Through David Hambling

Hundreds of thousands of tons of lost, abandoned and discarded fishing gear litter the world’s oceans. In some areas, this gear accounts for 30 percent of the catch, trapping turtles, seabirds and whales as well as commercially caught species.

Kelsey Richardson of CSIRO, Australia’s national scientific research agency, and her colleagues combined 68 studies from 32 countries and territories to assess the scale of the problem.

The team found that 6 percent of nets, 9 percent of pots and 29 percent of lines are lost in the ocean each year due to commercial fishing. While line losses are the highest in percentage terms, it was often just one section of line, whereas when a trawl was lost it often meant the entire trawl gear. .

The researchers found that the most common causes of loss were inclement weather, gear getting stuck on the seabed, and “gear conflicts”, where pieces of equipment get tangled up with each other. The types of nets that drag along the seabed are the most likely to be lost.

Previous studies have shown that “ghost fishing” by abandoned gear can capture large quantities of fish. This includes up to 5 percent of the catch in the Baltic Sea and up to 30 percent of Norway’s Greenland halibut. Studies tend to focus on the waters around Europe and the United States, and little is known about regions in Africa, Asia, South America, and Oceania.

Abandoned equipment makes up a large portion of the plastic waste in the world’s oceans, including 46% of the plastic in the Great Pacific Garbage Patch.

“When plastic fishing gear pollutes our global ocean, it can persist for hundreds of years. We haven’t been using synthetics long enough to see plastic fishing gear disappear or completely decompose, ”says Richardson.

When they finally break down, plastic gears can enter the food chain as microplastic particles.

The next step in the research is to ask fishermen around the world how much gear they lose and why, and to suggest possible preventive measures. This will fuel a more accurate estimate of global losses and inform plans to mitigate the problem.

“The human activity with the greatest impact on the health of our oceans is fishing, and this study highlights an often-overlooked part of the problem,” says Helen McLachlan, fisheries program manager at the conservation organization WWF -UK, stressing the need for action. . “We must do everything possible to minimize the loss or abandonment of gear across our oceans, for the good of our marine life around the world.”