Brackish Water Ponds Research Articles

Rhodobium pfennigii sp. nov., a phototrophic purple non-sulfur bacterium with unusual bacteriochlorophyll a antennae, isolated from a brackish microbial mat on Rangiroa atoll, French Polynesia

A novel budding purple non-sulfur bacterium (strain AR2102(T)) was isolated in pure culture from a microbial mat that had developed in brackish-water ponds on the coral rim of the atoll of Rangiroa (Tuamotu Islands, French Polynesia). Single cells of this strain were rod-shaped and motile by means of polar flagella and divided by budding. Their intracellular photosynthetic membranes were of the lamellar type. Bacteriochlorophyll a and carotenoids of the normal spirilloxanthin series, with spirilloxanthin as the main carotenoid, were present as photosynthetic pigments. Bacteriochlorophyll a absorption in the infrared portion of the light spectrum exhibited an unusual in vivo absorption peak at 909 nm. The strain grew optimally under photoheterotrophic conditions, but could grow photolithotrophically on thiosulfate or chemo-organotrophically under micro-oxic conditions. Optimal growth occurred in the presence of 1-2 % NaCl. Comparative sequence analysis of the 16S rRNA gene placed strain AR2102(T) within the class Alphaproteobacteria, in a cluster with Rhodobium species. Representatives of this cluster form a closely related group of slightly to moderately halotolerant to halophilic, rod-shaped, purple non-sulfur bacteria that divide by budding. The new isolate exhibited some differences in physiology (no utilization of alcohols or carbohydrates) and genetic characteristics (low relatedness in DNA-DNA hybridization) as well as in its relation to light (differences in absorption wavelengths) from previously described Rhodobium species. Consequently, we propose that strain AR2102(T) (=DSM 17143(T)=ATCC BAA-1145(T)) should be considered as the type strain of a novel species within the genus Rhodobium, Rhodobium pfennigii sp. nov.

AN EMPIRICAL TYPOLOGY OF BRACKISH-WATER POND AQUACULTURE SYSTEMS IN THE PHILIPPINES: A TOOL TO AID COMPARATIVE STUDY IN THE SECTOR

Aquaculture in the Philippines is long-established but has witnessed rapid technical change in the last 20 years with the introduction of hatchery technology and commercial feed mills changing the production possibilities for a fishpond operator. To understand the sector, a typology of brackish-water pond farming systems is constructed using multivariate methods (principal components analysis, cluster analysis). Eight input variables across all major factors of production are used in the analysis, gathered from a net sample of 136 farms in two regions in 2003. Three latent variables are described, accounting for 58% of variance in the original data: specialization; land vs. labor intensity; and feeding intensity. Five clusters (farm types) are subsequently described: extensive polyculture (40% of sample); semi-intensive prawn-oriented polyculture (11%); low-input labor-intensive farms (27%); very large, extensive milkfish-oriented farms (8%); and semi-intensive milkfish monoculture farms (14%). Implications for technical efficiency estimation and comparative study of economic indicators are discussed.

Potential for culture of grey mullets (Pisces:Mugilidae) in Ghana

The potential for culture of grey mullets in Ghana was investigated in fresh and brackish water ponds. Growth performance of fish that were given supplementary feed was better than those cultured without supplementary feeding. However, the difference in growth was not significant. The difference between the growth of fish raised in fresh water and that of those raised in brackish water ponds was also not significant. Feed conversion ratio of 6.0 was recorded in fresh and brackish water ponds while survival rates ranged from 43.4 to 68.8 per cent in the various ponds. Within a 270- day culture period, fish production of 336.5 and 287.0 kg ha-l were recorded in ponds with and without feed, respectively. The mean final weight of Mugil curema (Valenciennes) was the highest among the species cultured. The results for this study compared favourably with other published works and indicated a good potential for the culture of grey mullets in Ghana. Ghana Journal of Science Vol. 44, 2004: 19-27

