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ZOOPLANKTON COMMUNITY. IN BATANG KAYAN ESTUARY, LUNDU, SARAWAK Harold Tinggang Ngau QL 123 Hl92 Bachelor of. Science with Honours 1011 (Aquatic Resource Science and Management) 2011

ZOOPLANKTON COMMUNITY.IN BATANG KAYAN ESTUARY, LUNDU, SARAWAK Community In Batang Kayan Estuary, Lundu... · Zooplankton Community in Batang Kayan Estuary, ... Batang Kayan, estuary

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ZOOPLANKTON COMMUNITY.IN BATANG KAYAN ESTUARY, LUNDU, SARAWAK

Harold Tinggang Ngau

QL 123 Hl92

Bachelor of. Science with Honours1011 (Aquatic Resource Science and Management)

2011

'usat Kbld..at Maldumat Akademik UNIVERSm MALAYSIA SARAWAK

Zooplankton Community in Batang Kayan Estuary,

Lundu Sarawak. P.KHIDMAT MAKLUMAT AKADIMIK

111111111 fiiilll1l1lllll 1000235824

Harold Tinggang Ngau

The Final Year Project is submitted in partial fulfilment of requirement for degree of

Bachelor of Science with Honours

Aquatic Resource Science and Management Programme

Department of Aquatic Science

Faculty Resource Science and Technology

University Malaysia Sarawak

2011

I

I'

ACKNOWLEDGEMENT

First of all, I would like to thanks GOD for His Blessing that I had managed to finish my final ., y·ear project on time. Secondly, I would like to thanks my supervisor, Prof. Dr. Shabdin Mohd

Long for giving me an opportunity and trusted me to conduct Zooplankton Community in

Batang Kayan, estuary Lundu Sarawak research. Besides that, I am very appreciating for his

guidance and support from the beginning until the end of my project. Next, I would like to

thank my beloved family who always support and trust me during my studies.

In addition, my grateful thanks also to both Mr. Richard Toh and Mr. Zaidi Ibrahim with both

contribution and hard work during my sampling. I am also thankful to my senior Mr. Chen

Cheng Ann and Ms. Nur Atiqah binti Mohamad Yusoff for their advice and encouragement

during my project. Last but not least I would like to thank my supportive friends Mr. Abang

Azizil Fansuri bin Abang Abdullah, Mr. Abdul Halim Karim, Ms. Asmyrita Husna binti

Ahmad and Ms. Siti Nur Sakinah Zainuddin. Thank You.

, \

I

DECLARATION

This thesis was based on my original research work at Batang Kayan estuarfLundu Sarawak.

Based on my knowledge and belief, there was no portion of the work referred to in dissertation

has been submitted in support of an application for another degree of qualification of this or

any other university or institution of higher learning.

HAROLD TINGGANG NGAU

Aquatic Resource Science and Management Programme

Faculty of Resource Science and Technology

\..Universiti Malaysia Sarawak.

II

Pusat Khidmat M.ldumat Akademik UNIVERSm MALAYSIA SARAWAK

Table of Contents

Acknowledgement................................................................ ............. .

IIDeclaration.......................................................................................

Table of Contents................................. ............... ... ........................ ... III

List of tables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... VI

List of figures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VII

Abstract........................................................................................... VIII

