A global expert on ocean acidification has urged Ireland to become involved in monitoring its potential impact on the State's multimillion-euro seafood sector.
Atlantic wild salmon and shellfish are among the marine species most vulnerable to falling pH levels, according to Dr Dick Feely, senior scientist with the US National Oceanic and Atmospheric Administration.
Known as the “other CO2 problem”, acidification due to increasing carbon emissions is now acknowledged as one of a trio of threats to the health of the world’s oceans, along with global warming and deoxygenation.
"Warming Up, Turning Sour, Losing Breath" is how Dr Feely subtitled his recent address on the issue at NUI Galway.
Regulate
He said the world’s oceans have helped to regulate global climate by absorbing much of the heat and increased CO2 produced by the industrial revolution.
"Up to the late 1990s this was thought to be a good thing," said Dr Feely. However, a study in the journal Science in 2004 outlining the biological impact "changed all that".
The pH of oceans has only been measured for the past 30 years, but scientists working with Dr Feely estimate CO2 levels were at 280 parts per million in the pre-industrial era, compared with 400 parts per million now.
He forecasts that if this proportion doubles there will be “enormous consequences for life on Earth, both terrestrial and oceanic”.
Global populations
This month the
World Wildlife Fund
and the Zoological Society of London reported that the global populations of some marine mammals, fish, birds and reptiles have declined by almost 50 per cent in just four decades.
Certain species are particularly sensitive to acidification, including marine pteropods, the tiny sea snails known as “sea butterflies” which provide food for salmon, herring and other fish.
“These pteropods are a key species in the food chain for wild salmon. They eat the phytoplankton that the fish don’t like, so the fish eat them in turn,” said Dr Feely
Chemical changes in the Pacific have already taken their toll on the Pacific oyster industry, he said.
“In 2007-2008 all of the spawning stock in Pacific oyster hatcheries was dying, and businesses were about to go under,” he said.
“We put sensors in tanks, and the result of it all was a $500,000 investment to raise the pH levels – saving five shellfish companies from going under.”
