• Energy Research

Although regional studies and projections suggest the deterioration of estuaries as a consequence of climate change, it is still difficult to fully understand the importance of such changes in estuarine systems. This limitation is particularly important considering their high dynamism and the lack of temporally extended in situ databases with a good spatial coverage for these systems worldwide. Furthermore, contradictory patterns have been observed across the globe. Motivated by these issues, in this study we question the availability of in situ observational evidence of climate change in estuarine systems through a detailed meta-analysis of existing publications. A topic-related search considering the outputs of the Web of Science library was conducted in order to obtain a characterization of the existing studies on climate change in estuarine systems. Results confirmed that climate change has increasingly been studied since 2000 and that marine climate change constituted the focus of 9.69 % of those studies. From these, only 9.30 % encompassed estuarine studies and just 1.13 % used in situ observations from estuarine systems (i.e., 0.11 % of the total climate change publications). Reanalysis products were the most used tools to assess changes in estuarine systems and sea temperature was the most analyzed variable. These results highlight the need to further address such questions using in situ observational data and to implement long-term observatories to fully identify evidence of climate change in estuarine systems, supporting modelling approaches and promoting the development of effective mitigation plans.

Wind energy resources are subject to changes in climate, so the use of wind energy density projections in the near future is essential to determine the viability and profitability of wind farms at particular locations. Thus, a step forward in determining the economic assessment of floating offshore wind farms was taken by considering current and near-future wind energy resources in assessing the main parameters that determine the economic viability (net present value, internal rate of return, and levelized cost of energy) of wind farms. This study was carried out along the Atlantic coast from Brest to Cape St. Vincent. Results show that the future reduction in wind energy density (2%–6%) mainly affects the net present value (NPV) of the farm and has little influence on the levelized cost of energy (LCOE). This study provides a good estimate of the economic viability of OWFs (Offshore Wind Farms) by taking into account how wind resources can vary due to climate change over the lifetime of the farm.

The Minho and Lima estuaries, separated by approximately 20 km, are two important transitional systems from the NW Atlantic Portuguese coast. Considering their contrasting characteristics, the present work aims to investigate climate change impacts in salt intrusion and estuarine plumes interaction, through an integrated hydrological characterization. The three-dimensional numerical model Delft3D was implemented to explore the hydrological response of these two systems taking into account their interaction. The model was applied to investigate two different climate change scenarios (RCP 4.5 and RCP 8.5), where physical variables such as sea level and river outflow were varied following summer and winter conditions. The numerical results revealed typically estuarine hydrological patterns, although some different features were found for each estuary. The head and mouth of the estuaries may be the zones most affected by climate change. In the first zone, the salinity may increase in the future in response to freshwater reduction from the Minho and Lima rivers. Considering the cumulative impact of the sea level rise, the saline intrusion may increase in the future: in the Minho estuary it reaches 14 km for the Present scenario during the dry season, penetrating further under climate change conditions (15 km for the RCP 4.5 scenario, and 17 km for the RCP 8.5 scenario); in the Lima estuary, the salt propagates further inland, reaching 17 km for the Present scenario, 18 km for the RCP 4.5 scenario, and a maximum of 20 km for the RCP 8.5 scenario. In all scenarios, during winter conditions, the estuarine plumes are larger and wider, being predicted that in the future they will reduce their dimensions during the winter period, and remain unchanged during summertime. Concisely, this modelling study provided more expertise about the physical patterns of these two estuaries and their interaction, as well as to anticipate the climate change impacts in their dynamics.

