A huge mass of plastic floating in clear water at a popular Indonesian dive site has been filmed by a diver who said he had never seen "anything on this scale" of ocean pollution.
In a video uploaded to social media, diver Rich Horner is seen swimming through masses of floating plastic garbage at a dive site frequented by stingrays coming to clean up.
Although the dive site is located off the coast of Nusa Penida, a small island with little population, there is a stretch of only 20 kilometers of water that separates Nusa Penida from the island of Bali and its capital, Denpasar.
"Plastic straws, plastic baskets, plastic bags, more plastic bags, plastic, plastic, so much plastic!" Horner wrote on Facebook.
"Surprise, surprise. There weren't many blankets there at the cleaning station today. They mostly decided not to bother. "
Mr. Horner said that the level of plastic at that site varied throughout the year, with no plastic visible during the dry season, but clouds and patches appear randomly during the wet season.
He said that this trash in the pictures was gone the next day.
A new study by researchers from Australia, Italy and the US has found that tiny plastic particles are a particular threat to "filter-feeders" such as stingrays near Bali, which can swallow up to 90 pieces every hour.
Elitza Germanov, principal investigator at Murdoch University, told ABC News microscopes that particles less than five millimeters long contain toxic chemicals that, if ingested, could alter biological processes in animals, such as growth, development. and reproduction.
"We are still trying to understand the magnitude of the problem," said Ms Germanov.
"Microplastic contamination has the potential to further reduce the number of populations of these species, many of which are long-lived and have few descendants throughout their lives."
Once this trash ends up in the ocean and is washed away by currents, it is virtually unrecoverable.
Exposed to salt water, sunlight, and heat, larger pieces of plastic eventually break down into smaller and smaller pieces.
Marine filter feeders like manta rays, whales, and whale sharks are at risk due to their eating habits.
Thousands of cubic meters of water are swallowed per day to capture plankton and other tiny organisms that float in the sea.
Ms Germanov, who is in the final stages of a PhD project through Murdoch University, is focusing on plastic pollution in stingray feeding areas around the coast of Nusa Penida and Komodo National Park in Indonesia.
"Plastics are definitely on the menu here," he said.
"Our first results indicate that the blankets ingest 40 to 90 pieces of microplastics per hour."
With the help of a team of local researchers from Udayana University in Bali, she is also collecting samples of egenated material and stomach contents from animals to study their exposure to plastic-associated toxins.
In a final step, the team is conducting a social study, questioning local communities about their awareness of the issue.
"Raising awareness on this issue in communities, among government bodies and industries could help change behaviors around the production, management and use of plastics," said Ms Germanov.
Janis Argeswara, a marine science student at Udayana University, said she was surprised by stingrays swimming in a "garbage pile."
"Bali's economy relies heavily on tourism for income," he said.
"If the blankets disappear from Nusa Penida, the people here would not know what to do."
While Southeast Asian waters are some of the hardest hit in terms of plastic waste, garbage is also entering Australian waters.
Researchers have long found a microplastic hotspot near the World Heritage site Ningaloo Reef, famous for its whale shark encounters.
"The plastic beads in face scrubs and toothpastes, which are too small to leak during water treatment, are another factor in contamination," said Ms Germanov.
The world's largest fish, the whale shark, is listed as vulnerable on the International Union for Conservation of Nature's Red List, with just 7,000 species remaining in 2016.
Original article (in English)