“Ghost” fishing gear includes the lost, abandoned or discarded fishing nets, lines and hooks that pollute the world’s oceans and entangle marine mammals, sea turtles, sharks and seabirds, leading to slow and painful deaths from suffocation and exhaustion. Marine habitats like coral reefs are also damaged by ghost gear.
Not only does the ghost fishing gear account for about 46 percent of the Great Pacific Garbage Patch, according to the World Wildlife Fund (WWF), a new study has found that the amount of commercial fishing line left in Earth’s oceans each year is enough to stretch to the moon and back, reported The Guardian.
According to the study, the amount of gear lost annually includes more than 25 million traps and pots and almost 14 billion longline hooks.
“These figures are breathtaking. This gives us a sense of the horrendous scale of the problem and the urgent need to tackle it,” said Head of Oceans and Sustainable Development at WWF Australia Richard Leck, as The Guardian reported. “Ghost nets — as they’re known — are a particularly lethal form of plastic pollution for all the marine life we care about. Once these nets are lost from a fishing vessel, they don’t stop fishing.”
Each year, the number of lost nets is enough to cover Scotland, and if all the lost fishing line was tied together it would be enough to circle the equator 400 times, reported Science.
“This is having an unimaginable toll of unknown deaths that could result in population level effects for marine wildlife,” said one of the study’s authors Dr. Denise Hardesty of the Australian government’s CSIRO science agency, as The Guardian reported.
The study, “Global estimates of fishing gear lost to the ocean each year,” was published in the journal Science Advances.
To determine what gear was being lost in the ocean, researchers from the University of Tasmania and CSIRO interviewed 451 commercial fishers from Morocco, Belize, Peru, Indonesia, New Zealand, Iceland and the United States, reported The Guardian. The researchers chose those countries because their fishing industries used most commercial fishing techniques.
The researchers then matched the information from the interviews with global commercial fishing data.
Lead author of the study Kelsey Richardson said the surveys found that an average of about two percent of the gear from fishing vessels was lost in the world’s oceans each year, Science reported.
The research team estimated that 46,000 miles of main long lines, 9.6 million miles of branch lines, 30,000 square miles of gillnets and purse seine nets and 83 square miles of bottom trawl nets — in addition to the traps, pots and longline hooks — were lost annually, reported The Guardian.
The study found that more gear was lost by smaller boats than larger ones and that more nets were lost by bottom-trawl fishers than by midwater trawlers.
Nets were often lost when they floated away or weren’t property connected during bad weather, or when gear from competing vessels became entangled, Hardesty said. Since the gear was designed to entrap and kill marine life, it will keep doing so as it floats through the ocean, sinks to the bottom or makes its way ashore, Hardesty added.
“You are then also catching a whole bunch of fish but then not eating them. That becomes a food security problem because that’s protein that’s not feeding people around the world,” said Hardesty, as The Guardian reported.
Older fishing equipment tends to get lost more frequently, so local governments buying it back is one possible solution, Hardesty said.
Another strategy is to keep boats out of areas with lobster traps, lessening the odds that the lines attached to traps that allow them to be retrieved will be severed by a propeller, reported Science.
“I tell people over and over again that fisheries management is key,” said Richardson, as Science reported.
Other solutions include attaching labels or tags to fishing gear, and providing places at harbors where fishers could dispose of nets that have become unusable free of charge, reported The Guardian.
“This affects all countries – not just the places where nets are lost. This gear can migrate around oceans and continue to catch fish and entangle threatened species,” Leck said, as The Guardian reported.