Diversity of Fish Fauna and Water Quality in Murum River Below Murum HEP, Belaga, Sarawak

Yeow Seh Keat

(44688)

Bachelor of Science with Honours (Aquatic Resource Science and Management)

2016

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Diversity of Fish Fauna and Water Quality in Murum River Below Murum HEP, Belaga, Sarawak

Yeow Seh Kest (44688)

This dissertation is submitted in partial fulfillment of the requirements for the degree of

Bachelor of Science with Honours in Aquatic Resource and Science Management

Faculty of Resource Science and Technology

Universiti Malaysia Sarawak

2016

DECLARATION OF AUTHORSHIP

I, YEOW SEH KEAT declare that the final year project report entitled:

Diversity of Fish Fauna and Water Quality in Murum River Below

Murum HEP, Belaga, Sarawak

and the work presented in the report are both my own, and have been generated by me as

the result of my own original research. I confirm that:

" this work was done wholly or mainly while in candidature for a research degree

at this University;

" where I have made corrections based on suggestion by supervisor and examiners,

this has been clearly stated;

" where I have consulted the published work of others, this is always clearly

attributed;

" where I have quoted from the work of others, the source is always given. With

the exception of such quotations, this report is entirely my own work;

"I have acknowledged all main sources of help;

" where the thesis is based on work done by myself jointly with others, I have made

clear exactly what was done by others and what I have contributed myself;

" none of this work has been published before submission

Signed:

Aquatic Resource Science and Management Department of Aquatic Science Faculty of Resource Science and Technology Universiti Malaysia Sarawak (UNIMAS)

Date: -27% Just 3016 t

I

Acknowledgement

I would like truly thank my supervisor, Professor Dr. Lee Nyanti @ Janti ak Chukong for his

advice, guidance, suggestion, knowledge and constructive criticism which have helped me

become a better person in work wise. Your commitment to this project is second to none.

I would like to extend my acknowledgement and gratitude to the staff of the Department of

Aquatic Science, especially Mr. Zaidi Ibrahim, Mr. Benedict anak Samling, Mr. Richard Toh,

and Mr. Mustafa Kamal for their effort in helping us throughout the final year project, whether

in the field or in the laboratory.

Matchless appreciation and thanks to Ms. Angie Sapis for spending her time and effort in

helping me throughout the final year project including guiding me in the field until the

completion of this thesis. Your support has made me a stronger person and I will forever be

grateful.

Next, the financial support by Sarawak Energy Berhad through research grant no

GL(F07)/SEB/4A/2013 (24) is gratefully acknowledged.

Last but not least, I would also like to extend my deepest appreciation to my family, for their

support and understanding. Additionally, I wish to thank my fellow friends which is under the

same supervisor for their assistance, ideas, information and knowledge for helping me to

complete the project.

II

Diversity of Fish Fauna and Water Quality in Murum River below Murum HEP, Belaga, Sarawak

Yeow Seh Keat

Aquatic Resource Science and Management Faculty of Resource Science and Technology

Universiti Malaysia Sarawak

ABSTRACT

Fish survey and selected water quality parameters sampling were conducted on 231 to 251 of August 2015 and 71 to 91h November 2015 from the downstream of Murum Hydroelectric Powerhouse until Murum River mouth. Currently, there is no information regarding the fish fauna composition at this stretch of the river. Therefore, this

study was conducted to determine the effects of water discharge from Murum Powerhouse on the fish fauna and water quality of Murum River below the powerhouse. A total of 270 individuals fish were caught comprising of 21 species from 6 families. The highest number of individuals caught was Cyclocheilichthys apogon (38.57 %),

and followed by Kryptopterus lais (10.57 %). The highest species diversity was recorded in station 3 in August 2015 with a value of 1.96, and station 4 in November 2015 with a value of 1.87. The Length-Weight Relationship

of 5 selected fish species showed that only Barbonymus schwanenfeldii has positive allometric growth (3.19 ± 0.43) but C. apogon (2.91 ± 0.12) (K= 1.07) and Puntioplites waandersii (2.82 ± 0.15) (K=1.08) showed negative allometric growth. Female Barbonymus schwanenfeldii (4.39±1.46) and both sexes of Pangasius micronemus (female = 5.23±2.46, male = 3.90±3.19) recorded relatively higher GSI value, which indicates that the species

may be reproductively active in the area. The HSI value for the combined trips ranged from 0.06 to 0.35 for 15

recorded species. Water quality readings recorded throughout the study showed that temperature ranges from

26.81 °C to 31.38 °C, dissolved oxygen ranges from 4.39 mg/L to 5.97 mg/L, pH ranges from 6.06 to 6.85,

conductivity ranges from 31.28 µS/cm to 33.08 µS/cm, turbidity ranges from 0.83 NTU to 84.63 NTU, and transparency ranges from 39.08 cm to 164.96 cm. The impoundment of Murum River may have affected fish fauna composition with reduced diversity along the stretch of river below the HEP due to changes in water

quality in the surrounding area.

