title: Biomonitoring of metals under the water framework directive: detecting temporal trends and abrupt changes, in relation to the removal of pollution sources.
abstract: Temporal trends in metal concentrations, i.e. Ag, Cd, Cu, Cr, Hg, Ni, Pb and Zn, measured in soft tissues of Mytilus galloprovincialis mussels and Crassostrea gigas oysters collected from estuarine waters within the Basque Country (Bay of Biscay), have been investigated to determine if actions undertaken have improved the environmental quality of rivers and estuaries. Data compiled between 1990 and 2010 have been analysed statistically, applying the Mann-Kendall and the Mann-Whitney-Wilcoxon tests. Moreover, in those cases with significant trends, the Kolmogorov-Zurbenko Adaptive (KZA) filter was applied to detect abrupt changes. Results showed significant decreasing trends for some metals, i.e. Ni, Cu, Pb and Zn, and differences between medians. Trend lines showed abrupt changes occurring between 1998 and 2002. Therefore, observed downward trends were related to increased wastewater treatment and diversions of discharges to ocean, implemented mainly during 2000-2002.
authors.affiliation: Marine Research Division, AZTI-Tecnalia Foundation, Herrera Kaia, Portualdea, z/g, 20110 Pasaia, Spain. osolaun@azti.es
authors.forename: O
authors.initials: O
authors.lastname: Solaun
authors.forename: J G
authors.initials: JG
authors.lastname: Rodríguez
authors.forename: A
authors.initials: A
authors.lastname: Borja
authors.forename: M
authors.initials: M
authors.lastname: González
authors.forename: J I
authors.initials: JI
authors.lastname: Saiz-Salinas
mesh_terms: D000818:Animals; D049896:Crassostrea / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods*; D058735:Environmental Policy; D063366:Estuaries; D008670:Metals / Q000032:analysis / Q000378:metabolism*; D049878:Mytilus / Q000378:metabolism; D045483:Rivers / Q000737:chemistry; D013030:Spain; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D014877:Water Pollution, Chemical / Q000331:legislation & jurisprudence* / Q000706:statistics & numerical data
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical