Raceway Tanks Research Articles

육성수조 내 북방전복, Haliotis discus hannai 치패 고밀도 중간양성 사육방식별 성장특성

The effect of different intermediated rearing method by expanding the attached floor space in order to highly density culture on the growth characteristics and survival rate of the juvenile abalone, Haliotis discus hannai, were investigated in land-based tanks. The intermediated culture methods was determined thru the shelter counts and layer for 10 month with two replicates : the single layer shelter (SLS), the double layer shelter (DLS), the triple layer shelter (TLS) and the single layer shelter under net cage (SLSNC). In addition, the culture on shallow race way tank had to set up as culture of the ditch raceway tank (CDRT) and the floor race way tank (CFRT). In the growth performance of reared abalone (initial mean shell length and weight ) at experimental tanks, that the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) to the shell length and shell breadth was not significant at each experimental tanks except SLSNC. As well as too, weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to weight was not significant at each experimental tanks except SLSNC, too. Survival rates of CDRT and CFRT was lower than those of different experimental tanks (P

Influence of tank hydrodynamics on vertical oxygen stratification in flatfish tanks

In sole (Solea spp.) culture, like in other flatfish culture, it is likely that a vertical gradient of dissolved oxygen (DO) occurs with the lower concentrations being at the tank bottom. This lower concentration at the tank bottom is a consequence of fish oxygen consumption and of the presence of the boundary layer. This fact generates lower DO concentrations in the near-bottom zone where soles are lying most of the time. The aim of this work was to study the hydrodynamic conditions that determine the oxygen gradient that occurs in the layer of water adjacent to flatfish.Three flow rates were tested in a circular tank and in a rectangular or raceway tank. For each flow rate, water velocities, boundary layer thickness and Reynolds number were calculated. Results showed that the vertical gradient of dissolved oxygen diminishes when water velocity and Reynolds numbers (Re) increase. At the fish density used in this work (11.6kgm−2), when Re decreased under 6000, a large increase in the DO gradient was observed. Guidelines are presented to determine in which situations, as defined by hydraulic parameters, Re>6000 is achieved and DO stratification avoided.The present work shows that in raceways, the flow rate required to avoid DO stratification is higher than that typically needed to maintain water quality (oxygen, ammonia-nitrogen, carbon dioxide and suspended solids). In circular tanks, it can be easier to achieve velocities that are high enough to avoid stratification with low water inlet flow rates, by adjusting the area of the water entry orifices.

Development of a wireless sensor network for algae cultivation using ISFET pH probes

We present a wireless sensor network to measure pH, dissolved oxygen (DO), and temperature for use in algae cultivation. The pH is measured using ion sensitive field effect transistor (ISFET) technology, which is more robust and has a faster response than traditional glass pH electrodes. A custom circuit drives the ISFET sensor and interfaces with an ANT wireless network system. The wireless network consists of a network hub which can service up to 8 sensor nodes and a series of relays to transmit the data to a PC. The data is logged with a custom LabVIEW program. In this work, we demonstrate operation of this network using 5 sensors (3 ISFET pH, 1 DO, 1 temp), one hub, and two relay units. The network was used to collect data for 42days from a 1600L raceway tank growing Scenedesmus dimorphus. In that time, the network did not experience any failures beyond what can be mitigated with additional battery capacity and improved construction methods. At the end of the growth cycle, the daily variation in dissolved oxygen was observed to closely track the optical density measurements.

Assessment of a Newly Designed Rearing Method Using Raceway Tanks in Juvenile Abalone, Haliotis gigantea, without Routine Bottom Cleaning

Assessment of a Newly Designed Rearing Method Using Raceway Tanks in Juvenile Abalone, Haliotis gigantea, without Routine Bottom Cleaning

Effects of water flow rate on growth rate, mortality and biomass return of abalone in slab tanks

The capital-intensive nature of land-based abalone farming demands that infrastructure be fully utilized. This study investigated whether the negative impact of high stocking density in shallow raceway tanks could be ameliorated by optimizing water flow. We quantified the effect of flow rate (87–246 L min−1) on the performance of 2-year-old hybrid abalone (Haliotis laevigata and Haliotis rubra) held at two stocking densities (11400 and 7600 tank−1). A 50% higher density yielded a 27% increase in biomass gain, despite a 10% growth reduction and 3% higher mortality. At the lower density, there was an optimal flow rate of approximately 200 L−1, at which biomass gain was 474 kg and the feed conversion ratio (FCR) was 1.31. At the higher density, biomass gain (max = 658 kg) and FCR (min = 1.41) improved linearly with increasing flow, suggesting that an optimal flow rate exists at 246 L−1 or beyond those tested. Increased oxygen availability with increasing flow is thought to have enhanced abalone performance, although flows greater than 200 L min−1 may have reduced performance at low density due to feed washout and nutrient leaching. Overall, greater financial return per tank was favoured by the combination of high stocking density and high water flow.

