Site details

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Flag of Portugal
5 stars - Fully protected as a national park or Natura 2000 site by national legislation
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Aerial view of the Ria Formosa. Photo: M Sprung

Synoptic description of site:

A mesotidal lagoon extending for about 55 km on the south coast of Portugal

Extensive description of site:

The Ria Formosa is a mesotidal fully marine coastal lagoon, extending for about 55 km on the Algarve coast, South Portugal. Most of the lagoon is shallow and consists of saltmarshes and tidal flats. There is an intense water exchange via 7 inlets through the dune belt by which the lagoon is separated from the Atlantic Ocean. The rocky habitats are artificial.

Habitats present:
Seagrass bedsX

Description of fauna and flora:

The fauna and flora have been under investigation for several decades, with an increased intensity since the 1980s.

Pristiness: Moderate


Despite 3 towns on its border, there is no major industrial activity or major harbours; only small scale fishing activity in the lagoon; no permanent rivers drain into the system

Human impact:

There is no heavy industry, but three major towns are situated around the lagoon amounting to a population of about 220,000, with some tourist centres at its extreme points. In many parts of the lagoon bivalves are cultivated (mainly Ruditapes), and some aquaculture enterprises have been established in abandoned salinas.


Facilities for marine biodiversity research are available, from small boats to fully equipped laboratories and field stations, and a University Library.

Available database and website:

There are no websites at present for biodiversity data, but some dozen publications, reports and theses on biodiversity related subjects.


Commitment and ongoing research:

Several institutions around the Ria Fomosa are involved in research activities: the Instituto da Conservação da Natureza (ICN; part of which is responsible for the administration of the Natural Park Ria Fomosa), the Instituto de Investigação das Pescas e do Mar (IPIMAR, particularly on species of economic interest), the Universidade do Algarve with its research centre Centro de Ciências do Mar on aspects of biodiversity from documentation of the distribution of species to molecular biological methods.