Ecological assessment of soft bottom benthic communities in northern Spanish estuaries

摘要: Abstract The implementation of the Water Framework Directive requires classification ecological quality status benthic macroinvertebrates in costal and transitional waters. uncertainty complexity this task have lead to creation specific Geographical Intercalibration Groups (GIGs) for different ecoregions types water bodies established. In framework, several metrics are under study United Kingdom, Spain Denmark North East Atlantic coastal waters (NEA-GIG). All them include their formulations AMBI index. Nevertheless, few advances been made relation This paper aims test suitability those methodological procedures application Northern Spanish estuaries. results show evident divergences among methods, although correlations corresponding ratios (EQRs) good. Thus, we think that it may be necessary modify boundaries between each category adjust reference conditions variety community-types existing estuarine bodies. However, some problems arise assessment naturally stressed communities. situation, found an overall dominance species tolerant organic enrichment all categories low range variation aspect introduces ability index detect a deleterious effect these communities stressed. On other hand, sites achieve good according used, even though number opportunistic was high. use combined approaches incorporate physicochemical condition sediments would straightforward approach reduce risk failing assignation category.