Invasive amphipods as a factor of transformation of Lake Ladoga ecosystems.
The role of invasive amphipods (Baikalian species Gmelinoides fasciatus (Stebbing, 1899) and Ponto-Caspian Pontogammarus robustoides G.O. Sars, 1894 and Chelicorophium curvispinum (G.O. Sars, 1895)) in transformation of the Lake Ladoga ecosystem is assessed. It is shown that presently G. fasciatus plays the main role. Invasion of G. fasciatus into Lake Ladoga has led to an increase in productivity of the littoral benthic communities and more efficient utilization of the energy coming into the littoral zone. It is confirmed that P. robustoides and C. curvispinum are established in the lake. The zone of their dwelling may extend, and the role in the littoral habitats may increase. The analysis of the ecological state of the lake with new indices of the concept for assessing the risks of aquatic species invasions reveals a high degree of transformation of the Lake Ladoga ecosystem.