Caracterización de la calidad de sedimentos afectados por vertidos de petróleo: comparación entre casos de vertidos accidentales (impacto agudo) frente a derrames continuos (impacto crónico)

La tesis presenta un estudio integral para carácterizar la calidad de sedimentos de dos áreas dél litoral españól afectadas por vertidos¿ de hidrocarburos. A finales del 2002 el accidente del petrolero monocasco Prestige provocó un vertido de 63000 toneladas de fuel oil pesado que se esparció en manchas, más o menos compactas y que supuso un impacto agudo de contaminación provocando una de las "mareas negras' más dañinas de las ocurridas en Galicia en los, últimos años Por-otra parte, la Babia de Algeciras se ve afectada de manera continua por vertidos- de distinta naturaleza procedentes de la intensa actividad urbana e industrial que se desarrolla en el área, así como una intensa actividad portuaria y tráfico marítimo. Todo ello hace que la Babia de Algeciras sufra de forma rutinaria vertidos de petróleo. En una primera fase de aplicación del modelo integrado se désarrolló la fase inicial de "screening' con la aplicación de sólo dos lineas de evidencia sobre un número extenso de estaciones. El resultado de la aplicación de esta primerá fase permitió la selección de un número menor de estaciones sobre las que se va a desarrollar el modelo integrado de forma completa. Esta incluye cuatro líneas de evidencia: contaminación, toxicidad, alteración "in situ' y bioacumulación y biomagnificación. Se ha llevado a cabo una nueva mejora en la metodología integrada de evaluación de la calidad de los sedimentos dentro del marco del "Weight of Evidence approach" que ha permitido obtener resultados más objetivos. Se ha demostrado como tras el vertido los PAHs ifieron el principal contaminante de la costa gallega. Se ha identificado la existencia de fuentes de metales en el Parque Nacional de las Islas Atlánticas y de la bahía de Corme-Laxe que aparentemente no están produciendo efectos biológicos de tipo agudo. La polución ha disminuido en los últimos afios en ambas zonas de Galicia, aunque aún existe cierto estrás ambiental principalmente en las zonas estudiadas de la bahía de Cocine-Laxe. Se han demostrado las ventajas de incorporar los biomarcadores como línea de evidencia dentro de un estudio integrado, éstos han mostrado una mayor sensibilidad en los resultados a la hora de cuantificar la polución e identificar la misma; el uso de los biomarcadores obtenidos en exposiciones de campo y laboratorio dentro del eight of Evidence approach" ha ayudado a relacionar las fuentes de contaminación y los efectos incluso cuando el contaminante no ha sido analizado. A pesar que varios años después del vertido no se han detectado efectos agudos significativos en el área de Conne-Laxe, se han observado respuestas subletales relacionadas con las concentraciones de contaminantes como los Palis, y los metales Ph y Hg. La presencia de ciertos metales como Zn, Cu y Ni en las islas Cíes podrían suponer un riesgo aunque por el momento no se han detectado efectos biológicos en la zona asociados con estos contaminantes. Tras los resultados obtenidos en la Bahía de Corme-Laxe, se sospecha que la presencia de las bateas de cultivo de mariscos pueda suponer una fuente de estrés importante en la zona. La existencia de distintas fuentes de contaminación da lugar a la presencia de una mezcla compleja de contaminantes en la Bahía de Algeciras, incluyendo vertidos industriales, urbanos y derivados del tráfico marítimo y de las actividades de bunkering: Todo elio se refleja en una alta degradación ambiental debida a la entrada continuada de estos vertidos. Por otro lado, cuatro años después del vertido del petrolero Prestige se observa una recuperación generalizada de los sedimentos del Parque Nacional de las islas Atlánticas y una mejora én la calidad de la Bahía de Corme-Laxe. El método integrado ha de la recuperación del sistema afectado en la costa de Galicia, la polución en la zona de la Bahía de Algeciras y la condición de zona de referencia en la estación elegida en la Bahía de Cádiz. Se ha demostrado la capacidad ambiental de recuperación tras un gran vertido de petróleo como el ocurrido en Galicia en 2002 mientras que sedimentos litorales que se ven afectados por moderadas dosis de vertidos durante un largo periodo de tiempo y que en un principio no desatan tanta alarma social pueden resultar notablemente más degradados como es el caso de la Bahía de Algeciras

Strategic environmental sensitivity mapping for oil spill contingency planning in the Peruvian marine-coastal zone

