Assessing the capacity of European regional seas to supply ecosystem services using marine status assessments
Graphical abstract
Introduction
Ecosystems provide many services to humans, with marine systems contributing a significant proportion of those (estimates range from 40 to 70% of the total value of services, Costanza et al. (2014)). These services include provision of food and raw materials, climate regulation and opportunities for recreation, amongst others. Yet, the supply of ecosystem services (ESs) is under threat from human activities (MA, 2005; Costanza et al., 2014; IPBES, 2019). The importance of ESs is increasingly recognised in policy instruments, at international (e.g. the Sustainable Development Goals (UN, 2015)), regional (e.g. the European Union's (EU) Biodiversity Strategy to 2020 (EC, 2011b)), and national levels (e.g. the UK National Ecosystem Assessment (Nea, 2011)). In the face of increasing threats, we urgently require the means to assess whether the supply of ESs from our ecosystems can be sustained, and to identify where management intervention is required to ensure this.
ES assessments vary in their approach to linking ecosystem structures, processes and functions with ESs. Approaches include relating changes in service supply to changes in biodiversity or species richness in general (e.g. Worm et al., 2006); have been based on spatial assessments, particular geographical areas of habitats (e.g. using Corine land cover maps, Burkhard et al. (2012)); particular functions (e.g. carbon storage, Lavery et al. (2013)); or particular taxa (e.g. oyster reefs, Grabowski et al. (2012)). For services not readily linked to specific parts of the ecosystem, such as many cultural services, sociocultural or economic information has been used to document use, demand or value (Garcia Rodrigues et al., 2017). Several studies follow the approach of habitat mapping and testing specific management scenarios (e.g. Arkema et al., 2015; Cabral et al., 2015; Hooper et al., 2017). For example, Hooper et al. (2017) used mapped marine benthic habitats to assess the effects changes to fishing and aggregate extraction activities would have on nursery habitat provision, carbon sequestration and waste remediation, based on the potential of habitats to supply those services, and their sensitivity to those activities. In general, such studies tend to be highly quantitative and based on location-specific data. What is still needed however, are policy relevant approaches at national and regional scales, as environmental policies often require assessments that can track their overall success at such scales. For example, the EU Marine Strategy Framework Directive (MSFD, EC, 2008) requires that marine assessment and management efforts are coordinated at the level of European regional seas, called ‘EU marine regions’.
To date, European policy-relevant assessment approaches have assessed ESs at large regional scales but have struggled to adequately characterize the ESs of the marine environment (e.g. Mace et al., 2015; Maes et al., 2016). This is because policy generated data and information on ESs, in particular spatial data, are often lacking for large marine ecosystems or regional seas, preventing such assessments. In the EU, the policies that have developed the ESs concept are non-binding in nature (Bouwma et al., 2018), and EU Member States are unlikely to collect the additional required information to directly assess state and trends in marine ESs due to limited resources for monitoring (although see Liquete et al. (2016) for some examples based on modelling approaches). Whilst the marine environment may thus continue to be seen as an unknown realm, where assessments of ESs are severely limited in their scope (Nash et al., 2017) we have a wealth of information at policy-relevant scales on state and trends in marine ecosystem components (e.g. habitats and species groups), and on the pressures acting upon them (albeit with varying degrees of confidence). In the EU, much of this comes through the reporting obligations of EU marine relevant policies (e.g. the MSFD (EC, 2008), the Water Framework Directive (WFD) (EC, 2000), the Habitats Directive (EC, 1992) and the Common Fisheries Policy (CFP) (EC, 2013)) that require managers to routinely monitor parts of the ecosystem. We took the starting point here, that it is currently more achievable to use the existing information coming from established monitoring programmes to assess the marine ecosystem's capacity to supply ESs. Nevertheless, the information coming from those policies has not been collected or reported with marine ES assessments in mind. Additionally, this information tends to take the shape of classified ‘status’ assessment products and needs to be re-interpreted.
The approach of using ecosystem state information to assess the marine ecosystem's capacity to supply ESs, relies on the concept that the integrity of the ecosystem, of its structures, processes and functions, underpins all the services that can be supplied to people (Burkhard et al., 2012). If the state of the ecosystem is degraded, it is likely to compromise the supply of services but this is not for all services, and not to the same degree. Recent work shows, for example, that marked changes in benthic species composition has limited impacts on the functioning of the marine system, as the system shows functional resilience through species substitutions that conserve the functional traits present (Caswell and Frid, 2017). These resilient systems can, though, show a catastrophic collapse in functioning (and hence service supply) at high levels of perturbation. We need an understanding of how ecosystem functioning can lead to service supply through identifying the ecosystem state-service relationship. This relationship is better understood in some cases than others, e.g., we know a lot about fish population dynamics leading to the supply of seafood (Piet et al., 2017), and about nutrient cycling in benthic ecosystems that can lead to waste remediation (Watson et al., 2016).
