Brackish Water Ponds Research Articles

Predators effects on mortality of sandfish Holothuria scabra cultured in multitrophic system

Sandfish Holothuria scabra is a species of high economic value that causes sandfish to be the most captured sea cucumber species, and is an important source of income for fishermen in coastal villages. Sandfish capture causes already over fishing. If the wild population of sandfish is not managed properly, over fishing could cause sandfish extinction. This reason, an alternative efforts are needed to increase sandfish production, such as cultivation and restocking. Sandfish was a species that can live in the estuary region, so that it has the potential to be maintained in brackish water ponds. One of the problems of Sandfish cultivation in the brackish water ponds was the predators attack. This study aims to analyze the predator attack on sandfish. The study was carried out on a microcosm scale by using the tanks. The organism used was Sandfish H. scabra, Nile Tilapia Oreochromis niloticus, and seaweed Gracilaria sp. Mangrove Snail attack can cause death if the sandfish has already eviscerated. The healing process takes one to several weeks, depending on the size of the wound. Nile Tilapia attacks were generally not deadly. Death only occurs if the wound is too deep and causes internal organs to come out, but this was very rare. During the study, only one case occurred in which the sandfish died due to the attack of Nile Tilapia. The sandfish that not injured in the ventral side, and does not suffer from evisceration, the mortality was zero. Sandfish wounds heal within one to three weeks, depending on the surface area of the tegument eaten by Nile Tilapia. Healed wounds appear darker in color.

Effect of three types of liquid compost combined with Avicennia marina leaves on growth and survival of tiger prawns (Penaeus monodon)

The sustainability of prawn farming in brackish water ponds is controversial because of low yields and a history of mangrove clearing. Low yields are due largely to insufficient preparation of pond bottoms. Mangrove trees are often planted on pond bunds as window dressing. This study examines the effect of three types of liquid compost from vegetable, fruit, and both vegetable and fruit in tanks to which whole or chopped Avicennia marina leaves have been added to mimic local pond conditions. In a split-plot design, 28 square tanks were each stocked with one hundred 15-day-old post-larvae tiger prawns (Penaeus monodon). Four tanks were used as controls and 24 were assigned to the treatments, 12 with whole and 12 with chopped leaves. Of the treatment tanks, 4 received liquid compost from vegetable, 4 received fruit, and 4 received mixed vegetable and fruit. Shrimp were weighed at the start, halfway point, and the end of the 50-day trial, and fed at 5% of the estimated total weight; survival was counted at the end. The survival rates of treatments and controls (65–76%) were not significantly different. Shrimp in water with vegetable compost grew significantly faster (2.7% day−1) than in both treatments with fruit (2.5% day−1), while all treatments were associated with significantly faster growth than were the controls (2.0% day−1). The lower growth rate of shrimp fed fruit compost may have been due to dinoflagellates, which are known to negatively affect shrimp. Shrimp in tanks with chopped mangrove leaves grew slightly better than shrimp in tanks with whole mangrove leaves.

The The effects of decomposing mangrove leaf litter and its tannins on water quality and the growth and survival of tiger prawn (Penaeus monodon) post-larvae

