Microplastics Found in Fish off KZN Coastline

BY: .

A research study by Deborah Robertson Andersson and Gan Moodley of the University of  KwaZulu-Natal’s School of Life Sciences has shown that microplastics are increasingly being ingested  by fish off the KwaZulu-Natal coast.

So think twice next time you use a facial or body scrub. You could end up eating it. Many facial and body scrubs contain microplastic beads.

‘Those are the scrubbers,’ said Jone Porter, Director of Sea World Education at uShaka Marine World. ‘And more and more guys are using them too.’

The sewage system cannot handle microplastics so they are eventually washed out to sea and eaten by fish.

‘One fish eats another fish and so on, and the microplastics accumulate up the food chain,’ said Porter. ‘The sardines and anchovies we eat have small stomachs and we eat these, so we are eating microplastics.’

According to the UKZN study, fish species taken from Durban Harbour, Vetch’s Pier, Isipingo, uMngeni and Mdloti river mouths contained microplastics. These included horse mackerel and mullet.

‘Plastics take three to four times longer to pass through a fish’s gut,’ said Robertson Andersson.

‘The fish feels fuller and eats less. It may also use more energy pushing plastic through the gut and might also get blockages.’

The microplastics also attract persistent organic pollutants (Pops) that are known to have an adverse effect on human health. ‘The longer time in the gut allows the Pops to jump off and accumulate in fish.’

And when humans eat the fish? ‘It’s bad,’ said Robertson Andersson. ‘But we are not sure how bad. It’s early days yet and we are not certain what the effect is.’

Not all microplastics come ready made, they are also created by the fragmentation of larger plastic items that are gradually broken up by ultraviolet rays and wave action.

According to Porter, every large plastic item will become a microplastic.

‘They get brittle, break up and get smaller and become “plastic soup”—it’s a global problem.’

‘Fish, turtles and dolphins will eat a lot of plastics. Fish think microplastics are fish eggs, while species like turtles that eat jelly fish see plastic bags floating in the water as jelly fish.’

Porter said turtles have ‘hooks’ in their throats pointing downwards that help them swallow. ‘They are not able to regurgitate and plastic doesn’t go through their digestive system. It builds up in their stomach - they feel full and no longer eat. They literally starve to death but don’t realise it.’

Porter said that on two occasions turtles have died at the uShaka Sea World Rehabilitation Centre and when autopsied ‘were found to be packed with plastic’.

‘Anyone who takes a walk along our beaches can see we have a problem,’ said Porter. ‘We need to get away from the total throwaway concept.’

Courtesy of Stephen Coan, Natal Witness