A new study has found that the majority of marine life in Marine Protected Areas will not be able to tolerate the increase in ocean temperatures associated with climate change.
Marine Protected Areas (MPAs) have been established across the world’s oceans as a haven to protect threatened marine life. MPAs limit human activity in an area for a conservation purpose, typically to protect natural or cultural resources, however global warming is now likely to have devastating effects on marine ecoystems.
The research from the University of North Carolina at Chapel Hill and collaborators published this week in Nature Climate Change, predicts that under the Intergovernmental Panel on Climate Change’s Representative Concentration Pathway 8.5 emissions scenario, better known as the “business as usual scenario,” marine protected areas will warm by 2.8 degrees Celsius (or 5 degrees Fahrenheit) by 2100.
The study concludes that such rapid and extreme warming would devastate the species and ecosystems currently located in marine protected areas. This could lead to extinctions of some of the world’s most unique animals, loss of biodiversity, and changes in ocean food-webs. It could also have considerable negative impacts on the productivity of fisheries and on tourism revenue. Many of these marine species exist as small populations with low genetic diversity that are vulnerable to environmental change and unlikely to adapt to ocean warming.
“With warming of this magnitude, we expect to lose many, if not most, animal species from marine protected areas by the turn of the century,” said John Bruno, lead author, marine ecologist, and biology professor in the College of Arts and Sciences at UNC-Chapel Hill. “To avoid the worst outcomes, we need to immediately adopt an emission reduction scenario in which emissions peak within the next two decades and then decrease very significantly, replacing fossil fuels with cleaner energy sources like solar and wind.”
Marine Protected Areas are protected by local, state, territorial, native, regional, national, or international authorities and differ substantially among and between nations. This variation includes different limitations on development, fishing practices, fishing seasons and catch limits, moorings and bans on removing or disrupting marine life. Types of MPAs include marine sanctuaries, estuarine research reserves, ocean parks, and marine wildlife refuges, with 8,236 MPA’s in total across the globe. However, MPAs only cover about 5% of the surface of the ocean.
The team’s findings revealed that mean sea-surface temperatures within Marine Protected Areas are projected to increase 0.034 degrees Celsius (or 0.061 degrees Fahrenheit) per year, with MPAs in the Arctic and Antarctic projected to warm especially quickly, threatening numerous native marine mammals like polar bears and penguins. They concluded that MPAs at the greatest risk include those in the Arctic and Antarctic, in the northwest Atlantic, and the newly designated no-take reserves off the northern Galápagos islands Darwin and Wolf.
“There has been a lot of talk about establishing marine reserves to buy time while we figure out how to confront climate change,” said Rich Aronson, ocean scientist at Florida Institute of Technology and a researcher on the study. “We’re out of time, and the fact is we already know what to do: We have to control greenhouse gas emissions.”
John F. Bruno, Amanda E. Bates, Chris Cacciapaglia, Elizabeth P. Pike, Steven C. Amstrup, Ruben van Hooidonk, Stephanie A. Henson, Richard B. Aronson. Climate change threatens the world’s marine protected areas. Nature Climate Change, 2018; DOI: 10.1038/s41558-018-0149-2
The Great Barrier Reef, one of the world’s largest Marine Protected Areas.