Government Report Confirms ‘Unprecedented’ Ocean Acidification From Greenhouse Gases Threatens Canadian Atlantic Waters

Kumiko Azetse Scott writes about ocean acidification in Canada

A 2012 government report from scientists at the Department of Fisheries and Oceans warns that Canada’s Atlantic waters are “particularly vulnerable” to ocean acidification from rising greenhouse gas emissions.

Mike De Souza writes for Postmedia News, that “the government report, posted on a website without a formal announcement or news release, noted that the world’s oceans have absorbed a significant amount of carbon dioxide emissions from the atmosphere since the industrial revolution, with profound effects on marine ecosystems that could damage the Canadian economy.”

The October report, co-authored by Kristian Curran and Kumiko Azetsu-Scott from the department, focuses on what global ocean acidification “may mean for the marine ecology of the Scotian Shelf region of Atlantic Canada.” The Scotian Shelf is in the North Atlantic, which is “a global 'hotspot' for the absorption of carbon dioxide into the surface ocean.”

Unsurprisingly, Curran and Azetsu-Scott’s forecast isn’t too bright. The study notes that the present “concern regarding ocean acidification resides in its unprecedented rate of occurrence, due to the significant amount of carbon dioxide that has been added to the atmosphere over the past 250 years.”

De Souza notes that, according to the report, “marine ecosystems might be able to adapt to changes in their acidity over time periods greater than 10,000 years, but would have difficulty with emerging changes that are equivalent to a 30 per cent increase in acidity since the industrial revolution.”

The report says that further global increase in ocean acidity is “certain to occur over the coming century and longer due to present day atmospheric carbon dioxide levels, even with legislative or policy-driven reductions in carbon dioxide emissions to the atmosphere.”

Because ocean acidification and “its associated impacts cannot be easily reversed, adaptive measures coupled with a reduction in carbon dioxide emissions to the atmosphere will have to be pursued to protect ecosystems and human livelihoods against this phenomenon.”  

Curran and Azetsu-Scott mention that more studies on the effects of ocean acidification on marine life are urgently needed, saying it is uncertain at this point what lasting alterations will be seen in the ecosystem. They emphasize, though, that “any potential impacts could be severe,” and that acidification is likely to be “enough of a driver to alter species composition and dominance in a manner that could profoundly alter marine ecosystem and functioning.”

As De Souza observes, the report also addresses possible socio-economic impacts of changes to the ecosystem of the Scotian Shelf. Shellfish industries in Atlantic Canada “worth hundreds of millions of dollars and responsible for thousands of jobs” could be adversely affected, since the animals they harvest could be “negatively affected” by rising acidity levels.

In a summary, the report states that the “current situation” concerning “use of fossil fuels” and “legislated targets for carbon dioxide emission reductions” in Canada is “poor” when assessed “in terms of implications for the state of the environment.”

“To adapt to the changing environment we have to identify where the most vulnerable area is and try to reduce that added stress like pollution (and/or) overfishing,” Azetsu-Scott told Postmedia News in her first major interview about the report since October 2012.

“But still a lot of work needs to be done for adaptation,” she added, calling ocean acidification and climate change an “urgent and serious problem” for Canada.

De Souza writes that Luke Gaulton, a spokesman for Fisheries and Oceans, confirmed the Canadian government “didn’t issue a news release when it published the report.”

It was instead posted on “the website of a network with representation from government, industry, academia and non-governmental organizations.”

Image Credit: Ocean Acidification: State of the Scotian Shelf Report