European Green Crab

European Green Crab

(Carcinus maenas)

French common name: Crabe vert

Description:  

The European Green Crab is an aggressive non-native crab species that competes with native crab species for food and resources, and was first identified in New Brunswick’s waters in 1951. This invasive species has since expanded to many other places in Atlantic Canada, with 2 distinct populations being recorded throughout the Bay of Fundy and Gulf of St.Lawrence.

Problem:  

European Green Crab are an aggressive species, and negatively impact marine and estuarine ecosystems by outcompeting native crabs for food and resources, disrupting complex food webs and decreasing native crab diversity. This invasive species also impacts fish and aquatic environments by disrupting sensitive environments like eelgrass beds, which is important habitat for a variety of fish and mussel species (see paper in file) 

Species identification:

Adult crabs can grow up to 10 cm in size, with young crabs closer to 3-4 cm. They can be found along many New Brunswick coastlines and have a trapeze-shaped serrated shell with 3 spines between the eyes and 5 spines on either side of the eyes. European Green Crabs can vary in colour including green, yellow, and red, and have 2 claws of different sizes.

How it’s spread:  

It is thought European Green Crab was introduced through infested ship ballast soil and water that was brought to coastal cities and released into the local environment. This invasive species is further spread throughout the province through boating and recreation through aquatic equipment, so it’s important to Clean, Drain, and Dry all equipment before moving between waterbodies to prevent this invasive species.