1 research outputs found
The seagrass Posidonia oceanica as indicator of coastal water quality: Experimental intercalibration of classification systems
7 páginas, 5 figuras, 5 tablas.The pervasive use of ecological indices is increasingly requiring actions of harmonisation. Specifically,
within the EU Water Framework Directive, an important effort in methods intercalibration is being done.
However, a significant limitation in comparability assessment arises from the datasets used, which have
different geographic origins. The purpose of our study was to perform an experimental intercalibration,
where data were collected specifically on a set of common sites and following all the requirements
of the methods being assessed. Three indices based on the marine angiosperm Posidonia oceanica, the
POMI, the BiPo and the PoSte, were applied to sites in three different geographical areas of the western
Mediterranean: Catalonia, Corsica and Southern Italy (Ischia), distant between hundreds and more than
thousands of kilometers. Two indices, POMI and BiPo, showed not only a very good relationship with
human pressures (measured on a common scale for all sites) but also a high comparability, in all aspects
investigated. The differences found for the third one (PoSte) are hypothesised as being due to a different
rationale used to define reference conditions, the different metrics used in the index, and in particular to
a different definition of ecological status in relation to the time scale of the response to anthropogenic
pressures. Our study demonstrates that indices with very different approaches can provide fully reliable
and comparable results.This study was supported by the POSIDONIA Project, set up
within the framework of the Interreg IIIB–MEDOCC Convention.
The laboratory of benthic ecology of the Stazione Zoologica di
Napoli was supported by a research contract of the Italian Environmental
Protection Agency (APAT), for the “Development of methods
and analysis of P. oceanica, according to the Water Framework
Directive” (APAT, 2005–2006).
We are indebted to Mian Vich,Peer reviewe