Keyword: Fish fauna composition, water quality, hydroelectric powerhouse.

ABSTRAK

Kajian ikan dan kualiti air yang terpilih telah dijalankan dari 23 bb hingga 25 bb Ogos 2015 dan 7"b hingga 9hb November 2015, dari hiliran stesen penjanaan kuasa hidroelektrik Murum, hingga muara Sungai Murum. Sehingga ini, tiada maklumat mengenai komposisi fauna Man di sepanjang sungai tersebut. Oleh itu, kajian ini dijalankan untuk menentukan kesan pelepasan air daripada stesen penjanaan kuasa kepada fauna ikan dan kualiti air Sungai Murum, bawah stesen penjanaan kuasa. Sejumlah 270 ekor ikan yang telah ditangkap terdiri daripada 21 spesis daripada 6 famili. Bilangan ekor ikan tertinggi yang ditangkap ialah Cvclocheilichthvs

apoQon (38.57 %), dan diikuti oleh Krvntopterus lais (10.57 %). Index kepelbagaian spesis yang tertinggi telah dicatatkan di Stesen 3 pada Ogos 2015 dengan nilai sebanyak 1.96, dan Stesen 4 pada November 2015 dengan

nilai sebanyak 1.87. Hubungkait panjang-berat (LWR) lima spesis ikan yang terpilih menunjukkan hanva Barbonvmus schwanenteldii mempunyai pertumbuhan alometrik positif (3.19 ± 0.43) tetapi Cvclocheilichthvs

apOYOn (2.91 ± 0.12) (K=1.07) dan Puntioplites waandersii (2.82 10.15) (K= 1.08) menunjukkan pertumbuhan

alometrik negatif. Barbonvmus schwanen eldii betina (4.39±1.46) dan kedua-dua jantina Pangasius micronemus (betina = 5.23±2.46, jantan = 3.90±3.19) mencatatkan nilai GSI yang lebih tinggi, menunjukkan spesis tersebut

mungkin aktif dalam persenyawaan di kawasan tersebut. Ni/ai HSI untuk kedua-dua kajian tersebut mempunyai julat daripada 0.06 hingga 0.35 untuk 15 spesis yang direkodkan. Bacaan kualiti air yang direkod pada keseluruhan kajian ini menunjukkan julat suhu 26.81 °C hingga 31.38 °C, julat oxygen terlarut daripada 4.39

mg/L hingga 5.97 mg/L, julat pH daripada 6.06 hingga 6.85, julat konduktiviti daripada 31.28 PS/cm hingga 33.08 µS/em, julat kekeruhan daripada 0.83 NTU hingga 84.63 NTU, dan julat kejernihan daripada 39.08 cm hingga 164.96 cm. Penakungan Sungai Murum mungkin telah mengakibalkan kesan buruk kepada komposisi fauna ikan seperti pengurangan kepelbagaian di sepanjang sungai tersebut, terutamanya di bawah stesen penjanaan kuasa disebabkan oleh perubahan kualiti air di kawasan sekeliling.

Kata kunci: Kualiti air, komposisi fauna ikan, stesen penjanaan kuasa hidroelektrik.

III

Pusat K ̀ t, idmai tViakiumat Aicatleur' UNIVERSiTt MALAYSIA SARAWAv.

