Aquaculture Research, 1996, 27. 255-2f)O .

Penaeus monodon (Fabricius) production related towater quality in East Java, Indonesia

A M Hariati,' D G R Wiadnya,' M W T Tanck.^ J H Boon^ & M CJ Verdegem^'Universitas Brawijaya, Fakultas Perikanan, Malang, Indonesia, and -Wageningen Agricultural University, Department of

Fish Culture and Fisheries, Wageningen, The Netherlands

Correspondence: J H Boon, Wageningen Agricultural University, Department of Fish Culture and Fisheries, PO Box 3 38, 6700 AH

Wageningen, The Netherlands

Abstract

On two shrimp farms in East Java. Indonesia, a total of16 tambaks stocked with Penaeus monodon (Fabricius)were monitored for water quality during one grow-ing season. The water quality parameter values werecompared with production characteristics. Rangesof parameter values remained between acceptablereference values. Influences of farm, tambak and timeon water quality were significant, Tambak productionwas explained for 25% by water transparency Ob-served water quality parameter values could not be areason for recently described decreased production.Therefore, other factors should be investigated.

Introduction

Penaeus monodon (Fabricius) production in East Javaincreased from 1000 to 30 000 Mt between 1980and1991. At intensive farms, yields of 15-2OMtha-'year ' were easily reached with no serious diseasesproblems (Hariati. Wiadnya, Prajitno, Sukkel. Boon &Verdegem 1995), However, from 1992 onwards, theproduction per hectare decreased dramatically, somefarmers losing nearly their entire crop in two out ofthree production cycles. Although production losseswere more severe at intensive farms, semi-intensiveand extensive farms were also affected. Similardecreases in production were also experienced in otherAsian countries (Anderson. Shamsudin, Shariff &Nash 1988; Un 1989; Fulks & Main 1992).

Different causes were named in relation to theproduction decrease, infectious (Chantanachookin,Boonyaratpalin, Kasoornchandra et al. 1993) and

non-infectious (Millamena 1990; Anonymous 1994)diseases being the principle reasons. Many shrimpdiseases are triggered by sub-optimal water qualitywhich adversely affects tambak production in turn. Toinvestigate the relationship between production andtambak water quality during intensive mono-cultureof P. monodon, two farms each with eight tambaks weremonitored. Production started in late November 1993,Water quality values were linked to tambakproduction.

Material and methods

Farms

Decreases in shrimp production were greater in North-East Java than in other parts of East Java (Hariati et al.1995), Therefore, two farms in the Probolinggodistrict, NE Java, were selected on the basis of farmer'swillingness to cooperate and the availability of a goodtambak production administration.

Farm 1 consisted of nine similar-sized tambaks. oneof which was used as reservoir. All production tambakswere used for P. monodon culture. Both coastal water(pumping) and fresh water (deep well) were availableon farm. Mixing of marine and fresh water wascarried out in the reservoir, which also served as arudimentary sedimentation tambak, Tambak bottomswere dried and successively treated with lime andfertilizer prior lo filling. Four paddlewheels aeratedeach tambak during the whole culture period.

Farm 2 operated 44 tambaks eight of which wereused for P. monodon production, while the others wereused for P. merguiensis (de Man) mono-culture, ormixed culture of P. monodon and P. merguiensis. The

© 1996 Blackwell Science Ltd, 255

Shrimp production and water quality A M Hariati et al. Aquaculture Research. 1996. 27, 255-260

water supply came from the same source as for farm 1hut did not pass through a reservoir. Fresh well waterwas also availahle on farm and could he pumped toany of the tamhaks. Tamhak preparation was similarto that for farm 1, hut four paddlewheels per tamhakwere also used. Only the P. monodon mono-culturetamhaks were included in the study.

Farm technicians recorded the daily water qualitymeasurements and reported to one of the authors whovisited the farms at hiweekly intervals.

