Comparision of two water agitation methods in seaweed culture tanks: influence of the rotating velocity in the seaweed growth and energy requirement

Integrating seaweed production into land-based marine fish-farms allows removing dissolved nutrients and improves the sustainability of the coastal marine aquaculture. Free-floating seaweed culture in tanks, with suspension provided by tumbling, is the most usual cultivation technique used in this kind of facilitiesPostprint (published version

Influence of tanks liner material on water quality and growth of Clarias gariepinus

Three tank liner materials: polyvinylchloride (PVC), polyethylene and polyester were evaluated in a 93 days experiment for their influence on culture water quality and growth performance of Clarias gariepinus. Fish of average weight of 5.03±0.21g were stocked at 375 per m3 in tanks lined with the aforementioned materials. Fish were hand fed twice a day. Growth performance and water quality parameters were measured using standard methods. Average temperature of 25.09±1.14OC was recorded in the tanks. Dissolved oxygen with the highest mean value of 5.41±0.96 mg/l was recorded in polyethylene lined tanks while the highest mean alkalinity value of 110.38±2043mg/l was obtained in polyester lined tank .Fish cultured in PVC lined tanks recorded the highest mean daily growth rate of 4.87±3.87g while polyester lined tanks recorded the lowest mean value of daily growth rate of 2.95±2.08g. Highest mean food conversion ratio was recorded in PVC lined tanks with the value of 1.59±0.70. Highest mean weight of 22.59±1.56g was obtained in PVC lined tanks while the least mean weight of 15.41±1,11g was obtained in polyethylene lined tanks. Fish cultured in PVC lined tanks had better growth performance when compared to other tanks liner materials. It would be beneficial with respect to fish growth and culture water quality, to use polyvinylchloride materials in lining fish culture ponds and rearing tanks.Keywords: Aquaculture, Liners, Fish Farming, Tank, Clarias gariepinu

Influence of tanks liner material on water quality and growth of Clarias gariepinus

Three tank liner materials: polyvinylchloride (PVC), polyethylene and polyester were evaluated in a 93 days experiment for their influence on culture water quality and growth performance of Clarias gariepinus. Fish of average weight of 5.03±0.21g were stocked at 375 per m3 in tanks lined with the aforementioned materials. Fish were hand fed twice a day. Growth performance and water quality parameters were measured using standard methods. Average temperature of 25.09±1.14OC was recorded in the tanks. Dissolved oxygen with the highest mean value of 5.41±0.96 mg/l was recorded in polyethylene lined tanks while the highest mean alkalinity value of 110.38±2043mg/l was obtained in polyester lined tank .Fish cultured in PVC lined tanks recorded the highest mean daily growth rate of 4.87±3.87g while polyester lined tanks recorded the lowest mean value of daily growth rate of 2.95±2.08g. Highest mean food conversion ratio was recorded in PVC lined tanks with the value of 1.59±0.70. Highest mean weight of 22.59±1.56g was obtained in PVC lined tanks while the least mean weight of 15.41±1,11g was obtained in polyethylene lined tanks. Fish cultured in PVC lined tanks had better growth performance when compared to other tanks liner materials. It would be beneficial with respect to fish growth and culture water quality, to use polyvinylchloride materials in lining fish culture ponds and rearing tanks.Keywords : Aquaculture, Liners, Fish Farming, Tank, Clarias gariepinu

Deliverable 2: Report on the production of GIF by turbot, the effects on growth performance of turbot of local GIF production within RAS and the presence of GIF at commercial farm level

One of the working hypotheses of this project is that growth retardation of turbot cultured in recirculating aquaculture systems (RAS) is caused by the accumulation of growth inhibiting factors (GIF) produced by the turbot themselves in the culture water. Our first goal was to demonstrate the production of growth inhibiting factors by turbot following the methodology of Yurl and Perlmutter. A series of successive experiments was performed. Extracts from turbot culture water were tested for GIF presence in early life stage tests using eggs and larvae and small scale growth trials with juveniles. Our second goal was to demonstrate the transfer of GIF between tanks. Four experiments involving the integration of experimental tanks in a farm scale setting were performed. Our third goal was to demonstrate the presence of GIF at commercial farms. Two juvenile growth trials were performed

