Plankton is known as microscopic organisms that float and swim freely in pelagic currents and in other organic structures of H2O.
Plankton is made up of bantam workss which called phytoplankton and bantam animate beings called zooplankton. In add-on, zooplankton is known as pelagic being which can non keep their place in the H2O organic structures or against the H2O flow ( Idris, 1988 ) . There are many species of zooplankton can be found in estuarial country such as copepod, isopod, pelecypod and univalve larvae.Zooplankton can be divided into group such as holoplankton and meroplankton. Holoplankton is known as zooplankton that spend whole of their lifecycle in signifier of plankton while meroplankton is zooplankton that spend merely a portion of their lifecycle as plankton.
Meroplanktons are normally passing their life as plankton during eggs or larvae phase ( Idris, 1988 ) . In add-on, larvae of spineless being such as mollusk and Crustacea can be classified as meroplankton. Holoplankton in estuarine is normally dominated by copepode which can accommodate with Marine and fresh water environment.The zooplankton survey was carried out in Batang Kayan estuary, Lundu on 16th October 2010. Zooplankton communities are good known to be used as bio-indicator to find the status of H2O quality in Batang Kayan. Hence, the Batang Kayan can be considered as contaminated river. The survey is expected result is to document the zooplankton species and its relationship with H2O quality in Batang Kayan estuary.
There were few surveies of zooplankton that has been carried out in Sarawak such as Kuching Bay in 2005 by Jane Francesca, Batang Lupar by Suhartina Bt Arbe ( 2007 ) , Punang, Lawas and Limbang by Nur Atiqah Binti Mohamad Yusoff ( 2009 ) . Based on these survey, there 16 taxa found in Kuching Bay, 6 taxa in Batang Lupar and 10 taxa in Punang, Lawas and Limbang. There was no survey or information on zooplankton community at Batang Kayan River. The chief intents of this survey are:To enter the zooplankton community and its relation with the H2O quality.To find the species denseness, species diverseness, species evenness and species composing of zooplanktonTo bring forth the zooplankton community database for future biological monitoring in Batang Kayan River estuary.
2.1 Zooplankton composing
Plankton can be divided into 2 groups which are zooplankton and phytoplankton. Zooplanktons are besides known as the heterotrophic plankton.
The diverseness of aquatic being is increase towards the equator ( Idris, 1983 ) . Zooplankton can be divided into five different types of group which are microcrustacea, rotifers, cnidarians, comb jellies, segmented worms and mollusk ( Idris, 1988 ) . Some zooplankton species are known as one-celled animate beings such as Foraminifera. Crustecea is the most common of zooplankton found in Malayan fresh water ( Idris, 1983 ) . The figure of zooplankton in tropical increasing, while at the temperate will stay unchanged ( Idris, 1983 ) .
In Peninsula Malaysia, the most common zooplankton that can be found is Cladocera. Based on Idris survey, there are 6 households of common Cladocera found in Peninsula Malaysia. The six common households such as Family Sididae, Daphiniidae, Moinidae, Bosminidae, Macrothricidae and Family Chydoridae.Zooplankton that is normally 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 ( Volin, 2005 ) .
2 Adaptation of zooplankton
The distributions of zooplankton are normally based on the version of zooplankton species. Salinity is one of physio-chemical the factors that can impact the distribution of zooplankton. Zooplankton in estuarial country can be divided into 4 different constituent based on the zooplankton version. For illustration, stenohaline zooplankton such as Corycaeus sp. is normally found merely at the river oral cavity of estuarine ( Idris, 1988 ) . Euryhaline zooplankton such as Paracalanus sp. can be found farther into the mangrove country. Some species of zooplankton would non be able to digest with broad scope of salt alterations.
Zooplankton species such as Pseudodiaptomus sp. and Diaptomus sp. can merely be found in estuarine and fresh water severally.The zooplankton community is abundance every bit compared to fitoplankton community in the estuarine ( Idris, 1988 ) . This is due to the zooplankton community is dominated by the benthal invertebrate, fish and crustaceous larvae. The high population of zooplankton is recorded at Continental country ( Samolyk et al, 2003 ) . The Abundance of zooplankton will increased with increasing temperature, salt and chlorophyll a values ( Vieira et al, 2000 ) . Some species of zooplankton has ability to digest with broad scope of salt and pH alterations.
This species is normally found in the estuarine such as Acartia tonst ( 2ppt-36ppt ) , Acartia clause ( 14ppt-36ppt ) , Gammarus zaddachi zaddachi ( 1ppt-15ppt ) and Gamrnanus Locusta ( 25ppt-35ppt ) . ( Wilson, 1994 ) .Some species of copepods has the ability to accommodate polluted sites ( Bednarski & A ; Ramirez, 2004 ) .
