title: A multiple index integrating different levels of organization.
abstract: Many methods in freshwater biomonitoring tend to be restricted to a few levels of biological organization, limiting the potential spectrum of measurable of cause-effect responses to different anthropogenic impacts. We combined distinct organisational levels, covering biological biomarkers (histopathological and biochemical reactions in liver and fish gills), community based bioindicators (fish guilds, invertebrate metrics/traits and chironomid pupal exuviae) and ecosystem functional indicators (decomposition rates) to assess ecological status at designated Water Framework Directive monitoring sites, covering a gradient of human impact across several rivers in northern Portugal. We used Random Forest to rank the variables that contributed more significantly to successfully predict the different classes of ecological status and also to provide specific cut levels to discriminate each WFD class based on reference condition. A total of 59 Biological Quality Elements and functional indicators were determined using this procedure and subsequently applied to develop the integrated Multiple Ecological Level Index (MELI Index), a potentially powerful bioassessment tool.
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: rcortes@utad.pt.
authors.forename: Rui
authors.initials: R
authors.lastname: Cortes
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: shughes@utad.pt.
authors.forename: Samantha
authors.initials: S
authors.lastname: Hughes
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: acoimbra@utad.pt.
authors.forename: Ana
authors.initials: A
authors.lastname: Coimbra
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: smonteir@utad.pt.
authors.forename: Sandra
authors.initials: S
authors.lastname: Monteiro
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: pereiravr@gmail.com.
authors.forename: Vítor
authors.initials: V
authors.lastname: Pereira
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: molopes@utad.pt.
authors.forename: Marisa
authors.initials: M
authors.lastname: Lopes
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: spereira@utad.pt.
authors.forename: Sandra
authors.initials: S
authors.lastname: Pereira
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: estorninho@hotmail.com.
authors.forename: Ana
authors.initials: A
authors.lastname: Pinto
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: asampaio@utad.pt.
authors.forename: Ana
authors.initials: A
authors.lastname: Sampaio
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: santoscfp@gmail.com.
authors.forename: Cátia
authors.initials: C
authors.lastname: Santos
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: joao@utad.pt.
authors.forename: João
authors.initials: J
authors.lastname: Carrola
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: jjesus@utad.pt.
authors.forename: Joaquim
authors.initials: J
authors.lastname: de Jesus
authors.affiliation: Centro de Investigação em Tecnologias Ambientais e Biológicas (CITAB) da Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, Apartado 1013, 5000-801 Vila Real, Portugal. Electronic address: simonev@utad.pt.
authors.forename: Simone
authors.initials: S
authors.lastname: Varandas
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D003247:Conservation of Natural Resources / Q000379:methods*; D004463:Ecology; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D005399:Fishes / Q000378:metabolism; D005880:Gills / Q000378:metabolism; D007448:Invertebrates / Q000378:metabolism; D011174:Portugal; D045483:Rivers / Q000737:chemistry*
chemical_list: D015415:Biomarkers
keywords: Bioindicators; Biomarkers; Fishes; Invertebrates; Random forest; WFD