Significant parts of the ocean are today unavailable to industrial fish farming due to remoteness and exposure to harsh wind, wave, current and ice conditions. Presently, conventional fish farming is the second most risk exposed occupation in Norway, and operate at the limits for the fish, personnel, and equipment. In exposed conditions, the risks are magnified, making it challenging to avoid injuries, fish escapes, and mortality. Unpredictable weather and sea states lead to short operational windows and delayed or interrupted operations. Regular as well as infrequent operations are challenging. There will be postponed de-licing and longer periods of starvation for the fish.
In the Norwegian research centre EXPOSED, we have studied how exposed aquaculture operations can become robust, efficient, and safe. Exposed aquaculture operations are defined as operations on aquaculture localities where work or equipment is strongly influenced by current or weather exposure. Exposed aquaculture operations share a line of challenges, that must be addressed to be able to utilize the tricky, exposed areas along the coast and at sea.
Our studies embrace multiple methods. Some of the existing fish farms in Norway are exposed and have been studied using weather data, accident statistics, technology verification results, digital twins, interviews of personnel, etc. Other methods have been development of technology or experiments with potential materials and constructions for future fish farm concepts.
Through the studies we have identified five key challenges that needs to be solved to achieve robust, efficient, and safe exposed aquaculture operations.
The first challenge is risk in the human working environment. Exposed operations equal demanding working conditions that result in stress and occupational hazards. There is a need for coordinated action to reduce risks in aquaculture, involving industry and the various authorities.
Challenge two is demanding management and daily operations. Some farms have prolonged periods with ocean swell, and we have seen examples of farms that have been abandoned in periods. One needs to develop agreed competence requirements and design methods for robust technology and decision support.
Vessels serving the aquaculture farms also have demanding conditions, and this is the third challenge. The navigation alongside the farm needs to be gentle to fish that is crowded towards the surface and vulnerable to stream. There is a need for specialized vessel design and operational limits.
Challenge number four is fish welfare. Treating fish under rough environmental conditions inflict additional stress, with a potential for higher mortality. Crowding with large relative movements, waves, and cold air/water, represents a risk for the fish. Extreme conditions have caused mass mortality. There is a need for robust fish and adapted stocking strategies, and to understand the limitations of the fish and how to monitor its state.
The last key challenge of exposed aquaculture operations is increased risk of escaped fish. 1 of 3 escaped salmon escapes under bad weather. Extreme conditions also can cause structural failures. One preventive measure can be automated inspections.
To solve these challenges, we have approached them from different sides. We have analysed exposure limits of fish, personnel and equipment, and found techniques to model and measure environmental loads on farms, as well as exposure degree. This has lead us closer to understand how exposure and operational limits can be classified, and how exposed aquaculture operations can be robust, efficient, and safe.