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 224

7.1 Introduction
Marine environments provide significant benefits to man, for example through the provision
of seafood and other resources worth trillions of dollars per annum, regulation of the Earth's
climate, and the modulation of global biogeochemical cycles (Holmlund and Hammer,
1999 ) , water quality maintenance (Worm et al ., 2006 ), and also cultural and aesthetic bene-
fits (Lewis, 2012 ) . In spite of its clear importance, the marine environment is subject to huge
pressure from anthropogenic sources. These pressures arise from inter alia the overexploit-
ation of marine species, nutrient loading from land-based agriculture, underwater noise, the
introduction of invasive species, and increasing oceanic acidification and habitat degrada-
tion. The threats are frequently interlinked. Further, in terms of biodiversity loss, Lotze et
al . ( 2006 ) estimate that the human exploitation of marine species is responsible for 96% of
species extinctions.
The ecosystem based approach (EBA) is a managed response to these anthropogenic
impacts on marine ecosystems. The aim of the EBA is to facilitate the protection, recovery,
and sustainable use of marine ecosystems, applying a multi-sector approach. Any manage-
ment approach is likely to entail trade-offs, in the sense that there are some stakeholders
who will realize net benefits from the management intervention and others that will incur
net losses. There are winners and losers even within a body of stakeholders (e.g. fishermen).
Further, one significant broad stakeholder group is 'wider society', and it is important to
capture broader social welfare changes arising from any management intervention.
There is considerable variability in the extent to which the benefits and costs arising
from applying the EBA are measurable, and also the extent to which they can be valued in
monetary terms. For instance, changes in fish stocks have a relatively direct market value,
whereasotherbenefits(suchasafeelingofwell-beingarisingfromtheaestheticsofthemar-
ine landscape) are much less tangible. This is where the burgeoning literature on ecological
economics can contribute in the policy domain. In economic terms, changes in ecosystems
can realize welfare effects even if these changes do not have a direct market price. For in-