When a fish struggles against the angler its body temperature increases dramatically. Upon landing, its body temperature should be lowered immediately to prevent the meat ‘cooking’ from the inside out. The fish needs to be bled first, by sticking it with a knife just behind the pectoral fin, before (ideally) being immersed in an ice slurry, or at the very least, placed in an insulated body bag along with loose or blocked ice.
With more and more anglers landing bluefin tuna off the South Island’s West Coast, people are developing a taste for this species as well. One of these giants will feed many mouths. 
Much more common in our waters are skipjack (often incorrectly referred to as ‘bonito’) and albacore tunas; the latter earning the title ‘chicken of the sea’ because of its succulent flesh.
Tuna can be smoked, with albacore coming up especially well prepared this way. Many anglers have their yellowfin and albacore canned professionally, resulting in a great product for summer salads and winter fish pies. Yellowfin and big-eye in particular are prized as sashimi, or else cooked as steaks.
Regardless of how you like it, tuna of every species generally need special attention when cooking to prevent the meat drying out as a result of being left on the hotplate for too long. Depending on their thickness, tuna steaks only need a minute or two per side on a smoking-hot hot plate, grill or pan. Rice bran oil is great for cooking tuna steaks – indeed, most fish species – because of its high flash point.
While the bigger tuna species freeze well, especially if snap-frozen as individual steaks and then vacuum packed, albacore is best eaten fresh, as it tends to come out of the freezer ‘mushy’.
While skipjack tuna is acceptable as a table fish, many will agree its best use is as bait for other species, deployed alive or dead! All tuna is enhanced by a good marinade, even something as simple as a little virgin olive oil mixed with Kikkoman’s soy sauce, and seasoned with ground pepper and sea salt.