Just discovered in 1987, these unique, very ancient and very fragile Glass Sponge Reefs were found 200 meters deep off the Pacific coast of British Columbia.

Neil_McDaniel glass sponge reef mpa british columbia canada

Until this discovery, only fossils, found across most of Central Europe, told the story of glass sponge reefs. 220 million years ago, the ancient Tethys Sea stretched across the continent and within it thrived the glass sponge reefs. They existed for 180 million years, forming before the first dinosaurs and outliving the last dinosaur. (photo – Neil McDaniel)


“largest animal made structure ever built on earth.”

glass sponge reef fossil-cliff sabine jessenToday enormous cliffs from Portugal to Romania reveal the fossilized remains of what had been “the largest animal made structure ever built on earth.” From these cliffs the fossil record indicated that the reefs had gone extinct about 40 million years ago. (photo – Sabine Jessen)

While mapping the seafloor of the Hecate Strait, between Haida Gwai and North Vancouver Island in 1987, a Canadian team came across huge and mysterious mounds on the ocean floor.

Not until they took a closer look via a remotely operated, underwater camera did they realize that they were viewing a garden of living fossils. A 9,000 years old garden that stretched for hundreds of kilometers.


“One of the Most Exciting and Important Scientific Discoveries”

The Canadian scientists aboard the oceanographic science vessel CCGS John P. Tully were unaware that they were the first humans to ever set eyes on a “living” glass sponge reef. The researchers believe that the reef started to form shortly after the last ice age.

glass-sponge-reef euplectella venus flower basket noaa

Individual glass sponges are known to exist in all the world’s oceans but not as entire reefs. On the Canadian reefs they have grown, for thousands of years, one atop the other to heights of an eight-story building. (photo – NOAA)

Further explorations have uncovered additional reefs along the coast of British Columbia and north to Alaska. But, the reefs found in the Hecate Strait remain the largest. It is thought that the right temperatures and currents with unusually high levels of silica and oxygen provide the perfect conditions for these reefs to flourish.


Glass Sponge Reefs, Ancient and Extremely Fragile

There appear to be three species of glass sponges. All are extremely fragile, some like the cloudlike Farrea occa has translucent tissues only one millimeter thick.

Some of these reefs are alive, others not, one was smothered by the waste from a net-pen fish farm near Vancouver Island.

glass sponge reef fishing trawling nets damage“Glass sponges are as fragile as they sound. They have the consistency of a baked meringue or prawn chips, and are very easily damaged,” said Sabine Jessen, CPAWS National Ocean Program Director.

“Heavy fishing gear like bottom trawl nets and prawn traps can crush the delicate reefs, while the sediment plumes kicked up as equipment is dragged along the sea floor can smother and choke the sponges.”

“Tragically, we think about 50 per cent of the glass sponge reefs have already been destroyed by bottom trawlers and other heavy fishing gear,” adds Jessen.

All of these reefs would be extraordinarily vulnerable to seabed mining, see our article: The New Gold Rush: The Debate Over Deep Sea Mining, Part A .


Sea of Glass Marine Protected Area

glass sponge reef mpa british columbia living oceansConsequently, it was very welcome news to hear that the Sea of Glass had become Canada’s newest Marine Protected Area. Included in this area are reefs in the Hecate Strait and Queen Charlotte Sound.

“The glass sponge reefs are an international treasure, they are globally unique, incredibly important, and deserving of strong protection so that they can remain a source of awe and wonder for generations to come,” said Sabine Jessen CPAWS National Ocean Program Director.

See the entire article at CPAWS the Canadian Parks and Wilderness Society. Old friends and ocean allies.

By Robert Frerck, Blue Ocean Network


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