Green Crab Surveys

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Fast Facts: What are Green Crab Surveys?A volunteer holds a green crab up for the camera.

Volunteers are needed to search the coast for green crabs (Carcinas maenas) to contribute to a study evaluating the potential for a commercial fishery to help control this nonnative species. Green crabs are edible, but because they are smaller than other popular crabs, they are not commonly harvested for food. To this end, NH Sea Grant is researching when green crabs molt to explore the feasibility of a soft-shell crab market (similar to blue crabs). Green crab surveys are conducted as part of NH Sea Grant's NH Green Crab Project


Volunteer Description: What do Green Crab Survey volunteers do?

Volunteer Experience: Volunteers will receive a brief training in crab identification and survey methods with Sea Grant biologist Dr. Gabby Bradt. Small groups of volunteers will then choose a location on the coast to conduct a crab survey, and volunteers will depart for their survey locations. Once you're trained, you can survey for green crabs anytime you're near the coast--the more data, the better!

Time Frame: Expect to spend about two hours in the training and on your survey. Once trained, you can conduct brief surveys near the coast anytime you'd like.

Project Impacts: The green crab is an invasive species that has wreaked ecological and economic havoc along the New England coast for decades. As ocean temperatures have increased, the populations of these crabs continue to explode. Currently, there is no strategy in place to control the populations of green crabs, and there is no real commercial market or fishery for these invaders. The goal of the NH Green Crab Project is to identify a clear window of time when male and female green crabs are molting as part of the exploration of the  soft-shell green crab market and fishery in the Granite State.


  • Interest in helping better understand and manage nonnative this coastal species
  • Desire to spend time along New Hampshire's rocky coastline!


  • Opportunities to learn about green crabs and other rocky coastal species
  • Contribute to a study on management of the invasive green crab
  • Meet people from your community with similar interests

Questions? For more information, contact Alyson.


Upcoming Opportunities: Join a Green Crab Survey!

Our monthly Great Green Crab Hunts have come to an end for 2018. To learn about new green crab survey opportunities as they go on the calendar, sign up for our newsletter!

There may also be opportunities for more in-depth volunteer experiences, including trapping green crabs and helping to process green crabs at Jackson Estuarine Laboratory. If you're interested in these additional volunteer opportunities, contact Sea Grant's Dr. Gabby Bradt at or 603.862.2033.


Learn More: Links, resources, and partner organizations

Want to learn more? Visit the NH Green Crab Project website, check out this green crab field guide, or learn a little more about green crabs in the Gulf of Maine.


Volunteer Resources

Online data submission form - submit your green crab sightings here!
Paper version of data sheet - don't want to use the app? Use this in the field, then come home and enter your sightings online
Green crab identification guide


Gabby Bradt holds up a green crab at a rocky shoreline site in NH.


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