|Problems with Fishing Fleets|
Photo by Graham Robertson ©: A Wandering
Albatross hooked on a fishing line and drowned
in a longline tuna fishery off eastern Australia
after flying some 9000km from its home on
South Georgia Island. Used with kind permission.
|Scientists have realized in
the past few years that albatrosses all over the world are being caught accidentally by
fishing fleets. Longline fishing for tuna and "billfish" (like swordfish) is a big
concern. We know that both Laysan and black-footed albatrosses in the Hawaiian
islands are being caught on longline hooks. We hope that our satellite tracking
data will show the favorite hunting areas of the birds so that we can give special
attention to human fishing activity in those areas.
Longlining gets its name from the length of the lines that are used. Some longliner boats set lines of over 100 km with more than 20,000 hooks attached. There are many species of fish that are targeted by longline fisheries that operate all over the world. In the waters surrounding Antarctica alone, the various tuna fleets set over 200,000,000 hooks annually. There are similar sized fleets in all the other oceans. These operate alongside other kinds of fishing boats to catch some of the most expensive fish in the world. A large adult tuna can reach a weight in excess of 700kg and swim at 90km per hour. The Japanese Sashimi and Sushi markets sell the best quality tuna meat, and a single fish can sell for more than US$60,000 (USA dollars) !
|There is evidence to
suggest that several populations of albatrosses are decreasing as a direct result of
longlining. Baited hooks attract
seabirds. Seabirds have learned to scavenge food from
ships. When a longline is put into the water, thousands of baited hooks are let out behind
a moving boat. Seabirds that are following the boat attempt to steal the bait and
often get hooked. The sinking longline draws them under water and they drown.
Unless properly managed, every single hook that is set (estimated to be between 1
and 10 billion globally each year) has the potential to catch birds.
This accidental catch of birds is called "bycatch". In 1991 it was estimated that the Japanese Tuna longliners off Australia killed 250,000 birds annually. This figure may have decreased as new measures have been put in place to reduce bycatch. There are solutions to the bird bycatch problem, which are neither overly restrictive nor very expensive to the fishery - especially in the light of the economic value of the fish and the aesthetic value of the birds that are being caught.
This information came from the very useful web site of Birdlife International Global Seabird Conservation
This page was last updated on April 20, 1998 02:58 PM