The European green crab, an invasive species with no natural predators in North American waters, might soon have to contend with the ultimate enemy: humans.

That is, if the solution a chef is cooking up in New Hampshire catches on.

"We make them primarily into broths because they are so tough and small. You get this really deep sea flavour with the sweetness from the crab and I think it tastes better than lobster stock or certainly better than fish stock or mussel stock," Chef Brendan Vesey said. 

The European green crab is a huge problem in the waters off New Hampshire, where they have been found off its coastline for about 200 years.

Brendan Vesey

Chef Brendan Vesey says the stock he makes from green crabs has better flavour than broths made from lobster, fish or mussels.

"They've impacted especially the soft shell clam fishery heavily," said Vesey, who works at The Joinery restaurant in Newmarket, a town less than 30 kilometres from the Atlantic Ocean. 

The species is also a big problem in Canada, where the green crab has been found in the Maritimes and the Gulf of St. Lawrence, and made its way to Newfoundland waters in 2007, first appearing in Placentia Bay. Voracious eaters of shellfish like clams, and mussels, the crabs also eat juvenile lobsters and compete with adult lobsters for food. The population is proving impossible to control, with females spawning up to 185,000 eggs per year. 

Recipes get rave reviews

Vesey says it's not worth the effort to shuck the crabs for their meat due to their small size — the average crab shell is about 10 centimetres long — but the stock used in various dishes has gotten rave reviews from customers for the tasty flavour. 

"We heat a pan up with a little slick of hot oil in it and we'll add the crabs to it as if we were doing a crab boil, and then add some onion and fennel and garlic and spices. And sometimes a little sherry or white wine, and then we'll add water," explained Vesey. 

I think the enjoyment of eating something invasive is really high for a lot of people. - Brendan Vesey

Green crab has appeared on The Joinery's menu in other ways​.

"We had a starter soup in a small glass that we called 'Crabaccino' that we made for some fishermen who were in one time," said Vesey. 

It's not only Vesey's customers who've been gobbling up green crab: chickens in the Newmarket area have grown fond of the taste too. Vesey grinds up the leftover crab shells and gives the mush to a neighbouring chicken farmer. 

"The chickens love it, all that rich calcium in the shells and the rest goes into a compost pile for his garden and then he gives us eggs in exchange."

Green crab

The European green crab is believed to have arrived in Newfoundland in the ballast water of oil industry vessels. It was first spotted in Placentia Bay in 2007.

Vesey pays harvesters $2 a pound for green crab. He's trying to come up with even more ways to incorporate the invasive species into his cooking. 

"I think the enjoyment of eating something invasive is really high for a lot of people. They want to be helpful and as humans we're probably the best eradicator of species on the planet and if we could just find the right species to eradicate, we'd be a lot more helpful," explained Vesey. 

So far, on the island of Newfoundland, green crab is now known to be present in Placentia Bay, Bay St. George and in Fortune Bay, home to one of this province's most lucrative lobster fisheries.