Dredging and Dumping Impacts on Temporal Variation in Marine Fish
Assemblages, Ghana
Abstract
Fish fauna biodiversity, abundance and distribution pattern are
essential component needed for conservation and management strategies in
any water body. The temporal variations of the fish assemblages in
relation to maritime construction activities are poorly explored in
Ghana. The association between the fish assemblage and construction
activities were examined off the coast of Greater Accra, Ghana. A total
of 37 and 14 species were identified prior and after the dumping
activities at DSA dominated by S. dorsalis and B. auritus
respectively. For the 27 and 24 species recorded before and after
dredging activities at VNB, S. histrio and L. atlanticus
& P. prayensis dominated respectively. SIMPER analysis revealed
that S. micrurum, A. notacanthus and S. dorsalis were the
most discriminating species at DSA while S. hoefleri and L.
atlanticus discriminated most at VNB. Cluster analysis was used to
temporally compare fish assemblage structures in sampling areas at both
sampling sites (DSA and VNB). SimProf and ANOSIM analysis revealed that
sampling location within the sites was not a major factor in changes in
fish assemblages. Species richness and Shannon-Weaver index (H′)
increased significantly after the dredging activities while at the
dumping sites, species richness and Shannon-Weaver index decreased
significantly after the dumping activities. Correspondence Analysis
ordinations (CCA) revealed increase in herbivorous and benthic
invertebrate feeders after the dredging activities while vermivorous and
euryphagus feeders were proportionally high after the dredging
activities. The driving factor influencing the temporal variation in
fish assemblage structure at both sites is probably related to the
dredging and dumping activities which affects the trophic guild of the
species.