To achieve our main objective, in Anèl·lides, serveis ambientals marins we participate in the following projects:

Posidònia activa: the importance of citizen science in unprotected areas

The Posidònia Activa citizen science project is being carried out on the seabed of the Catalan Coast, with the aim of mapping the seabed of unprotected areas to accurately locate and delimit the posidonia meadows, as well as studying the biodiversity associated with them. This will make it possible to locate on the map which areas are of the greatest biological importance, promoting new initiatives to avoid the reduction of these endemic ecosystems of the Mediterranean Sea.

Posidonia oceanica is an endemic marine phanerogam of the Mediterranean Sea with a great biological impact, since it’s a precursor of important marine ecosystems, it’s shelter and food of thousands of species, CO2 resrevoir, natural barrier that offers coastal protection against regression, favors the oxigenation of the sea, the maintenance of marine seabed and expels microplastics thnaks to the balls produced with the dry leaves. For these, and many other reasons, it is essential to preserve this species of phanerogam, currently in danger and with an advanced regression. This project began in 2020 with the mission of not leaving any marine space on the Catalan coast without sampling, to protect this sea grass, which provides us with almost 50% of the planet’s oxygen.

This study is carried out with volunteer divers and snorkelers, who help us to take the biological measures to observe the state of the prairies and to collect the necessary data that allow us to elaborate a map of marine species of the area and thus to study the most biologically important habitats of the studied municipalities.

Interactive map with the cartographies of Posidònia Activa

Download the cartographies of Posidònia Activa

Specific objectives

  • Promote experimentation and practical science among the youngest

  • Bring science closer to citizens and stimulate their participation in scientific processes and data collection

  • Deepen the observation and knowledge of Posidonia oceanica

  • Geolocating the meadows of non-protected areas, disseminating their mapping

  • Delimit the Posidònia meadows and carry out the annual monitoring of these

  • Identify and record all the species of living organisms in the studied areas

Phases and activities

  • In 2020 the project started in the relevant area in Creixell and Roda de Berà, locating and studying an 80-hectare prairie.
  • In 2021 the study was carried out in the municipalities of Coma-ruga and San Salvador, delimiting 6 areas of Posidonia oceanica, the largest of them of 11 hectares.
  • In 2022, the area corresponding to Calafell was studied, which houses large prairies from Cymodocea nodosa and a meadow in regression from Posidonia oceanica, which is why in 2023 the pilot phase of transplantation in the municipality of Calafell was started.
  • In 2023, the study area was Cunit and Cubelles, next to Calafell. There two meadows were located, the biggest one with a size of 4 hectares.

The project aims to cover a new area of the Catalan Coast each year, as well as to carry out annual monitoring of all the prairies already mapped in the previous phases of POSIDÒNIA ACTIVA.

This project is led by:

With the scientific collaboration of:

With the funding of:


Catalan Coast


Soon we will announce the dates of the dives, the snorkel activities and the dissemination activities


The target audience of the project:
Divers with Advanced certificate and more than 10 dives
Snorkelers with good swimming ability

General public:
Training sessions
Informative workshops

Functional diversity public:
Posidonia sensory workshop


Citizen science project

How to take part?

Send an email to  with Posidonia Activa as the concept