Grow-out Ponds Research Articles

Bioenergetic modelling of effects of fertilization, stocking density, and spawning on growth of the Nile tilapia, Oreochromis niloticus (L.)

Abstract. A bioenergetic growth model was developed to examine the integrated effects of fertilization, stocking density, and spawning on the growth of tilapia, Oreochromis niloticus (L.), in pond aquaculture. The analyses showed that growth rates increase with higher levels of organic fertilization up to 500kg/ha/week. Growth rates increased with added food rations in ponds, reaching a maximum growth of 2-07g/day at about 44–48 days after stocking. Fish growth rates decreased with increased levels of stocking density. The stocking density for optimal growth is 1fish/m2; the optimal density for total harvesting weight and fish size is 2 fish/m2. Model sensitivity analysis indicated that tilapia growth is most sensitive to catabolism (metabolism) and anabolism (synthesis) coefficients, both of which are geometrically related to the fish body weight. Food assimilation efficiency (b) and the food consumption coefficient (h) have a modest effect on fish growth. Spawning in grow-out ponds can have a major effect on fish growth.

Use of Bagasse as a Feed Input to Semi‐Intensive Shrimp Growout Ponds

AbstractEfforts to reduce the cost of growout feeds for aquaculture have traditionally focused on the use of agricultural wastes as direct or indirect nutritional supplements to support semi‐intensive production levels. The merits of a low cost, sugar cane bagasse‐based feed for semi‐intensive production of Penaeus vannarnei were evaluated. Shrimp averaging 0.24 g each were stocked into 200 m2 earthen ponds at 20/m2 and cultured for a 12 week period. Two bagasse‐based feed treatments, a manure‐based treatment and a no‐feed input control, were compared in replicate ponds. One bagasse treatment (artificial manure) was designed to mimic manure and stimulate autotrophic and heterotrophic growth. The other bagasse treatment (bagasse alone plus inorganics) was designed to stimulate primarily autotrophic growth. Both bagasse treatments produced average growth rates of 0.78 g/wk, which were significantly greater than that of the manure treatment (0.57 g/wk). Lack of difference between the two bagasse treatments suggests that additional supplements used in making artificial manure probably were unnecessary to the nutrition of the shrimp. At harvest, bottom organics in the bagasse‐fed ponds were at least twice as great as manure‐fed ponds, and may have contributed to the lower survival associated with these treatments.

The occurrence, development and histopathology of monodon baculovirus in Penaeus monodon in southern Thailand

The occurrence, development and histopathology of monodon baculovirus (MBV) in larvae, postlarvae (PL) and broodstock of Penaeus monodon was studied over a period of 1 year in southern Thailand. In histological samples of captured male and female broodstock obtained from the Andaman Sea, the incidence of individuals with MBV occlusion bodies (OB's) was approximately 5.7% during the period. Absence of MBV virions in electron micrographs of oocytes of MBV-infected females, mature eggs and nauplii indicated that the virus may not be transmitted transovarially. Together, these facts suggest that elimination of MBV from hatcheries by screening of quarantined wild broodstock would be feasible. In the hatchery, baculovirus OB's began to be clearly identifiable in the hepatopancreas of larvae at the third zoeal stage. During all subsequent larval and PL developmental stages, there was a high incidence of infected individuals, some with extremely large numbers of OB's. The average incidence of PL positive for OB's in histological specimens approached 100% during the period of the study in a survey that included eight commercial PL producers on both the Gulf of Thailand and the Andaman Sea. However, the incidence of OB-positive animals gradually fell as the shrimp grew older and OB's were often undetectable in healthy juveniles derived from infected PL within approximately 2 weeks of stocking in grow-out ponds. In some instances, it was possible to follow groups of PL from the nursery stage through to harvest of market-size shrimp. Average survival data for such shrimp followed in a large number of ponds over a period of 1 year indicated that MBV was well tolerated by Penaeus monodon if other rearing conditions were optimal. However, in the event of environmental or other stress, the incidence of animals showing large numbers of MBV particles increased dramatically.

