Towards a baseline for microplastics contamination in Scottish intertidal sediments for regulator purposes

Microplastics (MP), defined as pieces of plastic < 5mm, are commonly found in the marine environment and originate either from consumer care products and plastic production plants or from the disintegration of larger pieces. MPs need to be monitored in order to evaluate the effectiveness of Government initiatives to reduce plastic debris in the environment. Whilst this is well established for marine litter, hitherto a quantitative long-term marine MP baseline database is lacking. I will present the results of a five-year pilot project in the Firth of Forth, point to innovations in sampling and contamination prevention, as well as the limitations of this approach. The MP concentrations in intertidal sediments in the Firth of Forth have remained largely stable during the monitoring period. This is significant baseline information and will be instrumental in assessing the effectiveness of Government policy regulating the use of particularly single-use plastic products. However, in order to compare results between countries and laboratories, for the purpose of gaining a more global insight into the microplastics contamination issue, more standardized sampling and extraction procedures need to be developed.