The Use of Mangrove Stands for Shrimp Pond Waste-Water Treatment

lFR.loumal Vol. 7 No.1, 2001

THE USE OF MANGROVE STANDS FOR SHRIMP POND WASTE-WATER TREATMENT

Taufik Ahmad'r, Mohammad Tjarongs"), and Fuad Cholik'r

ABSTRACT

Degraded coastal environmental quality due to mangrove forest conversion is strongly suspected as a cause of the decline of shrimp pond productivity in lndonesia. In addition, the heavy inputs in shrimp culture practices have excessively polluted and enriched the coastal water, which in turn stimulates the growth of pathogenic bacteria. In an effort to prevent further negative effects of shrimp culture practices, experiments were carried out to assess the capability of mangrove stands to reduce pollutants (nitrate, phosphate, total organic matter, and total bacteria) contained in shrimp pond waste-water. Three pond sizes, i.e,5x5, 10x10, and 15x15 m2, three replicates each, planted with Rhizophora mucronata were used as waste-watertreatment ponds. The shrimps (PL-45) were stocked into seven ponds of 500 m2 each, at a density of 20 shrimp/m2. Feed was given 3 times with the total amount 10-3o/o of shrimp biomass per day. Water changes in shrimp ponds were carried out every three days, with 30% of the waste-water channeled into mangrove ponds and held for another three days. The wasle-water was replaced with reservoir water. The water and soil in both shrimp and mangrove ponds as well as in control pond, were sampled every three days prior to water exchange. The NO3-N, PO.-P, TOM concentrations and total bacteria populations were not different among mangrove ponds sizes. NOr-N tended to precipitate, while most of the PO.-P tended to dissolve in water. Total organic miatter (TOM) in mangrove ponds and soil fluctuated at a similar level and pattern with that in shrimp ponds. The population of bacteria in both water and soil of mangrove ponds was slightly lower, even though statistically not significant, than that in shrimp ponds. Thus mangrove stands may have potential for reducing the negative effects of waste-water from shrimp ponds on the environment.

KEYWORDS: mangrove, shrimp pond, waste water treatment

INTRODUCTION and develop sedimentation (Kartawinata et al., 1978) as well as to allow organic matter decomposition Starting from 1980 shrimp culture has developed (Boyd, 1999). The pores or lenticell in stilt roots, es- at a rapid pace, which has brought about a significant pecially in Rhizophora spp., function to exchange gas increase in cultured production. shrimp Unfortunately, allowing the mangrove to grow both in anaerobic and the increase in production was accompanied by dis- aerobic conditions (Notohadiprawiro, 1978; Nontji, tinct conversion of mangrove forest into shrimp ponds. 1984; Soemodiharjo & Soeroyo, 1994). Excessive inputs in shrimp culture and extinction of Atmawidjaja (1987) observed the effect of munici- mangroves in the area in turn enhance the growth of palsewage on a mangrove community pathogenic bacteria which leads to shrimp harvest and concluded that the mangrove community is not harmed by mu- failure. Since 1994, cultured shrimp production has nicipal sewage and to some extent could be used as been decreasing every year and in 199g the produc- an organic waste dumping site. In addition, oysters tion was less than three-quarters of the production in (Crassosfrea rhizophora) 1992. attached on mangrove roots and mangrove cockles (Geloina coaxan) dwelling in Although the ability of mangroves to neutralize the mangrove ecosystem are excellent biofilters for pollutants is not proven, based on their abilities to shrimp ponds (Suharyanto et a\.,1996; Mangampa absorb and use nutrients resulting from decomposing ef a/., 1998; Tjaronge ef a/., 1998) organic wastes for growth (Massaut, gg8), prob- l it is Based on those potentialities, this study aimed at able that mangroves could settle and neutralize waste- assessing the capability of mangrove stands, domi- water, especially organic wastes (Soemodiharjo and nated by Rhizophora mucronata, to neutralize shrimp Soeroyo, 1992). The mangrove root system which is ponds waste-water. Knowledge about the capability commonly dense is able to retain pollutant particles of mangrove stands to neutralize such waste could