Farmers replaced tamhak water occasionally, up to15% per day, hased on ohservation of water colour andcoastal water quality. Sea water was mixed with freshwater to avoid salinity changes. Both farms appliedantimicrohial drugs, mainly oxytetracycline, to alltamhaks at least once during the production cycle. Forunknown reasons, farmers prefer to apply the drugs 5days hefore full moon.

Water quality parameters

The farm managers were asked to monitor the waterquality of a numher of tamhaks on their farms duringone culture period. They measured dissolved oxygen,temperature, salinity. Secchi disk transparency and pHevery day. Nitrate, nitrite and ammonia contents weredetermined twice a week.

Because dissolved oxygen levels were high in theafternoon, only midnight (2400 h) and early morning(0500 h) values were considered in the analysis, whiletemperature, pH and salinity were measured at 0500and 1700 h. The Secchi disk transparency wasmeasured at 0900 and 1700 h on farm 1 and at0900 h on farm 2. Dissolved oxygen and temperaturewere measured close to the tamhak hottom. while pHand salinity were taken at the surface.

Production related parameters

Upon harvest, the farmers provided information on theyield (Mt ha"' crop"') of each tamhak monitored.

Calculations and statistics

The average overall value and weekly averages for eachparameter monitored were calculated per tamhak.Differences between overall means per tamhak wereanalysed hy t-test.

Variations in water quality were analysed usinggeneral ANOVA, factors heing farm, tamhak. week and

sample time. Overall means of water qualityparameters measured and the tamhak productionrecorded were analysed in a Pearson correlationmatrix. Because salinity decreased gradually over timein.all tamhaks, the slope of the regression week-salinityper tamhak was used for the latter analysis.

For all statistical analyses, the STATISHX (1985)program was used.

Results

The overall means of water quality values andproduction per tamhak are given in Tahle 1. Values ofthe two farms were similar, hut there were significantdifferences hetween the overall means per tamhak(P<0.01).

The variation of the early morning water quality perfarm over several weeks is reviewed in Fig. 1. Earlymorning dissolved oxygen levels never dropped helow2.6 mg 1~'. while the weekly mean average was nothelow 3.7 mgl"'. Especially after week 4, earlymorning dissolved oxygen levels on farm 2 were lowerthan on farm 1 (Fig. la). The salinity decreasedgradually during the production cycle, the highest andlowest levels observed heing around 30 and 10%o,respectively. Variation in salinity hetween tamhaks washigher during the first half of the production cycle, asindicated hy the standard deviations (Fig. lh). Theoverall average water temperature was 29.3 °C.During weeks 5 and 6. there was a dip in temperatureon hoth farms (Fig. lc). Differences in pH rangedhetween 7.8 and 8.8 (Fig. Id), with an overall averageof 8.3 7. Mean Secchi disk transparency decreased from30-3 5 cm initially, reaching ±20 cm towards the endof the production cycle (Fig. le). Notwithstandingsimilarities, water quality parameters were influencedhy farm, week and sampling time (general ANOVA,P < 0.01)(Tahle2). All parameters changed overtime.Readings were different hetween early morning andafternoon, heing approximately 0.3 mg 0,1"', 0.7%o,2.6 °C and 0.2 for DO, salinity, water temperature andpH. respectively. Pearson correlation coefficientshetween the different parameters are given in Tahle 3.Yield is negatively correlated with transparency(Secchi) (P < 0.05) and nearly with DO. Furthermore,DO is negatively correlated with pH (P < 0.05) andnearly with water temperature (P < 0.10), while it ispositively correlated with transparency (P < 0.05). Onhoth farms, ammonia, nitrite and nitrate were helow0.02. 0.1 and 25 ppm, respectively, during the wholeproduction cycle.

256 ©1996 Blackwell Science Ltd./iqiidcu/tureRcseflrdi. 27, 255-260

Aquaculture Research, 1996, 27, 255-260 Shrimp production and water quality A M Hariati et al.

