ANALYSIS OF SUITABILITY OF MANDEII BAY
FOR CULTURING TIGER GROWER
(E.
fuscoguitatus)
IN FLOATING NETS CAGE, PESISIR SELATAN REGENCY,
WEST SUMATRA PROVINCE
By:
ZAITUL IIGILAS
C251040354
STUDY PROGRAM
MARINE AND COASTAL RESOURCES MANAGEMENT
POSTGRADUATE SCHOOL
BOGOR AGRIC&TLTmE UfVlVERSITY
-ABSTRACT
Zaitul Ikhlas. Analysis of Suitability of Mandeh Bay for Culturing Tiger Grouper (Epirreplrelus fuscoguttatrrs) in Floating Nets Cage, Pesisir Selatan Regency, West Sumatra Province. Advisors: Ismudi Muchsin, Zairion, and Moharnmad Mukl~lis Kamal.
Biophysical suitability of seawater is one of highly important indicators that should be considered for culturing tiger grouper (Epinephelus j%scogutl~lzrs). Unsuitable site for the culture can influenced on low grouper production and on degradation of coastal euviromtlnent. Objectives of this research are (1) to analyze biophysical characteristic of water of Mandeh Bay, and (2) to evaluate biophysical suitability of water for culturing the grouper. This research is conducted &om April to May 2006 in Mandeh Bay, Pesisir Selatan Regency, West Sumatra Province. Environment data that needed are depth, temperature, salinity, transparency, turbidity, TSS, DO, BOD5, chlorophyll-a, pH, tide, wave, and current. For analyzing biophysical characteristic of water of Mandeh Bay is used Pri~lcipal Component Analysis (PCA); and for evaluating biophysical suitability of water is used Geogra$ic Information System (GIs) method. The results show the Mandeh Bay is characterized by high values of parameters of temperature, TSS, turbidity and pH; and low value of parameter of depth. These parameters are highly influenced by existences of environmental characteristics of the bay such as mangrove, seagrass bed, river runoff, climate, settiement, and fish landing. Generally biophys~cal characteristics of water of Mandeh Bay are suitable for growth of the tiger grouper
(Ep~nephelzrsfir~cogultatus) in the FNC, except for the water depth. The potential waters for the culture are in surrounding Cubadak Island, Mandeh Village and Simpang Carocok Village except the water in the Southwest of Simpang Carocok Village.
Title : Analysis of Suitability of Mandeh Bay for Culturing Tiger Grouper (E. $rscogztttatzls) in Floating Nets Cage, Pesisir Selatan Regency, West Sumatra Province
Name : Zaitul Ikhlas
Registration Number : C25 1040354
Approved by Advisory Board,
Prof. Dr. Ir. Ismudi Muchsin Supervisor
Ir. Zairion. MSC. Dr. Ir. M. Mukhlis Kamal. M.Sc.
Co-supervisor Co-supervisor
Acknowledged by: -
Head of Study Program,
BIOGRAPHY
Autho- was born on August 7, 1967 in ~adang, West Sumatra Province as first children of five brothers from Abdul Rahman and Yuslaini. In 1992, Author graduated &om Department of Fishery Resources Utilization, Faculty of Fisheries and Marine Sciences, Bogor Agriculture University. In 2004, Author stodied,.at Marine and Coastal Resources Management, Postgraduate School of Bogor Agiculture liniversity, sponsored by 'the Project of Marine and Coastal Resources Management that managed by "Departemen Kelautan dan Perilcanan".
PREFACE
Thank to Allah SWT for God's mercy that given to Author who has already finished writing this :hesis. Title of this thesis is "Analysis of Suitability of Mandeh Bay for Culturing Tiger Groupa' (Epinephelusfuscogulra~us) in Floating Nets Cage, Pesisir Selatan Regency, West Sxnatra Province" that has been canied ont from April wtil May 2006.
Utilizations of marine and coastal areas for culturing the grouper especially in water of bay have developed in some regions in Indonesia such as Lampung, Bali, Sulawesi, and also West Sumatra Province. The utilization of the water bay for the grouper culture should be done carefully because the areas are susceptible toward various negative iinpacts of$evelopmeut activities. Those negative uupacts are such as environmental degradation, overfishing of marine biota, interest conflict, low production of cultured fish, etc. Activity of the gouper culture in Floating Nets Cage (FNC) beside it produc-s positive impacts on community (i.e. increasing incc,ine), it aiso produces tiagative unpacts on c~lviro~unent, marine biota and also'bil community (i.e. degradations, pollutions and interest conflicts). Therefore, developing the culture should been planed comprehensively. The most importance factors that must be considered in tlie plan are selection and determination of suitable water for culturing the grouper. In this research it has been camed out analysis to~vard biophysical characteristics of water of Mandeh Bay, and suitability of the water for culturing the grouper. Biophysical parameters of water that are analyzed encompassing depth, wind and current velocity, wave, temperature, salinity, Dissolved Oxygen (DO), BODS, transparency, turbidity, TSS, and pH.
in co~ectioll with it iras already finished this thesis, Author would like to thank to:
1. Bapak Prof. Dr. Ir. Ismudi Muclisin, Bapak Ir. Zairion, M.Sc., and Bapak Dr. Ir. Mohammad Mukhlis Kamal, M.Sc., for your helps in guiding Author to finish this thesis.
3. Bapak Drs. H. Nasrul Abit (a Regent of Pesisir Selatan Regency), Bapak Drs. Syafiizal Ucok (a Vice of Regent of Pesisir Selatan Regency), Bapak Drs. H. Adril (a Secretary of Region of Pesisir Selatan Regency) and Bapak Alirman
S o ~ y , A.Md, SH., M.Hurn (a Chief of Coininunity Representative Council) for your supports to Author both moral and material during this study.
4. , Author's Parents and brothers who always pray Author's success in this study.
Author special thanks to Author's wife, Lusi, for her love and support, and also to Author's cl~ildrex, Maulana Hndzaifah Luza, Mullammad Habibullah Luza, and Fatunall Azzallra Luza, for their patience waiting Author's study finished,
5. Mas Sigit, Mbak Wahyu, Mbak Retno and Bu Mala (Bappeda of West Stunam Province) for your supports and helps to Author carried out observation in study area.
6 . Finally, Author's classmates; Zainal, New, Efiizal, Saptoyo, Enen, Edo, Machmud, Norma, Yesi, C o b , and Kus, and also friends f?om DKP; Wirman,
Aan, Emil, Firdaits, and Rofy tliank for your support, attention and kindness
d c h g both we were iii Den=& and Bogor.
Bogor, September 2006
STATEMENT LETTER
I state that this thesis, where its title is "Analysis of Suitability of Mandeh Bay
CONTENTS
Page
...
I'REFACE
. . .
....
.
.
...
CON1 15N 1 5
...
LIST O F TABLESI . IST O F FIGURES
...
LIS'I' O F APPENDIXES... Background
I'onnuli~~io~i of1'1~ol)lenrs ...
.
.
...
Objecclrves of Research
Benefits of Research . . . ... Scopes of Act~vit~es
...
Boundary of study areas
...
Activities ...
LlTERATURE RIVIEW
Characteristics of Marine and Coastal Areas ...
Statue of Manculture by Floating Nets Cage (FNC) ... Floating Nets Cage (FNC) ... Tiger Grouper (Epinephelus jiiscogz~ttatz~s) ... Characteristics of Biophysical of Seawater
...
Parameter of biology ...
...
Parameter of physical
Parameter of chemical ... Suitability of Water for Mariculture
...
Suitable concept for ~nariculture
...
Comparison concept of parameter for suitability
...
Suitability parameters of water for grouper culture...
Weighting suitability class of water
...
Geography Infonnation System (GIs) for Developing Fishery Culture
...
RESEP-RCH METHOD
...
Study Area and Sarnpling Psriod ... ... Data Collection
Sampling procedure ... Supporting data ... Data Analysis ...
Analysis of biophysical characteristics of waters ... Analysis of biophysical suitability of water (potency) ...
...
. i'I<Ol;ll. lC O F MANDEII BAY COASTAL AREAS
... Cliinate
...
nathvmctrv
... .ride
...
Current
...
...
