A little more than a decade ago, thousands of seabirds including the magnificent wandering albatross, with the longest wingspan of any bird in the world perished annually in the Southern Ocean surrounding Antarctica when they dove for baited hooks set by longline fishing boats. Impaled on the hooks, the birds were dragged underwater and drowned.
But in recent years, increased regulations, stricter enforcement, and innovative gear including the adoption of technologies that weigh down baited hooks well below the surface or scare seabirds away from longlines have had a dramatic impact on so-called seabird bycatch. The number of drowned seabirds in the Southern Ocean surrounding Antarctica has fallen to near zero in the legal fishery, experts say. Another key factor was a requirement by the Commission on the Conservation of Antarctic Marine Living Resources that a scientific observer be placed on every fishing boat operating in the Southern Ocean.
“Where environmental organizations, fishery managers, and fishermen work together great results have been achieved,” says Ramunas Zydelis, a seabird expert with the Center for Marine Conservation at Duke University. “Seabird bycatch has been reduced by 90 percent and more in longline fisheries in the Southern Ocean, Hawaii, Alaska, South Africa, and New Zealand.”
Such efforts are sorely needed, as the number of seabirds drowned by longline fisheries estimated at 160,000 to 320,000 annually remains hugely unsustainable. This toll is emblematic of a wide array of threats facing seabirds today. Having navigated the perils of marine life for 65 million years, seabirds face unprecedented challenges, particularly from industrial fisheries.
Two recent studies have highlighted the intensifying pressure on the world’s seabirds. A recent paper in Bird Conservation International noted that 28 percent of the world’s 346 seabird species are listed as threatened by the International Union for Conservation of Nature’s Red List more than double the percentage of birds imperiled as a whole (12 percent). The study concluded that nearly half 47 percent of the world’s seabirds are in decline.
And a recent study in Science drew attention to another, less publicized danger facing seabirds: the decimation by fishing fleets of the small fish and other prey species that seabirds depend on. The study, published last December, concluded that whenever prey populations fall below one third of their maximum abundance, seabird breeding suffers and populations fall.
Scientists say the decline in seabird populations is a warning sign of a broader assault on the world’s oceans, from overfishing, to pollution, to climate change.
2012 Guardian News and Media Limited