Separating microplastics. | Marilles Foundation


Engaging citizens in the collection of data which is later validated by professional specialists is an essential activity that will help us achieve properly conserved seas and coasts. Citizens’ science is a very cost-effective way to collect essential information that helps improve the management of our marine and coastal habitats, while at the same time it is a great way to engage members of the public who want to help with marine conservation but do not know where to start. Divers, students, tourists, professional and recreational fishermen, sailors or just anyone taking a stroll by the sea can take part in one of several projects available from the Observadores del Mar platform:

Observadores del Mar is the largest citizens’ science platform in Spain mediating between citizen scientists and professional researchers. It has been in action since 2012, organising the collection of data all around Spain, and the Balearics have played a key role in its development.

Microplastic Watchers is one of the projects available from Observadores del Mar. It aims to collect data of the presence and abundance of very tiny (micro) and not so tiny (meso) plastics in the sea, which helps scientists better diagnose the problem and raise awareness of this global issue. Participants compile data monthly on specific beaches, following a scientific protocol of sampling and classifying plastics of different types and sizes. All data is subsequently validated by research institutions and made publicly available.

Schoolchildren turn into scientists through Microplastic Watchers

Microplastic Watchers has secured the participation of 38 secondary schools and 9 primary schools, with a total of 3,126 students monitoring 23 beaches in Barcelona, Girona, Tarragona and the Balearics. Since 2017, the marine conservation organisation GEN-GOB has coordinated the project in Ibiza and Formentera, carrying out regular visits to 5 beaches and working with several schools and youth clubs across the islands.

This week, GEN-GOB’s sister organisations GOB Minorca and GOB Majorca have joined the initiative, enlarging the sampling potential across all the Balearic Islands. Throughout 2021 they will work with3 schools: CEIP S’Hort des Fassers in Alcúdia, Majorca; and Margalida Florit and Mestre Duran in Minorca. Boys and girls will monitor what is happening within the beaches of Son Bou, Algaiarens and the Alcudia beach, providing monthly sampling and analysis of the sand from each of these beaches.

The incorporation of the analysis of these beaches will supply new comparative data in relation to the accumulation of microplastics on the beaches of all the islands. It will enable us to answer key questions such as whether there are variations in the concentration of micro and mesoplastics between beaches and islands, what type of plastic accumulates most, or, whether changes occur at different times of the year.

Students do not only contribute to the research, they also learn and experience science as a real, living process. The project also creates a social conscience and an awareness of the global issue of plastics and how these affect the marine environment of the Balearics.


Since 2018 the Marilles Foundation has established a strategic collaboration with Observadores del Mar to strengthen marine citizens science projects in the Balearic Islands. In spite of the economic challenges that Covid has brought to the islands, last year an additional 11 entities, including diving centres, nautical clubs and non-profit organisations joined this initiative. There is much demand and we hope to add many more in 2021.

Observadores del Mar currently offers 15 projects. From micro plastics and invasive species, to seaweeds and seahorses. It plays an essential role in bringing people together and promoting a dialogue between society and scientists about environmental and conservation sea-related issues. The Balearics are becoming one of the most active regions in marine citizens science at the national Spanish level. Observadores del Mar are working to replicate lessons learnt here across Spain through their participation in the LIFE INTEMARES project led by Fundacion Biodiversidad, part of the Ministry for Ecological Transition and Demographic Challenge.