Facts about fish health
It is becoming ever more important at a time of expansive population growth, increased need for sustainable food production and a need for increased performance of marine proteins in the global diet. Profitable and sustainable production will also create new requirements for the health of farmed fish.
Facts about fish farming and health
Salmon and trout farming represent extremely effective forms of food production. Fish only need a fraction of the feed required for other "livestock" to produce a corresponding amount of meat. But production is not without its challenges.
A substantial proportion of farmed fish are lost before they can be slaughtered. There are many causes for this. Some of the wastage is due to different diseases and the handling of salmon lice, and it also appears that some fish die with no preceding illness. This may mean that these fish haven't been able to cope with the stresses they are exposed to on a daily basis.
|Some key figures from 2015:||Salmon||Rainbow trout|
|Number of individual fish released to the sea||287 mill.||15.7 mill.|
|Number of localities with permits||974 mill||
This means financial challenges for the industry through less production, time and resources. Just as important are the consequences for animal welfare and the reputation of the industry. For all fish farmers, focusing on fish health and fish welfare is necessary for sustainable production, and a good reputation for salmon as an international brand.
Can we increase production five-fold?
SINTEF and collaboration partners reported in 2012 on the possibility of increasing production of Norwegian farmed fish five-fold by 2050. Such growth is desirable from the perspective of the authorities from both a climate perspective and with regard to the economic potential this involves, but this vision has been put on hold.
Growth on this scale means annual growth of between 4 and 5 per cent. However, the reality is that the last few years have seen growth stagnate, and at the end of April 2016, the biomass in the sea was 4 per cent lower that at the same time the year before. This is to be seen in connection with the profound challenges the industry has with salmon lice.
Fish health is crucial
To protect wild salmon against increased pressure of infection from aquaculture, the authorities have introduced regulations regarding how many lice a fish farm can have. The fish must be treated if this number is exceeded, which causes stress and can result in increased mortality. Prevention of disease is therefore the key to achieving sustainable and profitable production of salmon with good animal welfare and the least possible use of medications.
Fish health is a result of a number of factors such as hereditary factors, the environment, density, pressure of infection, and nutrition. The responsibility for healthy fish rests first and foremost with the fish farmer. But health professionals such as veterinarians and fish health biologists, and everyone involved aquaculture nutrition are important contributors to fish being as healthy as possible.
Before the number of concessions and the amount of fish can be increased, two key challenges connected with production have to be solved: wastage must be reduced and the number of salmon lice must be kept to an acceptable level to prevent increased infection pressure for wild salmon.
How to avoid disease?
Preventive health care is all about increasing awareness of health and providing the foundation for the most effective possible prevention of disease. By changing the environmental and living conditions, we can reduce the occurrence of risk factors.
In order to achieve effective prevention of disease, it is important to work holistically with ongoing research and development regarding new vaccines, strategic breeding and optimisation of feeding.
If we manage to prevent infectious disease in just one fish farm, this will also in theory lead to less infection pressure on fish in surrounding cages and thereby reduce infection pressure overall.
One example of preventive health care
To work preventively with health care is a dynamic process. Salmon farming is an industry in constant development. New challenges will emerge as the conditions surrounding fish change. New forms of farming and new diseases require that salmon must be continuously adapted to the new conditions.
One example is the growing proportion of large smolts that are being produced. Research indicates that larger smolt can better tackle the transition to the sea, but this requires increased knowledge regarding requirements with respect to the design, handling and environmental conditions in the hatcheries. This effects not just fish farmers, but is also a challenge for other participants in the industry.
BioMar contributes with a feed that is adapted to recirculation farms that are kinder to the living biofilters that are used for cleaning the water. We thereby contribute to keeping the living conditions the best they can be.