© José Escaño Mooring scar posidonia

The Challenge

Algae and seagrass communities are essential for the well-being of coastal communities, offering clear waters full of life, essential for sustainable tourism.

They are also key habitats to replenish fisheries, acting as carbon sinks and as a protective barrier against the effects of climate change such as coastal erosion caused by storms.

Unfortunately, they are at serious risk of degradation caused by human activity.


Many seagrass and seaweed species are what we call habitat-forming species; i.e. those that create a habitat, providing resources which were previously limited or non-existent, such as food or shelter.

In addition to creating this habitat that can be used for many other species, many also provide essential services to coastal communities like maintaining attractive landscapes for touristic activities, replenishing fish stocks or protecting the coast against the increasing erosion caused by climate change.

The loss of marine plants due to human activities is one of the most urgent problems in nature conservation worldwide:

  • Of the approximately 177,000 km2 of seagrass that exist throughout the world, it is estimated that between 7 and 19% of its current surface (about 33,000 km2) has been lost; that is the equivalent of the area of more than 4 million football fields. Only in the Mediterranean, it is estimated that 446 km2 (more than 62 thousand football fields) have been lost.
  • Many seaweed forests of the genus Cystoseira have severely declined in recent decades. There are 47 species of Cystoseira in the world, and the Mediterranean host 32 of them, almost 50% of which are endemic (they only exist here). In the Balearic Islands there is still a great diversity of these species, which have already disappeared from many coastal areas of the Mediterranean basin. Unlike other seaweed species, Cystoseira reproduce only locally, and cannot colonize distant areas on their own. Therefore, to recover these forests in the areas where they have disappeared, it is necessary to carry out reforestation actions.

Furthermore, the species that thrive in shallow water areas are the most affected because they are in a borderline environment, exposed to impacts of both land and marine origin. This situation is especially serious in the Mediterranean; despite being one of the seas that harbours the highest biodiversity in the world, it is also one of the most threatened by human activities. This is mainly due to the fact that there is little exchange of water with the ocean (it is a semi-closed sea), its coasts are highly inhabited and there is a huge maritime traffic.

© José Escaño janina posi flare

The solution

Algae and seagrass communities are transplanted or reinforced in small plots of shallow coastal seabed.

These spaces become social and environmental laboratories where citizens and science converge, building the marine capabilities of the people and enabling their participation in citizen science.

When underwater forests regenerate, they create new habitats where other species of animals and plants can thrive, contributing to the regeneration of biodiversity and thereby optimising productivity in terms of benefits for society.


Regeneration: The act of improving a place or system, especially by making it more active or successfull.

The United Nations decade for Ocean Science for Sustainable Development starts in 2021. Much more needs to be done if we are to reverse the loss of health of the marine ecosystems, so we can together create suitable conditions for a truly sustainable development of the oceans, seas & coasts.

Traditionally, environmental restoration comprised simple actions aimed at returning a site’s ecosystem functions or species composition back to a historic state. In contrast, modern restoration strategies embrace both social and ecological considerations and are guided by multiple goals including not only environmental ones, but also those that speak to human well-being (e.g. alleviating poverty).

Within this context and trend emerges MedGardens in the Balearic Islands. Successful and innovative restoration techniques for seagrass and seaweed will be carried out in small plots located in shallow areas, accessible to sea users.

Community will play a fundamental role in the entire restoration process through the co-management of each MedGarden, together with the scientific community and the local administrations.

MedGardens offers a chance for everyone to fix what we’ve broken, and the hope that we can.



NIF G02795341
Francesc Vidal i Sureda 71
07015 Palma de Mallorca