Increased knowledge about pathogenic micro-organisms and the immune system of fish against infections also contribute to safeguarding the health and welfare of farmed fish. This will also make the aquaculture industry more sustainable.
Research in the field of fish health at Nofima Marin has two main focuses:
- Obtain knowledge necessary for development of vaccines and vaccine strategies. We do this through characterisation of bacteria and viruses which cause diseases in farmed fish and through studies of the immune system of fish against different pathogenic micro-organisms
- Obtain knowledge about the effect external conditions, such as feed composition, water quality, stress and activity, have on the health and disease resistance of farmed fish
The genes and immune system of fish
We are studying genes and immune systems which are important for the ability of fish to protect themselves against diseases. Genes important for the development of lifestyle diseases are also being studied. The knowledge obtained is important for the development of vaccines, vaccine strategies and immune stimulants. In addition we acquire knowledge about how changed farming routines can contribute to more resistant fish. Further, we are developing challenge models, which are methods for testing vaccines, vaccine strategies and resistance.
- Vaccines can provide the fish long-term protection against infection.
- Immune stimulants are substances with a shorter action time. They can be added to fish feed and they activate the immune cells, making the fish more capable of eliminating viruses and bacteria.
- Changes in farming routines or feed-related factors can contribute to a more resistant fish.
In our studies we use different cell systems, cloning, characterisation and charting of gene expression and gene regulation. To do this we use functional genome research and micro array technology.
The pathogenic micro-organisms
Knowledge about the actual virus or bacteria is extremely important in order to prevent outbreaks of disease. The bacteria or viruses from outbreaks of disease are characterised to study which varieties cause disease and how widespread they are. The mechanisms that the micro-organisms use to develop disease are also studied along with the immune system of the fish and how it combats the micro-organisms - so called pathogen-host interactions.
At Nofima Marin we have shown that different variants of the bacteria Vibrio anguillarum and atypical Aeromonas salmonicida causes the diseases classical vibrosis and atypical furunculosis, respectively, in cod and that different variants of the infectious pancreatic necrosis virus (IPNv) are the cause of the disease infectious pancreatic necrosis (IPN)in Atlantic salmon.
At Nofima Marin we study the effect of experimental vaccines on cod infected with different varieties of bacteria (Vibrio, Aeromonas, Francicella etc.), and identify bacterial components which are important in order to achieve protection. The post vaccination immune responses and genes of the cod are studied and identified.
Seemingly healthy farmed salmon can carry IPNv in their immune cells, and we are studying the significance of this for the salmon's health. Different variants of viruses and intracellular bacteria can multiply in immune cells (macrophages). We are studying the mechanisms the fish have to control and regulate infections with these microorganisms.