Canada - Hecate Strait and Queen Charlotte Sound Glass Sponge Reefs Marine Protected Area

In 1987, four major glass sponge reefs were discovered by the Geological Survey of Canada. These Hexactinellid (glass) sponge reefs are located between Haida Gwaii and the mainland of British Columbia in the Hecate Strait and Queen Charlotte Sound. There are four distinct sponge reefs comprising this serial site: the Northern Reef, two Central Reefs, and the Southern Reef. These sponge reef complexes are considered to be the largest living example of glass sponge reefs that were abundant in the Jurassic Period. The reefs are made up of large colonies of glass sponges and are estimated to be 9,000 years old.

The existence and formation of the reefs requires a combination of unique geological conditions combined with the occurrence of the reef-forming species of Hexactinellid sponges. The four reef complexes in the Hecate Strait and Queen Charlotte Sound discontinuously cover an area of about 1,000 km2, and are located in glacial troughs between 140 m and 240 m deep. The reef complexes are several kilometers wide, and up to 25 m tall. The sponge reefs provide refuge, habitat, and nursery grounds for aquatic species, including commercially important rockfish, other finfish and shellfish species. The species supported by the reefs are also of significant cultural importance to North and Central Coast First Nations.