Microbial indication of pollution for the surface waters in the Novik Bay (Russky Island, Peter the Great Bay, Japan Sea)
The Novik Bay is the largest one among the inlets of Russky Island in Peter the Great Bay. This water area is actively used for aquaculture and commercial and recreational fishery and attracts many tourists, so permanent monitoring of its water quality is necessary. Current environmental situation in the Novik Bay is assessed using microbiological indicators. The following parameters are used: total number of heterotropic bacteria, number of coliform bacteria, and number of metal-resistant microorganisms as indicators of oil and phenolic pollution. The water samples were collected in spring and autumn of 2017 and in spring and summer of 2018, following the standards GOST 31862 and GOST 31861. The number of microorganisms was determined by standard microbiological methods of sowing. The total number of heterotrophic bacteria corresponds to the requirements for oligo- or mesosaprobic waters. The number of metal-resistant microorganisms indicates that the waters of the bay are not subjected to industrial effluents and other man-made effects, its pollution by oil products is noticeable in some local areas only but the major part of the bay is low-polluted. In comparison with the data of previous chemical-ecological and microbiological tests, these assessments show better condition of the Novik Bay waters.