Melanin spots in salmon filet affects both fish welfare and economy, and it is a significant issue for the aquaculture industry. Last week, representatives from the whole value chain, gathered to try to combat the problem through cooperation and research.

A quality problem

Fish farmers, suppliers, researchers, and academia had a meeting at Bømlo to discuss the challenge from different perspectives. The gathering was part of an effort to find solutions to common issues in the industry and the meeting was facilitated together with Bremnes Seashore.

– We in NCE Seafood Innovation are devoted to facilitating dialogues throughout the whole value chain, aiming to contribute to increased innovation and sustainable growth in the aquaculture industry. At the meeting, we have tried to fill knowledge gaps and discussed possible projects which can be suitable for funding, says Björgólfur Hávarðsson, Innovation Manager in NCE Seafood Innovation.

Melanin spots are a discoloration in the filet, which appears as a dark spot. It is often discovered when the fish is slaughtered, and it is considered as a quality deviation that normally are cut off. Consequently, melanin spots leads to a lot of waste, and it costs the industry approximately two billion every year. It is, in other words, an issue for the whole industry, which needs to be solved through research and cooperation.

– Melanin spots is a big problem because it means lost income for those who are processing the fish, which also could affect their reputation in the marked. If we deliver fish with defects, it may have an impact on our reputation in the long run, adds Hávarðsson.

Complex issue

Björgólfur Hávarðsson (left) and Espen Rimstad. Photo by Peter Tubaas.

The latest news from research on melanin spots were presented by Norway`s foremost researchers on the field. Research environments have already been working with the melanin-challenge for many years. They do not agree on everything yet, but all of them are perceiving melanin spots in salmon filet as a complex problem which probably has several compound causes.

Melanin is a group of natural pigments, which is found in most living organisms. The pigment act as natural antioxidants and discoloration can have many causes. For example, the fish can produce melanin pigments to protect surrounding structures as a response to tissue damages. It is a natural part of the fish`s immune system.

– There are many hypotheses about the causes of melanin spots which is produced by melano-macrophages; either it is PRV-virus, rib fracture or vegetable oils. We have not found the main cause, yet. Therefore, we have to do more research, and it is crucial that we have a dialogue with the businesses about this, says Espen Rimstad from Norwegian University of Life Sciences (NMBU).

According to FHF, approximately every 7th fish has any form for dark discoloration in the filet. Small melanin spots can be cut off without affecting the quality of the filet, while bigger spots can lead to complaints or downgrading.  

Creative workshop

At the meeting, representatives from the aquaculture industry presented the latest knowledge on the topic from their daily operations, and how it affects the whole industry. In the workshop afterwards, potential research projects were defined.

Photo by Peter Tubaas.

– We have come so far in the research that this type of meetings has a huge potential to contribute to even more targeted research. It is super important to listen to how the industry experience this quality deviation. Also, it is interesting to hear what other researchers know and how they perceive the issue. In addition, we have had several organizations which have had something to add. It has been very useful, says Thomas Larsson from NOFIMA.

The projects will aim at contributing to increased knowledge and lay the foundation for solutions and efforts against the melanin issue.

– At Bremnes Seashore, we have worked with this for more than 20 years, and we are very pleased to invite the whole industry to Bømlo together with NCE Seafood Innovation to learn more from each other. I expect that the meeting leads to us defining the right research projects, which will fill the knowledge gaps in the biology, and through a practical approach take us closer to the goal, which is to significantly reduce the issue with melanin, says Simon Nesse Økland.

A requirement to succeed is to have enough knowledge before the industry acts. Björgólfur Hávarðsson says the industry`s long traditions for innovation, will set the grounds for success in the battle against melanin spots.

– We have solved bigger issues before, and we have developed a lot as an industry throughout the years. I think what we have started today will give us good results, he says.