Marine protected areas (MPAs) are key tools to maintain coastal ecosystems. However, many reserves are characterized by several problems related to zonings that preclude important areas from economic activities, determining a strong hostility by local populations. Thus, estimations of marine economic values-in-use are needed for protection of marine ecosystems, in order to find the best compromise between conservation priorities and local population needs.

This study implemented algorithms (Systematic Costs Assessment, SCA) to create maps where monetary values of the main human activities can be assigned and can be used in conservation planning optimization software. The algorithms are implemented in the Gulf of Naples (centre Tyrrhenian Sea, Italy) as study area example.

The authors suggest the use of SCA in future marine conservation plans, since it reduces stakeholders hostility and allow estimations on the maximum investments that can be afforded for specific conservation actions facilitating conservation design phase.

It his highlighted that information coming from SCA also allows to identify groups of stakeholders and to define possible management options which may affect costs and benefits of marine biodiversity conservation.

It is concluded that SCA is a flexible approach where no long and costly sampling campaigns are always needed.

Appolloni L, Sandulli R, Vetrano G, Russo GF (2018) A new approach to assess marine opportunity costs and monetary values-in-use for spatial planning and conservation; the case study of Gulf of Naples, Mediterranean Sea, Italy. Ocean & Coastal Management 152:135-144