THREE NON-CIRCULATING HYDROPONIC METHODS FOR GROWING LETTUCE

Three non-circulating hydroponic methods for growing lettuce are described which do not require electricity, pumps or wicks. All of the nutrient solution is added prior to planting or transplanting. In the simplest system, lettuce is seeded in a tapered plastic net pot filled with growing medium and placed in a darkened, 4liter plastic bottle filled with nutrient solution with the lower 3-cm-portion of the pot immersed in nutrient solution. Plants are automatically watered, because the entire growing medium in the net pot becomes moistened by capillary action. Plant growth reduces the nutrient solution level, creating an enlarging moist air space. Meanwhile, the root system expands and continues to absorb water and nutrients. Leaf and semi-head lettuce cultivars are usually harvested at about 6 to 7 weeks after seeding. A typical expansion of this concept to a commercial scale employs a 14 cm high tank lined with polyethylene sheeting which is filled with nutrient solution and covered with an expanded or extruded polystyrene sheet resting on the tank frame. Lettuce is planted or transplanted into net pots filled with growing medium and placed in holes in the cover. Lettuce seedlings are initially watered by capillary action, and later, by direct root uptake. The crop is harvested before the nutrient solution becomes exhausted. Another modification of this method is a float-support system in long rectangular raceway tanks. Lettuce is planted or transplanted into net pots placed in a sheet of extruded polystyrene. The cover initially floats on the nutrient solution, and then, comes to rest on 2 parallel plastic pipes (10 cm diam) resting on the tank floor as the nutrient solution level recedes due to plant growth. The tank is filled with water immediately prior to harvesting and floating rafts may be easily moved to a harvesting station.

Particle removal by Northern bay scallops Argopecten irradians irradians in a semi-natural setting: Application of a flow-cytometric technique

The feeding activities of bivalve mollusks have direct impacts on suspended particles in nature. Feeding is also related to the carrying capacity of a particular system for maximal aquaculture production. Particle removal is known to be dependent upon particle characteristics, including size and type, because particle retention efficiency is size dependent, and bivalves are able to select particles actively to improve the quality of food ingested. Our goal was to quantify particle clearance by northern bay scallops of natural seston under semi-natural conditions, i.e., in raceway tanks receiving a constant flow of untreated, estuarine water. Particle clearance rate (CR) was determined based upon particle counts in tank inflow and outflow streams. A flow-cytometric technique was developed allowing rapid quantification of particles with different sizes and characterization by presence or absence of chlorophyll fluorescence simultaneously. CR varied greatly (ranging from 0.06 to 3.02 L h − 1 gDW − 1 ) among sizes and types of particles. CR of large particles was generally higher than that of the smaller particles. Under the specific conditions of this experiment, particle selectivity appeared to be ineffective because scallops did not show a higher CR on phytoplankton than on detritus. This study demonstrated the feasibility of this flow-cytometric approach to measure differential clearance of different particles in natural seston by suspension-feeding organisms.

Captive breeding and seed production of Etroplus suratensis in controlled systems

Pearlspot, Etroplus suratensis, the largest indigenous cichlid, breeds in shallow, peripheral waters and are most critically exposed to human interferences in Vembanad lake, the home ground of this species. The species exhibit a complex courtship behaviour involving pairing and nesting. Captive breeding of E. suratensis was undertaken, in specially designed artificial raceway tank, with depth situations ranging from 30 to 80 cm. Paired fishes were stocked for breeding in raceways provided with artificial spawning surfaces and breeding pits to facilitate egg attachment and 'pit caring', characteristic of the species. A total of 50 trials were carried out and in over 75 % of the cases, nest were confined to shallow depths between 12 and 45cm. The mean number of eggs within a nest was observed to be 32 cm -2 . Almost round the year breeding was possible in this controlled system and the breeding success was as high as 71 %, much higher than that in the traditional earthen pond system (60%). The fertilization rate in the confined raceway system fluctuated between 82 to 100%. When eggs were incubated allowing parental care, hatching rate varied from 63 to 99 %. Hatching of eggs occurred in 70-72 hrs at 25-27 o C. The hatched out larvae, were heavily yolked and were observed to become free swimming on the 6 th day. The fry yield under the devised system is perceptibly high (61%), as compared to that in earthen ponds (28 %). The technique devised is a reliable system for large scale production

