06_2025_REELLIFE_digital - Flipbook - Page 37
How to identify invasive European green crabs and what to
do if you encounter them
By Washington Department of Fish and Wildlife
If you fish, boat, crab, or just
read the news in Western
Washington, by now you’ve
probably heard about
the invasive European
green crab. But how to
identify this green menace,
what are the rules if you
encounter one, and what
is the state doing about
them? Read on for answers
as well as tips to avoid
spreading these and other
aquatic invasive species.
Native to western Europe
from the Baltic Sea to
Morocco, the European
green crab is a damaging
crab that threatens
native shellfish, estuary
habitats, eelgrass, the
aquaculture industry,
and other recreational,
tribal, economic, and
environmental values. The
European green crab first
became established in the
United States in the mid1800s, arriving by ship to
New England, where they
contributed to dramatic
declines in the soft-shell
clam fishery.
Studies have shown these
voracious shore crabs
(meaning they live in
shallow, often intertidal
waters, including bays,
inlets, sloughs, and
estuaries) can consume
as many as 40 clams
a day! In areas where
European green crabs
have established large
populations for extended
periods, they have had
dramatic impacts on other
species, particularly smaller
shore crabs, clams, and
small oysters.
In addition to preying
on shellfish, European
green crabs are vigorous
diggers and have severely
harmed New England’s
eelgrass beds and estuaries.
If allowed to do the
same here in the Pacific
Northwest, loss of estuary
and eelgrass habitat would
threaten the harvest of
wild shellfish like geoducks
and cockles, undermine
shellfish businesses, hurt
salmon and forage fish
recovery, and disrupt
complex native food webs.
Research is also ongoing
regarding potential impacts
on juvenile Dungeness crab
and crab fisheries.
Back to Washington state,
European green crabs were
first discovered on our
coast in 1998 in Willapa Bay,
remaining in small numbers
but slowly spreading north
over the following decades.
European green crabs
were first documented in
Washington’s inland waters
in the San Juan Islands in
2016, and were confirmed
near Victoria, British
Columbia the previous year.
