• Energy Research

Global ocean warming, wave extreme events, and accelerating sea-level rise are challenges that coastal communities must address to anticipate damages in coming decades. The objective of this study is to undertake a time-series analysis of climate change (CC) indicators within the Bay of Biscay, including the Basque coast. We used an integrated and flexible methodology, based on Generalized Additive Mixed Models, to detect trends on 19 indicators (including marine physics, chemistry, atmosphere, hydrology, geomorphology, biodiversity, and commercial species). The results of 87 long-term time series analysed (~512,000 observations), in the last four decades, indicate four groups of climate regime shifts: 1) A gradual shift associated with CC starting in the 1980s, with a warming of the sea surface down to 100 m depth in the bay (0.10-0.25 °C per decade), increase in air temperature and insolation. This warming may have impacted on benthic community redistribution in the Basque coast, favouring warm-water species relative to cold-water species. Weight at age for anchovy and sardine decreased in the last two decades. 2) Deepening of the winter mixed layer depth in the south-eastern bay that probably led to increases in nutrients, surface oxygen, and chlorophyll concentration. Current increases on chlorophyll and zooplankton (i.e., copepods) biomass are contrary to those expected under CC scenarios in the region. 3) Sea-level rise (1.5-3.5 cm per decade since 1990s), associated with CC. 4) Increase of extreme wave height events of 16.8 cm per decade in the south-eastern bay, probably related to stormy conditions in the last decade, with impacts on beach erosion. Estimating accurate rates of sea warming, sea-level rise, extreme events, and foreseeing the future pathways of marine productivity, are key to define the best adaptation measures to minimize negative CC impacts in the region.

Rising global sea level increases the vulnerability of coastal regions to storm surge flooding. The impact of extreme high waters resulting from the combination of tidal oscillations and changes in mean sea level and in storm surges during the 21st century has been explored in the Bizkaian coast (northern Spain). Mean sea level variations due to temperature changes were estimated from an ensemble mean of global atmosphere-ocean general circulation models in the Bay of Biscay under A1B and A2 climate change scenarios. Changes in the frequency and intensity of storm surges were obtained from the output of a barotropic regional ocean model forced by greenhouse gas concentrations during 2000−2100. The storm surge model was calibrated using available tide gauge observations. Based on the above estimations, return levels of total sea level extremes are expected to increase by up to 40 cm with respect to present-day values. The likely impacts of resulting floods on coastal and estuarine habitats of the Bizkaian coast were assessed applying the return levels to a high precision light detection and ranging (LiDAR) based Digital Terrain Model. Results show that during the second half of the 21st century up to 202 ha are under risk of flooding, of which 50% correspond to urbanized land including industrial and residential areas. This represents a more than 3-fold increase compared to the area at risk from present sea level extremes. This study provides insight into both regional sea level variability and local floodrisks, and thus provides inputs for the formulation of effective mid-term adaptation measures to sea level extremes. This project has been supported by the Department of Environment and Regional Planning and by the Industry, Trade and Tourism Department of the Basque Government (K-Egokitzen II project, Etortek Funding Program) and the projects VANIMEDAT-2 (CTM2009-10163- C02-01, funded by the Spanish Marine Science and Technology Program and the E-Plan of the Spanish Government) and ESCENARIOS (funded by the Agencia Estatal de METeorología). G.J. acknowledges a ‘JAE-DOC’ contract funded by the Spanish Research Council (CSIC). M.M. acknowledges a ‘Ramon y Cajal’ contract funded by the Spanish Ministry of Science. The authors acknowledge the contribution of R. Moncho for valuable technical support with LiDAR data processing. Peer reviewed

