Site details

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5 stars - Fully protected as a national park or Natura 2000 site by national legislation
LTBR Focal Site

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Trémies Cave, dark zone, with highly diverse fauna of encrusting invertebrates. Photo: Harmelin, Jean-Georges

Synoptic description of site:

Uninhabited and uneven shoreline, indented by deep fjords, including numerous submarine caves. A limited part (Cortiou) under the influence of the sewage outlet of Marseille (physico-chemical treatment, but biological one planned).

Extensive description of site:

The uninhabited and uneven limestone shoreline 15 km long, indented by deep “calanques” (fjords), includes numerous fully submerged submarine caves.

Habitats present:
Littoral XX
Seagrass bedsX

Description of fauna and flora:

The site contains a representative array of the Mediterranean habitat types, including rocky substrata, caves and Posidonia meadows. It is rich in flagship species, such as the red coral Corallium rubrum, gorgonians and numerous endemic Mediterranean species.

Human impact:

A limited part (west side) is under the influence of the sewage outlet of Marseille, which is treated by physico-chemical methods (biological treatment is planned). The eastern area is relatively free from pollution. The site is popular among divers and pleasure boats. It has a limited legal protection, with a planned National Park. Natura 2000 habitat.


Facilities are available at the Centre d’Océanologie de Marseille (COM), with easy access from Marseille and Cassis harbors.

Available database and website:

The species inventory for several invertebrate groups (sponges, serpulid polychaetes, bryozoans, crustaceans) and algae is available in the COM.

Commitment and ongoing research:

The site has been intensively studied by the COM for more than 40 years, both in the zone under the influence of the Marseille sewage and in the unaffected zone. The studies include monitoring and inventories of the sublittoral rocky shore, coralligenous and cave fauna, monitoring of the evolution of the soft bottom fauna and bioaccumulation research in invertebrates.

Additional Information:

Examples of references available: Ledoyer, M. 1989. Les Mysidacés (Crustacea) des grottes sous-marines obscures de Méditerranée nord-occidentale et du proche Atlantique (Portugal et Madère). Marine Nature 2: 39-62. Logan, A. & H. Zibrowius 1994. A new genus and species of rhynchonellid (Brachiopoda, Recent) from submarine caves in the Mediterranean Sea. PSZN.I: Mar. Ecol. 15: 77-88. Monniot, C. & H. Zibrowius 1999. Une ascidie du genre _Rhodosoma_ (Phlebobranchia, Corellidae) en forme de "boîte à clapet" redécouverte dans des grottes de Méditerranée. Zoosystema 21(3): 547-555. Pouliquen, L. 1971. Les spongiaires des grottes sous marines de la région de Marseille: écologie et systématique. Téthys 3(4): 717-758.