Green Crabs in the Great Marsh

The following quotes are from our July 20th Zoom screening and Q&A with filmmaker Nubar Alexanian, Ipswich Shellfish Constable Scott LaPreste, and Greencrab.org Director Mary Parks. We recommend viewing Walker Creek Media’s award-winning film, Recipe for Disaster prior to reading.

Please note, the following quotes were edited for clarity and cohesion 

Mary to Nubar: Nubar, could you share some of your experiences filming Recipe for Disaster?

Nubar: I'm an avid fisherman and I've been fishing in the Great Marsh for decades. I had no idea that there were invasive green crabs in the Great Marsh... and most people have that response. This film is a wake-up call about this local invasive species. 

It took me 18 months to make this film. Occasionally you get lucky when making a film. When the trap went over the port side we didn't know what that camera would see. 

See a green crab trap fill up with green crabs in moments  in Nubar’s Documentary, Recipe for Disaster

Mary to Scott: Could you talk a little bit about the status of green crabs on the Great Marsh today?

Scott: I can’t speak for other towns but I can speak for Ipswich which makes up a big chunk of the Great Marsh. However, surrounding towns from the Merrimack river all the way down to Gloucester face similar problems.

We’ve had an active trapping program now for I believe for 7 years. The town and the state have appropriated money so we’re well funded to trap the crabs. We’ve been doing a bounty program that the state has adopted as their model. Over the past few years, the town program has trapped close to 100,000 pounds per season. The season is usually from April to November (when the water warms up and then cools down). There is a market for them outside of our bounty program, typically for tautog bait. However, there are also private markets.

Nubar to Scott: I have a question for you Scott. Even if towns have a budget for trapping green crabs, is this sustainable? 

Scott: I was hoping by now the town would be free and we’d have a market where private individuals are going out and trapping and we don’t need a bounty program. We haven’t gotten there yet. I’d love to see them go towards culinary use but getting them out of the water is key. We know how many eggs the females carry (sources indicate 185,000 per year). 

Mary: I’m going to push back a little on them being difficult to work with. Last night we delivered green crabs to 60 plus people and had so many people reaching out to us with processing techniques we’d never even heard of. What we’ve heard from so many people is that they’re not necessarily difficult to work with but different to work with. People who are used to working with smaller crabs have taught us a lot. 

Processing such as shucking them for meat may be a bit more difficult. However, there are so many recipes that are easy with delicious results. For example, you can easily pop out the crab legs to get a delicious “lollipop” of meat that can be eaten like any other crab leg. 

It’s also helpful to look towards regions where these crabs are native. Everywhere from northern Europe to northern Africa these crabs are utilized in cuisine. For example, Venetians serve them soft-shell and harvest the roe, and chefs in Denmark often use green crabs to create flavorful stocks. 

Community Question: Why are green crabs particularly bad for soft-shell clams?

Scott: When shellfish are juveniles they swim and after that, they settle out. When green crabs spawn they settle right on top of juvenile shellfish and we’re talking about microscopic stuff. When they settle they start to feed on these shellfish right off the bat. According to Dr. Brian Beal in Maine, green crab larvae fall out of the water days after clams settle. His work indicates that clam larvae settlement is largely influenced by predation by green crabs. 

In Ipswich, we have a lot of clams and we have a lot of crabs. This year we’ve trapped about 100,000 pounds. Clam landings are definitely off from last year. No one here knows if that’s because of trapping pressure or if it’s just an aberration. No one year has been close to the other. However, we are seeing new spat (baby clams) coming in two or three years earlier than we would normally expect. I don’t want to draw conclusions but there is the possibility it’s from trapping green crabs. 

After you take in all the economic factors, our clam industry is probably worth 10 to 15 million dollars a year. It’s a big deal and that’s just for Ipswich. 

Maine has a massive coastline and clams are even bigger up there. Maine calls the shots when it comes to clams and sends a lot of clams down to Boston. However, Maine is losing a lot of clams to green crabs. 

I used to be a clammer up in Maine and I didn’t know green crabs weren’t native. I just thought there were crabs in the water. When I got the job I realized crabs were invasive they were from Europe and that they’ve been here for so many years. They were trapping them in the 30s and 50s and it seemed at the time that it brought back our clam population. I wanted to get a program together and then somebody in Maine on the shellfish board reached out and agreed it was a major problem and that’s where we started. Our movement was triggered by the concern going on in the Gulf of Maine. 

Community Question: How easy is it for folks to trap their own green crabs?

Scott: It’s easy, a crab trap isn’t that different from a  lobster or minnow trap. The best bait is swordfish, tuna, and mackerel (think oily fish). The other thing if you’re trapping them is that it’s better to use the heads and the necks. Crabs pick through fish racks very fast so it’s best to use a fish head or tail. Once the bait is gone, it’s hard to attract other crabs so it’s best to use a meatier bit of the fish. Also, if there’s no bait left they’ll even eat each other. They’re voracious. 

Green crabs don’t like the action of the waves so you’ll need to look for green crabs among tide pools, rocky areas, and seaweed. Green crabs aren’t filter feeders so red tide and pollution aren’t big issues like the are for other shellfish. As long as they don’t come from a fowl area they should be fine. 

Community Q: Are there any tricks for harvesting the meat or crab legs and could you elaborate?

Mary: It’s a little hard to demonstrate without a crab but essentially when you apply pressure to the center of the crab while holding three legs together, you’re able to pop out the crab legs with a “lollipop” of meat on the end. Check out our recipe page to learn how to shuck meat and crab legs in detail. 

Thank you to everyone who joined us for this virtual screening and Q&A event. You can listen to the full conversation below.

Visit our Shuck at Home page to learn more about this initiative and other events.

Pictured: Nubar Alexanian in upper left hand corner next to Mary Parks