6. ZWD performance in shrimp and prawn cultivation

Commodities used in this ZWD system were white shrimp (L. vannamei) and giant freshwater prawn (M. rosenbergii De Mann). The ZWD system was examined in pilot scale for both commodities, but the system was only applied in white shrimp at industrial scale. Here are the detailed explanations of each performance.

#### 6.1. White shrimp cultivation

#### 6.1.1. Pilot scale

Research on the performance of ZWD system on white shrimp nursery at pilot scale has been done [13]. The ZWD system was compared to batch system as control based on performances of water quality and biological parameters in the same stocking density (approx. 400 ind/m3 ). Microbial components used were nitrifying bacteria consortia (Nitrosomonas sp. and Nitrobacter sp.) and microalgae C. calcitrans.

After 90 days culture period, all growth performance including average body weight, total biomass, survival rate, and specific growth rate was significantly higher in ZWD than those of batch systems (Table 4). In contrast, food conversion ratio in ZWD system was significantly lower than that of conventional culture system (1.27 and 4.10, respectively). Based on data, the FCR value of ZWD system was still tolerance range of shrimp (1.5–2.6).


Table 4. Biological performance during 90-day cultivation period [13].

Water quality during 90-day cultivation period was still in tolerance levels for white shrimp in both systems, as seen in Table 5. As a concern, threshold value of ammonium in ZWD systems was higher than batch system, it was 0.69 ppm compared to 0.59 ppm, but it was not significantly different (p > 0.05). High ammonium level was caused by higher feed input in the ZWD system, it was about 44% compared to the batch system. A large feed input would affect the increment of ammonium level in culture, but ZWD system has rapid ammonium breakdown capacity that was accomplished through microbial manipulation. Moreover, nitrite level also did not differ significantly in both systems. These levels suggested that the ammonium and nitrite breakdown capacity of ZWD systems are higher than batch system. In addition, better ammonium and nitrite breakdown capacity were shown through nitrate level that was higher in ZWD system after 90-day culture period. The nitrate level in ZWD system reached 42.9 mg/L, while in batch system, it was 14.17 mg/L.

Besides the benefits of nitrifying bacteria and microalgae in maintaining water quality, they also indirectly inhibit pathogenic bacteria Vibrio spp. growth. Microbiological assessment shown that excessive organic matter did not increase the number of Vibrio spp. Previous research reported that marine diatom, such as C. calcitrans, has the ability to secrete fatty acids and esters, antibacterial compounds which inhibit several heterotrophic bacteria growth, such as Vibrio spp. [74]. Another analysis of predominant bacteria found in shrimp cultivation using ZWD system reported that the water contained following species, based on the most dominant bacteria found B. flexus, Geobacillus stearothermophilus, five species of Bacillus sp., Pseudomonas oleovorans, Pseudomonas peli, and Xenorhabdus nematophilus [66]. Bacillus sp. known as probiotic bacteria suggested that ZWD system not only achieved acceptable psychochemical parameters, but also microbiological parameters support shrimp growth as well.

#### 6.1.2. Industrial scale

Wt <sup>¼</sup> <sup>X</sup><sup>n</sup> i¼1

e. Food conversion ratio (FCR) indicates a ratio of efficiency of feed, which is converted into

FCR <sup>¼</sup> Total feed given during culture period kg ð Þ

Commodities used in this ZWD system were white shrimp (L. vannamei) and giant freshwater prawn (M. rosenbergii De Mann). The ZWD system was examined in pilot scale for both commodities, but the system was only applied in white shrimp at industrial scale. Here are

Research on the performance of ZWD system on white shrimp nursery at pilot scale has been done [13]. The ZWD system was compared to batch system as control based on performances of water

components used were nitrifying bacteria consortia (Nitrosomonas sp. and Nitrobacter sp.) and

After 90 days culture period, all growth performance including average body weight, total biomass, survival rate, and specific growth rate was significantly higher in ZWD than those of batch systems (Table 4). In contrast, food conversion ratio in ZWD system was significantly lower than that of conventional culture system (1.27 and 4.10, respectively). Based on data, the

quality and biological parameters in the same stocking density (approx. 400 ind/m3

FCR value of ZWD system was still tolerance range of shrimp (1.5–2.6).

Table 4. Biological performance during 90-day cultivation period [13].