1.0 Introduction ..................................................................................

2.0 Literature Review. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .. . . . . . . . . . . . . . . . . .. 3

2.1 Zooplankton composition......... ... ......... ................................... ....... 3

2.2 Adaptation of zooplankton................................................ ...... .. ........ 4

2.3 Distribution and migration of zooplankton..................... ...................... 5

2.4 Factor influence the zooplankton distribution.................................... .... 6

2.5 Zooplankton as bio-indicator of the river........................... .................. 7

2.6 Zooplankton composition in Sarawak..................... ............................ 8

3.0 Materials and methods............... ...... ......... ........................ ...... ........ 9

3.1 Study Site................................................................................. 9

3.2 Zooplankton sampling.................................................................. 11

3.2.1 Vertical sampling ............................. :............................... .. 11 ,

3.2.2 Horizontal sampling ................. ~ .......................................... 11

3.3 Physico-chemical parameters. .................. ................... .... ............... 12

3.4 Laboratory works...... ............................. .......... .................. ..... ... 12

III

I

3.4.1 Sieving......................................................................... .... 12

3.4.2 Sub-sample, sorting and counting......................................... ..... 12

3.4.3 Species identification of zooplankton..................................':...... 13

3.5 Data analysis... ....................... ............................................... ... 13

4.0 Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16

4.1 Zooplankton........................................................................... ... 16

4.1.1 Vertical distribution............................................................. 16

4.1.1.1 Species composition... .................................... ...... ........... 16

4.1.1.2 Species density and percentage .......................................... . 19: I

4.1.2 Horizontal distribution ......................................................... . 24

4.1.2.1 Species composition........................................................ 24

4.1.2.2 Species density and percentage........................................... 26

4.1.2.3 Correlation between zooplankton community and physico­

chemical parameters of the water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

4.1.3 Species richness (D), Species diversity (H'), Species evenness (J)

and Species number........................................................ ... 33

4.2 Physico-chemical parameters of water................................................ . 35

5.0 Discussion............................................................................... ..... 41

5.1 Physico-chemical parameters of the water and zooplankton... ................... 41

5.2 Zooplankton composition .......................... :................ .................. 43

5.3 Correlation between zooplankton community and physico-chemical

parameters.............................. ................................................ 44

IV

I

1

6.0 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

7.0 References...................................................................................

8.0 Appendices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

47

48

52

"

v

LIST OF TABLES

Table Title Page

Table 1: Coordinate of each station................................ . .......................... 9

Table 2: Vertical distribution of zooplankton at 5 stations............................. ... 18

Table 3: Species density (ind/m3) and percentage (%) of each taxa ........ .............. 21

Table 4: Horizontal distribution of zooplankton at 5 stations............................. 25

Table 5: Species density (ind/m3) and percentage (%) of each taxa.............. . ...... 28

Table 6: Correlation between zooplankton community parameter and physico­

chemical parameters for horizontal distribution..... . ......... ...... ..... . ... .... 32

Table 7: Comparison of species richness (D), species diversity (H'), species

evenness (1) and speCIes number for vertical and horizontal

distribution............... . ....... . . . .......... ......................................... ............ 34

Table 8: Physico-chemical parameters for each station................................ .... 36

VI

LIST OF FIGURES

Figure Title Page

Figure 1 Sampling site at Batang Kayan estuarine (Source: Google Earth)...... .... 10

Figure 2 Comparison of species density at each station for vertical distribution.... 22

Figure 3 Comparison of zooplankton percentage at each station for vertical

distribution......................................................................... 23

Figure 4 Comparison of species density at each station for horizontal

distribution. . . . . ......... .......... ......................... ........................... ................. 29

Figure 5 Comparison of zooplankton percentage at each station for horizontal

distribution........ . ....................... . .............. . ......... .................. .... 30

Figure 6 Comparison of pH value at every station ...................................... . 37

Figure 7 Comparison of temperature value at every station ..................... . ..... . 37

Figure 8 Comparison of dissolved oxygen (DO) value at every station .. . ......... .. 38

Figure 9 Comparison of turbidity (NTU) value at every station ..... . ................ . 38

Figure 10: Comparison of current (ms· l) at every station .. . ............................. . 39

Figure 11: Comparison of salinity (PSU) at every station .................. . ....... . ... .. 39

Figure 12: Comparison of transparency (cm) at every station .............. . '" ........ . 40

;

VII

Zooplankton Community in Batang Kayan Estuary

Lundu, Sarawak

Harold Tinggang Ngau

Aquatic Resource Science and Management

Faculty of Resource Science and Technology

Universiti Malaysia Sarawak

ABSTRACT

The main purpose of this study was to record the zooplankton community and its relation with the water quality. A study on zooplankton community in Batang Kayan estuary Lundu, Sarawak area was carried out during high tide. The main purpose of this study was to record the zooplankton community and its relation with the water quality. As result, 13 taxa of zooplankton were identified. The zooplankton taxa were commonly found along the estuary was calanoida Copepoda, cyclopoida Copepoda, harpaticoida Copepoda, Gastropoda larvae and Bivalvia larvae. Calanoida Copepoda was dominant taxa and high percentage of distribution. The range of zooplankton percentage was between 0.23 % - 55.15 %. The distributions of zooplankton community at Batang Kayan estuary was influence by temperature, pH, transparency and current of the water. The data of zooplankton density, abundance and correlation with physico-chemical parameter can be used as a basic database for future research and biological programme planning.

