Benthic zonation of the Eastern Gotland Basin, Baltic Sea

Abstract

In this paper recent benthic biological studies in the Eastern Gotland Basin area of the Baltic Sea are summarised. A general pattern of vertical distribution of macrofauna is presented and special reference is made to sharp temporal changes in macrofauna of deeper, subhalocline areas of the basin. Information on faunal sediment reworking ability is compiled. The environmental factors driving benthic zonation are discussed and the vertical benthic zones are defined on the basis of their major biological and abiotic features. This analysis shows that due to sharp gradients in environment and clear differences in composition of macrofauna, the ecological functioning of the Eastern Gotland Basin benthic zones is clearly different. Therefore, in the biogeochemical models of benthic-pelagic interaction, these zones (together with water layers they underlie) should be treated separately, as different sub-systems.