a volcanic eruption and the formation of nascent reefs, through the lens of complementary static (species richness, abundance, and biomass) and process-based (productivity and turnover) metrics. We found markedly contrasting dynamics between these metrics, particularly when looking at fish biomass and productivity. During incipient stages of community development, fish productivity increased exponentially, whereas the recovery of fish biomass considerably lagged behind, underscoring high rates of biomass replacement (i.e., turnover) in the system. This buffering response (higher production per unit of biomass) was best predicted by average community body size, highlighting the role of compensatory ecological mechanisms during primary ecological succession. Traits related to resource acquisition, particularly the harnessing of planktonic energy subsidies, further enhanced predicted fish biomass and productivity at local scales. This study therefore supports the burgeoning call to inform conservation and management planning through complementary metrics that give a nuanced understanding on ecosystem functioning.