I

oa

B

1a

•a

s

•a

TJ £

b o

CO OiC, siO) If)

o" o ' ST S" i n ' S ' S r o ' t f r o o a o o o m o i c o c M O ^

c o o o o o i c o i n c o r ^ ^ o ^ o c o r - h ^ o o ^ t oC M T - O U I T — p t o h ^ c o o ^ ' ^ c o p c o i n p t po i c o d o i d o J d ^ o o c o c o h - c o c o o o c o c oT - i - < N ' r - C M r - C v ] ' » - ^ i - T - T - ^ T - C M T - r - T -

oocoodcdoocoodcocd cdodcdoooooooooooo

in 'co"co^PS5"iocoocM ' ' ' ' ^ ' ^ I G S i c ^ S r ' mi n - ^ ( O ' < t c o c D T r ' : t p h - r o r ^ c q q o q p r ^ c D

c D t D O J ' ^ r ^ t p i - o o ; -

c j i o d o i o i c j j a i o j r ^ c do j c a o j c v i o a o j o j o j c j

t - ; C \ j c q ' * u ) < D f ^ o q ©

c o O ' - o j t o m m o o j

iq !? ^ S S S §

© 1 9 9 6 Blackwell Science Ltd. AqMacui£ureKfiscflrdi. 27* 255-260 257

Shrimp production and water quality A M Hariati et al. Aquaculture Research. 1996. 27, 255-260

(a) OXYGEN FLUCTUATIONSAT 05.00 AM

0 2 4 6 8 10 12 14

WEEK OF CULTURE

35

32

29

26

| ' 2 3>t 20

14

11

8

S

b)

:

SALINITY FLUCTUATIONSAT 05.00 AM

0 2 4 6 8 10 12

WEEK OF CULTURE

14 ie 18

TEMPERATURE FLUCTUATIONSAT OS.OO AM

0 2 4 6 6 10 12 14 16 18

WEEK OF CULTURE

S 10 12

WEEK OF CULTURE

Figure 1 Weekly mean of water-quality parameters for farms 1 (-) and 2 (—) with standard deviations: (a) oxygen: (b) salinity:(c) temperature: (d) pH; and (e) transparency.

Discussion

Despite the variations observed, all values of theparameters meet the water quality requirements forshrimp production (Cawthorne. Beard, Davenport &Wickins 1983; Allan & Maguire 1991: Garcia & Brune1991; Lee & Wickins 1992; Parado-Estepa. Llobrera.Villaluz & Saldes 1993); early morning dissolvedoxygen concentration was between 3 and 5 mg 1"';salinity was above 15%o, being above 30%o during the

first weeks of the grow-out period, which is preferablefor postlarvae (PL) and juveniles; water temperaturewas between 26 and 30 °C; water transparency wasbetween 20 and 30 cm; and the pH was hetween 7.8and 8.5. Furthermore, the ammonia, nitrite andnitrate levels in all tambaks were too low to have anegative effect on survival or growth (Allan, Maguire& Hopkins 1990; Chen & Chen. 1992).

Variation in water temperature between farms wasmainly caused by differences in tambak depth. The dip

258 © 1996 Blackwell Science Ltd, 4quocu/JureRe.9cflrc/i. 27, 255-260

Aquaculture Research, 1996, 27, 255-260 Shrimp production and water quality A M Hariati et al.

Table 2 P-values for the ANOVA onwater quality parameters using allvalue measurements (n = 502) withfactors farm, week and time of day.The number of repetitions was eight*

Source of

variance

Farm (A)

Week (B)

Time (C)

A*B

A*C

B*CA*B*C

P-values for water quality parameters

df

1

151

151

1515

DO

0.000

0,000

0,000

0,000

0,763

0,001

0,001

Secchi

0,016

0,000-

--

-

-

t

Temp

0.000

0.000

O.DOO

0.000

0.000

0.000

0.000

PH

0.000

0.0050.000

0.030

0.1910.000

0.240

Sal

0.244

0.000

0,004

0.000

0.107

0.000

0.895

* Secchi disk transparency was measured once a day at 0900 h, dissolved oxygen andtemperature were measured at 0500 and 2400 h, and pH and salinity were measured at0500 and 1700 h.' DO, dissolved oxygen (mg 1"'); Secchi, Secchi disk transparency (cm); Temp, temperature(°C); Sal, salinity (%o).