Parameter Batch ZWD Final ABW (g) 5.45 � 0.28 8.24 � 0.84\* SR (%) 27.22 � 2.09 90.82 � 2.5\* Total biomass (g) 160.48 � 6.62 923.38 � 42.15\* SGR (%) 7.24 � 0.05 7.7 � 0.11\* FCR 4.10 � 0.66 1.27 � 0.29\*

Where, Wt = total biomass (gr), Wi = body weight of the i-th shrimp (gr)

animal body mass. FCR was calculated as follow:

the detailed explanations of each performance.

6.1. White shrimp cultivation

6.1.1. Pilot scale

312 Biological Resources of Water

\*

microalgae C. calcitrans.

Significant difference p < 0.05.

6. ZWD performance in shrimp and prawn cultivation

Wi (5)

Total biomass kg ð Þ (6)

). Microbial

Research conducted for grow out white shrimp cultivation using ZWD system at industrial scale has been applied in UD. Populer, Gresik, East Java [50]. The research used PL-17 white shrimp as cultured animal at low salinity water (5 ppt) in ZWD system. Culture period was 70 days for three different stocking densities; there were 200, 300, and 400 ind/m<sup>3</sup> further referred as SD200, SD300, and SD400.


Table 5. Water quality measurement during 70-day culture period [13].

Based on the research, biological parameters have been documented as shown in Table 6. Interestingly, survival rate has a value inversely to total biomass. Treatment SD400 has the lowest survival rate of 70.59 � 6.15% but has the highest total biomass, which is 44.13 � 4.44 kg. It was because in higher stocking density has a higher stress level than lower density culture, such as space competition, higher cannibalism level, etc. If the total number of living individuals was calculated, SD400 has the largest number of about 280 individuals, and this number was larger than SD200 and SD300, which were 186 and 237 individuals, respectively. In addition, given feed was the highest proportion compared to other two treatments, so that nutrient sources were greater too, it can be seen from its size distribution, SD400 has a size of 100–150 ind/kg of 95.85%. Specific growth rate and FCR did not differ significantly. Based on the value of productivity, three treatments have reasonable value for cultivation conducted in Indonesia that was 1.72–2.0 kg /m3 for 100–120 days of culture on stocking density of 60–300 ind/m3 .

For water quality parameters, all parameters had acceptable tolerance limits. Among all treatments, there was no significantly difference (p > 0.05). Table 7 showed the measurements for water quality for 70 days of culture period.

treatments in the system were differences in the number of bamboo shelters installed in culture tank (2 x 1 x 0.4 m) and variation of stocking density. There were no shelter as control (C), two shelters (20% of water volume) (CB1), and four shelters (40% of water volume) (CB2) (Figure 6). Stocking density in sheltered tank was two times higher than control, and it was 60 ind/m2

Parameter SD200 SD300 SD400 Tolerance range

Closed Aquaculture System: Zero Water Discharge for Shrimp and Prawn Farming in Indonesia

http://dx.doi.org/10.5772/intechopen.70944

<sup>4</sup> (mg/L) 0–0.5 0–3.0 0–0.30 < 3.95 mg/L

<sup>2</sup> (mg/L) 0–5.0 0.2–3.0 0.2–5.0 < 25.7 mg/L

<sup>3</sup> (mg/L) 5.0–35.0 5.0–30.0 5.0–25.0 < 200 mg/L

Temperature (�C) 29.3–30.1 29.8–30.1 30.4–30.9 25–32�C pH 7.61–8.27 7.71–8.36 7.27–8.38 4–9.5 DO (mg/L) 4.90–8.50 5.00–8.00 5.60–7.80 > 4 mg/L

At the end of cultivation period, growth performance of prawns with shelters has better performance than control (no shelter). Treatment of CB2 produced final total biomass of 196 � 0.09 gr, specific growth rate of 8.24% gr/day, final mean body weight of 2.17 � 0.89 gr, and final mean body length of 6.50 + 0.91 cm. Shelter installment also resulted in a significant higher survival rate that was significantly different to control, as seen in Table 8. It was due to the availability of a larger territory area, vertically and horizontally, which will reduce contact possibility of prawns that was reared at high stocking densities, and at minimum contact with each other, cannibalistic behavior was suppressed. In addition, culture productivity increased with system using shelter, both CB1 and CB2 (30 and 39%, respectively). This suggests that shelters installation with the

Based on water quality parameters, ZWD system balances dissolved nitrogen concentration in water during cultivation period. pH value, dissolved oxygen (DO), ammonium nitrogen (NH<sup>þ</sup>

Figure 6. Cubical-bamboo used as shelters (left); cultivation scheme for prawn cultivation using bamboo shelters (right) [51].

addition of microbial consortium improves prawn cultivation productivity.

