An Archimedes pump for gentle and ethical handling of Atlantic salmon in fish farms (ARGENTEA)

The main purpose of the project was to develop a new fish-friendly pump (ARGENTEA prototyp) for transport of salmon and other fish species. The pump design should allow for less crowding of the fish before pumping. This stage is found to be the most stressful part of the pumping process. If the pump protype works as intended, a more gentle method for transport of fish will be obtained for several operations, such as: - pumping of fish into well-boats - pumping of fish connected to lice and AGD treatment - pumping of fish from holding cage to slaughtery - internal transport of smolt/post-smolt salmon and trout in landbased farms During the first project stage, pump tests were conducted at NOFIMA research station at Sunndalsøra, Norway (Kottmann et al. 2022). The pumping process caused no mortality or lack of appetite in post-smolt salmon (ca. 200 g), however, stress response towards the pumping was examined in terms of biochemical stress markers in the blood, external welfare scoring as well as histological analyses of the skin. Signs of recovery from the stress response were found as soon as 24 h after pumping. Small wounds indicated a negative effect on the fish welfare, though with low severity. The current set-up of the ARGENTEA prototype fish pump required additional handling and crowding of the fish, which might have affected the stress and welfare of the fish. Due to the described problems with pumping of salmon, it was decided to test the pump protype with another aquaculture species, tilapia. In the second project stage, tests were performed with the trophical species, tilapia, at CSIR-Water Research Institute (WRI) in Ghana (Agbeko et al. 2024). A "moderate mortality" was observed (ca. 7%) which was lower compared to conventional handling/transport of tilapia (e.g. use of haw). No other biological parameters, such as fish external welfare signs and stress indicators, were sampled. The researcher concluded the following: "The machine could be used to harvest fish safely and faster than conventional methods, although scientific evidence on its ability to improve the well-being of the fish by minimizing procedural stress is yet to be ascertained".

Both in tests with salmon post-smolt and tilapia, the ARGENTEA pump pilot demonstrated obvious problems, especially connected to required additional handling and crowding of the fish before entering the pump's inlet. This affected the fish and induced stress and reduced welfare. However, pumping of tilapia resulted in less mortality compared to traditional manual handling. The described difficulties based on the tests, make it unclear to recommend the technology at this stage. More optimizing attempts would be needed to possibly commercialise the ARENTEA pilot.

Project summary The overall aim of the ARGENTEA project is to research, develop and demonstrate a new fish pump for humane handling of live SeaBass/Bream/Tilapia/shrimp inntil 2 kg in weight. The outcome will be a pump that can be used in routine handling operations during grow-out on salmon sea farms for sea lice treatment, grading and for transfer to the processing plant. ARGENTEA will cause no physical harm to salmon during handling and will not trigger the physiological stress response that impedes salmon growth and meat quality. The ARGENTEA project consists of three key milestones/deliverables: 1) finalizing the optimized design of the ARGENTEA to establish the ideal dimensions and functional parameters of the pump; 2) carrying out prototype testing and measure for biochemical markers of stress - lactate, glucose, pH, cortisol, for changes in behavior and feeding habits 3) Data from testing ARGENTEA to show the biochemical, physiological, behavioral and mortality response of salmon to being handled by an Archimedes pump, its effect on meat quality and on meat processing workflows. The project is well aligned to the EUROSTARS programme, which is designed to support research intensive SMEs with early stage high risk R&D-focused projects with a large potential market and a short route to market (< two years) which is a good characterization of this project. Besides OxyVision AS acting as project coordinator and being involved in all work packages and the development of the future commercialization plan, the consortium will consist of: GAM Manshanden Productie BV (NL), who will lead on matters covering pump design engineering and assembly of ARGENTEA, and NOFIMA (NO), who will install our machinery at their salmon farming research facilities for measuring the effect it has on salmon welfare and stress levels. The consortium brings together all necessary expertise, covering the whole value chain to improve, validate and commercialize ARGENTEA .