A recent study, published in the Nature Journal npj Ocean Sustainability, reveals that deep-sea mining activities could disrupt the expected changes in tuna migration patterns driven by climate change. Seafood groups, alarmed by these findings, have issued a joint letter advocating for a suspension of deep-sea mining plans.
The study, focusing on three tuna species, anticipates alterations in migration patterns due to climate change. Two emission scenarios, one with moderate and the other with high emissions, were examined. Notably, the study predicts a rise in the total biomass of bigeye (10-11%), skipjack (30-31%), and yellowfin tuna (23%) in the Clarion-Clipperton Zone (CCZ) by 2050. The CCZ, located southeast of Hawaii in the Pacific Ocean, is earmarked for potential deep-sea mining.
Dr. Juliano Palacios Abrantes, co-author of the study from the University of British Columbia, emphasizes the economic dependence on the biodiversity of the high seas. He expresses concern that deep-sea mining adds another layer of uncertainty to the impact of climate change on tuna species and associated fisheries.
Potential impacts on tuna species outlined in the study include sediment plumes hindering feeding and communication, as well as the absorption of toxic metals. Noise and light pollution from mining activities could disrupt behaviour, reproduction rates, induce stress, and alter migratory routes.
The clash between valuable fisheries and mining companies in the CCZ is anticipated. The Global Tuna Alliance, representing 32% of global tuna sales, and the Sustainable Seafood Coalition, comprising 45 British seafood firms, jointly criticize the United Nations body regulating high seas seabeds. Citing the study, these groups express deep concern over the significant overlap between future fishing grounds and areas designated for mineral exploration.
Ahead of the upcoming International Seabed Authority (ISA) meeting, the groups call for a pause, citing environmental and economic risks. Daniel Suddaby, Executive Director at Global Tuna Alliance, remarks on sailing into “uncharted territory” with unknown risks posed by deep-sea mining in critical high-seas regions for tuna species.
Professor Douglas McCauley, co-author of the study, warns against rushed decisions that could harm ocean ecosystems crucial for environmental balance, planetary health, and global food security. The groups collectively stress the need for careful consideration before proceeding with deep-sea mining initiatives.
