European Green Crab
Carcinus maenas
General Characteristics
Appearance:
The European green crab typically has a shell/carapace that is bumpy and shaped like a fan. The shell is about 8-10 cm (3 to 4 inches) wide, with a color range from green to reddish-brown, yellow, or marbled often with yellow or brown blotches. The shell has five curved spines on either side of its eyes and three rounded bumps in between them.
Lifespan:
They can live for about 4 to 7 years.
Reproduction:
Females can produce up to 185,000 eggs at a time, and they typically mate in late summer. The larvae are free-swimming and can drift for several weeks before settling on the ocean floor.
Invasive Nature
Introduction to North America:
The European Green Crab was introduced to North America in the early 1800s, most likely through ship ballast water. Since then, it has successfully established populations along both the East and West Coasts of Canada.
Ecological Impact:
As an invasive species, the European Green Crab poses a serious threat to native ecosystems. It feeds on local shellfish, damages eelgrass habitats, and competes with native crab species. These impacts contribute to reduced biodiversity and can cause significant harm to commercial and recreational fisheries.
Management and Control
Challenges:
Once established, European Green Crab populations are extremely difficult to eliminate. Their ability to survive out of water for more than five days, combined with a prolonged larval stage, allows them to spread easily to new areas.
Reporting and Prevention:
Preventing further spread requires vigilance from boaters and fishers, including thoroughly cleaning gear to avoid transporting crabs or larvae. Reporting sightings is also essential for tracking and managing this invasive species. Due to its resilience and aggressive behavior, the European Green Crab continues to disrupt marine ecosystems across its invaded range, making ongoing monitoring and management critical.
“The invasive European Green Crab are present in the North Coast and we would like to start asking the community harvesters to keep their eyes out when they are walking beaches.
If anyone finds a green crab, they should kill it and notify Tammy or myself of the location and date. Pictures would be greatly appreciated as well. Please use the information guide to help identify the green crab. Share this information to friends, family, and fellow harvesters.
Thank you,“
–Lia
Contact For More Information:
Kitsumkalum Fish & Wildlife
Lia Chalifour, Strategic Lead, Fish and Wildlife / Stewardship Department
Phone: 250-635-5000
Email: lia.chalifour@kitsumkalum.com
Tammy Roberts,
Phone: 250-635-5000
Email: TRoberts@kitsumkalum.com