title: Response of a seagrass fish assemblage to improved wastewater treatment.
abstract: We compared the structure of a seagrass fish assemblage near a sewage outlet before and after improvements to wastewater treatment. To determine whether responses by the fish assemblage were due to changes in water quality or to other factors, comparisons were made with the structure of a fish assemblage from a nearby site unaffected by sewage effluent. Total species richness, density and biomass of fish, decreased at both sites over the 30-year period. An increase in mean trophic level near the sewage outlet following improvements in water quality indicated that wastewater treatment had another important effect. This result is consistent with the reductions in food webs supporting pelagic and benthic fishes that typically accompany decreases in nutrient inputs. Although improvements to wastewater treatment explained much of the variation in the structure of the fish assemblage at PC, our results also suggest that fishing and climate change, at both sites.
authors.affiliation: Mediterranean Institute of Oceanography (MIO), Aix-Marseille Université, CNRS, Toulon Université, IRD, MIO UM 110, 13288 Marseille Cedex 09, France. Electronic address: melanie.ourgaud@mio.osupytheas.fr.
authors.forename: M
authors.initials: M
authors.lastname: Ourgaud
authors.affiliation: Mediterranean Institute of Oceanography (MIO), Aix-Marseille Université, CNRS, Toulon Université, IRD, MIO UM 110, 13288 Marseille Cedex 09, France.
authors.forename: S
authors.initials: S
authors.lastname: Ruitton
authors.affiliation: Australian National Centre for Ocean Resources and Security, University of Wollongong, NSW 2522, Australia.
authors.forename: J D
authors.initials: JD
authors.lastname: Bell
authors.affiliation: Université de la Nouvelle Calédonie, Laboratoire LIVE and LABEX «Corail», BP R4, 98851 Nouméa Cedex, New Caledonia.
authors.forename: Y
authors.initials: Y
authors.lastname: Letourneur
authors.affiliation: GIS Posidonie & Mediterranean Institute of Oceanography (MIO), Aix-Marseille Université, Station Marine d'Endoume, 13007 Marseille, France.
authors.forename: J G
authors.initials: JG
authors.lastname: Harmelin
authors.affiliation: Mediterranean Institute of Oceanography (MIO), Aix-Marseille Université, CNRS, Toulon Université, IRD, MIO UM 110, 13288 Marseille Cedex 09, France.
authors.forename: M L
authors.initials: ML
authors.lastname: Harmelin-Vivien
mesh_terms: D035961:Alismatales / Q000502:physiology; D000818:Animals; D044822:Biodiversity; D057231:Climate Change; D005399:Fishes / Q000502:physiology*; D020387:Food Chain; D011156:Population Density; D012722:Sewage / Q000032:analysis*; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D012722:Sewage; D062065:Wastewater
keywords: Fish assemblages; Mediterranean Sea; Posidonia oceanica seagrass; Sewage impact; Trophic structure