Restoration of Neptune seagrass meadows affected by mooring systems

Neptune seagrass meadows are the “underwater forests” of the Mediterranean. Neptune seagrass (Posidonia oceanica) is an endemic Mediterranean marine phanerogam that forms vast meadows, ranging anywhere from the surface to more than 40 meters below water.

Although they are nationally and internationally protected, Neptune seagrass meadows are suffering a critical regression.

Boat mooring is one of the main causes behind this regression. To reduce this impact, conservation actions generally consist of creating mooring fields, where buoys are attached to the seabed, normally with concrete blocks. These mooring systems are often not installed correctly, severely affecting Neptune seagrass and other species. This has an even greater impact than mooring itself.


Since 2018, the project’s objective has been to restore the Neptune seagrass meadows in mooring buoy fields in certain important natural parks, such as Montgrí, Illes Medas and Baix Ter and Cap de Creus.

The project is two-phase:

Firstly, a diagnosis is conducted in the mooring fields with the concrete blocks affecting the Neptune seagrass. These blocks are GPS positioned, and an evaluation on relocating or removing them is conducted in order to ascertain how to take action.

The second phase consists of repositioning or removing the blocks to guarantee the health of the Neptune seagrass meadows.

Throughout 2018, 10 mooring fields were diagnosed (with a total surface area of 52 hectares) and 452 concrete blocks affecting Neptune seagrass.

Actions were carried out in the municipalities of Torroella de Montgrí (Natural Park of Montgrí, Islas Medas and Baix Ter), Rosas and Cadaqués (Cap de Creus Natural Park).

Initially, 15 blocks were transferred and a total of 139 were removed and sent to a controlled dump as waste. Moreover, a total of 47 other remains were extracted from the concrete blocks, which were also affecting the Neptune seagrass.

Our team is currently planning a second phase to remove the remaining concrete blocks.

This project is carried out for the Autonomous Government of Catalonia.

“The regression of Neptune seagrass throughout the entire Mediterranean is a fact… Over the past 50 years, estimates state that the surface area occupied by Neptune seagrass has fallen by over 30% in the western Mediterranean.”