Honeycomb fiber-reinforced polymer sandwich composites for development of aquaculture raceway systems

It is argued that the utilization of impaired mine waters abundant in WV and other mid-Appalachian states for fish culture can substantially increase aquaculture economic development. The primary limitation to the effective utilization of discharged waters is the lack of suitable fish culture tanks that can be easily installed in rugged terrains surrounding mine water treatment plants, where cast-in-place concrete tanks cannot be constructed. Therefore, Fiber-Reinforced Polymer (FRP) sandwich materials offer an economical option for production of light, transportable and durable fish culture raceway systems. This study is concerned with the development and evaluation of prototype fish culture tanks using a Honeycomb FRP, termed HFRP, sandwich panel with sinusoidal core geometry, which is produced by Kansas Structural Composites Inc., (KSCI) by a contact-molding process.;Based on defined functional requirements, a raceway system consisting of staggered tanks is designed, and each tank has a longitudinal partition wall to carry out parallel aquaculture studies. (Abstract shortened by UMI.)

Economic feasibility of composite fish culture in leased-in village tanks of Kanyakumari district: an invesment analysis

Kanyakumari district belonging to the high rainfall zone has resource advantages for composite fish culture in the leased-in village tanks. There are more than 400 fish farmers operating in leased-in tanks following composite fish culture under the FFDA programme. To estimate the economic feasibility and financial viability of the enterprise, the present study was taken up. 38 fish farmers selected from the district provided the necessary information like capital investment, costs and return and constraints. The data collected were analysed and a farm nearest to the average farm situation was taken as the representative farm. Investment criteria like PayBack Period (PBP), Simple Rate of Returns (SRR), Net Present Value (NPV) and Benefit Cost Ratio (BCR) were estimated taking into account a period of 10 years, the period for which the village tanks are leased-out to fish farmers under the FFDA programme. The analysis indicated the profitability of composite fish culture in village tanks in the district and the results are discussed with recommendations

Assessment of carotenoid production by Dunaliella salina in different culture systems and operation regimes

The effect of operation regime and culture system on carotenoid productivity by the halotolerant alga Dunaliella salina has been analyzed. Operation strategies tested included batch and semi continuous regime, as well as a two-stage approach run simultaneously in both, open tanks and closed reactor. The best results were obtained with the closed tubular photobioreactor. The highest carotenoid production (328.8 mg carotenoid l−1 culture per month) was achieved with this culture system operated following the two-stage strategy. Also, closed tubular photobioreactor provided the highest carotenoid contents (10% of dry weight) in Dunaliella biomass and β-carotene abundance (90% of total carotenoids) as well as the highest 9-cis to all-trans β-carotene isomer ratio (1.5 at sunrise).Comisión Interministerial de Ciencia y Tecnología IFD 1997-1780IFAPA CO3-125Plan Andaluz de Investigación CVI13

Survey of large circular and octagonal tanks operated at Norwegian commercial smolt and post-smolt sites

