• Energy Research

Ypacaraí Lake is the most renowned lake in landlocked Paraguay and a major source of drinking and irrigation water for neighbouring towns. Beyond its socioeconomic and cultural significance, it has great ecological importance, supporting a rich biodiversity. Rapid growth of human presence and activities within its basin has led to its environmental degradation, a heartfelt matter of high political concern that compels intervention. Here, by reconstructing the history of scientific and management-oriented research on this system, we provide a comprehensive assessment of current knowledge and practice to which we contribute our recent, novel findings. An upward trend in total phosphorus concentration confirms ongoing eutrophication of an already eutrophic system, evidenced by consistently high values of trophic state indices. Downward trends in water transparency and chlorophyll-a concentration support the hypothesis that primary production in this lake is fundamentally light limited. Statistical and other analyses suggest high sensitivity of the system to hydraulic, hydro-morphological and hydro-meteorological alterations arising, respectively, from engineering interventions, land use and climate change. By discussing knowledge gaps, opportunities for research and challenges for management and restoration, we argue that this case is of high scientific value and that its study can advance theoretical understanding of shallow subtropical lakes.

European seas are experiencing rapid development. The anthropogenic demand for marine resources and space exerts the need for novel concepts for sustainable resource exploitation and smart space allocation. Multi-Use (MU) is an emerging concept to overcome spatial claims and support Blue Growth, however its actual potentials and current status of implementation in different sea basins is to a large extent unexplored. An analytical framework using a mixed method approach is proposed for the identification and analysis of MU potentialities in eight EU countries of the Euro-Mediterranean sea basin. The paper addresses opportunities and challenges of ten existing and potential MU combinations driven by three maritime sectors: tourism, renewable energy and Oil & Gas industry. Opportunities and challenges for MU development were presented in terms of drivers, added values, barriers and impacts. Results show that highest potential for MU development are related to tourism-driven MU combinations (e.g. pescatourism), but also emerging MU potentials exist related to Floating Offshore Wind energy and aquaculture (Gulf of Lion) and the re-use of Oil & Gas decommissioned platforms (Northern-Central Adriatic Sea). Findings were discussed for their geospatial distribution and their policy, socio-economic, technical and environmental boundary conditions. Recommendations on actions to foster MU development in the Euro-Mediterranean sea space are provided.

The concept of multi-use of the sea has increased popularity in the last decades with ocean space getting increasingly crowded due to the development of maritime economy. The concept of multi-use is based on the idea that competing claims for space can be a source of conflicts but may also lead to mutual benefits for the different users when smart combinations are sought. Despite increasing European-wide efforts, on-the-ground knowledge and practice on multi-use are still limited. With the aim to investigate opportunities for multi-use development in the European seas, ten case studies were selected from different site-specific contexts. This paper analyses characteristics and potential of ocean multi-use development by integrating outcomes from desk analysis and perceptions of stakeholders from different action arenas in each of the study areas. Commonalities and contrasts amongst different combinations of sea uses and cases are discussed. The results show a high heterogeneity of multi-uses opportunities across the cases, with many different combinations identified. The examined cases shared an overall balance between factors promoting (drivers) and hindering (barriers) multi-use development /strengthening, and the prevalence in stakeholders’ opinion of expected benefits (added values) of multi-use implementation on its possible negative impacts. Actions required at local, regional (sub-national), and national levels to further exploit the potential of multi-use are proposed. This is a preprint of a paper submitted to the journal PLOS ONE. The final accepted paper is published as: Bocci M, Sangiuliano SJ, Sarretta A, Ansong JO, Buchanan B, Kafas A, Caña-Varona M, Onyango V, Papaioannou E, Ramieri E, Schultz-Zehden A, Schupp MF, Vassilopoulou V, Vergílio M. 2019. Multi-use of the sea: A wide array of opportunities from site-specific cases across Europe. PLOS ONE 14:e0215010. DOI: 10.1371/journal.pone.0215010.

The “open ocean” has become a highly contested space as coastal populations and maritime uses soared in abundance and intensity over the last decades. Changing marine utilization patterns represent a considerable challenge to society and governments. Maritime spatial planning has emerged as one tool to manage conflicts between users and achieve societal goals for the use of marine space; however, single-sector management approaches are too often still the norm. The last decades have seen the rise of a new ocean use concept: the joint “multi-use” of ocean space. This paper aims to explain and refine the concept of ocean multi-use of space by reviewing the development and state of the art of multi-use in Europe and presenting a clear definition and a comprehensive typology for existing multi-use combinations. It builds on the connectivity of uses and users in spatial, temporal, provisional, and functional dimensions as the underlying key characteristic of multi-use dimensions. Combinations of these dimensions yield four distinct types of multi-use with little overlap between them. The diversity of types demonstrates that there is no one-size-fits-all management approach, but rather that adaptive management plans are needed, focusing on achieving the highest societal benefit while minimizing conflicts. This work will help to sharpen, refine and advance the public and academic discourse over marine spatial planning by offering a common framework to planners, researchers and users alike, when discussing multi-use and its management implications.