Haida Gwaii oceans project tracks alien invaders

Haida Gwaii’s monitoring program for invasive marine species got a big boost this year.

  • Nov. 16, 2016 6:00 p.m.

When even your closest followers call you ‘rock vomit,’ it’s a good sign you’re unwanted.

Also known as the “carpet sea squirt,” Didemnum vexillum is a spineless, sea floor-smothering animal an invasive tunicate that can overgrow scallops, mussels, and other creatures.

Native to Japan, D. vex has spread around the world, blanketing fishing grounds in places like Cape Cod. In 2010, it was the first invasive tunicate found in Sitka, Alaska.

Biologists are now watching closely to see if D. vex spreads to Haida Gwaii, and also trying to learn more about two other invasive tunicates and other ‘fouling organisms’ that are already here.

Starting with a handful of sites in 2014, Haida Gwaii’s monitoring program for invasive marine species got a big boost this year, expanding to 90 test plates at nine sites across the islands.

“We’re really well covered,” says Stu Crawford, a biologist with the Council of the Haida Nation, noting that the program is a joint effort by the CHN, Gwaii Haanas, and Fisheries and Oceans Canada (DFO).

“Because of this three-way collaboration, we’ve probably got half the sites in B.C.,” he said.

In October, the Haida Gwaii program was joined by two experts from the U.S. Smithsonian Institute, which pioneered the test-plate method.

“It’s pretty high-tech science,” joked Linda McCann, a Smithsonian biologist who spoke at both Haida Gwaii high schools and an ‘Aliens Among Us’ talk in Masset.

Each test plates is a square of plastic weighed down by a brick, she said. Researchers sink them one metre underwater, wait three months, then haul them up to see what’s growing on.

Some plates get encrusted by a single species near Vancouver, many are completely covered in mussels.

One plate recovered from Masset Inlet last month had both of the invasive tunicate species that have covered Haida Gwaii docks and rocks in recent years. Of the 30 alien marine species in local waters, the two tunicates are a major concern.

One is the violet or chain tunicate (Botrylloides violaceus). Growing in purple, pink, yellow, white or orange colonies, it has buds that form long rows or chains.

The other is the golden star tunicate (Botryllus schlosseri), another colony-forming species that is usually two-tone black and brown, or orange and green. Its buds form a starburst pattern.

McCann said the trouble with invasive tunicates is that they can blanket large areas of seafloor, and are highly adaptable.

“They live basically everywhere you can imagine in the oceans, from the deep sea to the nearshore coastal waters, in marsh habitats and intertidal areas, or kelp forests,” she said.

“You name it, they’re there.”

Structures such boat and barge hulls, docks, buoys, and pier pilings are also welcome habitat to tunicates, she said, and once established, they can even spread on eelgrass and algae.

To better identify invasive tunicates and other fouling organisms, McCann said researchers are building a huge database of DNA sequences.

“Basically, we’re bar-coding everything,” she said.

“One of the things we’re doing now is taking a whole plate, scraping it all into one container, and running whole panels of DNA. But in order to make sense of the millions of sequences that come out of that, you have to have a database of all the sequences that you know.”

Vanessa Hodes, an aquatic researcher with DFO, said compared with visual identification, which is painstaking, DNA analysis is like a magic button. But it’s also a costly one.

Worldwide, the cost of managing all invasive species is somewhere on the order of $1.4 trillion.

One of the costliest is the zebra mussel, which spread to the Great Lakes in the ballast of a single ship.

Another is the European green crab, which was introduced to the East Coast over 100 years ago and began spreading up the West Coast in the last two decades.

Hodes said green crab are already well established near Sooke, Quatsino, and Ucluelet on Vancouver Island, where they eat or compete with juvenile Dungeness crab, but fail to outcompete the tougher Red Rock crabs.

“I trapped Barkley Sound in the summer,” she said. “Every trap was full of green crab.”

So far, green crab have not been seen on Haida Gwaii, nor in the Strait of Georgia where much of B.C.’s aquaculture is. But they spread quickly across the west coast of Vancouver Island during the warm El Nino of 2001.

Once they round the corner, Hodes said green grab will most likely establish themselves in the Strait, with unknown consequences.

McCann and Hodes said people can do to stop the spread of invasive tunicates and other marine species, starting with learning what they look like.

Boat owners can clean their vessels before moving them. The easiest way to get tunicates and other creatures out of all the nooks and crannies is to let the boat dry on land for a few weeks.

