Many Pacific Island nations will lose 50 to 80 percent of marine species in their waters by the end of the 21st century if climate change continues unchecked, finds a new Nippon Foundation-Nereus Program study published in Marine Policy. This area of the ocean is projected to be the most severely impacted by aspects of climate change.
"Under climate change, the Pacific Islands region is projected to become warmer, less oxygenated, more acidic, and have lower production of plankton that form the base of oceanic food webs," says lead author Rebecca Asch, Nereus Program alumnus and Assistant Professor at East Carolina University. "We found that local extinction of marine species exceeded 50 percent of current biodiversity levels across many regions and at times reached levels over 80 percent."
The Pacific Islands region is the warmest of the global ocean and experiences little seasonal variability. Because there are no drastic seasons, the marine organisms living in the tropical Pacific may find changing environmental conditions to be more of a shock.
Pacific Island nations are highly dependent on fisheries as a food source and for employment. (Image: Quentin Hanich)
"Additional warming will push ocean temperature beyond conditions that organisms have not experienced since geological time periods in this region," says co-author Gabriel Reygondeau, Nereus Fellow at UBC. "Since no organisms living in the ocean today would have time to adapt to these warmer conditions, many will either go extinct or migrate away from the western Pacific, leaving this area with much lower biodiversity."
The authors examined the effects of climate change on more than a thousand species, including those that live on coral reefs and those in open-water habitats. While both groups underwent significant declines in local biodiversity, rates of decline were noticeably higher for open-water species.
These ecological shifts would be severely detrimental to Pacific Islanders, who depend heavily on marine species for food security, economic opportunities, and cultural heritage. These challenges are further compound by rising sea levels and intensifying storms, facing developing nations with limited resources for societal adaptation.
"One hopeful point is that the extent of these changes in biodiversity and fisheries was dramatically reduced under a climate change scenario where greenhouse gas emissions were close to what would be needed for achieving the Paris Climate Agreement," says co-author William Cheung, Nereus Director of Science. "As a result, these changes in oceanic conditions are not inevitable, but instead depend on the immediate actions of all countries to materialize their commitment to limit greenhouse gas emissions."
The study "Future Marine Ecosystem Drivers, Biodiversity, and Fisheries Maximum Catch Potential in Pacific Island Countries and Territories under Climate Change" was published in Marine Policy. Read the full study here.
About the Nippon Foundation-Nereus Program
The Nereus Program, a collaboration between the Nippon Foundation and the University of British Columbia Institute for the Oceans and Fisheries, has engaged in innovative, interdisciplinary ocean research since its inception in 2011. The program is currently a global partnership of leading marine science institutes aiming to advance comprehensive understanding of global ocean systems across the natural and social sciences. Visit nereusprogram.org for more information.
For further information or interview requests, please contact:
Lindsay Lafreniere
Communications Officer, Nereus Program
Institute for the Oceans and Fisheries
The University of British Columbia
l.lafreniere@oceans.ubc.ca