The bluefin tuna is one of the largest of the tunas found in both the Atlantic and the Pacific but becoming increasingly uncommon. The Northern bluefin is Thunnus thynnus, also known as the longtail tuna. It is an unusually elongated and elegant tuna and has very dark, rich, buttery flesh, as we found after we caught this one in northern Queensland and ate it as sashimi shortly after. What does not show very well in this picture is that the hard lumps on the tail, in Christian's right hand, were bright yellow. These fish are caught everywhere except for around the southern coast of Australia.
The Southern bluefin is Thunnus maccoyii and the Pacific bluefin is Thunnus orientalis. The flesh of these is paler pink and has a stronger flavour than the albacore tuna. The younger the fish, the lighter and milder the flesh, gaining both colour and flavour as it ages. I once saw a bluefin tuna the size of a large cow, short but immensely fat, landed on the quay in Alonissos. It was cut into colossal, red steaks. They are now hardly found in the Mediterranean at all.
To quote an article in The Observer on 14th February 2010, ""Stocks of bluefin tuna in the western Atlantic have dropped by 82% since 1978, while those in the eastern Atlantic have dipped by 80%," said Heather Sohl of the WWF. "We are looking at a species that is going to be fished into extinction unless we take urgent measures to save it."" .
But with a giant bluefin tuna fetching £110,000 (16.3 m yen) at auction in Tokyo in late 2009, how is this trade to be reduced? And reducing fishing of this species will probably mean an increase in fishing of other species which are presently at risk, but not so desirable. Just as we have leaned how important it is to eat fish, we find the seas cannot support our appetites. It is estimated that about a million bluefin tuna were fished in 2009, of a probably population of around 3.8 million. "That greatly exceeds the power of the species to replace its numbers" said Sohl
Finally, just to make you feel even better, the collapse of bluefin numbers in the Mediterranean will lead to a rise in squid numbers, the consequence of which is an adverse effect on the sardine population. And so it goes on.