By Mike Urch, SeafoodSource contributing editor
Published on 31 March, 2014
A massive 24 million metric tons (MT) of carbon dioxide produced by industrial practices are absorbed by the seas every day, says Roger Harrabin for the BBC's Newsnight program. The gas dissolves into the water forming carbonic acid.
The BBC sent Harrabin, its environment analyst, to join an international research vessel on an expedition to Normanby Island on the far tip of Papua New Guinea to study the effects of carbon dioxide on the ocean. According to Harrabin, streams of volcanic carbon dioxide bubbles emerge from deep under the seabed there, "like a giant jacuzzi." Their acidity is inarguably harming the local sea life, he said.
"Only tough old boulder corals can survive here. The beautiful branching corals can't cope. It's a huge loss because the branching corals play a vital role in the reef ecosystem, protecting the young fish needed to help feed a hungry world population."
Research at the volcanic vents shows that between 30 to 50 percent of coral types won't be able to cope with the carbon dioxide levels expected for the world's oceans this century.
The lead scientist, Katharina Fabricius from the Australian Institute of Marine Science, told Harrabin: "There will be winners and losers as ocean acidity increases. Seaweed and seagrass are thriving under higher carbon dioxide levels. But many species lose out. We are very concerned because the baby corals find it very hard to survive in high [concentrations of] carbon dioxide so reefs won't be able to repair themselves. It's very, very serious."
Fabricius is one of several laboratory researchers working to see how creatures deal with high carbon dioxide levels and the elevated temperatures predicted to accompany it.
Terry Hughes, director of the Centre for Reef Studies at James Cook University in Australia, said acidification is the latest threat to reefs. "We've already lost a third of coral reefs thanks primarily to pollution and overfishing," he told Harrabin. "Both are accelerating. Now there's the added imposition of global warming and, in future, ocean acidification. I'm very worried about acidification. Some coral species will substitute for others, but if you lose table corals and tall branching corals, most of nooks and crannies — the hiding places for juvenile fish — will disappear. And it'll directly affect human beings because fish stocks will be affected."
Research on acidification is now spreading from corals to fish. One group of scientists at the university is chasing fish in a barrel to see if their athleticism is compromised by water that could be 170 percent more acidic than pre-industrial times by the century's end (although still alkaline overall).
According to the Newsnight program, tests already show acidification makes some fish lose their sense of smell and behave recklessly in the presence of predators.
A draft U.N. report also warns that mass extinctions happened in the past, when carbon dioxide levels changed more slowly than they are changing now.
"The changes we're making are irreversible for tens of thousands of years," Fabricius said. "We can protect reefs from over-fishing and local pollution if there's a will. But with the atmosphere and oceans it's completely different — there's nothing to remove the effects of carbon dioxide from the system. It's terrible."
Whether publication of the U.N. report will have any effect on the amount of carbon dioxide released into the atmosphere and from there absorbed into the world's oceans is doubtful. Until there are obvious adverse affects on catching fish for human consumption there probably won't be any concerted effort by governments to reduce carbon dioxide emissions and by then it will probably too late.