Operations vary from small boats that fish close to the coast to vessels that fish on the high seas. Vessels that fish on the high seas might have freezers of 200-300 tonnes capacity and can stay at sea for several months. Pelagic longliners might deploy longlines up to 130 km long with 3,000 hook-bearing branch lines. Branch lines are usually 30-40 metres in length and 50 metres apart on the longline, and are light enough to bob up and down in the water column in order to attract fish. Longlines are set and hauled back in on every day of the fishing operation.
Species targeted include hake, ling, cod, sablefish, halibut and Patagonian toothfish.
The main species of seabirds killed in longline fisheries are albatrosses and other species of petrel. Black Browed Albatross killed by a longline fishing hook Seabirds get caught when baited hooks are payed out from vessels during line setting operations. When longlines are deployed they flounder near the surface which provides visual cues for seabirds. Seabirds take baits by surface-seizure or by diving for them. They bite the baits, become hooked and when longlines sink to target depths the birds get pulled underwater and drown.