TIGER SHRIMP (Penaeus monodon) GROWTH AT DIFFERENT STOCKING DENSITIES IN HIGH SALINITY POND USING MANGROVE RESERVOIR

High salinity pond water ranging from 33—45 ppt between July and October is one of the problems occurred in western part of South Sulawesi brackishwater ponds. It is necessary to know if tiger shrimps grow well in such salinity, since the optimum salinity range for the growth of tiger shrimp is 15—25 ppt. The objective of the research is to know the tiger shrimp production at different stocking densities cultured in high salinity pond in mangrove reservoir. Twelve pond compartments of 500 m2 each were arranged randomly for three treatments of shrimp stocking densities i.e. 4 , 6, and 8 pcs./m2 , where each treatment was in three replications. The result of study showed that shrimp production at 6 pieces/m2 was higher than that of 4 and 8 pieces/m2, with more efficient feed conversion was obtained in this stocking density (1.3) compared to treatment 4 pieces/m2 (1.5) and treatment 8 pieces/m2 (>3).

Experimental and numerical analysis of a tube-type networked solar still for desert technology

A tube-type solar still is proposed to integrate a conventional still and a water distribution network suitable to our concept of desert plantation. This still is directly set up on ground-like pipelines connecting brackish water or seawater ponds. The distilled water is immediately supplied to the plants under the ground by penetration without any extra water pipelines. The still is made of metal-free materials, e.g., plastic as vinyl chloride or PET resin which are inhibited from corrosion by seawater. Experimental data measured in our laboratory using infrared lamps showed the effectiveness of the method for productivity, the design of the basin tray and thermal efficiency up to 12.5%. Numerical simulations with experimental data as the temperature profiles at the tube walls estimated heat convection occurring within the still for modification of the Dunkle's model. Active convection over the basin was predicted in the half-cut tube type of the basin as compared with a conventional flat basin. The secondary convective circulations under the basin in case of the flat basin promote bulk flow from the upper part of the basin to the lower part, which suggests the necessity of insulating the lower part of the still. On the other hand, the tube basin enlarges the evaporative area over the basin and restricts the vapor circulation under the basin. Simulated results show that the performance of this type is not necessary for the insulation of a still and possible for setting up the lower part of the still under the ground. The tube-type solar still is very simple and has been researched, but further research is needed to make it a suitable technology for desert plantations.

Mangroves, Fishponds, and the Quest for Sustainability

Aquaculture, the farming of shrimp and other useful aquatic and marine plants and animals in artificially confined and tended ponds, pens, and cages, ranks as a phenomenal success story in global food production. In 1975, aquaculture contributed 8% to the overall yield of the world's fish harvest; now it provides more than one-third of the yield. Total aquaculture production in 2003 was 54.8 million metric tons valued at 67.3 billion in U.S. dollars. More than 90% of this output comes from Asia, where aquaculture has its origins and where this month's essay author has lived and worked all of her life. In her essay, Jurgenne H. Primavera, senior scientist of the Aquaculture Department of the Southeast Asian Fisheries Development Center based in Iloilo, Central Philippines, traces the recent history of aquaculture and the socioeconomic and environmental challenges that its rapid growth has wrought, especially for the mangrove ecosystems in which much of brackishwater pond aquaculture occurs. With an eye on all stakeholders, Primavera lays out how aquaculture is now falling short of the goal of sustainability and what steps might be taken to move the industry in that direction.

Comparative study of body composition of different fish species from brackish water pond

Seven species of fish (Catla catla, Cirrhinus mrigala, Cyprinus carpio, Hypophthalmicthys molitrix, Labeo rohita, Mori-Rahu Hybrid and Thalla-Rahu Hybrid) were collected from a brackish water pond near Muzaffargarh, Pakistan for the comparison of body composition. All the seven species were found relatively well adapted to the saline environment though some of them showed significant differences in body composition. Results obtained did not show any adverse effect of salinity on these fish species. The mean values of body constituents, except for protein content (dry and wet body weight) differed significantly (P<0.05) among various fish species. Minimum amount of water content and maximum amount of lipids, organic content and condition factor were observed in Cyprinus carpio indicating that Cyprinus carpio show overall better growth in brackish water as compared to other species. Cyprinus carpio may be recommended for culturing in such water bodies and farmers may be encouraged to farm this species on mass scale.

