A major research project has shown that masses of plastic waste has caused the sand on two isolated island beaches to warm by almost 2.5 degrees Celsius, with potentially dire consequences for the coastal species that occupy, feed, and produce offspring on the shore.
Researchers from the University of Tasmania’s (UTAS) Institute of Marine and Antarctic Studies and the Natural History Museum in London measured sand temperatures across six sections of Henderson Island in the South Pacific and Australia's Cocos Keeling Islands.
The study’s lead author, Jennifer Lavers from UTAS, said accumulated plastic that washed up on the island’s shores over years has acted as an insulator and altered how much light, wind, and moisture can be absorbed by the sand.
As much as 3 kilograms of plastic per square metre was uncovered on some of the beach's surfaces.
"If we have plastic piling up, drastically changing the temperature of that sand, that temperature is no longer tolerable to the meiofauna,” Lavers told the ABC.
Meiofauna are tiny organisms that live along the seaside and within sandhills. Small crabs, worms, and other meiofauna are a vital food source for birds that have lived on the islands for hundreds of years.
Alongside affecting meiofauna, rising temperatures will also affect sea turtles because they are temperature-dependent, Lavers explained, meaning the warmth of the sand determines whether an egg will be male or female.
Separate research in 2019, meanwhile, revealed plastic pollution on the islands caused the deaths of half a million hermit crabs, according to the Guardian.
‼️ BREAKING ‼️— Prof Brendan Godley (@BrendanGodley) May 25, 2021
Plastic debris raises sand temperature threatening #turtle populations🆘
Pacific island study led by @SeabirdSentinel find #plastic#pollution acts as an insulator - making sand hotter - resulting in more female offspring🐢👎
Every year, the world produces 380 million tons of plastic, half for single-use purposes. More than 10 million tons of this plastic enters the world’s oceans each year.
Despite nations like Australia, Canada, China, and England introducing strict single-use plastic bans, global plastic production continues to increase, which, according to Lavers, will only mean more and more plastic ending up in the sea and on the shores of beaches across the world.
“With global plastic production currently doubling almost every decade, and much of the plastic debris that accumulates in our oceans eventually making its way onto beaches around the world, the low and moderate debris loads we observed on Henderson and Cocos are likely to transition to high debris over the next few decades,” Lavers said in a media release.
Lavers said further research and immediate action to limit plastic waste is vital.
“Clearly, further study into the physical impacts of plastics on ecosystems is needed to understand the severity and scope of these issues, but we also need to make significant shifts in how we produce and manage plastic waste — and we need to do it urgently,” she said.