Catch Handling Guide
The Sport Fishing Advisory Board has prepared the following guidelines for the safe handling of tuna:
As tuna tend to be warmer in temperature than the water they came from, they require special care and consideration when it comes to handling. Different procedures need to be deployed than those utilized for Salmon, Halibut and other ground fish species.
Tuna tend to contain higher amounts of histidine in their flesh. Histidine is a type of amino acid that is converted into histamine by bacterial enzymes once the fish is deceased. The rate of this conversion is increased by temperature, so it is important that all tuna are handled properly to avoid spoilage.
The consumption of fish containing high levels of histamine can result in scombroid poisoning. Scombroid or histamine poisoning often resembles an allergic reaction, and most victims recover within 24 hrs. However, on rare occurrences, scombroid poisoning has resulted in death.
The best way to reduce the risk of scombroid poisoning is to chill the tuna quickly after being caught.
The Bamfield Tuna Shootout Advisory Board recommends following the C.I.F.P. process, used by many of the top Canadian tuna guides.
After bleeding, chill fish in slush ice (a mixture of two parts ice and one part sea water) before icing. Do not allow catch to lay on deck. Tuna will chill much quicker in a slurry of ice and water than on just ice by itself. This is because heat transfer from the fish occurs faster in a liquid than just ice. Remember to add ice periodically as it melts. This will also help you get the most out of your supply of ice.
Remember to take enough ice to preserve your catch. Once the tuna has reached a core temperature of 10 degrees Celsius (use a meat thermometer) or less, pack in flake ice for no more than 5 days prior to processing. Fish should be held at 4 degrees Celsius or less. Fish should be iced in single layers with ice between each layer. Add ice to the top of the cooler or hold (cap icing).
If you are unable to process your catch immediately, freeze your catch as soon as possible.
Now that you have caught, chilled and cared for your tuna, the next step is to properly package your catch for long term preservation, which you can either do yourself or have a licensed processing facility do for you.
The two most common DIY processing techniques are vacuum-packing and canning. To vacuum-pack your tuna, you should fillet, vacuum-pack, and freeze your tuna immediately. To can your fish,we recommend you check the CFIA and USFDA websites for proper practices and techniques.
Always keep fish cold until you process the catch yourself or deliver it to a processing facility. Remember to check with the processing facility for their specific guidelines, as many companies have their own specific policies which may vary from different service providers.