The sun was bright and the wind strong last Sunday as a group of recreational divers cruised across choppy waters to the middle of Dorman Bay to sink into its depths and explore a rare and prehistoric Glass Sponge reef. The group, which included Bowen Island resident Adam Taylor, are all avid divers who are admittedly hooked on their sport, so last weekend's journey was much about the thrill of seeing life underwater. However, the divers also set out to document their expedition in the hopes they can prove the reef is worthy of protection.
"We're worried that the reef will be destroyed before we even learn anything about it," says Taylor.
Two years ago, he encouraged fellow diver and explorer Glen Dennison to explore Dorman Bay with his depth-sounder.
"My Dad used to tell me stories about, when he was a kid in the late 30s, early 40s, he used to sit on a rock overlooking Dorman Bay and watch these old Portuguese fishermen who'd rowed over from Whitecliff and they'd be handlining without rods, very large, mature Yelloweye Rockfish. The way he described it was that the fish were bigger than the five gallon pails the fishermen were throwing them in. So, that would be a substantial fish that would probably be a hundred, a hundred and fifty years old at the time."
Knowing that in his exploration of other Glass Sponge reefs in Howe Sound, Dennison noted an abundance of Rockfish, Taylor thought there just might be a reef in Dorman Bay.
Dennison has spent five years charting the waters of Howe Sound in his boat, The Skyliner, guided by a depth-sounder and a computer system that he uses to chart the under-water geography. He's found seven of the nine known sponge reefs in the area. Many of these sit at a depth of 150 or 250 feet below sea-level, which is well beyond the limits of the recreational diving. Given these circumstances, Dennison has conducted much of his exploration with a a drop-camera he built and design himself (he's an electrical engineer). With this, he has acquired hours of video footage of the deep-water reefs and the life that gravitates towards them.
After Dennison located what he thought was a reef in Dorman Bay, he and Taylor headed out for a dive.
"What we found was not simply a coral garden," says Taylor. "It's a whole bioherm, and it appeared to be about the size of the General Store."
Taylor says a coral garden is made up of sponge growing on a rock, whereas a bioherm is living sponge growing on top of a dead sponge. As the sponge grows, the currents shift around it causing sedimentation at the base which slowly smothers and kills the bottom portion, but the skeletal remains support the new growth above.
"From the limited research that has been done," says Taylor, "we know that these [coral gardens and bioherms] are two very different habitats. A coral garden will have a much greater diversity of species than a bioherm, but a bioherm will have a much greater density of life, but with just a few different species represented."
Taylor says the Glass Sponge Bioherms could be hundreds, or even thousands of years old.
Ask Dennison about what they found in Dorman Bay and he'll launch into details.
"It's called Aphrocallistes vastus, and the common name is Cloud Sponge," he says, explaining that Cloud Sponge is a kind of Glass Sponge, a rare, prehistoric species found only off the coast of British Columbia. Different Glass Sponges are different colours. The Basket Sponge near Passage Island, for example, is bright orange in colour. At Dorman point, the Cloud Sponge is bright white.
These sponges filter huge amount of water, says Dennison.
"A bioherm like the Galleano Ridge out in the Georgia Straight there, they'll be running 90 thousand litres a second through them. They're having an effect on the water purity and they may be coliform chewers too so, coming off the sewer plant, its great we got sponges!"
The divers were excited to find the reef in Dorman Bay, but they also saw cause for concern: a large hole, probably caused by a prawn or a crab trap.
Taylor and Dennison wanted to make a second dive to gather general information this sponge, but also to check out this hole again and determine there was further damage to the reef.
The challenge of this particular exploration is that the reef, at its top, sits at 36 metres (120 feet) below sea-level. A typical recreational dive involves a descent of between 24 to 30 metres (80 to 100 feet). The deeper the diver goes, the higher the pressure of the air entering his or her lungs. As the diver stays at a certain depth, nitrogen is released into his or her body. To ensure that the nitrogen causes no ill effects, the diver needs to rise back up to the surface slowly, making stops to "decompress" on the way up. The crew on last Sunday's dive determined they could stay at the depth of the reef for a maximum of ten minutes.
For the dive, Taylor buddied up with Diane Reid, an avid diver and photographer who lives in East Vancouver. They geared up in their dry suits and dropped off the back of the boat first, followed by Dennison and David Park.
Upon returning to the boat some 20 minutes later, all the divers reported to clear waters offering great view of the sponge. Taylor and Reid saw plenty of juvenile Rockfish, galatheid crabs, hundreds of squat lobster, Vermillion stars, Blood stars and lots of perch, and a single Dungeness crab, but no damaged area on the sponge.
Dennison however, was able to find the damaged spot, which he described as a "cookie-cutter hole."
"When we first saw it, the bottom of the hole was covered in live sponge, and the walls were all live sponge, but today, everything was dead."
He also says he saw what appears to be a far greater expanse of dead sponge then he saw on the first dive.
"My feeling is that it's caused by temperature changes down there, but there's so little known about Glass Sponges and the environment down there that its hard to say."
Both Taylor and Dennison were encouraged by the number of juvenile Rockfish they saw inside the sponge.
"There were five, possibly six different species of juvenile and sub-adult rockfish in the reef," says Taylor. "In those conditions it can be difficult to tell the difference between them, but the confirmed species were Quillback, Puget Sound, Yelloweye and Yellow Tail. I'd say that some of those will be a catchable size in 5 or 10 years."
Dennison says that in his exploration of other sponges, he's seen numerous pregnant Rockfish and he thinks the sponge might act as a nursery habitat for them.
"Rockfish give birth to live young," he says, "and usually they don't reproduce until they are at least 15 years old. So if we are going to support this population, its critical that we protect the young until they are at least old enough to start reproducing."
In the same way that Dennison shares his drop-camera videos with researchers at the Vancouver Aquarium to study, the divers will pass on their photos and observations from the expedition to the Dorman bioherm.
Taylor says he plans on putting together a roundtable discussion with various scientific groups as well as politicians from different levels of government to discuss the Sponge reefs in Howe Sound.
"We want to know what we, as the dive community can do to support researchers because there's a lot of ground to cover. And right now, the scientific community doesn't have the manpower or the funding to do it themselves. So, what could we do in terms of gathering information about how much life exists in these sponges so we can establish a baseline to compare what might exist there in the future."
Taylor says the the bioherm off Dorman Point is close enough to Bowen Island to fall within the jurisdiction of the municipal government, and it is close enough to Crippen Park that it could be included as part of it, and then, be relevant to Metro Parks.
"We want to start talking with local levels of government, including the Islands Trust, to find a way to protect this unique habitat. We're hoping that by working with the lower-levels of government we can put pressure on the higher levels, and eventually maybe create some kind of Marine Protected Zone here."
While the fishing of Lingcod and Rockfish is currently prohibited in Howe Sound, Taylor would like to see all forms of fishing, including prawning and crabbing made illegal in areas where there are known glass sponges.
"I don't know who said it," says Taylor, "but I heard someone say once, that Glass Sponge Reefs have such high habitat values that trawling through one would be like cutting down a rainforest to get to the squirrels."
