Challenges in using valuation in ecosystem-based management in a marine context: the case of UK Marine Protected Area designation - Ocean Sustainability in the 21st Century - page 248

For some applications of the ecosystem approach to marine management it might be
possible to provide a direct estimation that is specific to the habitat and service in question.
Since only aggregate provisioning estimates were available for UK marine ecosystems, it
was necessary to apportion this total provisioning across all habitats. So for instance, what
contribution does the totality of aphotic reef in the UK make to the totality of nutrient cyc-
ling provision across all UK marine ecosystems?
This apportioning was dependent on the service and there were four variants. For four
of the seven services (food provisioning; raw materials; nutrient cycling; gas and climate
regulation) the apportioning was based on two factors: (1) the extent of the habitat in hec-
tares; (2) the average service provisioning for a 'typical' hectare. Each of the habitats was
scored in the range 1-3 to determine the relative contribution of one hectare. For instance,
'aphotic reef' was scored '1' for all four services whereas 'shelf mud plain' was scored '3',
i.e. it is assumed that one hectare of shelf mud provides around three times as much nutri-
ent cycling as one hectare of aphotic reef.
This is then coupled with extent data. The total area of aphotic reef is 10,968km 2 or
1.8% (across all UK marine habitats), whereas the total area of shelf mud is 44,605km 2 or
7.3%. Since the respective scores were 1 and 3, it is estimated that the sum of all aphotic
reef provides around 0.7% of the total nutrient cycling across all UK marine habitats,
whereas shelf mud plain provides 22.0%.
For disturbance prevention and alleviation, a similar coding system was applied, but
modified to allow for distance to shore. For the two remaining services (cognitive value;
leisure and recreation) allocation was arbitrary, i.e. an equal allocation across all habitat
types, as there was insufficient biophysical evidence to support any alternative allocation.
There is little doubt that the allocation method set out here and in Moran et al. ( 2007 )
can be improved upon, and indeed within the EC ODEMM project the methodology being
developed and applied is more rigorous. For instance, a review of the marine ecosystem
service valuation literature revealed over 50 studies on leisure and recreation, potentially
allowingformeta-regression analysistodeterminethelinkbetweenvalueestimates forthis
service and ecological characteristics. But the point to be made again is that for the MCZ