1 Researcher at the Research Center of Aquaculture r Researcher at the Research Institute for Coastal Fisheries. Maros

7 Taufik A., M. Tjarongle, and F. Cholik help in the designing an eco-friendly or responsible five stations in each pond, and a sieve was used to coastal aquaculture. separate the molluscs from debris and other organisms. The plankton was sampled using a plankton MATERIALSAND METHODS net no. 25 to filter 100 L water from each ponds. The data of NO3-N, PO4-P, and TOM concentrations as Two-year mang rove stand s, mostly Rh izopho ra old well as total bacteria population of each pond were mucronata, were separated into the only three pond descriptively analysed. The data of each pond were sizes available, i.e. 5x5, 10x10, and 15x15 m2, the computed to obtain the average data for mangrove sizes available with 3 replicates each and 1.0 m high ponds. dykes. The density of mangrove in each pond was not different, nine trees/m2, Two ponds with no man- The shrimp ponds consisted of seven compart- groves were used as settlement ponds or controls. ments (Figure 1), 500 m2each, and were stocked with Each pond was filled with the water flowing from the 20 Pt-451m2. The water in the ponds was maintained shrimp ponds; the water was held for three days prior at90-100 cm depth. A 1-kwh paddlewheelaeratorwas to sampling and then channeled out into the environ- set in each pond. The feed was given at 10% total ment. The water and the bottom soil of the ponds biomass per day in the first month and reduced to 5% were sampled in each pond every 15 days. The soil in the second month and 3% total biomass in the samples for each pond were pooled from five different third month. The amount of feed given was adjusted samples collected using a soil auger until 10 cm based on the estimation on total biomass every 15 depth. The variables observed were NO.-N, PO.-P, total days. The water was changed every three days by organic matter (TOM) concentrations, and the bacte- allowing 30o/o ol the totalvolume to flow out into the rial population as well as benthos and plankton. The mangrove ponds with replacementfrom a reservoir. benthos were sampled using an Eikman's dredge, at !1htt

Resenroii

Oysler (Crassolrea irr#aior) pond 2and3 Seaue€d {Gracillarla sP.) Ponds 4and5 Oii{et cEnal ti'6 Mengrove ponds {5 x 5 ft} g-11 Mmgr*ve ponds {10 x 10 rn} 12"14 Mangrova ponds {15 x t5 m} 15 and 16 : Ccnlrct ponds P and fF Shrirnp pcnds 17 and 18 : Sarpling Fcnds shnmp psrds 'n

Fiqure 1 Experiment pond arrangement based on treatments IFR JournalVol. T No.1, 2001

The reservou (1, 2,3 in Figure) was a 1,S00 m2 mangrove pond sizes were tested in an analysis of pond planted with sea weed (Gracillaria verrucosa) variance. on the bottom and oyster (Crassosfrea iredalei) at28 individuals/m2 set 10 cm above the bottom. The water RESULTSAND DISCUSSION in the reservoirwas pumped out from a deep welland held three days before being allowed to flow into the ln the mangrove ponds, allvariables observed fluc- shrimp ponds (Atmomarsono et al., 1 995). Water and tuated with a tendency to slightly decrease. By the soil from both shrimp ponds (the same two ponds end of the experiment, NO.-N concentrations in the only) and reservoirwere also sampled for NO3-N, POo- water of all ponds, exceptihe 5x5 m2 ponds, were P, TOM concentrations and total bacteria pdpulatioir slightly lower than in the initial concentrations. In the every 15 days. Each shrimp pond sample is expected bottom soil, the concentrations of NO"-N were also to represent a row'of ponds which is assumed to be decreasing and the concentrations in 5x5 m2 ponds homogenous based on the soilquality. were slightly higher than in the rest of the ponds (Fig- ure 2). Statistically, the decreasing rate of NO.-N con- Both NO.-N and PO.-P of water and bottom soil centrations as wellas the initial concentrations were were analysed using spectrophotometer with brucine not significantly different (P<0.05) among pond sulphate and sodium tartrate methods, respectively sizes. (Haryadi et al., 1992). TOM in water was analyzed The concentrations of PO,-P in water decreased using a permanganate titrimetric method and in soil in the first 30 days, but then from day 30 started to as loss on ignition (Melville, 1993). Total bacteria num- fluctuate with a tendency of increasing to the end of bers were estimated from colony counts an TCBSA the experiment. In the bottom soil, PO,-P concentra- (Thiosulfate Citrate Bile Sucrose Agar). The data of tions started to increase 15 days earlier than in wa- each variable were plotted to produce a linear regres- ter. However from day 45 the concentrations kept de- sion, and the slopes of the regression lines among creasing until the end of the experiment (Figure 3).

