Invasion
Invasion Description
1st Record: Newport/RI/Narragansett Bay (1880, Verrill 1880)
Geographic Extent
Fall River/MA/Mount Hope Bay (1950, USNM 595270, U.S. National Museum of Natural History 2007); Bristol/RI/Mouth of Warren River, Narragansett Bay (MCZ 223541, Museum of Comparaitve Zoology 2008); Rocky Point, Warwick/RI/Narragansett Bay (USNM 407580, U.S. National Museum of Natural History 2007); Colt State Park, Bristol/RI/Narragansett Bay (2000, MIT Sea Grant 2007); Tiverton/RI/Sakonnet River (1932, MCZ 163257, Museum of Comparative Zoology 2008); Wickford/RI/Narragansett Bay (MCZ 223542, Museum of Comparatve Zoology 2008); Narragansett Pier/RI/Rhode Island Sound (MCZ 223543, Museum of Comparaitve Zoology 2008); Newport/RI/Narragansett Bay (1880, Verrill 1880, abundant by 1887, Ganong 1887)
Vectors
| Level | Vector |
|---|---|
| Alternate | Natural Dispersal |
| Alternate | Hull Fouling |
| Alternate | Dry Ballast |
Regional Impacts
| Ecological Impact | Herbivory | |
| Removal experiments in Mount Hope Bay, RI, indicate that herbivory by Littorina littorea removes leafy algae such as Ulva spp. on a cobble beach, resulting in the growth of an algal canopy. Grazing by L. littorea also reduced the growth and reproduction of the marsh grass Spartina alterniflora (Smooth Cordgrass) by consuming rhizomes of the plant (Bertness 1984). | ||
| Ecological Impact | Habitat Change | |
| Removal experiments in Mount Hope Bay, RI, indicate that herbivory by Littorina littorea has major effects on habitat structure, by removing algae and Spartina, preventing the accumulation of sediment, and removing habitat available for soft-bottom fauna (Bertness 1984). Bertness suggests that the Littorina invasion may have resulted in the reduction of marsh habitat and other soft-sediment habitats (Bertness 1984). | ||
| Ecological Impact | Competition | |
| In Mount Hope Bay, RI, I. obsoleta was observed to emigrate from sites where large numbers of L. littorea had been added (Bertness, unpublished, cited by Brenchley and Carlton 1983). | ||