Seagrass mapping and distribution in relation to water quality using GIS in Sungai Johor, Peninsular Malaysia / Noor Aini Ahmad

Seagrass meadows are noted for their extremely high productivity and contribution of valuable ecosystem functions and services to coastal zone. Seagrasses which are vulnerable to the changes of water and environmental quality are increasingly threatened by human activities resulting in a deterioration of water quality. An environmental study on seagrass was conducted at Sungai Johor, Peninsular Malaysia. The purpose of this study was to examine the relationship between species diversity and distribution of seagrasses and various environmental (water quality) factors. Three (3) seagrass species were found along Sungai Johor which identified as Halophila ovalis, Halophila spinulosa and Enhalus acoroides. Halophila ovalis which occur at all study sites was the most dominant species. The study gives a conclusive results that water quality has significant relations and effects to the seagrass present and distribution in the study area. Seagrass areas have a greater value for salinity, conductivity and Total Nitrogen (TN), while having a very much lower value for Total Suspended Solid (turbidity), E. coli and Cuprum, compared to the area without seagrass. In terms of seagrass diversity and abundance, the most significant water quality parameters are those that influence light penetration and aquatic nutrient levels. Tanjung Kopok (S3) which has the best water clarity exhibit the highest DW biomass, whereas Tanjung Surat (S4) which has the most turbid water exhibit the lowest DW biomass and species diversity; and Pasir Gogok (S5) which has the highest TN value exhibit the highest number of species, thus S4 which has the lowest TN value exhibit only one species in the area. There is no doubt about the capabilities and advantages of Geographical Information Systems (GIS) which were demonstrated in this study, as a powerful tool in environmental research and coastal management