Saturday 18 November 2017

Pacific threat: 80 percent of fish set to be wiped out as ocean temperatures surge

Pacific Island nations are expected to lose 50 to 80 percent of fish species by the end of the century.
The alarming number was published in a study by the Nippon Foundation-Nereus Program in Marine Policy. The oceans in the Pacific Islands in particular, according to the study, are expected to be the most severely affected by climate change in the next century. These waters are already the warmest of the global ocean, and with less seasonal variability, animals in this area may be more shocked by changing conditions.
“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,” Rebecca Asch, lead author of the study and assistant professor of in the biology department at East Carolina University, said in a statement. “We found that local extinction of marine species exceed 50 percent of current biodiversity levels across many regions and at times reached levels over 80 percent.” 
People who live in the Pacific are dependent upon these species for food and livelihoods, the authors wrote. Across most of the region, fish constitute more than 20 percent of the animal protein people consume—and in some countries, it’s as high as 50 percent. The fishing industry in the Pacific could also be decimated, as well as small-scale fisheries and subsistence fishing. Tuna licenses sold to other countries make up to 60 percent of tax revenue for some countries and territories. Travel and tourism—greatly influenced by unique fish species—make up 12 to 13 percent of the GDP in Oceania.
“The socio-economic vulnerability of the region to marine climate change impacts is also underscored by the fact that the capacity of Small Island Developing States (SIDS) in the tropical Pacific to adapt to or mitigate climate change impacts may be lower than that of developed countries,” the authors wrote in the study. 
“Additional warming will push ocean temperature beyond conditions that organisms have not experienced sine geological time periods in this region,” co-author Gabriel Reygondeau, Nereus Fellow at the University of British Columbia, said in a statement. “Since no organisms living in the ocean today could 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 study calculated that 80 percent of marine species would die or migrate elsewhere if Pacific Island countries and territories experience a 3 to 4 degrees Celsius increase in sea surface temperature by the end of the century. Massive drop-offs of marine species could also be curbed with immediate changes in greenhouse gas emissions, which would reduce how high sea surface temperatures could rise.  
Nearly 200 countries have been meeting in Bonn, Germany, for a global climate change conference to discuss how to implement the standards set in the 2015 Paris Agreement. The authors noted that achieving those goals would greatly reduce how many species are expected to be wiped out in the Pacific.
“As a result,” co-author William Cheung, director of science at the Nereus Program, said in a statement, “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 as is being discussed in COP23 in Bonn, Germany this week.”

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