Higher than expected levels of microplastics were found across the sea off Abu Dhabi, a new study has found.
When Environment Agency – Abu Dhabi and UAE University researchers tested seawater and sediments at dozens of locations, including near offshore islands that see little human activity, all were found to contain microplastics, which may include fibres from materials and tiny fragments from the breakdown of larger plastics.
Thies Thiemann, a professor of chemistry formerly at UAE University in Al Ain and one of the study’s authors, said that the levels of microplastics were “definitely higher” than expected. Their presence is seen as particularly concerning because of the challenges involved in removing them.
“Once they’re in the marine environment, it’s hugely difficult to get them out. It’s like a legacy that we will provide for the future generations. That’s how it is, unfortunately,” Prof Thiemann said.
The team behind the study in Frontiers in Marine Science say it is the first comprehensive analysis of microplastic levels across Abu Dhabi waters. Samples were taken at 46 sites, with surface water, water below the surface (subsurface water) and sediment looked at.
The highest microplastic levels in water were found near oilfields, where the average was 9.3 particles per litre across surface and subsurface samples.
Offshore islands had the second-highest concentrations, at 8.8 particles per litre. In the study, the scientists said that it was “especially worrying” that significant concentrations of microplastics were found off Jarnain Island, which is around 50km north of the coast, and Bu Tinah Island, a rarely visited location about 40km from the coast.
Currents affairs
Surface currents, which run anti-clockwise in the Arabian Gulf, may have brought microplastics towards the islands from other locations.
“The role of surface currents in the Arabian Gulf in carrying microplastics from more northern parts of the Gulf should be studied further. Many of the islands are subject to the influence of these marine currents,” the scientists wrote.
Prof Thiemann said that other natural habitats closer to the city may be more influenced by local discharges.
Natural marine habitats further from industrial facilities had some of the lowest concentrations, at around 4.5 particles per litre of water. At public beaches, concentration averaged 6.7 particles.
Sampling took place between April and July 2024, and severe weather before this, including a rare hailstorm earlier in the year, could have caused damage that resulted in the release of microplastics, Prof Thiemann said. Also, extreme rains affected the UAE in April 2024. These events may have affected some readings.
The study focused on microplastics 0.3mm to 5mm in size, with the researchers characterising nearly 1,500 particles by size, shape and colour.
Microplastic concentrations have varied widely in other studies. A 2018 analysis found concentrations between 2.06 to 13.51 pieces per litre at depths below 6,000 metres in the Mariana Trench in the Pacific Ocean, figures that were “several times higher” than just below the surface.
Concentrations as high as 12,000 particles per litre have been detected in Arctic sea ice.
A December 2025 study in the Marine Pollution Bulletin journal forecast that in 2100, average microplastic concentrations globally would be 9.7 times what they were in 2008.
Harmful impact
Microplastics can harm marine organisms, according to Prof Richard Thompson, who researches microplastics in the marine environment at the University of Plymouth in the UK.
“The larger particles that sit in the gut can cause blockages and lead to, effectively, starvation, reducing growth and fecundity [the potential to reproduce],” he said.
Smaller particles can, he said, pass from the gut to the circulatory system of marine creatures and in that way be transported around the body.
In marine molluscs they accumulate in the hepatopancreas, a digestive gland. Hormone disruption from microplastics has also been demonstrated in marine organisms, Prof Thompson said.
Prof Thiemann said that microplastics in the marine environment could find their way into people when they ate fish and shellfish, including if it was cultivated.
Prof John Burt, a marine biologist at NYU Abu Dhabi, said that as large-scale removal of microplastics was not practical, efforts should be made to stop further inputs where they originated and to capture particles before they reached the sea.
“Research is needed on what the primary sources are in the Arabian region, as these can be quite varied, from wastewater treatment facilities (generally a major source), to industrial or stormwater effluents, and even plastic litter that makes it to the sea,” he said.
Beach clean-ups, and litter-picks in other locations, are held in many emirates, and Prof Burt said that these could remove larger plastic items before they fragmented into microplastics.
“In other words, clean-ups are useful, but mainly as prevention rather than as a solution,” he said.
Prof Thiemann praised beach clean-ups as being “a good idea” and said that in his native Germany, young children were particularly enthusiastic about taking part.
“Relatively young children, primary schoolchildren, I think that’s where education is needed, at that level,” he added.
As well as helping with beach clean-ups, there are other things that the public can do to reduce the flow of plastics into natural habitats.
“Textiles are often made not from natural fibres, but from various plastics, and when we wash these, the microfibres break down and end up eventually being discharged into the environment from water treatment plants as microplastics,” Prof Burt said.
Another concern is that some face creams or body washes contain small plastic beads, which end up in the water system.
“So, people can make choices about the products they are buying, and also avoid single-use plastics or unnecessary plastic wrapping of foods,” he said.
