Direct effects of plankton size are stronger than abiotic factors in driving variation in fish life history traits
Year: 2026
Type: article
Abstract: Climate change is exerting multiple and pervasive effects on marine ecosystems, including alterations in environmental conditions, declines in ocean productivity, and modifications in trophic structure. Climate-induced changes have also been suggested to affect fish life history traits. So far, multispecies assessments addressing the propagation of climate effects through food webs remain scarce. Using the individual-based ecosystem model OSMOSE, including temperature and oxygen-dependent bioenergetics and eco-genetic sub-models, we simulated three major climate-induced drivers based on historically observed trends: increased sea surface temperature (SST), reduced oxygen saturation, and a decline in mean plankton size. We assessed their effects on species biomass and on gonad weight, size-at-age and age-at-maturation. The model was parameterized and fitted to the Bay of Biscay ecosystem dynamics over the period 2000-2022. Our results indicate that recent SST increases and oxygen declines had limited direct physiological impacts on biomass and life history traits. In contrast, recent reduction in mean plankton size emerged as the main vector of change. These alterations directly affected small pelagic fish and propagated through the food web, leading to a reduction in ecosystem carrying capacity and widespread modifications of life history traits. Overall, our findings highlight the central role of plankton size structure in climate-induced response of fish life history traits. These changes should be better considered in management frameworks, as they may affect the resilience of future fish population and ecosystem dynamics.
Source: Progress In Oceanography
Language: English
Subfield: Aquatic Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,720
OpenAlex ID: W7222819168