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European Green Crab

European Green Crab

European Green Crab

Carcinus maenas

Learn about European Green Crab, including its identifying features, location, habitats, impacts and our response.

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Identifying features

The European Green Crab (Carcinus maenas) is a small coastal crustacean. You can identify it by its:

If you think you have seen a European Green Crab, report it.

Nearshore native crabs found in eastern Canada that look similar to the European Green Crab include:

Nearshore native crabs found in western Canada that are green in colour and can be mistaken for European Green Crab include:

Where is the species invasive

In Canada, European Green Crab has invaded:

Although they look the same, there are different populations of European Green Crab found in eastern Canada. The first population spread into Atlantic Canada in the early 1950s, moving north from the eastern North Atlantic seaboard and are not cold tolerant.

A second population arrived in the 1980s and 1990s in northern Nova Scotia and are better suited to survive colder waters as they originated from populations in northern Europe. These two populations have mixed and reproduced forming a third cold tolerant hybrid population that is also rapidly spreading both north and south in Atlantic Canada.

Established populations of European Green Crabs have been found on the west coast of Vancouver Island. Since 2018, new detections of European Green Crab have been found on: northern Vancouver Island (Port Hardy); southern Vancouver Island (Esquimalt Lagoon, Witty’s Lagoon); the Gulf Islands (Salt Spring Island); Haida Gwaii and, in southern British Columbian waters (Boundary Bay).

Distribution

The European Green Crab is native to Europe and North Africa. It likely arrived in North America around 1817 carried in the holds of wooden ships.

European Green Crabs are thought to spread during their long larval stage (up to 90 days) through shipping (ballast water transfers) or by drifting on ocean currents. They can also move from one area to another by hitchhiking unseen on boats and gear or in packaged shellfish.

Habitat

The European Green Crab are found near shore, usually in shallow waters less than 6 metres. They can tolerate a wide range of water temperatures and salinities (salt content of water). They are found in:

The adult European Green Crab is very hardy and can survive out of water for five or more days. Its hiding places include:

Impacts

The European Green Crab is highly resilient and can upset the balance of estuarine and marine ecosystems, impacting biodiversity. European Green Crab:

Ecological impacts

European Green Crab impact native ecosystems by:

Socio-economic impacts

European Green Crab impact the fishing and aquaculture industries by:

Response

Once European Green Crab have established a population in an area, it is practically impossible to eradicate them. However, we can limit their spread and the damage they cause.

Fisheries and Oceans Canada is collaborating with many partners including:

We provide training on proper identification, sampling methods and data collection standards. Appropriate licencing to detect early invasions and to control populations of European Green Crabs are available in some areas. If your organization is interested in partnering, please contact us.

Where sustained removal of European Green Crab has taken place, the catch rate for these crabs has decreased considerably and native species have regained their territory.

European Green Crab’s 5 spines

European Green Crab’s 5 spines

European Green Crab

European Green Crab

Fukui trap full of European Green Crab

Fukui trap full of European Green Crab

European Green Crab

European Green Crab

European Green Crab

European Green Crab

European Green Crab (Top) and native Rock Crab (bottom)

European Green Crab (Top) and native Rock Crab (bottom). © A. Vickerson, Marine Institute of Memorial University

European Green Crab

European Green Crab. © AVC - UPEI J. Davidson

Lady Crab

Lady Crab

Female European Green Crab

Female European Green Crab

Jonah Crab

Jonah Crab

Rock Crab

Rock Crab

Hairy Shore Crab

Hairy Shore Crab

Northern Kelp Crab

Northern Kelp Crab

Helmet Crab

Helmet Crab

Maps

Green Crab Distribution in Newfoundland Waters.
Description

European Green Crab have been found on the south coast of Newfoundland and Labrador, throughout Placentia Bay, in Fortune Bay and St. Mary’s Bay. They have also been found on the west coast, from Bay St. George up through the Humber Arm area and Penguin Arm, and from Rocky Harbour to Port Saunders.

Green Crab Distribution in Gulf region.
Description

European Green Crab is widely distributed in the Gulf region. In particular Prince Edward Island and the southern coastlines of New Brunswick and the northern parts of Nova Scotia are widely invaded by Green Crab. Currently, Green Crab has not yet been detected in northern shores of the Acadian Peninsula. On Cape Breton, Green Crab has only been found in the very southern parts of the Cape Breton Highlands National Park of Canada.

Green Crab Distribution in Maritimes region.
Description

The first detections of European Green Crab occurred in the Maritimes region, and as such, European Green Crab is widely distributed in the Maritimes region. In the mid-1960s to the mid-1970s, European Green Crab distributions were limited to areas south of Halifax, but it is likely that the invasion of the second 'type' of European Green Crab allowed them to spread north of Halifax.

Green Crab Distribution in Pacific region.
Description

Detection map of confirmed sightings of European Green Crab in the Pacific Region. For the most up-to-date map of detections, visit the detection map for Pacific Region.

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