Table of Contents

Page Declaration I

Acknowledgement II

Abstract III

Abstrak III

Table of Contents IV

List of Tables VI

List of Figures VII

List of Abbreviations VIII

1.0 Introduction 1

2.0 Literature Review 3

2.1 Freshwater Fish Fauna Diversity 3

2.2 Modification of Natural Ecosystem 3

2.3 Threats of Dam to Freshwater Fishes at Downstream Areas 4

2.4 Water Flow 4

2.5 Effects of Regulated River on Spawning Behavior of Fish 5

2.6 Water Quality Parameters 6

2.7 Length-Weight Relationship 7

2.8 Feeding Habits 8

3.0 Materials and Methods 9

3.1 Study Site 9

3.2 Water Quality 11

3.2.1 Water Quality Parameters measured in situ 11

3.2.2 Water Quality Parameters measured ex situ 12

3.2.2.1 Total Suspended Solids (TSS) 12

3.2.2.2 Biological Oxygen Demand in 5 days (BOD5) 12

3.2.2.3 Chlorophyll-a 13

3.3 Fish Samples Collection, Measurement and Preservation 14

3.4 Fish Identification 15

3.5 Length-Weight Relationship (LWR) 15

3.6 Gonadosomatic Index (GSI) and Hepatosomatic Index (HSI) 16

3.7 Stomach Content 16

3.8 Ecology Indices 17

IV

3.9 Statistical Analysis

4.0 Results

4.1 Water Quality Parameter Measured in situ

4.1.1 Temperature

4.1.2 pH 4.1.3 Dissolved Oxygen (DO)

4.1.4 Transparency

4.1.5 Conductivity

4.1.6 Turbidity

4.2 Water Quality Parameter Measured ex situ

4.2.1 Total Suspended Solids (TSS)

4.2.2 Biological Oxygen Demand in 5 Day

4.2.3 Chlorophyll-a

4.3 Fish Identification

4.3.1 Fish Caught in August 2015

4.3.2 Fish Caught in November 2015

4.3.3 Pooled Fish Data

4.4 Length-Weight Relationship

4.5 Gonadosomatic Index (GSI)

4.6 Hepatosomatic Index (HSI)

4.7 Stomach Content Analysis

4.8 Diversity, Richness and Evenness Indices

4.9 Principle Component Analysis

5.0 Discussion

6.0 Conclusion and Summary

7.0 Recommendation

8.0 References

9.0 Appendix

V

List of Tables

Table no. Caption Page

Table 1. National Water Quality Standards For Malaysia. 7

Table 2. Coordinates of Stations. 9

Table 3. List of fish species, number of individuals caught (N) and percentage 30 (%) from 4 stations during August 2015 trip.

Table 4. List of fish species, number of individuals caught (N) and percentage 33 (%) from 4 stations during November 2015 trip.

Table 5. List of fish species, number of individuals caught (N) and percentage 36 (%) from 4 stations during November 2015 trip.

Table 6. Length-weight relationship of five selected species found throughout 40 the study.

Table 7. List of fish species, number of individuals (N), average Gonadosomatic 40 Index (GSI) (%) and standard deviation (SD) from the 4 stations (pooled data).

Table 8. List of fish species, number of individuals (N), average Hepatosomatic 41 (HSI) (%) and standard deviation (SD) from the 4 stations (pooled data).

Table 9. Frequency occurrence of different food items found in the stomachs of 42 three dominant fish species.

Table 10. Total mass (g) and mass method of different food items found in the 43

stomachs of three fish species.

Table 11. Species Diversity, Species Richness and Species Evenness at the 4 44 stations of the study area in August 2015 and November 2015.

Table 12. Summary of Principal Component Analysis (PCA) for fish species and 45

environmental variables at all sampling stations in August 2015 and November 2015.

I

VI

List of Figures

Figure no. Caption Page

Figure 1. The map of Murum River and sampling stations. 10

Figure 2. Mean temperature at 4 station in Murum River, Below HEP. 19

Figure 3. Mean pH at 4 stations in Murum River, below HEP. 20

Figure 4. Mean DO of 4 stations in Mumm River, below HEP. 21

Figure 5. Mean transparency recorded at 4 station of Murum River, below HEP. 22

Figure 6. Mean conductivity recorded for 4 stations in Murum River, below HEP. 23

Figure 7. Mean turbidity recorded at all 4 stations in Murum River, below HEP. 24

Figure 8. Mean of Total Suspended Solids (TSS) for 4 stations in Mumm River, 25 below HEP.

Figure 9. Mean of Biological Oxygen Demand in 5 days (BOD5) for 4 stations in 26 Murum River, below HEP for both trip.

Figure 10. Mean Chlorophyll-a recorded for 4 stations in Murum River, below 27 HEP.

Figure 11. LWR for Barbonymus schwanenfeldii for August 2015 and November 37 2015 combined.

