Shifting fish distributions in warming sub-Arctic oceans

Area of Science:

• Marine Biology
• Climate Change Ecology
• Fisheries Science

Background:

• Marine fish exhibit distinct responses to climate warming compared to terrestrial homeotherms due to direct thermal effects and habitat.
• Sub-Arctic waters around Iceland are highly productive ecosystems sensitive to environmental changes.

Purpose of the Study:

• To quantify three-dimensional distribution shifts of marine fish species in response to climate warming.
• To identify factors influencing fish distribution changes, including temperature and species abundance.

Main Methods:

• Utilized linear models and graphical tools to analyze data from 5390 standardized groundfish survey tows over 22 years.
• Examined the distribution shifts of 82 fish species in relation to temperature and abundance variations.

Main Results:

• A 1°C temperature increase significantly altered the distribution of 72% of fish species, primarily shifting northwestward.
• Species abundance changes influenced 62% of species but lacked a poleward orientation.
• Stenothermal species and those with limited ranges were most susceptible to distribution shifts; deepwater species were not.

Conclusions:

• Climate warming is driving significant distributional changes in marine fish populations in the sub-Arctic.
• A projected 2-3°C warming could lead to substantial alterations in sub-Arctic fisheries locations.
• Understanding these shifts is crucial for fisheries management and conservation efforts.