Plastic pollution on the seafloor has an irreversible impact on marine ecosystems and can seriously affect the health and behavior of wildlife. Such waste transforms seafloor habitats that are rich in flora and fauna into marine landfills, where plastics accumulate yet can go unnoticed because they are not visible from shore. This problem can be particularly pronounced in places where large quantities of single-use plastics are used and discarded close to the sea, such as in coastal locations that are popular with tourists. As part of a global project to investigate the extent of seabed plastics in biodiverse sites with high levels of tourism, Oceana scientists and divers surveyed a dozen different habitat types (including corals, sandy bottoms, and algal forests) along the coast of Valencia, and in six marine habitats on the island of Mallorca. The underwater surveys were conducted outside the tourist season and, in the case of Valencia, during the Covid-19 pandemic. Despite this, we nevertheless found large quantities of plastic waste in every habitat type documented. The most frequently observed items were single-use plastics, such as bags, food wrappers, packaging, cutlery, and drinking containers, as well as abandoned fishing gear. Healthcare items, such as disposable masks and gloves, were also observed, in addition to other types of garbage. Wildlife, including several threatened species, was filmed in plastic-polluted areas, at risk of ingesting plastic fragments, growing upon them, or entangled in plastic debris. In other cases, species were settled on moving plastic pieces that can be transported outside their habitats. Overall, our findings demonstrate that the excessive use of plastics is directly impacting delicate underwater habitats and the species that live in them. Our results add urgency to the need for plastic-free coastal regions, restaurants, and tourist resorts, and for significant reductions in the production of single-use plastics (SUPs).

Funding Acknowledgement: LIFE19 NGO/FPA/ES/000004 – Fundación Oceana