The biotic and abiotic assets of the marine environment form the “marine natural capital” embedded in the global ocean. Marine natural capital provides the flow of “marine ecosystem services” that are directly used or enjoyed by people providing benefits to human well-being. They include provisioning services (e.g., food), regulation and maintenance services (e.g., carbon sequestration and storage, and coastal protection), and cultural services (e.g., tourism and recreational benefits). In recent decades, human activities have increased the pressures on marine ecosystems, often leading to ecosystem degradation and biodiversity loss and, in turn, affecting their ability to provide benefits to humans. Therefore, effective management strategies are crucial to the conservation of healthy and diverse marine ecosystems and to ensuring their long-term generation of goods and services. Biophysical, economic, and sociocultural assessments of marine ecosystem services are much needed to convey the importance of natural resources to managers and policy makers supporting the development and implementation of policies oriented for the sustainable management of marine resources. In addition, the accounting of marine ecosystem service values can be usefully complemented by their mapping to enable the identification of priority areas and management strategies and to facilitate science–policy dialogue. Given this premise, this study aims to review trends and evolution in the concept of marine ecosystem services. In particular, the global scientific literature on marine ecosystem services is explored by focusing on the following main aspects: the definition and classification of marine ecosystem services; their loss due to anthropogenic pressures, alternative assessment, and mapping approaches; and the inclusion of marine ecosystem services into policy and decision-making processes.

Posidonia oceanica is an endemic seagrass of the Mediterranean Sea, forming extensive meadows and providing valuable ecosystem services underwater as well as on the shore. P. oceanica constantly generates new leaves while shedding the older ones. The latter may be deposited on the shoreline, forming “banquettes” that exhibit variable thickness, ranging from a few centimeters to several meters. These deposits act as natural barriers against coastal erosion, preventing sand loss and dissipating wave energy. Moreover, the degradation of the washed-up leaves releases large amounts of nutrients, relevant for the coastal food web. However, the presence of banquettes in touristic areas is often perceived as a nuisance, thus leading to their removal by local administrations. This study proposes a multidisciplinary approach for the assessment of P. oceanica banquettes along the coastline of the Campania region (Southern Italy), estimating their biomass and the associated concentrations of nutrients and other chemical elements, with the final aim to assess the potential loss of natural capital and ecosystem services due to their removal. Regional estimates show that approximately 40 tons of C are stored annually in the beached biomass, representing a potential carbon loss associated with their removal. The results highlight the crucial role that P. oceanica banquettes play in the blue carbon cycle and provide valuable insights to support their sustainable management.

Among marine habitats, the coralligenous represents one of the most important biodiversity hotspots, also playing an important role in the carbon cycle. Coralligenous is a biogenic habitat of the circalittoral zone formed by calcareous structures built by crustose coralline algae and other assemblages of calcifying organisms. Due to its structural complexity, it is also considered one of the most vulnerable marine habitats, very sensitive to environmental changes, such as climate change, and to other anthropogenic impacts such as fishing activities. Trawling is the most harmful fishing method that is causing the degradation of large areas of coralligenous reef concretions. Small-scale and sport fishing can also cause damage to the most sensitive organisms of the coralligenous habitat that can be damaged or removed by fishing gear, both during the fishing activity and in the case of the involuntary abandonment of stranded or damaged fishing nets, also known as “ghost nets”. In this study, the global scientific literature on coralligenous habitat was explored, with a particular focus on human impacts and fishing activities. The analysis was carried out using the VOSviewer software, generating network maps based on literature data retrieved from the Scopus database. The results show that the scientific literature is mainly concentrated in Italy, proving the important contribution provided by the Italian research on the topic. The results also highlight a research gap in the application of environmental accounting methods to quantify and value natural capital and ecosystem services associated to the coralligenous habitat, and their loss due to human impacts.

Coralligenous bioconstructions are a key Mediterranean ecosystem for their associated biodiversity and role in the blue carbon cycle. They are also sensitive to environmental alterations (e.g., climate change) and other anthropic impacts related to coastal anthropization (e.g., fishing activities). Marine-coastal zone protection, conservation programs and management strategies are essential to guarantee a good ecological status of the coralligenous habitat. In this context, environmental and ecosystem accounting are useful tools to measure natural capital stocks and ecosystem service flows associated with marine ecosystems, conveying their importance in scientific and policy contexts. Indeed, the importance of marine ecosystems is often overlooked due to the difficulty of expressing their value in common units, making it challenging for decision-makers to explore trade-offs between conservation and exploitation of marine ecosystems. In this study, a biophysical and trophodynamic environmental accounting model was used to assess the biophysical value of natural capital stocks of the coralligenous habitat in three Marine Protected Areas (MPAs) of the Campania Region (Southern Italy): Punta Campanella, Santa Maria di Castellabate, and Costa degli Infreschi e della Masseta. The natural capital value per unit area associated with the coralligenous habitat ranged from 2.44 × 10¹² to 4.72 × 10¹² sej m⁻² for Santa Maria di Castellabate and Punta Campanella, respectively. Despite the different intensive values of natural capital calculated for the MPAs, there were no significant differences both in the biomass values of the taxonomic groups and in the biomass-based Shannon diversity index. Additionally, the biophysical values were also converted into monetary units, with the aim of facilitating the understanding of the importance of natural stocks in socio-economic and political contexts. The economic equivalent of natural capital value refers to the total extent of the coralligenous habitat and ranged from about EUR 1 to 15 million for Costa degli Infreschi e della Masseta and Santa Maria di Castellabate, respectively. The results of this study could be useful for local managers and policy makers and may make them more likely to achieve biodiversity conservation and sustainable development goals in MPAs. This is the first study devoted to the assessment of natural capital value of coralligenous habitats. Future studies could complement the results of this study with biophysical and economic assessments of ecosystem service flows generated by coralligenous habitats, focusing on the role they play in human well-being.

Air quality improvement represents a critical challenge for the European Union, with particulate matter (PM) being the most harmful pollutant in urban areas. Urban Green Infrastructures (UGIs) provide essential ecosystem services that mitigate air pollution, notably through PM₁₀ removal via deposition on leaf surfaces, reducing health risks associated with poor air quality. This study quantifies the PM₁₀ removal supplied by urban forests in the Bydgoszcz–Toruń area (Poland) using a spatially explicit modeling framework. Remotely sensed Leaf Area Index, vegetation cover, and PM₁₀ concentration data were integrated within a GIS environment, with all analyses conducted on a seasonal basis to capture temporal variability in vegetation phenology and pollutant levels. Resulting maps of mean seasonal PM₁₀ removal efficiency (kg/ha) reveal distinct functional group patterns: deciduous broadleaves reach peak efficiency in summer, whereas conifers provide a more consistent year-round contribution, resulting in the highest annual removal. Monetary valuation was performed using externality costs from the European Environmental Agency. Overall, urban forests remove 3360.40 Mg of PM₁₀ annually, corresponding to an estimated value of 255.69 M€. Integrating biophysical and economic perspectives supports urban planning and highlights UGIs as nature-based solutions to enhance air quality, protect public health and promote ecosystem biodiversity and resilience.