According to the most comprehensive survey of lost fishing gear ever, there is enough commercial fishing line left in the ocean each year to stretch to the moon and back.
The staggering amounts of lost gear, which includes 25 million pots and traps and 14 billion hooks, likely have deadly consequences for marine life, one of the study’s authors said.
Enough nets have been lost or cast each year to cover Scotland. If all types of lost lines were tied together, they could circle the Earth 18 times.
“It’s super confronting,” said Dr Denise Hardesty, of the Australian government’s science agency CSIRO, and one of the study’s authors.
“This has an unimaginable number of unknown deaths that could have population effects for marine wildlife.”
Published in the journal Scientists progressresearchers from CSIRO and the University of Tasmania used standardized interviews with 451 commercial fishermen in seven countries to ask what was lost.
The researchers compared these interviews with data on the amount of commercial fishing around the world to estimate what was lost. Annual losses included:
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78,000 km² (30,000 sq mi) of purse seines and gillnets
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215 km² of bottom trawls
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740,000 km (46,000 miles) of long main lines
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15.5 million km (9.6 million miles) of branch lines
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13 billion longline hooks
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25 million traps and traps
Fishermen from the United States, Morocco, Indonesia, Belize, Peru, Iceland and New Zealand were interviewed. Countries were chosen because they had a fishing industry using most fishing methods.
Small boats lost more gear than large boats, and bottom trawlers lost more nets than pelagic trawlers.
A previous estimate placed the percentage of lost gear at a higher level, but this research was based on a series of studies, rather than a standardized estimate based on interviews.
Hardesty said anglers often lose nets due to bad weather where gear isn’t properly secured or buoyant, or gear gets tangled with gear from other vessels competing for the same fish. .
But she said that because the nets were designed to catch and kill animals, the lost gear would continue to trap wildlife for years as they floated in the ocean, sank to the bottom or washed up on shore.
“It’s birds, turtles, whales, sharks, dolphins, dugongs,” she said.
“You then also catch a whole bunch of fish but you don’t eat them. It becomes a food safety issue because it’s protein that doesn’t feed people in the world. »
Kelsey Richardson, lead author from the University of Tasmania, said the detailed estimates should help fisheries managers, the commercial fishing industry and conservationists better target solutions.
The nets were aggravating the global problem of marine plastic pollution, she said
Hardesty said there are solutions, such as local governments introducing buybacks for older fishing gear that tended to get lost more often than new gear. Tags or tags could be attached to gear and free facilities could be set up in ports to enable fishermen to safely dispose of unusable nets.
Richard Leck, Oceans Manager at WWF Australia, said: “These numbers are breathtaking. This gives us an idea of the appalling scale of the problem and the urgent need to tackle it.
“Ghost nets – as they are called – are a particularly deadly form of plastic pollution for all the marine life we care about. Once these nets are lost from a fishing vessel, they do not stop fishing.
Leck said a global plastic pollution treaty currently being negotiated through the United Nations should address ghost nets “at a global level to ensure countries are accountable” through reporting and transparent labeling of fishing gear.
“It affects all countries – not just the places where nets are lost. This gear can migrate around the oceans and continue to catch fish and entangle endangered species.
