Glass sponge reefs

British Columbia’s prehistoric glass sponge reefs are an international treasure. Found in Hecate Strait and the Southern Strait of Georgia, these fragile reefs provide vital habitat to a wide range of marine animals including endangered rockfish, but are very sensitive to disturbances.

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Please ask the Minister of Fisheries, Oceans and Canadian Coastguard, to fully protect BC’s ancient and unique glass sponge reefs.
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They’re considered one of the great wonders in Canada’s oceans. Although world oceans have plenty of individual glass sponges, B.C.’s Hecate Strait has the only sizeable reefs. Thought to have gone extinct for millions of years, the modern-day discovery of these reefs in the late 1980s stunned the scientific community. In fact, they’ve been dubbed “Jurassic Park submerged”.  Scientists calculate these large reefs date back 9000 years – they’re an incredible living history. But they’re not simply museum relics. These reefs continue to provide huge, safe habitats for all manner of rockfish and other creatures along the North Coast.

Nine small glass sponge reefs, discovered close to communities on the Sunshine Coast, West Vancouver and Galiano Island, were recently granted some protection through fishing closures above and around the reefs to protect these fragile ecosystems from fishing gear, as of June 2015. However, B.C.'s largest reef located in Hecate Strait, near Haida Gwaii, remains unprotected, though they are headed for permanent protection through CPAW's work. In June 2010, Canada declared these dinosaur-era reefs an “Area of Interest” for an Oceans Act marine protected area (MPA) – the final stage before their protection can be legally established.

The sponges attach themselves to each other and nearby rocks, creating reefs eight stories high in some places. Although glass sponges look like plants, they are actually animals. In fact, sponges are the world’s oldest multi-cell organisms. They don’t have lungs or mouths. Instead, sponges pump water through their bodies to breathe, feed and remove waste.

There are more than 7,000 described species of sponges alive today in both fresh and marine waters and many more that remain to be described and named by scientists. Glass sponges make their skeletons out of silica (glass).



On October 15th and 16th of 2013 CPAWS BC hosted a once in a lifetime underwater expedition to explore the ancient glass sponge reefs off the coast of Vancouver on board the Aquarius submarine.
Hosted in association with Nuytco Research Ltd, the submarine expedition took high profile Canadians, scientists, journalists, and a lucky member of the public to see the extraordinary marine life that resides in the depths of our coastal waters. The submarine expedition was just one part of the story of protecting BC’s glass sponge reefs.

Click here to learn more about this incredible expedition.

The threat

Their unique skeletal structure makes the glass sponge reefs extremely sensitive to sedimentation and to physical disturbances from bottom trawling activity. In fact, over half of the large reefs in Hecate Strait were destroyed by trawlers before fishing closures were put in place by the federal government in 2002. While these reefs are now headed for permanent protection in the form of an MPA, the government has not sufficiently addressed the impacts of sedimentation to the reefs. The smaller glass sponge reefs, found in the Georgia Basin closer to human populations, are vulnerable with no current level of protection.

What CPAWS is doing

  • Hecate Strait and the glass sponge reefs are part of CPAWS’ national campaign for Canada to create new Marine Protected Area, covering at least 10% of our oceans by 2020.

  • CPAWS continues to work with the government and stakeholders on the management planning of the future MPA to ensure that the glass sponge reefs are protected from the direct impacts of trawling and indirect impacts from sedimentation.

  • B.C.’s massive reefs are also eminently suitable for World Heritage Status. They’re that precious on a global scale. When Canada takes the next step in the process and formally creates a Marine Protected Area for the reefs, CPAWS will nominate them for World Heritage status.


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