Abstract. Rejeki S, Middeljans M, Widowati LL, Ariyati RW, Elfitasari T, Bosma RH. 2019. The effects of decomposing mangrove leaf litter and its tannins on water quality and the growth and survival of tiger prawn (Penaeus monodon) post-larvae. Biodiversitas 20: 2750-2757. Shrimp farming in Demak, Indonesia is often practiced in silvo-aquaculture systems in which mangrove trees are planted on pond bunds. As such, mangrove leaves and its substrates may have impact on penaeid shrimp production. In this area, mangrove re-growth proceeded with Avicennia marina while planting is mostly done with Rhizophora apiculata. We compared the effects of decomposing fresh leaves of A. marina and R. apiculata on water quality and on the performance of Penaeus monodon postlarvae (PL). A hundred of PL21 (postlarvae aged 21 days with weight of 0.28 g) were stocked in each of 30 aerated tanks containing 800 liters of brackish water (salinity of 21 ppt) for 37 days. Five treatments with three replicates for each mangrove species were assigned by adding into the tanks of 0.125, 0.25, and 0.5 g L-1 of air-dried leave, 0.125 of g L-1 minced leave and 0.125 g L-1 of leachate of minced leaves. The PLs were fed 3 times daily with pellets at 10 % of initial total body weight. Water quality parameters were recorded daily. Tannin, H2S and NH3-N concentrations were measured every ten days. Prawn's body weight (BW) was measured and specific growth rate (SGR, % day-1) and survival rate (SR, %) were calculated after the end of experiment. Results were analyzed with ANOVA and Pearson's correlation. The results showed that tannin in decomposing mangrove leaf litter up to a concentration of 0.5 mg g-1 did not have a significant effect on water quality and on the growth and survival of P. monodon PL. However, increasing leaf litter concentrations showed an increase in NH3-N concentration due to organic matter degradation. The accumulation of NH3-N may have caused the slow growth of shrimp PL in A. marina treatment. Shrimp PL in leaf litter leachates treatment has a higher growth rate than those PL in regular leaf litter in relation to nutritional value. Survival and growth varied from 62 ±14 to 70 ± 8% and 3.1±2.1 to 5.5±1.2% day-1, respectively. Although decomposing mangrove leaves of A. marina and R. apiculata had no toxic effects on P. monodon PL up to a concentration of 1.25 g L-1, but causing severe mortality for shrimp in tanks without water exchange. As a conclusion, the present of mangrove leaves in brackish water ponds with insufficient water exchange can be harmful to shrimps. However, if the water exchange is good, decomposed mangrove leaves can become organic fertilizer that beneficial for the growth of natural food for the shrimps

The impact of shrimp pond effluent on water quality of Vasishta Godavari estuary with respect to brackishwater aquaculture, East Coast of India.

Estuary, where a river meets the Sea, provides high level nutrients both in water column and in sediment, making estuaries most productive natural habitat for brackish water aquaculture in the world. Estuary is subject both to marine influences and to river influences, causes variations in optimum hydro chemical parameters, which are suitable for brackish water aquaculture. Physicochemical studies were carried out to predict whether the variations are due to seasonal changes or due to aquaculture effluents in Vasishta Godavari Estuary (VGE).Towards this objective water samples were collected in VGE from five stations during Oct-2016; Monsoon with Farm Period (FP)-1 discharge, Jan-2017; Postmonsoon with FP-2 beginning ,June-17;Premonsoon with FP-3 discharge. Influence of seawater was felt in the estuary up to a distance of 40 km from the mouth towards the head.Though fluctuations in physicochemical parameters were noticed, these are in optimum range for brackish water aquaculture. Concentration of nitrate, silicate was rich, where as phosphate, nitrite was poor. Salinity stratification was more marked than that of dissolved oxygen. Salinity gradient (surface to bottom) increases towards seaward during the discharges of FP-1 & FP-3 and not follows any trend during the beginning of FP-2. The field and laboratory observations on the water quality during the discharge and beginning of farm periods revealed that the study area have high potential for brackish water pond shrimp culture development based on values obtained which were in conformity with recommended values for shrimp culture.

Nutrient and fatty acid composition of cultured and wild caught gold-spot mullet Liza parsia (Hamilton, 1822)

