Plastic in the Depths: as ghost gear chokes the ocean – campaigners call for mesures
A trip to the remote north Pacific gyre provides a stark reality check on the scale of the planet’s plastic waste crisis. “You’ve been sailing at 10 knots for five days, you’re alone. You don’t see any other boats. And then you find toothbrushes and lighters floating around you,” says Laurent Lebreton, head of research at the Ocean Cleanup, a Dutch non-profit organisation that develops technology to extract marine plastics. “It’s just very surreal.”
What he finds most striking, however, are the metres of netting, ropes and line, luminous orange buoys, crab pots and fish traps: remnants of the global fishing industry, drifting around in what is known as the “great Pacific garbage patch”.
From samples gathered by the Ocean Cleanup’s floating boom system – which rakes in plastic from this swirling gyre – Lebreton’s new research deciphered clues on some of the plastic fragments, which suggest that most of that waste can be traced back to five industrialised fishing nations: the US, Japan, South Korea, China and Taiwan.
Typically, the finger of blame for marine plastic is pointed at terrestrial pollution from rapidly developing economies in south-east Asia and elsewhere, Lebreton says. But his fresh discoveries highlight the contribution of industrialised nations to this problem, too.
An October survey of 450 fishers from seven big fishing nations estimated that 2% of fishing gear used globally ends up in the ocean. The share may seem small but the scale of global fishing is enormous, says Kelsey Richardson, the lead author on the study.
It amounts to an estimated 3,000 sq km of gill nets, 740,000 km of longline mainlines, and 25m pots and traps. At the current rates of loss, the amount of stray fishing nets measured by area would be enough to carpet the surface of the planet in 65 years, the researchers found.
Ghost gear contributes about 20% of marine plastic – with most of the rest coming from land-based sources – but underwater, its effects are profoundly worse. “It continues to operate as something that catches marine wildlife,” says Christina Dixon, ocean campaign leader at the Environmental Investigation Agency. “It’s an invisible killer.”
The World Wide Fund for Nature calls fishing waste the deadliest form of marine plastic, finding that entanglement or entrapment by ghost gear affects 66% of marine animals, including all sea turtle species and 50% of seabirds.
Different types of ghost gear can form giant masses – such as the 9,000kg ball of jumbled rope, nets and line that the Ocean Conservancy helped fishers haul up from the seafloor off the coast of Maine in 2019. It was “floating beneath the surface, out of sight”, Giskes says. These layers of waste can pose navigational hazards and crush ecosystems such as coral reefs and seagrass meadows, creating barriers and stifling marine life.
There are many reasons fishing gear ends up as marine waste – from stormy weather to poor storage and gear snagging on the seafloor. Fishers facing tough economic conditions may take more risks to catch fish, says Richardson, increasing the likelihood of damaging or losing gear. The especially risky conditions around illegal fishing mean that this shadowy phenomenon is probably contributing even more to the waste.
source : The Guardian