2023 . Article in a Journal

Daniel van Denderen, Aurore A. Maureaud, Ken H. Andersen, Sarah Gaichas, Martin Lindegren, Colleen M. Petrik, Charles A. Stock, Jeremy Collie

Demersal fish biomass declines with temperature across productive shelf seas

in: Global Ecology and Biogeography . Volume 32, Issue 10

Abstract

Major Taxa Studied

Marine teleost fish and elasmobranchs.

Methods

We compiled high-resolution bottom trawl survey data of fish biomass containing 166,000 unique tows and corrected biomass for differences in sampling area and trawl gear catchability. We examined whether relationships between net primary production and demersal fish community biomass are mediated by temperature, food-web structure and the level of fishing exploitation, as well as the choice of spatial scale of the analysis. Subsequently, we examined if temperature explains regional changes in fish biomass over time under recent warming.

Results

We find that biomass per km2 varies 40-fold across regions and is highest in cold waters and areas with low fishing exploitation. We find no evidence that temperature change has impacted biomass within marine regions over the time period considered. The biomass variation is best explained by an elementary trophodynamic model that accounts for temperature-dependent trophic efficiency.

Main Conclusions

Our study supports the hypothesis that temperature is a main driver of large-scale cross-regional variation in fish community biomass. The cross-regional pattern suggests that long-term impacts of warming will be negative on biomass. These results provide an empirical basis for predicting future changes in fish community biomass and its associated services for human wellbeing that is food provisioning, under global climate change.