1st Record: Estonia/Pärnu Bay in the Gulf of Riga (1855, Birnbaum 2011; Leppakoski et al. 2002)

Estonia/Pärnu Bay in the Gulf of Riga (1855, Birnbaum 2011; Leppakoski et al. 2002); Lithuania/Gulf of Riga (Strayer and Smith 1993)

Level	Vector
Probable	Canal

Ecological Impact		Habitat Change
Moderate habitat impacts (Zaiko et al. 2011).

Ecological Impact		Trophic Cascade
Moderate ecosystem impacts (Zaiko et al. 2011).

Ecological Impact		Herbivory
Rates of feeding and deposition of feces and pseudofeces in the brackish Gulf of Riga were about 1/10 of those of Zebra Mussels in freshwater lakes, so impacts are expected to be smaller (Lauringson et al. 2007). Feeding rates are affected by salinity, windspeed, and chlorophyll concentrations (Oganjan and Lauringson 2014).

Species Regional Summary Dreissena polymorpha None ( B-VIII )