2.3 Distribution and migration of zooplankton
Zooplankton community is of import in marine ecosystem nutrient concatenation. Zooplankton can be classified based on their size such as picoplankton ( & lt ; 2 Aµm ) , nanoplankton ( 2-20 Aµm ) , microplankton ( 20-200 Aµm ) , mesoplankton ( 0.2-20 millimeter ) , macroplankton ( & gt ; 200 millimeter ) .Zooplanktons are normally migrating into H2O organic structures during twenty-four hours clip and travel to the surface during dark clip ( Liu et al, 2003 ) .
This type of migration is known as vertically migration. However, the perpendicular distribution of zooplankton is influenced by physio-chemical parametric quantity of the H2O such as temperature, salt, dissolved O and food. Holocline is one of the factors that cause zooplankton change their perpendicular distribution and migration ( Lougee et al.
, 2002 ) . The chief ground that zooplankton migrate deep into the H2O organic structures during twenty-four hours clip is to avoid from marauder ( Lampert, 1989 ) . At lower temperature, the rate metamorphosis of zooplankton is lower than warm H2O ( Pia, 2007 ) .
Hence, zooplankton can salvage energy by feeding in the cool H2O ( Ellis, 2007 ) . In add-on, zooplankton will populate the home ground that rich beginning of food or nutrient. Zooplankton is more copiousness at the coastal country. This is due to the sum of food and chlorophyll a at coastal country is high which provides nutrient for zooplankton ( Rezai et al, 2000 ) .The entire figure of zooplankton species outside of the bay is higher than shoreline countries ( Webber M. , 2005 ) . Hence, shallow nature of inshore countries may impact low species Numberss as a consequence of absence of those species of common deep degrees zooplankton ( Webber M.
, 2005 ) . In the estuary, copiousness and biomass of mesozooplankton species is normally depending upon of alterations in salt. Hence, the copiousness of zooplankton is depending on the sum of fresh water input from the river ( Pia, 2007 ) .
High tides occur due to a assortment of physiological and physical procedures which can do the consequence has higher concentrations of larva and other mesozooplankton ( Pia, 2007 ) . Temperature and salt may play a function in the distribution of zooplankton in estuaries.
Factor influence the zooplankton distribution
Zooplankton distribution in the estuaries is influenced by physico-chemical parametric quantities of the H2O. In the estuaries, salt is varied due to the big input of saltwater during inundation and big input of fresh water during ebb tides. The H2O salt are besides varied at different deepness due to different in blending in the rivers ( Villate, 1997 ) .
The salt scope from 30 to 35 PSU is known as euhaline Waterss. Euhaline H2O is normally found at the oral cavity of the river where the fresh water meet the saltwater ( Pia, 2007 ) . The big input of saltwater during high tide will increase the marine zooplankton distribution and frailty versa during low tide.Temperature is besides play an of import function of the zooplankton distribution. The temperature is varied from the surface to the underside of the H2O. The temperature has the consequence on the zooplankton copiousness in multiple degrees ( Pia, 2007 ) . The growing of phytoplankton such as diatom is influenced by temperature. Diatom growing shows that positive correlated with the growing of zooplankton such as A.
tonsa.In add-on, zooplankton community in aquatic ecosystems is decreased by increased of eutrophication ( Lazzoro, 2006 ) . The physico-chemical parametric quantities and alimentary position of H2O organic structure is of import in regulating the production of plankton such as zooplankton constitute of import nutrient beginning of many aquatic being such as fishes ( Basu, Roy, & A ; Barik, 2010 ) .
Zooplankton as bio-indicator of the river
Bio-indicator is defined as an being that presence will indicates the quality of H2O environment status ( Wilson, 1994 ) . Zooplankton is one of the aquatic beings that could be used as a bio-indicator to find the status of the river. There are three constituent of estuarine system which can be used to measure the taint. They are H2O, deposit and being ( Wilson, 1994 ) . The changing of the H2O status will excite the being to accommodate to the alterations ( Dulic et al, 2006 ) .
If the organisms fail to accommodate with the alterations, they can non last in the estuary. Then, status of the H2O can be assessed by quantifying the grade of the being version ( Wilson, 1994 ) . Zooplankton responds rapidly with the alterations of H2O status such as pH and food. Therefore, zooplankton can be used as bio-indicators of the aquatic environment ( Dulic et al, 2006 ) . High sum of DO in H2O column is an indicant of healthy system in a H2O organic structure. Hence, this status of the H2O suited for aquatic being to populate.
Zooplankton composing in Sarawak
At least 58 households and 79 species of zooplankton is recorded ( Volin, 2007 ) .
The illustration of species founds are Oithona spp. , Acartia spp. , Longipedia spp. , Cyclops spp. and others. The survey in razor clam country was carried out before and after the razor clam season. Harmonizing to the survey, they were 14 species normally found before the razor clam season. The illustration of species found before razor clam season are Oithona spp.