Wave
.
.
....
.
...
Marine and Coastal Resources Conditions
...
Mangrove forest
...
Coral reef
...
Seagrass bed and seaweed
.
.
...
Socio-economic Condlhons...
Comnunity . .
...
L~velihood
.
.
...
...
Facihty
.
.
.
Utilization of Coastal Areas Resources of the Mandeh Bay
...
RESULT AND DISCUSSION
...
... Results
Biophysical Characteristics of Water of Mandeh Bay ... Biophysical Suitability of Warer for Culturing Tiger Grouper
(l<p:~i~p/reh~.~.fi~.~co~'ti/~o~z~.s) in Floating Nets Cage (FNC)
...
...
Discussions
Biophysical Characteristics of Water of Mandeh Bay
...
Biopl~ysical Suilability of Water for Culfurirlg Tiger Groupcr
(Epinephelzrs~fir.rco~~~~~a/us) in Floating Nets Cage (FNC) ...
...
CONCLUSIONS AND RECOMMENDATIONREFERENCES
...
...APPENDIXES
LIST TABLES
Page
Suit;~bility of Water for EAaricultr~re based on Values ofTSS
...
13Biophysical Parameters of Water to Culture Tiger Grouper
...
(l<pi17c~~1el7rs/irsc0~~1lla/u.r) 16
Primary Data ... 21
...
Secondaly Data 21
Interval of Final Values and Suitability Classification of Waters ... 27
Percentage of Commul~ities Education Level of the Mandeh Bay Region 37
Kinds of Livelihood in the Mandeh Bay Region
...
38Support Facilities of Social and Economic Activities of Local
...
Co~n~n~rr~ities of the Mandeh Bay Region 38
Kinds of and Nurnber of Fishing Gear in the Mandeh Bay
...
39Suitability of Water of Each Sub Stations based on Biophysical
...
LIST
FIGURES
...
Floating Nets Cage in Mandeh Bay
Tiger Grouper (Epit~epi~elzrsj~scoguttatus) in Floating Nets Cage (FNC) ... in Water uf Mandeh Bay
...
Comparison Process of Parameter for Suitability
...
A Map of Mandeh Bay Region and Study Area
Flowchart for Determining Potential Waters to Culture Tiger Grouper
(I~pinephelus~scoguttatus) in Floating Nets Cage (FNC)
...
Flowchart of Process Interpolating Point Data in Model
...
Flowchart of Overlay for All Biophysical Parameters
...
Bathymetry of the Mandeh Bay Water
...
A Map of Current Velocity Distribution of Mandeh Bay Water
...
A M ; I ~ of Wave I-leights Distribution of Mandeh Buy Water
...
Avcragc Valucs of Water Depth on Sub Slations
...
Avcrage Values of Salinity on Sub Stations
...
Average Values of Chlorophyll-a on Sub Stations
...
Avwagc Values ofTransparency on Sub Stations ...
... hvcragc Valucs ofTSS on Sub Stations
...
Average Values of Temperature on Sub Stations
...
Average Values of DO on Sub Stations :
...
Average Values of Turbidity on Sub Stations ...
Average Values of BODS on Sub Stations
...
Average Values of pH on Sub Stations
...
A Graphic of Distributions of Biophysical Parameters on Principal
...
INTRODUCTION
Mandeh Bay region is located in the Pesisir Selatan Regency of West Sumatra 1'1-ovince comprised of 9 small islands encompassing marine and coastal areas of approxi~nately 2673.1 1 Ha. In this area a variety of ecosystem characterized to coastal waters, inangrove, coral reefs, seagwss bed and seaweeds ecosystem can be found. Marine small islands and these natural resources, therefore it is considered that the coastal area of the Mandeh Bay has a great potency of marine and coastal resources, which is an importance aspect for conununity economic activities.
One of economic activity to be developed in the cohstal area is mariculture. The maricultiire might be best to developed as an alternative livelihood in order to increase the income and welfare of local community. There are several reasons of the i~nportance to develop accordingly the inariculture (1) production of capture fisheries in Indonesian water, including West Sumatra Province, are decreasing, on tlie other hand the lnarket demands are increasing (Rusman, 2003), and (2) Mandeh Bay with area of approximatel!! 2673.1 1 Ha provide a pro~nising site for mariculture development especially by mean of Floating Nets Cage (FNC). According to Rusman (2003), (1) this culture of grouper is very efficient in using area (water) as location of the culture where its productivity level is higher, (2) business unit could be agreed with cost, (3) easy to control, and (4) efficient io using times and manpower.
Based on the above co~lsiderations the attempt to develop the grouper culture may be resulted a significant impact for increasing fishery productions, local com~nunity income as well as to fill tlie need of highly protein content nutrition. Considering that coastal water is very susceptible against various impacts that resulted !?om eco~iolnic activities and changing environment conditions, developing b~ouper culture activity in the bay should be planned comprehensively and accurately so that this grouper culture could be sustainably managed.
For dcvclopir~g the groupcr c~ilturc i n the FNC, two of importance aclivilics that need to be planned are selecting and determining a location of the culture, as tl~esc iwo activities arc Ulc key factors for the success of grouper culture. An
2
fhilure in production process. Based on a Presidential Decree No. 2311982 about dcvclopi~~g maricult~ue in Indonesia water, selecti~~g and determining part of waters that would be became as location of mariculhkre, the location should fulfill requirements of technique, and considering importance of other sectors. Then, based on a n . Agriculture Minister Decree No. 473/Kpts/Um/7;1982 abont i~nple~nentation guideline of tlie Presidential Decree, the technique requirements one of them is waters suitability biophysically fcr necessity of culture.
Referred on the Presidential Decree No. 2311982 and its implementation guideline, it is importance to know the characteristic of selected sites biophysically in order to find a suitable location for developing the grouper culture. Accordingly, for supporting the plan of development, data and information of above aspects should be analyzed to get suitable location for culturing the grouper.
Formulation of Problems
. ~
By a Decree of the Govenunent of Pesisir Selatan Regency No.5i2001, March 31. 2001, regarding Marine and Fishery Sector, the coastal area of Mandeh Bay is part of Development Area-1V (DA-IV). This is,based on a cousideratio~i that this area is highly potencies in resources that cotild be utilized to develop various com~nunity economic activities, including mariculture.
Out of r~~itr-icr~lturc i~ctivitics that have been developed by local goveniincnl is tiger grouper (/<pit~eplie/zrsjrscogut~a/us) culture using Floating Nets Cage (FNC) tccl~~~iquc. 'I'lo biicligrou~~d of dcvcloping Ulc culturc activity arc (1) thc bay has potencies to develop the activity; (2) the grouper is the region's superior commodity
i n sub sector ofcu!ture fishery because of its high economic value in the market; aid (3) it is hoped that this activity could increase the economic development in region. In 2003 and 2004, the local government has initiated to develop an intensive the grolipcr culture up to I0 units FNC (30 cages) located in water of Mruideh Village. In 2006, the FNC will be increased to 20 units FNC (60 cages) at the same location, fi~nded by tlie Marine and Coastal Resources Management Project (MCRMP) of 2006 (DKP- Pesisir Selatan Regency, 2006).
factors may be insufficient to be used in site determination for the mariculture. This could give impact to (1) lower growth rate of the grouper because characteristics of the part of waters are unsuitable yet with requirements of water characteristics for growth tlie grouper, and (2) the local government has difficulties to develop the appropriate suitable culttlre's location due to insufficient information of biophysical parameter of water.
According to "DKP of Pesisir Selatan Regency" (2006) tots1 of grouper production in 2004 and 2005, were approximately 288 kg (2 units with 6 cages) in
1-004, ; t i ~ t l 1 152 kg (8 units wt11 18 cages) in 2005, where average of their growth rate approximately 54 gram1individuaVmonth. This growth rate is lower than growtll rate of grouper that has been ever canied out by "Balai Budidaya Laut Lainpung" iii 1985 in the five provinces (Riau, East Java, Bali, North Sulawesi, and Ainbon). 111 these provinces, tlie growth rate of tiger grouper (fipinephelus
,/i~.sco~~r//atu.~ was 75 - 100 gram/individuaVmonth. However, this growth rate could still be increased again using good i,ianagement especially for water quality, beside for production factors such as feeds, and szeds (Adji e: G!., 1998).