The gold-spot mullet, Liza parsia (Hamilton, 1822) is a common mullet species that constitutes year round thriving fishery in the shallow coastal waters, estuaries, mangrove swamps and brackishwater lakes along the coast of India. Nutrient and fatty acid composition were analysed in cultured and wild caught L. parsia of different size groups. Fish were cultured with formulated pelleted feed in brackishwater pond at Nagayalanka (15.9450 N; 80.9180E), Andhra Pradesh, India. Wild samples of L. parsia were caught from the same region near Krishna River. The fishes were categorised into four size groups (<50 g, 50-100 g, 101-150 g and >150 g) from both sources. The moisture and ash content were higher (p<0.05) in wild fishes (75.85 and 1.39%) compared to cultured ones (72.96 and 1.29%). Cultured L. parsia had higher (p<0.05) crude lipid (2.12-8.73%) across all size groups compared to wild group which recorded crude lipid in the range of 0.67-3.10%. However, no significant change was observed for crude protein between wild and cultured fish. The quantities (mg 100 g-1 of fish muscle) of 18:2n-6 fatty acids were significantly (p<0.05) higher by 12 fold in farmed fish, whereas 20:4n-6 was higher (p<0.05) by two times in captive L. parsia. Significant (p<0.05) difference was observed in docosahexaenoic acid (DHA) content between the cultured and wild fish (108.60 and 89.90 mg 100 g-1, respectively) but not in eicosapentaenoic acid (EPA) (110.59 and 115.03 mg 100 g-1 respectively). The consumption of 100 g L. parsia fish which was above 100 g size of both wild and farmed could meet per day (250 mg) dietary needs of EPA and DHA.

Antibacterial activity of Caulerpa racemosa against pathogenic bacteria promoting “ice-ice” disease in the red alga Gracilaria verrucosa

Increasing ocean temperatures associated with climate change have triggered the occurrence of diseases in marine resources such as macroalgae or seaweed. “Ice-ice” is one of the most devastating diseases affecting economically important seaweeds such as Gracilaria and Eucheuma. In this study, we investigate the bacterial composition of diseased and healthy Gracilaria verrucosa, a red seaweed cultured in brackish water ponds in Takalar, Indonesia. Morphologic and phenotypic characteristics showed that the isolates from diseased Gracilaria belong to various genera: Vibrio, Chromobacterium, Flavobacterium, Pseudomonas, and Achromobacter. Several bacteria were also isolated from healthy Gracilaria including Corynebacterium, Serratia, Shigella, Micrococcus, Proteus, and Flavobacterium. Using Koch’s postulates, bacterial pathogenicity was established by bath exposure of naive G. verrucosa to each of the bacteria isolated from diseased Gracilaria resulting in symptom characteristic of “ice-ice” disease. The antibacterial property of the green seaweed Caulerpa racemosa against the pathogenic bacteria was assessed using extracts that were prepared with solvents of various polarities such as hexane, chloroform, ethyl acetate, methanol, and methanol-water. The highest antibacterial activity was observed in methanol extracts Caulerpa while extracts using the other solvents showed moderate to low activities. These findings demonstrate the potential of Caulerpa to inactivate bacterial pathogens associated with “ice-ice” disease.

ESTIMASI HERITABILITAS DAN RESPONS SELEKSI IKAN NILA HITAM (Oreochromis niloticus) DI TAMBAK

Genetic improvement in the establishment of a rapid growth strain of Nile tilapia might be achieved through selective breeding program This research was aimed to estimate heritability and response selection of nile tilapia in brackishwater pond. Breeding activity was carried out in fresh water in hapa 2x1x1 m. Males and females were breeding in pairs with a ratio of 1: 1. The number of established families was 19 families of 50 broodstock pairs. Harvesting of larvae was done on day 14. Larvae were collected and then kept in net 2 x 2 x1 m with stocking density 125 fish/m2 for 60 days. The next stage was sexing by grouping the male and female populations in each family. Grow out was carried out in net cage (3 x 5 x1.5 m ) that were placed in brackiswater pond at salinity 25–30 g/L with density 10 fish/m2. Selection of broodstock in the male and female populations was done on weight of 250–300 g. Cut off selection was determined on weight from 316 to 382g (male) and 221–315 g (female). The results of this study showed that the estimation value for heritability of male and female were 0.42 ± 0.22 and 0.42 ± 0.23 and the estimation value for response selection were 10.66% (male) and 10.92% (female).