Y-Nauplii (Crustacea, Thecostraca, Facetotecta) from coastal waters of the Salento Peninsula (south eastern Italy, Mediterranean Sea) with descriptions of four new species

A collection (102 specimens of four different types) of Facetotecta nauplii (“Y-nauplii”) is described. It derives from different zooplankton samples collected between 1996 and 2004 at seven sites around the Salento Peninsula, south eastern Italy, the Mediterranean Sea. The collection sites (rocky coasts, submerged grottoes, one brackish water basin) are characterized by different salinity and bottom conditions. This is the first report of F. nauplii from a coastal brackish water pond. The nauplii belonged to types I, IV, VII, and IX of the current informal classification. This is the first report of types I, VII, and IX from the Mediterranean Sea. Types VII and IX are new also for Europe. Given the lack of the cypris-larva stage in this collection, the nauplius morphology is here proposed as valid to identify species. Some morphological features of the specimens presented here are not shared with any nauplius described from other parts of the world. On the basis of these differences four new species have been described (in alphabetic order: Hansenocaris corvinae, H. leucadea, H. mediterranea, H. salentina).

Effects of Salinity and Mangrove Detritus on Desorption of Metals from Brackish Water Desorption of Metals from Brackish Water and Shrimp

AbstractDesorption and bioaccumulation of Cd, Zn, and Pb were studied using naturally contaminated sediment from a brackish water pond in the Sunderban Biosphere Reserve in India. Pattern of desorption of the metals from the sediment and bioaccumulation in fingerlings of the teleost Oreochromis mossambicusand postlarvae of the shrimp Penaeus monodon were studied as a function of salinity and loading of detritus of a mangrove plant. Effects of both salinity and loading of detritus on bioaccumulation of the metals were studied under two conditions: either the animals were allowed free access to the sediment or access was denied. Ninety‐six hour experiments showed that desorption of Cd and Pb from sediment into water increased with salinity of the medium while desorption of Zn decreased. Salinity of the medium also had a significant effect on the bioaccumulation of metals by fish; Cd and Pb accumulation decreased in saline medium while the accumulation of Zn increased. Conditions of access to sediment had no effect on the bioaccumulation of metals by fish; effect of interaction between salinity and access condition was also insignificant. The access conditions, however, significantly influenced accumulation of metal by the shrimp postlarvae. The effect of interaction between salinity and access condition was insignificant in influencing the bioaccumulation of all metals except Zn. The accumulation of Zn increased as a function of the salinity of the medium when shrimp postlarvae were allowed access to the sediment. Desorption of metals from sediment to water were below detection limits when detritus of a mangrove plant was added to the medium. Both the level of detritus and the conditions of access influenced accumulation of metals by fish, but the effect of interaction between the two factors were found to be insignificant. Shrimp postlarvae showed net accumulation only of Pb in the presence of detritus and the accumulation of Pb increased when the larvae were separated from the sediment. The results are important in understanding the mobility of metals between solid and aqueous phases in brackish water environments that experience periodic fluctuations in salinity and fluxes of organic load in the form of mangrove detritus.

QUALITY OF SHRIMP SOLD IN THE MARKETS OF HYDERABAD, INDIA

ABSTRACTThe quality of brackish water pond cultured shrimp purchased from wholesale markets and retail sale points at the time of sale in Hyderabad city was studied. The various hygienic practices followed during the chain of commercial operations were also studied. All the samples collected from either markets had heavy filth. Out of 35 samples collected from the wholesale markets, light filth ranged from 2% to 28%, and it ranged from 8 to 22% in retail market samples. All the shrimp samples purchased from either source contained Staphylococcus spp, and 51% of the shrimp from wholesale markets were found to be contaminated with coliforms, 11% with Salmonella spp and 5% with Vibrio spp whereas 48% of the retail market samples contained coliforms, 11%Salmonella spp and 25% had Proteus spp. None of the samples collected from either source were contaminated with Listeria spp. The extent of bacterial contamination (cfu/g) was more for the samples purchased from the retail sale points than that of the wholesale markets.

