The Intertidal Biota of Volcanic Yankich Island (Middle Kuril Islands)

Abstract

A description of the intertidal biota of volcanic Yankich Island (Ushishir Islands, Kuril Islands) is given. The species composition and vertical distribution pattern of the intertidal communities at various localities are described in relation to environmental factors, such as nature of the substrate, surf conditions and volcanic vent water. The macrobenthos is poor in the areas directly influenced by high temperature (20-40C) and high sulphur content. There are no marked changes in the intertidal communities in the areas of volcanic springs that are characterised by temperature below 10C and by the absence of sulphur compounds. In general, the species composition and distribution of the intertidal biota are ordinary for the intertidal zone of the middle Kuril Islands. But there are departures from the typical zonation of the intertidal biota. Also, mass populations of Balanus crenatus appear.