MULTI-AGE DUCK FARMING SYSTEM IN PONDS, COMPARING ITS PRODUCTION AND PROFIT: A CASE STUDY AT TAKALAR DISTRICT OF INDONESIA

The study was aimed to draw a comparison between the production and proft of duck eggs in the multi-age duck farming in brackishwater ponds. Multi-age is defined as layer ducks in two or three age group (level 2 or 3) that is farmed collectively in one cage. Evaluative method was applied to 110 ducks in each level. The ducks in level 2 consist of two age groups: 6-14 and 15-23/24 months, 36 ducks each. Level 3 has three age groups: 6-11, 12-17 and 18- 23/24 months containing 36, 38 and 36 ducks, respectively. Each level was contained in a 20m2 cage in the same pond with a 100m gap between cages. The ducks are allowed a natural environment to freely swim in the pond and rest in the cage. The ducks are kept for four months. The t test statistics was used to compare the production and profit of duck eggs in level 2 and 3. The result showed a non-signficant difference in egg production betweel level 2 and 3 (p 0.05) was identified where level 2 gave a higher profit by IDR 308,000 (USD 21,63) than level 3. Based on the comparison in egg production and profit, it is concluded that the multi-age duck farming level 2 and 3 deserves perpetuation or development

Optimisation of nursery rearing for megalopa of giant mud crab Scylla serrata (Forskal, 1775)

Three nursery rearing trials were conducted to overcome the inconsistent survival of megalopa of the giant mud crab Scylla serrata (Forskal, 1775) during metamorphosis to crab instar. In the first trial, 3-4 days old megalopa (4.73 mg mean body weight) were stocked in hapas erected in outdoor brackishwater ponds and indoor fiberglass (FRP) tanks at densities of 500 nos. m-2 and 1 no. l-1 respectively and reared for 15 days using minced clam meat (Meretrix casta) as feed. Outdoor hapas were provided with seaweed, Gracilaria tenuistipitata as shelter. Mean survival rate of crab instar following three consecutive runs were significantly higher (p<0.05) for megalopa reared in outdoor hapas (57.7±2.7%) over indoor FRP tanks (24.1±2.2%). To ascertain the life stage that yields optimal survival on weaning from indoor hatchery to ponds, zoea 5 (Z5) and megalopa 1-day old (M1), 2-day old (M2), 3-day old (M3) and 4-day old (M4) were reared in hapas for15 days and fed on minced clam meat. Three day and 4-day old megalopa demonstrated significantly higher survival rates (p<0.05) of 62.3±3.08% and 69.6±2.35% respectively to crab instar stage at conclusion of the trial. Megalopa (3-4 days old, 5.05 mg mean body weight) were stocked to 100 l tanks (stocking density - 1 no. 4 l-1) and reared for a period of 8 days using different feeds viz., artemia biomass (T1), minced clam meat (T2), crab larvae (T3) and artemia nauplii (T4) in the third trial to evaluate various production parameters. Crab instar conversion rate (number of crab instars/number of megalopa stocked × 100) was significantly higher (p<0.0001) for megalopa fed using artemia biomass (T1) and minced clam meat (T2) at 74.66±5.81% and 72.00±2.30% respectively. Results of the present study indicate that, high density rearing (500 no. m-2) of megalopa (3-4 days old) in outdoor hapas provided with seaweed refuge for short periods (15 days) would yield higher survival rate to crab stage. Nursery rearing of megalopa in ponds reduces the hatchery phase in mud crab larval rearing and maximise production of crab instars.

Economic valuation from direct use of mangrove forest restoration in Balikpapan Bay, East Kalimantan, Indonesia.

