Invasion
Invasion Description
1st Record: Table Bay Docks, Cape Town in 1983. By 1990, Carcinus spp. ranged from Camps Bay to Cape Saldanha, a 200 km stretch of the South African Coast (Griffiths et al. 1992; Mead et al. 2011b).
Geographic Extent
Cape Town/South Africa/Table Bay docks (1983, Griffiths et al. 1992; Mead et al. 2011b); Bloubergstrand/South Africa/Atlantic Ocean (1984, Griffiths et al. 1992); South Africa/Camps Bay (Griffiths et al. 1992); Cape Town/South Africa/Hout Bay (Robinson et al. 2005); South Africa/Saldanha Bay (1990, establishment unknown, Robinson et al. 2005; Haupt et al. 2010, established, oyster farms). Samples included a mix of C. maenas and C. aestuarii genotypes (Geller et al. 1997). Mabis e al. 2022 reported only a single genetically identified C, aestuarii in South Africa. Mabis et al.'s genetic analysis suggests that the introduction occurred much earlier than recorded in the literature, as early as 1895 ((%%CI 1683-1995). The data also suggest a geneitc admixture from a population from Canada (Mabin et al. 2022).
Vectors
| Level | Vector |
|---|---|
| Probable | Ballast Water |
| Alternate | Hull Fouling |
Regional Impacts
| Ecological Impact | Competition | |
| Competition with native crabs is expected to be limited because of differences in habitat use (Griffiths et al. 1992). | ||
| Ecological Impact | Predation | |
| Carcinus maenas could be an important predator in protected waters (Griffiths et al. 1992). | ||