European shore crab
Portunidae - Carcinus maenas

What does it look like?

Adult specimen shells can reach widths of up to 8 cm, with five spines or spikes on each side of shell. Their colour varies from green top shell and yellowish underside, to red/orange mottled top shell and orange or partly red underneath with juveniles generally lighter in colour than adults. There are also three rounded teeth or lobes between their eyes and no swimming paddles on its legs.

European shore crabs can be found in all types of protected and semi-sheltered marine and estuarine habitats, including mud, sand, rocky substrates and seagrass beds from the inter tidal to 60 m deep, although it is predominantly a shore to shallow water species.

Why is it a problem?

The European shore crab is a highly adaptable, and therefore invasive species. It is a voracious predator, eating mussels, crabs, oysters, limpets, barnacles, worms, juvenile crabs and shellfish including scallops. This species has the potential to significantly alter ecosystems causing mortality in native crab and shellfish populations.  European shore crabs have been implicated in the decline of native shellfish populations overseas, with some species of commercial importance.

Control Methods

You can help prevent the spread of marine pests by:

• Regularly cleaning your boat’s hull – ideally keep fouling growth to no more than a light slime layer.

• Applying a thorough coating of antifouling paint and keep it in good condition

• Ensure your hull is clean and free of fouling before you go travel to a new area

• Clean and dry any marine equipment (e.g. ropes, lines, pots) before using in a new area.

• Inspect areas on your boat that retain water for signs of marine life.

• Check for aquatic weeds tangled around anchors, trailers and other equipment.


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