Using MEDOCC (MEDiterranean OCCidental) Index to Evaluate the Ecological Status of Catalan Coastal Waters (Northwestern Mediterranean Sea) Over Time and Depths

Abstract

The Ecological Status (ES) of littoral coastal waters from Catalonia (Northwestern Mediterranean Sea) has been evaluated between 2002 and 2010 using MEDOCC (MEDiterranean OCCidental) index. Macroinvertebrate assemblages inhabiting both littoral fine sands (<20 m depth) and littoral sandy muds (25–35 m depth) have been sampled. The relative abundance of four Ecological Groups (e.g., sensitive, indifferent, tolerant, and opportunistic taxa) has been studied along a disturbance gradient. Sensitive taxa are often present in disturbed situations, and tolerant species are usually associated with the presence of opportunistic taxa, both in fine sands and muddy sediments. Sensitive species dominate in sandy habitats, while tolerant species dominate in muddy bottoms. The ES of Catalan coastal waters measured with the samples collected in littoral fine sands has improved since 2002, and all locations rated above a good ES in 2010. The ES measured with the samples collected in littoral sandy muds was above a good ES although the Ecological Quality Ratio (EQR) was always lower than in littoral fine sands. Consequently, the ES of all water bodies was rated as good or high ES in 2010, and no water body was at risk of noncompliance of Water Framework Directive (WFD) requirements.