Development and evaluation of indices to assess the ecological health of the Pahang River, Malaysia

Adnan, Mohd Shalahuddin (2011) Development and evaluation of indices to assess the ecological health of the Pahang River, Malaysia. PhD thesis, Kyushu University.

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Abstract

Water is the essential need for life and all living things need water for living. Recently, the demand for clean and portable water has increased tremendously due to the rapid development and population growth. Since Malaysia has transformed from agriculture country to industrial based country, we are grappling with so many problems such as the increasing of waste, deterioration of water quality, and so on. Due to inadequate technical knowledge, we are not capable to handle and manage the increasing amount of waste. As a result, increasing amount of waste has polluted the water, degraded the habitat as well as caused a massive mortality of fish. Practically in Malaysia, assessment methods were focusing only on certain perspectives, e.g. chemical and physical parameters of water. The integrated assessment (combination between physical, chemical and biological component) to evaluate the health of aquatic environment is scarce. Furthermore, no specific and comprehensive assessment approach was established. For instance, water quality assessment is normally solely based on chemical and physical factors, while biological factor is neglected. This method only provides a partial perspective of water degradation. Moreover, it does not provide any information regarding biota status which becomes one of the main limitations of this method. The main focus of present dissertation is the development of assessment method that could show more sensitivity towards the biological assemblage and at the same time it also could provide additional information to decision maker prior initiating any restoration works. Understanding the effects only from physicochemical parameters is not adequate to evaluate the condition of water environment because it involved the biota. At present, few studies were conducted in this river to evaluate the environment condition of this river, however, none of them focused on the developing of bio-assessment method to evaluate the biotic and abiotic condition in the river. Thus, the present study was designed to investigate the fish composition, assess the water and habitat quality, and integrate this information to develop comprehensive assessment method that is reliable, rapid manner and the results can be easily deliver and present to public. In addition, the development of this assessment is crucial for monitoring and managing our water environment where the threats of biodiversity are tremendously increased especially this river. The Pahang River which is located in the Pahang state, Malaysia was selected as the study area. This river was chosen because it was regarded as the most valuable river in Malaysia that is rich in biodiversity, has great potential of water resources and remarkably contributes to economic growth. Twenty-one sampling sites were designed and monthly surveys were conducted from August 2007 until June 2010 to collect environmental variables as well as fish data. These data will were analyzed and used to evaluate the environmental health in this river. Prior to developing and integrating several indices to measure the ecosystem health, a comprehensive data on aquatic and environmental variables were needed. The fish surveys were conducted to collect biodiversity information on the fish fauna, while biotic variables were collected to monitor the concentration of these variables. From the survey results, not only fish composition are differs between river segments but also fish diversity and richness, where the downstream area were recorded the highest diversity as well as species richness. These results indicate that the diversity and species richness in this river was significantly influenced by river width, altitude, water quality and habitat quality. On the other hand, by using two-way indicator species analysis (TWINSPAN) and multidimensional scaling analysis based on fish occurrences, fish community assemblage pattern can be divided into four groups; (i) upstream Al, (ii) upstream A2, (iii) middle stream, and (iv) downstream stream groups. Further, these segments classification will be utilized to assign scoring criteria for the development of biological index. Subsequently, the combination between water quality index (WQI) and habitat assessment were performed to evaluate the environmental conditions fiom abiotic point of view. The calculations of WQI are based on the procedure proposed by Department of Environment while designation of classes of beneficial uses was based on standard provided by the Interim National Water Quality Standards for Malaysia (INWQS). Six variables were considered as main variables; COD, BOD, TSS, m N , pH and water temperature. Meanwhile for habitat assessment, a method that was developed by Barbour et al. (1999) was used. However, several attributes were modified to fit in with local conditions. Assessment results showed that human activities has deteriorated the water quality as well as degraded habitat quality of this river. As a result, it has significantly impact on fish composition in this river. After all, the combination of these two techniques could widen up our understanding on how aquatic life was affected by water and habitat quality. The Pahang River which is located in the Pahang state, Malaysia was selected as the study area. This river was chosen because it was regarded as the most valuable river in Malaysia that is rich in