Background: The mangrove forests in Balikpapan Bay, Indonesia, have been used as a source of livelihood for local community more than 150 years. Since the natural products of the mangrove forest, such as wood and seafood, are not able to meet the economic needs of the local community, some areas have been converted into brackish water ponds with traditional aquaculture systems. The growth of brackish water ponds over the last five decades has been identified as the main cause of ecosystem destruction. However, the mangrove ecosystem has been restored naturally through tidal action and seeds falling from mangrove trees. Methods: This study focused on the mangrove tree species Rhizophora apiculata, with ages ranging from 3 to 40 years. Initially, the study site (area, 1 ha) was plotted. The study sample size included 30% of the local population, chosen by systematic random sampling. The data collection was undertaken as follows: 1) measurement of the diameter and height of mangrove trees; 2) observation of local fish auctions; and 3) interviewing of fishers and local communities regarding the direct use of the natural products of the mangrove ecosystem. Results: It is suggested that the total income from wood production is IDR 742,425,000 year -1 or US $0.933 person -1 day -1. Furthermore, the total income from fishing is IDR 1,080,353,280 year -1 or US $1.43 person -1 day -1. Pre-thinning income level for wood harvesting is still low. The income difference between wood production and fishing resulted in the rate of overfishing reaching 45.5%. The highest observed wood production was reached at the age of 25 years, and the highest value of mean annual increment (MAI) is 5.39 m 3 ha -1 at the age of 40 years. Conclusions: This study showed that tree thinning, ranging from 90 to 350 trees ha -1, can increase the value of MAI by around 24.5%.

Economic valuation from direct use of mangrove forest restoration in Balikpapan Bay, East Kalimantan, Indonesia

Background: The mangrove forests in Balikpapan Bay, Indonesia, have been used as a source of livelihood for local community more than 150 years. Since the natural products of the mangrove forest, such as wood and seafood, are not able to meet the economic needs of the local community, some areas have been converted into brackish water ponds with traditional aquaculture systems. The growth of brackish water ponds over the last five decades has been identified as the main cause of ecosystem destruction. However, the mangrove ecosystem has been restored naturally through tidal action and seeds falling from mangrove trees. Methods: This study focused on the mangrove tree species Rhizophora apiculata, with ages ranging from 3 to 40 years. Initially, the study site (area, 1 ha) was plotted. The study sample size included 30% of the local population, chosen by systematic random sampling. The data collection was undertaken as follows: 1) measurement of the diameter and height of mangrove trees; 2) observation of local fish auctions; and 3) interviewing of fishers and local communities regarding the direct use of the natural products of the mangrove ecosystem. Results: It is suggested that the total income from wood production is IDR 742,425,000 year -1 or US $0.933 person -1 day -1. Furthermore, the total income from fishing is IDR 1,080,353,280 year -1 or US $1.43 person -1 day -1. Pre-thinning income level for wood harvesting is still low. The income difference between wood production and fishing resulted in the rate of overfishing reaching 45.5%. The highest observed wood production was reached at the age of 25 years, and the highest value of mean annual increment (MAI) is 5.39 m 3 ha -1 at the age of 40 years. Conclusions: This study showed that tree thinning, ranging from 90 to 350 trees ha -1, can increase the value of MAI by around 24.5%.

Study of the Dynamic Density and Diversity of Plankton at Different Brackishwater Pond Managements in Gresik, East Java

