Predictive fish health under changing environment

New farming techniques, alteration of the rearing conditions and climate changes are expected to significantly impact the stress status in salmon. Although we have a good knowledge about different stressors, little is known about their compounding impacts (e.g. temperature vs pH vs densities vs handling) as well as experimentally verified strategies to mitigate the effects of certain stressors.

Predictions and modeling suggest that future climate scenarios and intensified farming practices will likely increase the frequency and occurrence of diseases and pathogens in aquaculture systems. In CtrlAQUA, we have a strong focus on understanding how to improve the overall health status of fish in closed-containment systems by strengthening the biological barrier functions and enhancing resistance to pathogens and stress. In land-based closed-containment aquaculture systems for salmon today, several strategies are being considered including recirculating aquaculture systems with brackish water or flow-through systems with full-strength seawater.

Rearing fish under high density is an advantage to reduce production costs provided that welfare and health are not adversely affected. Regardless of the technology in future fish farming – open net-pens, closed containment systems or recirculation systems on land, it is projected that there will be serious biological challenges in the aquaculture sector.

When environment and rearing systems are changing, we need to develop techniques and strategies that will reveal the condition of the fish and help us evaluate their general health status. A basic understanding of host-pathogen interactions and barrier functions, techniques for efficient and effective vaccination and development of environment-friendly, non-medicinal methods not involving stressful or harmful handling of the salmon, are needed as well as in vitro systems that do not involve huge amounts of research animals are still needed.

The overall aim of the project is to expand the knowledge on how the environment affects the biology of farmed fish and develop robust systems that may be used to screen and evaluate the impacts of the challenges related to changing environment.

Specifically,

1. Expand our knowledge regarding the stress status and preventive measures in salmon
2. Understand the mechanisms behind the interactions between bacteria and immunity in salmon and cleaner fish
3. Develop in vitro systems for mucosal and other immune-relevant tissues in salmon, cleaner fish and cod
4. Investigate spectroscopy as an application to evaluate fish health