Use of biotic indices in semi-enclosed coastal ecosystems and transitional waters habitats - Implications for the implementation of the European Water Framework Directive

摘要: This study deals with the application of macrozoobenthos-based biotic indices (BI) within frame implementation European Water Framework Directive. More precisely, this aimed at assessing performance five recently developed methodologies for assessment ecological quality status (EcoQ) in two semi-enclosed, sheltered coastal ecosystems and one transitional water body situated along Western French coast, namely Marennes-Oleron Bay, Arcachon Seine Estuary. showed that these rarely agreed each other, describing very different pictures overall EcoQ three sites. work also clearly underlined limitations approaches, notably dependency most BI resulting classifications on habitat characteristics, more particularly to natural levels sediment silt–clay content location stations subtidal or intertidal. The implication our observations concerning use WFD is discussed terms definition habitat-specific reference conditions necessity adjust thresholds particular occurring semi-enclosed ecosystems. Meanwhile, unmodified severely impaired accurate decision-making managers’ point view.