The first invasive European green crab in Ketchikan was found in 2025. The work to stop the spread is just beginning.

On a beautiful day in June 2025, members of a summer field class were soaking up some rare Southeast Alaska sunshine in the aptly named Refuge Cove. Led by professors Barbara Morgan and Charmaine Lewis as part of the Alaska Climate Adaptation Science Centerʼs inaugural Ambassador program, the University of Alaska Southeast class had spent the week combing the beaches of Ketchikan looking for a small invader that had been moving north and taking over the coastline. After a week of searching the mudflats, rocks and tide pools, they hadn’t found what they were looking for, and in this case, a week of nothing was exciting news.

But it was during this trip to Refuge Cove that Lewis and another student each found a fateful hollow crab shell belonging to a European green crab. At about one inch in diameter, these tiny shells of a rapidly spreading invasive species portended a huge shift for a community that depends on its vibrant marine ecosystem.

After the first two shells were found, the class had come to an end, but it was clear to Morgan and Lewis that the work was just beginning. Morgan took to social media and local newspapers, radio and TV to share about the findings. She urged others in the community to check the beaches. News spread quickly, and by the end of the summer, over 50 European green crabs had been located in the area.

Among those found were multiple fully grown crabs, making it clear the adult crabs had been in the Ketchikan area undetected for years.

“The class that the (Alaska) CASC funded for us with the Ambassadorʼs Program, has really prompted a much more immediate response here,” Morgan said “Theyʼd been here and we hadnʼt found them.”

European green crabs were first found in Alaska in 2022 on Annette Island, about 20 miles south of Ketchikan and home to the community of Metlakatla, but they had been a long time coming. Introduced to Northern California in 1989, European green crabs have been making their way north through a process called planktonic larval dispersal. Tiny crabs in the larval stage float with the northward currents to colonize new coastline, often making leaps and bounds in years with warm winters and a good northward current, the trademarks of an El Niño year.

With a native range of North Africa to Norway, they have an extremely wide temperature tolerance and are prolific reproducers – a female European Green Crab releases two to three egg capsules per year each carrying about 180,000 eggs.

The crabs are small, at 3.5 inches in diameter when fully grown, but they are voracious in their appetites, eating shellfish, juvenile Dungeness crabs and juvenile salmon. They are also relentless burrowers. As they dig into the sand and mud along the coast, the crabs disturb coastal eel grass habitats that are nursery ground for salmon and home to other important native species.

As the crabs keep moving north, communities are looking southward for answers. Washington State declared an emergency in 2022 to try to help contain the invasion, which had been devastating their shores and shellfish industry. The State of Washington now allocates $6 million each year, most of it going to local partners, to keep the populations under control.

In the spring of 2026, Ketchikan Indian Community, in partnership with the Native American Fish and Wildlife Society and Southeast Alaska Tribal Ocean Research, held a European green crab workshop. In attendance were members of Washington tribes Quinnalt, Makah, Lummi, Shole Water Bay, and Tulalip who have been dealing with European green crabs for years. The workshop was an opportunity for tribes to learn from each other how to best trap and collect the invasive crabs.

European green crabs have not been successfully eradicated from a North American coastline, but the best method to combat them is known as “early detection, rapid response.” In other words, a community must trap and remove as many European green crabs as soon as possible, striving for a functional eradication, especially in important or delicate habitats.

“Left unchecked, there would be millions on all the beaches,” Morgan said.

Soon after Morgan and Lewis’s discovery, the Ketchikan Indian Community sprang to action. Wildlife biologist Emily Halsell was directed to lead their European green crab program, and she began trapping as of October 2025. From May through September 2026, Halsell and her team had trapped about 7,000 European green crabs.

Lori Petrauski, technical assistance provider with the Native American Fish and Wildlife Society, experienced this firsthand at the spring workshop when the group took a boat ride from Ketchikan to Metlakatla. There she found tide pools overrun with the invasive crabs.

“I could understand why nothing else could survive,” Petrauski said. “They were everywhere. We could just scoop them up with our hands.”

European green crabs may just be in the southernmost parts of the state, but they are likely to keep moving north. Depending on the extent of ocean warming along Alaska’s coast, European green crabs could make it as far as the Bering Sea, devastating the economically and culturally important fisheries along the way.

Currently, as a Class A Invasive Banned Species, European green crab can only be collected, possessed or transported with a valid aquatic resource permit. Most of the European green crabs along Metlakatla and Ketchikan shores are currently trapped under the Ketchikan and Metlakatla Indian Communities’ trapping permits and are being used as compost. In other states, they’ve had some success eating the crabs and even turning them into whiskey.

Ketchikan and Metlakatla face a difficult, and likely never-ending, challenge to the stewardship of their marine resources, but they are not the first community to face it, and they are stepping up to the challenge together. Ketchikan’s response is already rooted in community. Halsell invites community members to join her trapping events. Homeowners have reached out to provide easier beach access to get to potential European green crab sites, and even the initial action after Morgan’s media appearances led to more rapid response.

Continued research may also be able to help. Scientists and modelers can predict where in Southeast Alaska European green crabs are likely to thrive and where those locations overlap with local food sources. This would help funnel limited trapping and monitoring resources to the most effective locations. And climate and ocean models can show just how far north the crabs may spread, giving northern Alaska communities a head start at understanding European green crab dynamics.

Halsell and Morgan also have an eye toward the rest of Southeast Alaska. Morgan is hoping to travel to Prince of Wales Island or north to Petersburg or Wrangell to help build identification and monitoring capacity.

And Halsell urges Southeast Alaska coastal communities to be proactive in their management, even if European green crabs haven’t been confirmed in the area.

“You won’t know if they’re there until you trap for them,” Halsell said.

In the meantime, Southeast Alaskans are tasked to look out for the invasive crab. European green crabs can be identified by their five spines or spikes on either side of their eyes. European green crabs are, surprisingly, not always green. Many native shore crabs are green, so they should not be identified by color.

If you think you’ve identified a European green crab, do not kill it or take it home. Possession and transport of banned invasive species is prohibited. Take photos of the crab from different angles, and with an identifiable object such as a coin, key or pencil to help show size. Please submit photos to Tammy Davis (tammy.davis@alaska.gov) or call 1-877-INVASIV.