O cambio climático

Os cambios no clima sucedéronse ao longo da historia do noso planeta debido a mecanismos naturais. Sen embargo, o cambio climático actual ten a singularidade de estar tamén afectado polo ser humano. Este efecto antropoxénico potencia o quecemento global, incrementando a velocidade dos cambios e limitando a capacidade de adaptación das especies ás novas condicións. Así, incluso variacións pequenas, como décimas de grao na temperatura, poden ser desfavorables para moitas especies, levando á extinción dalgunhas delas. O coñecemento dos cambios climáticos, tanto os pasados coma o actual, permite desenvolver ferramentas de mitigación e adaptación para enfrontarse aos cambios futuros do mellor xeito posible

Historical and future naturalization of Magallana gigas in the Galician coast in a context of climate change

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGMagallana gigas is a naturalized species on the north coast of Galicia (Rías Altas, Northwest Iberian Peninsula), where it was unintentionally introduced. In recent decades, a greater abundance of M. gigas has been observed on the Galician coast, expanding towards the south, reaching the Artabro Gulf (Rías Centrales, NW Galician coast), probably due to ocean warming. Although this species has been cultivated in the Rías Baixas since the early 1990s and spawning has been reported, recruitment was never observed, which is likely due to the cold water upwelled during the spawning months. The future rise in seawater temperature may favor the naturalization of the non-indigenous species M. gigas southwards, in the Rías Baixas. Thermally, the Ría de Arousa seems to be the most favorable estuary for the future settlement of M. gigas, which may occur in the next decades. The extent of thermally favorable zones within estuaries is projected to increase rapidly by mid-century, and reaching 100 % of the estuarine area by the end of the century. As has already happened in other areas of the world, the expansion and naturalization of the Pacific oyster on the Galician coast will likely affect the native communities and economic activities, making it necessary to implement monitoring and management strategies to mitigate its effect.Xunta de Galicia | Ref. ED481B-2021-103Xunta de Galicia-FEDER | Ref. ED431C 2021/44Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020Fundação para a Ciência e a Tecnologia | Ref. LA/ P/0094/202

Does global warming threaten small-scale bivalve fisheries in NW Spain?

Shellfisheries of the intertidal and shallow subtidal infaunal bivalves Ruditapes decussatus, Ruditapes philippinarum, Venerupis corrugata and Cerastoderma edule are of great socio-economic importance (in terms of landings) in Europe, specifically in the Galician Rías Baixas (NW Spain). However, ocean warming may threaten these fisheries by modifying the geographic distribution of the species and thus affecting productive areas. The present study analysed the impact of rising ocean temperature on the geographical distribution of the thermal comfort areas of these bivalves throughout the 21st century. The Delft3D model was used to downscale climate data from CORDEX and CMIP5 and was run for July and August in three future periods (2025–2049, 2050–2074 and 2075–2099) under the RCP8.5 scenario. The areas with optimal temperature conditions for shellfish harvesting located in the middle and outer parts of the rias may increase in the near future for R. decussatus, V. corrugata and C. edule and decrease in the far future for R. philippinarum. Moreover, shellfish beds located in the shallower areas of the inner parts of the Rías Baixas could be affected by increased water temperature, reducing the productive areas of the four species by the end of the century. The projected changes in thermal condition will probably lead to changes in shellfish harvesting modality (on foot or aboard vessels) with further socio-economic consequences.Xunta de Galicia | Ref. ED481B-2021-103Xunta de Galicia | Ref. ED431C 2021/44Xunta de Galicia | Ref. ED431C 2021/42Ministerio de Economía y Competitividad | Ref. CTM2014-51935-RFundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020Fundação para a Ciência e a Tecnologia | Ref. LA/P/0094/2020Financiado para publicación en acceso aberto: Universidade de Vigo/CISU

Hidrodinámica del NO de la Península Ibérica bajo condiciones climáticas pasadas y futuras