0.05 0.35 0.3 0.04 -T 3 0.25 o.o3 E; c 0.2 0.15 1- o.o, d 9 0^1 0.01 0.05

0 0 1s 30 45 60 75 90 15 45 60 Dalc Days , --a--5 -+- 10 -*- 15 n* 5 -+- 10 --+- 15 Figure 2 Concentration changes of NO.-N in water (left) and soil (right) of different sizes of mangrove pond

0.4 1.4 1,2 0.3 J J 1 c) E 0.2 E 0.8 (L r 0.6 * TL 0.1 at 0.4 0.2 0 15 30 45 60 75 90 15 30 45 60 75 90 Days Dala __r_5 __r_ 10 _*_ 15 -1-5 --_+_10 +*15 Figure 3. Po4-P concentration changes in water (left) and soil (right) of different sizes of mangrove ponds Taufik A., M. Tjaronge, and F. Cholik

In the settlement orcontrol ponds and in the shrimp No differences were observed in the concentrations of ponds, the behaviour of NO.-N, PO4-P, and TOM con- PO,-P both in water and soil among pond sizes. centrations as well as total bacteria population was Totalorganic matter (TOM) concentration in water similar with that in mangrove ponds. In the case of fluctuated very much, increasing in the first 45 and 60 total bacteria in water and soil, the population was days and then decreasing until the experiment termi- not different among ponds except at the last sam- nated. On the other hand, TOM tended to be more popu- pling (Figure 6). In shrimp ponds, the bacteria stable in the bottom soil (Figure 4). The highest con- and lation in water kept increasing while in mangrove centration in water, 100 ppm, was obtained at day 60 bottom control ponds, it dropped on day 75. In the in 5x5 m2 ponds, a day after heavy rainfall. On the 15 soil, the bacteria population started to increase same day, TOM concentration was the highest in the days earlier than in water. bottom soil of all ponds. Figure 7 shows the changes of TOM concentra- Surprisingly, high TOM contentwas only followed ponds' tions in mangrove, shrimp, and control The by an increase of total bacteria population in water ponds increased in concentrations in the water of all but not in soil. The bacteria population in water started the first 60 days and after that distinctly decreased. to increase on day 45 and exceeded 1.5x103 CFU/ seems to be In the bottom soil, TOM concentration mL at day 75 in 5x5 m2 ponds (Figure 5). In soil' the more stable than in water. bacteria population started to increase at day 60 and In shrimp ponds, the concentration of NO.-N be- reached 30x103 CFU/mL in 10x10 m2 ponds. haved as in both mangrove and control ponds. From

100 14 12 +10 E,60 ctA g c o t* P4 20 2

15 30 45 60 75 90 15 30 45 60 75 90 Dala -.<-5 --r-10 +15 -r* 5 --+- 10 *-',uo"* soil (right) of different sizes of Figure 4. concentrations of total organic matter in water (left) and mangrove ponds

1.5 25 8+(!t 8-(Erl F3 E= 20 Eb 1 r_b 15 He Hp H5 0,5 10 @ glE5 5 0 45 0 15 30 45 60 75 90 Dala Dala a-5 +-10 +15 -a- 5 --r- 10 --+- 15

(right) of different sizes Figure 5. Total bacteria populations (103) in water (left) and bottom soil ofmangrove ponds

