A shallower dip than usual for a handful of local freedivers is feeding into planning for a future program to manage the local European green crab invasion in Sooke Basin.
The basin is known for its huge green crab population – the largest in the area.
“Unfortunately, at that point, because it’s so big, we can’t do much about it,” said Chloe Kraemer, a program coordinator with Peninsula Streams and Shorelines Society. “We’re never going to fully eradicate them, which is not great.”
The environmental non-profit works to maintain and restore waterways and ecosystems across Greater Victoria. The out-of-control green crab population in Sooke inspires other early detection trapping programs in the region to track the spread of the species and attempt to keep it from bleeding into other areas.
A few months ago, a general conversation was had about how to take that trapping in a new direction.
The crabs are highly visible and scatter in the shallow waters in a way that they could just be scooped up. The more they talked, the more they came around to divers or snorkelers learning the ropes in proper identification and collection.
“We really just wanted to trial the method and see if it worked before we moved forward,” Kraemer said.
It led them to seek out a partner for a trial, easily finding one in Chris Adair with Bottom Dwellers Freediving, which is already a supporter of the non-profit.
Adair was already interested in something similar. His Victoria-based company offers classes from Victoria to Tofino in freediving and various underwater harvesting methods, as well as charters and myriad youth programs.
They have Warrior leadership programs throughout the Nuu-chah-nuth Nations working with youth on snorkel harvesting programs, creating or strengthening connections between youth and their in-water environment.
“Within those programs, there’s always that question of how to bring further learning. Who knows what fire you light in someone at a young age just introducing that option,” Adair said.
So, as the tide settled just right to reveal them on a warm September day, a handful of freedivers paired with Peninsula Streams and Oceans, a Fisheries Canada representative on hand, and took to the waters in a trial run at collecting European green crab.
First, the small team dove into the educational component of identification and collection before wading into Sooke waters. The line, with Kraemer wading closest to shore and six freedivers snorkelling, fanned out and combed the shoreline for about an hour.
“We were just picking up green crabs left, right and centre,” Kraemer said. “They were everywhere and super easy to spot, which was exciting and disheartening to see.”
The group saw native crabs – graceful and dungeness – in a low enough count to tabulate on one hand, and 84 of the invasive crabs alongside immeasurable lessons to develop into a comprehensive and informed catch program.
The crab were measured, sexed and documented, then frozen in accordance with DFO requirements. The crab will stay on ice for a week before heading for the landfill. They wanted to do it the right way, using an appropriate method to gain knowledge and feed into a scientific study.
“It was not only removing species and creating benefit that way, but learning more about removal methods and the impact we have with different removal methods,” Adair said.
Freediving is a sport on the rise, and with snorkelling more widely accessible, it’s even more popular, Adair said. And people want to help.
“Why not marry those things together and create a program where people can almost be certified in green crab removal,” Kraemer said.
The plan now is to explore funding, sponsorship and other opportunities in a bid to formalize a program that includes education on identification, habitat, behaviour and history. It’s critical folks don’t remove native crabs by accident.
“That teaching component is important. You do need a licence to remove green crab anyway,” Kraemer said.
The European green crab is present all the way up the West Coast, but that invasion has been going on for over two decades. First found on the East Coast in 1951 in the waters off New Brunswick, they have expanded to many locations in the Atlantic. In the west, the European green crab likely arrived in the late 1990s through larval transport.
They moved naturally, through larval drift, up the West Coast and were first reported on the U.S. side of the border in fall 2016, with subsequent discoveries in 2018. They remain sporadic on the Canadian side, according to the DFO.
They are found along the entire west coast of Vancouver Island with patchy distribution and documented sightings at places such as Witty’s Lagoon, Gorge Waterway, Sidney and Ladysmith.
“The goal and the hope is to cull those localized populations, using Sooke as an example of what we don’t want to happen,” she added.
While freedivers might generally prefer deeper water, all are generally ocean lovers and environmental enthusiasts who brought their expertise in safety and gear needed for the job.
“They saw new things and felt like they were making a dent into an invasive species that is impacting eel grass, clams and crabs,” Adair said.
“I think we have a very good idea of where we could go with it,” Adair said. “It felt so cohesive and natural. It was an amazing first go at it, and it’s only going to get better from there, I think.”