Figure 12. LWR for Cyclocheilichthys apogon for August 2015 and November 38 2015 combined.

Figure 13. LWR for Hampala macrolepidota for August 2015 and November 2015 38 combined.

Figure 14. LWR for Puntioplites waandersii for August 2015 and November 2015 39

combined. Figure 15. LWR for Pseudolais micronemus for August 2015 and November 2015 39

combined.

Figure 16. Bi-plot PCA ordination of 9 visible water quality parameters and fish 46

assemblages at 4 stations in combined trips with abbreviation code: BSCH (Barbonymus schwanenfeldii), CCHT (Cyclocheilichthys apogon), HNEG (Hemibagrusnegriceps), HPLA (Hemibagrus planiceps), HMAC (Hampala macrolepidota), KLA (Kryptoterus lais), KYA (Phalacronotus apogon), KYB (Kryptopterus bicirrhis), LBFA (Labiobarbus fasciatus), LBBO (Lobocheilos bo), LBFE (Lobocheilos falcifer), LSET (Luciosoma setigerum), LTRI (Luciosoma triinema), MERY (Mastacembelus erythrotaenia), OVT (Osteocheilus vittatus), OANO (Oxygaster anomalura), ONI (Oreochromis niloticus), PMAC (Pangasius macronema), PEMIC (Pseudolais micronemus) PW (Puntioplites waandersii), and TDOU (Tor douronensis).

VII

List of Abbreviations

HEP Hydroelectric Powerhouse

TSS Total Suspended Solids

BOD5 Biological Oxygen Demand

CHL-a Chlorophyll-a

DO Dissolved Oxygen

GSI Gonadosomatic Index

HSI Hepatosomatic Index

BW Body Weight

SL Standard Length

TL Total Length

H' Shannon-Weiner's Index

D Margalef's Species Richness Index

J' Pielou's Eveness Index

VIII

1.0 Introduction

Malaysia have huge amount of freshwater resources that are contributed by high annual

rainfall that flows through river systems. There are 184 major river basins in Malaysia that

majority of the freshwater flows through (Department of Irrigation and Drainage, 2016).

Rajang River, which is the major river basin in Sarawak flows from the Iran Mountains

towards southwest to Kapit for 563 km and ends up in the South China Sea (Encyclopedia

Britiannica, 2015).

The Rajang River provide habitats to 164 fish species as reported by Parenti and Lim

(2005). Fish fauna studies in Sarawak had been documented by several researches such as

Watson and Balon (1984) in Baram River, Nyanti et al. (1995) in Upper Rajang River,

Nyanti et al. (1999) in Bario, Kelabit Highlands, Nyanti et al. (2006) in Loagan Bunut

National Park, Khairul Adha et al. (2009) in Batang Kerang, and Jongkar (2013) in Padawan

Limestone.

Dams are generally built for electricity generation and flood control (Rosenberg et al.,

1997). Two dams were built along the upper region of the Rajang River to provide energy

and generate income (Sarawak Integrated Water Resources Management, 2008). Murum

Dam, Belaga, located upper region of the Murum River is the second hydroelectric project

developed by Sarawak Energy after Bakun Dam. This dam has a height of 141 meter, a

catchment area of 2750 km2 and a reservoir size of 245 km2 (Sarawak Energy, 2013).

Impoundment of the dam started on 21 Sl September 2013 reaching full supply level estimated

to be around 540 m above sea level. The dam started operation in August 2014 (RECODA,

2013; Sarawak Integrated Water Resource, 2008). As a result those dam constructions, the

impacts affecting the environment are measurable (McAllister et al., 2001). Some of the

impacts are alteration of animal habitats, altered water temperature, blockage of nutrient

I

flow and loss of fish species (Sovacool & Bulan, 2011). The area below the dam, which is

believed to be affected the most by the change in water flow, will have changes on its water

quality. Deterioration of water quality will change the biota composition in the aquatic

ecosystem (Dudgeon et al., 2005). Therefore, water quality analysis is also important and

must be done as a step to identify the causes of aquatic biota changes.

Currently, there is no of information regarding the diversity of fish fauna recorded at

Murum River, below Murum Dam. The lack of information suggests that there is a need to

document the species diversity at the site. Therefore, the objectives of this research were to:

1. record the fish fauna composition in Murum River, below Murum Dam,

2. document the selected water quality parameters in Murum River, below Murum

Dam,

3. examine the relationship between selected water quality parameters with the fish

fauna diversity, and

4. describe the diet of selected fish species in Murum River, below the dam.

