A section of the glass sea sponge reef off of the coast of British Columbia. Photo courtesy Sally Leys, UAlberta.
On the "did you know" scale, it's arguable that most Canadians have no idea that our Pacific Coast is the only place in the world with glass sponge reefs. What's more, many likely don't even know that glass sponges exist. Until just 25 years ago, it was thought that the fragile glass structures had been extinct since the Jurassic Period 200,000 years ago. Now, these sea sponges are in danger of real extinction due to fishing practices off the coast of British Columbia. The threat to the ocean ecosystem is real and dangerous, as glass sea sponges act as a natural filtration system for ocean waters.
But a scientific mission set to start this week is dedicated to increasing both awareness and understanding of these rare 6000-year old reefs as well as protecting them for future generations. The mission will be livestreamed to anyone in the world with an internet connection. Viewers will also be able to ask questions and have them answered in real time by the scientists. The researchers will be working 24 hours a day on data collection, so long as a number of critical factors work in their favour, most notably, weather.
"It's hard to get there, and the weather could be terrible, but we have an obligation to collect data to protect these reefs from turning to rubble." -Sally Leys
The mission will take the scientists into deep and potentially choppy waters in the Banks Island area off of the British Columbia Coast. "It's hard to get there, and the weather could be terrible, but we have an obligation to collect data to protect these reefs from turning to rubble," says Sally Leys, University of Alberta professor, and scientific lead for the mission. Given the rarity of the reefs, it's unsurprising that Leys and her team are virtually the only scientists in the world with expertise on glass sponge reefs. She and her team traveled to the reefs in 2015 but were only able to collected data on one of 10 days due to inclement weather, forced to wait out the storms in the nearby fjords.
Air filtration system for the sea
Leys describes the biscotti-like sponges as a giant hidden air filtration system for the sea, sucking in water and filtering out bacteria and returning nutrients to sustain plankton, which in turn sustain fish. "They're a massive recycler of nutrients. The volume they recycle is unfathomable. One sponge alone filters 300,000 litres of water a day, and there's thousands of kilometres of sponges on that ocean floor. Without that recycling effect, nutrients aren't being replaced back in the water column."
The Hecate Strait and Queen Charlotte Sound Glass Sponge Reefs were recently designated by the Canadian Department of Fisheries and Oceans as a Marine Protected Area, but Leys says that's not enough to ensure the long-term sustainability of the sponges. She recently signed a letter in support of the Canadian Parks and Wilderness Society's proposal to have the area designated a World Heritage Site. "We have an opportunity now to protect these areas that we simply won't have in the future if things continue as there are. I feel a bit strange going to work in a Marine Protected Area, but on the other hand, Canadians need to know what we are protecting. We have to take these things seriously."
Reefs reduced to rubble
The current adaptive management zone around the core protected area is two kilometres, but Leys explains that sediment from trawling fishing boats can travel up to eight kilometres, re-suspending the sediment at three times the concentration that triggers the sponges to stop feeding. "Most sponges sneeze as a way to filter out sediment, but glass sponges don't do that. So if they bring in dirt, they hold their breath. If they filter out sediment, they'll clog. Even a week of not filtering could mean the death of the reef."
"Even a week of not filtering could mean the death of the reef." -Sally Leys
Leys says other reefs closer to Vancouver Island have been reduced to rubble by trawling fishing boats and sediment disruption. Glass sponges are unique in that they use electric signaling to communicate, acting as a giant cell. Leys says understanding how and why the glass sponges act in the way they do will allow exploration into the evolution of nervous systems.
The scientific mission will be dedicated to determine the functionality of the reef, to understand whether the current boundaries need to be expanded, and to propose an effective way to monitor the area to mitigate future disruption.