'fhe lower growtli rate of grouper in the bay is presumed caused by water condition is unsuitable for growing the grouper. The existence of water characteristic is iiifluenced by various community economic activities surrounding areas where these activities could result negative impacts for the waters. It has long been known that the Mandeh Bay is not only utilized for the grouper culture but also utilized other activities such as capture fisheries (lift nets), transportation, and coastal tourism (Cubadak Island). It is predicted, that highest activities level is not only eliciting conflict interest among users or stakeholders, and decreasing water characteristics quality, but also degradation of resources ecosystem.
Based on the above descriptions, problems in this research are identified as follow ( I ) biophysical cl~aracteristics ofthe bay waters are not well knowti, and (2)
biophysical suitability of the bay water is not known yet.
Objectives of Research
4
Benefits of Researcl~
To provide information at which part of the ~ a n d e h Bay that is the develop need of the gouper culture with Floating Nets Cage (FNC) technique.
Scopes of Activities
Boundary of study area
Study area of "Analysis of Suitability of Mandeh Bay for Developing Grouper Culture in Floating Nets Cage (FNC) in Pesisir Selatan Regency, West Sumatm Province" is in water of Mandeh Bay; they are water surrounding Mandell Village, and Si~npang Carocok Village. This area is in Sub District of Koto XI Tarusan, Pesisir Selatan Regency-West Sumatra Province.
Activities
The activities that were carried out are:
I ) Alialysis of biopliysical characteristics of water based on the parameters of ch!orophyll-a, pH, sali.lity, Dissolved Oxygen, Biochemical Oxygen DclnandBODs), depth, wind, current, wave, temperature, transparency, turbidity, and Total Suspecded SolidITSS).
LITERATURES RIVIEW
Characteristics of Marine and Coastal Areas
The coastal zone includes both the area of larid subject to marine influences illid tlic ilic:~ 01'111~ sea SIII),~CCI to la~id iiilluc~lccs. This coastal zone corlsists of tllrcc main co~iiporients: tlie sea, the beacli, and tlie land behind tlie beach. 'rlie sea, or oiTslioic ;trc;i. cstcrids fi-on1 tlic low watcr mark seaward. This area covcrs the sh;illow marine habilats of the coast, sucli as tlie seagrass bed, and the coral rccfs among otliers. The beach zone extends from the low water mark to the seaward edge of (lie coastal vegetation. Tlie last cotnporient of tlie coastal zone is the adjoining coastal land. This zone extends landward for some distance from the end of tlie beacli (UNEP, 2001 ).
The coastal zolie is a highly sensitive zone, where a number of ecosystems exist ill a state of balance. This zone is affected not only by local conditions but also
by events and conditions long distances away. Pressures from liunan habitation and econo~nic developmelit arc common in the coastal areas of the world. The management of sucli area is of necessity an integrated and multidisciplinary effort (Clark, 1988; Cambers, 1992; and Dahuri eta/., 2001).
Statues of Mariculture by Floating Nets Cage (FNC)
Based on Law No. 3212004 regarding the local government, one of economic activities that need to be supported its development in coastal areas is maricultore. Referring to existences of tlie areas, they have larger opporlunities to be developed its ~rtiliza~io~i. Accordiiig to Soeprapto it? llusman (2003) Indonesia's coastal water
has potencies of areas for developing mariculture approximately 1.9 millions ha, where about 369.500 ha of them is suitable areas (potencies) for culhuing finfish ( 1 1 1 c l 1 1 i . 1 0 0 ) . Thi~s. tlic l!ido~icsia's waters have large potency of mrtriculti~re (grouper and seaweed).
6 Therefore, for developing the mariculture activities tlie envirorunent factors should be assessed so that the culture activity can go continuously and rationally.
Coastal areas as locations of rnariculture (Floating Nets CagdFNC) have comparative superiorities cornpared with other culture activities in upland, some of them are (I) this activity is efficient enough in using areas and its productivity level IS higher, (2) can be controlled easily, and (3) efficient in using times and manpower (Rusman, 2003).
Floating Nets Cage (PNC)
Floating Nets Cage (FNC) as "dwelling" for grouper should be constructed on both sides of strength and size. Construction strenbdi of the FNC becomes very importance thing to be considered because existences of it in water areinfluenced by cu~rent and wave characteristics. Then, size of it (long, width, and depth) also is considered because the groupers need suitable spaces for their growth. If they are growll~ inlo small FNC relatively with high population density, they have decrease circulation of dissolved oxygen in the water, and also can stimulate cannibalism lcvcl i1111011g I I l ~ l 1 1 .
Sizes of tlie FNC that IIZS been used by Adji et al. (1998) to culture of grouper
i n 4 provinces ~ I I C 4111 x 3111 x 2.5111 [Riau), 3.5m x 3.5m x 2m (East Java) 2111 x 2111 X 21n (Bali), and 21n x 2111 x 2111 (North Sulawesi), by density of cultivation 10
ckol-/n~' (avcrayc 150 griu~l/individu;~l). Tllcrl, size of FNC in Mandeh Bay is 4n1 * 41n x 2.5111 by density of cultivation 5 ekor/m3 (average 100 gramlindividual) (DKP ol'l'esisir Selatan Regency, 2006). Fig. 1 sl~ows one of FNC constructio~is in water of Mandcll Ray, Pesisir Selatan Regency of West Sumatra Province.
Tiger grouper (Epiriep~~el~is~iscogi~tt~~tii.~)
Groupers are classified into subfamily Epinephelinae from family Serranidae.
Regency, 2006)
According to Plillip and Randall (1993), habitat of the grouper is bottom of water that has coral reefs and rocky on depth less than 60 meter. Its juveniles gro~v in sea-grass areas. Generally, its inorphologies are (1) body height is 2.6 to 2.9 times of body length; (2) head length is 2.3 to 2.5 times of body length; (3) body color is yellowish brown, by 5 vertically parallel lines; and (4) head, body, and fin covered by brown spots. The grouper's classifications are as follow (Phillip and Randall, 1993):
Class Sub class Order Division Family Sub family Genera Species
Chondrichthyes Elasmobranchii Percornnorphi Perciformes Serranidae Epinephelinae
Epineplielzrs
Epinephelusfiscogtrttalz~s
[image:18.536.46.468.20.763.2]Fig. 2. Tiger Grouper (Epinephelz~sJi~scog~itfaft~s) in Floating Nets Cage (FNC) in Water of Mandeh Bay (Source: DKP of Pesisir Selatan Regency, 2006)
Characteristics of Biophysical of Seawater
Parameter of biology
a. Chlorophyll-a
Chlorophyll-a is a pigment inside pl~ytoplankton, wbicli has function as mediator in photosynthesis. Therefore, content of chlorophyll-a becomes an indicator to know abundance of phytoplankton that indicated a primary production of water (Daniel and Schindler, 2004). Ideally the content of chlorophyll-a of seawater to culture the grouper is over 20 &liter (Hasyim, 2003).
Primary production is as amount of organic compound produced by autotrophy organism; that is organism that has capability to produce the organic compound from inorganic compound. Primary productivity frequently limited by the availability of nutrients in seawater. It is explained in g ~ / m ~ / ~ e a r (Reynolds, 1984; Parson, Takaslu, and Hargrave, 1984; Osbome, 2000; Beardall, Young, and Robertsl, 2001; and Sverdmp, Duxbury, and Duxbury, 2006). Classic methods to determine the primary productivity are a method of "bright-dark bottle" and a method
'k
(Nybakken, 1997). According to LPPM-IPB (2004) a primary productivity is a result of photosynthesis process. [image:19.539.80.463.43.283.2]conipound influenced on reproduction of fish (Nontji and Ilaliude in Wardjan, 2005). Important organic colnpounds that needed by phytoplankton are nitrogen and pliospl~atc (I';trson, Takaslli, and 1-largrave, 1984; Osbome, 2000; and Sverdmp el a/., 2006).
