The importance of geographical scale in marine biological evaluation
This article forms part of discussions centred around valuing the marine environment at a workshop held from 6 to 8 December 2006 at Ghent (Belgium). The workshop was a joint venture of the EU CA ENCORA (http://www.vliz.be/projects/encora/) 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. The workshop report can be downloaded at (http://www.marbef.org/documents/Theme3/GhentWS/report.pdf). This article specifically considers the use of the relationship between national, regional and global scales in assessing marine nature conservation features.
Proportional importance can be assessed on three different levels: on a global level, a regional level and a national level.
‘Global importance’ is defined as the proportion of the global extent of a feature (habitat/seascape) or proportion of the global population of a species occurring in a certain subarea within the study area.
‘Regional importance’ is defined as the proportion of the regional (e.g. NE Atlantic region) extent of a feature (habitat/seascape) or proportion of the regional population of a species occurring in a certain subarea within the study area.
‘National importance’ is defined as the proportion of the national extent of a feature (habitat/seascape) or proportion of the national population of a species occurring in a certain subarea within territorial waters.
Proportional importance measures the proportion of the national, regional and/or global resource of a species or feature which occurs within a subzone of the study area. While the ‘aggregation’ criterion investigates whether a high percentage of the species population at the scale of the study area is clustered within certain subzones of that area, the ‘proportional importance’ criterion investigates whether a high percentage of the species’ population at a national (provided that the national scale is greater than the scale of the study area), regional and/or global scale can be found in the study area, regardless if this proportion is clustered within adjacent subzones.
Application of the criterion
To assess this criterion, data on the extent of marine features or population data of individual species are needed.
When population data are lacking, it may be possible to use available abundance data for species within the study area, and determine the national importance of subzones for these species. This criterion was first defined by Connor et al. (2002) and adapted by Lieberknecht et al. (2004a, 2004b), who also defined thresholds for the term ‘high proportion’. These thresholds are similar to those in the criteria guidance of OSPAR (2003).
It was decided at the workshop on marine biological valuation that no thresholds would be set in the definition of the criterion, since they are very scale-dependent and should therefore be set for every case study separately.
Marine biological valuation maps represent the biological values of the different subzones considered, relative to each other, but incorporation of the proportional importance criterion aims at comparing certain features or properties with the wider environment of the study area, attaching extra value to subzones where a high proportion of the population of a species occurs. It could also be possible to include the genetic (e.g. restricted distribution of a certain genetic stock) or community (e.g. restricted distribution of a defined community type) level.
These paragraphs are based on the paper of Derous et al. (2007). A concept for biological valuation in the marine environment. Oceanologia 49 (1). See FLANDERS MARINE INSTITUTE web site at  for further information and to download a copy of the paper.
- Derous S., Agardy T., Hillewaert H., Hostens K., Jamieson G., Lieberknecht L., Mees J., Moulaert I., Olenin S., Paelinckx D., Rabaut M., Rachor E., Roff J., Stienen E.W.M., van der Wal J.T., Van Lancker V., Verfaillie E., Vincx M., Weslawski J.M., Degraer S. (2007). A concept for biological valuation in the marine environment. Oceanologia 49 (1).
- Connor D.W., Breen J., Champion A., Gilliland P.M., Huggett D., Johnston C., Laffoley D.d'A., Lieberknecht L., Lumb C., Ramsay K., Shardlow M. (2002). Rationale and criteria for the identification of nationally important marine nature conservation features and areas in the UK: Version 02.11. Peterborough, Joint Nature Conservation Committee (on behalf of the statutory nature conservation agencies and Wildlife and Countryside Link) for the Defra Working Group on the Review of Marine Nature Conservation Working paper.
- Lieberknecht L.M., Vincent M.A., Connor D.W. (2004a). The Irish Sea Pilot: Report on the identification of nationally important marine features in the Irish Sea. Joint Nature Conservation Committee report No 348.
- Lieberknecht L.M., Carwardine J., Connor D.W., Vincent M.A., Atkins S.M., Lumb C.M. (2004b). The Irish Sea Pilot, Report on the identification of nationally important marine areas in the Irish Sea. Joint Nature Conservation Committee report No 347.
- BWZee workshop definition (2004)
- OSPAR (2003). Criteria for the identification of species and habitats in need of protection and their method of application (The Texel-Faial criteria). Meeting of the OSPAR Commission in Bremen, 23-27 June 2003, OSPAR 03/17/1-E, Annex 5.