Chatham Sound Glass Sponge Reefs
About the mission
Our scientists dove deep from August 16 to 23, 2017 to study the recently discovered Chatham Sound glass sponge reefs aboard the CCGS Vector. These reefs have remained largely unexplored since their discovery in 2012 by an industry survey team and are believed to be one of the oldest sponge reefs known to date.
Located off the coast of British Columbia at depths of 30 to 180 meters below-sea-level, the geological extent of the reefs was recently mapped by Natural Resources Canada using remote sensing. Their findings suggest the reefs cover approximately 48 km2 of seafloor. However, this or any other remote sensing technique available to date cannot differentiate between live, dead, and buried patches of sponges, which makes this mission all the more important to help us better understand these reefs and their ecological significance.
The reefs were explored using a Phantom Remotely Operated Vehicle (ROV). The Phantom ROV gathered information on the size and health of the sponges, as well as the ecosystems they support. In collaboration with researchers from the University of Victoria, our scientists placeed hydrophones on and near the reef to record acoustic signals, which was used to assess the health of these deep water ecosystems.
About glass sponge reefs
Glass sponge reefs, once thought to be extinct worldwide, provide refuge, habitat, and nursery grounds for many aquatic species. Reef-forming glass sponges are long-lived, but slow growing and exceptionally fragile with skeletons made of silica or glass. Their growth rates are estimated at 1 to 9 cm per year and, as a result, the reefs are known to have low recovery rates from disturbances. Mechanical injuries, such as crushing, also damage the framework of the reef and its ability to grow, while increased sedimentation can impact the living portion of the reef.
About the area
The Chatham Sound glass sponge reefs are located off the northwest coast of British Columbia, in the Northern Shelf bioregion of the Pacific Ocean near Prince Rupert.
The research team
- Dr. Anya Dunham – Chief scientist
- Dr. Stephanie Archer – NSERC Postdoctoral visiting fellow
- James Pegg – Technician, ROV pilot and data manager
- Wolfgang Carolsfeld – Technician, ROV pilot
- Lily Burke – Biologist
- Dr. Emily Rubidge – Research Scientist
- Amalis Riera - University of Victoria
Research tools and techniques
Remotely Operated Vehicles (ROVs) are tethered, unmanned underwater vehicles used to collect footage and samples from the seafloor. Manually controlled by researchers from shipboard computers, they are outfitted with high definition cameras, lights, and other features such as motorized arms that can grab samples. Highly maneuverable, ROVs can also withstand the pressure of being thousands of meters below sea-level. The visual data ROVs gather provide insights into biodiversity abundance, species interaction, and behaviour of aquatic species.
The Phantom ROV used for this particular mission can work at a depth of up to 600 meters and collect high definition footage and samples from precise locations.
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