PLANNING
Plan to clean the fish within an hour of catching it.
Bleeding
To preserve freshness it is important to remove as much blood as possible from the fish before chilling. Tunas can be bled by cutting the blood vessels that lie under the pectoral fin recess on either side. A vertical cut about 2 cm deep should be made 6 cm (three fingers) back from the pectoral fin. This should be done on both sides of the fish. A drop blood knife is useful for this.
Make a cut all the way around the gill membrane.
Cutting all gill attachments to the head. Then make a cut around the anal opening. (Alternatively, a cut can be made in the belly to within 1 cm of the anus and the intestines cut free of the anus.)