Sponge reefs | Marine planning and conservation | Oceans | Science & policy | Marine planning and conservation | Issues
Photo: Sponge reefs

Glass sponge reefs found in PNCIMA cover an area about seven times the size of Vancouver. (Credit: Natural Resources Canada)

Welcome to the sponge reefs page of the 'I Am Fish' tour. These three guiding words, I am fish, appear simple. But they reflect an ancient and extraordinary web of biological activity that connects humans with the ocean.

I am sponge

On the seafloor of the Pacific North Coast Integrated Management Area (PNCIMA), there are four large areas identified as glass sponge reefs. Combined they cover over 700 km2, or an area about seven times the size of Vancouver.

Exactly why these 9,000-year-old reefs are found here and few other places on the planet is not fully understood. It is likely a combination of factors including geology, ocean chemistry and ocean currents. The reefs provide a complex, three-dimensional habitat on a seafloor that is otherwise flat. As a result, many species of rockfish and other fish are found near the sponge reefs.

Why are the sponge reefs important to humans?

Egypt's oldest known pyramid were completed about 4,500 years ago, making them half the estimated age of the sponge reefs. While many of us have never visited the pyramids, we don't need to see them ourselves to recognize their historic value to all of humanity. Similarly, the glass sponge reefs are a biological wonder that have intrinsic value simply by virtue of their presence on the planet.

What can we do to protect them?

The sponge reefs are highly sensitive to any type of physical disturbance, including that caused by fishing gear or cable laying. Traditionally, these reefs have been most vulnerable to the impacts of bottom trawling, however a 2006 trawl closure around the reefs has effectively managed this threat. Aside from the four main sponge reefs, most of the seafloor of PNCIMA is unprotected from destructive fishing practices and other physical impacts.

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> Previous destination: Bottom feeders

http://www.davidsuzuki.org/issues/oceans/science/marine-planning-and-conservation/sponge-reefs/

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