Abstract <p>A comprehensive procedure for assessing the environmental conditions of bottom sediments in a seaport water area with a high degree of anthropogenic pollution is proposed for measures to mitigate cumulative pollution impacts. The procedure combines remote sensing, instrumental, and chemical-analytical research methods. The complex approach makes it possible to promptly assess the cumulative environmental impacts. Remote sensing provides reliable data on sunken objects, the structure and volume of sediments. Hydromagnetic survey makes it possible to estimate the location and dimensions of ferromagnetic sources. The structure of the upper layer of sediments can be estimated by continuous seismoacoustic profiling. Multibeam echo sounder is used for sounding survey and sonar survey of the bottom, detecting large submerged objects. Matching of bathymetric and seismoacoustic digital models of the seabed helps to assess the thickness of the upper layer of sediments in different parts of the water area. Based on the sampling and analysis, physical-chemical characteristics and the content of priority pollutants in water and sediments can be determined. To assess the state of the ecosystem, ecological indices of bottom sediments pollution (<i>C</i>_<i>f</i>, <i>mC</i>_<i>d</i>, <i>I</i>_geo, TEL/PEL, SQG-Q) are calculated. Based on the proposed complex procedure, a survey of the Zolotoy Rog Bay (Vladivostok, Russia) was carried out. The study showed a high degree of the water and sediments pollution. Different sites of the bay floor were ranked according to the volume and hazard of cumulative environmental impacts. The results of this work provided the basis for developing comprehensive measures to mitigate cumulative environmental impacts of bottom sediments in the bay.</p>