Key words: zooplanktons, physico-chemical parameter, taxa

ABSTRAK

Tujuan utama kajian ini adalah untuk merekod data komuniti zooplankton dan hubungannya dengan faktor jizikokimia air. Kajian tentang komuniti zooplankton di muara Batang Kayan daerah Lundu Sarawak telah dilakukan semasa air pasang. Hasil daripada kajian ini, terdapat 13 taksa zooplankton yang telah dikenalpasti. Taksa zooplankton yang dijumpai di sepanjang muara ialah Copepoda calanoid, Copepoda cyclopoid, Copepoda harpaticoid, larva Gastropoda dan larva Bivalvia. Copepoda calanoid merupakan taksa dominan dan menpunyai taburan peratusan yang tinggi. Julat peratusan zooplankton adalah antara 0.23 %- 55.15 %. Taburan komuniti zooplankton di muara Batang Kayan dipengaruhi oleh suhu, pH, transparansi dan arus air. Data kepadatan dan kelimpahan zooplankton kelimpahan serta k<Jrelasinya dengan 1Jarameter jizikokimia air boleh digunakan sebagai data asas kepada kajian dan perancangan program pemantauan biologt pada masa akan datang.

Kata Kunci: zooplankton, parameter jizikokimia, taksa

VIII

1

1.0 Introduction

Plankton is known as microscopic organisms that float and swim freely in oceanic currents "

and in other bodies of water. Plankton is made up of tiny plants which called phytoplankton

and tiny animals called zooplankton. In addition, zooplankton is known as pelagic organism

which cannot maintain their position in the water bodies or against the water flow (ldris,

1988). There are many species of zooplankton that can be found in estuarine area such as

copepod, isopod, bivalve and gastropod larvae.

Zooplankton can be divided into group such as holoplankton and meroplankton. Holoplankton

is known as zooplankton that spend whole of their lifecycle in form of plankton while

meroplankton is zooplankton that spend only a part of their lifecycle as plankton.

Meroplanktons are usually spending their life as plankton during eggs or larvae stage (ldris,

1988). In addition, larvae of invertebrate organism such as mollusc and crustacean can be

classified as meroplankton. Holoplankton in estuarine is usually dominated by copepode

which can adapt with marine and freshwater environment.

Based on annual report of Natural Resource and Environmental Board, Batang Kayan River

was considered as poUuted river (NREB, 2004). Zooplankton communities are well known to

be used as bio-indicator to determine the conditi9n of water quality in Batang Kayan. Some

species of zooplanktop such as Copepoda (Cyclops) and Cladoceran (Daphnia) are able to ~

survive in acidic condition (Ferdous and Muktadir, 2009).

There were few studies of zooplankton that has been carried out in Sarawak such as Kuching ~

Bay by Jane (2005), Batang Lupar by Suhartina (2007), Punang, Lawas and Limbang by Nur

(2009). Based on these studies, there were 16 taxa found in Kuching Bay, 6 taxa in Batang

Lupar and 10 taxa in Punang, Lawas and Limbang. Meanwhile, there was no study or

information on zooplankton community at Batang Kayan River. The main purposes of this

study are:

i) to record the zooplankton community and its relation with the water quality.

ii) to determine the species density, species diversity, species evenness and

species composition of zooplankton

iii) to produce the zooplankton community database for future biological

monitoring in Batang Kayan River estuary.

,

2

1

2.0 Literature Review

2.1 Zooplankton composition

Plankton can be divided into 2 groups which are zooplankton and phytoplankton.

Zooplanktons are also known as the heterotrophic plankton. The diversity of aquatic

organism is increase towards the equator (Idris, 1983). Zooplankton can be divided into

five different types of group which are microcrustacea, rotifers, coelenterates, ctenophores,

annelids and mollusc (Idris, 1988). Some zooplankton species are known as single-celled

animals such as foraminifera. Crustecea is the most common of zooplankton found in

Malaysian freshwater and the number of zooplankton in tropical increasing, while at the

temperate will remain unchanged (Idris, 1983).

