A group of scientists, explorers, and concerned citizens are making a series of submarine dives in Howe Sound to get an up-close view of reefs of a rare glass sponge that was thought to be long extinct.

Sabine Jessen is oceans director with the Canadian Parks and Wilderness Society (CPAWS), which is hosting the expedition in partnership with Nuytco Research.

She said this particular species of glass sponge was thought to have died off 40 million years ago, but was discovered in B.C. in 1987.

"The German paleontologist Dr. Manfred Krautter, who we work with — he says discovering the glass sponge reefs in British Columbia waters was like discovering a herd of dinosaurs on land."

Jessen said B.C.'s glass sponge reefs, which are found in Hecate Strait and the Georgia Strait, are sometimes referred to as “Jurassic Park submerged.”

To raise the profile of the rarely-seen sponge, Jessen organized an expedition to take Vancouver-based, Juno-winning musician Dan Mangan and global explorer Bruce Kirkby on a series of dives in Howe Sound Tuesday and Wednesday.

They were also joined by B.C.'s Minister of Technology, Innovation and Citizens' Services Andrew Wilkinson and a group of scientists and conservationists.

The sponge reefs are located 76 metres below the surface — too deep to visit without a submarine.

Jessen explained that the sponge is an animal, not a plant, and it is actually made of partly of glass — the animals' tiny skeletons are made out of the silica it absorbs from the ocean waters.

Jessen said the sponges not only filter the water, but are nurseries for some local endangered fish species.

"There were so many tiny little rockfish, and you know these rockfish — they live for over 100 years and they are in big trouble on this coast — and and we also saw a lot of juvenile lingcod as well."

CPAWS is working to get fishing closures in place where the reefs are to protect the animals from prawn traps and fishing nets, and to eventually have the areas declared marine sanctuaries.

With files from the CBC's Terry Donnelly