A study reveals the presence of waste materials in the Balearic Islands ocean floor

IbizaPreservation, Mallorca Preservation and Menorca Preservation, are together leading a new Project focusd on the identification and análisis of the waste foundin the Balearic Islands seabed. The study takes part of a common marine conservation initiative “Tejiendo Futuro, Alianza para la Preservación de Baleares”, and relies on the scientific evidence provided by the Spanish Institute of Oceanography (IEO).

During the first phase, the project enabled the realisation of submarine sampling in 20 different balearic stations, six of the distributed between Ibiza and Formentera, thanks to the collaboration of various diving centres and a total of 60 recreational diving volunteers in the four islands, 42 of them in Pitiusas. The Pitiusas stations have been chosen to represent different types of environments: areas located within marine reserves influenced by urban environments, zones in pristine natural spaces, and urban enclaves with strong human impact have been studied. In addition, all four cardinal points —north, south, east, and west— have been covered to obtain a representative overview of the sublittoral zone, that is, the part of the coastal marine area that is always underwater, from the lower limit of the tides to the depth where algae no longer grow, the organizations explain.

On their behalf, Mallorca Preservation and Menorca Preservation have developed samplings in 7 different stations each, using a common methodology. The main objective of the project is to obtain comparable and consistent data that allow to analize the marine waste distribution and typology in shallow Waters thus advancing the understanding of human impact on the coastal environment.

“The underwater strip comprehended between 0 and 10 meters deep remains understudied in terms of plastic waste impact, despite being a highly sensitive area,” explains Elisa Langley, lead researcher for the study in Ibiza and coordinator of the Sustainability Observatory at IbizaPreservation. She emphasizes that “through this methodology, the aim is to fill an information gap that is crucial for improving waste management and designing awareness-raising actions in the marine environment.”

Each participating dive center conducts two dives per season with groups of volunteer recreational divers, following a standardized protocol validated by the Spanish Institute of Oceanography (IEO). “The goal is to gather enough scientific data and images to produce a technical report that can support decision-making and raise public awareness,” explains Elisa Langley. The detailed classification of collected waste will allow for a deeper analysis of the types of pollution affecting the Balearic coastline. “In addition to removing waste during the dives, the data collected will help us better understand the issue and contribute to Mediterranean-scale research,” she adds.

In Ibiza, the collaborating dive centers included Subfari (Portinatx, north), Anfibios (Sa Xanga, in the Ses Salines Natural Park, south), Aquadiving (Cala Martina, east), and Arenal Diving (S’Estanyol, Portmany Bay, west). In Formentera, the sampling was carried out with Formentera Divers in Es Pujols (Punta Prima, east) and Espalmador Bay (marine reserve, west).

Each site involved 8 volunteers per dive outing, who carried out dives in defined sampling areas (100 m² per pair), recording location, depth, seabed type, and environmental conditions. After collecting samples, teams also conducted cleanup operations in surrounding areas. “Once the sampling was completed, we performed a sweep of the area, collecting additional waste—outside of the scientifically defined zone—to leave the location better than we found it and to make the most of the equipment and dive in support of marine ecosystems,” Langley explains.

Among the items found were wet wipes, plastic wrappers, cups, sunglasses, yogurt bottles, jerrycans, pipe fragments, nautical ropes, bags, boat wood, a raffia sack, a toilet, and even an anchor—the last two being too heavy to remove at the time. “When we find large debris, the teams record its exact location so it can be removed later with proper equipment,” concludes the coordinator of the IbizaPreservation Sustainability Observatory.

Entities from Ibiza and Formentera, Mallorca, and Menorca emphasize that this joint action not only helps remove waste from the marine environment but also “advances a more accurate understanding of human impact on coastal ecosystems while fostering citizen engagement through participatory science.”

"Weaving the Future: an Alliance for the Preservation of the Balearic Islands" is a project led by IbizaPreservation, Mallorca Preservation, and Menorca Preservation, focused on tackling plastic pollution in the Balearic Islands through three lines of action: scientific research, promotion of a circular economy, and citizen awareness. The year-long initiative is funded by Depeche Mode and Swiss watch brand Hublot, channeled through Conservation Collective, the global network of foundations to which the three entities belong.