The Asian isopod Ianiropsis serricaudis is now well established in fouling communities, often associated with introduced ascidians, throughout the Northern Hemisphere but has gone largely unnoticed because of its diminutive size (typically less than 3 mm in length) and the difficulties of identifying small peracarid crustaceans. Known locations include the northeastern Pacific (Puget Sound, San Francisco Bay, and Monterey Bay), the northwestern Atlantic (from the Gulf of Maine to Barnegat Bay, NJ), and the northeastern Atlantic (England and the Netherlands). We predict that this species is widespread along North America and European coasts, and may already be introduced to cold temperate waters of the Southern Hemisphere as well.
Invasive species threaten marine biodiversity on a global scale.
To test whether marine reserves provide resistance to invading species, the abundance of two conspicuous invaders, a seaweed and an oyster, were measured inside marine reserves and in comparable areas outside reserves in north-western Washington State.
Densities of both invaders were significantly higher in marine reserves than in comparable unprotected areas outside reserves. Although the causal mechanisms have not yet been identified, differential rates of human harvest do not appear to be responsible for the patterns observed.
It is provisionally suggested that physical or biological aspects of the reserves themselves may directly or indirectly facilitate biological invasion.