After 10 Years as a Marine Protected Area,
the Sable Gully Continues to Yield its Secrets
The Sable Gully Marine Protected Area (Gully MPA), established in 2004, is located 200 kilometres off the coast of Nova Scotia, to the east of Sable Island. Over 65 kilometres long and 15 kilometres wide, the Gully is one of the most prominent undersea features on the east coast of Canada. It contains the largest underwater canyon in eastern North America, a diverse space where many different deep-water fishes, dolphins, whales, and even centuries-old coral live. The Gully was the first MPA to be established in Atlantic Canada. Since 2006, the Government of Canada has designated three new Marine Protected Areas under the Oceans Act: Musquash Estuary in New Brunswick, Bowie Seamount off the coast of British Columbia, and Tarium Niryutait in the Beaufort Sea.
Coral reefs are some of the most diverse and valuable ecosystems on Earth. The Gully MPA was established in part because it was known to be an area where cold water corals existed. Early records of coral in the Gully identified 14 different species including six species of large branching corals that fishermen call “trees”. Between 1997 and 2003, researchers from the Bedford Institute of Oceanography (BIO) used an underwater camera developed at BIO called Campod in identifying these species.
While Campod allows scientists on board a ship to view the bottom as it drifts over the sea floor, it is limited to relatively shallow depths. As such, early observations of corals were mostly collected from depths of less than 500 metres.
The deepest parts of the Gully reach depths of more than 2,500 metres and the creatures living there remain largely undiscovered. In 2006 the first extensive deep water explorations in the Gully were made using a remotely operated underwater vehicle owned by the Department of National Defense. This vehicle, reaching depths of 2,500 metres, was the first to explore the deep feeder canyons that link with the main canyon. In 2007 this exploration was followed by similar surveys of the canyon floor using the Remotely Operated Platform for Ocean Sciences (ROPOS) owned and operated by the Canadian Scientific Submersible Facility of British Columbia.
The ROPOS mission collected nearly 90 hours of video and 1,034 high resolution images over six dives covering approximately 34 kilometres of ocean bottom. This mission found 11 more species of coral in the Gully, including seven species of sea pens living in the soft sediments of the canyon floor, three more species of coral trees, and a species of black coral. Over 18,000 individual corals were counted, increasing the number of records from the Gully by more than 100 times!
Coral explorations have continued and in 2011 scientists from BIO explored the eastern wall of the Gully where they discovered vast forests of bamboo coral. The Gully MPA continues to yield its secrets with each new expedition and one of the original purposes of preserving the diversity of coral species known to occur in this amazing canyon has been fully justified.
Dr. Ellen Kenchington
Oceanography and Climate Section
Fisheries and Oceans Canada
Bedford Institute of Oceanography
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