In collaboration with the University of Toronto in Canada, new research from CSIRO, Australia’s national science agency, reveals a staggering statistic: the ocean floor is concealing up to 11 million tons of plastic debris.
The rate at which plastic enters our oceans is alarming, equivalent to disposing of one garbage truck’s load every minute. Projections suggest that plastic use could double by 2040, underscoring the urgent need to understand how plastic navigates marine environments to safeguard the fragile ecosystems.
Denise Hardesty, Senior Research Scientist at CSIRO and co-author of the study, emphasized, “We know that millions of tons of plastic waste enter our oceans every year but what we didn't know is how much of this pollution ends up on our ocean floor." The research revealed that the ocean floor is a reservoir for a significant portion of plastic pollution, with estimates ranging from 3 to 11 million tons, encompassing various items from nets to plastic bags.
Lead researcher Alice Zhu, a PhD candidate at the University of Toronto, highlighted the enormity of the plastic problem, indicating that the amount of plastic on the ocean floor could surpass surface levels by up to 100 times. Zhu explained, "The ocean surface is a temporary resting place of plastic so it is expected that if we can stop plastic entering our oceans, the amount would be reduced. However, our research found that plastic will continue to end up in the deep ocean, which becomes a permanent resting place or sink for marine plastic pollution."
To comprehensively assess the distribution of oceanic floor plastic, the research team developed predictive models utilizing data from remote operated vehicles (ROVs) and bottom trawls. Findings revealed that plastic tends to aggregate around continental masses, with almost half located above 656 feet depth and the rest distributed in deeper waters, down to approximately seven miles.
Despite inland and coastal seas covering only 11% of the Earth's total area, they contain an equivalent amount of plastic mass as the rest of the oceanic floor combined.
Zhu reiterated, "The ocean surface is a temporary resting place of plastic so it is expected that if we can stop plastic entering our oceans, the amount would be reduced." She emphasized the need for a better understanding of plastic behavior in marine environments to inform source reduction and environmental remediation efforts, thereby mitigating the risks posed by plastic pollution to marine life.
The impact of plastic pollution on ocean ecosystems is profound and multifaceted, affecting various marine organisms. From entanglement and ingestion to toxicity and habitat disruption, plastic pollution poses significant challenges to marine life and ecosystems. Additionally, the economic impacts are substantial, affecting industries such as tourism, fishing, and shipping.
