Seaweed community of the Merambong shoal,

Abstract: A study on seaweed community encompassing diversity, life form and percentage cover was carried out at the seagrass bed of Merambong shoal, Sungai Pulai estuary, Johore. A total of 30 seaweed species were recorded among seagrasses or on sand and mud substrates. Chlorophyta was recorded with a total of 15 diverse species followed by Rhodophyta 11 species and Phaeophyta 4 species. Seaweeds from the three divisions; Chlorophyta, Phaeophyta and Rhodophyta did not show any distinct zonation. Leaves of Enhalus acoroides, Halophilla ovalis and Halodule uninervis provided refugia for many seaweeds e.g., Bryopsis plumosa, Cladophora prolifera, Dictyota dichotoma, Hydropuntia edulis, Gracilaria fisherii, G. salicornia and Ulva sp. Ulva compressa, Ulva reticulata and Amphiroa fragilissima were attached to mollusc shells or polychaete tubes. Jania decussato-dichotoma, Laurencia sp., and Acanthophora spicifera were observed lying loosely among seagrasses or attached to the sand or mud substrates. Seaweed occurrences differed with months e.g., Ulva reticulata, Halimeda opuntia,Amphiroa fragilissimaand Hydropuntia edulis were found abundant from June to August coinciding with the rainy period. The observations showed seaweeds share and have the adaptability to thrive and even compete with seagrasses, occupying both available living e.g., seagrasses, polychaete tubes or dead structures e.g., mollusc shells, as well as in sand to mud as supports