Spatial and Temporal Variations of Marine Benthic In-fauna Community in Northern and Southern Areas of the Kingdom of Bahrain

Abstract

The in-fauna community inhabiting the surface sediments in the Bahrain waters during 2007-2008 was investigated to describe the spatial and temporal variations between and within Northern and Southern areas. Using a 0.05 m2 van veen grab, samples were collected from 12 sampling stations: 6 stations at each Northern and Southern waters. The samples were collected during Summer and Winter to compare the in-fauna species composition on seasonal basis at each area. In situ water analysis (temperature, salinity, turbidity, pH, dissolved oxygen and depth) and the sediment grain size analysis were carried out at same stations of in faunal samples in order to identify potential environmental key factors causing temporal and spatial variations of in-fauna assemblage. Based on species composition, in-fauna community patterns were identified and evaluated by multivariate analysis Multidimensional Scaling (MDS) using PRIMER V6. A total of 5075 specimens represented by 186 taxon were collected during the study period. Generally, the infauna abundance and number of species in the Northern area was higher than the Southern area and seasonally the samples collected in Summer were relatively more abundant than those collected in Winter. The BIOENV results revealed that the water depth and turbidity are the most influential parameters causing spatial variations of in-fauna community within Northern and Southern areas. On temporal basis, temperature found to be the factor determining major part of the temporal variations within stations associated with Southern area, however turbidity was the influential parameter of temporal variations for stations within the Northern area. On the other hand, the salinity found to be the influential factor affecting the majority of spatial variation between Northern and Southern in-fauna species composition. The present study provides a database on part of marine biodiversity representing a background on benthic community in Bahrain that can be used as a biological indicator to evaluate potential environmental impacts pertaining to developmental projects particularly dredging and reclamation works in coastal and offshore regions.