OIIC of' ~ i i [ r o g c ~ ~ - i ~ i ~ ) r g ; ~ i ~ i c !yl~cs (N-i~~orgar~ic) tI1r11 v e ~ y si11)~)orIing lire ol'
organism in the sea especially to pllytoplanktoll is nitrate (NO,-N) (Ueda el nl., 2000). /\ccordi~ig lo Ucdit rt irl. (2000) atid Ell'c~idi (2003) ~iilri~le (NO,-N) is important type of nit~ogen in natural water and it is important nutrient for growing algac artd plant. At r~acural wzter co~~cei~tratiori ol'nilrogen is less Ilia11 or equal will1 0.1 mgliter (< 0.1 nidliter). If the concentration exceed more than 5 mdliter, the water has been polluted of antllropogenic nitrogen came from human activities and feces of anima1,'and if its concentration is more
than
0.2 mglliter, the water has been ezrlroficn~ion and then can stirnulate growing mass of algae and water plants (blooming).Phosplior compound is type of phosphate that can be utilized by plant for growth (Dugan in Effendi, 2003).
Aii
existence of phosphate compound i~ water can be limiting factor for growing phytoplankton because this compound is very essential for high level plants and algae (Eppley and Peterson, 1979; and Effendi, 2003). Jones and Bacllrlla~l i ~ i Effendi (2003) mentioned that there is positivecorrelation between phosphor total compound and clilorophyll~~a. In the lnariculture co~icc~icl'atiol~ of pliospl~ate ideally is 0.02 1-0.10 pprn (Anggoro in Rustna~~, 2003).
Parameter of physical
a. Depth
10 b. Current, wave and tide
According to Hasyim (2003), current, wind and wave have influence on the FNC gouper culture. Highly current velocity can damage cage and nets, move position of nets, and also influence on operating of the FNC. Design and co~~stn~crion of fllc cage shouid fit i n will1 the current velocity in areas. On the contraty, sinallest current velocity can increase the number of biofouling organism at the body of nets. The hicfiirlifig organism can hamper the circulation of water in the FNC (Rusman, 2003).
The wind influences on the wave. Tlie bigger wind velocity in surface of water, the bigger wave will occur. On the contrary, the smaller wind velocity, tlie s~l~allcl. wave will occur. Sl~iipt. ot'wave caused by wind iiicli~~ed il~defi~lite, depend on velocity and direction of wind and also contour of the bottom of this sea. Height of wave will decrease along with decreasing depth of water when it came to beach (Sverdrup el a/.. 2006).
The bays are suitable location for culturing the grouper in the FNC. Ideally cllrrcrlt velocity and wave height for culturing the tiger grouper (Epinephelus
ji~scogp~la/us~ are 10.00-30.00 cmfsec (Sudjiharno, 2001; and I-Iasyim, 2003) and
0.1 0-0.50 m respectively (Ahmad el 01. 1991; ~udjihamo, 2001; and Hasyim, 2003). Tidal is process of up and down of sea surface gadually that influenced by the position of the moon, the sun and the earth. The tidal value depends on position of the moon andthe sun toward the eartli. Generally, there are 3 types of tide, which are diurnal, semi diurnal, and quartemal. These types depend on changing o f the water depth or beach morphology. If the sea has one high tide and one low tide per day, the sea has a diurnal tide. Other type of tidal is transition type; it is the transition between the two types before (Pond and Pickard, 1991; and Stewart, 2002). The tidal has importance role to the environment condition o f water, especially as activator ofcurrent at coastal water, and at other semi-close water (bay, strain, and lagoon) through movement of water surface (up and down). Current of tidal can influence the existence of nutrient in water. Tlie current that entered to tlie bay can increase change of water mass, and also take nutrient fiom various sources and then distributing in su11.ouriding the water (Pariwono in Hanis, 2002).
low tide. These differences should be known because it has re!ation with water depths of the location of tlie culture. Higher differences between them in a location indicated that average of water dcptll ill the locatio~i is small (shallow). Shallow water can influence on water qualiry for growing the grouper, where remnant of feed and iiutricut in bouoni can up and down to water surface caused by tlie wave. According to Mayunar et a/. (1995), the optimum differences of high and low tide for grouper culture is not more than 100 cm.
c. Temperature
Te~nperature is one of pliysical parameters of the water, whicli has importalice rolc for growth of organism. The temperature has direct influence on organism at the water especially on photosynthesis, metabolism, and production cycle (Svedntp
et a/. in Maytrnar et al., 1995). The higher temperature will increase metabolism
l~roccss. 0x1 illc coriiraty. the lower temperature, the metabolism process will decre;tse. Indirectly the temperature can influence on growth of organism at the witlc~. li~iergy, wliiclr llscd Sor growth, ~liilizcd to adapt and to process rrletttbolislll. Increasing water temperature 10°C will increase necessity of oxygen for aquittic ani~nill as nu111ber as twice (W~rdojo it1 Mityunar el a/., 1995).
Wiitcr tc~npcraturc is i~iflucnccd by tneteorology conditions; that is rainfi~ll, evaporation, air Iiumidiiy, air te~nperature, wind velocity, and intensity of the sunliglll. 'I~licrcforc, water surface tclnperature accompanies pattern of seasonal (Nontji, 1993; and Belue~ifeld, and Falkowski, 1997). For example, fish is vety sensitive toward changing water temperature although it is only 0.03'C (Gunarso, 1985). According to Sudjiharno (2001) ideally water temperature for cult~uiiig tlie tiger grouper (l<pinephelus fusco~w~tu~us) is 27-2g°C.
d. Salinity
Salinity is total of salt that dissolved in one liter of water (per mil, %o) or ppt (part of per thousand). Seawater has highest salinity stability if compared wit11 brackish. Changing salinity often occurred in water in near coastal, because it influenced by freshwater that enter through river (Mayunar el al., 1995).
12 in a pond until salinity in tlie pond is equal with salinity in tlle cage. According to Sudjiliarno (2001) and Hasyirn (2003) ideally water salinity for culturilig tiger grouper (I?pinephelus,fusco~~tartrs) is 30.00-33.00 ppt.
e. Transparency and turbidity
According to Jeffiies and Mills (1996) water transparency depended on color alld tlrrbidity. Traiisparency is a ineasurement of penetration of sunlight into the water, determined visually using a secchi disk. Value of transparency is influenced by clilll;~te coliditioll, titiles of ineasurilig, turbidity and suspended solid, and also carefulness of a researcher. Measurement of the transparency is better at clear wcatlicr (Effe~idi, 2003). Based on quality standardization for marine biota, desired valuc of tlie transparency is more than 10 meter and permitted is less than 3 lnetcr (Alio~iym i l l I-lasyi~ii, 2003).
Tul-bidity describes optic characteristic of water and calculated base on amount
of light tllat absorbed and reflected by material in water. Turbidity caused by organic and inorganic materials that suspended and dissolved such as mud, small sand, plankton, aid also other microorganism. Turbidity can influence on fish to breatli. photosyntllesis, and primary productivity of water. In fish culture, ideally value of the t~ubidity is 2-30 NTU (Nepiielometzic Turbidity Unit) (Mayunar et a/.,
1995). Based on quality standardization for marine biota, desired value of it is less than 10 NTU and permitted value is less than 30 NTU (Anonim in Hasyim, 2003).
f Total Suspended Solid/TSS
Total Suspended Solid (TSS) is suspended materials (diameter > 1 pm) and endued in filter of Millipore by diameter of pore 0.45 p.m. Total Suspended Solid consists of mud, fine sand, and also microorganism. The Total Suspended Solid value is influenced by soil erosion that enters to water body (Effendi, 2003). Dcsired value of it to mariculture is less than 25 mgfliter, and permitted is less than
YO rngil~ter (iirionyln 111 Hasyim, 2003). Suitability of water bases on value of tlie
Table 1. Suitability of 'Nater for Mariculture based on Values of TSS
I'SS Values (nil?/liter) 1
-. -- Influences on Fishery's Importance
< 25 ?%ere are not influence
I'arameter of chemical 25 - 80
81 -400
z
400a. Potential of Hydrogen (pH)
Less influences
Less good for importance of fisheries Not good for importance of fisheries
Potential of Hydrogen (pH) is a measurement of concentration of hydrogen ion in tlie water. Its value is very influencing solution of various substances and availability of nutrition for water organism (LPPM-IPB, 2004). Seawater has value of 111-1 is relatively stable, commonly 7.5-8.4. These values influenced by activities of photosynthesis, temperature, disposal of industry waste, and also domestic waste. This v;~lue of pf-1 car1 ir~fluer~ce ori growth of the grouper. The pH of water is less than 5 (acid) or more than 11 (alkali) cause mortality for fish. The pH responds to clia~igcs in: ( I ) tlic coliccntralio~i of total dissolved C02; (2) alkalinity; (3)
telnperature; and for deep waters, (4) pressure. In each case, the magnitude of clla~~gc: v;~l.ics will1 sali~~iiy bcc;~usc the cotice~~tmliol~ of salt i~~flucliccs 011 lhc various equilibrium constants and because several components of sea salt are involved in the acid-base reactions of seawater. The eqtdlibrium pH of surface seawater, for a given temperature and salinity, is the pH of seawater in equilibrium with CO* in the atmosphere. At equilibrium pH, the partial pressure of COz in the seawater is the same as that in rhe ahnosphere (Hinga, 2002).
