An international research study has examined how the combined effect of climate change may affect tuna and swordfish productivity and size in the future.

The three-year study by technology centre AZTI, concludes that the tuna stocks analysed will decrease their global potential productivity by 36% by 2050, on average.

Yellowfin tuna

Source: AZTI

There are stocks including Pacific bluefin, yellowfin tuna (pictured) and Pacific skipjack tuna where, on the contrary, increases in size are projected.

In addition, body sizes are expected to decrease by 15% by 2050 and, consequently, also the demand, the price of fish and the revenues for the fishing industry.

“We wanted to know how the climate change and fishing pressure is going to impact some of the most commercially important species in order to make decisions to ensure the future of the resources,” said Maite Erauskin-Extramiana, AZTI’s researcher who led the study.

Climate effects

Results from the study suggest that high trophic level species will be more impacted by climate change than by fishing pressure under the assumption that they remain nearby their Maximum Sustainable Yield levels, or current fishing pressure.

Five species, Atlantic and Southern bluefins, swordfish, bigeye and albacore are estimated to decrease in biomass and size at different rates.

Fish price and demand are partially driven by body size and therefore, climate change and fishing can potentially reduce revenues for the fishing industry, even for the catch of stocks that are estimated to increase productivity.

“The fishing industry should adopt adaptation measures to the changing climate by increasing the value of fish through sustainability certifications and reducing fuel consumption and time at sea with higher digitalisation. Reducing fuel consumption can be also considered a mitigation measure for climate change since it comprises 5% of the total globally fishing used fuel amount and would reduce CO2 emissions,” said Erauskin-Extramiana.

But it’s not all bad news from the study. There are stocks including Pacific bluefin, yellowfin tuna and Pacific skipjack tuna where, on the contrary, increases in size are projected.

The study, which has been conducted by a team of researchers from AZTI in collaboration with the University of British Columbia, has been funded by several European and national research projects including a grant by the Government of Spain Ministry of Science and Innovation. The results have been published in the journal Global Planetary Change.

AZTI is a science and technology centre specialising in the marine environment and food that develops high-impact transformation projects with organisations aligned with the following the UN’s Sustainable Development Goals (SDGs).

 

 

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