Аннотация:The problem of sedimentation of port harbors in the region is very relevant,but there is no understanding of how and why this occurs. This paper presentsthe results of calculations of longshore sediment flows in the area of the port ofShakhtersk, located on the western coast of Sakhalin in the Tatar Strait. Analysisof repeated bathymetric surveys of the harbour and approach channels has quantitativelyconfirmed the validity of a methodology that has previously been used on theshores of north-east Sakhalin, Terpeniya Bay and Aniva Bay for coastal protectionpurposes.