Table 3 Pearson coefficients of correlation* between overall means of water-quality parametersmeasured in 16 tambaks and crop yield'

DO

pHSal-b

SECCHI

TEMP

PROD

DO

X

-0.604

0,023

0,515-0,486

-0,458

pH

X

-0,284

-0,125

0,524

0,314

Sal-b

X

-0,197

-0,211

0.274

Secchi

X

0,012

-0.510

Temp

X

-0,013

Tambak prod

X

f DO, dissolved oxygen (mg |-'); Secchi, Secchi disk transparency (cm); Temp, temperature (°C); Sal-b,slope of regression week-salinity (%o); Prod, yield at harvest (Mt ha"' year').*/->0.497, P<0,05; r> 0.623, P<0.01.

in temperature during weeks 5 and 6 was related tocloudy weather and heavy rainfall. Temperature wasmonitored close to the bottom so diurnal variationsaffected the whole water column. Nevertheless,temperature remained favourable to shrimp cultureduring the entire culture period.

The higher afternoon salinity values were causedby measuring salinity of the thin surface water layeralong the border of the tambak, evaporation beinghigher in the afternoon than early morning. For awhole tambak. diurnal salinity variations wereconsidered to be negligible because of constant mixingof the water column by paddle wheels. Decrease ofsalinity during the production cycle was caused byrainfall. The rainy season in East Java starts in lateOctober and lasts till the end of April, High salinities,which were observed at stocking, favour PL survival(Chakraborti, Ravlchandran. Haider. Mandal&Sanfui

1985). while the lower salinities observed towards theend of the production cycle when the tambak shrimpbiomass is high, reduce the occurrence of Vibrio spp.Infections (Sindermann & Lightner 1988), Vibrio spp,are often involved in shrimp diseases in the tropics(Sunaryanto & Mariam 1986).

The principal water quality constraint wasthought to be the early morning dissolved oxygenconcentration because preliminary observations ofearly morning dissolved oxygen levels at thebottom in semi-intensive tambaks were sub-optimal(1 mgDOl'), However, dissolved ox>^en concentrat-ions remained favourable to growth (Allan & Maguire1991) and did not cause stress (cf, Garcia & Brune1991) during the entire production cycle. In East Java,most farmers never measure dissolved oxygen levels,but rely on observations of the water colour combinedwith excessive use of paddlewheels. Water trans-

©1996 Blackwell Science Ltd. A«uflcui£urei?eseardi, 27. 255-260 259

Shrimp production and water quality A M Hariati et al. Aquaculture Research. 1996. 27, 255-260

parency is inversely related to the concentration of

algae and suspended particulate matter. From the

statistical analysis, it was clear that decreased water

transparency was related to an increased tambak

production. The reason for this heing a higher survival

rate (SR) caused by the availability of algae and

particulate matter to the shrimp at the hottom. which

graze on them. This availability is caused hy constant

mixing hy paddlewheels. which were installed in

all tambaks. This is in accordance with results

obtained by Hariati et al. (1995), who observed a

significant positive relationship hetween production

and SR. Tambak water is partially exchanged

when algae die-offs are expected, as indicated by

changing water colour. In the present study, this

methods was obviously effective in preventing

mass shrimp mortality caused by oxygen depletion.

At present, farmers indicate that intensive farms in

the region experience production failures in two out

of every three production cycles, while consistently

applying the same management. If so. it is unlikely the

production failures would be linked to sub-optimal

dissolved oxygen. pH or salinity levels. In addition,

extensive and semi-intensive farms also suffer

production losses. Therefore, other environmental

factors may play a significant role. Because the

concentration of shrimp farms in NE Java is high,

coastal waters are severely contaminated with organic

wastes. Industrial and domestic pollution, which were

not measured, can also contribute to sub-optimal

water quality for shrimp culture. Further research is

needed to determine the mechanism which triggers a

negative feedback on production in all types of shrimp

culture farms in East Java.

