title: Effects of subtle pollution at different levels of biological organisation on species-rich assemblages.
abstract: We investigated effects of subtle nutrient enrichment and metal pollution on different levels of biological organization (i.e. whole assemblage, population and individual) of species-rich assemblages. We used rockpools as model system, applying a multi-factorial sampling design to test hypotheses on differences between disturbed and reference locations. Results indicated that disturbed and reference locations supported similar assemblages, as well as individual fitness-related life-traits were ineffective to discriminate between the two conditions. In contrast, assemblages responded to pollution through a reduction of the abundance of sensitive species and a proliferation of tolerant species, although these alterations were detectable only once the influence of dominant taxa was down-weighed by data transformation. Present findings suggest that, contrarily to individual level variables, assemblage structure after data transformation and patterns of distribution and abundance of differently sensitive taxa would be a powerful tool to detect effects of subtle pollution on species-rich assemblages.
authors.affiliation: CIIMAR/CIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Rua dos Bragas, 289, 4050-123 Porto, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4150-181 Porto, Portugal. Electronic address: mrubal@ciimar.up.pt.
authors.forename: Marcos
authors.initials: M
authors.lastname: Rubal
authors.affiliation: CIIMAR/CIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Rua dos Bragas, 289, 4050-123 Porto, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4150-181 Porto, Portugal.
authors.forename: Puri
authors.initials: P
authors.lastname: Veiga
authors.affiliation: CIIMAR/CIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Rua dos Bragas, 289, 4050-123 Porto, Portugal.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Reis
authors.affiliation: CIIMAR/CIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Rua dos Bragas, 289, 4050-123 Porto, Portugal.
authors.forename: Iacopo
authors.initials: I
authors.lastname: Bertocci
authors.affiliation: CIIMAR/CIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Rua dos Bragas, 289, 4050-123 Porto, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre s/n, 4150-181 Porto, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Sousa-Pinto
mesh_terms: D000818:Animals; D003445:Crustacea; D017753:Ecosystem; D004787:Environmental Pollution; D008670:Metals / Q000032:analysis; D049878:Mytilus; D011174:Portugal; D012908:Snails
chemical_list: D008670:Metals
keywords: Biological levels of organization; Eutrophication; Metals; Rocky shore; Species rich assemblages; Subtle pollution