2

2.0 Literature Review

2.1 Freshwater fish fauna diversity

Malaysia's freshwater ecosystem holds up to over 639 species of fish fauna

(FishBase, 2014). A total of 260 freshwater fish species were reported in Peninsular

Malaysia (Kottelat & Whitten, 1996). In East Malaysia, Kottelat and Lim (1995)

documented almost 250 fish species in Sarawak and Brunei. In Sarawak's main river basin,

the Rajang Basin, hold at least 164 species of freshwater fish (Parenti & Lim, 2005).

Cyprinids are especially abundant in Peninsular Malaysia which out-numbered other

family in the country (Cranbrook & Furtado, 1988). A study done in Sarawak by Khairul

Adha et al. (2009) in the brown waters of Batang Kerang, shows the number of cyprinids

(63.8%) dominates other fish species.

2.2 Modification of natural ecosystem

Dams are man-made structures that are used for various purpose such as flood

control, hydropower generation, and irrigation (Seo, 2008). Introduction of dams changes

the water flow and thermal conditions, changes the habitat condition of freshwater

organisms, and also changes the structure and composition of biological communities in

natural streams or river (Chu et al., 2015). Seo (2008) mentioned that dams changes the

existing water system either streams or rivers from lotic to a lentic and further inundate the

surrounding area. The water system then causes habitat loss resulting in change of migratory

pattern and fish assemblages which are obvious (Ho, 2014). When a dam is first introduced

to a riverine system, deterioration of the surrounding water quality is unavoidable and will

result in certain loss of species (Agostinho et al., 2008). However, after the filling phase has

ended, the fish community will begin to adapt themselves into the new condition.

a

3

2.3 Threats of Dam to Freshwater Fishes Downstream

Dams will reduce the necessary nutrient and condition needed to maintain the fish

diversity downstream (Merona et al., 2005). The authors also mentioned that minimal

fluctuation of water volume will decrease the diversity due to increase in predation.

Discharge for dam more than 15 in may cause downstream fish fauna diversity to decline

due to stratification of water (FAO, 2001). The deep cooler water, which is anoxic, will kill

those species which live in warmer waters. Some endemic species which are at the

downstream may face extinction due to difficulty in adaptation. When the system is changed

and not in equilibrium, survival of endemic species is at risk.

Diversity of the altered area may experience biotic homogenization as an act to

balance the ecosystem. Biotic homogenization refers to the reduction of species diversity in

an area (Vitule et al., 2012). It is formed through non-endemic species being introduced to

a water system and/or loss of endemic species from its natural habitat.

2.4 Water Flow

Dams were generally built for socio-economic purposes which are expected to provide

resources and services to people and the industry (FAO, 2001). Many dams around the world

are built to serve the same purposes. There are positive and negative effects of the

implementation of dams to the environment. One significant impact of the dam construction

to the environment is the alteration of water flow regime downstream. Based on a research

by Garcia et al. (2010) at Pangue and Ralco Dams located at the upper region of Biobio

River basin, in central Chile, the downstream environment changed in two ways; (i) the

annual hydrological regime has been altered and flattened due to the water storage capacity

of Ralco Dam, and (ii) minimum fluctuation of flow from the mean flow. Both of the effects

happen due to wrong prediction of consequence from the EIA report.

4

UIYIVEltSLTI MALAYSIA SARAWAh

Water bodies which is trapped upstream in the reservoir, when released to the

downstream can have negative effect to the surrounding environment. According to Baxter

(2005), environmental effects to the downstream community when release of water from

upstream includes destruction of spray-zone due to diversion of rainwater, increase

sedimentation which will lead to higher phytoplankton growth, stratification of water

temperature; cold water at the bottom of the reservoir, and change in density of water. In

some cases, DO level is greatly reduced to zero near the 5m depth in reservoirs. According

to Nyanti et al. (2012), the DO level at Bakun Dam is high near the sub-surface level but

plummeted to near zero between the depths of 2 to 4 m, fifteen months after the dam has

been impounded.

