Ken Schultz's Field Guide to Saltwater Fish - Macaw Pets store

Tuna, Bluefin
Thunnus thynnus
OTHER NAMES
Atlantic bluefin tuna,
northern bluefin tuna,
tunny fish, horse-mackerel;
Arabic: tunna; Chinese: cá
chan, thu; French: thon
rouge; Italian: tonno;
Japanese: kuromaguro;
Norwegian: sjorjf, thunfisk;
Portuguese: atum, rabilha;
Spanish: atún aleta azul,
atun rojo; Turkish: orkinos.
Distribution/Habitat.
Bluefin tuna occur in subtropical
and temperate
waters of the north Pacific
Ocean and the North
Atlantic Ocean and in the
Mediterranean and the
Black Seas. They are widely
distributed throughout the
Atlantic. Distribution in the
western Atlantic occurs
along Labrador and Newfoundland
southward to
Tobago, Trinidad,
Venezuela, and the Brazilian
coast; they are especially
encountered by anglers off
Nova Scotia and Prince
Edward Island; Cape Cod;
Montauk, New York; the
canyons offshore of New
York and New Jersey; the
North Carolina region; and
254 Tuna, Bluefin
The bluefin tuna is the largest member of the Scombridae
family and one of the largest true bony fish. A pelagic,
schooling, highly migratory species, it has enormous commercial
value, especially in large sizes, and is of significant
recreational interest.
High demand for its dark red flesh has made the bluefin
tuna the object of intense commercial and recreational fishing
efforts and has resulted in a dwindling population of
adult fish. This species, as well as its cousin the southern
bluefin tuna, is gravely overfished. According to some estimates,
the population of the species in the western Atlantic
has declined by roughly 87 percent since 1970.
Because bluefin tuna are slow to mature, they are especially
vulnerable to overexploitation. Although some catch
quotas have been established, the continued landing of
small bluefins, as well as large ones (called giants), in some
regions; the failure to restrict harvest in others; the ignorance
of restrictions by commercial fishermen of some
countries; the lack of punishment or enforcement; and the
managerial treatment of bluefins on a separate two-stock
basis, instead of on one interpolar migratory one, are leading
reasons for both species of bluefin tuna to be further
troubled, if not endangered. In 1996, scientists warned that
existing worldwide catch quotas would have to be cut by
80 percent for populations to recover in 20 years, but these
were raised instead.
Identification. The bluefin tuna has a fusiform body, compressed
and stocky in front. It can be distinguished from
almost all other tuna by its rather short pectoral fins, which
extend only as far back as the eleventh or twelfth spine in
the first dorsal fin. There are 12 to 14 spines in the first dorsal
fin and 13 to 15 rays in the second. The anal fin has 11
to 15 rays. The bluefin has the highest gill raker count of
any species of Thunnus, with 34 to 43 on the first arch. The