Sponge reefs should be better protected, says scientist

  • Nov. 17, 2006 8:00 p.m.

The glass sponge reefs recently discovered in Hecate Strait and Queen Charlotte Sound are unique and deserve far better protection than they now have. That was the message at a meeting put on by the Canadian Parks and Wilderness Society (CPAWS) in Queen Charlotte Thursday evening (Nov. 16).
Dr. Manfred Krautter, one of the world’s leading experts in sponge reef research, told the audience of about 25 that the reefs are about 9,000 years old and were first discovered in 1988.
“I was totally electrified (when I read about them in a scientific paper). They described a living dinosaur. I fell nearly from my chair behind my table,” Dr. Krautter, of the University of Stuttgart in Germany said.
One of the reefs is about 50 km due east of Sandspit, another east of the southern end of the islands, and the third about 90 km north of Vancouver Island.
Cold water sponge reefs such as these are found only in BC. Before they were discovered, scientists thought the sponges that form them were extinct. They are the unique result of several factors, each of which is necessary for their formation and survival. First off, the composition of the coast mountain range generates a lot of silica which they need, the deep fjords on the coast ensure that only fine granules of sediment reach Hecate Strait, and there are troughs in the strait itself that funnel nutrient-laden water from the deep ocean over the reefs at a steady rate which allow the sponges to grow. As well, water temperature is always around 4 to 6 degrees, and never comes near the 15 degrees C the sponges cannot tolerate.
“Change any of the factors and you will have no more sponge reefs,” Dr. Krautter said.
The reefs, which are between 150 and 250 metres deep, cover about 1,000 square kilometres and are as high as an eight story building. They are important as habitat for other marine organisms, including juvenile rockfish and crustaceans as well as sea cucumbers and sea urchins.
They were recently nominated for UNESCO world heritage status, but ironically didn’t make the cut, In part because they are not protected by Canada.
While there’s now an agreement with the Department of Fisheries and Oceans to prevent bottom trawlers from fishing the reefs, as the trawlers scrub clean the sea floor, wiping out sponge reefs and other organisms, it’s not enough, according to Dr. Krautter. He says right now long liners are still fishing over the fragile reefs, and that can cause damage.
“That’s why we want to see these reefs as marine protected areas,” Dr. Krautter said.
“If we don’t protect them now, we won’t get a second chance. We want to make sure (they are closed) to damaging fishing gear,” he said.
One member of the audience asked if Dr. Krautter had talked to DFO, and asked “what did they say about their inactivity?”.
Dr. Krautter replied he has had discussions with fisheries, and “we spread the informationÂ…to anyone who wants to listen to it.”
Sabine Jessen of CPAWS, which sponsored the evening, told the audience there are several things they can do, including writing to the Minister of Fisheries, our MP and MLA, and trying to choose only seafood that is caught sustainably.
“Support marine protected areas and help educate your friends,” Ms Jessen said.
The evening also included a presentation on corals by Megan Baker, an intern at CPAWS.