Evaluation of Dicentrarchus labrax Meats and the Vegetable Quality of Beta vulgaris var. cicla Farmed in Freshwater and Saltwater Aquaponic Systems

Abstract

Abstract:The purpose of this study is to exploit the euryhaline nature of commercially attractive species for their cultivation in freshwater aquaponic systems. This approach may increase the profitability of aquaponic production in coastal countries where the consumption of marine fish is traditional and of commercial relevance. For this purpose, juvenile European sea bass (Dicentrarchus labrax) were reared in an aquaponic freshwater (AFW) system and an aquaponic saltwater (ASW) system (salinity 20 ppt), in combination with chard (Beta vulgaris var. cicla) seedlings, a salt tolerant plant. At the end of the trial, nitrate and phosphate concentration in water significantly increased in the ASW system, suggesting that the ability of B. vulgaris to absorb these substances was limited by salinity. Total reflection X-ray fluorescence spectrometry revealed that the concentration of some oligoelements such as Fe remained lower with respect to the concentration in the freshwater hydroponic solution, in both AFW and ASW. FTIR-Fourier transform infrared spectroscopy on plants showed that growth at high salinity affected their lipid content. In the case of fish, freshwater had no effects on mono-and poly-unsaturated fatty acid profiles, although saturated fatty acids were significantly decreased in D. labrax reared in AFW. Our results demonstrates that it is possible to increase aquaponic profitability by farming D. labrax juveniles in an aquaponic freshwater system together with Beta vulgaris, obtaining good quality products.

An Experimental Brackish Aquaponic System Using Juvenile Gilthead Sea Bream (Sparus aurata) and Rock Samphire (Crithmum maritimum)

“…In total, six autonomous aquaponic systems with a total volume of 135 L per system were constructed. Each treatment consisted of three rectangular fish tanks (30 cm × 60 cm × 30 cm), three hydroponic cultivation tanks as described by Somerville et al and Nozzi et al [3,25] as a raft method cultivation, thus, creating a volume of 54 L for the fish and a cultivation area of 1800 cm 2 for the plants. Each aquaponic system was supported by a biological sump filter (30 cm × 30 cm × 30 cm) a total volume of 27 L, which had a significant contribution in the nitrification process by increasing filter efficiency.…”

“…Thus, the use of brackish water in aquaponic systems that include plants that are naturally adapted to salinity (halophytes) is very important [24]. Aquaponics with brackish water may combine the rearing Mediterranean euryhaline species of fish, such as juvenile sea bream or sea bass, in combination with a wide variety of Mediterranean plant organisms, such as algae [23] or halophytes (e.g., rock samphire), which exhibit high commercial and/or nutritional value [5,25]. Published research on freshwater aquaponic systems is limited to only a few studies [5,22,25,26].…”

“…Aquaponics with brackish water may combine the rearing Mediterranean euryhaline species of fish, such as juvenile sea bream or sea bass, in combination with a wide variety of Mediterranean plant organisms, such as algae [23] or halophytes (e.g., rock samphire), which exhibit high commercial and/or nutritional value [5,25]. Published research on freshwater aquaponic systems is limited to only a few studies [5,22,25,26]. In addition, published research data available for sea water aquaponics are scarce, while the corresponding studies in brackish aquaponics are minimal [5,24].…”

Evaluation of Marine Synechococcus for an Algal Biorefinery in Arid Regions

“…Additionally, the fact that this particular strain can grow in high salinity water and high ambient temperatures presents opportunistic synergies to tap into whereby integrated aquaponics systems can be designed such that fish or shrimp farming effluents can serve as irrigation sources for growing halophytes and algae [42,43]. Theoretical knowledge of aquaponic system involving fish and vegetables is available, however the novelty lies in adding salt tolerant algae to this system while trying to utilize saline water [44][45][46]. Growth of the local Synechococcus strain in several nutrient media compositions was also investigated.…”

Lettuce (Lactuca Sativa) Growth Performance in Saltwater, Soil and Aquaponic System

“…Recently, the demand for seafood products on the global market is rising especially in Asian countries due to the increase in affluence and appreciation of the health benefits of seafood. Saltwater aquaponic system had been studied as an extension of aquaponics to grow seafood and high salt tolerance crops [8]. This study aimed to compare lettuce seeds germination and plants growth in soils and aquaponics, and lettuces growth with and without salt treatment in freshwater and saltwater aquaponics.…”