ENVIRONMENT
PLASTICS ALL AT SEA
PICTURE/TIHOMIR MAKOVEC I
mages of turtles trapped in plastic packaging or a fish nibbling on microfibres pull on the heartstrings.
Yet many scientists studying plastics in the oceans remain open-minded on the long- term effects. While plastics shouldn’t be in our oceans, they say there is still insufficient evidence to determine whether microplastics – the very tiniest plastic particles, usually defined as being less than 1mm in diameter – are actually harmful.
Microplastic particles are accumulating in our seas, but does anyone really know how much is out there – or whether they are harmful? Lou Reade reports
On top of this, there is debate over how much plastic is actually in the sea and why so much of it remains hidden from view. Much of the research carried out to date is in its early stages – and has so far produced no definitive answers. ‘My concern is that we have
to provide the authorities with good data, so they can make
good decisions,’ says Torkel Gissel Nielsen, of the Technical University of Denmark (DTU). ‘We need strong data – and not just emotions.’
Gissel Nielsen leads a team of
researchers who have discovered that levels of microplastics in the Baltic Sea have remained constant over the past three decades, despite rising levels of plastics production and use. The study – by researchers at DTU Aqua, the University of Copenhagen and Geomar in Germany – analysed levels of microplastics in fish and water samples from the Baltic Sea, taken between 1987 and 2015 (Science of the Total Environment;
doi.org/10.1016/j. scitotenv.2017.10.101). ‘The result is surprising,’ says Nielsen. ‘There is the same amount of plastic in both the water and the fish when you go back 30 years.’ He claims that previous studies of microplastics levels were ‘snapshots’, while this is the first time levels have been studied over a longer period. ‘The study raises a number of questions, such as where the plastic has gone,’ he says. ‘Does it sink to the bottom, are there organisms that break it down, or
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