Report by Shark Info
Blue sharks are often caught as bycatch by longline fisheries.
During the catch period between 1993 and 1995 it is estimated that
between 50 and 120,000 individuals were caught annually alone in the
North Atlantic catch area. Blue shark meat is not deemed
commercially interesting, especially since legal catch regulations
limit the quotas in the U.S. According to the authors, about 81% of
the animals caught on hooks are released alive.
Those blue sharks living in the open sea are often caught by sports
fishermen off the U.S. coast between Maine and New Jersey, but
precise catch statistics from sports fishery are not available.
The jaw of a blacktip shark (Carcharhinus limbatus)
with ingrown fishing hook. The colored and structurally changed
region around the hook marks the intense area of inflammation.
© Gaston D. Guex / Shark Foundation
example, during a two-day competitive fishing event in Massachusetts
over 2,000 blue sharks were caught, 99% of which were apparently
released alive. Unknown is how many of these animals die later on as
a consequence of the traumatic catch. In any case many of these
sharks have problems with fishing hooks stuck in their jaw, their
gullet or intestinal tract. The hooks begin to rust and trigger
antibody reactions in their bodies.
The authors describe growths (fibroms) in the connective tissue,
stomach inflammation (gastritis), inflammation of abdominal cavities
(peritonitis), perforated liver resulting in inflammation
(hepatitis) and tissue growth, inflammation of the esophagus
(esophagitis) and as a mechanical result strong obstructions of the
esophagal area. Transported by the fishing hook, bacteria and fungi
directly enter the punctured tissue and trigger various
inflammations. The 211 animals examined were caught by anglers
within four days (July 1999, 81 specimen; June/July 2000, 130
specimen) in Montauk, New York. All blue sharks caught were males.
Six of them had old remains of fishing hooks in their bodies and
formed the basis of this research. The weight of the respective
sharks was in a normal statistical range so they were considered
Source: Journal of Fish Diseases 25 (9), pp 515-521.
Borucinska J., Kohler N., Natanson Skomal, G. (2002). Pathology associated with retained
fishing hooks in blue sharks, Prionace glauca (L.), with
implications for their conservation.
last change: 12-06-2009 12:52 /