Bluefin tuna are caught each year in Sicily in the 'Mattanza'. Tuna biology, fishing and problems for sharks and dolphins are mentioned.
In Sicily they catch tuna(1) in a traditional festival known as the mattanza (images) which takes place in May and June each year. A huge trap (called the tonnara) leads the fish into a chamber, called la camera della morte, which has a net floor that can be raised. The fish are then brought to the surface and killed. During this festival, while the tuna(2) are being caught, Tonnarotti sing special songs called scialome which have been passed down for so long that much of the meaning has now been lost. The term 'mattanza' comes from the old Spanish word, matar, while other words, such as rais (the head fisherman of the mattanza), are of Arabic origin. There are only a few genuine mattanzas left now, and these are all to be found to the west of Sicily, among the Egadi Islands.
Tuna Biology:
The Northern Bluefin (or Atlantic Bluefin) tuna, Thunnus thynnus (Linnaeus, 1758), is one of the most highly evolved of all fish. It is one of the very few that are truly warm-blooded. They can keep their body temperature several degrees higher than the surrounding water (unusual haemoglobin is probably involved in this trick). Being warm allows them to swim at up to 45 miles per hour and travel enormous distances. (One was tracked via satellite from Sardinia to Spain, down past the Equator and then up to Greenland.).
Tuna are very long-lived with an average lifespan of 15-30 years. They are active hunters eating mackerel, herring, whiting, flying fish, and mullet as well as squid, eels, and crustaceans.
Spawning takes place in the Mediterranean from June to August, mostly around Sicily. Unfortunately tuna have a very slow breeding rate (taking at least 10 years to become sexually mature), so they are vulnerable to overfishing.
Fishing for Bluefin Tuna:
International sport fishing for Bluefin started about 100 years ago, but before 1970 it was only for fun since the fish were only worth about $.05 per pound. This all changed when the Japanese market opened in the 70’s. Tuna were suddenly worth big money and any large trophy fish caught now is a highly valued Japanese delicacy. A lot of sport fishermen have now got commercial permits and sell their catch commercially. (The highest amount paid for a Bluefin was $180,000 on the Japanese fish market!)
Problems for Sharks and Dolphins:
All the Tuna you buy comes from wild fish, some caught using vast purse-seine nets to scoop them out of the sea, and some from lines of baited hooks many miles long. Unfortunately these methods catch many other creatures at the same time, including sharks. Longlines around New Zealand are said to have caught 450,000 blue sharks in 10 years!
And there are serious problems for Dolphins. Follow these two links to start researching them. Dolphins may be caught at the same time, or Dolphin mothers may be separated from their young.
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