Major oil spills can cause significant impacts on marine-coastal zones, particularly on areas with a high oil spill risk, which combine a high oil spill hazard-high likelihood of oil stranding at high concentrations, and a high environmental sensitivity-high concentration of highly sensitive ecological and socioeconomic resources. In this context, a straightforward multicriteria methodology is proposed to determine the second factor of the oil spill risk, namely the strategic environmental sensitivity (SES), in 68 sectors covering the entire Peruvian marine-coastal zone. The methodology comprised the weighted integration of physical, biological, and socioeconomic sensitivity indicators based on their relevance in surface marine oil spills and the Peruvian ecological and socioeconomic context. As a result, relative SES levels from very low to very high were assigned to the sectors. To demonstrate the SES applicability, an oil spill risk assessment at a screening level was performed in a selected sector with current oil production activities. The oil beaching likelihood of worst-case discharge scenarios modelled for January 2021 was used to determine an overall screening oil spill hazard level in the selected sector, while a matrix relating the SES and hazard determined the screening oil spill risk. The results can be used as a decision-support tool to enhance the oil spill contingency planning in Peru or be used in other relevant processes such as the integrated coastal zone management, the marine spatial planning, or the contingency planning of other liquid contaminants. In addition, the proposed methodologies can be adapted to different local and international contexts and scales

Marine Litter Windrows: A Strategic Target to Understand and Manage the Ocean Plastic Pollution

Windrow is a long-established term for the aggregations of seafoam, seaweeds, plankton and natural debris that appear on the ocean surface. Here, we define a "litter windrow" as any aggregation of floating litter at the submesoscale domain (<10 km horizontally), regardless of the force inducing the surface convergence, be it wind or other forces such as tides or density-driven currents. The marine litter windrows observed to date usually form stripes from tens up to thousands of meters long, with litter densities often exceeding 10 small items ( 2 cm) per m2 or 1 large item ( 2 cm) per 10 m2. Litter windrows are generally overlooked in research due to their dispersion, small size and ephemeral nature. However, applied research on windrows offers unique possibilities to advance on the knowledge and management of marine litter pollution. Litter windrows are hot spots of interaction with marine life. In addition, since the formation of dense litter windrows requires especially high loads of floating litter in the environment, their detection from space-borne sensors, aerial surveys or other platforms might be used to flag areas and periods of severe pollution. Monitoring and assessing of management plans, identification of pollution sources, or impact prevention are identified as some of the most promising fields of application for the marine litter windrows. In the present Perspective, we develop a conceptual framework and point out the main obstacles, opportunities and methodological approaches to address the study of litter windrows.This study is an outcome of the research project entitled "MappingWindrows as Proxy for Marine Litter Monitoring from Space" (WASP), funded by the European Space Agency (ESA) Contract No. 4000130627/20/NL/GLC, within the Discovery Campaign in Marine Litter. AC had additional support from MIDaS (CTM2016-77106-R, AEI/FEDER/UE), and SA from PRIN 2017-2017WERYZP-EMME project. AI was supported by the Environmental Research and Technology Development Fund (JPMEERF18S20201) of the Ministry of the Environment, Japan, and by SATREPS of Japan International Cooperation Agency and Japan Science and Technology Agency. OB and AR contribution was funded through the EU's LIFE Program (LIFE LEMA project, grant agreement no. LIFE15 ENV/ES/000252). This is contribution number 1016 of AZTI, Marine Research, Basque Research and Technology Alliance (BRTA)

Artisanal trawl fisheries as a sentinel of marine litter pollution

Systematic seafloor surveys are a highly desirable method of marine litter monitoring, but the high costs involved in seafloor sampling are not a trivial handicap. In the present work, we explore the opportunity provided by the artisanal trawling fisheries to obtain systematic data on marine litter in the Gulf of Cadiz between 2019 and 2021. We find that plastic was the most frequent material, with a prevalence of single-use and fishing-related items. Litter densities decreased with increasing distance to shore with a seasonal migration of the main litter hotspots. During pre-lockdown and post-lockdown stages derived from COVID-19, marine litter density decreased by 65 %, likely related to the decline in tourism and outdoor recreational activities. A continuous collaboration of 33 % of the local fleet would imply a removal of hundreds of thousands of items each year. The artisanal trawl fishing sector can play a unique role of monitoring marine litter on the seabe

The Zoning of Semi-Enclosed Bodies of Water According to the Sediment Pollution: The Bay of Algeciras as a Case Example

This paper reports a study of the occurrence and levels of polycyclic aromatic hydrocarbons (PAHs) in a bay characterised by a chronic persistent impact. A total of 55 sediment samples were taken at different depths up to 111 m in two sampling campaigns. Chemical analyses were carried out by gas chromatography-mass spectroscopy. The results indicate that: (1) significant spatial variations exist, (2) levels of PAHs are related more strongly to the spatial distribution of sediments than to mineralogy/granulometry, (3) the sediments are slightly-to-moderately contaminated by PAHs, and (4) these PAHs derive from pyrolytic and petrogenic sources. Through use of an innovative data classification system (proposed according to depth and spatial location of sampling points), and using factorial and cluster techniques, five zones have been differentiated depending on the contamination level and source

