Date of Award

1-1-2001

Thesis Type

Masters

Document Type

Thesis

Divisions

Institute for Advanced Studies

Department

-

Institution

Universiti Malaya

Abstract

Three sites on the fringing coral reef flats at Cape Rachado, West Coast Peninsular Malaysia, were selected for the study of seaweed diversity and abundance. Each of these sites was identifiable with exposure to a particular environmental stress. Site A suffered from heavy loads of total suspended solids (TSS) caused by the removal of its adjoining coastal mangrove stand. Site B, by virtue of its accessibility and location on a popular stretch of beach, received a greater number of swimmers and beachwalkers. Water effluent (sewage) outlets from the various resorts lining the coast were observed at sites A and B. Site C was the least exposed to anthropogenic disturbance because of its location further out, at the face of the promontory. The primary objective of this study was to determine the diversity and abundance of the seaweed community at these three sites in relation to water quality parameters. These included temperature, pH, salinity, DO, ammoniacal nitrogen (NH₃-N), dissolved orthophosphate (O-PO₄), 8.nd total suspended solids (TSS). The sub-objectives were to compare the results of this present study to those of the first study conducted at Cape Rachado in 1987/88, to identify the possible causes of changes, and to make recommendations for the management of the coral reef ecosystem with emphasis· on the seaweed community. The method employed in the sampling of seaweeds was the line-transect and systematic quadrat-sampling method. Quadrats were placed systematically along each transect at a distance of 10m a pan. All algal material with holdfasts lying within the 0.09 m² quadrat was removed for identification. The phycological analysis in this study was of species composition, species richness, the Shannon index of diversity (H'), the Evenness Index (J), seaweed dry weight biomass, Sorensen's index of similarity (S), seaweed functional morphologic grouping, species frequency, species dominance and the importance value index (IVI). A total of 81 species was found at Cape Rachado (site A: 54 species; site B: 35 species; site C: 69 species), of which the Rhodophyta constituted the majority. The water quality of site C appears to support a richer, more diverse and evenly spread seaweed community, and with the greatest biomass. In contrast, the seaweed community at site A was the poorest in diversity, evenness and biomass, a condition suggested to be attributed to the high TSS concentration in the waters of this site. Sargassum haccularia was the most important species in terms of frequency and dominance at all three sites. The comparative analysis of the survey of 1987/88 and 1998 showed that all sites had changed significantly in terms of seaweed composition, richness, diversity, evenness and biomass, in varying degrees. The clearest change, however, was the significant increase in species richness at all three sites in 1998, thus arguing for a possible general increase or recruitment of seaweed species at Cape Rachado in the past decade. However, the seaweed community of site A had diminished in terms of biomass and species evenness (J), whilst site C had significant gains in both species richness and diversity (Hl Sargassum oligocys111m, the dominant species found in the survey of 1987/88 was not recorded in the present survey. Instead, Sargassum baccularia was found to dominate the seaweed flora in the survey of 1998. In tenns of water quality, the high TSS load caused by land clearing at site A a decade ago had not been significantly alleviated, and thus, TSS load control was the most important recommended management step for this site.

Initial

snms

Additional Information

Dissertation (M.A) -- Institute for Advanced Studies, Universiti Malaya, 2002

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