|May 06, 2013|
Arctic Ocean "particularly vulnerable" to acidification
|Climate change is affecting the Arctic Ocean in ways that may deal a severe blow to marine life and people.|
The world's oceans are becoming more acid, says a new report from the Arctic Monitoring and Assessment Programme.
And this ocean acidification in the Arctic might affect commercial fisheries in the Arctic and the marine resources that are important for indigenous peoples in the Arctic, the report says.
The Arctic Ocean is "particularly vulnerable" to acidification, says the Arctic Ocean Acidification Assessment and recommendations, which will be tabled at the Arctic Council ministerial meeting May 15 in Kiruna, Sweden.
As a result, marine ecosystems in the Arctic are "very likely to experience significant changes due to ocean acidification," states the AMAP report, being discussed at a conference in Bergen, Norway April 6 to April 8.
Over the past 200 years, the average acidity of the surface of the world's oceans has increased by about 30 per cent, scientists involved in the report said.
Ocean acidification occurs because some of carbon dioxide spewed into the atmosphere from the burning of fossil fuels dissolves in the ocean. There, carbon dioxide reacts with water to produce an acid, called carbonic acid, which causes the oceans to become more acidic.
That acidification happens faster in the Arctic Ocean because cold water absorbs more carbon dioxide than warm water. As well, the increasing supply of fresh water supplied to the sea in the Arctic from rivers and melting ice, reduces the capacity of the ocean in the region to neutralize acidification, scientists have found.
Scientists have already determined that the surface waters of Arctic Ocean are corrosively acidic during the ice-free season
The problem? This acid eats away at the shells of clam and other tiny marine life.
Increased acidity is already affecting the size and weight of shells and skeletons of urchins, sea snails and other sea creatures.
Ten years of study in the Beaufort Sea also show the seawater is becoming more acidic and fresher. Research carried out in the Svalbard Islands off Norway's northern coast also suggests Arctic seawater is likely to reach corrosive levels within 10 years.
As seawater becomes more corrosive, the impact will ripple through the food chain, making it hard for fish to find food or for whales to navigate by sound.
The AMAP report says that since the marine food chain in the Arctic is relatively simple, these marine ecosystems are vulnerable to changes when external factors affect key species.
So everything, from plankton to fish, is at risk of being affected by ocean acidification directly or indirectly, its authors say.
At the same time, Arctic marine organisms are also experiencing "other large, simultaneous changes," including climate change, harvesting, habitat degradation and pollution.
"When marine ecosystems are affected, this will also have implications for humans," scientists say.
"Ocean acidification in the Arctic might affect the commercial fishery is important to the economies of the North --- and it can affect marine resources that are important for indigenous peoples in the Arctic. The quantity, quality, and predictability of commercially important Arctic fish stocks may be affected by ocean acidification, but the magnitude and direction of change are uncertain."
That's because some fish stocks may be prove to be more robust to ocean acidification if other stresses --- for example, overfishing or habitat degradation --- are minimized.