title: Unexpected abundance and long-term relative stability of the brown alga Cystoseira amentacea, hitherto regarded as a threatened species, in the north-western Mediterranean Sea.
abstract: Cystoseira amentacea is a Mediterranean endemic alga thriving on very shallow rocky substrates. It has been considered as a threatened species, having experienced a steady decline and is therefore protected by international conventions. The historical distribution of the species has been assessed along the French Mediterranean coast, on the basis of 467 articles and herbarium vouchers. We have produced an accurate map of its current distribution and abundance along 1832 km of coastline, through in situ surveys. C. amentacea was observed along 1125 km of shoreline, including 33% of almost continuous or continuous belt. In most of its range, there is no evidence of loss, except in 4 areas of Provence, French Riviera and Corsica. A significant relation was found between the absence or low abundance of C. amentacea and the vicinity of ports and large sewage outfalls. The status of conservation of the species should therefore be reassessed.
authors.affiliation: Aix-Marseille University, and Toulon University, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus of Luminy, 13288 Marseille cedex 9, France. Electronic address: thierry.thibaut@univ-amu.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Thibaut
authors.affiliation: Aix-Marseille University, and Toulon University, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus of Luminy, 13288 Marseille cedex 9, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Blanfuné
authors.affiliation: European Commission, Directorate-General for Maritime Affairs and Fisheries, Avenue Joseph-II, 79 office 02/67, 1049 Brussels, Belgium.
authors.forename: Laurent
authors.initials: L
authors.lastname: Markovic
authors.affiliation: Aix-Marseille University, and Toulon University, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus of Luminy, 13288 Marseille cedex 9, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Verlaque
authors.affiliation: Aix-Marseille University, and Toulon University, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus of Luminy, 13288 Marseille cedex 9, France.
authors.forename: Charles F
authors.initials: CF
authors.lastname: Boudouresque
authors.affiliation: Aix-Marseille University, and Toulon University, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus of Luminy, 13288 Marseille cedex 9, France.
authors.forename: Michèle
authors.initials: M
authors.lastname: Perret-Boudouresque
authors.affiliation: Institut za Biologiju Mora, Rukovodilac laboratorije, Naučni saradnik, P.Fah 69, 85330 Kotor, Montenegro.
authors.forename: Vesna
authors.initials: V
authors.lastname: Maćic
authors.affiliation: Université Nice-Sophia-Antipolis, EA 4228 ECOMERS, Faculté des Sciences, Parc Valrose, 06108 Nice cedex 2, France.
authors.forename: Lorraine
authors.initials: L
authors.lastname: Bottin
mesh_terms: D000818:Animals; D017756:Aquaculture; D056727:Endangered Species / Q000266:history*; D005602:France; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D008522:Mediterranean Sea; D000459:Phaeophyceae; D012722:Sewage / Q000009:adverse effects; D014876:Water Pollution / Q000009:adverse effects
chemical_list: D012722:Sewage
keywords: Conservation status; Cystoseira amentacea; Human pressure; Long-term study; Mapping; Mediterranean Sea