The cultivation was conducted for 28 days.

Table 7. Water quality measurement during 70-day culture period [50].

NH<sup>þ</sup>

NO�

NO�

.

315

4 ),

#### 6.2. Prawn cultivation

The performance of ZWD system on the nursery phase and grow-out phase of giant freshwater prawn (M. rosenbergii De Mann) was evaluated using addition of two types of shelters: three-dimensional cubical bamboo shelters (on nursery phase experiment) [51] and vertical textile shelters (on grow-out phase experiment) [11].

#### 6.2.1. ZWD system and additional bamboo shelters

Research was conducted at laboratory scale using PL40 giant freshwater prawn taken from commercial hatchery in Sukamandi, West Java [51]. Microbial components used were nitrifying bacteria and Chlorella sp. that inhabit in freshwater. The research used ZWD system with addition of cubical bamboo shelter that has dimension of 0.6 x 0.6 x 0.2 m. Experimented


Table 6. Biological parameter measurement during 70-day culture period [50].

Closed Aquaculture System: Zero Water Discharge for Shrimp and Prawn Farming in Indonesia http://dx.doi.org/10.5772/intechopen.70944 315


Table 7. Water quality measurement during 70-day culture period [50].

Based on the research, biological parameters have been documented as shown in Table 6. Interestingly, survival rate has a value inversely to total biomass. Treatment SD400 has the lowest survival rate of 70.59 � 6.15% but has the highest total biomass, which is 44.13 � 4.44 kg. It was because in higher stocking density has a higher stress level than lower density culture, such as space competition, higher cannibalism level, etc. If the total number of living individuals was calculated, SD400 has the largest number of about 280 individuals, and this number was larger than SD200 and SD300, which were 186 and 237 individuals, respectively. In addition, given feed was the highest proportion compared to other two treatments, so that nutrient sources were greater too, it can be seen from its size distribution, SD400 has a size of 100–150 ind/kg of 95.85%. Specific growth rate and FCR did not differ significantly. Based on the value of productivity, three treatments have reasonable value for cultivation conducted in Indonesia that was

For water quality parameters, all parameters had acceptable tolerance limits. Among all treatments, there was no significantly difference (p > 0.05). Table 7 showed the measurements for

The performance of ZWD system on the nursery phase and grow-out phase of giant freshwater prawn (M. rosenbergii De Mann) was evaluated using addition of two types of shelters: three-dimensional cubical bamboo shelters (on nursery phase experiment) [51] and vertical

Research was conducted at laboratory scale using PL40 giant freshwater prawn taken from commercial hatchery in Sukamandi, West Java [51]. Microbial components used were nitrifying bacteria and Chlorella sp. that inhabit in freshwater. The research used ZWD system with addition of cubical bamboo shelter that has dimension of 0.6 x 0.6 x 0.2 m. Experimented

SR (%) 93.52 � 3.32<sup>a</sup> 79.11 � 5.81b 70.59 � 6.15b SGR (%) 4.64 � 0.14a 4.22 � 0.24<sup>a</sup> 4.40 � 0.25<sup>a</sup> FCR 1.05 � 0.07a 1.06 � 0.08<sup>a</sup> 1.14 � 0.14<sup>a</sup> Total biomass (kg) 27.7 � 1.55a 36.25 � 3.01b 44.13 � 4.44c Size distribution (%) 100–150 ind/kg 86.77<sup>a</sup> 91.93ab 95.85<sup>b</sup>

150–250 ind/kg 13.23<sup>a</sup> 8.07ab 4.15<sup>b</sup>

) 1.39 1.81 2.21

)

200 300 400

.

1.72–2.0 kg /m3 for 100–120 days of culture on stocking density of 60–300 ind/m3

water quality for 70 days of culture period.

textile shelters (on grow-out phase experiment) [11].

Parameters Stocking Densities (ind/m<sup>3</sup>

Note: Means of values with same superscript along rows are significantly different (p < 0.05).

Table 6. Biological parameter measurement during 70-day culture period [50].

