"Topside, topside, be advised we have sponge at this location," senior pilot Jeff Heaton says into his communication system from a depth of 135 feet (41.1 meters).

"This is a sponge reef," says Heaton from inside the inch-thick (2.5-centimeter-thick) steel hull of the Aquarius submersible, a three-person vehicle owned and operated by Nuytco Research. "No doubt about it."

This week, the Canadian Parks and Wilderness Society (CPAWS) and Nuytco Research mounted the first submarine expedition to the glass sponge reefs found in Georgia Strait off of Vancouver.

The expedition aims to check on the status of these sponge reefs, which currently have no protection from damage by fishing activities, and to raise awareness of their existence.

The Howe Sound reef—which Aquarius will