.
/Optimal value of the pH to culture the grouper is 6.5-9.0 (Boyd and Lichtkoppler in Rusman, 2003). Based on quality standardization for marine biota, desired value of the pH is 6.50-8.50 and permitted is 6.00-9.00 (Anonym in Hasyim, 2003).
Source: Alabaster and Lyod in Effendi (2003)
b. Dissolved Oxygen/DO
14 temperature, partial pressure of gases in air and in the water. Concentration of the oxygen will be lesser if the teniperature, salinity and gases in the water are higher. Nybakken (1997) mentio~ed that the concentration of dissolved oxygen is highly iniporlancc thing for surviving biota at thc water. Besides that, it also can be used as indicator for the pollution of organic matter caused by increasing decomposition activi~ies. Increasing the decomposition will decrease concetitration of the oxygen into tlie water. Generally, fertile water has good oxygen concentration. On the contrary, the water is infertile if its concentration of dissolved oxygen is lowe. l'llcrcforc. the coi~cc~ltration of dissolved oxygen can describe a primary production level for water (LPPM-IPB, 2004). Organisins can life in water if tlie concentration of dissolved oxygen is inininla! 5 mg oxygen per liter of water (5 pptn) (Sastrawijaya, 1901; and Kl,fi, 2004). According to Sudjil~a~no (2001) ideally the co~iccnlralio~~ of the dissolved oxygen for culturing the tiger grouper (fipinephcl71.s
,firscogrr~/o~rr.~) is inore than 5 ppm
c. BOD5 (13iochemical Oxygen Demand)
Biochemical Oxygen De nand (BOD) is total of dissolved oxygen that needed by organism to decompose organic matter in water. Value of the BODS describes indirectly conce~ltration of the organic matter. If consumption of the oxygen by organism is low (described by bigger remnant of dissolved oxygen), concentration of oxidized organic matter is low, and pure level of water !?om pollution is higher. On the contrary, if value of the BOD5 is hidl (described by smaller remnant of dissolved oxygen), concentration of oxidized or6mic matter is high, and pure level of the water is low. Lower concentration of the oxygen ar the water cause metabolism process of aerobe biota disturbed, which finally they can not growth well (Buchari, 1998). Based on the quality standardization for marine biota, desired value of tlie BOD3 is less than 2.50 mglliter and permitted is less than 4.50 mglliter (Anonim in Hasyim, 2003).
Suit;tl)ility of Wxter for Mericulture
Suit;able concept for mariculture
water at present coudition with required parameters for a certain commodity (called a criteria of parameter). These characteristics of water are classified in various parameters in which each of them has value and certain unit. If value of a certain characteristic (parameter of water biopl~ysically at present) is in optimum value or eel-tail1 uilit (criteria), tllc water (locatioil) classified into "very suitablc". 011 tllc contrary, if it is outside optunum value or certain unit, generally the location classified into "suitable", or. "unsuitable", depend on how far their value of parameters ]lave gap compared with optilntlm value that required by a certain commodity for growth.
Con~parison concel~t of parameter for suitability
Concept of suitability in evaluation of biophysical of water is to compare between its characteristic with a required condition. Process for evaluating this snitability can be done by "malching" or "scoring" method.
Suitability level ( V c ~ y st~itablc/suflicicnt suitiiblelless suitable/unsuitable)
Fig. 3. ('o~~i~);irlson I'toccss ofl';~r;~tnctcr for Sutlnbilily (LI'PM-II'R, 2004)
The evaluation by "the matching method" is directly comparing the criteria with the biophysical and chemical parameters, where all the parameters are considered have same influence on toward growth of a certain commodity. Then, the evaluation by "the scoring method" is a certain parameter that is considered has a certain weigh toward growth of corninodity (Fig. 3) (LPPM-IPB. 2004).
Suitability parameters of water for grouper culture
The purpose ofdetern~ining the suitability of water is to know areas of water tliat has potency for culturing the fish in the FNC. Hasyim (2003) concluded tliat tlicre are many biopliysical parameters of water that can be used to detenni~ie the suitability of watcr. Syalnsul and a Trubus Magazine it2 Hasyiln (2003) ine~itioned
that tllere are 8 (eight) of biophysical pitranieiers of watcr Ulat required for culturi~~g grouper in tlie FNC (Table 2).
Table 2. Biophysical Parameters of Water to Culture Tiger Grouper
( l : j ~ i r r c ~ ~ ~ / w l r r s , f i ~ ~ ~ c o ~ ~ ~ / / n / ~ ~ ~ r )
~ o u r c e y Sudjil~anio (1998): and Syainsul and a Trubus Magazine it1 I-lasyiiu
(2003)
Hasyim (2003) in liis research used 12 parameters of water biophysical as criteria to determine the suitability of water for culturing of the grouper. He mentioned that those parameters were considered have higl~er dominant influence on for p o w t l ~ tlie grouper compxed witli other parameters. The parameters are depth; protection froin influences of wind, current, and wave; temperature, salinity, turbidity, transparency, TSS, pH, DO, BOD, E.Colijorm, and chlorophyll-a content.
Weighting stlitability class o f water
In weighting suitability class of water, it is needed data and information of biophysical paraineters of water to growth the tiger grouper that obtained fro111 observatior~ and study of literature. Those data and information are used as inputs to build a classificatio~i of biopliysical suitability of water (called a matrix of suitability). FA0 in Hasyim (2003) mentioned that there are tluee categories of suitability classification of the water; they are order, class, and sub class. Suitability
[image:27.541.95.480.180.364.2]water suitability are (1) very suitable classIS1. This means that the water has not limiting factors that used for ii certain purpose co~lti~luously or they have only s~nall
limiting factors that are not decreasing productivity or benefit of the area; (2) suitable classIS2, this means that the water has big limiting factors that used for ccrt;lin purpose col~tin~~ousiy and they can decrease productivity or benefit of the area; (3) unsuitable class at this timeIN, this means that the water has big limiting factors that used for certain purpose continuously so that they call hamper some possibilities for using the~n. But, the ha~npers can still be anticipated or revised by ccrlain ~ ~ ~ a ~ ~ a g e ~ n w ~ l level ;ind (3) onsuitable class foreverlN2, the water is unsuitable forever because they have limiting factors permanently.
Hasyim (2003) mention,:d that weighting toward all of biophysical parameters of the water based on level of their importance or dominance for growth of tl~c grouper in the FNC. I'arameter that has highest level of importance (very i~nportance) or veql dominance is given a biggest weight. Then, parameter (s) that hasfhave high level of importance (importance) islare given big weight; that are less
I ~ I ~ I I I \scigI~l o S ~ I . C V ~ O L I S ])i~ra~~lclcr, and so on until last oue or some paratnctcrs
finis11 weighted.
