Using AI to combat the development of winter wounds

Winter wounds are caused by bacteria, such as Moritella viscosa, that thrive in water temperatures below 7–8°C. The bacteria infects skin damages and wounds in the fish. Combined with reduced metabolism, a weakened immune system, and a thinner protective mucus layer – all effects of cold water – the conditions become ideal for development of winter wounds, also known as winter ulcers.

From lice treatments to winter wounds

The risk of fish developing winter wounds drastically increases during cold periods if the fish already has existing skin damage and injuries. One of the major reasons for injuries on the fish is manual handling and mechanical lice treatment. These procedures can damage the fish’s mucus layer, cause scale loss – and sometimes open wounds. When sea temperatures are low enough, initial injuries can be infected by bacteria, causing development of serious winter wounds.

Using Aquabyte LICE, farmers receive daily, accurate updates on lice levels without any manual handling of the fish.

The value of automatic lice counting

Using automatic lice counting systems with camera and AI technology that reduce the need for manual handling is an important measure to lower the risk of fish injuries that can become infected and develop into winter wounds. Combined with modern systems’ ability to provide accurate lice forecasts weeks in advance, farmers can identify trends early, plan delousing treatments more effectively, and often reduce the total number of treatments required during a production cycle. Fewer treatments mean less handling, which in turn leads to fewer injuries and a reduced risk of bacterial infection.

“Manual lice counting and mechanical delousing put significant strain on the fish. We know that manual counting leads to higher mortality rates, and that mechanical delousing damages the fish’s protective mucus layer and can result in scale loss. In the worst case, fish develop open wounds – which significantly increases the risk of winter ulcers.”

Reinhard Fellner, Director of Insight & Customer Success at Aquabyte

New production technologies, such as closed pens, significantly reduce fish exposure to lice – but not to cold water conditions where bacteria can contribute to winter wounds.

Shielding technologies

New shielding production technologies – such as submerged, closed/semi-closed pens, and lice skirts – can significantly reduce lice exposure by shielding fish from the environment. The goal of these technologies is to reduce the need for manual handling and lice treatments, addressing key causes of skin damage that can later develop into winter wounds.

However, even in shielded systems, fish can still develop skin damage - and they remain exposed to cold water conditions where bacteria thrive. At the same time, these shielding technologies can make it more challenging for farmers to monitor fish health before and during cold periods.

The value of automatic welfare monitoring

Automatic welfare monitoring using cameras and AI allows farmers to keep a close eye on the fish no matter production method used. Fish welfare can be monitored before and after lice treatments, and throughout the entire production cycle, providing farmers with up-to-date insights on fish welfare issues that can lead to winter ulcers:

• Do the fish have wounds?
• Are the wounds healing or worsening?
• Is overall fish welfare improving or declining?

In shielding technologies, where the fish is out of sight and traditional monitoring methods are limited, obtaining these detailed levels of insight is very difficult without camera and AI technology.

Aquabyte WELFARE provides farmers with up-to-date insights into fish health and is an important tool when evaluating key decisions related to treatment and delousing strategies.

“With AI-based monitoring, farmers gain precise, continuous insight into important parameters – such as lice levels, welfare and weight – without removing fish from the pen. This reduces heavy physical labour during winter, minimises stress for the fish, and lowers the risk of injuries.”

Jon Bjarte Bruland, Customer Success Associate at Aquabyte

The values of AI technology - summed up

Using automatic lice counting reduces the need for manual handling of fish and can, in many cases, reduce the number of delousing treatments required during a production cycle. The result is fish with fewer injuries that might develop into winter wounds.

Continuous welfare monitoring using AI enables early detection of developing wounds and injuries – whether caused by handling, treatments, stocking density, or obstructions in the pen – allowing farmers to intervene before issues escalate: lice treatment strategies can be optimised based on fish condition, and the use of functional feed and probiotics can support the fish’s natural immune response and faster healing.
Fish with less wounds and injuries have less risk of developing winter wounds when exposed to bacteria. 

Camera and AI technology provides farmers with detailed insights into both lice levels and welfare status, allowing them to take action to help prevent fish from developing winter wounds.

AI for better strategic production decisions

Having accurate, up-to-date insight into the status of each pen ahead of the peak winter wound season also enables more strategic production decisions. Based on lice levels, welfare indicators, and weight data, farmers can make more confident decisions about which pens should be harvested early and can remain in production during the colder period, when the risk of winter wounds increases. 

These are critical decisions, and choosing the wrong pens can have significant consequences for both fish welfare, superior rates, and, ultimately, the profitability of the operation.