Citation: Rosenberg, R. 1980 Effects of oxygen deficiency on benthic macrofauna in fjords. In H.J. Freeland, D.M. Farmer & C.D. Levings (eds), , pp. 499-514. Plenum Press, New York
Number of Pages: 16
Series Title: Fjord oceanography
Keywords: Baltic, Benthos, Cork, Denmark, Fauna, Lough Hyne, Marine, Marine Inlet, Norway, Reserve, Sweden, Water quality, Zonation
Abstract: Benthic faunal reactions to oxygen deficiency in ten fjords and estuaries in northern Elviene are reviewed. The areas are: Byfjord (Sweden), Loch Ine (Ireland), The Limfjord (Denmark), locations in the Baltic and The Idefjord (Sweden-Norway). Chosen areas exhibit both permanent and temporary oxygen deficiency due to organic enrichment and/or geomorphological conditions. Number of species, abundance, biomass, and faunal composition are given in relation to oxygen concentration. Results show that the measured faunal parameters do not change gradually with oxygen concentration, but abruptly at approximately 2 mg oxygen per litre. Benthic faunal reactions to oxygen deficiency suggest the following grouping: (1) Non-tolerant species; most species (2) Tolerant species; mainly molluscs (3) Transitory opportunists; pioneer polychaete colonists appearing when conditions improve (4) Transitory emigrants; mobile species. The missing macrofaunal biomass in some waters around Scandinavia is roughly estimated and it is concluded that oxygen depletion due to geomorphological characteristics of water bodies wipes out significantly more animals than similar effects caused by organic pollution.