One of Turza Humchitt’s earliest memories is of her grandmother’s table, where family sat on benches on either side and shared from a large pot that might hold soup, clams, cockles or Dungeness crab.

Fresh clams were steamed with rice, fried in the half-shell or eaten with broth sipped straight from the shell. For Humchitt, they still taste like childhood.

“It reminds me of what’s always been there,” Humchitt, a Heiltsuk community member who lives in Bella Bella, on B.C.’s central coast, said.

Now, that food is harder to find close to home. Humchitt said her husband has had to travel farther in recent years to harvest clams — thanks to an invasion hastened by a disaster.

A decade after the tugboat Nathan E. Stewart ran aground and spilled diesel into the nation’s clam harvesting areas, Heiltsuk guardians — trained Indigenous stewards who monitor the nation’s lands and waters — say the damage is still spreading. In Gale Creek, near Bella Bella, guardians have found European green crab populations have increased dramatically since the spill. 

European green crabs are native to Europe and North Africa, but have spread widely in North America. Unlike native Dungeness crabs and the larger blue crabs commonly eaten on the U.S. East Coast, green crabs are small and carry little meat. They are edible, but often more practical for stocks, sauces, fertilizer or other products than as a crab people crack and eat at the table, Carolyn Tepolt, an associate scientist at Woods Hole Oceanographic Institution, said.

Tepolt said green crabs are unusually well-suited to spread and survive in new places because they tolerate a wide range of conditions, eat many different foods and may be able to withstand some polluted environments. 

“If you were going to design a great invasive species, it would probably have a lot of the qualities the green crabs have,” Tepolt said.

Crews are removing the invasive crabs as they eat young clams and show up in more parts of Heiltsuk territory — threatening clam beds that have sustained Heiltsuk food, culture and livelihoods.

Diana Chan, natural resource manager with the Heiltsuk Integrated Resource Management Department, said the possibility that an oil spill could be followed years later by a green crab surge was not something the nation had initially been watching for.

When a spill happens, the response often focuses on containing and cleaning up the oil, Chan said. “The long-term monitoring has really been lacking,” she said. “Heiltsuk was left to just do all of it on our own.”

A surge in green crabs

Green crabs were present in Gale Creek before the spill, but in much smaller numbers. Guardians usually caught 10 to 20 crabs per trap and commercial clam harvesters killed crabs they found on the beaches.

A July 2026 report prepared by Chan and Milène Wiebe — a PhD candidate at the University of Alberta — and reviewed by Canada’s National Observer determined the spill was “likely a significant contributing cause” of the crab explosion that followed. Green crabs are highly resilient to pollution and environmental disturbance and may survive those impacts better than many native species, it says. The spill also closed the commercial clam fishery, meaning the usual 40 to 50 harvesters were no longer on Gale Creek beaches for weeks each winter, killing crabs as they worked and detecting changes early.

By 2019, three years after the spill, some traps were regularly catching more than 50 crabs. In one three-month stretch in 2024, Heiltsuk crews removed more than 32,500 green crabs from about 20 Gale Creek clam beaches.

To protect clam beds, Heiltsuk crews need to drive crab numbers down. But as trapping increased, Chan said crews also began watching for another risk: adult crabs eat their young and if too many adults are removed from a contained area, more young can survive as predation drops.

Researchers call that the “hydra effect.” Edwin Grosholz, a distinguished professor emeritus at UC Davis, led a study documenting it in Seadrift Lagoon, a small California estuary, after an intensive eradication effort cut adult green crabs by more than 90 per cent. Within a year, the population rebounded more than 30-fold, from fewer than 10,000 crabs to about 300,000.

“This kind of thing can happen where adult animals in the population consume or cannibalize the young,” said Grosholz, who has studied green crabs since their early spread along the West Coast in the 1990s. “If you remove most of the adults, then the juveniles are free to survive and then the population suddenly explodes.”

Chan said Heiltsuk has not seen signs of that happening in Gale Creek. But crews now use traps that can catch smaller crabs too, including minnow traps and prawn-style traps, so they can track whether juvenile numbers rise as adult numbers fall. 

Winter catches often drop because crabs are less active, so summer catch numbers offer a clearer measure of the trapping effort. “When we see the numbers remaining low in the summer, we take that as a sign that the trapping has been working,” Chan said.

What the crab boom is costing Heiltsuk

The Nathan E. Stewart spilled about 110,000 litres of diesel and other pollutants in October 2016, contaminating some of Heiltsuk’s most productive clam beds. Nearly 10 years later, Heiltsuk has settled with Kirby Corporation, the U.S.-based company connected to the vessel, but key questions about long-term restoration and compensation remain unanswered.

The First Nation says current green crab removal efforts fall far short of what is needed. The report estimates a large-scale green crab response would cost more than $22 million over six years. It calls for scaling up to 10 vessels on the water each day, with 30 full-time green crab removal positions and the goal of achieving “functional eradication” within five years — reducing green crab numbers enough that they no longer cause major harm, so clam populations can recover. 

In the sixth year, trapping would drop to one or two vessels a day to prevent another population surge and determine what level of control will be needed indefinitely.

Chan said Heiltsuk currently has one dedicated green crab crew, though in some years, when additional funding has been available, it has had two. The nation now has six full-time employees trapping green crabs, with 300 traps deployed across the territory.