Comparison of reproductive output, offspring quality, ovarian histology and fatty acid composition between similarly-sized wild and domesticated Farfantepenaeus paulensis

The reproductive performance of similarly-sized wild-caught ( W) and domesticated ( D) Farfantepenaeus paulensis broodstock (mean weight of 46 g for females and 29 g for males) was assessed over 30 days under standardized conditions. Wild broodstock were collected from a population off the coast of Santa Catarina, Brazil. The domesticated shrimp were first generation lines originated from the same population as the wild broodstock and were reared to 16 months of age in covered raceway tanks. Reproductive performance (e.g. data from successive spawnings) and offspring quality (egg diameter, length and survival of nauplii and protozoea stages) were recorded. Mature ovaries were sampled for the evaluation of gonadosomatic index (GSI), histological characteristics and fatty acid content. The GSI and ovarian histology indicated that full maturation was attained by both groups, but domesticated females showed a higher percentage of mature oocytes (mean ± standard deviation) ( W = 25.9 ± 7.4%; D = 35.5 ± 14.2%). Spawning performance and offspring quality were similar between wild and domesticated broodstock. Although a significantly higher number of eggs per spawning event ( W = 184,371 ± 89,011; D = 147,426 ± 79,348) were observed for wild females, the total number of eggs per female ( W = 529,065 ± 324,412; D = 421,587 ± 257,677), egg fertilization ( W = 75.8 ± 28.8%; D = 69.8 ± 27.9%) and hatching rates ( W = 52.3 ± 35.0%; D = 64.1 ± 15.7%) were similar between the two broodstock sources. Ovaries of wild females contained significantly higher levels of n−3 highly unsaturated fatty acids and, as these females produced comparatively more eggs per spawning event, it suggests that these fatty acids may have a role on ovarian development and fecundity. Overall results suggest that the reproductive performance, offspring quality, and ovarian maturation of 16-month-old domesticated F. paulensis broodstock were equivalent to that of similarly-sized wild-caught broodstock from deep-sea waters.

Raceway design and simulation system (RDSS): An event-based program to simulate the day-to-day operations of multiple-tank raceways

A software program, called Raceway Design and Simulation System (RDSS), has been built using Visual Basic for Applications in Microsoft ® Excel. The purpose of the software is to allow users to manage their raceways more efficiently by providing a tool to simulate the operation of an existing raceway or to predict conditions in a raceway under a wide variety of operating conditions. The program simulates the conditions in a system of multiple tanks that may be arranged in sets of parallel raceways with serial water flow. The user may specify the use of overflow weirs or customized oxygen injection points in order to reoxygenate the water flow from succeeding tanks in each raceway. During the course of the simulation, the user may specify the size, number, location, and price of any new fish introduced into any raceway tank. Subsequent movement of fish between tanks or removal of part or all of a cohort is tracked by the program. Input data required include properties of the influent water such as temperature, flowrate, dissolved oxygen, pH, total ammonia nitrogen, and salinity. Fish growth is predicted using these input data and stocking information that is provided by the user. Fish mortality may be specified for each tank in a raceway. In addition, the costs of food, the purchase cost of fish, and the revenue from the sale of fish are also tracked. A comprehensive user manual is included with the software that provides information on the basic operation of the program, all the programming features, troubleshooting and, the various error messages that the user may encounter when using the program.

Physiological Responses of Rock Crab Cancer Irroratus Exposed to Waterborne Pollutants

Abstract This study investigates the impact of waterborne xenobiotics on the rock crab Cancer irroratus. Male rock crabs were caged at two polluted sites for five weeks. One site was highly polluted while the other was slightly polluted mainly by metals. A control group was caged in a raceway tank supplied with clean sea water. The activity of branchial ATPases was increased in crabs exposed to pollution, presumably to compensate for the competition of metals with electrolytes and to facilitate the transport of metals out of the cytoplasm. The rock crab was characterized as having high basal levels of glutathione in the digestive gland (∼ 3500 nmol GSH equivalents/g dry weight). Exposure to waterborne pollutants failed to trigger an increase in glutathione concentration, but over time in crabs caged at the highly polluted site it elicited a 26% increment in the relative mass of the digestive gland which is an important site for glutathione synthesis. Neither cytochrome C oxidase, nor lactate dehydrogenase...

