Plastic Pollution: A Silent Killer of Ocean Embryos

From discarded packaging to fishing gear, an estimated 11 million metric tonnes of plastic waste enter our ocean each year.[1] Plastic pollution has become a global environmental crisis, permeating every corner of the ocean with devastating consequences for marine ecosystems. These pollutants also persist for hundreds of years, accumulating in marine environments.[2] Marine organisms are increasingly exposed to the harmful effects of plastic at all stages of life.

Estimated number of years for selected items to bio-degrade in marine environment (Image source: Statista)

Plastic debris in the ocean pose various threats to marine animals. The more obvious come in the form of entanglement, suffocation, and destroying habitats.[3]Smaller plastic pieces, including microplastics (particles less than 5 millimeters in size), can be mistakenly ingested as food, causing internal injuries or slowly starving them to death.[4] Even more worryingly, we now find increasing evidence that marine plastics can leach chemicals which can disrupt the embryonic development of marine life.[5]

Sea turtle entangled by plastic netting (Image source: ScienceWorld)

 Microplastics on the beach (Image source: Oregon State University)

Researchers at the University of Exeter recently found exposure to high concentrations of PVC pellets prevented healthy development in seven species, covering all major ocean animal groups.[6] Plastic leachate exposure has been found to affect mainly embryo axial formation, cell specification, and morphogenesis—the biological process which governs the formation and differentiation of tissues and organs. The new findings correspond to an older research which saw exposure to plastic leachate causing deformities in sea urchin larvae.[7]

Plastic pellet leachates affect a large swathe of animal phyla (Image source: Jimenez-Guri et al.)

The ramifications to the population health and marine ecosystem cannot be understated. Of particular concern are the impacts it has on coastal species, as they reside near beaches and rivers—known hotspots for plastic pollution.[8]

To stem the flow of plastic waste into our ocean, we need concerted efforts at all levels. Effective waste management strategies, education and public outreach, reducing plastic usage, and promoting circular economy practices are essential steps to achieving this. Hong Kong joining the global move to ban disposable plastic tableware and other plastic products is commendable.[9] However, with the increasing prevalence of online shopping, the government needs to expand regulatory efforts to include plastic packaging for logistics and online shopping as well.[10]

Online shopping creates excessive packaging waste (Image source: China Daily)

By taking immediate action to combat plastic pollution, we can help safeguard the diversity and resilience of marine life, ensuring a healthy and thriving ocean for future generations.