Saint-Tropez Biohut

UPDATE FEBRUARY 2026

Around fifty artificial nurseries dedicated to preserving post-larvae fish have been installed in the port of Saint-Tropez. These ‘Biohut©’ aim to restore the ecosystem service of nurseries by protecting these post-larvae and young recruits from predation.

Since 2021, Ecocean has been running awareness campaigns for the general public, workshops for schoolchildren and monitoring of the ‘Biohut©’. A report published twice a year examines the effectiveness of this process as well as biodiversity trends in the port of Saint-Tropez.

Divers record the species that have developed and their distribution within the port area, confirming the value and benefits of this initiative, which is perfectly in line with the eco-responsible approach adopted by the municipality of Saint-Tropez and its port for several years now.

2024 REPORT

The Biohut© project has led to a significant increase in biodiversity in the port of Saint-Tropez. The results show a clear improvement in the population of juvenile fish and vagile fauna:

• 503 juveniles recorded in 3 years, representing 25 species.
• Threefold increase in average fish abundance (from 5.4 to 15 individuals per 10 linear metres).
• Specific richness doubled, from 8 to 15.3 species observed
• Species observed: various types of sars, capon, pageot, black and purple sea urchins, scallops, black scallops.

Monitoring of vagile fauna (invertebrates and cryptobenthic fish):

• 529 individuals recorded belonging to 39 species.
• Notable species: sea urchins, scallops, black scallops.

2024 STUDY

2023 STUDY

2022 STUDY

Biohut© nurseries are cages made from recycled materials that are installed on quays or sea walls close to the water’s surface. These cages therefore serve as habitats for the youngest fish (post-larvae and young recruits), providing them with a ‘refuge’ from predators.

Biohut© can also shelter other species such as molluscs, crustaceans and echinoderms.

Biohut© are monitored and a report is produced twice a year to study their effectiveness and the movement of biodiversity in the port.

The town of Saint-Tropez and the harbour master’s office invest each year to make Saint-Tropez an eco-responsible city. Each project is a further step towards inviting boaters, residents and visitors to join us in this initiative.

Ecocean often introduces nurseries to children during activities for primary school classes in Sainte-Anne and Les Lauriers de Saint-Tropez through fun games to raise children’s awareness of marine ecology.

© Rémy Dubas