Physical characteristics and nutrients status off Pulau Besar, Malacca and Tanjung Tuan, Negeri Sembilan, Malaysia: A preliminary study

Abstract

Degradation of coastal water quality is one of the major concern in the Malacca Strait since this area is one of the most important fishing ground in Malaysia. Despite being great in the fishery industry, Malacca and Negeri Sembilan somehow recorded the lowest marine fishes landing, which raises a question about dynamics of this area. It is therefore, a preliminary study of the physical properties and nutrient concentrations carried out from 27 March to 4 April 2016 at the coastal water off the southern west coast of Peninsular Malaysia, specifically at Pulau Besar, Malacca and Tanjung Tuan, Negeri Sembilan. Data for temperature, salinity, and dissolved oxygen (DO) was acquired by using Conductivity, Temperature, and Depth (CTD) probe. Meanwhile, nutrient concentrations determination in this study was done by using a Westco Smartchem 200 Discrete Analyser, according to the procedure adopted from United States Environmental Protection Agency (USEPA). In general, results of this study indicated the coastal stations were characterised with cooler, less saline, and high DO waters than stations away from coast. Large sea surface heating and weak winds were determined as the causative factors affecting dynamics of water column at the study area. At nearshore area, temperature, salinity, and DO variability were modulated by degree of freshwater intrusion. High nutrient concentrations at the stations closer to the coast was believed to be associated with river outflow, which acted as the main source of nutrients supply in this area. Comparison to previous study had shown that nutrient concentrations in this research were low, which could contribute to an insight on declining marine fish catches in these two states. With regard to Malaysian Marine Water Quality Criteria and Standard (MWQCS), mean nutrient concentrations at the study area were in Class 1, which are suitable for marine parks and marine protected areas conservation. Regardless of limited scope, the outcome of this study is believed to be a good baseline reference for future studies seeking to understand coastal dynamics.