Gale Creek alone has more than 20 clam beaches. Crews can usually set about 40 traps a day, meaning they can only focus on a few beaches at a time. Some beaches are also difficult to reach because of the tides, Chan said.

The trapping effort has also had to account for other wildlife. Researchers have documented coastal wolves pulling up submerged crab traps to steal bait. Chan said crews now use only herring after wolves were drawn to traps baited with sea lions.

Heiltsuk has seen what it takes to make a dent. On one small beach in Gale Creek, crews trapped so intensely over the summer that crab numbers dropped and stayed lower than nearby areas. But the success was tightly contained: just metres away, traps were still pulling up 60 to 100 green crabs, Chan said. 

That makes the work a balancing act: crews need to trap hard in Gale Creek while also watching nearby areas where green crabs are appearing in smaller numbers.

The green crab response is also reshaping the guardian program. William Housty, director of the Heiltsuk Integrated Resource Management Department, said crews with limited capacity are being pulled between protecting clam beds and monitoring salmon habitat, shellfish safety, fisheries, wildlife and other species across Heiltsuk territory.

“It puts us in a really difficult spot to have to choose which is more important because they’re all very important for us,” Housty said. 

Chan said adult Manila clams are still present on some Gale Creek beaches, but juvenile clams have declined sharply. That means today’s adult clams may not be replaced as they die. “It’s really the smaller clams that are most vulnerable to the green crab,” Chan said. “That’s why we can go to beaches here and still find lots of adult clams, but not the babies.”

Housty said Gale Creek was known for “football fields” of clam beds and once supported a commercial Manila clam fishery that employed 30 to 40 people, along with shore workers. 

For Heiltsuk, clams are not only a commercial resource. Marilyn Slett, chief councillor of the Heiltsuk Nation, said they are a staple food, a winter economy and part of community life. Families harvest them, jar them, preserve them and serve them at potlatches and feasts.

“Our people rely on the ocean for our sustenance,” Slett said. “Clams [are] one of those keystone species that we rely on.”

Possible uses for green crabs

The crabs now being removed from Heiltsuk waters are frozen and taken to Bella Bella’s composting facility, where they are mixed with household compost for community use. The Heiltsuk are also exploring whether they could be used for food, fertilizer or bioplastics.

Chan said she is aware green crabs are eaten in some parts of the world, especially as soft-shell crab, but she has not heard of people eating them locally. The nation is in early discussions with Fisheries and Oceans Canada about whether green crabs removed from Heiltsuk waters could be put to use rather than discarded.

Across the coast, other Nations are also looking for incentives that could make green crab removal more useful.

Gaagwiis Jason Alsop, president of the Haida Nation, said their crews have been monitoring and removing green crabs as the species spreads into Haida Gwaii. But the work takes consistent labour and funding, while the crabs keep reproducing. Without a practical use for them, every crab pulled from the water remains a cost with no direct benefit.

“They are a challenging species to get control of,” Alsop said. “They are prolific. And I think we’re seeing that you kind of need some economic incentive, something you could do with them, that would hopefully motivate people to catch them and help keep their numbers under control.”

Hasheukumiss, also known as Richard George, hereditary chief of Ahousaht First Nation on the west coast of Vancouver Island, said he has pushed for green crabs removed from local waters to be used as food instead of treated only as waste. He said he and his mother experimented with cooking green crabs in a bisque and found them “very delicious.”

“There’s no reason why the government can’t sign a piece of paper over to myself and my nation to do good for the island and the mainland as well,” George said.

The department is developing a regulatory process for proposals to use European green crabs for purposes other than disposal, Renny Talbot, a senior fisheries protection biologist with Fisheries and Oceans Canada, told Canada’s National Observer. He said the department may be able to issue licences that allow people involved in green crab control to use or sell the harvested crabs, but said that would still be part of an invasive species response, not a commercial fishery. Fisheries and Oceans Canada would regulate the licence for catching the crabs, he said, but if they were used as food, harvesters would also need to work with other authorities, including the Canadian Food Inspection Agency and the province, on processing and food requirements.

“We don’t want to have it as a sustainable fishery. We want them gone,” Talbot said.

Talbot said European green crabs were first found on the west coast of Vancouver Island in the late 1990s and have continued moving north through ocean currents. They are now present on the west coast of Vancouver Island, parts of B.C.’s central coast and Haida Gwaii. Green crabs are Fisheries and Oceans Canada’s top marine invasive species priority and the department is working with Indigenous partners on management plans that focus removal efforts on key habitats and culturally important areas, he said, noting that the department expects to update Heiltsuk on alternative uses for green crab by the end of the year.

That might help the Heiltsuk in the future, Housty said. But it does not eliminate the need for a larger removal and restoration program now, as every season without enough trapping leaves the next generation of clams exposed.

Slett said the 2016 oil spill helped galvanize coastal opposition to oil tanker traffic. Nearly 10 years later, she said, Heiltsuk is still dealing with the consequences of that spill, even as governments continue to discuss major projects and marine shipping on B.C.’s north coast.

“That’s one of the reasons why we pursued upholding the tanker ban so hard,” Slett said. “It’s our lived experience with the Nathan E. Stewart and knowing that it’s still unresolved.”

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