The success of fish and shrimp farming is strongly influenced by the improvement of water quality, which is measurable from physical, chemical and biological parameters. Biological parameter refers to the presence or absence of plankton. Plankton is a microscopic- sized organism whose life drifts with the current. Plankton has a favorable type of group, and this type of adverse group is affected in pond production. A way to understand the group, the density and diversity of plankton in a pond one of them is to know the management of ponds, both traditional ponds and semi-intensive ponds. This research was conducted in traditional pond of Pandanan village and Tambak Semi Intensive Village of Ambeng-ambeng Gresik, East Java. It aimed to find out the dynamics of density and plankton diversity with different management. The method employed was survey method, which is is a research method aimed to describe the phenomena that exist regardless the time of occurrence. The results were presented in descriptive form. The result of total density of plankton of traditional pond was about 102-793 ind / l, while semi intensive density of total plankton density reached 59-980 ind / l. The results of traditional ponds diversity index ranged from 0.119 to 0.159 ind / l in semi intensive ponds 0.121-0.159 ind / l. Traditional fish dominance index values ranged from 0.1 to-0.338ind / l, and semi intensive ponds ranged from 0.172-0.558 ind / l. The nitrogen values of traditional and semi-intensive ponds were 0.042 - 0.314 mg / l and 0.048 - 0.224 mg / l respectively. The result of measurement of phosphorus value of traditional pond successively ranged from 0,02 to 0,042 mg / l and 0,007 - 0,031 mg / l for semi-intensive pond. The result of measurement of N / P ratio of traditional ponds consecutively ranged between 3,545 and 8 mg /, and semi intensive pond fpr 4,272 - 9.857 mg / l. The results of water quality assessment increased and decreased in the value of dissolved oxygen, ranging between 3.28 and 5.32 mg / l for traditional ponds and 5-8.25 mg /1 for semi-intensive ponds. The pH of traditional pond ranged from 6 to 7.89 and 7 to 9.2 for semi-intensive ponds. The temperature of traditional ponds ranged between 28 and 31°C and semi intensive pond at 29-31°C. Research has been done to conclude that.

Economic valuation from direct use of mangrove forest restoration in Balikpapan Bay, East Kalimantan, Indonesia

Background: The mangrove forests in Balikpapan Bay, Indonesia, have been used as a source of livelihood for local community more than 150 years. Since the natural products of the mangrove forest, such as wood and seafood, are not able to meet the economic needs of the local community, some areas have been converted into brackish water ponds with traditional aquaculture systems. The growth of brackish water ponds over the last five decades has been identified as the main cause of ecosystem destruction. However, the mangrove ecosystem has been restored naturally through tidal action and seeds falling from mangrove trees. Methods: This study focused on the mangrove tree species Rhizophora apiculata, with ages ranging from 3 to 40 years. Initially, the study site (area, 1 ha) was plotted. The study sample size included 30% of the local population, chosen by systematic random sampling. The data collection was undertaken as follows: 1) measurement of the diameter and height of mangrove trees; 2) observation of local fish auctions; and 3) interviewing of fishers and local communities regarding the direct use of the natural products of the mangrove ecosystem. Results: It is suggested that the total income from wood production is IDR 742,425,000 year-1 or US $0.933 person-1 day-1. Furthermore, the total income from fishing is IDR 1,019,056,640 year-1 or US $1.28 person-1 day-1. Pre-thinning income level for wood harvesting is still low. The income difference between wood production and fishing resulted in the rate of overfishing reaching 37.3%. The highest observed wood production was reached at the age of 25 years, and the highest value of mean annual increment (MAI) is 5.39 m3 ha-1 at the age of 40 years. Conclusions: This study showed that tree thinning, ranging from 90 to 350 trees ha-1, can increase the value of MAI by around 24.5%.

Correlation of Major Mineral Properties in Brackish Water Ponds Environment and Pacific White Shrimp Litopenaues vannamei Survival, Growth and Production

Correlation of Major Mineral Properties in Brackish Water Ponds Environment and Pacific White Shrimp Litopenaues vannamei Survival, Growth and Production

THE CHANGES OF ENVIRONMENT AND AQUATIC ORGANISM BIODIVERSITY IN EAST COAST OF SIDOARJO DUE TO LAPINDO HOT MUD

Lapindo hot mud to overflow and flood the east coast of Sidoarjo for 9 years has causedchanges in environmental factors, particularly aquatic ecosystems environment. This has an impact onbiodiversity of aquatic ecosystems in the eastern coastal Sidoarjo. This study aims to determine the quality ofaquatic ecosystems on the east coast of Sidoarjo contaminated by Lapindo hot mud and the impact onbiodiversity of aquatic organism. Data taken from 5 station consists of wetlands ecosystems, river, brackishwater ponds, estuaries, and coastal covering area districts of Porong, Jabon, Tanggulangin, and Sidoarjo, EastJava, Indonesia. Determination of stations and substations did purposively based on distribution mapsLapindo hot mud. Data obtained in the form of physical and chemical parameters of waters, biodiversity ofaquatic organism analyzed descriptively and quantitatively, and compared as well as the quality standard.The results showed contamination of aquatic ecosystems by Lapindo hot mud has led to changesenvironment factors and declining biodiversity of the aquatic organism in the eastern coastal of Sidoarjo.

