title: Correlation between pollution and decline of ScleractinianCladocora caespitosa(Linnaeus, 1758) in the Gulf of Gabes.
abstract: During an expedition in 2014 in the Gulf of Gabes that aimed to evaluate the impact of the pollution of the phosphate industry on the marine environment, numerous dead coral fragments were retrieved from several stations along a 18 km long transect in front of the industry complex of Gabes. Detailed taxonomy of these coral fragments shows clearly that all fragments belong to the speciesCladocora caespitosa(Linnaeus, 1758). Quantitative analysis of the coral fragments indicates a positive correlation with stations characterized by positive bathymetric anomalies. We suggest the presence of probable small-scaled (up to 4 m high) biogenic (palaeo-) build-ups composed mainly of coral colonies and bryozoans. Radiocarbon dating of three coral fragments show ages as old as 1897, 1985 and 1986 AD and suggests the presence of livingC. caespitosaas close as 6 km to the phosphate treatment industry of Gabes at least until 1986 AD. This latter age coincides with the construction of the ammonium phosphate production plant, in 1979, in the Gulf of Gabes with an increase of the natural phosphate production. The higher impact of pollution on the marine environment in the inner part of the Gulf of Gabes likely induced the decline ofC. caespitosa. This is well in agreement with enhanced siltation processes suggested by the sedimentary facies and grain-size analyses presently characterizing the Gulf of Gabes nowadays.
authors.affiliation: Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700 Fribourg, Switzerland.
authors.forename: Akram
authors.initials: A
authors.lastname: El Kateb
authors.affiliation: Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700 Fribourg, Switzerland.
authors.forename: Claudio
authors.initials: C
authors.lastname: Stalder
authors.affiliation: Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700 Fribourg, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Neururer
authors.affiliation: Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700 Fribourg, Switzerland.
authors.forename: Chiara
authors.initials: C
authors.lastname: Pisapia
authors.affiliation: Department of Geosciences, University of Fribourg, Chemin du Musée 6, 1700 Fribourg, Switzerland.
authors.forename: Silvia
authors.initials: S
authors.lastname: Spezzaferri
keywords: Ecology; Geochemistry