New research has found that projected climate change is likely to cause the core area of skipjack tuna abundance in the Pacific to move progressively eastward, while coral reef fisheries are expected to decrease by 20 per cent by 2050.
The paper, ‘Mixed responses of tropical Pacific fisheries and aquaculture to climate change’, was published yesterday (March 11) in the journal Nature Climate Change.
The multidisciplinary work, led by the Secretariat of the Pacific Community, brought together climate scientists, oceanographers, ecologists and economists from the Pacific, Australia and France.
One of the co-authors is Johanna Johnson, an adjunct fellow at Southern Cross University’s National Marine Science Centre based in Coffs Harbour, part of the School of Environment, Science and Engineering.
Ms Johnson said fisheries and aquaculture were vital to the people of the tropical Pacific.
‘Nowhere else do so many countries depend so heavily on fish and shellfish for food security, livelihoods, economic development and government revenue,’ said Ms Johnson.
‘Maintaining these benefits in the face of rapid population growth and climate change is a major challenge.’
The researchers set out to investigate how changes to the atmosphere and the Pacific Ocean were likely to affect the food webs, habitats and stocks underpinning fisheries and aquaculture for Pacific island nations.
Coral reefs, for example, are expected to be degraded by more frequent bleaching and ocean acidification, putting some species of fish, shellfish and invertebrates under threat.
‘There are likely to be both positive and negative outcomes. Tuna catches are expected to be higher in the eastern part of the region by 2035 but lower in the west after 2050, while harvests from coastal fisheries and mariculture (cultivation of marine organisms in marine habitats, usually for commercial purposes) are projected to decrease across the region. Yields from freshwater fisheries and pond aquaculture are likely to be enhanced.’
The paper sets out how Pacific nations can address the social and economic implications, particularly for food security, as coral reefs, coastal fisheries and mariculture decline in the tropical Pacific.
‘Increasing tuna resources in the eastern Pacific and enhanced opportunities for freshwater fisheries and aquaculture production have the potential to help meet the food security needs of Pacific island communities,’ said Ms Johnson.
‘Coastal communities can adapt to the projected declines in coral reef fish production by diversifying fisheries and aquaculture resources. Transferring fishing effort from coral reef fish to tuna around inshore fish aggregating devices (FADs) will be one strategy.’