ANALISIS FAKTOR-FAKTOR YANG MEMENGARUHI PRODUKSI IKAN BANDENG DI KECAMATAN MA’RANG KABUPATEN PANGKEP

Fishery development in Province of South Sulawesi can be devided into two categories, they are marine culture and fisheries, include wild fishery and aquaculture. One of aquaculture is brackish water pond. There are several kinds of fish that can grow in brackish water pond, such as milkfish. Milkfish is a potential commodity which is not only for consume but also for export to abroad. The aim of this research is to knowing the factors which affects the production of milkfish in fishpond. The basic research which used is Explanatory Research. This research takes place in Ma’rang subdistrict Pangkep District. The population is all fisherman which total there are 804 fishermen. Simple random sampling is used to get 80 fishermen as samples. They are consist 57 fishermen in Talaka Village and 23 fishermen in Pitue Village. Primary data is gathered by doing interview with the fishermen. This research is used Cobb-Douglas function for analysis. The results of this research show variable of area of fish raising place, young milkfish, fertilizer, burden and region dummy are have significant effect toward production of milkfish in brackish water pond, while labour, feed, age and experience have no effect toeard production pf milkfish in brackish water pond.

Effects of Dosage of Mix.Microorganisms in Feed Raw Materials Fermentation Containing Sargassum sp. on Growth Performance, Chemical Body Composition and Hepatosomatic Index of Milkfish, Chanos chanos Forsskal

Mixed microorganisms consist of bacteria, fungi, yeasts, and molds that produce important enzymes to ferment raw materials, thereby increasing the nutrient content of milkfish feed. This study aims to examine various doses of mix. microorganisms fermented raw materials on growth performance, chemical composition of the body, and hepatosomatic index of milkfish. Milkfish weighing 28.40 ± 0.11 g is kept in hapa of 1 m3 and placed on brackish water ponds. The test feed contains Sargassum sp. and formulated from raw materials fermented with mix. microorganism (control, 10, 15 and 20 mL / 100 g). The experimental results show the relative growth rate (%) and the growth of biomass (g) of milkfish fed with fermented feedstock with a dose of 10 mL / 100 g (122.77 ± 3.00%, and 522.05 ± 12.19 g ), the real feed is higher than the other dose. The fat content, crude fiber, and energy of test fish fed with fermented feedstock with 10, 15, and 20 mL / 100 g doses were significantly lower, while the hepatosomatic index was significantly higher than the control. (91.11-97,78%), protein content and NFE or Nitrogen Free Extracts (66.81 ± 0.41 72.33 ± 0.28% and 0.88 ± 0.38- 2.24 ± 0.92%), hepatic and muscle glycogen (7.16 ± 0.25-7.3 ± 0.31 mg / g and 6.16 ± 0.16, 6.51 ± 0.35 mg / g) were the same in all treatments. Thus, a dose of 10 mL / 100 g feed ingredients is the best dose in fermenting feed ingredients.Keywords: fermentation, milkfish, mix. microorganism, artificial feed, Sargassum sp.