Acute toxicity of ammonia to juvenile gilthead seabream Sparus aurata under reduced oxygen levels

The effect of dissolved oxygen concentration on the toxicity of ammonia to juvenile (0.4–3.2 g) gilthead seabream ( Sparus aurata) was studied. The mean 96-h LC50 value of ammonia was 23.7 mg/l total ammonia-N (19.3–28.7, 95% C.L.; equivalent to 1.27 mg/l NH 3-N). By comparison, S. aurata is somewhat less sensitive to ammonia than salmonids and similar in sensitivity to nonsalmonids. Increased toxicity of ammonia was observed with decreasing oxygen level. Our data suggest that below a threshold of approximately 40% D.O. saturation, the response of S. aurata to ammonia is no longer linear. Under reduced oxygen level most of the mortality occurs within a few hours, apparently as a consequence of an additive toxic effect. No evidence of pathological changes was found in the gills, liver and kidneys of fish with lost equilibrium in the presence of added ammonia. Acutely toxic conditions for S. aurata may prevail in medium-flow systems (2–6 kg fish/m 2 and 50% total daily water exchange) where oxygen and ammonia levels are influenced by microbial and algal activities. In such systems, ammonia toxicity may increase as a result of increasing ammonia levels and decreasing oxygen concentration following crashes of phytoplankton populations. In high-flow systems typical of most hatchery and nursery tanks as well as some grow-out ponds, it is likely that the chronic effects of ammonia toxicity will be more important than the acute ones. The data suggest that increasing oxygen level by aeration is sufficient to reduce acute ammonia toxicity under certain situations.

Ulva lactuca Biofilters for Marine Fishpond Effluents. I. Ammonia Uptake Kinetics and Nitrogen Content

The potential of the seaweed Ulva lactuca as a biofilter for effluents of intensive marine fishponds in arid regions has been studied in Eilat, Israel. One kg (wet wt) nor2 of Ulva in 1 m2 tanks 60 cm deep, removed, during the day, over 90 percent of the ammonia from the fishpond effluents, at inflow fluxes up to 10 μιηο1β5 L1 h1 (0.14 mole m^d1)· At fluxes of 40μπιοΐ68 L1 h~3 (0.58 mole m2d1)9 nearly 40 percent were removed. Night time ammonia removal remained efficient at low ammonia fluxes. Ammonia uptake rate and percent nitrogen (N) in dry weight (DW) of the seaweed showed hyperbolic correlations with ammonia flux through the tanks. The data fitted the Michaelis-Menten kinetics, with a maximal uptake rate of 28 μηιοΐβδ L1 h1 (0.4 mole m~2d1). Pulse ammonia uptake rate was approximately four times that of continuous uptake. Maximal percent N in DW of U. lactuca, when stocked at 1 kg m 2, was 4.07. Increased stocking density (2, 4 and 6 kg m2) did not significantly affect ammonia uptake rate per tank. However, N-content was significantly higher, averaging 5.5 percent of DW. The data indicate that at low ammonia fluxes (below 10 μιηο1β8 L1 h1) U. lactuca was N-limited and that at higher fluxes the algae became gradually light limited. Our results indicate that 10m2 of Ulva biofilter can remove from the effluents of our intensive grow-out ponds over 90 percent of the ammonia produced by 1 kg of daily feed ration or by approximately 75 kg of fish.

Using Experimental Microcosms in Shrimp Research: The Growth‐Enhancing Effect of Shrimp Pond Water

AbstractAfter preliminary six week experiments showed that shrimp pond effluent from an intensive culture growout pond had the capacity to nearly double shrimp growth in laboratory tanks, an 18 day experiment was designed to determine if similar results occurred in the presence of high quality feeds. The results presented here corroborate the hypothesis that autochthonous factors in shrimp pond water stimulate shrimp growth. These results revealed that performance of currently available shrimp feeds is greatly improved in the presence of pond effluent, regardless of feed quality. Increased feed performance did not appear to be an artifact of supplemental feed availability in pond effluent. The implications from these experiments are that, even in intensive culture systems (above 40 shrimp per m2), in‐situ sources of nutrition play an important role in shrimp growth.

