Choice of data for marine biological evaluation
This article stems from discussions held during a workshop on marine biological valuation, held from 6 to 8 December 2006 at Ghent (Belgium). The workshop was a joint venture of the EU CA ENCORA (http://www.encora.org) and the EU NoE MARBEF (http://www.marbef.org). Both Theme 7 within ENCORA and Theme 3 within MARBEF deal with marine/coastal biological valuation and the workshop aimed to reach a consensus on this topic.
Every ecosystem component map should be provided with a reliability estimate (e.g. achieved by multivariate analysis and principle components analysis). On the basis of these reliability labels one can decide whether the map should be used to produce the final valuation map.
In the ideal world, all component maps provide full spatial coverage of the study area. However, in the real world there are often gaps, which might or might not be filled by interpolation. It could be useful that when different component maps are combined, only the subareas that have overlap in coverage are shown (while the other subareas become ‘blanc’).
The grids (subareas) of the separate components do not need to be of the same size, but do need to overlap (e.g. 4 in 1).
There should be at least one component map to give an idea of the value of the subareas, but off course the integration of more maps will increase the confidence level of the valuation.
Data taken along transects (e.g. beam trawls) can easily be extrapolated to grids.
These paragraphs reflect the main discussion outcomes of the ENCORA Theme 7-MARBEF Theme 3 workshop on marine biological valuation (6-8 December 2006, Gent, Belgium). (http://www.marbef.org/documents/Theme3/GhentWS/report.pdf)