TOM HEVEZI/THE CANADIAN PRESS/AP The behaviour of northern bottlenose whale is the most visible way scientists have of determining the relative health of the Sable Gully, the largest submarine canyon in eastern North America.

Whales in Sable Gully helping scientists protect ecosystem

KEITH DOUCETTE
THE CANADIAN PRESS
SEPT 25/07

    HALIFAX - An endangered species of whale that can dive as deep as a kilometre to feed is helping scientists determine how to protect an unusual marine ecosystem off Canada's East Coast.
   Observations of northern bottlenose whales in the Sable Gully - the largest submarine canyon in eastern North America - are proving to be an effective way to determine the health of the area, federal Fisheries Department scientists told a news conference Monday.
   "If the whales are doing well, we can probably assume that the underlying ecosystem is still fairly robust and supportive'" said Paul McNab, who manages the marine protected area about 200 kilometres southeast of Halifax.
   "Whales become a fairly easy study indicator because you can go out there on the surface and take photographs, you can count whales, you can look at whether they are still reproducing."
   A group of marine scientists recently completed a two-week trip to the gully to study deep-water animal life, some of which makes up the diet of the northern bottlenose.
   The work complemented an earlier study, carried out in July, in which sci entists used a submersible to probe the depths off Nova Scotia and Newfoundland.
   The small, remotely controlled sub was used to capture pictures of rare corals and fish that inhabit the dark, craggy floor of the gully.
   Lead scientist Trevor Kenchington said the more recent trip, which wrapped up last week, involved the use of the Canadian Coast Guard vessel Wilfred Templeman, which captured marine life in a trawling net that was pulled about a kilometre under the surface.
   The 60-metre-wide net was pulled through the gully, but it never came close to the bottom, Kenchington said.
   More than 220 species of fish, squid and various shrimp-like crustaceans were lifted to the surface.
   "I've been a marine scientist for about 30 years (and) I have never known a single trip to sea to get us as much knowledge as this one aid," said Kenchington.
   Many of the species observed were recorded for the first time in Canadian waters, although the scientists were unsure whether any of them are "totally new" to science.
   Kenchington said one "weird and wonderful" creature was particularly puzzling. "It looks like somebody put a filet of smoked salmon into the net. It's about the consistency of rather thick Jell-O and none of us have a clue what it is:'
   Other creatures caught in the net included lanternfish, a tiny fish with big eyes that emits a bluish light to hide from predators as it emerges from the depths to feed near the surface at night.
   From greater depths, scientists came face to face with several ghastly predators, including the aptly named ogre fish. While adults are only about 15 centimetres long, their menacing fangs make them look like something conjured for a horror movie.
   "That's the world down there: lots of horrible looking, but quite small predators waiting for things like the lanternfish to come swimming down to be swallowed," said Kenchington.
   The catch also included plenty of"weird squids", including the armhook, a squid with hooks like cat claws. It is one of two species of squid that comprise the main diet for the bottlenose whale.
   Kenchington said by learning more about the gully's creatures and what sustains them, scientists will have a better idea of what to protect.
   "We do know the whales are there and we know the whales are important to Canadians. We know they are feeding, therefore we really want to know why their food is there:'

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