Microplastics in the Scottish marine environment: a call for greater clarity



A Heriot-Watt research team has produced a Government report looking at the levels of tiny particles of plastic on the Scottish marine environment.

“We simply don’t know what sort of concentrations of microplastics exist in Scotland’s waters right now.”
Dr Mark Hartl

The report, commissioned by Scotland’s Centre of Expertise for Water (CREW), considers the existing level of knowledge about microplastics, tiny particles of plastic less than five millimetres across, and other synthetic materials which are known to exist in the marine environment.

There are increasing concerns about what effect this contamination is having. But the Heriot-Watt team, led by Dr Mark Hartl, Associate Professor of Marine Biology in the School of Life Sciences, says that a major problem for decision makers is the lack of basic information about how severe the contamination is currently, so that they can measure the effects of any attempts to mitigate its spread.

They call for studies to establish such baseline information. “Litter in the environment is not a new phenomenon. However, the realization that microscopic plastic particles and synthetic microfibres are present in the aquatic environment has recently drawn a lot of public attention.

“One particular concern is growing evidence for the ability for microplastics to move up the food chain, possibly in increasing concentrations, and therefore potentially to affect human health.

“There are a number of gaps in our knowledge of the effects of these microparticles which scientists, including my colleagues at Heriot-Watt, are working to explore. But for decision makers a very basic problem is that we simply don’t know what sort of concentrations of microplastics exist in Scotland’s waters right now, and this makes it very difficult to measure the success or otherwise of attempts to mitigate the problem. Attempts like charging for plastic carrier bags. We know that it has reduced the number of bags used and thus presumably discarded, but will such actions have a measurable effect on the number of microparticles in Scotland’s water?”