Worms help reveal plastic woesLocal | Stella Wong 6 Mar 2018
The growth and development of two marine invertebrates suffer irreversible damage under exposure to high concentrations of microbeads, a research team at the Hong Kong University of Science and Technology has found.
The research team discovered that tiny plastic pellets of less than five millimeters in diameter, found in many health, beauty and household products, are not confined to only upscale, commonly consumed marine organisms like abalone and oysters.
But they also take a toll on the pollution-tolerant slipper limpets and bristle worms, which are commonly used as fish bait.
"Both organisms are ecologically and commercially important," said Karen Chan Kit-yu, an assistant professor at the university's Division of Life Science.
She said bristle worms play an important role in nutrient cycling. The study found that under a high concentration of microbeads, the regeneration ability of the worms segment would be impaired and threaten their lives.
The study also showed that slipper limpets, an invasive species that originated from California and found in Victoria Harbour, are vulnerable to long-lasting and irremediable negative impact from a high concentration of microplastics.
Although these snails are unfazed by microplastics at an environmental concentration found in Hong Kong waters, they could threaten the survival of the local species, as well as ecological balance.
Chan also said that since both species belong to the lower level of the food chain, a decrease in their population might affect their predators, and even pose a negative impact on the ecosystem on a macro scale.
"Despite all the adverse impact that these plastic pollutants have on the marine ecosystem, they are still being used in many personal care products around the world, including Hong Kong," she said.
Some countries, such as Canada, have banned the use of microplastics, but they remain legal in many developed countries.
Chan urged Hongkongers to avoid products with microplastics and to think twice before using single-use plastics, such as straws and bottled drinks, as microplastics degrade into smaller pieces.