In Peninsula Malaysia, the most common zooplankton that can be found is Cladocera.

Acoording to Idris (1988), there are 6 families of common Cladocera found in Peninsula

Malaysia. The six common families such as Family Sididae, Oaphiniidae, Moinidae,

Bosminidae, Macrothricidae and Chydoridae.

Zooplankton that is usually found in Sarawak can be classified in the lowest taxa such as

Copepoda, Malacostraca, Ostracoda, Polychaeta, Appendicularia, Gastropoda, Bivalvia, , .' Thecostraca, Hydrozoa, Amphipoda, Chaetognatha, Foraminifera, Chordata and

Echinodermaia (Jane, 2005).

3

.I

2.2 Adaptation of zooplankton

The distributions of zooplankton are usually based on the adaptation of zooplankton

species. Salinity is one of physico-chemical the factors that can affect the distribution of

zooplankton. Zooplankton in estuarine area can be divided into 4 different component

based on the zooplankton adaptation. For example, stenohaline zooplankton such as

Corycaeus sp. is usually found only at the river mouth of estuarine (Idris, 1988).

Euryhaline zooplankton such as Paracalanus sp. can be found further into the mangrove

area. Some species of zooplankton would not be able to tolerate with wide range of salinity

changes. Zooplankton species such as Pseudodiaptomus sp. and Diaptomus sp. can only be

found in estuarine and freshwater respectively.

The zooplankton community is abundant as compared to phytoplankton community in the

estuarine (ldris, 1988). This is due to the zooplankton community is dominated by the

benthic invertebrate, fish and crustacean larvae. The high population of zooplankton is

recorded at continental area (Samolyk et al., 2003). The abundance of zooplankton will

increased with increasing temperature, salinity and chlorophyll a values (Jane, 2005).

Some species of zooplankton has ability to tolerate with wide range of salinity and pH

. changes. This spe~es is usually found in the estuarine such as Acartia tonsa (2 ppt - 36

ppt), Acartia clause (14 ppt - 36 ppt), Gammarus zaddachi zaddachi (1 ppt - 15 ppt) and

Gamrnanus locusta (25 ppt - 35 ppt). (Wilson, 1994). Some species of copepods has the

ability to adapt polluted sites (Bednarski & Ramirez, 2004).

4

Pusat Khidmat Maklumat Akademik lP~IV[It.'olm MALAYSIA SARAWAK

2.3 Distribution and migration of zooplankton I'

Zooplankton community is important in marine ecosystem food chain. Zooplankton can be

classified based on their size such as picoplankton « 2 11m), nanoplankton (2-20 11m),

microplankton (20~200 11m), mesoplankton (0.2-20 mm), macroplankton (> 200 mm).

Zooplanktons are usually migrating into water bodies during day time and move to the

surface during night time (Liu et at., 2003). This type of migration is known as vertically

migration. However, the vertical distribution of zooplankton is influenced by physio­

chemical parameter of the water such as temperature, salinity, dissolved oxygen (DO) and

nutrient. Holocline is one of the factors that cause zooplankton change their vertical

distribution and migration (Lougee et at., 2002). The main reason that zooplankton

migrate deep into the water bodies during day time is to avoid from predator (Lampert,

1989). At lower temperature, the rate metabolism of zooplankton is lower than warm water

(Pia, 2007). Hence, zooplankton can save energy by feeding in the cool water (Ellis,

2007). In addition, zooplankton will inhabit the habitat that rich source of nutrient or food.

Zooplankton is more abundance at the coastal area. This is due to the amount of nutrient

and chlorophyll a at coastal area is high which provides food for zooplankton (Rezai et at.,

QOOO). I

The total number of zooplankton species outside of the bay is higher than shoreline areas

(Webber, 2005). Hence, shallow nature of inshore areas may affect low species numbers as

a result of absence of those species of common deep levels zooplankton (Webber, 2005).

In the estuary, abundance and biomass of mesozooplankton species is usually depending

5

upon of changes in salinity. Hence, the abundance of zooplankton is depending on the

amount of freshwater input from the river (Pia, 2007) . High tides occur due to a variety of

physiological and physical processes which can cause the result has highe( concentrations

of larva and other meso zooplankton (Pia, 2007). Temperature and salinity may playa role

in the distribution of zooplankton in estuaries.

