The most sophisticated study yet of the sea floor of the rich fishing area beyond the Grand Banks, part of an international effort to determine if new bottom-trawling restrictions are needed, has found species of deep-water corals never believed to have been seen before in this area off Newfoundland's coast.
Research scientist Kent Gilkinson, who works for the Department of Fisheries and Oceans at the Northwest Atlantic Fisheries Centre, said that among the finds were coral species known as gorgonian, sea pen and cup coral.
“They really fit the definition of vulnerable marine ecosystems,” the benthic ecologist said yesterday, noting that coral colonies can live for centuries but grow slowly.
“Any anthropogenic impacts on these can be significant, and we don't know how quickly they will recover.”
But Dr. Gilkinson stressed it is “not necessarily overly surprising” to find these corals, and it is far too early to consider whether their presence might warrant restricted fishing methods in the area.
“We really need to look at the information and the data a bit more closely before speaking,” he said.
After three months at sea in the vicinity of the Flemish Cap and Pass, with Canadian researchers rotating through, the expedition docked in St. John's on the weekend and scientists finally got a chance to see their families.
The amount of data to be analyzed is vast. The researchers scanned nearly 38,000 square kilometres of sea floor over three months, said hydrographer Dave Sinnott, taking 200 million sonar soundings. They also collected hundreds of deep-water samples.
Part of an international effort to determine if new bottom-trawling restrictions are needed, the most sophisticated study yet of the sea floor of the rich fishing area beyond the Grand Banks has just wrapped up.
The mission stemmed from a 2006 United Nations resolution on sustainable fishing, said Loyola Sullivan, Canada's ambassador for fisheries conservation. The effects of bottom trawling were under criticism, he explained, and a closer look at the sea floor was needed to see whether some areas might be vulnerable.
“It's important that we have sustainable fisheries, and this is certainly driven by sustainable fisheries,” he said.
Spain provided the main research vessel, and the scientists also included representatives from the United Kingdom, the United States and Russia. They were at sea from spring to mid-August looking at the bottom between the depths of 700 and 2,000 metres. Next summer, they will continue into shallower waters, examining the bottom between 200 metres and 700 metres down.
The initial research was done using a multibeam sonar, a task Mr. Sinnott, with the Canadian Hydrographic Service, said is much like mowing the lawn or painting a wall. The sonar can scan a swath four metres wide for every metre of depth and the ship simply passes back and forth until the area is covered.
Raw data were fed into Mr. Sinnott's laptop computer, where the images were cleaned up and compiled into 3D pictures of the bottom. The quality of the images was greatly improved over previous data from this area, he said, and showed unusual patterns of underwater erosion and an escarpment where the depth abruptly changes from 1,200 metres to 700 metres.
“You'd need ropes to climb that, if you were on land,” he noted.
Quick processing of the images allowed the onboard ecologists to identify immediately underwater features that might be good places to look for species.
A rock dredge or a box-like scooping tool, depending on the composition of the bottom, brought up the samples.
“The cup coral just happened not to go into the bin and it rolled off on the deck,” Dr. Gilkinson recalled. “All of a sudden I heard two people shriek and say, ‘Look!' There's all sorts of excitement when these things came up.”