References

Allan G.L.&MaguireG.B.(1991)Lethallevels of low dissolvedoxygen and effects of short-term oxygen stress onsubsequent growth of juvenile Penaeus monodon.Aquaculture 94. 27-37.

Allan G.L., Maguire G.B. & Hopkins S.]. (1990) Acute andchronic toxicity of ammonia to juvenile Metapenaeusmacleayi and Penaeus monodon and the influence of lowdissolved-oxygen levels. Aquaculture 9 1 . 265-280.

AndersonI.G.. ShamsudinM..ShariffM. &NashG.(1988)Bacterial septicaema in juvenile tiger shrimp. P. monodonculture in Malaysia brackish water ponds. Asian Fisheries

Sciences2. 9i-lO8.

Anonymous (1994) Shrimp: drought and disease shrinksupply. Review Indonesia (Economic& Business) 128, 37.

Cawthorne D.F.. Beard T. Davenport J. & Wickins J.E (1983)Responses of juvenile Penaeus monodon Fabricius to natural

'and artificial sea waters of low salinity. Aquaculture 32,165-174.

Chakraborti R.K.. Ravichandran P.. Haider D.D.. MandalS.K. & Sanfui D. (1985) Some physico-chemicalcharacteristics of Kakdwip brackishwater ponds and theirinfluence on the survival, growth and production ofPenaeus monodon (Fabricius). Indian Journal of Fisheries 32,224-235.

Chantanachookin C. Boonyaratpalin S.. Kasornchandra J..et al. (1993) Histology and ultrastructure reveal a newgranulosis-like virus in P monodon affected by yellow-headdisease. Diseases of Aquatic Organisms 17.145-157.

Chen J.C. & Chen S.F. (1992) Effects of nitrite on growth andmolting of Penaeus monodon juveniles. ComparativeBiochemistry and Piujsiology C— Comparative PharmacologyandToxicoIogy 101.453-458.

FulksW. &MainK.L. (1992) Diseases of culturedpenaeidshrimpin Asia and Vnited States. Oceanic Institute. Honolulu. HI.375 pp.

Garcia A. & Brune D.E. (1991) Transport limitation of oxygenin shrimp culture ponds. Aquacultural Engineering 10 .269-279.

Hariati A.M.. Wiadnya D.G.R.. Prajitno A.. Sukkel M.. BoonJ.H. & Verdegem M.C.J. (1995) Recent developments ofPenaeus monodon and P. merguiensis culture in East Java.Aquaculture Research 26. 819-829.

Lee D.O.C. & Wickins J.F. (1992) Crustacean Farming. BlackwellScientific Publications. Oxford.

Lin O.K. (1989) Prawn culture in Thailand. What wentwrong.' World Aquaculture 20.19-20.

Millamena CM. (1990) Organic pollution resulting fromexcess feed and metabolite build-up: effect on P. monodonpostlarvae. Aquacultural Engineering 9, 143-150.

Parado-Estepa F.E.D.. Llobrera A.. Villaluz A. & Saldes R.(1993) Survival and metamorphosis of Penaeus monodonlarvae at different salinity levels. Israeli Journal ofAquaculture 45, 3-7.

Sindermann C.J. & Ligbtner D. V. (198 8) Disease Diagnosis andControl in North American Marine Aquaculture: Developmentsin Aquaculture and Fisheries Science. Vol. 17. Elsevier.Amsterdam.

Sunaryanto A. & Mariam A. (1986) Occurrence of apathogenic bacteria causing luminescence in penaeidlarvae in Indonesian hatcheries. Bulletin of theBrackisinvater Aquaculture Development Centre 8. 64-70.

STATISTIX (1985) Statistix Version 4.0 User's Manual.Analytical Software, St Paul. MN.

260 © 1996 Blackwell Science Ltd. .Aguflcu/turefiesearrfi. 27, 255-260