6.2.1. ZWD system and additional bamboo shelters

6.2. Prawn cultivation

314 Biological Resources of Water

Productivity (kg/m<sup>3</sup>

treatments in the system were differences in the number of bamboo shelters installed in culture tank (2 x 1 x 0.4 m) and variation of stocking density. There were no shelter as control (C), two shelters (20% of water volume) (CB1), and four shelters (40% of water volume) (CB2) (Figure 6). Stocking density in sheltered tank was two times higher than control, and it was 60 ind/m2 . The cultivation was conducted for 28 days.

At the end of cultivation period, growth performance of prawns with shelters has better performance than control (no shelter). Treatment of CB2 produced final total biomass of 196 � 0.09 gr, specific growth rate of 8.24% gr/day, final mean body weight of 2.17 � 0.89 gr, and final mean body length of 6.50 + 0.91 cm. Shelter installment also resulted in a significant higher survival rate that was significantly different to control, as seen in Table 8. It was due to the availability of a larger territory area, vertically and horizontally, which will reduce contact possibility of prawns that was reared at high stocking densities, and at minimum contact with each other, cannibalistic behavior was suppressed. In addition, culture productivity increased with system using shelter, both CB1 and CB2 (30 and 39%, respectively). This suggests that shelters installation with the addition of microbial consortium improves prawn cultivation productivity.

Based on water quality parameters, ZWD system balances dissolved nitrogen concentration in water during cultivation period. pH value, dissolved oxygen (DO), ammonium nitrogen (NH<sup>þ</sup> 4 ),

Figure 6. Cubical-bamboo used as shelters (left); cultivation scheme for prawn cultivation using bamboo shelters (right) [51].


Ammonium concentration during cultivation was maintained acceptable for prawn culture. On early stage of cultivation period, ammonium reached to almost undetectable level but gradually increased to 0.09–0.12 mg/L, observed in all treatments. The highest ammonium

Closed Aquaculture System: Zero Water Discharge for Shrimp and Prawn Farming in Indonesia

respectively by the lower stocking densities (Table 11). Nitrite concentration during cultivation remained below the tolerance limit of freshwater prawn (1 mg/L). Nitrite concentration was gradually decreased during the cultivation from 0.064–0.066 mg/L to 0.015–0.032 mg/L in all treatments, showing nitrification process of conversion of nitrite to nitrate. Nitrate concentration remained stable between 53.9–71.0 mg/L in all treatments. Overall, DO levels during

), followed

317

http://dx.doi.org/10.5772/intechopen.70944

concentration (0.12 mg/L) was obtained in the highest stocking density (60 ind/m2

Figure 7. Cultivation scheme for prawn cultivation on grow-out phase using vertical textile shelters [11].

)

Mean body weight (g) 11.37 � 4.96 9.34 � 3.82 10.80 � 5.62 10.98 � 5.86 11.46 � 4.52 SGR (% per day) 2.569 1.393 2.105 1.916 1.893 Survival rate (%) 78.3 76.3 70.0 70.0 67.1 Total biomass (g) 534.48 532.57 734.06 922.3 974.37 Total feed (g) 526.75 625.87 864.49 1080.5 1334.14 Feed conversion ratio (FCR) 0.99 1.18 1.18 1.17 1.37

30 40 50 60 70

Parameters Treatment (ind/m2

Table 10. Prawn growth performance during 60-day cultivation period [11].

Table 8. Growth performance during 28-day cultivation period [51].

nitrite nitrogen (NO� <sup>2</sup> ), and nitrate nitrogen (NO� <sup>3</sup> ) remain stable during the culture period, keeping it in tolerance range of prawns (Table 9).

#### 6.2.2. ZWD system and additional textile vertical substrate

Prawn (M. rosenbergii De Man) cultivation on the grow-out phase takes a period of 60 days, longer than nursery phase, which is only 14 days. For longer period of water quality maintenance, several inoculation of nitrifying bacteria suspension (105 CFU/mL) was needed. Prawn cultivation was conducted using five different stocking densities: 30, 40, 50, 60, 70 ind/m<sup>2</sup> into each pond (2 x 1 m2 ) [11]. Shelter used in this research was textile vertical substrate that was placed in culture tank as seen in Figure 7.

