, Volume 579, Issue 1, pp 187-197,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 29 Dec 2006

Assessment metrics for littoral seagrass under the European Water Framework Directive; outcomes of UK intercalibration with the Netherlands


Under the Water Framework Directive (WFD) taxonomic composition, presence of disturbance sensitive species, abundance and cover are stated attributes for monitoring the status of marine angiosperms; a biological quality element required for assessment of environmental condition. Member States (MS) are required to devise metrics for assessing these attributes to establish ecological status of water bodies. Furthermore the Directive requires intercalibration of metrics and data between MSs. Seagrass are the only truly marine angiosperms. The proposed suites of UK and Dutch metrics for assessing the specified seagrass attributes are described and comparisons made. UK and Dutch metrics are intercalibrated through testing against each nationality’s seagrass data. Strong agreement is established in the outcomes of the two suites of tools; >83%. Differences in outcomes are usually due to lack of availability of raw data. Importantly, where outcomes differ they still fall on the same side of the Good/Moderate boundary.

Handling editor: K. Martens
An erratum to this article is available at http://dx.doi.org/10.1007/s10750-007-0698-2.