To effectively future-proof the management of the European Union fishing fleets we have explored a suite of case studies encompassing the northeast and tropical Atlantic, the Mediterranean, Baltic and Black Seas. This study shows that European Union (EU) fisheries are likely resilient to climate-driven short-term stresses, but may be negatively impacted by long-term trends in climate change. However, fisheries’ long-term stock resilience can be improved (and therefore be more resilient to increasing changes in climate) by adopting robust and adaptive fisheries management, provided such measures are based on sound scientific advice which includes uncertainty. Such management requires regular updates of biological reference points. Such updates will delineate safe biological limits for exploitation, providing both high long-term yields with reduced risk of stock collapse when affected by short-term stresses, and enhanced compliance with advice to avoid higher than intended fishing mortality. However, high resilience of the exploited ecosystem does not necessarily lead to the resilience of the economy of EU fisheries from suffering shocks associated with reduced yields, neither to a reduced carbon footprint if fuel use increases from lower stock abundances. Fuel consumption is impacted by stock development, but also by changes in vessel and gear technologies, as well as fishing techniques. In this respect, energy-efficient fishing technologies already exist within the EU, though implementing them would require improving the uptake of innovations and demonstrating to stakeholders the potential for both reduced fuel costs and increased catch rates. A transition towards reducing fuel consumption and costs would need to be supported by the setup of EU regulatory instruments. Overall, to effectively manage EU fisheries within a changing climate, flexible, adaptive, well-informed and well-enforced management is needed, with incentives provided for innovations and ocean literacy to cope with the changing conditions, while also reducing the dependency of the capture fishing industry on fossil fuels. To support such management, we provide 10 lessons to characterize ‘win-win’ fishing strategies for the European Union, which develop leverages in which fishing effort deployed corresponds to Maximum Sustainable Yield targets and Common Fisheries Policy minimal effects objectives. In these strategies, higher catch is obtained in the long run, less fuel is spent to attain the catch, and the fisheries have a higher resistance and resilience to shock and long-term factors to face climate-induced stresses.

Incorrect Affiliation In the published article, there was an error regarding the affiliation for Jasper Van Vlasselaer. Instead of: 13 Spanish Institute of Oceanography (IEO-CSIC) (Palma), Ecosystem Oceanography Group (GRECO), Palma de Mallorca, Spain, he should have: 11 Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Fisheries and Aquatic Production, Oostende, Belgium. In the published article, there was an error regarding the affiliation for Luc Van Hoof. Instead of: 14 Department of Marine Sciences, University of the Aegean, Mytilene, Greece he should have 3 Wageningen Marine Research, Wageningen University and Research, Ijmuiden, Netherlands The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.

27 páginas, 13 figuras, 3 tablas. Artículo Open Access. The impacts of global climate change on the Basque coast and the pelagic systems within the southeastern Bay of Biscay are reviewed. Climate projections under greenhouse gas emission scenarios indicate that this area will experience changes in climate throughout the 21st century, including warming of surface air (especially heat wave episodes), intensification of extreme daily rainfall (10%), warming of the upper 100 m of the ocean layer (1.5 to 2.05°C), and sea level rise (SLR; 29 to 49 cm). Observations made in the bay throughout the 20th century for air temperature and mean sea level are in agreement with these projections. Trends in ocean-climatic historical observations within the area, including sea temperature, precipitation, upwelling/downwelling, turbulence and wave climate, are also reviewed. The main impacts on the coast are expected to be from SLR, especially in low-lying areas (mostly urbanised) within estuaries. Sandy beaches are also expected to undergo significant mean shoreline retreats of between 25 and 40% of their width. As the sea level rises, the natural migration of saltmarshes and intertidal seagrasses landward will be constrained, in most cases, by existing anthropogenic fixed boundaries. Empirical relationships between the distribution and dynamics of the long-term biological measures (plankton, primary production, benthos, and fisheries) on the one hand, and ocean-climatic variability on the other, indicate that pelagic and coastal water ecosystems will be affected by ocean warming, increased stratification, shifts in anomaly patterns and streamflow regimes. The largest uncertainties are associated with the lack of down-scaled projections within the bay on ocean circulation, ocean-meteorological indices, wave climate and ocean acidification. Este estudio ha sido financiado por el Departamento de Medio Ambiente, Planificación Territorial, Agricultura y Pesca del Gobierno Vasco (Proyectos K-Egokitzen y EKLIMA21 , del Programa Etortek); así como por el Ministerio de Medio Ambiente y Medio Rural y Marino del Gobierno de España (Proyecto Ref.: 0.39/ SGTB/ 2007/4.1), y el Ministerio de Ciencia e Innovación(Proyecto Ref.: CGL2008-03321). Peer reviewed