2.5 Effects of regulated river on spawning behavior of fish

Spawning behavior of fish are controlled by the environmental conditions

(Steffensen et al. 2014). Fishes depends on the riverine system-floodplain connection to

stimulate their spawning. Floodplain provides a habitat or spawning ground and is also

important food source to fish of all size (FAO, 2001). Flow of river that is similar to the

fish's response will trigger spawning. An example provided by Baumgartner et al. (2014)

reported that golden perch (Macquaria ambigua perchichthyidae) require two conditions,

which are temperature and water flow to stimulate the spawning sequence. They also

mentioned that different species requires different condition to show responses. Therefore,

it is believed that fishes will only show response to spawning when the condition meet the

requirements.

Implementation of dams affects the natural flooding process (Rosenberg eta!., 1997).

Due to its function, which is flood prevention by storing water in the reservoir, fish at the

downstream region will not be stimulated naturally. As a result, regulation of water by

discharge from dams reduces flooding recurrence which is important for transporting of eggs

and juvenile fishes, and the availability for food and nutrient (Rosenberg et al., 1997).

2.6 Water Quality Parameters

Water makes up almost 70% of Earth's surface. Freshwater accounts only up to 2.5

% the world's water resource (USGS, 2015). Sources of freshwater are naturally from rain

and groundwater. In order for the living organism to utilize the water, water quality is

important to maintain an equilibrium in the body. Certain water quality parameters such as

pH, depth, temperature, dissolved oxygen (DO), BOD, turbidity, total suspended solids

(TSS) and also transparency have standards and guidelines for protection and maintenance

of aquatic organisms (USGS, 2001).

A study conducted in Kerian River tributaries by Zakeyudin et al. (2012), showed

that in a natural river, the ranges of water quality parameters are such as dissolved oxygen

(DO) (3.77-8.34 mg/L), pH (5.64-6.22), temperature (21.82-28.29 °C), and conductivity

(40.9-246.47µS/cm). In another case in San Lorenzo River, Costa Rica by Chaves-Ulloa et

al. (2014), reported that temperature differences is obvious below the dam, with average of

1.28°C higher above the powerhouse.

Based on Department of Environmental (2006), National Water Quality Standards

for Malaysia, water quality parameters in class I are considered unpolluted. The water quality

underclass IIA and IIB are considered slightly polluted. However, the water quality for class

III to class V is considered polluted. The values of selected water quality parameters are as

follow:

6

Table 1. National Water Quality Standards for Malaysia.

Class Parameters (Unit)

I IIA IIB III IV V

pH 6.5-8.5 6-9 6-9 5-9 5-9 <5

Normal Normal + Temperature (°C) 25-28°C - - - + 2°C 2°C

Dissolved Oxygen 7 5-7 5-7 3-5 <3 <1

(DO) (mg/L)

Biological Dissolved 1 3 3 6 12 > 12

Oxygen (BOD) (mg/L)

Turbidity (NTU) 5 50 50 > 50 > 50 > 50

Total Suspended Solids 25 50 50 150 300 300

(TSS) (mg/L)

Conductivity (µS/cm) 1000 1000 1000-4000 1000-4000 4000 > 4000

2.7 Length-Weight Relationship

LWR is generally used to mathematically describe the relationship between the

length and weight of fish for interrelation purposes, and to estimate the weight for length of

individual fish or related fish species (Le Cren, 1951). The relationship can be a useful

information to calculate the allometric condition and biomass of a fish population (Cengiz,

2013). Nyanti et al. (2012) in a study in Lutong, Miri mentioned that LWR is important to

assess the fish stock in different locations in the world. In that study, only 3 out of 9 species

shows positive allometric growth and the reason for higher negative growth may be due to

the environment degradation and lack of food source. Another study by Muchlisin et al.

(2015) in Nagan and Sikundo, Indonesia, mentioned that the b value may be affected by the

fish behavior. Active fishes may have a lower b value compared to the passive ones due to

energy usage for movement and growth.

7

2.8 Feeding Habits

Fishes' feeding habits are determined by the physiology and morphology of their

digestive system (Brian-Eddy & Handy, 2012). This gives rise to different anatomy of

digestive tract in fishes (Shukla, 2009). According to Shukla (2009), carnivores have shorter

intestine length with strong acid secretion in their stomach compared to herbivores which

have longer intestine length. Brian-Eddy and Handy (2012) also mentioned that even fishes

from the same taxonomic family may have different habits. Fishes are normally categorized

as detritivores, herbivores, insectivores, carnivores or filter feeders, based on their food

preferences.

