Conclusion
To anticipate the consequences of climate change on marine ecosystem
function and services (e.g., food provisioning and climate regulation
through carbon sequestration) it is critical to understand how changes
in ocean productivity and temperature may affect the upper trophic
levels of marine ecosystems. Our large-scale empirical investigation
showed a pronounced latitudinal increase in demersal fish community
biomass from the subtropics to the poles. The changes in demersal
community biomass are linked to differences in temperature, fishing, and
ocean productivity. The observed negative relationship between
temperature and community biomass indicates that the long-term impacts
of climate warming on community biomass will be negative. This finding
is consistent with model predictions of fish biomass (Lotze et
al. 2019; Tittensor et al. 2021). Hence, our results provide an
important empirical basis to formally validate and ground truth such
model-based predictions in order to evaluate sound and robust management
actions in the face of global change.