Plastic nurdles on uShaka beach in Durban.

A documentary on the Carte Blanche TV show last year featuring UKZN researchers has proved relevant in terms of warning of the dangers of microplastic spills following the devastating storm which struck greater Durban on 16 October this year.

The show – which contained interviews with postgraduate students from the University’s Marine Biology, Aquaculture, Conservation Education and Ecophysiology (MACE) Laboratory – received a merit award at the recent 29th Annual SAB Environmental Media and Environmentalist of the Year Awards.

According to Dr Deborah Robertson-Andersson, who heads the MACE Lab with Mr Gan Moodley, the microplastic spill ranks third or fourth globally in terms of magnitude. It is estimated that the billions of nurdles (the raw material in plastic manufacturing) which spilled from two containers could contaminate the coastline as far north as Richard’s Bay.

This poses a dire threat to marine life and in turn humans as the nurdles never fully disintegrate, and release and attract dangerous chemical pollutants, making them up to one million times more toxic than the surrounding water. According to Moodley, as marine life consumes the plastic, mistaking it for food, not only do the animals starve, but the effects of the toxic plastic is multiplied up the food chain as contaminants accumulate, affecting the health and fertility of larger predators.

Microplastics are particles smaller than 5mm long (too small to be filtered out at sewage plants) that are either manufactured to this size as nurdles, or broken down from larger plastics. By 2050, scientists predict there will be more plastic in the ocean than fish, affecting up to 90% of sea birds. Plastic takes hundreds of years to degrade and once washed out to sea collects in five major gyres worldwide.

In the Carte Blanche programme, reporters spoke to postgraduate students Mr Sipho Mkhize, Ms Kaveera Singh, Ms Gemma Gerber and Mr Mathew Coote about their research.

Mkhize dissected a fish caught in the Durban harbour, demonstrating the extent of the microplastics in its stomach; Singh discussed finding nylon clothing fibres in the Umgeni River, and Gerber spoke about the impact of microplastics on mussels, an important local food source.

MACE researchers have found that 30% of fish they study contain microplastics which also occur in beauty and household products and synthetic fibres released from clothing in washing cycles. As beauty and cleaning product additives, they are banned in several countries, but not in South Africa.

The MACE team is involved in several beach clean-up events, collecting data and partnering with Durban Umgeni Conservation Trust (DUCT) and Paddle for the Planet to clean up river systems and remove plastic waste before it reaches the ocean. The team is raising awareness through publicising its research and was also featured in a SABC-TV 50/50 Earth Day segment in 2016.

Words: Christine Cuénod

Photograph supplied by Deborah Robertson-Andersson; courtesy of the South Coast Sun