The incidental capture, or by-catch of seabirds in longline fisheries is one of today's most pressing marine conservation issues, calling for international co-operation by all involved.
Longlining is one of the world's major fishing methods, used to catch a variety of fish, from bottom dwelling species like Patagonian toothfish and ling to migratory species like tuna. There are different types of longlines, some designed to lie on or near the seabed, and others designed to float in the water column. All longlines have a mainline and sidelines, with a hook at the end of each sideline. The number of hooks on a line can vary from 800 to 35,000, depending on the type of longline and the fishery.
Albatross and petrel on deck of Japanese
Albatrosses - vulnerable
Albatrosses are renowned ocean wanderers, covering vast distances in a relatively short space of time.
The flight path of a wandering albatross, one of the world's largest flying birds, was tracked for the first time in 1996 using a radio-satellite transmitter. The bird left the Antipodes Islands on 27 January 1996 and arrived in waters to the west of Chile on 13 February 1996. The flight, which covered about 8,000 kilometres, took 17 days."
Albatrosses and petrels are vulnerable to being caught on longlines because of their ability to dive beneath the surface and take baited hooks while longlines are being set. In certain conditions, birds can get hooked or tangled in the line, and drown.
Most albatrosses are long lived (50—60 years), mature late and produce only one chick every 2 or more years. Both parents tend the chick for 4—9 months. Increased death rate of adult birds from fishing has been shown to trigger population declines for several albatross populations in the Southern Ocean over the last 30 years.
It is estimated that tens of thousands of seabirds are killed each year in the Southern Ocean alone. Some fishing fleets have changed their fishing practices to reduce the problem. In New Zealand some vessels only set their lines at night when seabirds are less active and many vessels use bird scaring lines that prevent seabirds from getting to the bait while it is near the surface. New Zealand fishing companies are working with the Department of Conservation to develop additional ways to further reduce the numbers of seabirds caught.
Unless all fleets fishing in vulnerable seabird feeding areas around the world make a similar effort, the threat will remain.
It is in the interests of fishers as well as conservationists to reduce the number of birds caught. Each bait taken equals one less hook fishing - this can be very significant in dollar terms.
New Zealand has a major stake in the issue. Our exclusive economic zone includes some of the world's richest fishing grounds. We are also the custodians of some of the world's richest and most diverse seabird populations.
The Department of Conservation and the Ministry of Fisheries are working with the New Zealand fishing industry to research the problems and find solutions, using funds generated from a levy collected from the fishing industry. Actions to date include:
- Investigating methods of setting longlines that will not catch birds. For example, improving the design of bird scaring lines, adding weights to lines to increase their sink rate, and developing ways of setting lines underwater.
- Placing independent observers on fishing vessels to monitor and report on numbers of seabirds and other marine animals caught.
- Seabird research — Department scientists are involved in an international study using satellite telemetry to track the flight paths of albatrosses — where do they go? what are their important feeding areas?
- Monitoring seabird population trends by visiting islands when birds are on their nests. Because most albatrosses are slow breeders, it will take 10-15 years to build up an accurate picture of what's happening.
- Protecting habitat — New Zealand's subantarctic islands are among the world's most important seabird sanctuaries. We have an international responsibility to care for them.
Global action plan
New Zealand has been pushing for a global approach to reduce the bycatch of seabirds in fishing for several years. Our seabirds are wide-ranging and are caught on other foreign fishing vessels far from New Zealand. So a local approach isn't enough.
The New Zealand fishing industry and conservation groups have also pressed the Government to encourage international fisheries to meet the same standards as our domestic fishing industry to reduce seabird bycatch.
In 1998, 80 countries including NZ supported an international initiative that requires each longlining country to draw up a plan describing how they intend reducing the numbers of seabirds incidentally caught by their fishing vessels. Each country will be required to develop this plan by 2001.
The bigger picture
Loss of seabirds is one of a number of problems affecting the marine environment, including overfishing, marine pollution and global temperature increases.
New Zealand has an important role to play in pressing for the sustainable and equitable management of the oceans and the marine life they support.
Southern Seabird Solutions Trust
The Southern Seabird Solutions Trust was established to promote fishing practices that avoid seabird deaths in Southern hemisphere fisheries. The Department of Conservation is a supporter of the Southern Seabird Solutions Trust.
Fishing and marine and coastal conservation
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