When a dam is introduced to a river, the natural food resource is altered rapidly

(Merona et al., 2003). This is due to terrestrial plant washed down from the upstream region.

Merona et al. (2013) also mentioned that the resources from plants like plant products and

invertebrates are the first to be exploited by the adapted species. Fishes that cannot adapt to

the new resources will either find a new ground for food or dies off.

According to Omondi et al. (2013), the study of feeding habits are important to

determine the diet of the fish and the trophic inter-relationships between species. Their

finding showed that Protopterus aethiopicus prefers molluscs, Clarias gariepinus prefers

fish, detritus and zooplanktons, and Oreochromis niloticus prefers algae, detritus and

zooplankton.

8

3.0 Materials & Methods

3.1 Study site

Murum Dam in Belaga, located upper region of Mumm River is the second

hydroelectric project in Sarawak after Bakun Dam. This dam has a height of 141 meter, a

catchment area of 2750 km2 and a reservoir size of 245 km2 (RECODA, 2013). Impoundment

of the dam started on 21s' September 2013 reached full supply level estimated to be around

540 m above sea level. The dam started operation in August 2014. Table 2 shows the

coordinates of every station recorded during the two trips. The coordinates of the stations

were taken using Global Positioning System (GPS) device (Garmin, GPS map 62s). Field

sampling were performed twice, from the 23`1 to 25th of August 2015 and 7th to 9th November

2015 at the downstream of Mumm Hydroelectric Powerhouse until the Murum River mouth.

Four stations were selected for both fish and water quality sampling covering a total of

almost 13 km of the river. Figure 1 shows the map of the study site.

Table 2. Coordinates of the four sampling stations.

Study Site Station Description Coordinates

Stretch of Murum 1 Murum Powerhouse N02°40' 12.2" E114°17' 34.7"

River below Murum 25 km from Murum Powerhouse N02°41'06.4" E114°14'27.9"

HEP 3 10 km from Murum N02°41'33.3" E114°11'41.6"

Powerhouse

4 Murum Rivermouth (13 km N02°42'23.9" E114'11'02.1"

from Murum Powerhouse)

9

0 km

I

?6 kni

J

S4

Danum River

Inundated Areas

Main River

Murum Powerhouse

® Dams

N

A

t

Inundated areas

Main River Murum River

Figure 1. The map of Murum River and sampling stations.

10

3.2 Water Quality

The water quality parameters that were recorded in situ were depth, temperature, pH,

turbidity, dissolved oxygen (DO), transparency, and conductivity. All the readings are taken

in triplicates. The water quality parameters that were measured ex situ included biochemical

oxygen demand for five days (BOD5), total suspended solids (TSS) and chlorophyll a (Chi-

a). The measurements were taken at every station in triplicates. Prior to the trip, all the plastic

water sample bottles were acid washed in 10% hydrochloric acid. All water samples were

taken at sub-surface (0.2 m).

3.2.1. Water Quality Parameters Measured In situ

For each station, water quality parameters measured in situ were taken using YSI

Multi-parameter Water Quality Sonde 6920 V2. Water transparency was measured using

Secchi disk and measuring tape.

3.2.2 Water Quality Parameters Measured Ex situ

3.2.2.1 Total Suspended Solids (TSS)

TSS analysis was done in three parts, which are pre-fieldtrip preparation, fieldtrip

sampling and post-fieldtrip analysis. Each filter paper (GF/C, 47 mm diameter, l µm pore

size) was soaked in distilled water, wrapped in aluminum foil and dried overnight in oven

(Felisa, Homo) under temperature of 103 - 105 °C until a constant weight was achieved.

The filter paper was then taken out from the oven and allowed to be cooled in a desiccator

to prevent weight fluctuation. The initial weight of filter papers was weighed using an

analytical balance (Acculab, ALC-210.4) and recorded on the wrapped aluminum foil.

The water filtration system was assembled and the prepared filter paper was placed,

using a forceps on to the glass inter-plate of the filter funnel, by placing the coarse side facing

.

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upwards. Next, water samples were mixed well by inverting the bottle and the water was

filled into the chamber by portions. A precaution step for filtration is not to pour large

volume of water sample into the funnel, instead start filtration with a smaller volume and

refill if the water can still pass through the filter paper. After the filtration process, the filter

paper was removed and folded back to the original aluminum foil. The volume of the filtered

water was recorded. All filter papers were dried overnight in oven at 103-105 °C. The filter

papers were then be taken out for cooling, and reweigh until constant weight was achieved.