10 IFR Joumal Vol. 7 Noj. 2001 the 45th day after the PL were stocked, NO.-N in- of diatomae in shrimp ponds, indicated by watercolour creased but then declined in the last 15 days of the which turned greenish brown, seemed to start absorb- experiment. The addition of feed seemed to tempo- ing PO.-P by day 45 causing the concentration of rarily affect the concentration of NO3-N in shrimp and PO4-P to decline. In mangrove ponds, PO.-P uptake controlponds only (Figure 8). In the bottom soil, NO.- by mangrove vegetation and the associated organ- N concentrations declined in an almost similar pat- isms (Boyd, 1999; Robertson and Phillips, 1995) tern in all ponds. In fact, pond soil acts as a buffer seems to stabilize PO.-P concentration in water 45 which stabilize environmental conditions (Boyd and days after the shrimps were stocked. Massaut, 1998). The reduction of NO.-N concentration in water The inputs, more specifically feed, added to the tended to be higher in mangrove ponds than in either shrimp pond started to affect PO4-P concentration in control or shrimp ponds (Table 1). Mangrove vegeta- mangrove ponds water 15 days earlier than in shrimp tion, plankton and other organisms associated with and control ponds, The highest concentration of POo- the mangrove ecosystem (Table 2) seemed to be the P was observed in shrimp pond water at day 45 after main users of NO.-N. ln shrimp ponds, the addition of the shrimps were stocked (Figure 9). A dense growth feed at 1.5 kg/500 m2 produced less NO"-N than the

J^25 2.5 E d20 €-(!; t o x> o Ed 15 =15c 'r6(U^ .9 (l)r fixl 4 *10 o (D o- 0.5 .q5 I(J 0 EO 45 60 75 90 0153045607590 Da)s Days Shrimp o Shrimp -a-Mangrow -+Control o --1-Mangrove -FControl

Figure 6. Average population of bacteria in water (left) and soil (right) of shrimp, mangrove and control oonds

14 12 60 a50 10 €oo EB ;6 F30 I 20 4 10

15 90 15 75 90 Dala Dala o Shrimp -r-Mangrov€ --+-Control o Shrimp -a-Mangrov€ -+Control

Figure 7 TOM concentrations in water (left)and soil (right) of shrimp, mangrove and control ponds

11 Taufik A., M. Tiaronge, and F. Cholik

0.05 0.35 0.3 0.04 0.25 J J p 0.03 c EP o.2 z z 0.15 A 0.02 A z z. 0.1 0.01 0.05 0 0 45 60 75 90 1'5 30 15 30 45 TC Days Dala o- ShrimP --r* Mangrov€ *- Control -1- Shrimp -a- Mangrove ---1-- Control

Figure 8 NO3-N concentrations in water (left) and soil (right) of shrimp, mangrove, and control ponds

1.4 0.5 0.45 1.2 0.4 0.35 ^ J S 0.3 ot I o.25 e + + 0.6 A ^) p E 0.15 o.4 0.1 o.2 0.05 0 0 15 30 45 60 tB.rfo 15 30 45 60 75 90 Days Shrimp Mangrov€ --*- Control o Shrimp -1-Mangrov€ -*-Control a- --r-

Figure 9. PO"-P concentrations in water (left) and soil (right) of shrimp, mangrove and control ponds

amount used by phytoplankton (Figure 10). Nitrifica- water up to0.47 mg/l by day 45^ Then, the concentration seems to occur intensively due to the thorough tion started to decrease and reached 0.22 mg/l by dissolved oxygen distribution in the water column day 90. The changes in feed input, 10% of total biom- reaching the pond bottom. The light brown color of ass in the first month, 5% in the second month, and pond bottom soil indicated no anaerobic condition in 3% in the third month are suspected to be the main the pond (Boyd ef a1.,1994). cause. In the first month, the shrimp were so small Consequently, in The concentration of PO.-P slightly increased in that not all the feed was consumed. of the feed decomposed into mangrove, shrimp and control ponds. Based on the r the first 45 days, most phosphate, nitrate, and values in a linear regression, the change of PO'-P inorganic compounds such as ammonia which then was more predictablethan NO.-N concentrations. Even ammonia as well as unionized mangrove ponds. In the though the concentration of PO.-P was high compared flowed into both controland were better able to naturalwater (Boyd, 1979), the ratio of NO.-N to second and third months, the shrimp which reduced the PO.-P was below that which would encourage to take and consume the feed, Boyd (1979) and eutrophication due to NO3-N limitation. Bloom of plank- amount of unconsumed feed. main sources ton as a result of eutrophication usually occurs at a Poemomo (1 988) reported that one of the ponds feed. N-P ratio more than 10 (Ahmad ef a/., 1998). of phosphate in shrimp is artificial were The addition of inputs in terms of artificial feed in- The changes of TOM in a linear regression pond' creased the concentration of PO4-P in shrimp pond more unpredictable, especially in the control

