As researchers and diplomats ready themselves for a major United Nations conference on the state of the world’s oceans, the Canadian Climate Forum has released a report on acidification in domestic waters, surveying the state of knowledge of the phenomenon for the first time.
The combination of warming oceans and acidification is occurring faster and with greater intensity at high latitudes – precisely the sort of latitudes Canada’s three coasts are located in.
The researchers note that there have been only a few high quality analyses performed in Canadian coastal waters, notably in the Pacific, the St Lawrence estuary and the Labrador Sea. However, such studies are only beginning and do not yet offer an understanding on season-to-season change. The pH ‘climatology’ of Canadian waters is still largely unknown, the report states.
What we do know so far is that the impacts of acidification vary considerably depending on other conditions. For example, areas can be particularly vulnerable where water circulation is restricted. On the west coast in particular, subsurface corrosive Pacific water wells up on the outer continental shelves from south of Vancouver Island to north of Haida Gwaii. This then feeds into the restricted circulation of the Strait of Georgia. On the east coast, the researchers say that the Gulf of St Lawrence is especially vulnerable to CO2 added from the atmosphere because of restricted circulation due to shallow sills or narrow passages. As a result, CO2 cannot easily escape from the subsurface water to the atmosphere. In fjords along some parts of the Canadian coastline, carbon dioxide can build up in deeper waters with reduced circulation as organic matter sinks and decays, which together with GHG-driven acidification, can exacerbate the problem, producing comparatively sharp but local increases in acidification.
In the Arctic, pteropod plankton, which are a key food source for fish, whales and birds, face the greatest danger. Projections suggest that they will be unable to form their shells in the Arctic by the end of the century.
The researchers conclude that Canada needs to up its game with respect to high-quality monitoring of the issue. In addition, real-time monitoring of oyster and other shellfish impacts is needed along with measures to try to control pH and temperature in aquaculture facilities. Adaptation measures include breeding of more robust species of animals using the latest genetic technologies, and identifying those locations where wild fisheries are most at risk.
Next week, the UN headquarters in New York is to host the first ever oceans conference. The aim is to be a game-changer that will reverse the decline in the health of the world’s oceans in the way that previous UN climate diplomacy has led to global action to tackle climate change. Ocean acidification will feature prominently in the conference. PICS executive director, Sybil Seitzinger, will be a panelist on a session on ocean pollution.
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