Ecological communities suffer dramatic changes when non-native species are introduced by humans!

Ecological communities suffer dramatic changes when non-native species are introduced by humans. Such introductions have been documented in hundreds of locations and appear to be common in marine and island habitats. One of the best-studied cases of a species that suddenly appeared in the New England intertidal, and subsequently spread rapidly southward accompanied by significant changes in the intertidal community, is the “European periwinkle” Littorina littorea.

In the July issue of Ecology Letters, a team lead by a scientist from the University of New Mexico used detailed genetic analysis to show that this snail could not have been introduced by European colonists, as is often suggested. Instead, populations of L. littorea appear to have survived in the Canadian Maritimes for well over 10,000 years. The sudden increase in population size and geographic range of L. littorea is still likely to have been induced by anthropogenic change, but only further investigation of the history of ecological interactions among New England intertidal species will illuminate these indirect effects and their general importance in habitat conservation.