Species Regional Summary
Dreissena polymorpha
_CDA_L123 (St. Lawrence River) ( L123 )

Vectors

Level	Vector
Alternate	Ballast Water
Alternate	Natural Dispersal
Alternate	Hull Fouling

Regional Impacts

Ecological Impact		Predation
In Robinson Bay, off the St. Lawrence River, near Massena NY, in mesh enclosures containing Dreissena polymorpha, the abundance of the rotifer Polyarthra sp. declined drastically, indicating predation on this and other microzooplankton. Enclosures with the native mussel Elliptio complanata showed no change in rotifer abundance. Chlorophyll levels in the treatments did not differ, indicating that the effect was due to predation (Thorp and Casper 2002).
Ecological Impact		Trophic Cascade
In Robinson Bay, of the St. Lawrence River, near Massena NY, in mesh enclosures containing Dreissena polymorpha, abundances of the copepods Eurytemora carolleeae (reported as E. affinis) increased dramatically, presumably due to reduction of competition from rotifers (Thorp and Casper 2002).
Ecological Impact		Habitat Change
In Lake Champlain VT-NY, Zebra Mussels have extensively colonized soft sediment. Colonized sediment supported communities with a greater abundance and diversity of benthic invertebrates than adjacent sediments, lacking mussels. Experiments in which mussels were added to uncolonized sediment, or removed from colonized sediment also showed that mussels promoted increased abundance and diversity of macrobenthos (Beekey et al. 2004a). Zebra Mussels also adversely affected the foraging success of 3 benthic fishes and a crayfish, by providing shelter to prey organisms. However, the shelter effect may be offset by the increase in the density of prey (Beekey et al. 2004b). In the St. Lawrence River, near Montreal, both the introduced amphipod Echinogammarus ischnus and the native Gammarus fasciatus used Zebra Mussel colonies as shelter, about equally (Palmer and Ricciardi 2005).
Ecological Impact		Competition
Fouling by Zebra Mussels is reported to have caused a >90% decline in native unionid mussels in the St. Lawrence River near Montreal (Ricciardi et al. 1998).

References

Adebayo, Abisola A.; Zhan, Aibin; Bailey, Sarah A.; MacIsaac, Hugh J. (2013) Domestic ships as a potential pathway of nonindigenous species from the Saint Lawrence River to the Great Lakes, Biological Invasions Published online: <missing location>

Beekey, M. A.; McCabe, D. J.; Marsden, J. E. (2004a) Zebra mussel colonisation of soft sediments facilitates invertebrate communities., Freshwater Biology 49: 535-545

Beekey, McCabe, D. J.; Marsden, J. E. (2004b) Zebra mussels affect benthic predator foraging success and habitat choice on soft sediments., Oecologia 141: 164-170

Marsden, J. Ellen; Hauser, Michael (2009) Exotic species in Lake Champlain, Journal of Great Lakes Research 35: 250-265

Palmer, M.E.; Ricciardi, Anthony (2005) Community interactions affecting the relative abundances of native and invasive amphipods in the St. Lawrence River., Canadian Journal of Fisheries and Aquatic Sciences 62: 1111-1118

Ricciardi, Anthony, Neves, Richard J., Rasmussen, Joseph B. (1998) Impending extinctions of North Americam freshwater mussels (Unionoida) following the zebra mussel (Dreissena polymorpha) invasion, Journal of Animal Ecology 67: 613-619

Ricciardi, Anthony; Whoriskey, Fred G. (2004) Exotic species replacement: shifting dominance of dreissenid mussels in the Soulanges Canal, upper St. Lawrence River, Canada, Journal of the North American Benthological Society 23(3): 507-514

Thorp, James H.; Casper, Andrew F. (2002) Potential effects on zooplankton from species shift in planktivorous mussels: a field experiment in the St Lawrence River., Freshwater Biology 47: 107-119

2003-2022 Nonindigenous Aquatic Species Database. Gainesville, FL. http://nas.er.usgs.gov

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