Ecological Characteristics Of The Littorial Fauna At Tubli Bay, Bahrain

Abstract

Papers presented at The gulf symposium on Environmental biology, University of Qatar, 7-9 May 1994 *********** The intertidal fauna inhabiting a wide range of habitats at Tubli, an inshore bay on the eastern part of Bahrain has been surveyed, for the first time, over a period of several seasons. Quantitative and qualitative samplings have resulted in the collection of 29 species and made it possible to separate natural from unnatural variability in the littoral fauna caused by waste water outfall from sewage treatment plants and brackish water discharges from farms on the adjacent coastal area. Around the outfall, the littoral fauna was greatly reduced in the number of species and individuals. Shore crabs were the dominant group, forming more than 50% at the transect adjacent to the waste water outfall. Gastropods dominated the fauna at other transects; Pirnella conica was found to comprise more than 90% of the fauna. Overall, summer months were found to support greater number of individuals, indicating that spawning and recruitment occur in warmer periods of the year. Availability of appropriate substrate and ability to tolerate reduced salinity, high nutrient input, greater trace metal concentration and siltation seem to control the type and distribution of littoral fauna at Tubli Bay.