title: Optimization of an "in situ" subtidal rocky-shore sampling strategy for monitoring purposes.
abstract: This study compared 2 standardized protocols to monitor subtidal rocky shores. We tested 2 sampling methods (temporal unit and quadrat) to assess the efficiency of extracting biota parameters (diversity, abundance, and biomass) of macroalgae, Mollusca, and Porifera with respect to time-cost and the number of sampling units. Species richness and occurrence of rocky subtidal habitats were better described by visual censuses than by quadrats. The same estimated richness was provided by the 2 methods. The association of a visual census and a quadrat was the most efficient way for responding to the requirements. A minimum of 5 sampling units per discrete area is recommended for accurately describing habitats. Then, we tested the sensitivity of the proposed protocol on the Bizeux Islet to study the variations of community structures according to depth and station. Based on the results, recommendations for monitoring purposes have been proposed according to European directives.
authors.affiliation: Muséum national d'Histoire naturelle, DMPA, UMR 7208 BOREA, Centre de recherche et d'enseignement sur les systèmes côtiers, 38 rue du Port Blanc, 35800 Dinard, France. Electronic address: reg.gallon@gmail.com.
authors.forename: R K
authors.initials: RK
authors.lastname: Gallon
authors.forename: F
authors.initials: F
authors.lastname: Ysnel
authors.forename: E
authors.initials: E
authors.lastname: Feunteun
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000145:classification* / Q000254:growth & development; D044822:Biodiversity; D018533:Biomass; D058448:Biota; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D008974:Mollusca; D011161:Porifera; D012624:Seaweed
keywords: European directives; Methodology; Rocky subtidal assessment; Standardized; Western France