Science talk to focus on Dungeness crabs

Published 1:30 am Thursday, March 26, 2026

PORT TOWNSEND — A lecture on scientific efforts to better inform fisheries on setting Dungeness Crab numbers will take place at Fort Worden this weekend.

The event is the last of the winter Future of Oceans lecture series presented by the Port Townsend Marine Science Center.

The free lecture will be at 3 p.m. March 29 at Fort Worden’s Wheeler Theater, 25 Eisenhower Ave.

Speaker Emily Buckner, program manager of the Pacific Northwest Crab Research Group (PCRG), said her talk will cover a little bit about biology, the ecology of the species and how the fishery is managed.

Dungeness crab populations, which are robust in many places, also have diminished notably in other spots, which is baffling, she said. As a whole, the populations seem to be stable, Buckner added.

“I think a lot of the time in natural resource management, we don’t pay a ton of attention to something until it’s almost gone or it’s in crisis,” Buckner said. “Our goal with Dungeness crab is not to let that happen. It’s to try to really build a better understanding of the species while it’s still doing well so that we can protect it and keep the fisheries as sustainable as we can, long term.”

PCRG is a network of state, tribal, federal and nonprofit partners who hope to build a meaningful database that may one day be used to make data-based decisions on crab limits.

Buckner’s lecture also will touch on the power that collaborative relationships can have in research.

The crabs, most known for their place in cuisine, are thought to be about 4 years old when they reach their mature adult size of 6.25 inches, at which they can legally be kept.

Populations can be found as far south as the Baja California peninsula in Mexico and as far north as Alaska, Buckner said.

Reduced numbers in some specific areas may be due to overcrabbing, warming waters, or it could just be the natural ebb and flow of the populations.

Tracking underwater species is a challenging proposal, Buckner said. The best that scientists can do is make experiments from which they can reasonably extrapolate their population estimations, she added.

One survey method involves light traps.

“The light traps are these sampling devices that are literally like 5-gallon water jugs with mesh at the bottom and funnels in the side,” Buckner said. “We put LED lights in the middle that turn on at night, and they attract larval crab into them.”

Surveyors count the number caught in the morning. Over time, patterns in the data set may shape the way keep limits are set for the crabs.

“We’re still in the data-building stage and trying to see if our light larval crab numbers line up with adult crab catches fairly well,” Buckner said. “We’re not making formal recommendations to managers yet.”

PCRG has about 20 light traps placed around Washington waters, Buckner said.

The light trap experiment was first used to track Dungeness crab by University of Oregon biologist Alan Shanks in the 1990s.

After hatching, during the plankton phase, the larvae spend months floating in the ocean currents. In spring and summer, they shift from floating plankton to seafloor dwellers. During that stage, they are attracted to light, hence the effectiveness of the light traps.

As juveniles, the crabs hide in complex habitats like eelgrass and oyster reefs to find food and avoid predators. By the age of 2, the adult crabs move into deeper waters.

“They eat dead stuff,” Buckner said. “Crab are really, really good at eating basically everything on the seafloor. They will move around in search of food. I’ve had many commercial fishermen tell me that, in the years that there’s big salmon runs, that you can find tons of crab at the mouth of big rivers because they’re feeding off of the carcasses of salmon that have been washed back out after spawning.”

The crabs have very few natural predators, aside from humans, octopus, some large fish and otters, Buckner said.

“They have a hard shell, they have big, strong claws, and they are kind of marching around on the seafloor just cleaning things up, eating whatever they can,” Buckner said.

Somehow, the crabs still taste delicious, she said.

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Reporter Elijah Sussman can be reached by email at elijah.sussman@peninsuladailynews.com.