Polyculture of milkfish Chanos chanos (Forsskal) and the red seaweed Gracilariopsis bailinae (Zhang et Xia) in brackish water earthen ponds

Growth, net production, and survival rates of milkfish cultured with Gracilariopsis bailinae at two stocking density combinations (T1– 30 fingerlings 100-m−2 pond+1-kg G. bailinae 4-m−2 net cage, T2– 30 fingerlings 100-m−2 pond+2-kg G. bailinae 4-m−2 net cage) in brackish water earthen ponds over four culture periods were determined. The control (T3) was stocked at 30 fingerlings 100-m−2 pond. Specific growth and production rates of G. bailinae were also calculated. There were no significant differences in mean growth, survival, and net production rates of milkfish between the three treatments. Irrespective of stocking singly or in combination with G. bailinae, significantly higher mean growth and mean production rates for milkfish were obtained during the third culture period of year 1 than those obtained from the other culture periods. Survival rates were not significantly different among the four culture periods. There were no significant differences in mean specific growth and mean net production rates between the two stocking densities of G. bailinae. Significantly higher mean specific growth and mean net production rates of red seaweed were also obtained during the third culture period of year 1 than those obtained from other culture periods. The production of milkfish and red seaweed was higher during the dry season. Growth rates of milkfish was positively correlated with temperature and salinity, while net production rates were positively correlated with temperature and total rainfall, but was inversely correlated with dissolved oxygen. G. bailinae growth and net production rates were positively correlated with water temperature and salinity. Results show that milkfish can be polycultured with G. bailinae grown in net cages in brackish water ponds at stocking density combination of 30 fingerlings 100-m−2 pond+1-kg G. bailinae 4-m−2 net cage.

Management of fish ponds built on acid sulfate soils in Buguma creek, Niger Delta, Nigeria

An experiment on the use of tidal flushing as a management technique for fishponds constructed in mangrove swamp of the Niger delta was carried out at the NIOMR/ARAC brackish water fish farm, Buguma, rivers state, Nigeria. The soils are highly acidic. pH in the wet state ranged between 6.75 and 7.70 but on air-drying, values went down to as low as 3.1. The soil acidifies the overlying pond water rapidly to ph less than 4.0 but upon tidal flushing the acidity was reduced remarkably with ph increasing to 7.1. The experiment revealed the effectiveness of tidal flushing in improving pond water quality and fish yield in brackish water ponds to about 1.25mt/ha/yr. Journal of Applied Sciences and Environmental Management Vol. 7(2) 2003: 39-43

Heavy Metal Deposition in Some Brackishwater Ponds of Sunderban (India) During Off-season of Shrimp Culture

Heavy Metal Deposition in Some Brackishwater Ponds of Sunderban (India) During Off-season of Shrimp Culture

Growth, Survival and Feed Conversion Rates of Sea Bream (Sparus aurata) Cultured in Earthen Brackish Water Ponds Fed Different Feed Types

Sparus aurata were cultured during an 8-month period in brackish water (salinity about 25 ppt) in an extensive culture system comprising eight earthen ponds, each with a water surface of 2.1 ha. Initial mean wet weight of fish in all ponds varied from 13.6 ± 1.9 to 19.2 ± 2.6 g/fish. The eight ponds were randomly allocated one of four experimental treatments (two ponds/treatment). In the first treatment, ponds were fertilized monthly with 100 kg urea and 50 kg triple super phosphate. The other treatments (2–4) were fed a locally produced tilapia pellet feed containing 25% crude protein made using different processes. Fish in the second treatment were fed tilapia feed pelleted by compressing machine, whereas in treatments 3 and 4 the pellets were produced by extruder machine (Wenger). Pellets in treatment 3 were floating and in the fourth were semi-sinking. Fish were fed pellets twice daily at 6% of their biomass. The mean final body weight for each treatment respectively was 104.6, 118.9, 156.8 and 158 g. Specific growth rate (SGR) of 0.8, 0.79, 0.99 and 0.95%/day, were obtained in ponds using only inorganic fertilizer, compressed sinking pellets, extruded floating pellets and extruded semi-sinking pellets, respectively. Feed conversion ratios (FCR) for treatments with the extruded tilapia pellets were 2.2 and 2.6 g feed/g gain, which were significantly (P < 0.05) better than treatments with compressed pellets (3.2 g feed/g gain). Production/ha/year were 1389, 1358, 945 and 682 kg fish for the groups fed with extruded floating, extruded semi-sinking, compressed and natural food, respectively. Under the present experimental circumstances, Sparus aurata fed extruded floating tilapia pellets (25% crude protein and 2,600 kcal/g), showed the best productive performance.