, Pseudocalanus spp. , Paracalanus spp. and Ameira spp. The common taxa found during razor clam season at Asajaya Laut is nauphli copepods, Thespesiopsyllus spp. , spionid larvae and bivalve larvae. Foraminifera, bivalve larvae, spionid larvae and univalve larvae are the common species found at Pasir Puteh.
Based on the survey 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.
Material and method
3.1 Study Site
The survey site was chosen at the Batang Kayan River.
The field study was carried out at Batang Kayan estuarine from 15th to 19th October 2010. The trying site was divided into 5 Stationss. Coordinate of each station was recorded by utilizing Global Positioning System. Based on the observation, the flora from station 1 to post 3 was dominated by Nypa sp. while station 4 and 5 dominated by Rhizophora sp. and Avicennia spp.. The H2O of Batang Kayan River was turbid perchance due to the eroding occur at the upper watercourse of the river.
Land uncluttering for oil thenar plantation occurred at the upper portion of the river. In add-on, the river is besides affected by domestic waste wastewater produced by the occupant along the river. The trying site is shown in figure 1.
Degree centigrades: UsersUserDesktopsampling.jpgFigure 1: Sampling site ( Beginning: Google Earth, 2010 )
The zooplankton sampling was carried out during high tides which the entrance of saltwater to the river. The mesh size of plankton cyberspace used was 100 Aµm. Flow metre was placed at the oral cavity of the plankton cyberspace
3.2.1 Vertical distribution
For perpendicular distribution sampling, initial reading of the flow metre was recorded.
Then, the plankton cyberspace was dropped down into the H2O up to 3.35 metres ( 11ft ) . Following, plankton cyberspace was pulled with moderate velocity. The concluding reading of flow metre was recorded right after the plankton cyberspace was wholly pulled out from the H2O.
Then, the sample was put in the whirl-pak plastic bag and preserved with utilizing Lugol ‘s solution. Last, the sample was labeled harmonizing to each station. Two replicate of sample were collected at every station.
3.2.2 Horizontal distribution
For horizontal distribution sampling, initial reading of flow metre was recorded earlier towed. After that, plankton cyberspace was towed horizontally about 5 minute at every station. The clip was recorded precisely right after the plankton cyberspace was towed.
Then, plankton cyberspace was pulled out after 5 minute and the concluding reading of flow metre was recorded. The sample was put in whirl-pak plastic and preserved with utilizing Lugol ‘s solution. Two replicate of sample were collected at every station.
Physico-chemical parametric quantities
The H2O parametric quantity such as dissolved O ( DO ) , pH and temperature were recorded in situ by utilizing Eutech instrument ( Model PCD 650 ) while the turbidness was measured utilizing Eutech turbidness ( Model TN-100 ) and salt was measured utilizing Hand refractometer ( Model Atago S-10 ) . The reading of H2O parametric quantities were taken twice and the mean value were recorded. The chlorophyll-a information of the H2O were adapted from Asmyrita Husna ( 2010 )
4 Laboratory plants
The sample was sieved utilizing 100 Aµm mesh size screen to run out out the H2O sample. Any being that retained on the screen was transportation to specimen container which filled by distilled H2O.
2 Sub-sample, screening and numbering
After screening procedure, the sample was subsampled by utilizing 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 ) . The different form of zooplankton were separated and enumerated.
4.3 Species designation of Zooplankton
For designation procedure, a sample from each taxa is sorted out and placed on the prepared slide. Then, the sample was observed under compound microscope ( LEICA CME ) .
3.5 Data analysis
Speciess profusion ( D ) , species diverseness ( H ‘ ) , species evenness ( J ) , species denseness and species per centum ( % ) were calculated for each station utilizing the undermentioned equation: -Margalef index ( Margalef, 1958 )DfWhere S is the entire figure of species in a sample and N is the entire figure of single in a sample.Shannon-Weiner Index ( H ‘ ) ( Poole, 1974 )H’= -Pi=Where s is the figure of species found in a sample, N is the sum of single one species in a sample and N is entire figure of all species in the sample.Pielou Index ( Poole, 1974 )J’=Where H ‘ is species diverseness and S is the figure of species.Speciess denseness ( ind/l )Speciess density=Where N is the entire single one species in a sample and V is the volume of H2O ( L ) .Speciess per centum ( % )Speciess per centum ( % ) = X 100Where N is the figure of single species in a sample and N is the entire species in a sampleFlow metre expression: -Distance countDistance in metre ( m ) =Difference in count X Rotor changeless999999Where rotor invariable is 26,873Volume countVolume in three-dimensional metre ( M3 ) =3.14 X ( Net diameter ) 2Ten Distance4