12 IFR,lournal Vol. 7 No.l. 2001

Table 1. Regression values of various water quality variables in shrimp, mangrove and control ponds

Regression parameters Variable Pond

NO3-N (mg/L) Shrimp 0.0314 -0.00000 -0.314',1 Mangrore 0.0694 -0.00006 -0.4925 Control 0.0368 -0.00001 -0.6928 PO4-P (mg/L) Shrimp 0.0763 0.00028 0.5444 Mangrow 0.042 0.00029 0.8067 Control 0.066 0.00026 0.7199 TOM (mg/L) Shrimp 24.0712 0.2139 0.388 Mangrow 21.4716 0.26886 0.4434 Control 16.6623 0.49383 0.6933 Bacteria (103 Shrimp 0.3756 0.0161 0.7185 CFU/mL) Mangrow -0.054 0.0115 0.791 5 Control -0.007 0.0237 0.562

Table2. Macro benthos and plankton qualitatively identified in the experiment ponds

Pond Benthos Plankton

Mangrow Ceithidea, Littoina, Amphora, Oscillatoia, Nitzschia, Acartia, Tellina, Cmssosfrea, Brachionus, Pleurcsigma, Biddulphia, Anabaena, Nenfopsls Surirellea, Calotix

Shrimp Ceithidea, Littoina B rac h io n us, O sc i I I atoi a, A c a rt i a, P I eu rcs ig m a, Anabaena, Nitzschia, Amphora, Suirellea, Chaetoceros, B iddulphia Control Ceithidea, Littoina Oscillatoia, Brachionus, Acaftia, Nitzschia,

Am phora, P leuros igm a, S u i rel I ea

Air Water

r. Plants +T ruoa

Figure 10. The cycle of nitrogen in ponds (after Boyd, 1991) compared to those of PO,-P concentration. lt seems than in controland mangrove ponds. Sedimentation that more organic matter accumulated in control pond in three days without addition of input and also tannin than in both mangrove and shrimp ponds. The increase contained in mangrove litterwere suspected to inhibit in TOM concentration followed by the increase of bac- the growth of bacteria in water (Atmomarsono ef a/.. teria population was more observable in shrimp ponds 1995; Harahap, 1997).

13 Taufik A., M. Tjaronge, and F. Cholik

The behavior of NO.-N, PO4-P, and TOM concen- Based on the findings above, mangrove stands trations and bacteria populations in pond bottom soil have potential for shrimp ponds waste-water treatment. was more or less similar with those in water even Further, they could be used in an ecofriendly recircu- though the changes were more unpredictable, except lating shrimp culture system. Ahmad (1988), reported for the bacteria population (Table 3). Ahmad (1998) thatthe maximum area of mangroveforestwhich could observed similar patterns of NO.-N and PO.-P changes be converted into productive shrimp ponds is less than in mangrove stands for almost two years. In shrimp 20o/o ol the total area based on salinity distribution, pond bottom soil, the growth of the bacteria popula- amplitude of tide, soil quality and texture, as well as tion was more than twice that in mangrove pond bot- land elevation, However, more in-depth study on the tom soil. The litter (leaves and branches) of mangrove organisms associated with the mangrove ecosystem containing tannin (Soqtarno, 1997) is suspected to or the active substances contained in mangrove trees inhibit the growth of bacteria populations (Table 4) in should be carried out to assure the optimal use of both water or pond bottoms. mangrove stands in shrimp culture.

