It’s hard to picture a more pristine coastline than the towering, green cliffs being battered by the rough breakers of South Africa’s Wild Coast.
But though it may seem unspoiled, researcher Vonica Perold has come to learn there is no patch of ocean left that is untouched by human activity.
Perold is on board the flagship research vessel – the SA Agulhas II – taking water samples along the continent’s east coast as part of the second International Indian Ocean Expedition. She is hoping to find out how much plastic waste is floating around in southeast African waters. But though she is yet to put a single sample under the microscope, her experience leaves her in little doubt about what she will find.
Microfibres – tiny plastic strands from synthetic clothing – are now omnipresent. And just because they’re not unsightly, like large pieces of trash, researchers are starting to fathom their far-reaching impact on the environment.
“We’ve been finding it in water around Antarctica, in the South Atlantic – everywhere – so we do expect to find it. How much, we’re not sure – that’s why we’re doing these tests, but we will find it, definitely.”
Perold, who is employed at the University of Cape Town’s FitzPatrick Institute of African Ornithology, had originally planned to become a biologist. But a year-long stint on Marion Island in the southern Indian Ocean altered her career path. The abundance of man-made waste so far from civilisation came as a shock to the young researcher, and it was here that her eyes “opened to the plastic pollution problem.”
“We found plastic in the albatrosses’ nests right next to these beautiful chicks and that was just heart-breaking, because it’s 2 000km from Cape Town, in the middle of the open Southern Ocean,” she explains.
Researchers have divided plastic litter into three categories, according to size: macroplastics (pieces you can see with the naked eye); mesoplastics (smaller fragments between 5-20 mm); and microplastics (pieces smaller than 5mm). The latter includes fragments that were once part of larger pieces: raw pellets known as nurdles and microfibres.
Each of the size categories holds distinct threats to living organisms. The larger pieces, such as discarded fishing gear, regularly entangle marine animals, whereas smaller pieces are ingested because they often look like food. Turtles, for example, are known to eat plastic bags, mistaking them for jellyfish.
“It’s a terrible death because they can’t excrete it,” Perold explains.
“It ends up in their intestines, in their cloaca, blocking their whole gastrointestinal tract and, really, it’s a painful death.”
While they are almost invisible, scientists have started acknowledging the serious effects of microplastics on the environment. These materials are ingested by the smallest sea creatures and may travel all the way up the food chain to humans. The long-term consequences are not yet known, but the chemicals that are absorbed to the surface of marine litter can be dangerous to human and animal health.
Back in a lab at the University of Cape Town, Perold is helping the director of the Fitzpatrick Institute – Professor Peter Ryan – with the grim task of dissecting a pile of dead seabirds.
He picks up a white-chinned petrel – one among thousands he has processed in his career. These birds spend most of their time in the Southern Ocean, far from cities and human settlements. But even they do not escape our impact on the marine environment. Vast numbers are killed when they get caught while trying to snatch the bait off longline fishing hooks.
Sad as it may be, these deaths present an opportunity for Ryan and his team. The stomach contents and tiny gizzards hold a treasure trove of information – an indication of how much plastic the animals have ingested.
Petrels are not known as the most prolific plastic eaters, Ryan says, so he is surprised when tell-tale blue and green fragments protrude from the bird’s small gizzard. The contents are extracted and logged. Although it’s not the plastic that killed this specimen, it is not hard to imagine what happens when an anima keeps ingesting material it cannot digest or excrete.
“If they really have a lot of plastic, so that it starts to fill up the fore stomach, then it reduces their ability to eat – so they get this false feeling of satiation and when they do find something they can’t eat as much in a single sitting… so if they’ve got a stomach that’s really full of plastic then that obviously is a significant problem for them,” Ryan explains.
The other issue relates to the contaminants that come with plastics.
“So, plastics that float around at sea, they act as little sponges and accumulate legacy pollutants like PCBs and DDT and those really horrible things that we banned, but are still around in the environment. And because they absorb those plastics when the birds eat them, there’s a mechanism for them to actually be released into the body of the bird. And then some plastics… if you’re using plastics in a sort of long life application, you often put additives in to give them specific properties – like maybe flame retardants or something – and those can be quite nasty compounds, hormone disruptors and carcinogens and things…”
While the situation may seem impossibly depressing, Ryan has taken heart from his latest study examining plastic debris on South African beaches.
Three surveys – in 1994, 2005 and 2015 – saw Ryan and his team sieve samples of sand from 82 beaches, and count mesoplastic debris between 1-25 mm in size, in order to determine the patterns in abundance and distribution of small plastic items. The results suggest where most of the plastic in South Africa’s marine environment comes from.
The study came to a startlingly positive conclusion.
Unlike some islands, where plastic from unknown origin accumulates, Ryan and his team determined much of the litter on South African beaches comes from local sources.
“This is good news, because we will benefit from local actions,” he explains.
We don’t have to wait for people in the northern hemisphere or Asia to change their behavior to improve the status of our coastal waters and beaches. It also means that we can monitor whether our mitigation actions are having real benefits.”
But, he stresses, enormous challenges remain.
“All available evidence indicates that the amounts of litter entering the system continue to grow. We need a complete overhaul of solid waste management in South Africa, from government to grassroots levels.”
Probably the biggest failing occurs at municipal level, where there is whole inadequate waste management. A recent study estimated that more than half of the solid waste in SA is mismanaged (compared to 12% in Brazil and 2% in the USA).
But central government also has a key role to play through setting policies that promote reduction of plastics in the packaging stream, and requiring producers to take responsibility for their packaging beyond the point of sale (so-called Extended Producer Responsibility).
Consumers can play a big role by demanding better packaged items, and appropriate mechanisms to recycle or reuse their packaging. And the retailers have a strong role as a choke-point in the supply chain, who can effect wide-ranging changes.
“We just need the motivation to act. Marine litter is a wholly avoidable problem, and this study shows that it is one that largely rests within our own control.”
By Aletta Harrison. Source: News24