Press Release
March 30, 2006
Research shows rare glass sponge reefs important to rockfish
Calls for legal protection of the 9000-year-old glass sponge reefs in Hecate Strait are being renewed as research shows the reefs are important for the survival of threatened rockfish populations off BC's coast.
"The Hexactinellid, or glass, sponge reefs provide critical nursery habitat for BC's vulnerable rockfish species," says UBC graduate student Sarah Cook, author of the research. "Juvenile rockfish are 10 times more abundant in the sponge reefs than in nearby areas."
Cook's research has been supervised Dr. Manfred Krautter, one of the world's leading experts in sponge reef research, from the University of Stuttgart.
"It has been 18 years since the sponge reefs were discovered and they don't exist anywhere else on Earth, yet they still don't have long-term, permanent protection," says Krautter. "I'm shocked to see that the Canadian government hasn't awarded long-term protection to a feature of such global importance."
"We've asked the last four Ministers of Fisheries and Oceans to give the sponge reefs permanent protection," says Sabine Jessen, conservation director of Canadian Parks and Wilderness Society, BC chapter (CPAWS). "We hope that Minister Hearn will show leadership and designate the sponge reefs as marine protected areas."
A recent study by Natural Resources Canada to map the sea floor determined that the actual shape and size of the sponge reefs are different from what was known when bottom trawl closures were instituted in 2002.
"The trawl closures do not cover the entire extent of the reefs," says Jessen. "Nearly 18 per cent of the complexes are not contained in the 2002 closure and 70 per cent of reef complex ‘B' is outside the boundaries," says Jessen.
CPAWS is calling for DFO to alter the boundaries of the bottom trawl closures, expand the closures to all types of fishing, and implement a five to eight kilometre buffer zone.
"A buffer zone was recommended by DFO's science branch in 2002, but was not included in the established trawl closures," says Jessen. "We would like to see DFO listen to its own scientists and add a buffer zone to the new boundaries."
"Rockfish are long-lived, slow-maturing animals," says Cook. "These old-growth fish can live to be over 100 years old. They stay close to their home territories and don't survive being caught and released, and so are easily fished out."
"Rockfish are experiencing severe population declines due to over-fishing," says Jessen. "Current populations are only five per cent what they were in 1900. Juvenile habitat, like that provided by the sponge reefs, is therefore critical to their recovery."
Glass sponge reefs were only known as fossils until they were discovered off BC's coast in 1988. Fifty per cent of the reefs has already been destroyed.
Fisheries and Oceans Canada implemented mandatory groundfish trawl closures around the four reefs in Hecate Strait in 2002 to prevent further damage. Smaller reefs later discovered in the Strait of Georgia still have no protection at all.
"The Hecate Strait sponge reefs are unique in the world and that alone should merit international recognition and long-term protection as a marine protected area," says Jodi Stark, marine campaign coordinator for CPAWS-BC. "We now know that the reefs provide vital habitat for threatened rockfish species."
Cook's research also found that areas of glass sponge reefs destroyed by trawling recuperate extremely slowly, if at all. "These sponge reefs are growing in deep, dark, cold environments," says Cook. "As a result, they grow, reproduce and recolonize very slowly."
CPAWS - British Columbia Chapter