Characterization and monitoring of river plumes according to their main drivers (river discharge, wind and tide) is important to determine their impact on the adjacent coastal zone. The river discharge changes the thermohaline properties, causes changes in the currents circulation and transports suspended organic matter to coastal ocean water modifying its biogeochemical properties. Under certain circumstances: heavy rains and certain winds in platform, river inputs can penetrate into the nearby estuaries. Current technology allows plume satellite tracking (MODIS) through the analysis of the radiance. This technology has a resolution of up to 250 m, allowing to identify and characterize the river plumes, not only on the continental shelf, but also its possible intrusion into the outer and middle area and adjacent estuaries. This methodology will be used to characterize the Minho River plume and its possible intrusion into the Galician Rías Baixas. Synoptic river discharge, wind and tide conditions favourable to plume intrusion on the Rías will be characterized. After its correct identification, which is based on satellite data that covers only the near-surface meters, it is intended to complement the characterization with plume hydrodynamic simulation in the water column by numerical modelling.A caracterización e seguimento das plumas dos ríos en función dos forzamentos que as afectan (caudal, vento e marea) é de vital importancia para determinar o seu impacto na zona costeira adxacente. A descarga fluvial modifica as propiedades termohalinas, xera cambios na circulación das correntes e aporta materia en suspensión á auga oceánica costeira modificando a súas propiedades bioxeoquímicas. Baixo certas circunstancias: choivas intensas e determinados ventos na plataforma, os aportes fluviais poden penetrar en estuarios localizados nas súas proximidades. A tecnoloxía actual permite o seguimento por satélite (MODIS) da pluma a través da análise de radiancia. Esta tecnoloxía ten unha resolución de ata 250 m, permitindo identificar e caracterizar as plumas non unicamente na plataforma continental, senón tamén a súa posible intrusión na zona exterior e media dos estuarios adxacentes. Aplicarase esta metodoloxía para caracterizar a pluma do río Miño e a súa posible intrusión nas Rías Baixas Galegas. Caracterizaranse as condicións sinópticas de caudal, vento e marea que favorecen a intrusión da pluma do río nas rías. Tras a súa correcta identificación, a cal se fai mediante os datos de satélite e polo tanto só cubre os metros máis próximos á superficie, preténdese completar dita caracterización coa simulación hidrodinámica da pluma ó largo da columna de auga mediante o modelo numérico.La caracterización y seguimiento de las plumas de los ríos en función de los forzamientos que las afectan (caudal, viento y marea) es de vital importancia para determinar su impacto en la zona costera adyacente. La descarga fluvial modifica las propiedades termohalinas, genera cambios en la circulación de las corrientes y aporta materia en suspensión al agua oceánica costera modificando sus propiedades biogeoquímicas. Bajo ciertas circunstancias: lluvias intensas y determinados vientos en plataforma, los aportes fluviales pueden penetrar en estuarios localizados en sus proximidades. La tecnología actual permite el seguimiento satelital (MODIS) de la pluma a través del análisis de radiancia. Esta tecnología tiene una resolución de hasta 250 m, permitiendo identificar y caracterizar las plumas no únicamente en la plataforma continental, sino también su posible intrusión en la zona exterior y media de los estuarios adyacentes. Se aplicará esta metodología para caracterizar la pluma del río Miño y su posible intrusión en las Rías Baixas Gallegas. Se caracterizarán las condiciones sinópticas de caudal, viento y marea que favorecen la intrusión de la pluma del río en las rías. Tras su correcta identificación, la cual se hace a partir de los datos de satélite y por lo tanto solo cubre los metros más próximos a la superficie, se pretende completar dicha caracterización con la simulación hidrodinámica de la pluma a lo largo de la columna de agua mediante el modelo numérico

Modeling salinity drop in estuarine areas under extreme precipitation events within a context of climate change: effect on bivalve mortality in Galician Rías Baixas

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe mortality of infaunal bivalves (Venerupis corrugata, Cerastoderma edule, Ruditapes decussatus and Ruditapes philippinarum) due to a drop in salinity caused by extreme precipitation events in estuarine areas has been analyzed within a context of climate change. The Rías Baixas (NW Iberian Peninsula) were selected as a representative area of the estuarine environments where bivalve gathering is performed. Bivalve mortality under extreme precipitation events was analyzed both for historical (1990–2019) and future (2070–2099) periods. Precipitation data were retrieved from the Coordinated Regional Climate Downscaling Experiment (CORDEX) project under the Representative Concentration Pathway (RCP) 8.5 scenario and were converted into river discharges using the HEC-HMS hydrological model. The calculated river discharges were introduced into the Delft3D hydrodynamic model and simulations were performed in order to calculate transport conditions in the Rías Baixas. Salinity data were analyzed to estimate the mortality of the species due to salinity drops. In general, future conditions of moderate and severe mortality may be worse than historically observed, being more intense and covering larger areas. This is mainly observed under neap tides due to less dilution of freshwater plumes when compared with spring tides. Although all the Rías Baixas may be potentially affected, the impact will differ for each ria, being Arousa, where the highest discharges occur, the most affected. The differences among rias, especially those with a similar discharge pattern as Pontevedra and Vigo, suggest that bathymetric features also play a key role in the extent of the area affected by mortality.Xunta de Galicia | Ref. ED431C 2017/64Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/202

Análise de inundacións no xacemento arqueolóxico de Aquis Querquennis

O complexo arqueolóxico e termal Aquis Querquennis (Bande, Ourense) pódese cualificar como un dos máis importantes de Galicia e un importante centro de atracción turístico-cultural. Desde mediados do século xx, debido á construción do encoro das Conchas, o complexo vén sufrindo inundacións periódicas que afectan tanto a conservación coma a súa explotación turística. É, polo tanto, de especial interese estudar estas inundacións para coñecer o seu impacto e analizar posibles medidas para minimizar os seus efectos. Para isto realizouse un labor de recadación de datos hidrolóxicos e topográficos, que inclúe un traballo de fotogrametría por medio de imaxes aéreas tomadas por dron. Logo realizouse unha análise do alcance e da recorrencia das inundacións e observouse que o complexo ten sido afectado por eventos de longa duración. Tamén se realizou unha modelaxe numérica que permitiu a simulación de inundacións e o deseño de posibles barreiras de protección

Modelling the distribution of microplastics released by wastewater treatment plants in Ria de Vigo (NW Iberian Peninsula)

The accumulation of plastic waste in estuaries is growing due to the increase in their use in daily life and their inadequate treatment on wastewater plants (WWTPs). Hydrodynamic and particle-tracking models were validated and used to improve the knowledge about the distribution and concentration of microplastics released by WWTPs in the Ria de Vigo. Results showed that the Vigo WWTP is the main driver of microplastics to the Ria de Vigo. Besides, 21% of the released microplastics reach the adjacent ocean, 24% remain anchored around the Cies Islands, and a negligible percentage reaches the upper estuary when the emission occurs under ebb on spring tide conditions. A negligible number of released microplastics is exported to the nearby ocean when the emission occurs under neap tide conditions. This research can provide a useful tool to support the identification of monitoring processes and debris removal.Interreg project | Ref. 0262_MARRISK_1_EFundação para a Ciência e a Tecnologia | Ref. SFRH/BD/114919/2016Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020Xunta de Galicia | Ref. ED431C 2017/6