Microplastics pollution in the Greater Bay Area: distribution and impact

Abstract

Plastic pollution of coastal environment is one of the most pressing issue of our modern society as its linked to our lifestyle and our capacity to develop efficient waste management. Based on the population and waste management practices around the Greater Bay Area (GBA), researchers recognised the Pearl River has a key location for plastic release into the Ocean1. Using data on microplastic abundance around the Pearl River Delta collected during the last three years we investigated the regional distribution and its impact on the marine environment. We estimated macro and microplastics abundance and distribution in Hong Kong waters and beaches in order to understand the parameters responsible for their presence. We observed a higher abundance of microplastic after rainfall events, however no specific types of plastics were preferentially accumulated suggesting that plastic waste mismanaged are washed up into the river and/or oceans. When looking at the plastic abundance in nearshore waters, we observed a significant accumulation of both macro and microplastics at the breaking wave area. More particularly we observed that highly buoyant plastics as expanded polymer preferentially accumulated at breaking wave area, indicating the importance of plastic polymers in microplastic pieces behaviour and distribution in the marine environment. Finally, we look at the ingestion of microplastics by marine organisms as benthic fish and mangrove crabs and we highlighted that more than half of the individual collected had ingested microplastics. The GBA is under an increasing pressure in term of plastic pollution and marine organisms are already affected by it, therefore it is crucial to develop efficient waste management strategies to limit microplastics input into the GBA coastal waters.