Plastic Pollution Crisis Unveiled in Cape Town's Table Bay

Marine and coastal environments are facing unprecedented challenges due to the presence of litter, mesolitter, and microplastics. This study investigated the characteristics and distribution of litter, mesolitter (2-25mm), and microplastics (MPs; <5mm) in beach sediment and MPs in seawater samples from Table Bay, Cape Town. Samples were collected from two sites: Woodbridge Island and Derdesteen. The research provides critical insights into the scale and nature of plastic contamination in this vital South African coastal region.

Researchers conducted sampling over 10 consecutive days during summer and autumn, collecting a total of 11,179 litter items and 1,428 mesolitter pieces, alongside extracting 688 microplastics from water and sediment samples. Plastic was identified as the most abundant material across the litter and mesolitter categories. Plastics accounted for 90% by count in collected litter, with foam (mainly polystyrene) being the most abundant plastic type found. Plastic pellets were the dominant mesolitter type, while fibrous MPs dominated the extracted MPs, primarily blue in color. Advanced analysis of plastic mesolitter identified polyethylene (PE: 60%) and polypropylene (PP: 27%) as the dominant polymers.

A significant disparity in pollution levels was observed between the two sites, with Woodbridge Island experiencing substantially higher concentrations of all three contaminant categories compared to Derdesteen. This difference is directly attributed to elevated anthropogenic inputs at Woodbridge Island. Sources of this pollution are diverse, ranging from beachgoers, residential and commercial inputs, and maritime operations, to recreational activities and tide pooling.

As lead author Bukasa notes in the paper, "Our study highlighted plastics as a significant component of marine litter, and the prevalence of polyethylene and pellets in mesolitter highlights the urgent need for preventive measures and sustainable clean-ups, to mitigate the short- and long-term impacts of plastics on the marine ecosystems and biodiversity." These findings from Table Bay starkly illustrate the predominant role plastics play in marine litter and underscore the severity of the issue, calling for immediate and comprehensive action to protect the region's delicate marine ecosystems and rich biodiversity.