2.4 Factors influence the zooplankton distribution

Zooplankton distribution in the estuaries is influenced by physico-chemical parameters of

the water. In the estuaries, salinity is varied due to the large input of seawater during flood

and large input of freshwater during ebb tides. The water salinity is also varied at different

depth due to different in mixing in the rivers (Villate, 1997). The salinity range from 30 to

35 PPT is known as euhaline waters. Euhaline water is usually found at the mouth of the

river where the freshwater meet the seawater (Pia, 2007). The large input of seawater

during high tide will increase the marine zooplankton distribution and vice versa during

low tide.

Temperature is also play an important role of the zooplankton distribution. The

temperature is varied from the surface to the bottom of the water. The temperature has the

effect on the zooplankton abundance in multiple levels (Pia, 2007). The growth of

,phytoplankton such as diatom is influenced by temperature. Diatom growth shows that w

positive correlated with the growth of zooplankton such as Acartia tansa.

6

In addition, zooplankton community in aquatic ecosystems is decreased by increased of

eutrophication (Lazzoro, 2006). The physico-chemical parameters and nutrient status of

.. water body is important in governing the production of plankton such as zooplankton

constitute important food source of many aquatic organism such as fishes (Basu e/ ai.,

2010).

2.5 Zooplankton as bio-indicator of the river

Bio-indicator is defined as an organism that presence will indicates the quality of water

environment condition (Wilson, 1994). Zooplankton is one of the aquatic organisms that

could be used as a bio-indicator to determine the condition of the river. There are three

component of estuari_ne system which can be used to assess the contamination. They are

water, sediment and organism (Wilson, 1994). The changing of the water condition will

stimulate the organism to adapt to the changes (Dulic e/ al., 2006). If the organisms fail to

adapt with the changes, they cannot survive in the estuary. Then, condition of the water

can be assessed by quantifying the degree of the organism adaptation (Wilson, 1994).

Zooplankton responds quickly with the changes of water condition such as pH and

nutrient. Therefore, zooplankton can be used as bio-indicators of the aquatic environment

(Dulic e/ al., 2006). High amount of DO in water column is an indication of healthy

system in a water body. Hence, this condition of the water suitable for aquatic organism to oi

inhabit.

7

2.6 Zooplankton composition in Sarawak

At least 58 families and 79 species of zooplankton is recorded (Jane, 2005). The example

of species founds are Oithona spp., Acartia spp., Longipedia spp., Cyclops spp. and others.

The study in razor clam area was carried out before and after the razor clam season.

According to the study, they were 14 species commonly found before the razor clam

season. The example of species found before razor clam season are Oi/hona spp.,

Pseudocalanus spp., Paracalanus spp. and Ameira spp. The common taxa found during

razor clam season at Asajaya Laut is nauphli copepods, Thespesiopsyl/us spp., spionid

larvae and bivalve larvae. Foraminifera, Bivalvia larvae, spionid larvae and Gastropoda

larvae are the common species found at Pasir Puteh.

Based on the study done at Batang Lupar, there are 6 taxa were documented (Suhartina,

2007). Taxa of zooplankton that has been documented such as copepod, polycheate,

cumacea, branchyura, gastropoda and mysidacea.

8

3.0 Materials and methods

3.1 Study Site

The study was carried out at the Batang Kayan estuarine, Lundu Sarawak from 15th to 19th

October 2010. The sampling site was divided into 5 stations. Coordinate of each station

was recorded by using Global Positioning System. Based on the observation, the

vegetation from station 1 to station 3 was dominated by Nypa sp. while station 4 and 5

dominated by Rhizophora sp. and Avicennia spp.. The water of Batang Kayan River was

turbid possibly due to the erosion occur at the upper stream of the river. Land clearing for

oil palm plantation occurred at the upper part of the river. In addition, the river is also

affected by domestic waste effluent produced by the resident along the river. The sampling

site is shown in figure 1.

Table I: Coordinate of each station

Station Coordinate Brief description

NOlO 40.314

E 109° 51.470

2 N 01" 40.270

E 109° 52.419

3 NOl o 42.924

E 109° 52.084

4 N 01°40.683

E 109° 52.405 r'

5 NOl o 41.440

E 109° 55.581

Close to Lundu town and residential area. Less of

mangrove vegetation. Commonly dominated by Nypa sp.