I i i il~c cl;~ssilic;~lio~i ol'biol)l~ysic;~l suitability of the water, ;ill of f l ~ e piu?irtie(ers are weighted and scored. The scoring based on level or class of suitability of each of critcri;~ (intetvals of values). For example, for three snitable classes (very sitable, suitable, and unsuitable), if observed value of parameters'is into a value interval of vely suitable, the parameter is given highest score. '[hen, if its value is into a value interval of suitable, it given lower score than previous parameter. Finally, if its value is into a value interval unsuitable, it is given lowest score of previous two parameters. Base on both the weighting and scoring can be built a suitability classification of the water biophysically (a matrix of suitability) for evaluating a suitability of the water as location the grouper culture in the FNC.
Geography Information System (GIs) for Developing Fishery Culture
18 spatial data that has basic of computer, where it has three basic characteristics; that are (1) it has actual phenomena connect with problerns topic and its purposes, (2) it is all cvcnl i n a localion, and (3) it has dimension oftime.
In tlie GIs analysis data and information that required consist of (1) field data, tlicy arc I ; I ~ ~ I I fro111 observation rcsull in tl~c field (result of measuring objects); (2) map data, they are infonnatio~l that is obtained (copied) &om map, paper, or fihn
t11i11 II;IS i ) c c ~ ~ co~~vcrlcd into digital. 1);1ta Illat oblaincd fro~n the map is the licld
data tliat are not required except for requiring ground check; and (3) image data, tl~cy arc data that arc tiika~ li-om production of aerial photo, mid radar.
RESEARCH METHOD
Study Area and Sampling Period
Research is carried out in waters of Mandeh Bay, located u1 regions of a Mandeh Village and a Simpang Carocok Village. The study area is part of Sub Dismc of "Koto XI Tan~san" in Pesisir Selatan Regency, West Sumatra Province. The research is performed for two months fiom April to May 2006 (Fig. 4).
Data Collection
Samptmg procedure
In this research, it is detennined 3 stations and 9 sub stations. They are A, B, and C as stations; and Al, A2, A3, Bl, B2, B3, C1, C2 and C3 as sub stations (Fig.
20
The A, B, and C statio~is are mostly characterized by coral reef and seagrass bed ecosystems. This indicates that biopltysical cliaracteristics of water of these stations could be influenced by these ecosystems. Beside A sub station influenced by ;~bovc two ccosystc~~~s, it also greatly influc~lccd by coastal tourism activity ;ind current and wave of the Indian Ocean since it's position is nearer to a Cubadak Islarttl (as ~ o u ~ i s r ~ i area) and to the Indian Ocean compared with other statiotis. At B and C stations also tliere are mangrove ecosystems and settlement arca. B station is Iiigllly influenced by existences of river rutloff of Mandeli River beside it uiflue~iced by tliose ecosystems of coral reef, seagrass bed and mangrove, and settlement activi~y. Relatively it is influenced by current and wave of tlie Indian Ocean. Then at C station also there is a fish landing area. Beside it influenced by those ecosyste~ns of coral reef, seapass bed and mangove, and settie~nent activity, it is i~~flucl~ccd relatively by currelit and wave of the Indian Ocean.
At A]. A2 and A3 sub s!ations there are ecosystems of coral reef and seayass I)ctl. l'osilio~~s ol'lllrcc tlicsc sub sti~liol~s arc nalrcr to center ;tclivily of llic co~l~tiil tourism and to tlie lndian Ocean than otlier sub stations. Therefore their biophysical c11i1r;ictcristics of water are greatly influenced by ecosystems of coral reef and seagrass bed, coastal tourism activity, and current andwave of tlie Indian Ocean. For A1 sub station it is highly influenced by current and wave that go into the bay Ilirougl~ a Teraju Strait, and also by ecosystems of coral reef and seagrass bed. For
143 sub station it is l~igl~ly influenced by current and wave that come from a Sironjong Strait. Meanwhile for A2 sub station is influenced relatively by currents and waves come from two these straits. Three these sub stations are greatly influenced by ecosystems of coral reef and seagrass bed. Then, A2 suh station is influenced oT/er by coastal tourism activity since it's position is nearer to center activity of tlie coastal tourism than other sub stations. However A1 and A3 sub station is influenced relatively by coastal tourism activity.
landing activity, but this sub station is hid~ly influenced by settlement activity. 'I.lle~l C3 sub station is higllly influenced by fish landing activity, but this sub station is relatively influenced by settlement activity.
IDala that needed i n this research consist of primary and secondary data; that ;Ire tlata il~iit relates with grcwth requirements of the tigel grouper (l~pb1ej~I1elu.s
/ ~ , . Y C ~ ~ J , ~ ~ I / / ~ I / I I , Y ) i n Floating Nct:; Cage (FNC). The data are biophysical data of water of the bay; tllat are data of biological, physical, and chemical (Table 3 and 4).
Table 3. Primary Data
Table 4. Secondary Data
9.
10.
Chlorophyll-a pH
Note: "SI-10-NAFN" = A Service of 1-lydro-Oceanogapl~y of National Armed
Forces of Navy
Tools
-
- 3. 4. 5 .l'llese data are obtained frorn observation directly a study area, analysis at labomtory, and rcfcrences study.
& l i t e r - No. 1. 2. Units
-
-
ParametersRequirements of growth of tiger grouper
Lklsc nlar, orblanticli Bay
Type of tide
Wave height (meter)
. . .. . .- -. . . . - . . - -- Current velocity (cmdsec)
in Laboratory
Absorplion; in Laboratory
Field measurement
Sources of Data Collected from some references
Collected fmrn "Bakosurtannl"
-
meter
-- -
cidsec
Spectrophotometer
pH-meter
,
Collected from "SHO-NAFN- Station of Teluk Bayur" Collected from "Bappeda of West Sumatra Province (2006)"
~ollectcdfrom Ningat (2004)
-
-
~
[image:32.539.75.485.108.706.2]a. Parameters of tide, wave, and current
for determining a tide type and a tidal range of tlie bay water it is carricd ont analysis toward tide data of the bay that obtained from the prediction of tide data annually tbr Indonesiiun arcliipelago in 2006 published by a Service of Hydro- Occanogrnpliy of National Armed Forces of Navy for a Station of Telulc Bayur, West Sumatra Province. The required tide data are the data on April and on May (at this researcll canied out), and also tlie data on February (the sun in the North), on .IIII~ (Ihc sun in lllc equator), and on December (the sun in tlie South).
Determining the tide type based on value of Formzhal (F); that is a ratio of a nuniber of a~nplitude of diurnal tides components (AKI+AOI) and a number of a~nplitudc of se~nidiurnal tides components (AM2+AS2) (Rawi, 1994). Then, determining tidal ranges based on some of tide elevations; tliat are a Highest High WIIICI. I..cvcI (IIIIWI.), i~ MC~III Iligl~ WIIICI. LCVCI (MIIWL), a Men11 SCII L.CVCI
(MSL). a Mean Low Water Level (MLWL), and a Lowest Low Water Level (LLWL). Delenni~~alio~~ 01' Lllese tide elevations is by analysis the111 directly on a
tide graphic obtai~icd.
AKI Anlplih~de of diurnal tides components caused by pull force
between the moon and the sun
Amplitude of diurnal tides colnponents caused by pull force the moon
Amplihide of se~nidiurnal tides components caused by pull force the moon
Amplitude of semidiurnal tides components caused by pull force the sun
Semidiurnal (tide of double type) Mixed tide prevailing semidiurnal Mixed tide prevailing diurnal Diurnal (tide of single type)
Wave and current
ptrblislicd by "Bappcda" of West Sumatra Province in 2006, and also from a Filial I<cl)o~i o 1 1 i 1 S c o f I Area J t i l i i o ~ for Coastal T O I ~ ~ ~ S I I I i l l
Mandell Region, West Sumatra Province, published by "DKP-UBH in 2001.
b. Parameters of depth, temperatlu'e, and transparency
I);II;I of'\vi~lcr tlcpih* ~ C I I I ~ C ~ ~ I ~ ~ I ~ C :111tl I~:~r~spftrct~cy :rrc r~l)lirii~e(l dirccJly in :I study area. Observation is carried out three times on each of sob stations; at 3, 23 April, and 3 May. For one observation is camed out three times measuring.
Water depth is ineasured by using a depth finder. ln tllis research, the depth finder is built by nylon line o f 5 0 lneter in length with a tin of 2 kilogram in weight as ballast. T l ~ e depth finder is gone down in waters mitil the tin touched water bottom.
