Invasion
Invasion Description
1st Record: Probably present by 1875-1880, based on surrounding records.
Geographic Extent
ME/Frenchman's Bay (USNM 186072, US National Museum of Natural History 2007); Bar Harbor/ME/Frenchman's Bay (USNM 435389, US National Museum of Natural History 2007); Grindstone Neck/ME/Gulf of Maine (Lubchenco and Menge 1978; Lubchenco 1980; Lubchenco 1983; Lubchenco 1986)
Vectors
| Level | Vector |
|---|---|
| Alternate | Natural Dispersal |
| Alternate | Dry Ballast |
| Alternate | Hull Fouling |
Regional Impacts
| Ecological Impact | Herbivory | |
| Littorina littorea is the most abundant herbivorous intertidal invertebrate on rocky shores in the Gulf of Maine. Manipulative experiments indicated that L. littorea did not graze significantly on the dominant alga, Chondrus crispus, when it was already established, but did affect algal succession by grazing on emphemeral algae (e.g. Ulva spp. which compete with Chondrus, damping variation in Chondrus abundance; Lubchenco 1978; Lubchenco and Menge 1978). The periwinkles graze the germlings of the larger brown seaweed Fucus spp., but also benefit Fucus by removing competitive ephemerals and epibiotic algae (Lubchenko 1980; Lubchenco 1983; Lubchenco 1986). Impacts of L. littorea were greatest at sheltered sites, since L. littorea was rare or absent at sites with heavy wave action (Lubchenco 1978). Moderate abundances and impacts of L. littorea were found at Grindstone Neck (near Schoodic Point), Maine (Lubchenco and Menge 1978; Lubchenco 1980; Lubchenco 1983). | ||
| Ecological Impact | Habitat Change | |
| Grazing by Littorina littorea helps to benefit canopy-forming seaweeds such as Chondrus crispus spp. and Fucus spp. by removing ephemeral alga competitors. The canopy forming seaweeds provide shelter for many species of intertidal invertebrates (Lubchenco and Menge 1978; Lubchenco 1980; Lubchenco 1983). Moderate abundances and impacts of L. littorea were found at Grindstone Neck (near Schoodic Point), Maine (Lubchenco and Menge 1978; Lubchenco 1980; Lubchenco 1983). | ||