Preliminary Study on Genetic Distance of Vibrio parahaemolyticus Isolates from Diseased Fish and Shrimp Brackishwater Ponds by Random Amplified Polymorphic DNA (RAPD) in Malaysia

This study was conducted to determine the genetic distance of V. parahaemolyticus isolates from diseased fish (clinical) and shrimp brackishwater ponds (environmental) in Malaysia;four clinical isolates (numbered F1 to F4) and six environmental isolates (W1 to W6) from shrimp brackishwater ponds. The isolates were identified using conventional biochemical tests in combination with BBL Crystal Kit TM. Two published 10-mer arbitrary primers (Gen1-50-01 and Gen1-50-02) were used for detecting DNA polymorphisms. RAPDistance program (version 1.04) was used to analyze the RAPD patterns. Dendrogram was then constructed from the combined results of two primers using Neighbour-Joining Tree (NJTREE) algorithm. The primers detected DNA polymorphisms in all isolates except W1 and W2, which were DNA monomorphic. Each primer generated fingerprints of up to 20 bands, ranging from 100 to 6000 bp. Dendrogram elucidated a tree of two main clusters (A and B) where a close genetic distance between the clinical isolates (F2, F3 and F4) except isolate F1 was observed to be closer to environmental isolates W3 and W5. Isolates W1, W2 and W4 were found to be genetically far from any clinical isolates.

Small-scale morphological and genetic differentiation in the Mediterranean killifish Aphanius fasciatus (Cyprinodontidae) from a coastal brackish-water pond and an adjacent pool in northern Sardinia

Two samples of Aphanius fasciatus collected in the Pilo pond (northern Sardinia, Italy) and in an adjacent pool of small surface area were analysed morphologically (235 individuals) and genetically (a subsample of 58 individuals). The aims of the present study were (i) to test the hypothesis that different predation pressures may be associated with morphological and/or genetic differences between samples from each habitat and (ii) to assess the level of divergence between the two populations. Morphological analysis was based on the relative size of fins because it has been shown to be associated with predation pressure. The relative caudal fin area (caudal fin area/total body surface) was smaller in specimens from the pool, in both males and females, whereas no differences were found for the dorsal and anal fin areas. Caudal fins with higher aspect ratio (fin depth/fin length) were found in fish from the pool but not in the pond, due to a higher fin depth. We hypothesised that specimens from the pool would show smaller caudal fin area, since they are subject to lower predation pressure. Random amplification of polymorphic DNA (RAPD) analysis revealed a relatively high degree of both within- and between-sample genetic heterogeneity. The pond and pool samples exhibited heterozygosities, which did not differ significantly by t-test. Between-sample genetic divergence was highlighted by the coancestry coefficient (θ = 0.301 ± 0.059, P < 0.001) and analysis of molecular variance (AMOVA) (variance between sites = 41%, P < 0.001). Genetic divergence between sites with a relatively high genetic diversity within both samples suggested that the population in the pool did not originate from a single colonisation event with a small number of founders. The genetic divergence between the two populations is consistent with their differences in fin size.

