Establishment of dense Dreissena populations can have large impacts on benthic communities, such as increases in benthic plant and algal abundance (Griffiths 1993, Lowe and Pillsbury 1995, Skubinna et al. 1995, Stuckey and Moore 1995), increases in the density of benthic invertebrates (Stewart et al. 1998), and changes in the overall benthic community structure (Sokolova et al. 1980, Dermott and Munawar 1993, Griffiths 1993, Karatayev et al. 1994, Stewart and Haynes 1994, Wisenden and Bailey 1995, Botts et al. 1996, Howell et al. 1996, Karatayev et al. 1997, Stewart et al. 1998, Strayer et al. 1998, Strayer et al. 1999).
These benthic impacts have also been documented in the former Soviet Union and other European freshwaters (Karatayev et al. 1997). In benthic communities within their native Eurasian distribution, such as the brackish waters of the Caspian Sea, Aral Sea, and Azov Sea, Dreissena generally are not the dominant species (Vorobiev 1949, Shorygin and Karpevich 1948). In freshwaters, where they are the only bivalves that attach to hard substrates and have a planktonic larval stage, they can become enormously abundant, sometimes obtaining a biomass 10 times greater than that of all other native benthic invertebrates (Lyakhnovich et al. 1988, Karatayev and Burlakova 1995b). The presence of individual zebra mussels on the bottom does not change the composition of the benthic community; however, in the presence of druses, the community can change radically (Karatayev et al. 1983). In general, zebra mussels have been associated with changes in taxonomic assemblages, trophic structures, density, and biomass of the benthic community.
Alteration of the Freshwater Ecosystem, An Overview
Functional Relationships Between the Zebra Mussel and Other Benthic Species
Impacts of Pseudofeces in the Benthos
Impacts on the Benthic Trophic Structure