This article covers the topic of comparative biostratigraphy of anthropogenic deposits associated with the Yankovski culture dated to the Iron Age. These deposits are known as "shell middens". During the last 20 years the authors were applying a unique technique while investigating the shell middens. Their efforts yielded a database of entirely new quality, with the focus on alterations in the ancient population's habits of malacofauna procurement, as the latter reflected environmental changeability. As a result, the authors offer a reconstruction of climatic and ecological dynamics in coastal zone of Peter the Great Bay.