Diet and harvesting regimen for the production of mud crab Scylla olivacea in brackish water ponds

: The effects of diet (fish bycatch or a mixed diet of 75% brown mussel flesh and 25% cooked cracked corn) and harvesting regimen (bimonthly selective harvesting, or single terminal harvesting) on growth, survival and production of mud crab Scylla olivacea (Herbst) in brackish water ponds were determined in a replicated factorial experiment. The crabs were stocked at 0.6 individuals per m2 for 118 days. There was no significant interaction (P > 0.05) between the diet and harvesting regimen treatments. Regardless of diet, the survival rate and net production of mud crabs were significantly higher (P < 0.05) when crabs were subjected to bimonthly selective harvesting than at single terminal harvest. Comparative cost–return analysis showed that bimonthly selective harvesting and mixed diet treatments attained higher net return and return on investment, and lower cost of production than the other treatments. Partial budgeting analysis showed that bigger profits can be earned by using a bimonthly selective harvesting and a mixed diet of 75% fresh or fresh-frozen brown mussel flesh and 25% cooked cracked corn.

Biological warfare in the garden pond: tadpoles suppress the growth of mosquito larvae

Abstract. 1. Although tadpoles and mosquito larvae may compete for scarce resources in natural freshwater systems, the mechanisms involved in such competition remain largely unstudied.2. Replicated artificial ponds were set up to examine the role of pathogenic interference (water‐borne growth inhibitors) in two tadpole–mosquito systems from south‐eastern Australia. One system comprised taxa that are commonly sympatric in freshwater ponds (tadpoles of Limnodynastes peronii and larvae of Culex quinquefasciatus) while the other comprised species that co‐occur in brackish water ponds (tadpoles of Crinia signifera and larvae of Ochlerotatus australis).3. Water that had previously contained tadpoles suppressed the rates of survival and pupation of mosquito larvae in both systems. Fungicide reduced or eliminated this effect, suggesting that the growth inhibitors may be fungal organisms (possibly the yeast Rhodotorula glutinis) from tadpole faeces. Fungicide also enhanced growth rates of tadpoles.4. These results suggest that interference competition between tadpoles and mosquito larvae is mediated by other organisms in some ecological systems.

Profitability and technical efficiency of aquaculture systems in pampaanga, philippines

We evaluate the profitability and technical efficiency of aquaculture in the Philippines. Farm‐level data are used to compare two production systems corresponding to the intensive monoculture of tilapia in freshwater ponds and the extensive polyculture of shrimps and fish in brackish water ponds. Both activities are very lucrative, with brackish water aquaculture achieving the higher level of profit per farm. Stochastic frontier production functions reveal that technical efficiency is low in brackish water aquaculture, with a mean of 53%, explained primarily by the operator's experience and by the frequency of his visits to the farm. In freshwater aquaculture, the farms achieve a mean efficiency level of 83%. The results suggest that the provision of extension services to brackish water fish farms might be a cost‐effective way of increasing production and productivity in that sector. By contrast, technological change will have to be the driving force of future productivity growth in freshwater aquaculture.

LOCAL ADAPTATION OF AN ANURAN AMPHIBIAN TO OSMOTICALLY STRESSFUL ENVIRONMENTS

Water salinity is an intense physiological stress for amphibians. However, some species, such as Bufo calamita, breed in both brackish and freshwater environments. Because selection under environmentally stressful conditions can promote local adaptation of populations, we examined the existence of geographic variation in water salinity tolerance among B. calamita populations from either fresh or brackish water ponds in Southern Spain. Comparisons were made throughout various ontogenetic stages. A combination of field transplant and common garden experiments showed that water salinity decreased survival probability of individuals in all populations, prolonged their larval period, and reduced their mass at metamorphosis. However, significant population × salinity interactions indicated that the population native to brackish water (Saline) had a higher salinity tolerance than the freshwater populations, suggesting local adaptation. Saline individuals transplanted to freshwater environments showed similar survival probabilities, length of larval period, and mass at metamorphosis than those native to freshwater. This indicates that increased tolerance to osmotic stress does not imply a loss of performance in freshwater, at least during the larval and juvenile phases. Despite the adaptive process apparently undergone by Saline, all populations still shared the same upper limit of embryonic stress tolerance (around 10 g/l), defining a window of salinity range within which selection can act. Significant differences in embryonic and larval survival in brackish water among sibships for all populations suggest the existence of a genetic basis for the osmotic tolerance.