Plastic plankton: Long term study of zooplankton’s microplastics uptake in the Northumberland coast

The Microbiology Society is undertaking a project entitled A Sustainable Future as part of our 75th Anniversary, which aims to highlight the Sustainable Development Goals (SDGs) to our members and empower them to use their research to evidence and impact the goals. Earlier this year, we put a call out to our members to submit case studies in the following three areas: antimicrobial resistance, soil health and the circular economy.

This case study is written by Dr Priscilla Carrillo-Barragán, a Research Associate at the Dove Marine Laboratory, Newcastle University, UK. It focuses on the circular economy; an alternative to a traditional linear economy (make, use, dispose), in which we keep resources in use for as long as possible, extract the maximum value from them while in use, then recover and regenerate products and materials at the end of each service life.

The North Sea is an environment full of valuable resources surrounding the coasts of north-west Europe and, as such, suffers from numerous anthropogenic impacts, one of them being the steadily increasing input of plastic waste. In fact, the dimension of the global plastic pollution problem, to which Europe contributes to about 20%, has caused great public concern, pushing governments and industries to act.

Among the many detrimental consequences of plastic litter, its consumption by marine biota is of particular relevance for the North Sea, as this is one of the world’s richest fishing grounds. Of further concern, is the estimated longevity of the discarded plastics, ranging from months to thousands of years, therefore being potentially available for consumption for an indeterminate amount of time. Although several reports of plastic debris uptake and their effects on the marine biota are now available, the variability of the methods used and the temporality of the results obtained make it difficult to establish a clear picture of the current state of the microplastic pollution problem in the North Sea.

Since the beginning of the 20th century, monitoring plankton groups variations in space and time has been used as an important tool to assess the health of the ocean to such an extent that international standard procedures to do so exists (UNESCO, 1968). Therefore, building from existing infrastructure to inform future policy and pollution monitoring efforts, our aim is to determine the presence and prevalence of microplastics ingested by zooplankton in the UK’s north-east waters over the past 50 years.

We are studying samples (ranging from 1971 to 2020) from the Dove zooplankton Time Series (DTS), an ongoing monthly collection of zooplankton at a station in the central-west area of the North Sea, approx. 10 km of the Northumberland coast, UK. Specimens of decapods and fish larvae, regional commercially important taxa, are being segregated from selected late-summer (July, August, September) samples, enzymatically digested, and inspected for microplastics content. The chemical identity of putative plastic particles is determined via Fourier Transformed Infrared Spectrometry.

Our ongoing research will provide a valuable baseline for future reports to compare against and will inform on the current state of microplastics pollution bioavailable to zooplankton in the central north-west area of the North Sea. Our project is directly informing Natural England's work, highlighting the need to set up standards and to include continuous microplastics pollution monitoring for the North Sea waters in British and European legislation. Furthermore, we propose the use of the existing harmonised zooplankton monitoring programmes worldwide, and where deemed necessary, the creation of new ones, for the continuous assessment of bioavailable microplastics pollution to inform appropriate policy decisions at local, national, and international levels.

About the author

Dr Priscilla Carrillo-Barragán is a Research Associate working with PIs Dr Heather Sugden and Dr Clare Fitzsimmons at the Dove Marine Laboratory, Newcastle University, UK. More information about their work is available here.