Marine ecosystems are open, complex, adaptive, and hierarchical systems highly integrated through the exchange of matter and energy flows. This flows exchange allows marine ecosystems to operate at different scales acting as dissipative structures, building natural capital stocks capable of generating several ecosystem services vital for human well-being. Humans derive a wide range of goods and services from marine ecosystems while, at the same time, generate several impacts causing biodiversity loss and seriously affecting their capacity to provide benefits to humans. Effective management strategies are crucial to conserve healthy and diverse marine and coastal ecosystems, maintain the valuable functions and services they provide, and allow for sustainable human activities. In recent years, Marine Protected Areas (MPAs) have been increasingly acknowledged worldwide as important tools to conserve biodiversity and achieve human well-being and sustainable development goals. Assessing the value of natural capital and ecosystem services is crucial to raise awareness on their importance, support conservation strategies, and ensure the sustainable management of marine ecosystems. This study aimed at calculating biomass and emergy-based indicators to assess the value of natural capital stocks in a Mediterranean MPA. The assessment was performed through a biophysical and trophodynamic environmental accounting model fed with field biomass data collected through ad hoc sampling campaigns performed in the MPA. Four main macro-habitats were investigated: sciaphilic hard bottom (coralligenous bioconstructions), photophilic hard bottom, soft bottom, and Posidonia oceanica seagrass beds. The biomass density of the main autotrophic and heterotrophic taxonomic groups identified in the four macro-habitats of the MPA was evaluated. Based on this biomass matrix, the emergy value of natural capital stocks was assessed. The Posidonia oceanica seagrass beds habitat showed the highest biophysical value (2.32·10¹⁹ sej) at MPA scale, while coralligenous bioconstructions resulted the habitat with the highest biophysical value per unit area (2.72·10¹² sej m⁻²). In addition, to complement the biophysical assessment with an economic perspective, the emergy-based indicators were converted into monetary units. The total value of natural capital of the whole MPA resulted in about 46 M€. The results of this study can support local managers and policy makers in the development of management strategies to ensure nature conservation and sustainable human activities. They can be also used as a benchmark for the assessment of natural capital value at larger scales in support of a proper consideration and inclusion of nature value into processes of policy making.

海洋生态系统是开放的，复杂的，自适应的和分级的系统，通过物质和能量流的交换而高度集成。这种流量交换使海洋生态系统可以作为耗散结构在不同规模上运作，建立了自然资本存量，能够产生对人类福祉至关重要的多种生态系统服务。人类从海洋生态系统中获得各种各样的商品和服务，与此同时，产生了多种影响，导致生物多样性丧失，并严重影响了其为人类提供利益的能力。有效的管理策略对于保护健康多样的海洋和沿海生态系统，维持其提供的宝贵功能和服务以及实现可持续的人类活动至关重要。最近几年，海洋保护区（MPA）在世界范围内已被公认为是保护生物多样性，实现人类福祉和可持续发展目标的重要工具。评估自然资本和生态系统服务的价值对于提高人们对其重要性的认识，支持保护战略并确保海洋生态系统的可持续管理至关重要。这项研究旨在计算基于生物量和能值的指标，以评估地中海MPA中自然资本存量的价值。通过生物物理和营养动力学环境核算模型进行评估，该模型采用通过收集的田间生物量数据 评估自然资本和生态系统服务的价值对于提高人们对其重要性的认识，支持保护战略并确保海洋生态系统的可持续管理至关重要。这项研究旨在计算基于生物量和能值的指标，以评估地中海MPA中自然资本存量的价值。通过生物物理和营养动力学环境核算模型进行评估，该模型采用通过收集的田间生物量数据 评估自然资本和生态系统服务的价值对于提高人们对其重要性的认识，支持保护战略并确保海洋生态系统的可持续管理至关重要。这项研究旨在计算基于生物量和能值的指标，以评估地中海MPA中自然资本存量的价值。通过生物物理和营养动力学环境核算模型进行评估，该模型采用通过收集的田间生物量数据在MPA中进行的临时抽样活动。研究了四个主要的宏观栖息地：坐骨神经性硬底（珊瑚生物构造），亲光性硬底，软底和波西多尼亚大洋洲海草床。评价了在MPA的四个宏观栖息地中确定的主要自养和异养生物分类组的生物量密度。基于该生物量矩阵，评估了自然资本存量的能值。的Posidonia大洋洲海草床栖息地显示了最高的生物物理值（2.32·10 ¹⁹在MPA规模SEJ），而coralligenous bioconstructions导致每单位面积（2.72·10的最高生物物理值的栖息地¹² SEJ米^-2）。此外，为了从经济角度补充生物物理评估，将基于能值的指标转换为货币单位。整个MPA的自然资本总价值约为4,600万欧元。这项研究的结果可以支持地方管理人员和政策制定者制定管理策略，以确保自然保护和可持续的人类活动。它们还可以用作大规模评估自然资本价值的基准，以支持对自然价值的适当考虑并将自然价值纳入决策过程。