December 7th, 2016 by James Ayre
The ocean acidification that’s now occurring, as a result of increasing anthropogenic levels of carbon dioxide emissions, will led to cascading losses of biodiversity in many marine habitats and ecosystems, according to new research from the University of British Columbia and its partners.
The new work is some of the first to investigate the likely effects of ocean acidification on whole ecosystems, rather than just on individual species (corals, kelps, seagrasses, phytoplankton, etc).
“Not too surprisingly, species diversity in calcium carbonate-based habitats like coral reefs and mussel beds were projected to decline with increased ocean acidification,” stated UBC zoologist and biodiversity researcher Jennifer Sunday.
Ocean acidification (which is actually a move towards neutral pH, from slightly basic pH) will of course result in the disappearance of a great many of the lifeforms living in the world’s oceans that rely on waters saturated with calcium carbonate for the maintenance and construction of their: bodies, shells, colonies/skeletons, etc. these animals include: corals, mussels, oysters, crabs, lobsters, and various plankton, etc.
Sunday continued: “The more complex responses are those of seagrass beds that are vital to many fisheries species. These showed the potential to increase the number of species they can support, but the real-world evidence so far shows that they’re not reaching this potential. This highlights a need to focus not only on individual species, but on how the supportive habitat that sets nature’s stage responds and interacts to climate change.”
The press release provides details on the new work: “The researchers combined data and observations from 10 field studies that measured the impact of underwater volcanic vents, which release carbon dioxide and mimic the conditions of future ocean acidification, on the density of habitat-forming species. They combined that data with 15 studies looking at how changes in habitat typically impact local species to make their predictions.”
“We’ve known for a while that there will be big losers and some winners with climate change,” stated UBC marine ecologist Christopher Harley, senior author on the paper. “We don’t have time to measure the impact of climate change on each individual species, but using this approach allows us to make reasonable predictions. Now we have a much clearer picture of how some losers can drag biodiversity down with them, and how some other species might be able to help their habitat mediate a response to acidification. For example, in the Pacific Northwest, the number of medium to large-sized edible saltwater mussels is likely to decrease as the chemistry of our oceans changes, and this is bad news for the hundreds of species that use them for habitat.”
The press release continued: “The researchers focused their study on the impact of ocean acidification on coral reefs, mussel beds, kelp forests, and seagrass meadows that form the homes of thousands of marine species. They used observations of altered habitats around the world to project how changes in these habitats brought on by ocean acidification will impact the number of species that each habitat can support.”
These predictions were then tested against real-world data obtained at a coral reef close to Papua New Guinea, and a collection of Mediterranean seagrass beds. In both locations the research findings appear to have been validated — with increasing ocean acidification leading directly to cascading losses of biodiversity in the coral reef.
Notably, though, there were no increases in the biodiversity found in the Mediterranean seagrass ecosystems with rising acidification, as had been predicted. Not a good sign.
The findings of the new research are detailed in a paper published in the journal Nature Climate Change.
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