"No part of the planet is free of plastic waste, and coral reefs are no
exception, but scientists have now made the discovery that the deeper the reef,
the more plastic debris it is likely to have.
A study published in Nature
found that not only is every coral reef
encumbered with plastic, but almost three-quarters of the larger items were
from “ghost gear” – fishing paraphernalia such as ropes, lines and nets. Food
wrappers and plastic bottles were also common. The plastic constitutes an
“emerging threat” to reefs already stressed by the climate crisis and
overfishing, the researchers said.
The study, Plastic Pollution on the World’s Coral Reefs
, examined 85 reefs at
more than two-dozen locations – including uninhabited atolls and reefs at
depths of 150 metres – across the Indian, Pacific and Atlantic. It brought
together scientists from the California Academy of Sciences; the foundation and
charity Nekton; and the universities of São Paulo, Oxford and Exeter.
The scientists used special diving equipment to survey in “mesophotic”, or
twilight, zones at 30-150 metres (100-490ft) beneath the surface, and
discovered the deeper sites had more plastic than the shallower ones.
“It was surprising to find that debris increased with depth, since deeper reefs
in general are farther from sources of plastic pollution,” said Luiz Rocha, the
co-director of the Hope for Reefs initiative at the California Academy of
“We are almost always the first humans to set eyes on these deeper reefs, and
yet we see human-produced trash on every dive.”
There was more plastic pollution in reefs nearer to densely populated cities
and markets, as well as marine protected areas, whose borders are heavily
frequented by fishers.
The researchers noted that plastic can spread coral disease, and that fishing
lines and nets can damage the structure of the reefs and thus harm fish
abundance and diversity."
*** Xanni ***
Chief Scientist, Xanadu
Partner, Glass Wings
Manager, Serious Cybernetics