Intertidal zonation of live benthic foraminiferal assemblages from mangrove environments around south-west Penang Island, Peninsular Malaysia

Abstract

Abstract Studies on benthic foraminifera were conducted in the mangrove forests of Teluk Tempoyak, Pulau Betong and Kuala Sungai Pinang, Penang Island, Peninsular Malaysia to examine species composition and distribution patterns in different intertidal zones. Twenty-eight live benthic foraminiferal species were successfully identified at the study locations, predominantly species with agglutinated tests. Assemblages in Pulau Betong and Teluk Tempoyak were dominated by similar species such as Ammonia aoteana, Elphidium hispidulum, Elphidium neosimplex and Trochammina inflata, while Kuala Sungai Pinang comprises a high number of Trochammina inflata and Arenoparrella mexicana. Three species, Aubignyna perlucida, Elphidium neosimplex and Elphidium sandiegoense, were recorded for the first time in Malaysian mangrove forests. Principal component analysis showed that sediment type and organic matter content were the dominant parameters that explained the variation of environmental gradient. Canonical correspondence analysis of these parameters with benthic foraminiferal species indicated that sand particles influenced distribution of the hyaline tests. Species with agglutinated tests were abundant in sediment with rich organic matter in combination with high silt and clay content. Species with hyaline tests dominated lower intertidal zones, while those with agglutinated tests inhabited the area from the middle to upper intertidal zones. This distribution pattern of benthic foraminiferal species mirrored patterns found at other local and global mangrove locations.