Evaluation of a Recirculating Aquaculture System Research Facility Designed to Address Current Knowledge Needs in Atlantic Salmon Production

Abstract

A better understanding of recirculating aquaculture system (RAS) biosecurity is crucial for the sustainable and ethical production of Atlantic salmon smolt and post-smolt in these systems. This study described and evaluated the performance of a RAS facility for fish infection research with Atlantic salmon as the main animal model. Fish body weight, length, water quality, and system metrics from five independent experimental trials conducted between September 2020 and July 2021 were used to analyze the variation within and between treatments. Statistical power analysis was performed to determine the minimum number of fish required. The fish parameters variability showed that the inter-class correlation coefficient was on average low (0.1) and that the variation within tanks was larger than the variation between the tanks. The power analysis showed that 15 fish were required to be sampled per tank under these study conditions. Variation of water quality and system management metrics among the five experimental trials was higher compared to the variation within the five experimental trials. Moreover, the variation of the water quality parameters controlled by sensors was relatively low, whereas the parameters depending on biofilter maturation level and performance presented a very high variation. Water exchange rate-dependent quality parameters showed a similar variation value, i.e., nitrate and water turbidity. The established baseline for variability and performance presents an important reference for the design and realization of future experiments in RAS facilities. It is foreseen that the current research facility will develop new knowledge to improve the RAS biosecurity in the Atlantic salmon aquaculture industry.

Mode of Application of Peracetic Acid-Based Disinfectants has a Minimal Influence on the Antioxidant Defences and Mucosal Structures of Atlantic Salmon (Salmo salar) Parr

“…Technical information about the RAS units is provided in detail in Mota et al, 2022b ; Mota et al, 2022b . Briefly, each experimental unit consisted of a cylindro-conical fish tank (V = 0.5 m 3 ) connected to a water treatment system composed of a drum filter (micro-screen mesh size = 40 µm), a moving bed bioreactor (V = 0.2 m 3 , 750 m 2 /m 3 bio-media), a gas exchange unit (CO 2 -degasser cylinder), a foam fractionator, low pressure oxygen cone (0.6 Bar), and a temperature control unit.…”

Embracing prospects for reducing the numbers of animals used in aquaculture research

“…Research related to recirculating aquaculture systems (RAS) can often require large systems to mimic commercial scenarios (Terjesen et al, 2013), but this also means that a significant number of fish is needed to keep the system performance at optimal. Small experimental modular RAS units are alternatives to traditional experimental setup (Mota et al, 2022;Pedersen et al, 2012).…”

Determination of the Oxidative Stress Biomarkers of 8-Hydroxydeoxyguanosine and Dityrosine in the Gills, Skin, Dorsal Fin, and Liver Tissue of Atlantic Salmon (Salmo salar) Parr

“…The skin, gills, dorsal fin, and liver were collected from 234 Atlantic salmon parr (4 × 234 = 936 samples) at the Tromsø Aquaculture Research Station in Kårvik, Norway. The fish were 12.7 ± 1.5 cm long, weighed 29.3 ± 9.8 g (mean ± SD), and were maintained in a RAS during October-December 2020 [25]. Before sample collection, the fish were humanely euthanized with an overdose of Benzoak vet (ACD Pharmaceuticals AS, Leknes, Norway).…”

“…With this as background, an extraction methodology tailored to UPLC-MS/MS analysis was developed in the present study for the simultaneous determination of 8OHDG and DIY. The method was applied in 907 tissue samples (skin, gills, dorsal fin, and liver) that were collected from Atlantic salmon parr individuals reared in an experimental recirculating aquaculture system (RAS) treated with peracetic acid (to test its effect on Atlantic salmon) [25]. It is noteworthy that guanosine and tyrosine concentrations are altered in the plasma of salmon smolts when exposed to peracetic acid, rendering 8OHDG and DIY promising biomarkers of oxidative stress [26][27][28].…”