Recognizing the urgent need for sustainability, we argue that to move beyond the rhetoric and to actually realize sustainable development, it must be considered as a decision-making strategy. We demonstrate that sustainability assessment and sustainability indicators can be powerful decision-supporting tools that foster sustainable development by addressing three sustainability decision-making challenges: interpretation, information-structuring, and influence. Particularly, since the 1990s many substantial and often promising sustainability assessment and sustainability indicators efforts are made. However, better practices and a broader shared understanding are still required. We aim to contribute to that objective by adopting a theoretical perspective that frames SA and SI in the context of sustainable development as a decision-making strategy and that introduces both fields along several essential aspects in a structured and comparable manner.

Summary: Many areas of science, including conservation and environmental management, regularly require engaging stakeholders or experts to produce consensus or technical inputs. The Delphi technique is an iterative and anonymous participatory method used for gathering and evaluating such expert‐based knowledge. We outline the methodology of the Delphi technique and provide a taxonomy of its main variants. In addition, we refine the technique by providing suggestions to address common limitations (e.g. time consumption, attrition rate) in order to make the method more suitable for application in ecology and conservation. A comprehensive search for studies that have applied the Delphi technique in conservation and environmental management resulted in 36 papers. The Delphi technique has been applied to a range of issues, including developing decision support systems and predicting ecological impacts of climate change. The papers reviewed suggest that the Delphi technique is an efficient, inclusive, systematic and structured approach that can be used to address complex issues. A major strength compared to other group‐based techniques is the reduced influence of social pressures among respondents. The Delphi technique is relatively little used and seems undervalued. Given its wide range of possible applications, it could be applied more widely in evaluating evidence and providing expert judgments.

At the turn of the millennium, the world’s political leadership adopted sustainable development as a leading model for societal development. However, the terms “sustainable development”, “sustainability” and “sustainable” are sometimes over- and misused despite wide consensus about the concept’s meaning among sustainability scholars and practitioners. While the concept allows various sustainability views to co-exist, random conceptualizations which do not respect the fundamental sustainability principles undermine the concept’s objective to steer action. This lack of understanding of sustainability arguably inhibits its practical realization and a proper understanding of sustainability is urgently needed. In this paper we aim to contribute to a better understanding of sustainability by adopting a bird’s eye perspective. We review the rich contemporary literature, with a specific focus on the terminology, genesis, fundamental principles, mainstream views of sustainability, and several governing aspects. Further, using the evolving body of sustainability literature, the paper provides arguments to combat common misconceptions of sustainability.

The valuation of ecosystem services is a complex process as it includes several dimensions (ecological, socio-cultural and economic) and not all of these can be quantified in monetary units. The aim of this paper is to conduct an ecosystem services valuation study for mangroves ecosystems, the results of which can be used to inform governance and management of mangroves. We used an expert-based participatory approach (the Delphi technique) to identify, categorize and rank the various ecosystem services provided by mangrove ecosystems at a global scale. Subsequently we looked for evidence in the existing ecosystem services literature for monetary valuations of these ecosystem service categories throughout the biogeographic distribution of mangroves. We then compared the relative ranking of ecosystem service categories between the monetary valuations and the expert based analysis. The experts identified 16 ecosystem service categories, six of which are not adequately represented in the literature. There was no significant correlation between the expert based valuation (the Delphi technique) and the economic valuation, indicating that the scope of valuation of ecosystem services needs to be broadened. Acknowledging this diversity in different valuation approaches, and developing methodological frameworks that foster the pluralism of values in ecosystem services research, are crucial for maintaining the credibility of ecosystem services valuation. To conclude, we use the findings of our dual approach to valuation to make recommendations on how to assess and manage the ecosystem services provided by mangrove ecosystems.