Author Correction: Floating macrolitter leaked from Europe into the ocean (Nature Sustainability, (2021), 4, 6, (474-483), 10.1038/s41893-021-00722-6)

During the preparation of the Supplementary Data spreadsheet “S. Data 3_Regression data,” the mean and median confidence intervals (CI) of FML (items yr−1) were misplaced in relation to their corresponding river names. The Supplementary Data file has now been updated in the HTML version of the article. This update does not alter the results or conclusions of this article.Correction to: Nature Sustainability https://doi.org/10.1038/s41893-021-00722-6, published online 10 June 2021. During the preparation of the Supplementary Data spreadsheet “S. Data 3_Regression data,” the mean and median confidence intervals (CI) of FML (items yr−1) were misplaced in relation to their corresponding river names. The Supplementary Data file has now been updated in the HTML version of the article. This update does not alter the results or conclusions of this article.Peer reviewe

Predictive Power of the "Trigger Tool" for the detection of adverse events in general surgery: a multicenter observational validation study

Background In spite of the global implementation of standardized surgical safety checklists and evidence-based practices, general surgery remains associated with a high residual risk of preventable perioperative complications and adverse events. This study was designed to validate the hypothesis that a new “Trigger Tool” represents a sensitive predictor of adverse events in general surgery. Methods An observational multicenter validation study was performed among 31 hospitals in Spain. The previously described “Trigger Tool” based on 40 specific triggers was applied to validate the predictive power of predicting adverse events in the perioperative care of surgical patients. A prediction model was used by means of a binary logistic regression analysis. Results The prevalence of adverse events among a total of 1,132 surgical cases included in this study was 31.53%. The “Trigger Tool” had a sensitivity and specificity of 86.27% and 79.55% respectively for predicting these adverse events. A total of 12 selected triggers of overall 40 triggers were identified for optimizing the predictive power of the “Trigger Tool”. Conclusions The “Trigger Tool” has a high predictive capacity for predicting adverse events in surgical procedures. We recommend a revision of the original 40 triggers to 12 selected triggers to optimize the predictive power of this tool, which will have to be validated in future studies

PollutionTracker: A new partner-based initiative to monitoring coastal contamination

Research and monitoring of contaminants in the marine environment have been important in prioritizing pollutants of concern, devising mitigation strategies and documenting environmental responses to regulations and source control. Despite site-specific monitoring efforts for some contaminants in some areas, there exists today a distinct lack of information on contaminant trends or concerns across coastal British Columbia. The PollutionTracker is a novel Vancouver Aquarium-led initiative that is bringing multiple partners together to create an open and harmonized environmental monitoring framework. PollutionTracker is implementing stringent site selection, sample collection, analytical and interpretative protocols in support of a coast-wide contaminant assessment in nearshore British Columbia. High resolution contaminant analyses performed every two years on samples of sediments and mussels will provide insight into the state of the coastal environment. These two matrices have been routinely used by managers and stakeholders in the US, Europe and Asia to, but has never been carried out in Canada. PollutionTracker plans to link with ongoing initiatives across the border while it aims to provide information on status and trends on a variety of priority pollutants that will in turn improve our understanding of source, transport, fate and effects of these substances, risks to biota, and the safety of traditional seafoods for coastal First Nations

Multi-agency environmental monitoring following the MV Marathassa oil spill in Vancouver in April 2015: are we ready for a big one?

On the morning of April 9th 2015, citizens of Vancouver (British Columbia) awoke to the sights and smells of oil on the waters and beaches of popular English Bay. At the time of the incident, considerable confusion existed about the source of the oil, the type of oil involved, and the amount spilled. Loss of federal capacity in recent years added to the confusion, with no coherent environmental monitoring plan implemented, and several concerned agencies leading their own sampling as a result. Early reports ascertained that a leak beginning around 5 pm on April 8 from the grain carrier MV Marathassa released an estimated 2,700 L of bunker C fuel overnight. This spill presented a direct threat to the local environment, as well as to the Vancouver Aquarium, which draws seawater for its collections from local waters off Stanley Park. Immediately upon learning of the incident from the news, the Vancouver Aquarium deployed five teams to respond or prepare as required. These included Ocean Pollution scientists, Marine Mammal scientists, marine mammal rescue, a dive team, and facility water managers. Emergency measures were implemented for water operations at the Aquarium, and seawater intakes were closed for an unprecedented four days. The Vancouver Aquarium conducted a forensic fingerprinting analysis of oil from the ship, oil from several shoreline locations, water samples at and around the seawater intakes, and other environmental samples. Staff scientists were able to use these hydrocarbon signatures to confirm the spread of Bunker C fuel as far as 13 km from the vessel, and well into Burrard Inlet. The modest MV Marathassa spill underscored the distinct need for baseline hydrocarbon levels and profiles for coastal British Columbia in support of improved understanding of the source, transport fate and effects of hydrocarbons from a multitude of natural and anthropogenic sources