Monday, 16 March 2015

Ocean sinks failing - acidification crisis in N. America's shellfish industry
A collapse of West Coast scallop hatcheries is reported in Desmogblog (20 June 2014excerpt): 

In 2013, 25 years of smooth sea scallop farming at Island Sea Scallops suddenly came to an end. Years of dealing with a 10 per cent mortality rate, suddenly hit 90 to 95 per cent,CEO Rob Saunders told DeSmog Canada from his office in Qualicum Beach, B.C.
Over 10 million scallops died from the 2010, 2011 and 2012 batches. It was an unprecedented die-off and Saunders attributes their deaths to an increasingly acidic ocean. Saunders’ tests reveal the pH balance of the water used in his nursery dropped from the average of 8.2 to 7.2.
Some uncertainty still remains as to the cause of the die-off, but scientists have shown the growing amount of carbon dioxide in the atmosphere is increasing the acidity of the oceans and inhibiting “the development and survival of larval shellfish.”
The Vancouver Aquarium’s records show the pH level in the Vancouver harbour has dropped from 8.1 in the 1970s to a low of 7.3 in 2001. And shellfish farmers up the Pacific Coast have been reporting massive die-offs for almost a decade.
A lot of people criticize me, saying you can’t prove it and of course I can’t, but the correlation is pretty strong,” says Saunders.
Islands Scallops along with the federal Department of Fisheries and Oceans are undertaking a research project to determine the root cause of the massive scallop die off.
This year, Island Scallops introduced a new heartier species of scallop and quickened harvest rates, “because we don’t expect the animals to live for two years,” said Saunders. The pH level is up a bit to 7.6, but Saunders is still seeing a 40 to 50 per cent mortality rate.
Am I feeling desperate – absolutely,” said Saunders “If you want to maintain a coastal industry, then we are going to need some help – we are going to need some help now, not two years from now.”
The Boston Globe's title "Rising acid levels in oceans imperil region’s shellfish: changes from surge in carbon dioxide take toll" (7 Mar 2015) is somewhat misleading; the acid levels it reports in Maine rivers come from precipitation. But the "canary in the mine" role of hatcheries as a monitor is significant. The article also notes a "shellfish crash" in the Pacific Northwest. According to an (over-optimistic?) NOAA report, that crash was reversed. It doesn't say exactly how, but presumably the hatcheries dam off acid waters, or time the hatchling release.

None of this will help the poor and vulnerable of the world who cannot afford fancy tech fixes. For instance, the Seattle Times' Seachange: food for millions at risk (21 Dec 2014).  

No comments: