Northern skerries shore is under the threat of pollution with municipal sewage from Priozersk, Sortavala and Pitkaranta discharged into the lake with practically no prior treatment. Given the poor water exchange in the water areas between numerous islands the discharges are a serious ecological threat. This refers also to the accumulation zones of effluents from the pulp-and-paper mill near Priozersk and the village of Laskela.
Western shore (from Priozersk to the Morjin nos promontory)
shows the signs of the heaviest man-made pollution in the Burnaya river estuary
and Vladimirskaya bay. These areas were noted to have inter alia increased
137Cs concentrations in bottom sediments.
Southern (bay) shore hosts some phenomena of technical genesis. The main ones are water-engineering facilities (Novo- and Staroladozhsky canals), and underwater waste dumps in the coastal zone. Considerable microbial pollution was recorded in the estuary areas of the rivers Volkhov, Svir and Syass - the largest rivers in the Lake Ladoga basin. The near-shore water of the Petrokrepost bay is contaminated with heavy metals. Storm runoff from the Syass pulp-and-paper mill settling pond is a continuous threat to the Ladoga aquatic ecosystems.
Eastern shore (from the Svir bay to Pitkaranta) is ecologically the most resistant. Bottom sediments are the "cleanest" here. The near-shore zone has the highest benthos biomass. Some samples from the Olonka and Vidlitsa river estuaries however were found to contain increased concentrations of organochlorines.