Australian researchers have estimated how much plastic is on the ocean floor, finding that a garbage truck’s worth of plastic enters the ocean every minute.
A joint study between Australia’s peak science body the CSIRO and Canada’s University of Toronto found up to 11 million tonnes of plastic could be sitting on the ocean floor.
Researchers said global waste and “the exponential increase in plastic production” has resulted in “large amounts of plastic waste entering the ocean every year”.
Plastic waste
There are two major types of plastic ocean pollution — small plastic particles (microplastics), and larger objects like bags, nets and cups (macroplastics).
Macroplastics eventually break down into microplastics.
This latest data gives researchers an insight into the scale of larger plastic waste at the bottom of the ocean for the first time.
Findings
The CSIRO and University of Toronto study sent remote-operated vehicles (ROVs) to the ocean floor to collect data.
Using ROV data, researchers estimated that between three and 11 million metric tonnes of plastic pollution has settled on the ocean floor.
The findings show mass clusters of plastics appear to be gathering closer to human populations rather than in more isolated, deeper parts of the ocean.
“We discovered that the ocean floor has become a resting place, or reservoir, for most plastic pollution,” senior CSIRO scientist Dr Denise Hardesty said.
The CSIRO expects plastic use to double by 2040. It said understanding how and where it travels in the ocean is “crucial to protecting marine ecosystems and wildlife”.
The University of Toronto said the findings will help “fill a longstanding knowledge gap on the behaviour of plastic in the marine environment”.
