Tuna Species "Tuna" is the general name applied to the Teleostei, Percida, Scombina, and Scombridae species of fish. Mainly inhabiting the open sea, these fish are extremely agile and can cover long distances at high speeds. They also reside at the top of the food chain among other fish species. There are several types of tuna: bluefin tuna, southern bluefin tuna, bigeye tuna, yellowfin tuna, albacore, etc. Approximately 1.6 million tons of tuna are caught worldwide each year. What is Longline Fishing? Longline fishermen are succeeding in their efforts to feed the world through sustainable and environmentally-friendly harvests. Hundreds of different types of fish and shellfish are harvested each year to produce food for the people of the world. To catch this diverse and renewable harvest, fishermen use a wide variety of different fishing gear and methods. One of these methods, called longline fishing, is an effective and environmentally friendly way to harvest seafood. It is used in oceans all over the world in small-scale fishing as well as in modern mechanized operations. Tuna longline fishing was predominantly developed in Japan. Longline gear is based upon a design consisting of three parts: the mainline, gangions (individual "branch" lines attached to the mainline), and baited hooks. Longline vessels set out a mainline supported by floats that may extend for miles beneath the surface of the ocean. Hanging at regular intervals from the mainline are the gangions with baited hooks which can be adjusted to fish at varying depths. As a passive (stationary) type of gear, a longline's chance of success is based on the target species' demand for food. Fish are caught on longlines because they are attracted to their baited hooks. (Source: Abstracted from International Coalition of Fisheries Association pamphlet.) Tuna Types Bluefin Tuna Found in subtropical and temperate waters of the Atlantic and north Pacific Oceans, also in the Mediterranean and Black Seas. Its high-quality meat commands a premium price in the "sashimi" market in Japan. Southern Bluefin Tuna Known to migrate across the southern oceans and is mainly caught in cold waters off South Africa, Australia and New Zealand. The fatty meat of this type is particularly favored in posh Japanese restaurants and "sushi" shops. Bigeye Tuna Distributed widely in all waters of three major oceans. Frequently confused with the Yellowfin, but differs with a heavier and thickerset body. The name originates from its appearance. Yellowfin Tuna Distribution similar to the Bigeye, but is characterized by a slim body and a belly crossed by vertical lines of light spots. Comprises the largest global catch in commercial tuna fisheries. Albacore Highly migratory species found in temperate and tropical waters. Characterized by its long sword-shaped pectoral fins. Its white meat is typically used for canned tuna. Skipjack Found in tropical and subtropical waters of all oceans and seas. Available all year round in southern waters but seasonally in colder waters. Its meat is widely used, eaten raw as "sashimi," canned, or dried to produce fish broth for Japanese cooking. Tuna Sizes Bluefin So. Bluefin Bigeye Yellowfin Albacore Skipjack Tsukiji - the Japanese wholesaling tuna market (Reported by Nualanong Tongdee, 4 November 2004) Being one of the largest wholesale markets of Japan, Tsukiji market started its operation in 1935. Although the market is widely known as a 'fish' market, it is also an important market channel for fruits and vegetables as well. Tuna is among various categories of marine products being traded here. Most of tuna, both fresh and frozen, came from longline operations all over the world. Frozen tunas were landed at the Shimizu, Yaizu, or Misaki ports, while some of the fresh ones also came through the Narita airport, and being transported to Tsukiji. Fish were loaded to the market at night, checked for hygienic standard, and be ready for auction very early in the morning (before 5 a.m.). The selling process started from wholesaling where the whole body tunas were sold by auction. Each tuna was then be sliced (or electric sawn, in the case of frozen tuna) into smaller pieces and sold to retailers or other supermarket agents at the intermediate wholesaling shop, also located in the market area. As 'freshness' is the most important factor for all the marine products in Japan, the whole selling process usually finished by 10 a.m., allowing time for wholesalers to conclude their sales and prepare for tomorrow's auction. After the World War II, Tsukiji used to have as many as 1,600 intermediate wholesaling shops. However, at present, the number of these shops reduced to only about 830, due to the declination of marine production, the competition among shops, and the introduction of credit payment system by most of the supermarket chain. Fresh tuna (left) and its quality examination (right) Frozen tuna (left), the auction (middle), and slicing of tuna before intermediate wholesaling (right) Tuna intermediate wholesale shop (left), and fresh tuna meat ready for retailers (right) For more detail about Global Tuna Supply and Sashimi Tuna, click here. Copyright (C) 2004 OPRT. All Rights Reserved.