Natural middle-and late-Holocene environmental development of Kunashiri Island reflects global climatic changes and the migration of warm and cold currents. Dry and cool climate changed to warm and moist about 7000–6500 BP, later than on Hokkaido Island. At this time Kuroshio Current system became more active. On Kunashir Island birch assemblages were replaced by cool-temperate broadleaf forests in the south and mixed coniferous/broadleaf forests in the north. The highest sea-level position reached 2.5–3 m above PSL about 6500–6300 BP. Cooling about 4700–4500 BP island vegetation weakly changed that connected with warm current influence. Major regression at this period led to formation of extensive coastal dunefields. The warming at the beginning of the late Holocene was almost similar to the Holocene Optimum. Two minor transgressions are recorded about 4010–3400 and 2950–2620 BP. Active entrance of detrital material to the coastal zone resulted in growth of accumulative landforms. Vegetation changes and climatic deterioration took place in the second half of the late Holocene. Coniferous and mixed coniferous/broadleaf forests shifted southward and occupied a large part of the island. During cooling at 1700–1300 BP the isthmus area increased, coastal wetlands with lakes and coastal dunes were formed, and grassland and swamp landscapes developed. Late-Holocene warming was not intensive. Active aeolian accumulation took place during the ‘Little Ice Age’ cooling and regression.

The study of Holocene deposits on Iturup Island is very important for understanding palaeolandscape changes on the island. It is separated by deep straits from the neighbouring islands and was isolated during the last glacial maximum. Landscape changes over the last 40000 years and the role of refugia on vegetation development are discussed. Changes in natural processes in this region were controlled both by global climatic changes and by regional factors. Birch forests developed at the warming about 36-37 ka ago, whereas tundrapark landscape developed with the cooling of the last glacial maximum. Holocene environments reflect climatic changes and sea-level oscillations. The fluctuation of warm and cold currents influenced the landscape development. At the Holocene Optimum (about 6 ka) broadleaved forests with Quercus, Phellodendron, Carpinus, Juglans, Fagus, Fraxinus and Syinga occupied the Okhotsk side of central Iturup. Climate was warmer than present and the sum of active tempe]ratures (σ ≥10°C) was not less than 1800°C. The warming was coincident with the transgression with the highest sea level up to 3.5 m above present sea level (PSL). Numerous coastal lakes were formed at this time. A shallow strait occurred on the low Vetrovoy isthmus. The sea-level drop at 4700-4500 radiocarbon years BP led to the development of large dunefields only within bays with a flat coast due to the supply of sandy material from the inshore drainage zone. At the beginning of the late Holocene about 4000 BP the vegetation changed very little due to the warm current influence. Cool-temperate forests with dominant Quercus had a wide distribution, but the diversity of broadleaved genera decreased. A minor transgression occurred about 4100-4000 BP with a sea-level rise on about 2.5 m above PSL. Active accumulation of deposits took place in the coastal zone at this time. Great vegetation changes and climatic deterioration took place in the last 2000 years BP. Cool-temperate broadleaved forests were confined to the Okhotsk side of the central island. Grasslands and swamps also developed in the coastal lowlands at this time. A minor regression led to the formation of large dunefields. Isthmuses increased and coastal wetlands with lakes formed. The presence of marine diatoms in floodplain lake deposits indicates a sea-level rise at about 1060 ± 60 BP. At this time warming was not intensive, but was well pronounced. The last phase of active aeolian accumulation took place during the ‘Little Ice Age’ cooling and regression.

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The bivalve molluscan fauna of Vrangel Bay, a small embayment in the eastern part of Peter the Great Bay (Nakhodka Bay), and in several localities along the coast of middle Primorye (Maritime Province, both in north-western part of the Sea of Japan, was studied based on 185 dredge and SCUBA-diving samples (in all, 40 stations). A total of 58 species of bivalves were identified. Eight species are recorded for the first time from the coast of middle Primorye. Comparative analysis ofbathymetric ranges of bivalve mollusks from different parts of the Sea of Japan is carried out, and presence of shells believed to be subfos~il and redeposition of Recent shell remains are discussed. Cold-water and relatively cold-water mollusks occur in Vrangel Bay, a protected bay, in shallow waters which can be explained by the influence of the cold Primorskoe Current. The faunal differences between eastern and western parts of Peter the Great Bay are emphasized. Taxonomic and biogeographic comments on some species are given.

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The bivalve molluscan fauna of Ulsan Bay, East Sea coast of Korea, is summarized, based on original and literature data. The fauna consists of 61 species belonging to 20 families. Seven species are identified only to genus level. Two species (Carditellopsis toneana , Carditidae and Fulvia hungerfordi (G.B. Sowerby III, 1901), Cardiidae) are new records for the East Sea coast of Korea, and one species (Crenella decussata (Montagu, 1808), Mytilidae) is a new record for Korea. Biogeographically, Ulsan Bay's bivalve fauna is subtropical with a predominance of tropical-subtropical species, 21 species, or 39% of the total species number, subtropical, 14 species, or 26%, and subtropical-boreal (mostly subtropical-lowboreal), 11 species, 21%, totalling 86%. A remarkable feature of the Ulsan Bay fauna is the presence of tropical-subtropical species not found in Yeongil Bay but common in tidal flats and shallow waters of the Yellow Sea and the southern part of Korea. A cold water mass appearing off the southeast coast of Korea near Ulsan in summer seems responsible for the presence of boreal-arctic species in this area.