Date of Award

1-1-2001

Thesis Type

Masters

Document Type

Thesis

Divisions

Institute for Advanced Studies

Department

-

Institution

Universiti Malaya

Abstract

Tasek Bera, located in southwest of Pahang state, is Malaysia's largest freshwater swamp and lake system. It is one of the remaining examples of a lowland alluvial riparian swamp system. Tasek Bera was designated as Malaysia's first "Wetlands of International Importance" under the Ramsar Convention in November 1994. The water quality of Tasek Bera was monitored from April to October 1998 to assess environmental conditions affecting phytoplankton assemblages. Measurement of physical and chemical parameters at selected sites ranged as follows : pH (4.45 to 6.73), temperature (25.3 to 33.3 °C), dissolved oxygen (0.40 to 5.80 mgL⁻¹), water depth (0.15 to 5.40 m), Sccchi depth (0.14 to 2.19 m), conductivity (11.20 to 129.60 µS.cm⁻¹), dissolved orthophosphate (0.0000 to 0.0095 mgL⁻¹), nitrate (0.000 to 5.600 mgL⁻¹) and ammoniacal-N (0.000 to 2.9132 mgL⁻¹). In general, most of the sites are relatively undisturbed. However, nitrate, ammoniacal-N, conductivity and turbidity were quite high at some of the sites. A total of 326 species of phytoplankton, including 42 unidentified species, were found in the study. This consisted of 150 species of Chlorophyta, 90 species of Chrysophyta, 36 species of Euglonophyta, three species of Pyrrhophyta, three species of Xanthophyta and two species of Cyanophyta. Chlorophyll-a concentration ranged from 0.000 to 7.3437 mgm⁻³ while primary productivity was measured at a maximum of 0.8573 mgO₂⁻¹1⁻¹hour⁻¹ . Cell counts ranged from 1.34 to 400.275 cells.L⁻¹.

In the two-way analysis of variance, primary productivity and transparency were Significantly different among sampling stations. Chlorophyll-a levels, Shannon­Weiner Diversity Index (H') values, Margalers Species Index (d) values, Species Evenness (J) values, phytoplankton cell counts, conductivity and pH were significantly different among sampling occasions. Multiple regression analysis showed that pH and nitrate contributed significantly to chlorophyll-a concentration. Conductivity contributed significantly to Shannon-Weiner Diversity Index (H') values, Margalers Species Index (d) values, Species Evenness (J) values and phytoplankton cell counts. Water depth, transparency and temperature contributed significantly to primary productivity. Cluster analysis was used to segregate sampling stations based on biotic parameters as well as environmental parameters. Pollutant-tolerant species identified were Trachelomonas sp., Gomphonema parvulum, Navicula sp., Peridinium sp. and Euglena acus. This research looks into the feasibility of using phytoplankton assemblages as indicators of environmental change due to anthropogenic effects, particularly of agricultural activities.

Initial

snms

Additional Information

Dissertation (M.A) -- Institute for Advanced Studies, Universiti Malaya, 2001.

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