Ranging from discarded nets and cups to plastic bags and other debris, indeed, the ocean floor has tragically become a garbage bin for a vast array of plastic pollution. The accumulation of such waste has reached alarming levels, with estimates suggesting that between 3 to 11 million tonnes of plastic now rest beneath the waves, leaving marine life gasping for breath.
The staggering heap of plastic pollution on the ocean floor has been revealed in a study conducted by scientists from CSIRO, Australia’s national science agency, and the University of Toronto in Canada. With plastic use expected to double by 2040, the situation is set to choke marine ecosystems and wildlife.
Dr. Denise Hardesty, Senior Research Scientist at CSIRO, emphasizes the gravity of the findings, stating that while millions of tonnes of plastic enter the oceans annually, the extent of plastic accumulation on the ocean floor was previously unknown.
She underscored the ocean floor’s role as a resting place or reservoir for plastic pollution, highlighting the urgent need for action to mitigate its impact.
Alice Zhu, a PhD Candidate at the University of Toronto and lead researcher, indicated that the amount of plastic on the ocean floor could be up to 100 times greater than that observed floating on the ocean’s surface.
She emphasized that even if plastic input into oceans were halted, plastic would continue to accumulate in the deep ocean, presenting a long-term environmental challenge.
The study utilized scientific data to develop predictive models estimating the distribution and quantity of plastic on the ocean floor.
These models, based on data from remote operated vehicles (ROVs) and bottom trawls, revealed that plastic mass tends to cluster around continents, with a significant portion residing at depths exceeding 200 meters.
The article, ‘Plastics in the deep sea – A global estimate of the ocean floor reservoir,’ was published in Deep Sea Research Part I: Oceanographic Research Papers.
Remarkably, inland and coastal seas, though covering less surface area than oceans, are predicted to harbor a comparable amount of plastic mass.
The study concurs with the observation of the International Union for Conservation of Nature (IUCN), an international organization working in the field of nature conservation and sustainable use. “At least 14 million tons of plastic end up in the ocean every year, and plastic makes up 80% of all marine debris found from surface waters to deep-sea sediments.
“Marine species ingest or are entangled by plastic debris, which causes severe injuries and death.
Plastic pollution threatens food safety and quality, human health, coastal tourism, and contributes to climate change,” says the IUCN.
Under the influence of solar UV radiation, wind, currents and other natural factors, plastic breaks down into small particles called microplastics (particles smaller than 5 mm) or nanoplastics (particles smaller
than 100 nm).
The small size makes them easy for marine life to ingest accidentally, the IUCN notes, calling for new and existing legally binding agreements to address marine plastic pollution.
