Aggregation in marine biological valuation - fitness consequences
This article continues the discussion about developing criteria for valuing marine biological diversity. It considers the difficulties of defining areas where aggregation of species may occur, especially for widely dispersed highly mobile species. It is part of a summary of the 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.
- As there could be overlap between the criteria 'aggregation' and 'fitness consequences' both criteria were lumped together.
- Lumping both criteria should avoid that certain subzones are scored twice for the same reason (e.g. reproductive areas where species aggregate).
- The definitions of both criteria, as mentioned in the working document, should be merged to cover this lumped criterion: “Degree to which an area is a site where most individuals of a species are aggregated for some part of the year or a site which most individuals use for some important function in their life history or a site where some structural property or ecological process occurs with exceptionally high density either/or the degree to which an area is a site where the activity(ies) undertaken make a vital contribution to the fitness (= increased survival or reproduction) of the population or species present”.
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)