What is a Green Crab?
Green crabs, also commonly referred to as shore crabs, are a highly invasive species of small crab native to the northeast Atlantic Ocean and Baltic Sea. They have been present in the Gulf of Maine for over a century and it is believed that they made their way to North America in the mid-1800s after riding across the Atlantic in the ballast water on ships.
Green crabs are very effective predators, preying on many species including clams, oysters, snails, and even other crabs, to name just a few of their favorite snacks. They’ve been known to eat as many as 40 clams a day. Not only are they eating up a ton of the resources in the Gulf of Maine, but they also out compete other native species for food in these areas.
Where do Green Crabs Live?
Part of what makes green crabs so dangerous is their ability to adapt to many different habitats. They are able to tolerate a wide range of temperatures and water salinity. You can find them in marshes, tide pools, sandflats, rocky shores and many other places as well. You may also have luck looking near eelgrass beds or near other shoreline vegetation.
How to Identify Green Crabs?
Green crabs are not always green! Sometimes they may appear more yellow, brown, or even orange and red. The best way to identify green crabs is by the shape of their shell. A green crab will have five spines behind each of its eyes on the side of the shell. An easy way to remember this is that it spells out green G-R-E-E-N. Another identifying feature of green crabs is the three humps between their eyes.
What Should You Do if You Find a Green Crab?
If you find a green crab outside of its native region, don’t throw it back alive! They can be used for bait, or brought home to cook! You can find some delicious green crab recipes here!
Recently there have been confirmed sightings of green crabs in Alaska and they are being closely monitored. If you find one there, put the crab in a container with the date and location of where you found it. Freeze or preserve it with rubbing alcohol and call 1-877-INVASIV to report it. You can call this number to learn more about citizen based invasive species monitoring.