Seas in a changing climate - can coastal fish cope?

Last changed: 17 April 2023
Cod on underwater meadow

Cod is a keystone species in marine ecosystems. It shapes the conditions for a large number of other species in the sea and is also of great importance both economically and culturally. However, the Swedish Atlantic cod stocks are on the verge of collapse with serious population declines observed in the Baltic Sea and on the Swedish west coast. Will the already weakened cod stocks meet another challenge; climate change? And how will climate change affect other coastal fish species?

Research based on the latest climate models shows that the temperature will rise and lead to local heat waves. Ocean acidification will increase, and salinity may be reduce. Together, these climate effects will dramatically alter the marine environment around Sweden.

Climate effects cause physiological stress

Each of these changes can cause physiological stress in marine organisms. In order to better understand the anticipated fate of cod in a changing climate, this project aims to investigate how Atlantic cod (Gadus morhua) and Goldsinny wrasse (Ctenolabrus rupestris) from coastal populations in the Baltic Sea and the North Sea respond to the cumulative effects of climate change factors such as reduced salinity (freshening), reduced pH (ocean acidification) and increased temperature (warming events).

The project is based on experimental studies where coastal fisheries-targeted fish, are kept in aquariums that simulate the various changes. The sensitivity of the fish is measured by physiological variables

Food and climate

Will future generations be able to eat cod? Here, Diana Hammar Perrytells about how climate change affects cod and about the project where she investigates how cod reacts to physiological stress.

Knowledge for climate-adapted management

The project results will provide detailed knowledge of the sensitivity of different populations of Atlantic cod and an indication of how they might respond to future climate change. This knowledge may, together with spatial projections of climate change effects, be a crucial means of climate readying the management strategies for cod in the future to ensure that the environment, anglers and the fishing industry can all continue to enjoy the fish for generations to come.


The research team consists of Diana Hammar Perry (SLU Aqua), Håkan Wennhage (SLU Aqua), Filip Svensson (SLU Aqua), Martin Gullström (Södertörn University), Albin Gräns (SLU) and Michael Axelsson (University of Gothenburg)


The project "Sensitivity of Swedish cod populations to global climate change stressors " is funded by the Swedish Environmental Protection Agency and is ongoing 2020-2024. 


Diana Hammar Perry, Environmental Monitoring and Assessment Analyst
Department of Aquatic Resources,  SLU, +46(0)10-478 40 97