Ecosystem condition underpins the generation of ecosystem services: an accounting perspective

Assessing the economic value of Posidonia oceanica (L.) at Tremiti Islands (Mediterranean Sea): An ecosystem condition-based approach

In the context of limiting global warming, the seagrass Posidonia oceanica (L.) gained the centrality of several international climate change mitigation projects being the most effective carbon storage sink among Mediterranean seagrasses. To assess and monitor the change of environmental conditions and economic values of natural resources, the present study moves from the insights of the System of Environmental-Economic Accounting - Ecosystem Accounting to assess the economic value of the carbon sequestration and storage capacity of the Mediterranean-endemic seagrass P. oceanica at the Tremiti Islands Marine Protected Area. The economic value is compared across: i. the reference study by Pergent-Martini et al.; ii. the ecological condition-based approach; and iii. the unit value transfer. Based on the obtained outcomes, an ecosystem-based approach would prevent biases in the accounting of the ecosystem-service provision capacity of P. oceanica and help the policy maker to implement adequate public investment policies to mitigate its overall degradation.

Marine and coastal accounts for Small Island Developing States: A case study and application in Grenada

In recent decades, a concerted effort has been made to define methodologies and frameworks to account for the contribution of the natural environment to national wealth and its role in fulfilling societal and economic needs. The linkages between natural capital and human well-being are even stronger in low-income and vulnerable countries, such as Small Island Developing States (SIDS). This is particularly true for coastal and marine ecosystems and for SIDS, considering that a large portion of their population live along the coast. Therefore, SIDS would greatly benefit from systematically assessing and recording the condition and services provided by marine and coastal habitats in ecosystem accounts. Applications of accounting frameworks to marine and coastal habitats, however, are still under development. Through a case study in the Caribbean Island of Grenada, we explore SIDS readiness to develop marine and coastal natural capital accounts, in particular framed within the guidelines of the United Nations System of Environmental-Economic Accounting Ecosystem Accounting (SEEA-EA). We find that, while data to compile accounts of ecosystems extent exist and may be suitable for accounting, data related to ecosystem condition are very limited. Data gaps significantly constrained the potential approaches to estimate the ecosystem services supply provided by the coastal and marine environment in our natural capital accounts for Grenada. Our case study investigation brings us to suggest initial steps for the development of ecosystem accounts in SIDS, including potential methodologies and approaches and discuss how developing a set of coherent accounts can play a key role in incorporating nature into decision-making.