AbstractA survey was conducted to determine the geometry, operating parameters, and other key features of large circular or octagonal culture tanks used to produce Atlantic salmon smolt and post-smolt at six major Norwegian Atlantic salmon production companies. A total of 55 large tanks were reported at seven land-based hatchery locations, i.e., averaging 7.9 (range of 4–12) large tanks per land-based site. In addition, one 21,000m3 floating fiberglass tank in sea was reported. Culture volume ranged from 500 to 1300m3 for each land-based tank. Most tanks were circular, but one site used octagonal tanks. Land-based tank diameters ranged from 14.5 to 20m diameter, whereas the floating tank was 40m diameter. Maximum tank depths ranged from 3.5 to 4.5m at land-based facilities, which produced diameter-to-average-depth ratios of 3.6:1 to 5.5:1m:m. The floating tank was much deeper at 20m, with a diameter-to-average-depth ratio of only 2.4:1m:m. All land-based tanks had floors sloping at 4.0–6.5% toward the tank center and various pipe configurations that penetrated the culture tank water volume at tank center. These pipes and sloping floors were used to reduce labor when removing dead fish and harvesting fish.Maximum flow ranged from 3 to 19m3/min per land-based tank, with 400m3/min at the floating tank, but tank flow was adjustable at most facilities. Land-based tanks were flushed at a mean hydraulic retention time (HRT) of 35–170min. Maximum feed load on each land-based tank ranged from 525 to 850kg/day, but the floating tank reached 3700kg/day. Almost half of the large tanks reported in this survey were installed or renovated since 2013, including the three tank systems with the highest flow rate per tank (greater than 17.6m3/min). These more recent tanks were operated at more rapid tank HRT’s, i.e., from 34.8 to 52.5min, than the 67–170min HRT typical of the large tanks built before 2013. In addition, flow per unit of feed load in land-based tanks that began operating before 2010 were lower (19–30m3 flow/kg feed) than in tanks that began operating later (33–40m3 flow/kg feed). In comparison, the floating tank operates at a maximum daily tank flow to feed load of 160m3 flow/kg feed, which is the least intensive of all tanks surveyed. Survey results suggest that the recently built tanks have been designed to operate at a reduced metabolic loading per unit of flow, a tendency that would improve water quality throughout the culture tank, all else equal. This trend is possible due to the ever increasing application of water recirculating systems

Atlantic Drift: Supranational and American Think-Tanks in Comparison

While there has been a significant amount of scholarship on think-tanks in the United States, attention to these same organizations in the European Union has been scant. In particular, there has been a dearth of scholastic treatment of think-tanks operating with an EU-level mandate within Brussels, which this study has termed supranational think-tanks. This study pursued an original comparative analysis between both of these diverse think-tank models. In particular, the principal research questions guiding this study concern the differences that exist between these think-tank models and, more importantly, why these divergences have manifested. In terms of their differences, it was revealed that American and supranational think-tanks diverge through three principal aspects: their roles, priorities, and main constituencies. In offering an explanation as to why these differences have emerged, this study pinpointed two principal variables: institutional credibility and political culture. From an institutional perspective, supranational think-tanks have been afforded an inherent credibility by the institutions of the EU, and have therefore been able to direct their resources and efforts to those activities and outputs in which they have a comparative advantage and can add value to the EU policy-making community. American think-tanks, on the other hand, do not have such institutional credibility, and therefore need to provide evidence of their credibility to their main constituencies, especially in making their case for funding. Further, for American think-tanks, an adversarial and individualistic political culture has informed the ambit of think-tank norms and activities, while the consensus-driven and collectivist political culture of Europe has similarly impacted supranational think-tanks

Cultivation of western white shrimp (Litopenaeus vannamei) using underground brackish water

We assessed the possibility of western white shrimp culture using underground brackish water in Bushehr province, Iran. In July 2008, white shrimp post larvae were stocked in 4 fiberglass tanks, each with a capacity of 3.8m2 . Two tanks were filled with brackish water 35ppt in salinity and two others with underground brackish water 4ppt in salinity. Tanks were situated outdoor and aerated nonstop using a central aerator. The stocking density was 58ind/m2 and the culture period was 90 days. Shrimps were fed with commercial diet by two trays, 80 cm in diameter in each tank. Water exchange was carried out two times a week. During the culture period, the weights of 40 ind. of shrimps were measured every 15 days. At the end of culture period, mean weight of 21.34g and 18.22g, survival of 92.25% and 97.75%, mean production of 1.11 and 1.03kg/m2 and food conversion ratio of 1.20 and 1.28 were recorded for 34ppt and 5ppt salinities, respectively. Statistical analyses showed no significant difference between treatments