New regulations allow DFO officers to stop boats and ships from launching if they are harbouring fouling organisms.

Aquarium owners can help by not dumping their unwanted creatures into the sea, but giving them away to friends or otherwise disposing of them on land.

Anyone who sees an odd marine creature along the Haida Gwaii coast can help by calling local biologists such as Stu Crawford (250-626-3302). DFO also has an aquatic invasive species line at 1-888-356-7525.

On a larger scale, McCann said researchers are testing ways to treat ships’ ballast water. In Sitka, divers are now testing chlorine, cement dust, and heavy concentrations of salt on enclosures full of invasive D. vex.

McCann encouraged anyone who sees what they think is a marine invasive species to photograph it if they can, and take notes on where it was found.

Correction — This article has been corrected to reflect the fact that green crab eat or compete with juvenile Dungeness crab rather than ‘kill’ them. Also, while it’s likely green crab may become more established in the Strait of Georgia once they round Vancouver Island, the consequences of that change are still unknown. The original article implied a much more dramatic invasion than is expected.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

FILE - Nathan Cullen speaks to media in Smithers, B.C., Friday, February 28, 2020. THE CANADIAN PRESS/Jonathan Hayward
More calls come in for Cullen’s removal as NDP candidate

Gitxsan Hereditary Chiefs demand Cullen’s removal. Ellis says, There’s no place in B.C. for racism

BC Liberal Party candidate for the North Coast Roy Jones Jr. will hold virtual face-to-face meetings for North Coast communities on Oct. 18. (Photo: K-J Millar/The Northern View)
BC Liberal Candidate Roy Jones Jr, will meet constituents virtually

Face to face conversations will be held on Oct. 18 for North Coast communities

Kelly Lynn Whitney has been acclaimed as the successful candidate on Oct. 16, in the Village of Port Clements by Election. Seen in photos Kelly Whitney-Gould is pictured putting finishing touches on “Ms. Gnomer’s Home 4 Wayward Folk.” (Kelly Whitney-Gould/Submitted photo)
Kelly Lynn Whitney acclaimed in By Election

Village of Port Clements By Election success

Stikine provincial election candidates (clockwise from top left): Nathan Cullen, NDP; Darcy Repen, Rural BC Party; Rod Taylor, Christian Heritage; and Gordon Sebastian, BC Liberals.
‘Where is Annita McPhee?’: Cullen under fire from opening salvo of all-candidates forum

Four Stikine candidates spar during online debate from Prestige Hudson Bay Lodge in Smithers

Conservative member of Parliament Pierre Poilievre speaks during a press conference on Parliament Hill in Ottawa on October 19, 2020. THE CANADIAN PRESS/Sean Kilpatrick
Liberals say Tory effort to set up COVID-19 committee will be a confidence matter

The Tories were originally proposing an ‘anticorruption’ committee

Investigators work at the Sagmoen farm in Silver Creek. - Image credit: Observer file photo.
Sex workers allegedly called to farm of Okanagan man convicted of assault, RCMP investigating

Curtis Sagmoen, convicted in relation to assault of sex trade workers, is prohibited from soliciting escorts

(Black Press Media files)
Early voters more likely to favour NDP, but overall B.C. election is tightening: poll

According to Elections BC, 383,477 people cast a ballot during advanced voting days

Wave of racist emails ‘unleashed’ on B.C. researchers investigating racism in health care

The team has received close to 600 calls and emails since the investigation started in July

With local MLA Adam Olsen looking on, BC Greens leader Sonia Furstenau said a Green government would convert BC Ferries into a Crown corporation Wolf Depner/News Staff)
Green leader Sonia Furstenau promises to convert BC Ferries back into Crown corporation

Promise comes Monday afternoon with five days left in campaign

A passer-by walks past a COVID-19 testing clinic in Montreal, Friday, Oct. 16, 2020. THE CANADIAN PRESS/Ryan Remiorz
Canada ‘yet to see’ deaths due to recent COVID surge as cases hit 200,000

Much of the increase in case numbers can be attributed to Ontario and Quebec

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Police confirm human remains were found in a recycling bin in Vancouver on Oct. 18, 2020. (Black Press Media file photo)
Human remains found in recycling bin floating near Vancouver beach

Police asking nearby residents to see if their recycling bin has gone missing

The BC Ferries vessel the Queen of Oak Bay. (News Bulletin file photo)
‘Buy a boat,’ Horgan advises anti-maskers on BC Ferries

NDP leader John Horgan talks COVID-19 misinformation

Most Read