Table 3. The regression values of various variables in shrimp, mangrove, and control ponds soil Regression parameters Variable Pond

NO3-N (mg/L) Shrimp 0.2291 - 0.00004 - 0.1318 Mangrore 0.2735 - 0.00014 - 0.7061 Control 0.2568 - 0.00012 - 0.6282 Po4-P (mg/L) Shrimp 0.5545 - 0.00011 - 0.1208 Mangrore 0.6771 - 0.00011 - 0.1018 Control 0.6411 0.00037 0.3741 TOM (mg/L) Shrimp 7.604 - 0.0043 0.0851 Mangrow 8.2088 0.5238 0.1 529 Control 8.6772 0.00047 0.14038 Bacteria (1000 CFU/mL) Shrimp - 6.358 0.2501 0.8718 Mangrore - 3.042 0.1683 0.6984 Control - 5.652 0.2613 0.7072

Table4 Vibrios identified in the experiment ponds Ponds Water Soil

Mangrore Vibio campbellii, V. leiognathi, Vibio metschnikovi, V. harueyii, V. splendidus, V. harueyii, V. cholene, V. mimicus, V. cholerce, V. alginolitycus, V. tubiashi, V. metschnikovi, V. V. campbellii, V. tubiashi, cholerae, V. odalli, V. alginoliticus, V. panhaemoliticus, P. anguillarum, V. harueyii, V. natiegens V. natriegens, V. splendidus, V. fischeri Shrimp Vibio mimicus, V. alginolitycus, V, mimicus, V. cholerae, metschnikovi, V. cholene, V. splendidus, V. splendidus V. metschnikovi, V. fischeri

Control V. mimicus, V. tubiashi, V. campbelli, V. mimicus, V. cholerae, V. leiagnathi, V. alginolitycus, V. fischei, V. harueyii V. leiognathi, V. cholene, V. odalli, V. harveyii

14 IFR Joumal Vol. 7 No.l, 2001

coNcLUstoNs Harahap, F. 1997. Chemical analysis in n-hexane and benzene fraction of mangrove, Rhizophora mucro- The use of mangroves for shrimp ponds waste- nata Lamk, bark. Master of Science Thesis. Hasa- water treatment is promising for reducing the possi- nuddin University, Ujung Pandang, Indonesia.6g pp. bility of eutrophication, which is usually followed by Haryadi, S., l.N.M. Suryadiputra, and B. Widigdo, 1992. disease out-breaks caused by organic pollution gen- Practical quidence on water quality analysis. Faculty erated in shrimp ponds. Further in-depth study on the of Fisheries, Bogor Agricultural university, Indonesia. organisms associated with the mangrove ecosystem 55 pp. for shrimp ponds bioremediation is recommended. Kartawinata, K.S., S. Adisoemarto, S. Soemadihardjo, and l.G.M. Tantra. 1978. The status of the knowledge ACKNOWLEDGEMENTS on mangrove forest in Indonesia /n Soemodiharjo, S., A. Nontji, and A. Jamali. Proceedings of the Semi- The research was funded by the Governmentof In- nar on Mangrove Forest Ecosystem, Jakarta 27 Feb- donesia through the Agricultural Development project ruary-1 March 1978. MAB Indonesia and Llpl. Jakarta. p.21-40. FY 1999/2000. Three submersible pumps and a water quality checkerwere provided by Japan International Mangampa,M,, M. Tjaronge, and S. Tahe. 199g. The effect of depth arrangement (Crassosfrea Research Center for Agricultural Sciences through a of oyster irredalei) as biofilter in intensive shrimp pond reser- collaboration project on nutrient cycling in the coastal voir. Research Report, Research Institute for Coastal area of Indonesia. The hard work of researchers, tech- Fisheries, Fy 1999/2000. 9 pp. nicians, and a typist in supporting the research and Massaut, L. 1998. Mangrove management and shrimp preparing the manuscript is highly appreciated. aquaculture. 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