Production Costs of Juvenile Penaeid Shrimp in an Intensive Greenhouse Raceway Nursery System

AbstractThis analysis compared the use of an intensive nursery raceway system with direct stocking of post‐larval shrimp into growout ponds. The intensive raceway system allows two crops to be produced in Texas where only one crop is feasible with direct stocking. Both investment and operational costs are analyzed for three types of greenhouses and three types of raceways where the types vary in cost and lengths of life. Three growout pond stocking densities and two farm sizes were evaluated for each combination of greenhouse and raceway type. Investment costs ranged from $142,000 for the small farm using the least expensive greenhouse and raceway and utilizing the lowest stocking density, to about $2.3 million for the large farm using the most expensive greenhouse and raceway and the highest stocking density in the growout ponds. The operational cost was $7.60 and $9.71 respectively per 1,000 one gram juveniles produced. Under technology available at the time of this analysis, direct stocking growout ponds with PIS and producing one crop per year is more profitable than stocking one gram juveniles and producing two crops per year on the Texas coast.

The Sheepshead Minnow Cyprinodon variegatus—A Major Pest in Experimental Mariculture of the Gulf Killifish Fundulus grandis

AbstractIn an experimental Fundulus grundis hatch and growout system at the Cedar Bayou Mariculture Laboratory, egg‐to‐harvested‐fry survival rate of F. grundis was inversely related to percentage of Cyprinodon variegatus fry present (P < 0.05). Competition for food and space was noted in growout ponds, and high mortalities of F. grundis fry and adults occurred in mixed holding containers as a result of the agonistic behavior of C. variegutus. The hardiness and aggressiveness of the sheepshead minnow, its ability to enter water supplies as small prolarvae, its early sexual maturity, and rapid increase in ponds make it a significant pest in mariculture.Control measures for C. variegutus include screening incoming water; hand‐sorting contaminated broodstock and fry; and draining, drying, and refilling infested ponds to allow drought‐resistant eggs to hatch, then draining and drying again.

Off-Flavor in the Channel Catfish (Ictalurus Punctatus) Due to 2-Methylisoborneol and its Dehydration Products

Off-flavor in channel catfish is a serious problem in the commercial culture industry affecting 50-80% of growout ponds during the warmer months of the year. A microwave distillation technique has been developed to isolate volatile compounds from affected material. 2-Methylisoborneol (MIB) is the predominant compound isolated from off-flavored catfish during the growing season (April-October) in west Mississippi and is responsible for a musty type of flavor. Geosmin and other as yet unidentified compounds are also important causes of an earthy type off-flavor. 2-Methylenebornane and 2-methyl-2-bornene, dehydration products of MIB, were shown to contribute to the off-flavor problem. The absorption (2 hours) and depuration (48 hours) of MIB in catfish fingerlings were determined. MIB and its dehydration products are concentrated primarily in subepidermal and abdominal fat. Lesser concentration occurs in the liver and muscle tissue of off-flavored fish. Removing fish to clean, flowing water to purge MIB and geosmin could provide a partial means for off-flavor abatement.

Pathological changes in the tiger prawn, Penaeus monodon Fabricius, associated with culture in brackishwater ponds developed from potentially acid sulphate soils

Abstract. Abnormal brown discoloration of the gills, soft shells and decreased survival were identified among problems affecting Penaeus monodon Fabricius adults cultured in growout ponds developed from potentially acid sulphate mangrove soils in Johor, Malaysia. A histological and ultrastructural study showed that lamellar ferric hydroxide accumulation and associated gill changes, which led to hypoxic damage in other tissues, were probably responsible for many of the clinical abnormalities observed in the prawns.

Observations on the Ultrastracture of Baculovirus in Australian Penaeus monodon and Penaeus merguiensis

Baculovirus particles were found in the digestive gland of Penaeus monodon from hatcheries and grow-out ponds in northern New South Wales, northern Queensland and the Northern Territory. Similar particles were seen in a Penaeus merguiensis specimen caught off Townsville, Queensland. The particles were found in the hypertrophied nuclei of hepatopancreatic epithelial cells, both free in the nucleoplasm and occluded in large eosinophilic intranuclear inclusion bodies. The nucleocapsids of the particles measured 45-52 nm × 260-300 nm and resembled the baculovirus reported from Penaeus plebejus.

