Corals and sponges might look like plants but they are actually animals! Unlike many animals they don’t move on their own; in fact, they only move with the ocean current. When you think coral, you probably start dreaming of snorkeling off the coast of Australia and exploring the Great Barrier Reef, but there are corals in other places around the world. Off the coast of Canada are two reefs, the rocky reefs off the west coast of Canada in the Pacific Ocean and the cold, deep-water corals off the east coast of Canada in the Atlantic Ocean. Today we’re heading east into the Atlantic Ocean to learn some fascinating facts about deep-water coral.
Worldwide, over 700 species of cold, deep-water corals exist and right here in Canada we have some pretty amazing species. About 2-5 km deep in the Atlantic Ocean, off the east coast of Canada, live over 40 known species of cold, deep-water corals. These corals are adapted to growing without any sunlight and in very cold water (usually below 2°C). They can also withstand water pressure of 1,000 kg/cm2.
Deep-water corals are a bit different than tropical corals that live in warm water. Since deep-water corals live at such extreme water depths, they must be able to grow without any sunlight. Tropical corals, on the other hand, need light to grow. They have very tiny plant-like particles living INSIDE their cells that use energy from the sun to produce food for the coral. Cold, deep-water corals lack these tiny “plants” inside their cells so they do not need the sun to live and grow. It’s incredible how well adapted animals and plants are to their surroundings.
Lophelia pertusa: A deep-water stony coral
Sea pens: A soft coral formed from rows of polyps that look like an old-fashioned quill pen.
Gorgonian coral or sea fans: Some colonies can be over 100 years old and are sometimes so dense that scientists refer to them as coral “forests”. They are one of the largest coral species, found at depths of 200-1,000 meters underwater.
Bamboo corals: This type of deep-water coral has a skeleton inside made of hard calcium-based crystals. A long living coral species, some have been found to be 4,000 years old.
- Kenchington E and D Fenton (2008). Oasis of the deep: cold water corals of Atlantic Canada. Dept. of Fisheries and Oceans, Canada. Bedford Institute of Oceanography. http://www.lophelia.org/corals/basics/key-species http://www.science.gc.ca/default.asp?lang=En&n=EE39B64D-1 http://www.ucs.louisiana.edu/~scf4101/Bambooweb/Research_FS.htm http://www.dfo-mpo.gc.ca/oceans/publications/cs-ce-2009-eng.pdf