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Hänigsen, Germany

Orellana J.,Pontifical Catholic University of Valparaiso | Waller U.,University of Applied Sciences of Saarlandes | Wecker B.,Neomar GmbH
Aquacultural Engineering | Year: 2014

The development of new species is a high priority for the diversification of the Chilean aquaculture sector. The yellowtail kingfish (Seriola lalandi) is a promising candidate for commercial production in recirculating aquaculture systems (RAS). This paper presents data on the culture of yellowtail kingfish in a marine RAS working for 488 days using artificial sea water. Growth performance, feed conversion, feeding rate, condition factor and mortality were determined for fish having an average initial weight (±S.D.) of 0.7 ± 0.2. g up to a final average weight of 2006. ±. 339.0. g. The RAS configuration (drum filter, protein skimmer with ozone, biological nitrification and denitrification, carbon dioxide removal and oxygenation) showed performance stability under the conditions assayed (low water renewal rate). Total ammonia nitrogen and nitrite-nitrogen concentration averaged 0.74. ±. 0.42. mg/L and 0.21. ±. 0.24. mg/L respectively. After installation, the denitrification reactor kept nitrate-nitrogen concentrations below 40. mg/L. Nitrate-nitrogen was totally reduced at oxidation reduction potential values between -150 and -250. mV. Water temperature averaged 22.6. ±. 1.4. °C and oxygen was maintained close to saturation levels. Carbon dioxide concentration was in average 8.3. ±. 2.47. mg/L and pH 7.5. ±. 0.1. Water renewal rate was 0.45% of the total system volume per day. The system proved the capability to maintain optimal water quality and secured animal welfare. © 2013 Elsevier B.V. Source


Buhmann A.K.,Leibniz University of Hanover | Waller U.,University of Applied Sciences of Saarlandes | Wecker B.,Neomar GmbH | Papenbrock J.,Leibniz University of Hanover
Agricultural Water Management | Year: 2015

Salt-tolerant plants can be used as biofilters for nutrient-rich saline water such as aquaculture process water. Tripolium pannonicum (Jacq.) Dobrocz. was used to determine optimal culturing conditions for an efficient biofilter performance in terms of nutrient recycling by plant uptake. This performance was evaluated by taking different parameters into account, such as biomass production, plant nitrogen and phosphorus uptake as well as physiological parameters and decrease of nitrate-N and phosphate-P concentrations in the experimental fluid. Afterwards, additional plant species known as edible were studied to follow the idea of generating valuable co-products beside the use as biofilter. It was shown that a nitrate-N concentration of at least 10mgl-1 is necessary for reasonable biomass production. A phosphate-P concentration of 0.3mgl-1 is sufficient, but higher concentrations promote the uptake of phosphate-P. The addition of iron in chelated form is required for the growth of healthy plant biomass; the addition of manganese is beneficial but not implicitly necessary. Salt concentrations lower than seawater salinity promote biomass production and nutrient uptake. The use of a hydroponic culture system is more suitable than sand or expanded clay culture if controlled conditions and nutrient recycling are desired. The five weeks experiment to compare different halophyte species in 0.24m2 tanks with nine plants each resulted in above ground fresh weight of 185 to 398g and total uptake of nitrogen and phosphorus of 0.6 to 2.1g and 0.1 to 0.4g, respectively. All tested species have potential to serve as biofilter and source for valuable co-products. A promising application is the growth of halophytic vegetable plants in marine aquaponic systems. © 2014 Elsevier B.V. Source


Waller U.,University of Applied Sciences of Saarlandes | Buhmann A.K.,Institute For Botanik | Ernst A.,University of Applied Sciences of Saarlandes | Hanke V.,University of Applied Sciences of Saarlandes | And 4 more authors.
Aquaculture International | Year: 2015

The aim of the study was to investigate the feasibility of nutrient recycling from a marine recirculating aquaculture system (RAS) for fish (European sea bass, Dicentrarchus labrax L.) through three salt-tolerant, halophyte plant species, Tripolium pannonicum (Jacq.) Dobrocz., Plantago coronopus L., and Salicornia dolichostachya (Moss.). Halophytes, illuminated by sunlight and supplemented with artificial light, were maintained in hydroponic cultures integrated in a RAS water treatment system operating at 16 psu salinity. During a 35-day experiment, 248 fishes gained 5.6 kg of weight. Total plant biomass production reached 23 kg in 14 m2 hydroponic culture area. Gain of shoot biomass was 27, 18, and 60 g m−2 day−1 for T. pannonicum, P. coronopus, and S. dolichostachya, respectively. The plants retained 7 g phosphorus and 46 g nitrogen under the experimental conditions. This was equivalent to 9 % of the N and 10 % of the P introduced with the fish feed. The edible part of the harvested plant material was microbially safe and approved for human consumption. The coupling of production in a RAS–IMTA was tested as a feasible cascading production technology for sustainable aquaculture. © 2015, Springer International Publishing Switzerland. Source

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