Water temperatures are measured by using a thennometer. Tile thennometer is sunk into water using a nylon line of 2 meter in length. The thermometer is lifted to water surface i~inncdiately after it sank in the water until 1.5 meter.
Water transparency is measured by using a secchi disk. In this research, tlie secchi disk is built from a white plate and combined by nylon line of 20 lneter in lengll. Recording values of tlie water transparency is camed out if the secchi disk or. 21 white platc has not appeared from the water surface.
c. Salinity, turbidity, Total Suspended Solid (TSS), Dissolved Oxygen (DO), 130D5, content of clilorophyll-a, and Potential of Hydrogen (pH)
~ I S I Ir ~ ~ c i c r s ~ I I S s l i i y ttrrbitlily ( N J / N L J I J J ~ / ~ Yitr.hi(li!~*
(/nil), Total Suspended Solid CrSS), Dissolved Oxygen (DO), BODj, content of
clilo~~opliyll-a, and l'otenlial of Ilydrogeii (pH) are carry out by analyzing water samples collected from a study area. Collecting the water samples is canied out composi!cly from water surfi~ce till its bottom using "a1 aqua bottle" ( I liter).
24
Measuring parameters of the salinity, the Dissolved Oxygen, and the Potential of Hydrogen is carried out directly in study area by analyzing the water saniples. Yet, for other parameters (turbidity, Total Suspended Solid/TSS, BOD5, and content of cl~loropliyll-a) Ineasurcments of their water samples is carried out at a Laboratory of SMAK-Padang, West Sumatra Province. Before the water samples are znalyzed, they are
cnicrccl into lpl:~slic bo~tlc o f 1 litcr ill volunic, covered by "dark bays", and then slorcd inlo
Styrofoam. This is carried out to w e quality of the water samples.
1)ata Analysis
i\~~;llysis of biol~l~ysicill clli~rilcteristics of water
Analysis of biophysical characteristics of the Mandeh Bay waters is carried out to get description of spatial distribution of the water parameters on stations and sub stations, and also to get description of correlations among the parameters. Analysis of data is calried out by a Principle Colnponent Analysis (PCA) using software of SI'SS vcrsio~l 12.0. Accordini: to 13c11gc11 (2000) and Sima~rtorti (2005) the PCA is ;I statistical method of descriptive. Its airn is to show data in a graphic and also to show rr~axirr~c~rr~ ir~fonr~atior~ in a data irlalrix. The data matrix in this research is sub stations as row, and biopllysical parameters as variable of quantitative (colmnn).
Before analysis of the PCA analysis is formed, all the data should be combined: that is with concentrating and reducing them, because the data have not the same unit of measurernant and variance. The concentration is differences between value of initial parameters and average value of the parameters (Legendre and Legendre, 1983 in Buchari, 1998). Then, the reduction is result of dividing between parameters that have been concentrated with variance value of the parameters.
C = X i j
-
HjWhere: C = value of center
Xij = value of initial parameter Xj = average value of parameter
Where: R = value of reduction C = value of center
Rclationship bctwceli two parameters is determined by approaching corrclatioli rlratris c;~lctil;~~cd by syritl~clic ir~dcx (1,udwig and Rcyt~olds. 1988 it1 Duchari, 1998).
Where: Bsxii = matrix of correlation, rij
Ass11 = matrix of synthetic index. aij ~ ' s x r l - itialrix oflcar~sposc
Idillear correlation of two parameters that is calc~llated base on its synthetic index is variance of the two parameters that has been a l ~ a d y normalized. Of all possiblc syntlictic ilidcx, lirst, tlic I'CA analysis searches index that shows ii inaxilnuln variance of its sub stations. The index is called a first principle component; that is a first main axis (FI). A certain proportion of total variance of sub stations is explained by a principle component. Second, the PCA analysis searches a second principle component (F2) that has nil correlation with the first principle component (Fl). 'Tlie second principle component (F2) gives biggest information as co~nple~nent for the F1. These processes will go continuously until getting principle component to-p that can explain smallest par1 of information. The prillciple component analysis used measurement of Euclidean distance (i.c. quadrate total of diffeerencc among individual for correspondence variable) that based on a fonnula as follow:
P
d2 (it i') =
C
(Xij - ~ i ' j ) ~j = 1
Where: i , i') = a row
j = index on column, varied among 1 - p
The s~naller the Euclidean distance between two sub stations, characteristics of tlic watcr will bz illore reseliible for the two stations biologically, physically, and chemically. Stations that have been grouped (results of analysis of principle cornpoi~cilt), the11 colltirmcd by classificatio~i ordination. The confinnatioll is calculated froin the Euclidean distance by aggregation criteria base on an average linked.
i\~l;llysis ol'1~ioj)liysical suitability of water (potency)
GIS Version 3.2. The analysis consists of three process; they are classifications of suitability of water parameters biophysically (process I), preparation of thematic nlaps (process 11), and detern~inatioll ofsuitable water (process Ill) (Fig. 5).
I
I
+
I Classes of s~~itnbility s
I I
+
I Ibiop1rysie:d palameters
i
,
I I
I
suitability for tiger grouper culture in FlVC
. . .
Cl;~ssilic:~tioa bioplrysical data ofwrlcla
I
+
Vtst-I~~t'i~tg l ~ i t q ~ l ~ y s i c ~ ~ l 1li111r of
wirters
1:
Fig. 5. Flowcnart for Detemlining Potential Waters to Culture Tiger Grouper (f$~it~ep/leltl~ f2ucogztllalz~~j in Floating Nets Cage (FNC) (Modified from Hasyim, 2003)
I
+
II I I I ~ ~ C or I biol~l~ysic:~l d:rtir of
t vector forlllat
\
.
... ,I - - -
a. Process I (Classifications of water suitability based on biophysical parameters)
Process 1 is process in deterinining classification of suitability for each of water parameters biophysically appropriated with requirements of growth of the grouper. The processes are { I ) determining confines of value (criteria) for each ~x~ra~ncter, and (2) weighting and scoring them to get classes or suitability criteria; that are vely suitable (Sl), suitable (S2), and tulsuitable (N) (Appendix 3).
[image:37.544.81.488.102.478.2]2) Suitable (S2): Waters have potencies as location for culturing- the grouper because the waters have lnininlal requirements to growth it.
3) Unsuitable (N): Waters 11irve not pote~rcies as loculion for cullurii~g tlrc grouper because the waters have limiting factors to growth it.
Delenninitig the confines of v a l ~ o (criteria) eacl~ parameters based on various parameters that have relationship with the growth requirements of the grouper. Weigl~ting each the parameters based on their importance level against the grouper's survival. Then, scoring base on suitability level at the each criterion.
1) Score 1, if a value of observed parameter unequal with criteria of a S1 or a S2. Tlie parameter classified into a N,
2) Score 2, if value of observed parameters equal with criterion of a S2, 3) Score 3, if value of observed parameters equal with criteria of a S1.
The suitable value (a final value) of waters for Mandeh Bay is a total of suitable values of all parameters, compared with an interval of final values and suitable classifications (Table 5). The suitable value is present status of Mandeh Bay waters as location to culture tiger grouper (Epinephelzrs fuscogui/n/lrs).
('1 ~ I ~ S I ~ ~ I I I ~
.
.. ' ' interval of final values and suitable classification of the waters is based on a suitable mat~ix of waters that classified before (Appendix 3). Values total (score inultiplied weigl~t) of iill parameters of very suitable class (Sl) reduced bp values total of all parameters of unsuitable class (N), and divided by 3 (three) (total of suitable classification).Table 5. Interval of Final Values and Suitability Classification of Waters
b. 11 (Preparing thematic maps for each biopliysical parameter) Classes of Waters
A B C
Process I1 is process preparing thematic maps for each biopl~ysical paralneter. These parameters are water depths, water temperatures, salinity, chlorophyll-a, Oxygen Dernand (DO), turbidity, transparency, BOD5. Total Suspended Solid
(TSS), i l l ~ d pH. Results of process 11 are thematic maps of these parameters. These maps are used for preparing a thematic nlap part of suitable waters (potencies) to culti~rc l i p grouper (l~pit7epl~el~i.s.fi~.~co~~~tlal~rs).
