Corals and Sponges of the Maritimes

Cold-water (deep-sea) corals have attracted significant scientific and conservation interest in recent years. About 25 to 30 coral species live in waters off Atlantic Canada, most of them in depths of 150 metres and greater. Several of these species are long-lived, grow to a large size (> 1 m) and can form dense concentrations, while at least one can form reefs. The large, habitat-forming species are generally found along the edge of the continental shelf and in deep channels between fishing banks.

Scientists and the fishing industry have known about the occurrence of cold water corals in Atlantic Canada for many decades. More recently, government and university scientists have conducted visual surveys in several areas of the Scotian Shelf, often utilizing the knowledge from fishing communities to identify priority areas for research. Areas of particular importance for corals have been confirmed and include areas such as the Northeast Channel, the Gully and the Stone Fence. Scientific studies are ongoing and there are likely other areas of importance in Atlantic Canada.

On Canada’s Atlantic coast, about 34 species of sponge have been identified. They can be found in shallower depths throughout the inter-tidal zone or as deep as 8 kilometres. Species such as Vazella pourtalesi form complex, three-dimensional biogenic structures on the sea floor that are believed directly and indirectly to influence the occurrence and abundance of other invertebrates and fish. Generally speaking, sponge-dominated communities modify bottom currents and create habitat. Fish use them for feeding, reproduction and resting. Sponges also filter vast amounts of water on a daily basis and serve broader roles in energy flow linking pelagic and benthic systems. Much of the information on the distribution of sponges in Atlantic Canada has been collected by fishery observers on-board commercial fishing vessels. More recently, trawl surveys have helped to identify sponge communities on the Scotian Shelf, and in deeper waters along the Grand Banks, Flemish Cap, and Labrador Shelf. Some of the organisms commonly associated with sponge grounds include several species of marine worms, rockfish, crab, shrimp and prawns.

Fisheries and Oceans Canada (DFO) has implemented conservation measures to protect coral and sponge habitats. In 2002 and 2004 DFO established fisheries closures in two areas to protect high concentrations and rare occurrences of corals: the Northeast Channel Coral Conservation Area and the Lophelia Coral Conservation Area. The Gully Marine Protected Area, established in 2004, protects a submarine canyon with a high diversity of corals.

Conservation and protection of corals and sponges and their habitats is a key component of meeting integrated management objectives. In 2006, a Coral Conservation Plan for Maritimes Region was prepared to provide a long-term strategy for protecting and understanding these important benthic habitats. An Eastern Canadian Coral and Sponge Conservation Strategy is currently in development and will help guide conservation measures for these species throughout Eastern Canadian waters.

Scientists wishing to conduct research in the Coral and/or Sponge Conservation Areas are encouraged to contact the Oceans and Coastal Management Division to request an application.

For more information on DFO’s activities related to cold-water corals or sponges, please contact the Oceans and Coastal Management Division at Fisheries and Oceans Canada, tel: (902) 426-9919, e-mail corals@mar.dfo-mpo.gc.ca

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