The final reading of each filter paper was recorded. The calculation for TSS value in water

was based on APHA (1998) standard method. The formula used for calculation:

TSS (mg/L) = FF - Fi

V

Where: Fi = Initial weight of filter paper without sediment (mg)

FF = Final weight of filter paper with sediment (mg)

V= Volume of water sample used (L)

3.2.2.2 Biological Oxygen Demand in 5 days (BODs)

Water sample was collected using 300 ml BOD glass bottle. The initial DO value was

recorded using a DO meter. The bottle was filled completely without trapping any gas

bubbles. The stopper was inserted into the BOD bottle before wrapping it with aluminum

foil to avoid exposure to sunlight, preventing photosynthesis from taking place. The BOD

bottles were stored in a cooler box under room temperature (25°C) for 5 days. After 5 days,

DO readings was recorded again.

Calculation of BOD5 was done using APHA (1998) standard method. The formula is as

shown as below:

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BOD5 (mg/L) = Di -D5

Where: Di = Initial in-situ DO reading (mg/L)

D5 = DO reading after 5 days (mg/L)

3.2.2.3 Chlorophyll a

After sample collection, filtration was done as soon as possible using vacuum pump. The

filter paper (GF/C, 47 mm diameter, 0.7 µm pore size) was placed, the coarse side facing

upwards using a forceps. Volume of water filtered was filled cautiously to avoid the filter

paper from clogging. After filtration, the filter paper was wrapped with the original

aluminum foil. The wrapped filter paper was placed together with silica gel in a bottle to

absorb the water vapour and reduces the humidity in the bottle.

Each filter paper was then grinded thoroughly using pestle and mortar with a small

volume of 90% aqueous acetone solution. The completely crushed filter paper was

transferred into a centrifuge tubes. The total volume of solution was adjusted to 10 ml of 90

% aqueous acetone solution. The centrifuge tube was wrapped with aluminum foil, labelled,

and stored in the refrigerator for 4- 18 hours to ensure the complete extraction of chlorophyll

pigments. The solution was centrifuged for 10 minutes under 3000 rpm by using a centrifuge

(Hettich, type 1605 Universal 32). The supernatant layer was extracted and transferred into

a quartz cuvette (1 cm path length). The spectrophotometer (HACH Company, DR2800)

was switched on 30 minutes before the analysis process starts. Blank solution was prepared

by filling a cuvette with 90% aqueous acetone solution, and the spectrophotometer was zero-

ed to calibrate. The extinction of supernatant was measured at different wavelength of optical

density (750,664,647, and 630 nm). Each extinction was corrected for a small turbidity

blank by subtracting the absorption of 750 nm from 664,647 and 630 nm.

The calculation of Chlorophyll a was based on the APHA (1998) standard method:

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C. (gg/ml) = 11.85(E66a - E750) -1.54(E647 - E750) - 0.08(E630 - E750)

Where: C. = Concentration of Chl-a (gg/ml)

E750 = Absorption at 750nm wavelength

E664 = Absorption at 664nm wavelength

E647 = Absorption at 647nm wavelength

E630 = Absorption at 630nm wavelength

Calculation of the amount of Chl a per-unit volume is as below:

Chl a (mg/L) = (Ca)v

V

Where, Ca = Chlorophyll a concentration in µg/ml

v= volume of acetone in ml

V= volume of water filtered in L

3.3 Fish Samples Collection, Measurement and Preservation

Fish collection was carried out at all 4 stations along the downstream of Murum River

using gill net with different mesh sizes (5.08 cm, 7.92 cm, 10.16 cm, 12.7 cm, and 15.24 cm)

and 3 layer net with different mesh size (2.54 cm, 7.62 cm, and 17.78 cm). Nets were placed

in the morning and left overnight before retrieving it the next day. A ruler or fish measuring

board with scales was used to measure the total length and standard length of each fish. The

weight of the each fish was measured using analytical balance (SHIMADZU, ELB 300).

Photographs of selected species were taken. All the collected fishes were dissected to

measure the weight of stomach, liver and gonads. The stomach was preserved with 10 %

formalin for stomach content analysis.

3.4 Fish Identification

All fish samples were identified during field work or using taxonomic method

according to Tan (2006), Parenti and Lim (2005), Inger and Chin (2002), Kottelat et at.

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