Overview

• Neptune balls are compacted fibers of the Mediterranean seagrass Posidonia oceanica that form as shed leaves roll in waves and often wash ashore.
• The University of Barcelona team, led by Anna Sànchez-Vidal, found nearly 1,500 plastic fragments per kilogram in tightly bundled seaballs sampled on Mallorca beaches in 2018–2019, reporting the results in Scientific Reports.
• Extrapolating across Mediterranean seagrass production, the researchers estimated up to about 867 million plastic items could be transported out of coastal waters each year.
• Debris captured ranges from microplastics and food packaging to twine, bottle caps and sanitary items, with many pieces physically locked into the fibrous structure.
• Scientists stress this is not a solution to marine litter, since many bundles do not reach shore and seagrass meadows have been shrinking for decades.