I ran across this public domain feature on tuna fishing posted by www.tunaseiners.com on their Facebook page, and thought it interesting. It shows a style of tuna fishing and canning from a bygone era.
Encontrei este filme de domínio público sobre a pesca de atum na página do Facebook de www.tunaseigners.com, que julguei ser de interesse. Demonstra um estilo de pesca de atum e o elatamento do mesmo em tempos que já la vão.
Tuna are a group of salt water fish from the family Scombridae, particularly of the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of 70 km/h (43 mph). Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red... Some larger tuna species, such as bluefin tuna, display some warm-blooded adaptations, and can raise their body temperatures above water temperatures...
Tuna is an important commercial fish... Tunas are widely but sparsely distributed throughout the oceans of the world, generally in tropical and temperate waters between about 45 degrees north and south of the equator. They are grouped taxonomically in the family Scombridae, which includes about 50 species. The most important of these for commercial and recreational fisheries are yellowfin (Thunnus albacares), bigeye (T. obesus), bluefin (T. thynnus, T. orientalis, and T. macoyii), albacore (T. alalunga), and skipjack (Katsuwonus pelamis).
The report further states:
"Between 1940 and the mid-1960s, the annual world catch of the five principal market species of tunas rose from about 300 thousand tons to about 1 million tons, most of it taken by hook and line. With the development of purse-seine nets, now the predominant gear, catches have risen to more than 4 million tons annually during the last few years. Of these catches, about 68 percent are from the Pacific Ocean, 22 percent from the Indian Ocean, and the remaining 10 percent from the Atlantic Ocean and the Mediterranean Sea. Skipjack makes up about 60 percent of the catch, followed by yellowfin (24 percent), bigeye (10 percent), albacore (5 percent), and bluefin the remainder. Purse-seines take about 62 percent of the world production, longline about 14 percent, pole and line about 11 percent, and a variety of other gears the remainder 3. The Australian government alleged in 2006 that Japan had illegally overfished southern bluefin by taking 12,000 to 20,000 tonnes per year instead of the their agreed 6,000 tonnes; the value of such overfishing would be as much as USD $2 billion. Such overfishing has severely damaged bluefin stocks. According to the WWF, "Japan's huge appetite for tuna will take the most sought-after stocks to the brink of commercial extinction unless fisheries agree on more rigid quotas".
Japan's Fisheries Research Agency counters that Australian and New Zealand tuna fishing companies under-report their total catches of southern bluefin tuna and ignore internationally mandated total allowable catch totals.
In 2010, a bluefin tuna weighing 232 kilograms (511.47 pounds) was sold at Tokyo's Tsukiji fish market for 16.28 million yen ($US 175,000).
In early 2011, a new record was set at 32.49 million yen (nearly $400,000) for a bluefin tuna weighing 342 kilograms (754 pounds), during an auction in Tsukiji Market, Tokyo. This equates to 95,000 yen per kilogram.
In November 2011, another record was set when a fisherman in Massachusetts caught an 881-pound tuna. It was captured inadvertently using a dragnet...
Canned tuna was first produced in 1903, quickly becoming popular. Tuna is canned in edible oils, in brine, in water, and in various sauces. In the United States, 52% of canned tuna is used for sandwiches; 22% for salads; and 15% for casseroles and dried, packaged meal mixes.
In the United States, only Albacore can legally be sold in canned form as "white meat tuna"; in other countries, yellowfin is also acceptable. While in the early 1980s canned tuna in Australia was most likely Southern bluefin, as of 2003 it was usually yellowfin, skipjack, or tongol (labelled "northern bluefin").
As tunas are often caught far from where they are processed, poor interim conservation can lead to spoilage. Tuna is typically gutted by hand, and later pre-cooked for prescribed times of perhaps 45 minutes to three hours. The fish are then cleaned and filleted, canned, and sealed, with the dark lateral blood meat often separately canned for pet food. The sealed can itself is then heated (called retort cooking) for 2 to 4 hours. This process kills any bacteria, but retains the histamine that can produce rancid flavors. The international standard sets the maximum histamine level at 200 milligrams per kilogram...