The importance of temperature in determining where different fish species are found is demonstrated through investigations from southern Portugal to northern Norway.
As a result of the study’s confirmation that temperature is a major factor in large-scale geographic variation in fish communities, it is now possible to use climate projections to determine where specific species will be most prevalent by 2050 and 2100. The findings show that, in general, regions with more warming, they are projected to have the largest changes at the community level, with the effects more pronounced further north – at higher latitudes.
The study was the first of its kind to use data from fisheries surveys over such a wide area to assess how environmental variation drives species distribution. The study included 198 marine fish species from 23 surveys and 31,502 samples collected by fisheries scientists between 2005 and 2018.
Martin Genner, Professor of Evolutionary Ecology at the University of Bristol’s Faculty of Life Sciences, who led the research, said: “This unique study brings together fisheries survey data from across this vital marine ecosystem. Using this information, we are able to convincingly demonstrate the broad importance of sea temperature in controlling how fish communities assemble.
Louise Rutterford, lead author of the study, which was carried out at both the Universities of Bristol and Exeter, said: “The team’s analysis showed how temperature emerged as the most critical variable for determining where species were found, with water depth and salinity also being important factors. This allowed us to use predictive models to learn more about how fish will respond to a warming climate in the coming decades.
Professor Steve Simpson, who oversaw the research, added: “The study adds to a growing body of evidence suggesting that future climate-induced warming will lead to large-scale changes in fish communities, which may result in changes in commercial fisheries catches across the region.” .”