Cultivation of the brown alga Hizikia fusiformis (Harvey) Okamura: stress resistance of artificially raised young seedlings revealed by chlorophyll fluorescence measurement

Commercial farming of the intertidal brown alga Hizikia fusiformis (Harvey) Okamura in China and South Korea in the sea depends on three sources of seedlings: holdfast-derived regenerated seedlings, young plants from wild population and zygote-derived seedlings. Like many successfully farmed seaweed species, the sustainable development of Hizikia farming will rely on a stable supply of artificial seedlings via sexual reproduction under controlled conditions. However, the high rate of detachment of seedlings after transfer to open sea is one of the main obstacles, and has limited large-scale application of zygote-derived seedlings. To seek the optimal condition for growing seedlings on substratum in land-based tanks for avoidance of detachment in this investigation, young seedlings were grown in both outdoor tanks exposed directly to sunlight and in indoor raceway tanks in reduced, filtered sunlight. Results showed that young seedlings, immediately after fertilization, could withstand a daily fluctuation of direct solar irradiance up to a level of 1800 mu mol photons m(-1)s(-1), and maintained a faster growth rate than seedlings grown in indoor tanks. Detailed experiments by use of chlorophyll fluorescence measurements further demonstrated that the overnight (12 h) recovery of optimal fluorescence quantum yield (F-v/F-m) of seedlings after 1 h treatment at 40 degrees C was 98%, and the 48 h recovery of F-v/F-m of seedlings after 1 h exposure to 1800 mu mol m(-2)s(-1) was 92%. Forty-one-day-old seedlings showed no significant decrease of optimal fluorescence quantum yield at salinity ranging from 30 to 5 ppt for a treatment up to 17 h. Six-hour desiccation treatment did not have any influence on the optimal fluorescence quantum yield. Exposure to 18 mmol L-1 sodium hypochlorite for 10 min did not damage the PSII efficiency, and thus could be used to remove epiphytic algae. The strong tolerance of young seedlings to high temperature, high irradiance, low salinity and desiccation found in this investigation supports the view that mass production of Hizikia seedlings should be performed in ambient light and temperature instead of in shaded greenhouse tanks.

Cultivation of the brown alga Hizikia fusiformis (Harvey) Okamura: controlled fertilization and early development of seedlings in raceway tanks in ambient light and temperature

Commercial cultivation of the dioecious brown macroalga Hizikia fusiformis (Harvey) Okamura in East Asia depends on the supply of young seedlings from regenerated holdfasts or from wild population. Recent development of synchronized release of male and female gametes in tumble culture provides a possibility of mass production of young seedlings via sexual reproduction. In this paper, we demonstrate that controlled fertilization can be efficiently realized in ambient light and temperature in a specially designed raceway tank in which the sperm-containing water has been recirculated. The effective fertilization time of eggs by sperm was found to be within six hours. Fast growth and development of the young seedlings relied on the presence of water currents. Velocity tests demonstrated that young seedlings of 2–3 mm in length could withstand a water current of 190 cm s−1 without detachment. Culture experiments at 24 h postfertilization showed that elongation of both the seedlings and their rhizoids were not hampered by high irradiance up to 600 μmol photons m−2 s−1. However, growth was slightly retarded if cultured at a temperature of 16 ∘C compared to other culture temperatures of 22, 25 and 29 °C. No seedling detachment was observed after transfer of the young seedlings to raft cultivation in the sea after one and 1.5 months post-fertilization, indicating the feasibility of obtaining large quantity of seedlings in such a system.

Natural spawning of greater amberjack ( Seriola dumerili) kept in captivity in the Canary Islands

This paper describes results on sexual maturation and natural spawning of Seriola dumerili kept in captivity on Tenerife (Canary Islands). Wild fish captured at an average weight of 8 kg, spawned naturally and reaching an average weight of 25 kg, after 6 years in captivity in 500 m 3 raceway tanks, under natural conditions of light and temperature and fed on low-value fish. Spawning took place between April and October, coinciding with the increase in temperature from 19 to 24 °C. A total of 14 million eggs were collected in 38 spawns, with an average of 61.75% fertilization and 16.49% hatching. The greatest number and highest fertilization and hatching rates of eggs were obtained in the month of July. The greater amberjack eggs with 1.121 ± 0.032 mm diameter, hatch within 34 to 45 h, producing larvae with an average length of 3.639 ± 0.012 mm, yolk sac volume of 0.097 ± 0.015 mm 3, and oil globule diameter of 0.243 ± 0.001 mm.