Bodyweight, body length, specific growth rate, and survival rate were measured during 60 day cultivation (Table 10). As stocking density increases, prawn growth rate and survival rate decrease, due to competition of resources and risk of cannibalism. In final measurement, the highest mean bodyweight and body length were achieved by 70 ind/m2 stocking density (11.46 � 4.52 g and 10.70 � 1.50 cm, respectively). Specific growth rate and survival rate from all treatments range between 1.393–2.569%/day and 67.1–76.3%, respectively. Overall, biological performance did not differ significantly among other stocking densities (p > 0.05).

From these results, the presence of a microbial component in rearing tank, mostly attached on solids, such as CaCO3, and the textile vertical substrate surface directly improves water quality. In addition, textile vertical shelters reduce aggressive behavior of prawns due to secured spaces for each individual.


Table 9. Water quality parameter during 28-day cultivation period [51].

Ammonium concentration during cultivation was maintained acceptable for prawn culture. On early stage of cultivation period, ammonium reached to almost undetectable level but gradually increased to 0.09–0.12 mg/L, observed in all treatments. The highest ammonium concentration (0.12 mg/L) was obtained in the highest stocking density (60 ind/m2 ), followed respectively by the lower stocking densities (Table 11). Nitrite concentration during cultivation remained below the tolerance limit of freshwater prawn (1 mg/L). Nitrite concentration was gradually decreased during the cultivation from 0.064–0.066 mg/L to 0.015–0.032 mg/L in all treatments, showing nitrification process of conversion of nitrite to nitrate. Nitrate concentration remained stable between 53.9–71.0 mg/L in all treatments. Overall, DO levels during

Figure 7. Cultivation scheme for prawn cultivation on grow-out phase using vertical textile shelters [11].


Table 10. Prawn growth performance during 60-day cultivation period [11].

nitrite nitrogen (NO�

316 Biological Resources of Water

each pond (2 x 1 m2

(p > 0.05).

NH<sup>þ</sup>

NO�

NO�

spaces for each individual.

<sup>2</sup> ), and nitrate nitrogen (NO�

Note: Different letters in the same column denote a significant difference (p < 0.05).

Prawn (M. rosenbergii De Man) cultivation on the grow-out phase takes a period of 60 days, longer than nursery phase, which is only 14 days. For longer period of water quality maintenance, several inoculation of nitrifying bacteria suspension (105 CFU/mL) was needed. Prawn cultivation was conducted using five different stocking densities: 30, 40, 50, 60, 70 ind/m<sup>2</sup> into

Parameters Control CB1 CB2

Total biomass (gr) <sup>141</sup> � 0.03a <sup>183</sup> � 0.05b <sup>196</sup> � 0.09b SGR (gr/day) 7.74 7.88 8.24 Survival rates (%) 77 90 92 Productivity increase compared to control (%) — 30 39

Bodyweight, body length, specific growth rate, and survival rate were measured during 60 day cultivation (Table 10). As stocking density increases, prawn growth rate and survival rate decrease, due to competition of resources and risk of cannibalism. In final measurement, the highest mean bodyweight and body length were achieved by 70 ind/m2 stocking density (11.46 � 4.52 g and 10.70 � 1.50 cm, respectively). Specific growth rate and survival rate from all treatments range between 1.393–2.569%/day and 67.1–76.3%, respectively. Overall, biological performance did not differ significantly among other stocking densities

From these results, the presence of a microbial component in rearing tank, mostly attached on solids, such as CaCO3, and the textile vertical substrate surface directly improves water quality. In addition, textile vertical shelters reduce aggressive behavior of prawns due to secured

<sup>4</sup> (mg/L) 0.041–0.121 0.033–0.022 0.044–0.116

<sup>2</sup> (mg/L) 0.011–0.156 0.012–0.237 0.011–0.210

<sup>3</sup> (mg/L) 13.33–53.22 5.00–44.97 8.33–37.491

Parameters Control CB1 CB2 pH 7.47–8.45 7.40–8.07 7.13–7.96 DO (mg/L) 6.43–8.10 6.37–747 5.87–7.63

Table 9. Water quality parameter during 28-day cultivation period [51].

) [11]. Shelter used in this research was textile vertical substrate that was

keeping it in tolerance range of prawns (Table 9).

placed in culture tank as seen in Figure 7.

6.2.2. ZWD system and additional textile vertical substrate

Table 8. Growth performance during 28-day cultivation period [51].

