Journey to the Sea of Glass: An Underwater Expedition to BC’s Ancient Glass Sponge Reefs

On October 15th and 16th 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.


BC is the only place that reef-building glass sponges have been found.  Prior to the historic discovery, scientists only knew of glass sponge reefs from fossil records as they were thought to have gone extinct with the dinosaurs. Dr. Manfred Krautter, a leading international expert on Europe's extensive fossilized sponge reefs, called it "one of the most exciting and important scientific discoveries in the world"!

The Sea of Glass

In 1987 huge glass sponge reefs, which were once thought to be extinct, were found near Haida Gwaii. Marine biologists and conservationists were stunned and amazed. In 2001 more reefs were found in the Strait of Georgia, within sight of Vancouver. 

Glass sponges are unlike anything else in the world. They are fragile animals made entirely of glass (silica).  When they grow into reefs they become vibrant underwater cities for the many creatures that live amongst the glass sponges.

There are several individual glass sponge reefs in the Strait of Georgia, found off the Gulf Islands to the Sunshine Coast and in Howe Sound. Some of the reefs reach 14 metres in height and cover a square kilometer. They are of great importance to the oceans and to people, as they provide critical habitat for fish and filter immense amounts of seawater in an area of high industrial and human use.

Despite their importance, we are at risk of losing the glass sponge reefs as quickly as we discovered them.  The fragile reefs in the Strait of Georgia are not protected.  CPAWS-BC is championing for a marine protected area to protect the reefs before it is too late.

When the attention of conservationists turned to Canada’s newly found Sea of Glass the question was asked, ‘Will the world’s only living glass sponge reefs be protected?’

CPAWS-BC knew that the answer had to be yes. The reefs are incredibly delicate and are easily destroyed by human activities.  We have been champions of protecting these fragile animals since the 1990s. In 2010 we celebrated a huge victory when the government agreed to establish a Marine Protected Area for the reefs in Hecate Strait. Now our attention has turned to the reefs in the Strait of Georgia, and it is time to dive down and take a first-hand look at the reefs that desperately need protection. 

Photos by Sabine Jessen & Bruce Kirkby

The Expedition

Six submarine trips took place on October 15th and 16th. Juno award winning musician Dan Mangan and explorer Bruce Kirkby joined scientists, journalists and conservation on a journey to the depths of Howe Sound aboard the Aquarius submarine. A second submarine followed to film the reefs and their journey. 

The expedition provided a detailed look at the Strait of Georgia reefs. The video footage of the reefs collected on the expedition will give scientists and conservationists a clearer picture of the health and condition of the reefs, the major threats to their survival, and the urgency for protection.  

The Submarines 

Nuytco Research Ltd. is a world leader in the development and operation of undersea technology. Nuytco and its sister company, Can-Dive Construction Ltd., have over forty years of experience working around the world, including an ongoing project with NASA. Along with many scientific explorations, the Nuytco submersibles have been used for filming underwater footage for Titanic and scientific work for NASA

CPAWS would like to thank the following organisations for their support:

Submarines and Technical support                        



Backgrounder on the Glass Sponge Reefs

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