biodiversity, has great potential of water resources and remarkably contributes to economic growth. Twenty-one sampling sites were designed and monthly surveys were conducted from August 2007 until June 2010 to collect environmental variables as well as fish data. These data will were analyzed and used to evaluate the environmental health in this river. Prior to developing and integrating several indices to measure the ecosystem health, a comprehensive data on aquatic and environmental variables were needed. The fish surveys were conducted to collect biodiversity inforination on the fish fauna, while biotic variables were collected to monitor the concentration of these variables. From the survey results, not only fish composition are differs between river segments but also fish diversity and richness, where the downstream area were recorded the highest diversity as well as species richness. These results indicate that the diversity and species richness in this river was significantly influenced by river width, altitude, water quality and habitat quality. On the other hand, by using two-way indicator species analysis (TWINSPAN) and multidimensional scaling analysis based on fish occurrences, fish community assemblage pattern can be divided into four groups; (i) upstream Al, (ii) upstream A2, (iii) middle stream, and (iv) downstream stream groups. Further, these segments classification will be utilized to assign scoring criteria for the development of biological index. Subsequently, the combination between water quality index (WQI) and habitat assessment were performed to evaluate the environmental conditions from abiotic point of view. The calculations of WQI are based on the procedure proposed by Department of Environment while designation of classes of beneficial uses was based on standard provided by the Interim National Water Quality Standards for Malaysia (INWQS). Six variables were considered is main variables; COD, BOD, TSS, N&N, pH and water temperature. Meanwhile for habitat assessment, a method that was developed by Barbour et al. (1999) was used. However, several attributes were modified to fit in with local conditions. Assessment results showed that human activities has deteriorated the water quality as well as degraded habitat quality of this river. As a result, it has significantly impact on fish composition in this river. After all, the combination of these two techniques could widen up our understanding on how aquatic life was affected by water and habitat quality. After the determination of river classification and understanding the life history of each species, the development of fish characteristics list can be developed. This list considered as the most important data prior developing the IBI because it will be utilized as the main factors in IBI metrics selection. Regarding to the development and calculation of index of biotic integrity (IBT), fifteen metrics were integrated based on fish life history charcteristics such as species richness and composition, intolerant and tolerant species, trophic composition, spawning and habitat preference, and also fish health and abundance. The evaluation results based on the selected metrics seems corresponded well with fish composition, water quality and human impacts. Thus, it was suggested that the integration of selected metrics could be applied to evaluate the environmental conditions for this river because it could provide better evaluation and assessment result compared to single indicator when dealing with complex problems. Even though species diversity in this river is high, commercially exploited edible species are rare due to the increasing of environmental degradation. In addition, the numbers of species that susceptible to biotic and abiotic have also continuously reduced. Thus, immediate solution to control and prevent these species from extinct are needed. One of the promising methods that can be used to monitor the probability of fish occurrences are by modelling. Many researchers have developed a model based on fish data and have suggested that the modelling could contribute in conserving targeted fish and environment condition in general. In this study, four fish species have been chosen to be modeI. The selection of fish species highly depends on their economic values and also was on the targeted list as protected species for Peninsular Malaysia proposed by Department of Fisheries. Statistical analysis known as generalized linear model (GLM) was conducted to model the occurrences of these species with regards to environmental variables. Then, to evaluate the accuracy of model results, area under the curve (AUC) was calculated. Based on the AUC values, all the models results were classified as acceptable and regard as useful application. In summary, this study has demonstrated the environmental variables and human activities have influenced the fish composition assemblage. Based on four assessment methods that were used to evaluate the environmental condition of this river, bio-assessment based on fish data (IBI) provide better assessment results than other assessment methods. These assessment results could provide indispensible information in managing our water environment. Regarding to habitat assessment method and fish-based index, further xii

Item Type:Thesis (PhD)
Subjects:T Technology > TD Environmental technology. Sanitary engineering > TD785-812 Municipal refuse. Solid wastes
Divisions:Faculty of Civil and Environmental Engineering > Department of Water and Environment Engineering
ID Code:3963
Deposited By:Normajihan Abd. Rahman
Deposited On:01 Jul 2013 12:00
Last Modified:01 Jul 2013 12:00

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