hammerhead caught on a longline
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hammerhead caught on longline shark finning


Longlining

One of the priority campaigns for marine conservation organisations is the global problem of longline fishing.


What is a Longline?


A longline is a fishing line usually made of monofilament. The length of the line generally ranges from 1.6km (1 mile) to as long as 100km (62 miles). The line is buoyed by styrofoam or plastic floats. Every hundred or so feet, there is a secondary line attached extending down about 5m (16 feet). This secondary line is hooked and baited with squid, fish, or more disturbingly, with fresh dolphin meat. The baited hooks can be seen by albatross from the air and when they dive on the hooks, they are caught and they drown. Other forms of marine wildlife see the bait from the waters below and get hooked when they try to eat the bait. The lines are set adrift from vessels for a period of 12 to 24 hours.


Twelve of the world's 14 albatross species are believed to be dying in the tens of thousands each year in this way. Because of the large number of birds affected, commercial fishing has been identified as the most serious threat to the survival of most albatross species.

Many species of sea turtles fall victim to the deadly hooks of the longliners. 20,000 loggerhead turtles are captured every year by the Spanish longline fishery in the Mediterranean Sea, and 4,000 of them are believed to die because they are returned to the sea with the hook still embedded in their throats. Sea Shepherd crew have recorded dozens of turtle carcasses along the Pacific coast of Central America. When examined, all the dead turtles were found to have hooks embedded in their throats.

According to the National Marine Fisheries Service (NMFS), 75% of the loggerhead turtles and 40% of the leatherback turtles taken by United States-based pelagic longliners in the Atlantic are caught on the Grand Banks in the North Atlantic . The United Nations Food and Agriculture Organization (FAO) reports that 40,000 sea turtles are killed annually in the global longline fisheries.



Leatherback turtles, the largest turtles in the world, will be extinct within a few decades if current fishing practices continue. That is the conclusion of marine researchers speaking at the 2002 annual meeting of the American Association for the Advancement of Science in Denver. "We've done specific analysis on beaches where we've got a lot of data and we expect them to disappear in 10 to 30 years," said Larry Crowder, from Duke University, North Carolina.




What Are These Longlines Doing to the Sharks?


Longlines are the most significant factor in the rapid diminishment of shark populations in the oceans. Longlines ranging from one mile in length to over one hundred miles in length are baited with fish, (often illegally killed dolphins or seals), and are meant to target shark, swordfish, and tuna. The sharks targeted are caught mostly for their fins (which account for only 4% of their body weight) and also for their cartilage, liver oil, and teeth. The longline fishermen remove the fins and toss the still living shark back into the sea to die an agonizing death. Unable to swim, they slowly sink towards the bottom where other fish eat them alive. If longlines are not abolished, the oceans will lose most species of sharks within the next decade.

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