[UW Today]: Invasive green crab found at Dungeness Spit

from UW Today, April 26, 2017, “Invasive green crab found at Dungeness Spit”

A European green crab found at Dungeness Spit, Sequim, this month.

A new population of invasive European green crab has been found at Dungeness Spit, near Sequim, Washington, rekindling concern over the potential for damage to local marine life and shorelines.

The first discovery of this globally damaging invasive crab in Washington’s Salish Sea was made by Crab Team volunteers last August on San Juan Island, followed quickly by a detection at the Padilla Bay National Estuarine Research Reserve, near Mt. Vernon. In both cases, rapid-response trapping and removal by a joint-agency team showed that the crabs were present, but still very rare in those locations.Staff and volunteers from U.S. Fish and Wildlife Service, which manages Dungeness Spit National Wildlife Refuge, captured a total of 13 European green crab over the past two weeks as part of the UW-based Washington Sea Grant Crab Team early detection program. These numbers indicate that the invasive crabs are more abundant at Dungeness Spit than at the two other known locations in Washington’s inland waters.

“This is a very different situation,” said Crab Team program coordinator Emily Grason. “In Padilla Bay, the crabs we found were too far apart to find and mate with each other, but at Dungeness Spit, multiple crabs are being found at the same site, over successive days of trapping. This indicates a situation where the population could grow very quickly, if we don’t intervene.”

read the full story at UW Today


[Tide Bites] Red rock crabs: the Dungeness’ grouchy cousins

This article comes from “Tide Bites”, the monthly newsletter of UW Friday Harbor Laboratories. “Red rock crabs: the Dungeness’ grouchy cousins” by Sylvia Yamada and Scott Groth: read the full article at the FHL website.

Adult crabs that were trapped under the FHL docks for the mark-recapture study.

Native red rock crabs (Cancer productus) are important predators on protected rocky nearshore communities from Alaska to Baja California. While they are harvested recreationally, they have not been as well studied as their commercially-valuable cousin, the Dungeness crab. Red rock crabs are abundant on semi-protected rock and boulder beaches where the substrate is composed of sand and shell gravel and where the salinity remains high. They have voracious appetites, feeding on a wide variety of species including barnacles, mussels, clams, oysters, snails, worms and sea cucumbers. Adults are highly mobile and are known to move into the high intertidal during flood tides to forage. We decided to piece together the life cycle of the red rock crab by compiling what was learned through various studies carried out on different life stages at Friday Harbor Laboratories.

[read the full article]