Monday, August 28, 2017

Ocean temperatures around Nova Scotia hit record highs

Ocean temperatures around Nova Scotia hit record highs: DFO report
Temperatures on Scotian Shelf were up by 2 or 3 C in some places
By Paul Withers, CBC News Posted: Aug 25, 2017
Canadian Broadcasting Corporation

Ocean temperatures in the Scotian Shelf and the Gulf of St. Lawrence reached record or near-record highs in 2016, according to a Fisheries and Oceans Canada report on Atlantic Canada's marine ecosystem.

Federal fisheries scientist Dave Hebert said temperatures on Nova Scotia's Scotian Shelf were up by 2 or 3 C [3.6 to 5.4 F] in some places.

"Most were well above normal. Some were record highs," said Hebert, who works out of the Bedford Institute of Oceanography in Dartmouth, N.S.

One of those records was set last October, 32 kilometres off Halifax where the ocean bottom exceeded 11 C.

He said the average ocean temperature for the Scotian Shelf in 2016 was the second highest on record in 47 years, with 2012 being the highest.

The Gulf of St. Lawrence set a 102-year record for temperature in deep water with a depth of 200 to 300 metres.

"This is more concerning than the variations of temperature on the surface of the water," said Peter Galbraith, a researcher at the Maurice Lamontagne federal fisheries institute in Mont-Joli, Que.

He said this is because these deep water temperatures have not been seen before, it's not known what the impact will be.


The warming water coincides with a shift in where zooplankton are residing. Known as copepods, this food source is eaten by the endangered North Atlantic right whale.

More of the whales are moving from their traditional Canadian feeding grounds in the Roseway Basin off southern Nova Scotia and the Bay of Fundy in search of food.

"Those zooplankton are now in the Gulf of St. Lawrence. That's probably the reason the whales are going to where they are going because the temperatures aren't quite as warm as they are in the Scotian Shelf," said Hebert.

The question is whether the zooplankton are leading the whales into a shipping lane super highway.

Since June, at least 10 right whales have been found dead in the gulf. Several deaths have been attributed to ship collisions or fishing gear entanglements.

The federal government responded by imposing a speed limit and temporarily closing some fishing grounds.


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