National survey finds microplastic pollution around Britain’s coastline could be double than previously recorded

The team, which included University of Surrey academic Hannah Davies, rowed over 2,000 miles in just 50 days as part of the GB Row Challenge 2024, whilst also collecting crucial data on microplastic pollution, underwater man-made sound, water temperature, salinity and biodiversity.  

Samples of seawater, collected around the coast of Great Britain, were analysed at labs at the University of Portsmouth and found to have an average concentration of 59 microplastic particles per cubic metre of seawater (59 MP/m³) – more than double the levels reported in comparable surveys conducted in 2022 and 2023, which recorded averages of 23 and 20 MP/m³ respectively. 

In some locations, concentrations were more than twice those previously measured, with the highest level – 418 MP/m³ – recorded in the Irish Sea, the greatest concentration observed across three years of monitoring. 

Hannah Davies, Senior Lecturer in Veterinary Clinical Practice from the University of Surrey, said:  

“Measuring microplastics is an extremely complex task. Environmental conditions such as sea state and sampling conditions may impact the detection of the pollutant, as rougher seas could mean the plastics, which could have already been there, are more thoroughly mixed with seawaters.  

 “Regardless of how long the microplastics have been in the sea, current levels are worrying and are detrimental to sea life.  Not only do they cause physical harm to marine animals, but they also contaminate seawaters, potentially impacting the safety of humans who use the waters for leisure and work activities.”  

 As well as collecting invaluable data, the team also secured a new Guinness World Record for the fastest time a mixed team has taken to row unsupported around Great Britain. 

 GB Row Challenge Founder, William de Laszlo, has completed the challenge twice, said: 

 “2024 was an exceptionally tough year for the crews from a weather perspective. They faced volatile weather fronts and unseasonable headwinds, yet both teams still collected invaluable empirical data that will contribute to ongoing ocean research. The wider GB Row Challenge team and our partners are extremely grateful for their determination and efforts.” 

The data from this race and previous races will be hosted on The Crown Estate’s Marine Data Exchange, one of the world’s largest collections of marine industry data and will be accessible to scientists worldwide. 

Notes to editors