“Salmon farmers have always cared about fish health and welfare,” says Solveig Nygaard, Global Fish Health Manager at Grieg Seafood.
A veterinarian by trade, she has been working to safeguard the health and welfare of both terrestrial and aquatic animals for more than 35 years. She knows a thing or two about fish health and welfare.
“The founders of the industry kept an eye on the fish and tried to adjust production to improve welfare. However, a lot was still unknown territory at that time. We have come a long way since the early days,” Solveig says.
While terrestrial animals have been studied in detail for decades, there is still much to learn about aquatic animals. Naturally, studying fish in the ocean is more difficult than studying animals on land. Still, scientific knowledge is progressing, especially when it comes to fish health.
Pursuing fish welfare indicators
However, it has proven more difficult for the research community to find objective indicators on fish welfare. To improve in this area, the Norwegian Institute of Marine Research, the Norwegian Veterinary Institute, the research institute Nofima, Nord University and the University of Stirling initiated the Fishwell project in 2015. The initiative brought together knowledge and best-practice, and outlined welfare indicators for fish. Grieg Seafood participated in the project.
“Fishwell is a good start, and provides an overview of what we know so far. However, it does not define when an impact is acceptable and when it is harmful. That is because the limits differ at various stages of the salmon lifecycle. More research must be done,” says Anne Tjessem, a fish health biologist and Fish Health Manager at Grieg Seafood Finnmark.
In fact, much is being done to drive advances in this area, such as the use of camera technology to monitor the behavior of each individual fish.
Grieg Seafood Finnmark has also endeavored to develop objective welfare criteria at the individual pen level, since this is the unit most commonly used as the basis for various farming operations.
“Based on Fishwell, our own experiences, and the specific conditions in our region, we have established objective scoring criteria for aspects like appetite, water quality, observations, the presence of parasites or predators, and the number of fish with atypical behavior and injuries. Our aim is to work more systematically to gain a better understanding of what is normal, learn to recognize early warning signs, and understand what causes problems. The scores for each pen provide more objective grounds for our mitigation efforts,” Anne explains.
Grieg Seafood is working to develop and implement these criteria in all regions, both at our sea farms and during the freshwater phase.
Expressing natural behavior
The Fish Health Manager and her team aim to enable the salmon to express their natural behavior as much as possible. A Grieg Seafood sea-pen contains at least 97.5% water, leaving plenty of room for the salmon to swim around.
“As far as we know today, salmon have a good life when they can swim around in a shoal, which they have every opportunity to do in our pens. This type of behavior, combined with a good appetite, indicates a high level of fish welfare. Our job is to minimize the risk of diseases and stress,” says Anne.
The situation for the cleaner fish used to eat the sea lice which have latched onto the salmon, thereby helping to keep lice levels low, is more demanding.
“Cleaner fish need a lot more help from those of us who have them in our care. They need places to hide and rest, and their own tailor-made feed. These are new species to aquaculture, and we need to learn a lot more about how we can improve their welfare. In the meantime, however, we have created artificial kelp forests in our pens, to provide hiding places for them,” Anne explains.
Prevention – the key to all good things in salmon farming
Prevention is an increasingly hot topic in the salmon industry.
“Enabling the fish to live, grow, and thrive, and avoiding treatments and handling, is how we provide the best fish welfare. Preventative measures are the key to all good things. We aim to prevent and protect our fish from the dangers that exist naturally in the marine ecosystem, like diseases, sea lice, low oxygen levels, or harmful algae,” says Solveig Nygaard.
Various preventative health and welfare measures are in place throughout the salmon’s lifecycle. Their aim is to help each fish resist diseases and cope with sub-optimal environmental conditions without treatment. Such measures include the selection of roe with specific qualities to make them resist sea lice and diseases, feed customized for the various stages of the salmon´s lifecycle, and vaccinations targeting specific diseases.
“The world is now experiencing how important vaccines are to combat Covid-19. It is the same for both animals and fish – vaccines against viruses and bacteria have been a vital way to improve animal health and welfare for decades. The entire Norwegian salmon industry, producing 16 million meal portions of salmon per day, hardly uses any antibiotics at all. We have the vaccines to thank for that,” Solveig explains.
As far as we know today, salmon have a good life when they can swim around in a shoal, which they have every opportunity to do in our pens. This type of behavior, combined with a good appetite, indicates a high level of fish welfare. Our job is to minimize the risk of diseases and stress.
Reducing mortality from treatments
While preventative methods in salmon farming are the most ethical, sustainable, and cost-effective, it is important to have various types of treatments in our tool box if biological conditions become too challenging. Should the pressure of sea lice rise too high, reducing the effect of the various preventative methods, salmon farmers must apply treatments to their stocks in order to protect wild salmon populations.
“Our goal is to avoid treatments. However, if we do need them, they should ideally have a low impact on both fish welfare and the environment,” says Solveig.
In recent years, the salmon farming industry has rapidly reduced the use of medicinal delousing treatments. Instead, farmers have applied mechanical treatments, applying fresh water or warm water to remove sea lice from the salmon. While these methods were initially well received as environmentally friendly, the first generations of the technologies were not as kind to the fish.
“The rate of mortality caused by mechanical treatments has been too high. However, we are now seeing improved solutions, and the mortality rate from these types of technologies is falling. New solutions in our industry should solve the challenges they are intended to, but they must also protect fish welfare,” the experienced veterinarian emphasizes.
Increased focus on the freshwater phase
Solveig has plans in place to improve fish health and welfare throughout the Grieg Seafood Group. Going forward, more attention will be paid to the freshwater phase, to ensure that the smolt are as robust and healthy as possible before they are transferred to our sea farms. Solveig has already started trials with microbacterial reinforcement, adding “good” bacteria to the freshwater phase to explore whether they can make the salmon more robust.
Learning how to optimize welfare in a production cycle based on post-smolt fish is also high on the agenda. For example, how should the vaccine program be adjusted to suit post-smolt fish transferred to the sea at different times of the year? And how do light conditions and salinity at freshwater facilities impact salmon health and welfare in the sea farms?
“What we know for sure is that independent and scientific knowledge, research, and development is what will move us forward,” says Solveig. “There is already a lot of collaboration between research institutes and the industry on how to improve fish health and welfare. That must continue.”