Littorina littorea

History of Spread

Littorina littorea (Common Periwinkle) is native on the Europe from the White Sea to Gibraltar, but absent from Mediterranean (Bequaert 1943). Specimens of L. littorea (dating back to ~1000-1300 B.C. have been found in Nova Scotia and Newfoundland in Indian and Norse archaeological sites (Clarke 1961; Clarke and Erskine 1963; Spjeldnaes and Henningsmoen 1963). A single fossil specimen from ~40,000 B.C. is also known from Nova Scotia (Vermeij 1982b). This has been taken to infer the presence of native populations of L. littorea in eastern Canada (Clarke and Erskine 1963), or the introduction of this species by Viking explorers (Spjeldnaes and Henningsmoen 1963). It has been argued that oceanographic conditions prevented the spread of these northern populations until their rediscovery around 1840. It is probably more likely that the nineteenth-century spread of L. littorea resulted from later introductions by European settlers (Carlton 1982; Ganong 1887).

One recent molecular analysis (nuclear and mitochondrial DNA) suggested that populations of Littorina littorea on the Atlantic coast of North America are native (Wares et al. 2002). Chapman et al (2007) presented arguments supporting the introduced status of L. littorea, including the likelihood that Ware's analysis insufficiently sampled European genetic diversity, thereby missing possible source populations. A more comprehensive analysis by Blakeslee et al. (2008), incorporating molecular analysis with a greater number samples, parasitological studies, and more sophisticated statistical analysis strongly supports an introduced status for L. littorea in North America, and for its common trematode parasite, Cryptocotyle lingua (Blakeslee et al. (2008), Genetic diversity of L. littorea suggests multiple introductions, possibly as early as Viking times, based on estimates using genetic divergence and assumed mutation rates (400 to 1,000 years ago), but with wide confidence intervals.

The spread of L. littorea along the east coast of the United States is summarized below:

Gulf of St. Lawrence - L. littorea was collected in 1840 at Pictou Nova Scotia, (Ganong 1887); in 1857 in the Bay of Chaleur 1857 (Bathurst, Nova Scotia) (Bequaert 1943); and now occurs north to Labrador (Vermeij 1982b).

Gulf of Maine - In 1857, it was collected in Halifax, on the Atlantic Coast of Nova Scotia (Ganong 1887). It was first collected in the Gulf proper in the Bay of Fundy 1861 (Ganong 1887), occured at Saco ME in 1873, 'in abundance' and reached Provincetown MA by 1870, at which time it was 'very rare'. By 1875, it was abundant (Bequaert 1943; Dexter; 1961)

Vineyard Sound; Buzzards Bay - In 1875 L. littorea was rare at Woods Hole MA, but abundant by 1876 (Ganong 1887).

Rhode Island Sound - In 1880 L. littorea was collected at Newport RI), where it was abundant by 1887 (Ganong 1887; Morse 1881; Verrill 1880b).

Long Island Sound - In 1879, L. littorea was found at New Haven CT (Bequaert 1943). At Cold Spring Harbor (Long Island) in 1899; it was common, but less abundant than other Littorina spp. (Balch 1899).

New York Harbour - In 1888 L. littorea was collected at Staten Island NY. (Bequaert 1943).

New Jersey Coastal Bays- L. littorea was collected at Atlantic City NJ in 1892 (Bequaert 1943).

Delaware Bay - L. littorea reached Cape May NJ by1928 (Bequaert 1943) and Cape Henlopen DE by 1970 (Kraueter 1974).

Atlantic Coastal Bays (Chesapeake Bay region)- In 1959 (Wells 1965) first collectedL. littorean the region. It was rare, 'attached to the rocks of a jetty at West Ocean City' directly opposite Ocean City Inlet' (Wells 1965). At Assateague Island MD-VA in 1988-1989 (exact site not given), it was found 'only on rock jetties and wooden groins' (Counts and Bashore 1991). It was reported from Chincoteague VA in 1971 (Kraueter 1974 ), and later at Wachapreague VA (date not given) (Vermeij 1982b).

Pacific Coast - Scattered occurrences of Littorina littorea have been noticed from Califonria to Washington since 1937. Early occurrences in Puget Sound, Washington (1937, Hannah 1966), and Trinidad Bay, California (Carlton 1969) may have resulted from transplant so Eastern Oysters (Crassostrea virginica). L. littorea was found in San Francisco Bay in1968-70 and 1977, but did not become established (Carlton 1992). Another specimen was found in 1995 (Cohen and Carlton 1995), and occasional occurrences have been noted since (Ruiz et al., unpublished data). In southern California, a single shell was collected in Newport Bay in 1975 Carlton 1979). A small patch of abundant snails was found in Anaheim Bay in 2002 and was eradicated, apparently successfully (Andrew Chang, personal communication).

History References - Balch 1899; Bequaert 1943; Carlton 1992; Clarke 1961; Clarke and Erskine 1963; Cohen and Carlton 1995; Counts and Bashore 1991; Ganong 1887; Kraueter 1974; Morse 1881; Spjeldnaes and Henningsmoen 1963; Vermeij 1982b; Verrill 1880b; Wells 1965

Invasion Comments