A group of rare, glass sponge reefs off B.C.'s north coast have been selected for potential designation as marine protected areas, Fisheries and Oceans Minister Gail Shea announced on Tuesday.

B.C.'s living glass sponge reefs in Hecate Strait and Queen Charlotte Sound are the only reefs of their kind in the world, and the announcement was met with applause by conservation groups.

The federal government has designated the reefs an area of interest, the first step towards permanent protection.

For thousands of years, the glass sponge reefs have flourished in Hecate Strait and Queen Charlotte Sound, but they were only discovered in 1987.

They're made of fragile glass or silica that has not broken down as the sponges die. Instead the reefs have grown to the height of eight-storey buildings in some places.

Sabine Jessen from the Canadian Parks and Wilderness Society calls the reefs one of the natural wonders of the world.

"They are found alive nowhere else in the world," she said. "They were thought to have gone extinct with the dinosaurs."

Jim Boutilier, an invertebrate scientist with the Department of Fisheries and Oceans in Nanaimo, also welcomed the protection of the amazing natural wonders.

"It's sort of like a scene from Alice in Wonderland," he said. "Every time you go down, you see little fish hiding in the holes that are associated with the currents in the sponges and those kind of things. It's beautiful."

Fishing nets are main threat

Researchers believe that the largest living glass sponge specimens may be 200 years old. Sponges live at depths of 165 to 240 metres, and the reefs can grow to be 21 metres tall.

One of the main threats to the reefs was bottom-dragging of nets by fishing trawlers, which have been banned from the area covering about 1,800 square kilometres in recent years, according to Jennifer Lash, the executive director of the Living Oceans Society.

"These reefs are unique, and today’s announcement is a great step forward for marine conservation," said Lash. "Hopefully, final MPA designation will be announced by 2012, and the glass sponge reefs will be protected in perpetuity."

A marine protected area is a designation for an area that significantly contributes to the health of marine ecosystems, and Ottawa has committed to establishing a network of such sites by 2012.

An area of rich biodiversity within the Laurentian Channel off the coast of Newfoundland and Labrador is also being considered, the minister also announced on Tuesday.