Fishing and Warming Reshape Size Spectra of Commercial Species in the Mediterranean Sea

Anthropogenic pressures, particularly fishing effort and ocean warming are reshaping marine ecosystems and influencing the population dynamics of key fisheries species. While these stressors have been widely studied in isolation, their interactive effects across taxonomically distinct groups remain poorly understood. Here, we examine how fishing pressure and increasing temperature jointly affect the size spectra of nine commercial species (three bony fish, three crustaceans, and three cephalopods) in the central Mediterranean Sea. Using size-spectrum analyses applied to fishery-independent survey data from 2000 to 2023, we evaluate population-level responses to these stressors. Our findings reveal taxon-specific patterns: under high fishing effort and high temperatures, fish populations exhibit a higher proportion of smaller individuals, consistent with fishing-induced truncation and temperature-driven metabolic constraints. In contrast, crustaceans and cephalopods show different responses, reflecting their greater physiological plasticity and shorter life cycles, which may buffer against environmental changes. These results suggest that the combined effects of fishing and climate change could disproportionately reduce fish biomass while allowing more flexible taxa to persist or even thrive. Our results emphasize the need for adaptive management strategies that incorporate both environmental change and fishing pressure projections to maintain sustainable yields and ecosystem resilience in the face of ongoing climate-driven shifts.