BIRD SCARING LINESLong line fishing is a widely used fishing technique and is practiced in every major ocean of the world. More than one million hooks are set each day, with up to 200 million hooks per year set in the Southern Ocean alone. It has been estimated in recent years that 300 000 seabirds are killed each year globally.
Birds are killed primarily when they swallow baited hooks during the setting of longlines. The birds get entangled or hooked and drown as they are dragged underwater. Birds are also fatally injured on occasion during hauling operations as they snatch baits being hauled to the surface.
The pelagic longline fishery, targeting Tuna and Swordfish, kills a significant number of birds each year. This is the largest longline fishery in the Southern Ocean and is responsible for the deaths of tens of thousands of albatrosses and petrels each year. It was estimated, in a study conducted in South Africa, that between 19 000 and 30 000 albatrosses and petrels are killed each year by this fishery.
The demersal longline fishery targeting Hake in the continental shelf waters around southern Africa, also affects seabird populations. It was previously estimated that the South African hake longline fishery kills approximately 8 000 White-chinned Petrels, Procellaria aequinoctalis, (0.4 birds per 1000 hooks set) annually. More recent studies have shown a decrease in bycatch rates because of an improvement in mitigation measures. Fortunately for the albatrosses, this fishery sets lines mostly at night, so few albatrosses, which feed during the day, are caught. However species such as the White-chinned Petrel which may also feed during the night are killed.
A tori or bird scaring line consists of a line with a number of streamers attached to it. This line is towed from the stern of the vessel while the baited lines are being set. The streamers are designed to cover the point where the bait enters the water and distracts foraging birds from taking the baited hooks. The system works well against surface feeding birds, however diving birds can still dive down to the bait outside of the effective area of the streamers. Still, this method may reduce bycatch rates by up to 80%.
KEAG, under the WftC project has been asked by WWF-SA and Birdlife SA to make 500 tori lines over the next two years. KEAG is doing this in partnership with the Ocean View Association for Persons with Disabilities.
