Marine animals may be more likely to eat biodegradable plastics than conventional plastics, according to a study of crabs and worms on a beach in Australia. The findings suggest that increasing biodegradable plastic use could harm wildlife more than anticipated.
Plastic pollution is a pervasive global issue, with millions of tonnes ending up in the environment every year. It also poses a risk to wildlife, with finding it harms the fertility and metabolism of some species.
Biodegradable plastics 鈥� or bioplastics 鈥� which are usually derived from organic sources, such as seaweed or even squid teeth, are touted as a possible solution to the problem. But not much is known about how marine life interacts with them, says at the University of Queensland in Australia.
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To address this, Mos and Sandra Powell, also at the University of Queensland, tested how fishing lures marketed as made from either biodegradable, semi-biodegradable or normal plastic fared in seawater for two weeks.
Biodegradable lures fluctuated in weight dramatically 鈥� increasing or decreasing by 70 per cent due to changes in their water content. In comparison, the semi-biodegradable and normal lures only showed slight fluctuations in weight.
鈥淚f fish eat the lure and it swells in the body, it could potentially block their guts,鈥� says Mos.
The researchers then exposed beach-dwelling soldier crabs (Mictyris longicarpus) and green paddle worms (Phyllodoce novaehollandiae) to the three types of lures for 48 hours. They found that both animals almost exclusively ingested the biodegradable lures, with the crabs also eating a small amount of the semi-biodegradable lures.
鈥淏ioplastics by their very nature are a type of organic material, and that makes them potentially attractive as food,鈥� says Mos.
Though the full impact of bioplastics on health is unknown, research shows that they can contain a , including those that have adverse effects on wildlife and the environment, says at the University of Plymouth, UK.
鈥淚t is essential that we reduce the production and use of all plastics, regardless of their carbon source, or whether or not they are 鈥榖iodegradable鈥�, rather than switching to plastic alternatives or substitutes,鈥� she says.
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