We follow the concept that the state of ecosystem components can inform us about the state of ESs, through indicating the capacity of the ecosystem to supply them (supply-side assessment approach). We aimed to develop and test an approach that can assess the capacity of marine ecosystems to supply ESs at a regional sea scale, using assessment information on marine ecosystem status and trends directly from existing policy reporting. We wanted to develop a framework that can work for data poor and rich situations, so that a common approach can be used across marine regions. The approach we present was developed across European regional seas, and includes examples of its application at different scales in the North East Atlantic Ocean, the Mediterranean Sea and the Baltic Sea, for marine ESs that have different relevant information availabilities. We use information reported by EU Member States to fulfil EU and other environmental policy objectives to inform us about (changes in) ecosystem state and integrate this to provide results relevant at the regional sea scale. Using our understanding of the ecosystem state-service relationship, we then re-interpret this information to inform us about the capacity of regional seas to supply services.
Section snippets
The MECSA framework overview
The marine ecosystem capacity for service supply assessment (MECSA) aims to assess the capacity of the ecosystem to supply ESs, informed by its current state and trends in state. By ‘capacity’, we mean the potential of the ecosystem to supply ESs, which depends on its state. We do not assess actual supply, because this would require also accounting for the flow of services from the ecosystem through human use and that is not the focus of this approach. We consider capacity because the
Case study application
Three case studies – one each of a cultural, regulation and maintenance, and provisioning service, were considered, in order to illustrate the approach across three, quite different types of services.
Under cultural services, recreation and leisure from whale watching was assessed for the Mediterranean Sea. Tourism is a valuable industry along the European Mediterranean coast; around one-third of global tourism is based around the Mediterranean Sea (Randone et al., 2017). Whale and dolphin
Discussion
We developed an approach to assess the state and the change in state of the marine ecosystem's capacity to supply services that: (1) makes use of available, policy-generated information on marine ecosystem state, (2) uses existing knowledge of ecosystem functioning to understand how that ecosystem state relates to its capacity for service supply, and (3) is applied at a regional sea (policy relevant) scale. We carried out three case studies in developing the approach and found that the state of
Conclusion
Decreasing ecosystem capacity to supply services is recognised as a critical issue for sustainable development and in supporting a growing global population (UN, 2015). In the EU, environmental policies, such as the MSFD and the Biodiversity Strategy to 2020, aim to regulate the sustainability of human activities using nature and ecosystems, and ensure the continued supply of ecosystem services. The numerous environmental policies in place, are often there at great cost to and effort by the
Contributors
FC, LAR, CF, ERG derived the main concepts and developed the method, GP, FC, LAR, CF carried out the seafood service assessments, FC, LW, CF carried out the waste removal and storage service assessment, FC, CF carried out the recreation and leisure service assessment, FC, LAR, GP, CF, ERG wrote the manuscript. All authors reviewed the manuscript.
Declaration of competing interest
The authors have no competing interests to declare.
Acknowledgements
This work was produced under a European Topic Centre grant agreement (Negotiated Procedure EEA/NSV/14/002) with the European Environment Agency (EEA). Opinions expressed are those of the authors and do not necessarily reflect the official opinion of the EEA or other European Community bodies and institutions. The full detail of the work presented here is found in Culhane et al. (2019a), available at: https://www.eionet.europa.eu/etcs/etc-icm/products/icm-reports.
References (82)
- et al.
An economic–ecological model to evaluate impacts of nutrient abatement in the Baltic Sea
Environ. Model. Software
(2014) - et al.
Identification, definition and quantification of goods and services provided by marine biodiversity: implications for the ecosystem approach
Mar. Pollut. Bull.
(2007) - et al.
Adoption of the ecosystem services concept in Eu policies
Ecosyst. Serv.
(2018) - et al.
Mapping ecosystem service supply, demand and budgets
Ecol. Indicat.
(2012) - et al.
Marine habitats ecosystem service potential: a vulnerability approach in the Normand-Breton (Saint Malo) Gulf, France
Ecosyst. Serv.
(2015) - et al.
Seafloor ecological functioning over two decades of organic enrichment
Mar. Pollut. Bull.
(2018) - et al.
Changes in the global value of ecosystem services
Global Environ. Change
(2014) - et al.
Risk to the supply of ecosystem services across aquatic ecosystems
Sci. Total Environ.
(2019) - et al.
Towards an understanding of the spatial relationships between natural capital and maritime activities: a Bayesian Belief Network approach
Ecosyst. Serv.
(2019) - et al.
Assessing the sensitivity of ecosystem services to changing pressures
Ecosyst. Serv.
(2017)