Metodologías aplicables a la ordenación del espacio marítimo en el ámbito del desarrollo actual y futuro de las energías renovables y la acuicultura

Abstract

Marine and coastal zones are currently under pressure due to an increasing demand for areas to develop different activities. This is the case of the renewable energy and aquaculture sectors, which are expanding offshore as a consequence of both energy and food demands for a growing world population and the possible surpassing of the carrying capacity of coastal and land-based systems. Therefore, the short to long-term progression of these marine sectors will require the adoption of integrated planning and management approaches, where competitive and synergistic interactions with the socio-ecological environment must be analyzed on an appropriate scale. However, marine renewable energy and offshore aquaculture sectors rely greatly on met-ocean and environmental conditions. Thus, the effects of climate change must be considered in the planning process of these activities. In this context, the general objective of this thesis was to develop and apply methodologies to recognize potential zones for the development of marine wind and wave energy production and offshore aquaculture, with the ultimate goal of promoting the sustainable development of these activities in the context of a marine spatial planning strategy. The major goal was developed through four different specific objectives: i) global assessment of renewable energy potential; ii) global assessment of opportunities for offshore aquaculture; iii) regional assessment of the co-location opportunities for renewable energy and aquaculture activities; iv) gegional assessment of the possible effects of climate change on the renewable energy and aquaculture sectors. First, a global assessment of the potentialities and opportunities for the development of offshore marine renewable energy and aquaculture sectors was carried out. For this purpose, methodological approaches were developed and applied to identify potential zones for the exploitation of wind and wave energy and for the farming of marine fish species. For the first specific objective, a comprehensive analysis of the global potential of offshore resources was carried out considering the availability of energy resources, the structural survivability of energy conversion devices, logistics activities, and distances from consumer centers. The results allowed to recognize potential zones for the implementation of wind and wave energy activities in the short and mid-term, as well as zones for the combined exploitation of these activities. Regarding the wind energy sector, the zones identified as favorable for exploitation coincided with the offshore areas with the highest energy production in operation (e.g. the North Sea, the United States and China) and areas still under development (e.g. Greece, Japan and South Korea). On the other hand, zones that have not yet been exploited were also identified, opening opportunities for the wind and wave energy sector to grow, such as in the exclusive economic zone (EEZ) of Argentina, Chile, Colombia, Morocco and Peru. For aquaculture, the global assessment was based on the analysis of the biological conditions for the farming of seven fish species, met-ocean conditions to house offshore cages, and suitable conditions for operation and maintenance (O&M) activities (specific objective No. 2). Opportunities for the development of this industry were identified in unexploited zones, such as farming of meagre, gilthead seabream and European seabass to the west and east of South America. The potential zones identified also coincided with regions of remarkable aquaculture production for these species (e.g. Norway, Chile and the United Kingdom for the Atlantic salmon). The main potential zones identified for fish farming were concentrated in South America (South Pacific and South Atlantic oceans), Africa (Northern Atlantic Ocean), the Mediterranean, Japanese and Chinese seas, and Oceania. After the identification of potential zones for the exploitation of marine renewable energies and offshore aquaculture on a global scale, a more detailed study at a regional scale was carried out. This investigation sought to assess the offshore potential to develop these industries and to characterize the spatial synergies for the co-location of these three activities (specific objective No. 3). A multi-criteria approach based on independent probabilistic suitability and mapping analysis was applied to a case study in the Canary Archipelago for: i) wind and wave energy production potential; ii) structural requirements for energy devices and aquaculture cages; iii) limits for O&M activities; iv) feasibility to transport energy to the grid; and v) biological requirements for eight species of fish. Opportunities for the co-location of wind and aquaculture farms were identified in the southeastern portion of the islands, while opportunities for combining wind and wave energy were found mainly in the islands of Tenerife and Fuerteventura. Finally, to analyze the possible effects of climate change on these marine economies in Europe, the distribution of favorable conditions for the exploitation of wind energy, wave energy and aquaculture were analyzed considering two scenarios (specific objective No. 4). Wind and wave energy resources and environmental conditions for fish farming were evaluated based on a current scenario (reference climate) and another scenario towards the end of the 21st century (projected climate). The delta change method was considered for projections, using the General Circulation Models outputs (Representative Concentration Pathway 8.5) from the fifth phase of the Coupled Model Intercomparison Project. The results obtained showed that the observed climate changes will not have direct impacts on the geographical distribution of the potential zones for the energy industry (both wind and wave energy), that is, they do not seem to pose a real threat to this industry. For the aquaculture sector, a considerable change in environmental conditions was projected, requiring adaptation of this sector in relation to the geographical location of fish farms. Thus, strategic planning should be considered to reduce unfavorable conditions to areas with activities in operation and to maximize the opportunities generated by climate change. Therefore, the global analysis for marine renewable energy and offshore aquaculture provides guidelines to assist the development of these sectors, supporting the management of marine spaces. The identification of spatial synergies between these activities reflects the opportunities of combining different uses to promote a sustainable growth of the blue economy, reducing potential conflicts and optimizing the use of marine space. In addition, the assessment of potential zones for these activities, considering the possible effects of climate change, represents a useful stepping-stone for improving decision-making and assisting in the management of marine economies. In summary, the results of this thesis provide information and tools to assist in the integrated management and strategic planning of offshore wind energy, wave energy and aquaculture sectors, supporting specific strategies to optimize the use of space for sustainable exploitation of the marine environment, adaptive management in the face of climate change, and fostering the coexistence of uses to avoid conflicts and highlight synergies between these activities. Consequently, the contribution of this thesis is directly linked to the development of these emerging marine economies from a Blue Growth perspective.