The common cockle Cerastoderma edule is a widespread bivalve species inhabiting estuarine systems across the North East Atlantic, where it provides several ecosystem services, and represents a valuable fishery resource for local economies. However, anthropogenic pressure and more frequent extreme weather events threaten the resilience of the species. Spatially explicit information on species distribution is critical for the implementation of management and conservation practices. This study assessed the potential distribution of C. edule in the Ria de Aveiro by estimating the habitat suitability using an ensemble approach based on ecological niche modeling and recently developed hydrodynamic and water quality models to forecast both average and projected estuarine conditions. The models were developed for the summer of 2013 and spring of 2019 and potential range shifts in the species distribution were forecasted under projected environmental conditions: high and low estimates of freshwater discharge, a 2 degrees C increase in water temperature, and the combined effect of low freshwater discharge and increased water temperature. The results suggest that salinity, time of submersion, and current velocity play an important role in the distribution of cockles, and large areas were consistently classified with high habitat suitability. Increased freshwater discharge (both seasons) and low discharge coupled to increased temperature (spring) resulted in large decreases in suitable habitat. Conversely, low freshwater discharges and average (unchanged) temperatures increased the suitable habitat in the outermost regions of the Ria. The spatially explicit information provided contributes to a better understanding of the vulnerability of C. edule in the Ria de Aveiro to extreme weather events (e.g., droughts, river floods) and may support adaptive management strategies of the cockle fishery during these conditions. Moreover, this approach can be transferred to other estuarine ecosystems for which data describing the environmental conditions (e.g., derived from numerical models), and information about species presence are available (including data-poor species). LA/P/0094/2020 POCI-01-0145-FEDER-028425 info:eu-repo/semantics/publishedVersion

Abstract Wave energy is poised to thrive as a renewable energy provider. Present and future wave energy resource for the northwest Iberian Peninsula coast is classified by means of a dynamical downscaling performed with the SWAN model of WAVEWATCH III simulations driven by historical wind data and future wind under the RCP8.5 greenhouse gas emission scenario. The wave energy resource classification was performed applying a Delphi method to seven indices, related to wave resource, stability, risk and installation and maintenance costs (mean wave power energy, temporal and monthly variability, downtime, risk, water depth and distance to the coast). In general, conditions for the exploitation of wave energy will worsen by the end of the century due to the decrease in wave energy's mean value and an increase in energy variability. Furthermore, the risk factor will also worsen due to the increase in the frequency of extreme ocean waves. Despite this, the wave energy resource will be classified as excellent along the west coast of the Iberian Peninsula and as good along the Bay of Biscay's coast by the end of the century. Only in the northwest corner of the Iberian Peninsula, the wave resource will be classified as outstanding.

Climate change and global sea-level rise are major issues of the 21st century. The main goal of this study is to assess the physical and biogeochemical status of the Ria de Aveiro lagoon (Portugal) under future climate scenarios, using a coupled physical/ eutrophication model. The impact on the lagoon ecosystem status of the mean sea level rise (MSLR), the amplitude rise of the M2 tidal constituent (M2R), the changes in the river discharge, and the rising of the air temperature was investigated. Under MSLR and M2R, the results point to an overall salinity increase and water temperature decrease, revealing ocean water dominance. The main lagoon areas presented salinity values close to those of the ocean waters (~34 PSU), while a high range of salinity was presented for the river and the far end areas (20–34 PSU). The water temperature showed a decrease of approximately 0.5–1.5 °C. The responses of the biogeochemical variables reflect the increase of the oceanic inflow (transparent and nutrient-poor water) or the reduction of the river flows (nutrient-rich waters). The results evidenced, under the scenarios, an overall decreasing of the inorganic nitrogen concentration and the carbon phytoplankton concentrations. A warm climate, although increasing the water temperature, does not seem to affect the lagoon’s main status, at least in the frame of the model used in the study.

A large number of estuarine systems provide favorable conditions for aquaculture, including high nutrient content, sheltered waters, and favorable water temperatures. In this context, the main objective of this work is to identify the most suitable areas within the Ria de Alvor for bivalve and fish aquaculture production considering present and future conditions in a climate change context. A suitability index was developed based on the results of an annual simulation with the Delft3D model and the thresholds and optimal values of development of each species were analyzed. Generally, results suggest that the most suitable areas for aquaculture were located along the axis of the lagoon’s main channel, although seasonal variability was presented depending on the species. During winter and autumn, bivalves (oysters and mussels) are more susceptible to environmental conditions than fish. Conversely, spring presents the most favorable environmental conditions for the production of all species considered. Future projections indicate a general decrease in aquaculture suitability, particularly during winter for both bivalve species and during summer for Mussels, mostly due to the predicted increase in water temperature.