Energy structure and efficiency of a typical Chinese integrated fish farm

Integrated fish culture is an ancient practice in China and South East Asia but the structure, function and management of such systems have been little understood scientifically. This paper describes the energy input-output structure and its efficiency in marketable fish ponds at Nanhui Fish Farm in the Changjiang Delta of the People's Republic of China. In 1983–1984, the photosynthetic solar energy of the grow-out ponds was 1.15% of the total solar radiation. The net conversion efficiencies of biological energy, biological-industrial energy and total energy were 8.74, 8.43 and 3.40% respectively. The energy consumptions per tonne of fish were 46.68, 48.35 and 119.87 GJ for biological, biological-industrial and total energy respectively. About 60, 39 and 1% of the energy consumed came from solar radiation, biological energy and industrial energy respectively. Compared with 1982, the conversion efficiency in 1984 increased by 23.3%, which resulted from the modification to an aquaculture, animal husbandry and agriculture complex ecosystem, and from the improvement of the aquaculture system by increasing the proportion of grazing fish and decreasing the proportion of filtering fish as well as by increasing the input of compounded feeds. One of the remaining problems is the ecological energy trap of the soil at the bottom of the ponds.

A 13C/12C Tracer Study of the Utilization of Presented Feed by a Commercially Important Shrimp Penaeus vannamei in a Pond Growout System1

AbstractA study of added feed utilization by pond grown shrimp was done using seven feeds with different 13C/12C ratios, as expressed by δ13C. The pond shrimp did not track the δ13C value of the feed to the extent that tank grown shrimp did. For the seven pond experiments the δ13C data indicate that the added feed supplied between 23 and 47% of the growth carbon. This implies that between 53 and 77% of the growth is due to the grazing on pond biota. It is suggested that this experimental approach can be used to evaluate the relative contribution of presented dried feeds versus natural productivity in ponds as an aid to developing pond management strategies and optimum feeds.

Preliminary dataon larval survival of South American catfish, Rhamdia sapo

Larvae of Rhamdia sapo were fed four test diets of Artemia nauplii; a balanced diet formula; boiled egg yolk, coagulated blood and liver homogenate; and live zooplankton. The homogenized mixture was the most effective for growth. Highest survival was recorded with the Artemia diet. Larger trials performed in indoor raceways, using the homogenate diet for 10 days followed by a balanced ration, were successful before transfer to grow-out ponds.

Stable isotope ratios as naturally occurring tracers in the aquaculture food web

The natural isotopic ratio of 13 C 12 C (reported as δ C) in plant matter varies predictably among plant types. The isotopic ratio of an animal body reflects the isotopic ratio of the feed metabolized. By selecting inputs to an aquaculture feeding and/or fertilization system such that the components have significantly different δ C values, the relative meta-bolization of each of these inputs by the fish can be measured. In tank-grown Tilapia aurea (δ C = −17), supplied feed (δ C = −18) provided the carbon incorporated into the fish body even though between feedings the fish consumed large quantities of algae (δ C = −22). In penaeid (δ C = −12) grow-out ponds, δ C analyses indicated that selected components of the feed pellet (average δC = −17; components: corn and sorghum δ C ∼ −12, soybeans δ C ∼−25) were metabolized, while the benthic natural foods and other bottom organic matter (δ C = −21) provided little or no input. The value of such information for pond management and nutrition studies is clear.

Engineering Considerations in the Aquaculture of Macrobrachium rosenbergii in South Carolina

ABSTRACT A summary is presented of the progress to date on engineering experimentation involved with the culture of the fresh water prawn, Macrobrachium rosenbergii. This work is part of a Core Project on the culture of this species and includes the development of larval culture facilities, intensive culture systems, and grow-out ponds. Studies of required flow circulation in cylindrical and rectangular tanks have been conducted, as well as studies on methods of moving and aerating culture water. From the tank studies, a method of determining particle settlement in tanks of similar shape and for shrimp feed of different specific weight is discussed. Based on the research conducted in South Carolina and funded by SC Sea Grant, some considerations in hatchery design and pond harvesting are presented. The advantages of engineered ponds over conventional ponds are discussed. A proposed method of water treatment for hatcheries and grow-out ponds is also presented. Behavioral elements of the animal as they relate to engineering design are discussed where appropriate.