PELAPISAN SOSIAL-BUDAYA PESISIR KELURAHAN MANGKANG KULON, SEMARANG

The purpose of this study is to identify economic conditions of the fishers and fish farmers and to understand the social stratification and work relation among the coastal society in Mangkang Kulon, a coastal area, with the main income almost entirely dependent on the sea and coast land. Social stratification is a society's categorization of people into socioeconomic strata, based upon their occupation and income, wealth and social status, or derived power (social and political). As such, social stratification is the relative position of person or group within a sociocultural system, category, geographic region, or social unit. Social stratification is the distinction of population or society into classes in multilevel classes (hierarchical); its manifestation is the presence of the upper class, middle class, and lower class.Primary data were collected from the local fishers. Four fishers and two brackish water pond cultivators were in-depth interviewed. Secondary data (village monograph) were collected from the village office. Data were analyzed descriptively. There were three social stratifications found out and formed in the area of Rukun Warga I Mangkang Kulon based on the income among coastal society. First the upper strata, which consists of gogol tambak, second the middle strata which consists of tambak pandega, third the lower strata of individual petty fishers and tambak manual workers.

Scaling up of tigershrimp (Penaeus monodon) production in brackishwater pond under diversified cropping regimes

To develop a scientific and affordable shrimp farming system for marginal to medium farmers with low inputs and higher returns by scaling up of production per unit area, shrimp culture was practiced with 3, 5 and 7/m2 stocking densities for the period of 60 days as short cycle and 120 days as long cycle. All the hydrographical parameters were found congenial in different treatments except dissolved oxygen (DO) in case of higher stocking density and long culture pattern. However, the specific growth rate (SGR) was optimal in both culture cycle but increased sharply in first 3-4 weeks of grow out period. Distinct survival rate were found in different treatment which was ranged from 86.39 to 90.96% but did not show significant difference (P>0.05%) among the treatments of short and long culture cycle. Total yield was ranged from 990 kg/ha to 1998 kg/ha for short cycled double and 1012 kg/ha to 2032 kg/ha for single cropping pattern. Highest production was obtained under the stocking densities of 7/m2although the average production showed significant difference (P<0.05%) among the treatments of both culture patterns. The food conversion ratio (FCR) value seems similar for all cropping patterns and ranged between 1.15 and 1.57. Except stocking density of 7/m2 at short cycle culture, net benefit were significantly (P>0.05%) higher in long cycle crop than that of aggregate of two short cycle crops. But benefit cost ratio (BCR) in short culture cycle is significantly (P>0.05%) higher than that of long culture (120 days) which indicates higher net benefit as well as positive feasibility of short culture system. Considering the infrastructural facilities in farm level and resource capability, this shrimp farming technology would be appropriate to boost up the production and income particularly for marginal to medium farmers.Asian J. Med. Biol. Res. March 2018, 4(1): 27-35

Dominant Water Quality Variables Affecting Plankton Abundance in Traditional Brackish Water Ponds of Tiger Shrimp (penaeus monodon fabr.) in Pasuruan Regency, East Java Province

ABSTRACTIn applying traditional brackish water pond aquaculture of tiger shrimp (Penaeus monodon), plankton is one of water micro organisms that plays an important role as natural food and stability indicator of water or aquatic environment in which life and growth of aquatic organisms depend on water quality variables, both physical and chemical properties. This research objective was to find out the effects of dominant water variables on plankton abundance in brackish-water pond. The research was conducted in traditional brackish water ponds of tiger shrimp in Pasuruan Regency, East Java Province. The research was conducted through direct measurements in the field and also collection of plankton and water samples. Those were then analyzed in the laboratory. Better change to analysis used in this study was regression model analysis was based on the smallest square method. Dependent variables was plankton abundance and independent variables were the water quality variables such as temperature, dissolved oxygen, salinity, pH, total suspended solid (TSS), nitrite, nitrate, ammonia, phosphate, iron (Fe), and total organic matter (TOM). The result showed that range of plankton abundance was 20.0-6,360 individuals/L with average 401.3 individuals/L. There was a significant relationship between plankton abundance and TSS which negatively affected plankton abundance as much as 0.52 or 52%. Based on index values of average dominance, variety, and uniformity, the brackish water pond water or aquatic area in this study was categorized as moderately stable, where plankton genera were well distributed and there was no genus dominating other genus.