SUNCE said that every tourist season brings a large number of boaters, and that the growing number of vessels puts increasing pressure on the sea and coast, ranging from heavier maritime traffic and pollution to less visible impacts such as underwater noise and the destruction of Posidonia, a strictly protected seagrass species that provides a key habitat for numerous marine organisms.
The monitoring, conducted in 2023 and 2025 as part of the Interreg BIOPRESSADRIA project, covered Kornati National Park, the Pakleni otoci islands and Natura 2000 sites in Dubrovnik-Neretva County, where Posidonia seagrass meadows are a target habitat for conservation. Depending on the location, 25 to 65 percent of vessels were found anchored over Posidonia meadows. The share was lower in more heavily protected areas with established eco-moorings, such as Kornati, and higher around the Pakleni otoci islands and Badija.
SUNCE warned that conventional mooring systems, typically consisting of a concrete or stone block, chain, rope and surface buoy, can severely damage the seabed. Heavy blocks smother organisms beneath them, while chains dragged across the seabed create bare areas around moorings. Because Posidonia grows back extremely slowly, damaged areas can take decades to recover.
The group advocates eco-moorings as a more sustainable alternative. These use a geotechnical anchor, a raised seabed line and an elastic mooring line instead of a heavy block and chain, limiting contact with the seabed to the point where the anchor is installed.
SUNCE said modern mooring systems can reduce the area required for a mooring field by up to 40 percent and can be adapted to different seabed types. It stressed, however, that eco-moorings require careful planning, appropriate anchoring systems, professional installation and regular maintenance.
The group said eco-moorings should be accompanied by restrictions on anchoring over Posidonia meadows, effective monitoring at sea and education for all users in order to protect the habitat.