title: A multivariate index based on the seagrass Posidonia oceanica (POMI) to assess ecological status of coastal waters under the water framework directive (WFD).
abstract: We propose here a multivariate index based on structural and functional attributes of the Posidonia oceanica ecosystem (Posidonia oceanica multivariate index: POMI) to assess the ecological status of coastal waters following WFD requirements. POMI is based on the combination, through principal component analysis, of physiological, morphological, structural and community level seagrass descriptors (or metrics), univocally related to environmental quality. Scores on the first axis are normalised to a 0-1 scale (EQR) using reference and worst sites. The index was tested by sampling 22 seagrass beds in the Catalan coast (ca. 500 km, NW Mediterranean). The results show a clustering of variables on both sides of the first axis of the PCA, indicating a common relation of all metrics with ecological status. Moreover, the values (EQR) obtained reflect human pressure levels. The proposed index allows a practical and relatively simple assessment of the ecological status of coastal waters, and contains a considerable amount of ecological information, which can be useful for managing purposes.
authors.affiliation: Departamento de Ecología, Facultad de Biología, Universidad de Barcelona, Avda. Diagonal 645, 08028 Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Romero
authors.forename: Begoña
authors.initials: B
authors.lastname: Martínez-Crego
authors.forename: Teresa
authors.initials: T
authors.lastname: Alcoverro
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez
mesh_terms: D035961:Alismatales / Q000737:chemistry / Q000254:growth & development*; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards*; D007391:International Cooperation / Q000331:legislation & jurisprudence; D008522:Mediterranean Sea; D019216:Metals, Heavy / Q000032:analysis; D008962:Models, Theoretical; D015999:Multivariate Analysis; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D011156:Population Density; D025341:Principal Component Analysis; D012015:Reference Standards; D013030:Spain; D013455:Sulfur / Q000032:analysis
chemical_list: D019216:Metals, Heavy; D010758:Phosphorus; D013455:Sulfur; D009584:Nitrogen