Culture of turbot (Scophthalmus maximus) juveniles using shallow raceways tanks and recirculation

Traditionally, turbot (Scophthalmus maximus) have been cultured using square or circular tanks and flow-through systems. The use of an alternative culture system that combines RAS technology and shallow raceways tanks could produce similar growth rates at higher densities than conventional systems. In this study, growth and survival rates of turbot juveniles cultured in shallow raceway tanks under recirculating conditions have been evaluated. Two raceways with a 4cm water column height were set up in series and loaded each with 3654 turbot juveniles of 5.6g mean weight. Over a study period of 24 days, the average specific growth rate (SGR) observed was 1.4% and the feed conversion (FC) was 0.84g feed/g fish weight. Daily mortality rate observed was 0.09%, with an overall survival of 98%. At the end of the study, average bottom coverage reached 262% (8kg/m2). This study demonstrated that RAS technology in combination with shallow raceways allows high fish densities, improves overall productivity, decreases water pump requirements, and enhances reliability by having better control over environmental and operational parameters. Additional, longer period studies must be conducted to fully validate and approach this combined-technology to the commercial stage.

Growth of juvenile blacklip abalone ( Haliotis rubra) in aquaculture tanks: effects of density and ammonia

Grow-out density is a key factor to consider in abalone mariculture. The growth of 30–50-mm Haliotis rubra was reduced at high density. About 1800 juveniles were individually tagged and reared for 5 months in 12 gravity-fed raceway tanks at high and low density. Their growth and distribution in the tanks was monitored monthly. Density was found to affect growth directly through competition for preferred shelter space and indirectly through the degradation of water quality. Initial size was negatively correlated to growth in the first month of the experiment. Ammonia in the water was directly correlated to the number of abalone present upstream. Ammonia was negatively correlated with growth after the effects of density and initial size were removed. Growth appeared to be significantly reduced by this level of chronic ammonia exposure, which is lower than the effective level reported previously (EC 5=0.004 mg FAN/l).

Responses of Cultivated Porphyra Thalli to Water Temperature and Water Current-I. Effects of Water Temperature on the Growth of Red Alga Porphyra yezoensis from. narawaensis (Nori) Cultivated in an Outdoor Raceway Tank.

In order to examine effects of seawater temperature on the growth of Porphyra foliose thalli, outdoor raceway tanks with circulating water were newly designed, and provided the experimental condition simulating Nori cultivation farms in the sea. Frozen seed nets of Porphyra yezoensis form. narawaensis were set in the raceway tanks. During the period of the two experiments, December in 1985 and February in 1986, mean seawater temperature ranged from 8.0 to 23.4°C. Standing crop of foliose thalli increased normally at 10-17°C, but the increase rate of standing crop lessened at the temperature higher and lower beyond these limits. Visible absorption spectra of living foliose thalli, indicating concentrations of photosynthetic pigments, did not vary much within the range of seawater temperature from 8 to 20°C. The optimum seawater temperature for the growth of Porphyra foliose thalli ranged from 10 to 17°C in the raceway tanks. This temperature range confirmed results obtained through in vitro experiments but was higher than that in Nori cultivation farm.

THE TECHNICAL FEASIBILITY OF MASS‐CULTURING Artemia salina IN THE ST. CROIX “ARTIFICIAL UPWELLING” MARICULTURE SYSTEM1

ABSTRACTOf the various algae grown in the St. Croix Mariculture System, the diatom Chaetoceros curvisetus (clone STX‐167) proved to be an excellent diet for culturing Artemia nauplii and adults.The minimum cell concentration at which Artemia can efficiently remove cells has been determined and appears to be constant throughout the brine shrimp' life cycle.The cell stripping efficiency, growth rate, and survival of the different larval instar stages have been studied in function of increased stocking densities and flow rates.The results obtained in 230‐liter raceway tanks, subsequent to the initial 190‐liter tank studies, and extrapolated to a one m3 system indicate that 15 g of cysts (4/ml animal stocking density) can be converted into 8.7 kg of fresh weight adult Artemia in 14 days.