Hot Topic! Green Crabs


Introducing the Vital Signs Hot Topic! “Hot Topics” are our new way of sharing current invasive happenings in the state of Maine. We’ll also include ideas around data collection, classroom resources, and media to help you access more information.

European Green Crab (Carcinus maenas)
First up on our list of critters to keep tabs on is the European Green Crab. European green crabs have been invading our Maine shores for quite some time now but just in the past couple of decades have we noticed a huge impact on our once vibrant soft-shelled clam (Mya arenaria) and blue mussel (Mytilus edulis) fisheries. These shellfish are a favorite meal of the invasive Green Crab. Brian Beal from the Downeast Institute has been conducting research on how Green Crabs predate on Soft-Shell clams. Check out this blog post to learn more: Studying Green Crabs.

Photo by 64rs58s

You can also learn more about green crabs through this great O’Chang animation titled “Attack of the Green Crabs”. This video would be a great resource to share with students. To scaffold watching this video we’ve created this 2-column note tool. Students can complete the notes while watching the video. As a class you can discuss the video use the notes, and review what researchers know about green crabs versus what some of the current hypotheses are. Your students can model what it is like to be an invasive species by playing a modeling game like, “New Bird in Town”. Change out bird species for native and invasives in the intertidal.

We don’t have a long term data set on this species and are in need of more information to draw conclusions about what’s happening in our intertidal. We need your help to build this critical dataset! You and your students can add to what we know about green crabs by contributing to the Vital Signs Field Mission.

As the dataset on Green Crabs research improves and we know more about their possible effects on our ecosystem, we can all learn more about how to better manage this population. Here are some interesting news articles on the subject, keep your eyes peeled for more in the future.