Interval of Final Values 2.34-3.00
1.63-2.33
1 .OO-1.67
Suitability Classification Very suitable (S 1 )
28
c. Process I11 (Preparing a thenlatic map part of suitable waters (potencies))
Process 111 is process determination of part of potential waters to culture the grouper. In this research, potential waters are part of waters that has suitable requirements biophysically to growth the grouper.
111 this process, a spatial analysis is camed out by teclmique of overlay. The spatial analysis is used to evaluate waters as area of geo~~aplly. The evaluation is carried out by spatial model; that is arranged by a basis grid, and helped by a tool niodel builder. TI)' spatial model that has been builds then presented in a flowchart (Fig. 6). This model helps evsluating geography areas of suitable waters to culture (lie grouper based or1 a stritable matrix of waters (Appendix 3). 111 this spatial ;~i~i~lysis, data of biophysical parameters (point), interpolated into grid, and its result i~rfi~tigcd ill Sol-111 of a rlicmatic map.
. , . . . . ,.... . . .
Itiniil
... Proccss . .
i
,.. , , . : : Outnut i i
Fig. 6 . Flowchart of Process Inteipolating Point Data in Model (Wardjan, 2005)
Overlay is process conibi~ti~ig somesuitable water maps; come froin sonte I)at.ailleters, becoiiii~lg a suitable waters map that represented all overlaid paralneters (Hasyi~n, 2003). Tl~e overlay is carried out on all suitability parameters biopliysically. 17irsl, tlie overlay is carried out on parameters that have lowest values. Then, result of this overlay overlaid again with other one or some pal-ameters that lias or have higher values of parameter than previous parameters. The overlay continues until all parameters overlaid. In this research, there are six steps of overlays (Fig. 7). In each step is canied out classification of suitability and scoring again to detennine new classes of suitability (very suitable, suitable, and unsuitable) in location of overlay's result, and given new scores at each the class of suitability.
ovcrlay base on the value o: interval, and (4) giving score value again in new suitability class in getting vi.lue ol' score way from one of parameters that has lrigllcs~ v;rluu of wcigl~ t1r;111 ot!lcrs (I iirsyiil~, 2003).
17ilial rcslllts of tlie overlay arc waters of very suitable (Sl), suitable (S2), and c ~ ~ ~ s u i l ; ~ b l c ( N ) for culturirrg tiger gl.ol~l)cr (/:j,it~e[)/~el~rs fu.~cogullu/~rs) in Floalir~g Nets Cage (FNC).
Salinity
TSS Transparency Chlorophyll-a
...
...
suitability & giving score
,
...Overlay Step 2
:
< ... IClassification of suitability & giving scol.e
Classification of suitability & giving scolr
Overlay
I
ITig.7. flowclc;~r~ o f 0verl:ty to All Biophysical Paiametcrs (Modilied fi.oi11 Hasyirn, 2003)
Wave lleigllt ...
Current velocity ! Ste11 3
. . . Overlay
I
C:lassificatiou of Wind velocity
soitability & glviiig scoxz I I
I*
...I'ROFIIX OF MANDEtI BAY COASTAL AREAS
Geography Conditions
A Matide11 Bay is a part of tiiarine aid coastal areas of Pesisir Selatali District, West Sum;ltls I'rovillce. Ad~~~ii~istr;ltively, t l ~ e bay is a part of regions of Mandcl~ Village and Simpang Carocolc Village in Sub district of Koto XI Tarusan. A Mandcl~ Village is one of threo "kampung" (villages) in "Nagxi Niuiggalo". Others two villages in the "Nagari Nanggalo" are Nanggalo Village and Sungai Tawa Village. 'fhen, Sil~~pang Carocok Villi~ge is orie of four vil1;tges in "Nagari A I I I ~ ; I I I ~ Pulai". Others three villages in the "Nagali Ampang Pula?' are Teluk Raya, Bat11 Kalang and Pulau Karain Villages. A "Nagari" is a smallest government of sub district government in a govenlment system in West Sumatra Province.
The Mandeh Bay in tlie North borders on Sungai Nyalo Village, in the South is on Bat11 Kalang Village, in tlie East is on Mandeh Village and Simpang Carocok Village, and in the West is on Cubadak Island. In the Northwest there is Sironjor~g Stri~il i111d ill t11c SOII~IIWCSI is T C I - ~ ~ I I Strait. Geograpl~ically Mar~dcl~ Ray is s t 01"
12' 10"-0Io15'05" South Latitude (SL), and 100°25'2~'-100025'45" East Longitude
(EL).
Topogrsphy of mainland around Mandeh Bay is bumpy. Generally its mainland in the West is lowland by its slope is 0-5 %. Its mainland in the N x t h is upland (range of hills) by its slope is more than 40 %. Altitude of the Mandeh Bay mainland from seawater surface is 2-100 meter. Area of the Mandeh Bay is about 2673 Ha. where its length is 6.75 k ~ n , and its width is 3960 km. Tlie bay has four small islands; they are Sironjong Besar Island (8.15 Ha), Sironjong Kecil Island (5.55 Ha), Setan Besar Island (3.00 Ha), and Setan Kecil Island (1.50 Ha) (Ningrdt, 2004).
Clin~ate ;111d Oceanography Conditions Climate
rainfall yearly is 3297 iiimdyear with a ~iulnber of rain days is about 156 daydyear. Wind velocity is approximalely 5-20 km/l~our or 1.39-5.56 knots, especially in daytiliie (Ningrat, 2004).
Water depth of tlie Mantleli Bay varies, h 1 1 1 0 to 30 meter. Deeper water is in the North of the bay or in the Northwest of the Cubadak Island i.e. from 15 till 30 meter. Distalice of the water is about 500-1000 meter fiom coastlu~e, whereas shallower water is in the South of the bay i.e. fiom 5 till 15 meter. Distances o f the water are about 1000-2000 m froin coastline (Bappeda of West S~unatra Province, 2006).
Bathyrnetry Map of lvlandeh Bay. Pesisir Selatan Regency
I J
Fig. 8. 13i1lliy111~11y o r (lie klatideli Ray Water (Source: Bappcda of West Surnalr I'rovince. 2006)
[image:42.547.81.486.175.650.2]32
of the bay i.e. approximately 1.2', where its depth are from 0 till 20 meter, and its distances are 2000 meter fiom coastline. Then, for water in tlie East and tlie North of the bay have almost same slopes i.e. about 1.7", where their depth are from 0 till
15 nictcr. and their distances are 750 meter fiom coastline (Fig. 8).
'l'idc is bcsl linowi~ as rise and li~ll ol'thc sell around
thc
edges of the land. 111s o ~ ~ ~ c coiisli~l i~rcils tl~crc is II rcgulin. pi111a.11 of one lligl~ lidc ant1 one low tide cscl~
day; this is a diurnal tide (Prandle, 1982; Stephen, and Pickard, 1991; and Davies, 1992). 111 other areas there is a cyclic high water-low water sequence that is repeated twice in one day; this is a semidiurnal tide. In semi diurnal tidal pattern, both high tides reach about thr: same height, and both low tides drop to about the same level with each cycle. A tide in which the high tide regularly reach different heights and low tides drop regufarfy to different level is called mixed tide (Mann,
and L.:~zics. 1996; Svcrdrup, l'>uxbu~y, and Duxbury, 2006). According to Triahnodjo (1 999) there are f o x types of tides; they are a semi diurnal tide, diurnal tide, inixed tidc prevailing semidiumal, and mixed tide prevailing ditulial.
Based on the tide tables t)f Indonesian Archipelago published by a Service of' Hydro-Oceanography of National Armed Forces of Navy in 2006 for a Station of Teluk Bayur, West Sumatra Province, predicted that tide type for the Mandeh Bay is a inixed tide prevailing semidiurnal (F = 0.42). In one day tliere is twice highest water and twice lowest water, but height and cyclic for both the highest tides and lowest tides are different. A maximum tidal range of the Mandeh Bay water is 1.40 meter on April, and minimum is 1.03 meter on Febiuary. This prediction based on data of tides 2006 when the sun at the North of the earth (on February), when this observation did (on April and May), when t