Close to residential area. Less of mangrove vegetation.

Commonly dominated by Nypa sp.

Close to residential area. The changes of mangrove

vegetation from Nypa sp. to Rhizophora spp.

Less of residential area. Vegetation was dominated

byRhizophora spp and Avicennia spp .

At the riv~r mouth. The area was sheltered. Vegetation

was dominated by Rhizophora spp and Avicennia spp.

9

Figure I: Sampling site at Batang Kayan estuaries (Source: GoogJe earth, 20 I 0)

10

3.2 Zooplankton sampling

The zooplankton sampling was carried out during high tides due to obtained estuary ~

zooplankton. The mesh size of plankton net which has been used was 100 Ilm. Flow meter

was placed at the mouth of the plankton net. Two replicate of zooplankton was collected for

both distributions.

3.2.1 Vertical distribution

For vertical distribution sampling, initial reading of the flow meter was recorded.

Then, the plankton net was dropped down into the water up to 3.35 m (11 ft). Next,

plankton net was pulled with moderate speed. The final reading of flow meter was

recorded right after the plankton net was completely pulled out from the water. Then,

the sample was put in the Nasco whirl-pak plastic bag and preserved using Lugol's

solution. Lastly, the sample was labeled according to each station. Two rep~icate of .

sample were collected at every station (Goswami, 2004).

3.2.2 Horizontal distribution

For horizontal distribution sampling, initial reading of flow meter was recorded before

towed. After that, plankton net was towed horizontally for 5 minute at every station.

The time was recorded exactly right after the plankton net was towed. Then, plankton

net was pulled out after 5 minute and the final reading of flow meter was recorded. The

sample was put in Nesco whirl-pak plastic and preserved using Lugol's solution. Two

replicate of sample were collected at every station (Goswami, 2004).

11

3.3 Physico-chemical parameters

The water parameter such as dissolved oxygen (DO), pH and temperature were recorded in ".

situ by using Eutech instrument (Model PCD 650) while the turbidity was measured using

Eutech turbidity (Model TN-I 00) and salinity was measured using Hand refractometer (Model

Atago S-10). The reading of water quality parameters were taken triplicates and the average

value were recorded. Three replicate of water quality was recorded for the accurate reading.

3.4 Laboratory works

3.4.1 Sieving

The samples ware sieved using 100 !lm mesh size sieve to drain out the water sample.

Any organism that retained on the sieve was transfer to specimen container which

filled by distilled water.

3.4.2 Sub-sample, sorting and counting

After sieving process, the sample was subsampled using Folsom's Splitter. The

samples were divided into equal half. A half of sample was poured onto petri dish and

observed under Stereo Microscope (RaxVision Model: S 42904). The different shapes

ofzooplankton were separated and enumeratyd.

12

3.4.3 Species identification of zooplankton

For identification process, a sample from each taxa was sorted out and placed on the .. prepared slide. Then, the sample was observed under compound microscope (LEICA

CME). The guide books and journals for the zooplankton identification was 'Marine

Plankton' by NeweU (1979) , 'A guide to identification of Decapoda, Euphausiacea

and Mysidacea from the Southern Beaufort Sea' by Keast and Lawrence (1990) and

'Zooplankton Identification Guide' by Yamaguchi and Bell (2007).

3.5 Data analysis

i) Species richness (D) was to measure of the number of species found in a

sample. Species richness was calculated by using Margalef index (Margalef,

1958).

Marga]ef index (Margalef, 195~).

(S-1)Dr=-­

Ln N

Where, S = total number of species in a sample.

N = total number of individual in a sample.

13

ii) Shannon-Weiner Index (H') to calculate the species diversity in certain area.

Shannon-Weiner Index (H') (Poole, 1974)

H'= -Lf=l Pi logz Pi

n Pi=­

N

Where s= number of species found in a sample,

n= total of individual one species in a sample

N= total number of all species in the sample.

iii) Species evenness (1) was to determine the species dominance in a certain area.

Species evenness was calculateo by using Pielou Index (Pielou, 1975)

Pielou Index (Pielou, 1975)

HI! 1'---­

Ln S

•Where H'= species diversity

S = the number of, species

14