<sup>3</sup> ) remain stable during the culture period,


Research in technical feasibility has been conducted in white shrimp culture using ZWD system at grow-out stage. Based on criteria, north coastal areas of East Java Province are suitable for white shrimp urban aquaculture using ZWD system, such as Tuban, Lamongan, Gresik, Sidoarjo, Pasuruan, Probolinggo, and Situbondo, etc. The sites were included in the

Closed Aquaculture System: Zero Water Discharge for Shrimp and Prawn Farming in Indonesia

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• Environmental condition is suitable for shrimp growth such as temperature and humidity

• Land topography is included into lowland making it possible to construct shrimp farming • The sites are close to domestic market in Surabaya as capital cities of East Java province and Lamongan that had many cold storage companies (19.8%) and fish processing units

The economic feasibility was analyzed to calculate the overall cost and profitability from real implementation of ZWD system at industrial scale in Gresik (East Java, Indonesia) [50]. White shrimp juveniles were stocked on different stocking densities, providing that varying stocking densities can affect financial calculation, considering operational as well as investment expenses. Assumptions used were to produce 1000 kg shrimp/cycle during 10 years production period. The results showed that the best biological feasibility was in stocking density at 400 ind/m3

needed the least area to produce 1000 kg/cycle. So, this economic feasibility takes the best

feed, labor, electricity, seawater, algae and probiotics, chemical and disinfectants, harvesting, packaging and delivery, and depreciation costs that has the proportion as seen in Figure 8. The operation cost at 400 ind/m3 reached Rp 44,227,125, while the highest component contributions to the investment costs were production ponds cost (36–42%) and land purchasing (21–24%)

Financial projections were calculated to predict the break event point. Profit could be calculated by subtracting the total revenue with production cost. Assumed that there were four production cycles per year, in which 1000 kg shrimps were produced per cycle with duration of 3 months, in 1 year, the farm would produce 4000 kg of fresh shrimp with total revenue Rp 240,000,000. The production cost in 400 ind/m3 stocking density was achieved Rp 40,227,125 per cycle or Rp 160,908,500 per year and has the highest profit Rp 79,091,500 among all stocking density treatment. A total of 400 ind/m3 stocking densities treatment will achieve a

To assess the economic feasibility of ZWD system, financial ratios were calculated. Financial ratio analyzed consisted of NPV, IRR, B/C ratio, and Pay Back Period (PBP). Based on financial

. Based on calculation, operational cost consisted of shrimp seeds,

The lowest operational and investment cost was stocking density at 400 ind/m3

.

319

, because it

• Geographically, the sites are adjacent to the sea, therefore easy to get seawater

ranged between 22 and 34C and 50–86%, respectively

(23.7%) compared to total available units in Indonesia

• There is no social conflict of interest

7.2. Economic feasibility analysis

performance in 400 ind/m3

and total cost reached Rp 318,230,000.

payback period after 4 years of operation.

following criteria:

Table 11. Water quality parameters during 60-day cultivation period [11].

cultivation remained within tolerance range of prawn (min. DO is 4 mg/L) [44]. DO level decreased with response to increasing prawn growth, and the lowest level was 3.7 mg/L in 70 ind/m<sup>2</sup> . pH level was relatively the same among all treatments, ranged between 7.71–7.96. From these parameters, it can be concluded that water quality during cultivation is suitable for the grow-out phase of prawns.

Based on microbiological parameters, there was a significant difference in microbial diversity between batch and ZWD system. In batch system, the water contained various species during cultivation period such as Xenorhabdus japonica, Bacillus megaterium, Micrococcus luteus, and Bacillus amyloliquefaciens, whereas in ZWD system, B. megaterium dominated from second week to the end of cultivation period. Batch system showed a fluctuation on bacterial dominance, which probably due to various abiotic and biotic factors, and therefore, tanks were prone to pathogen infection. In contrast with ZWD system, B. megaterium, which has been proven to benefits prawn growth, constantly dominated water during cultivation. Its dominance limited other bacteria domination, including pathogenic bacteria as well. Total pathogen bacteria particularly Vibrio spp. was counted. Vibrio spp. in rearing tank reached 100 –103 CFU/mL during cultivation in both systems. Based on the results, Vibrio spp. abundancy below 106 CFU/mL was safe for prawn [69].

It was proven that the use of nitrifying bacteria can maintain good water quality, and textile vertical substrate can support a higher stocking density, better growth, larval survival rate, and profit of prawn M. rosenbergii de Man during the grow-out phase.
