title: Spatial variability of three benthic indices for marine quality assessment in a subtropical estuary of Southern Brazil.
abstract: Indices based on macrobenthic responses to disturbance remain to be adequately tested for the detection of spatial variability by robust sampling designs. We present herein a congruence test to real-world data of the widely used indices AMBI, M-AMBI and BENTIX in tidal flats of a subtropical estuary. We used a hierarchical sampling design to evaluate the spatial variability of the indices in response to distinct levels of sewage contamination. Indices were then tested for correlations with chemical proxies of contamination and for the similarity of responses. BENTIX and M-AMBI produced over- and underestimations of ecological status. We found a low degree of similarity among indices as an expression of the spatial variation of macrofaunal assemblages on their performances. Only AMBI varied at the contamination scale (10(3)m) and was congruent with physical-chemical proxies. Ambiguous responses indicated effects of natural inputs of organic matter rather than environmental quality associated to sewage.
authors.affiliation: Centro de Estudos do Mar, Universidade Federal do Paraná, Av. Beira-mar s/n°, Pontal do Paraná 83255-976, Brazil. Electronic address: kalinabio@gmail.com.
authors.forename: Kalina Manabe
authors.initials: KM
authors.lastname: Brauko
authors.affiliation: Centro de Estudos do Mar, Universidade Federal do Paraná, Av. Beira-mar s/n°, Pontal do Paraná 83255-976, Brazil.
authors.forename: Fernanda Maria
authors.initials: FM
authors.lastname: de Souza
authors.affiliation: Oceanografía y Ecología Marina, Facultad de Ciencias, Universidad de la República (UdelaR), Montevideo, Uruguay.
authors.forename: Pablo
authors.initials: P
authors.lastname: Muniz
authors.affiliation: Centro de Estudos do Mar, Universidade Federal do Paraná, Av. Beira-mar s/n°, Pontal do Paraná 83255-976, Brazil.
authors.forename: Maurício Garcia
authors.initials: MG
authors.lastname: de Camargo
authors.affiliation: Centro de Estudos do Mar, Universidade Federal do Paraná, Av. Beira-mar s/n°, Pontal do Paraná 83255-976, Brazil.
authors.forename: Paulo da Cunha
authors.initials: Pda C
authors.lastname: Lana
mesh_terms: D000818:Animals; D001938:Brazil; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards; D063366:Estuaries; D007448:Invertebrates / Q000502:physiology*; D012722:Sewage; D062206:Spatial Analysis; D014876:Water Pollution / Q000032:analysis*
chemical_list: D012722:Sewage
keywords: AMBI; BENTIX; Hierarchical analysis; Indicators; M-AMBI; Urban effluents