Ibiza is facing renewed concern over the protection of its Posidonia oceanica seagrass meadows, after new figures revealed thousands of boats were detected anchoring illegally over the protected habitat in 2025.
According to data analysed by Ibiza & Formentera Preservation, 4,813 vessels were detected anchored over Posidonia in the waters of Ibiza and Formentera last year. The organisation is now calling for stronger surveillance and enforcement as pressure on the marine ecosystem continues.
Ibiza Sees a Sharp Increase
Ibiza accounts for the most concerning increase.
In 2025, the Posidonia Surveillance Service required 3,468 boats to move because they were anchored over Posidonia in Ibiza, compared with 1,719 in 2024 — effectively doubling in one year.
The increase does not necessarily mean that the number of boats across the entire island doubled. The Sustainability Observatory says part of the rise was linked to surveillance being extended into new high-traffic areas, where more illegal anchoring was detected.
Nevertheless, the scale of the problem is significant. The vessels moved represented 21.3% of those checked in Ibiza, the highest proportion recorded among the Balearic Islands.
Only 18 Formal Infringement Proceedings
One of the most striking figures concerns enforcement.
Despite 4,813 boats being detected over Posidonia in Ibiza and Formentera, only 18 formal infringement proceedings were opened in 2025 — 15 in Ibiza and three in Formentera.
That represents approximately 0.37% of the detected vessels, or just one formal case for every 270 boats identified.
Ibiza & Formentera Preservation says the figures demonstrate the need for more environmental officers and additional resources for the Posidonia Surveillance Service.
Why Posidonia Matters
Posidonia oceanica is a Mediterranean seagrass that forms extensive underwater meadows and is protected under European, Spanish and Balearic environmental legislation.
These meadows are fundamental to the health of the Mediterranean marine environment. They provide habitat for marine species, contribute to water quality and help stabilise coastal ecosystems.
Anchors and their chains can physically damage the plants and disturb the seabed. Repeated anchoring in the same areas can therefore place considerable pressure on these slow-growing ecosystems.
For an island such as Ibiza, where recreational boating increases dramatically during the summer, protecting these underwater habitats is particularly important.
More Boats, More Pressure
The latest figures come as recreational boating continues to place increasing pressure on Balearic coastal waters during the peak tourism season.
Ibiza's surveillance service operated with four boats in 2025, part of a fleet of 19 vessels covering the Balearic Islands. The Ibiza units carried out 20,528 actions, including information campaigns, advice and checks on anchor and chain positions.
However, total activity in Ibiza actually fell by 8.8% compared with the previous year, according to Ibiza & Formentera Preservation.
In Formentera, meanwhile, surveillance activity increased considerably, from 46,785 actions in 2024 to 61,400 in 2025.
The Balearics Are Seeing Improvement — But Ibiza Is Different
The situation in Ibiza stands out against the wider regional picture.
Across the Balearic Islands, the average rate of improper anchoring detected by the surveillance programme fell to 6.4% in 2025, one of the lowest levels since the monitoring service began. The highest regional rate was recorded in 2018, at 17.3%.
Ibiza, however, moved in the opposite direction, with the number of boats requiring relocation increasing from 1,719 to 3,468.
The contrast has raised questions about whether the island's current resources are sufficient to deal with the level of nautical activity during the summer.
Eco-Friendly Moorings Offer an Alternative
The Balearic authorities have also expanded the use of low-impact ecological mooring fields designed to reduce anchoring damage in sensitive marine areas.
In 2025, Ports IB managed eight such fields across the Balearics. Ibiza had one field with 39 mooring buoys, while Mallorca had 115 and Formentera 88.
These systems provide designated places for boats to moor without dropping anchors directly onto protected seagrass.
Protecting Ibiza's Sea
The latest figures underline a difficult challenge for Ibiza.
The island's popularity brings increasing numbers of boats into its waters, but the same marine environment that attracts visitors is also one of the island's most fragile natural assets.
For environmental organisations, the issue is no longer simply about informing boat owners where they can and cannot anchor. They are calling for stronger surveillance, more resources and more effective enforcement to ensure that repeated illegal anchoring does not continue damaging Posidonia meadows.
The message for boaters is straightforward: anchors should never be dropped over Posidonia. Choosing sandy areas or designated ecological moorings can help protect one of the Mediterranean's most important marine habitats.
