Photo: Fiskeridirektoratet/FIS

Norwegian Directorate of Fisheries project for live storage of bluefin tuna

A quantity of 30 tonnes has been set aside for research and development of live stocking of bluefin tuna in 2024. 

Now seine vessels that have previously participated in the bluefin tuna fishery can apply to participate. This is reported by the Directorate of Fisheries.

Historically speaking, Norway has fished a lot of bluefin tuna, but today faces challenges related to fishing efficiency and profitability. The quality of the fish caught through traditional fishing, inefficient culling methods, and a seasonal market have led to low raw material prices and limited participation in the fishery.

Live storage of Bluefin tuna may be a possible solution to this challenging situation. Live storage allows the controlled killing of the fish and thus enables the supply of tuna to the market in line with today's requirements for quality and fish welfare.

In 2020, a pilot project started on live storage of bluefin tuna with the aim of testing and developing methodology and forming the basis for future regulations on live storage in Norway.

Construction of the transfer cage (left) and aerial view of the transfer cage while towing (right)

Through the project, several challenges have been identified that must be solved in the various phases of a capture and live storage operation. These challenges are mainly related to:

1. Identification of fish and catch control

• Improving the precision of activist monitoring systems used to detect and count tuna.
• Develop a reliable ROV (Remotely Operated Underwater Vehicle) for optical observations and equipment and capture.
• Secure infrastructure and availability on vessels to be able to handle larger catches.

2. Capture

• Optimizing the size and placement of the small-meshed panel in the groove, as well as the flutes above it.
• General improvement in catch efficiency, especially late in the season when the tuna have a higher fat content, but act collectively and with more unpredictable behaviour.

​​​​​​​3 . Transfer

• Develop a reliable camera system and optimize placement to ensure compliance with ICCAT's rules for noise transmission
• Implement a redesign of the transmission channel to improve visualization and increase transmission speed.
• Using diver-guided stereo camera systems to improve biomass estimation procedures.

4. Fish welfare and quality

• Develop protocols for monitoring welfare and quality throughout the value chain.
• Develop methods of euthanasia with a low-stress level that promote good welfare and quality, for example, diver-controlled electric or explosive harpoon methods.
• Develop cooling protocols to preserve the tuna before delivery and ensure that the tuna deliveries meet the market's quality requirements.

5. Live storage

• Find the optimal size and mesh width of the storage cage. 
• Improve delivery logistics (e.g. with more receiving points along the coast and specialized transfer/transport vessels).
• Determine the need for feeding to maintain the tunan's body weight.
• Define the limits for feeding and temperature for tuna, as well as other challenges related to live storage.

Norway has negotiated a resolution in ICCAT (The International Convention for the Conservation of Atlantic Tuna). The resolution states which requirements and obligations apply to the implementation of the pilot project on live storage in Norway. 

By 2027, Norway must have prepared a full report with the findings from the pilot project. The report is to be presented to the science committee in ICCAT, with the aim of establishing a final set of regulations for live storage in Norwegian waters.

Report

In 2023, for the first time, capture, transfer to transport cages, transport to the coast, transfer to stationary storage cages and storage of bluefin tuna  were carried out in Norway ( Sistiaga et al. 2023 ). The trial was an important step in the right direction, but there are still significant challenges, especially in terms of culling methodology, so that live storage of tuna can achieve high quality and fish welfare benefits. The requirement for the current year is to deliver a report on how far the project has come, including how much has been stored and which control mechanisms have been used.

The award requires that the Institute of Marine Research and the Directorate of Fisheries get access to the work and the research results along the way. Both institutions will assist with personnel during the trials, and with reporting afterwards. HI will provide transport cages, personnel, and methodology and equipment for stereo cameras in case of any transfer from transport cages to stationary cages.

The following criteria apply to the allocation of the quota:

• The quota set aside must be used for catching bluefin tuna, transfer to transport cages and further transfer to stationary cages, in line with current best-known practice (described in Sistiaga et al. 2023) (appendix 1). Planned major deviations from best-known practices must be described in the application.
• Applicants must have experience with locking pelagic species.
• Applicants must have participated and caught bluefin tuna  with a net since fishing started up again in 2014.
• The applicant must use an underwater camera during the transfer from net to transport cage to document the opening/closing of the channel and the number of fish transferred. In the transfer from the transport cage to the storage cage, a stereo camera must be used for length-weight estimation.
• Transport cages must be used in accordance with specifications from HI.
• The fish must be stored alive in storage cages for recovery before killing. In the event of an unforeseen event (e.g. bad weather, distance to the storage cage, mortality, etc.), the transport cage can be locked without transfer to the storage cage. Storage must take place for at least one day before slaughter.
• The applicant must present the killing method(s) which are intended to be used in the experiment and which best safeguard the welfare and quality of the fish.

Steel frame with GoPro cameras fixed to the inside of the netting in the channel.

The following requirements are placed on the vessels to be used in the experiment.

• The fishing vessel to be used must have the capacity for two observers from HI/the Directorate of Fisheries.
• The vessel must also have cabin capacity for a regional observer from ICCAT.
• All vessels associated with the experiment must be registered with the Directorate of Fisheries before Friday 7 June. This comes from the fact that all vessels that are involved in catching bluefin tuna must be reported to ICCAT by 10 June.
• The results of the experiment must be reported to the Directorate of Fisheries and the Institute of Marine Research no later than two weeks after the experiment has ended.

Left: Drone aerial view during the transfer of fish from the transfer cage (centre) to the holding cage (right). Right: Schematics with dimensions of the holding net

About the application

The application must contain an explanation of when and where the experiment is to be carried out. It must also describe how the applicant wishes to carry out the project from capture to slaughter, including a description of how culling is planned in a way that ensures good fish welfare and safeguards the quality of the fish. The application must also contain information about collaboration partners upon receipt.

The applicant must ensure that all necessary permits are available, for example from the Norwegian Food Safety Authority. The Directorate of Fisheries can assist in other application processes if necessary

Source: Fiskeridirektoratet (translated from original in Norwegian)

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