Eutrophication and enteropathogens as risk factors for avian botulism outbreaks in wetlands receiving effluents from urban wastewater treatment plants

Due to the scarcity of water resources in the “Mancha Húmeda” Biosphere Reserve, the use of treated wastewater has been proposed as a solution for the conservation of natural threatened floodplain wetlands. In addition, wastewater treatment plants of many villages pour their effluent into nearby natural lakes. We hypothesized that certain avian pathogens present in wastewater may cause avian mortalities which would trigger avian botulism outbreaks. With the aim of testing our hypothesis, 24 locations distributed in three wetlands, two that receive wastewater effluents and one serving as a control, were monitored during a year. Sediment, water, water bird feces, and invertebrates were collected for the detection of putative avian pathogenic Escherichia coli (APEC), Salmonella spp., Clostridium perfringens type A, and Clostridium botulinum type C/D. Also, water and sediment physicochemical properties were determined. Overall, APEC, C. perfringens, and C. botulinum were significantly more prevalent in samples belonging to the wetlands which receive wastewater. The occurrence of a botulism outbreak in one of the studied wetlands coincided with high water temperatures and sediment 5-day biochemical oxygen demand (BOD5), a decrease in water redox potential, chlorophyll a, and sulfate levels, and an increase in water inorganic carbon levels. The presence of C. botulinum in bird feces before the onset of the outbreak indicates that carrier birds exist and highlights the risk of botulinum toxin production in their carcasses if they die by other causes such as bacterial diseases, which are more probable in wastewater wetlands

Sostenibilidad en la Ingeniería Civil. Una experiencia piloto de formación profesional y aprendizaje cooperativo

A Pilot Experience on Cooperative Learning was developed with vocational training students of Advanced Level in Building Construction and Civil Engineering of the Atenea Secondary School (Ciudad Real). The aim was to improve their professional skills in the field of sustainability and, in particular, wastewater treatment by planning, designing, projecting and building artificial wetlands; this a innovative and distinctive competence that will facilitate their employment in an environment with demand for skilled technicians in water purification systems that are more sustainable in both environmental, energy and economical terms. For this purpose, a transdisciplinary team of university professors was formed, who are specialized on building and civil engineering, environmental technology, ecology, ecological engineering, hydraulics, hydrology, geotechnics, geology, geomorphology, geography, territorial planning, teaching and pedagogy. The methodology used was Project Based Learning (PBL), that has been used for some of the team members since 1999 in the Faculty of Civil Engineering of the Universidad de Castilla-La Mancha (UCLM). Students were asked to propose, design and project an artificial wetland to treat wastewater from a rural home, museum or restaurant that they had projected earlier to rehabilitate the ruins of a 19th century water-energy-industrial foundry known as Martinete de Los Pozuelos de Calatrava (Ciudad Real). The major milestones of the pilot experience were: i) Pre-assessment of students knowledge, ii) Lectures to provide new theoretical concepts essential to develop foreseen specific, iii) Independent student work supervised by teachers from closed scripts and supply of teaching materials and literature, iv) Classroom and field workshops, v) Continuous assessment of individual work in class (interest, participation, success in the resolution of the issues raised by the teacher), final evaluation in group through oral presentation and written report, and issuing diplomas for further recognition of free credits, vi) Evaluation of the pilot experience was done by surveying students about methodology, content and development of classes, results obtained and other comments that they wished to include, vii) Dissemination by opening an account in the facebook social network, writing a press release for publication in local media, and professional editing a CD with graphic and teaching materials. The most remarkable result of the pilot is that PBL methodology is a revolution for vocational training students, used to deal with tools and practicalities commonly based on closed standards and protocols; instead, cooperative learning requires facing real limitations, such as a relative lack of information, developing the project with this uncertainty, and making decisions on the level of complexity of the solutions to adopt. This has resulted in an overall very positive experience for the students (over 95%), who were especially pleased with the results (100%) and the content and development of educational activities (more than 95%)

Advances in high water modelling to improve climate change adaptation, flood risk reduction and stormwater management

Probabilistic modelling of extreme events has a crucial role in both reducing flood risks, improving our adaptation to climate change, and managing local stormwater. Empirical flow records are suitable for it just since recently. The alternative hydrological modelling with rainfall input data has been the Gumbel distribution. This prevails since 1941, despite Gumbel?s obvious warn about that no changes in both climate and the basin should occur within the observation nor forecasting periods. Thus, advances in flood modelling are today needed because: i) criticism against Gumbel distribution on both theoretical, empirical and even ethical grounds, ii) gauge data are increasingly available at even 15? interval, iii) the dynamics of great weather types and large atmospheric circulation systems are better know, allowing downscaling to hydrological processes, and iv) forecasting has to take into account climate change and anthopogenic impact on river systems. We validate here a new approach to analyse time series of river flow and reveal flood recurrence and magnitude. Classical autocorrelation analysis (AA) is used, but considering a wider range of return periods than usual; thus, results are applicable to more time scales, including climate change adaptation, flood risk reduction and stormwater management. Further, so calculated return periods are validated against the occurrence of objective great weather events (GWL)

Networking biosphere reserves through corridors on the basis of the millenium ecosystem assessment

The present work roots on the Madrid Action Plan (MAP) 2008-2013 for the UNESCO World Network of Biosphere Reserves (WNBR), which faces emerging challenges related to the provision of ecosystem services. These are recognized by the MAP as a useful framework to superimpose on the multiple functions of Biosphere Reserves, ranging from protection to production in landscapes. The essence of Biosphere Reserves as sustainable development sites is accordingly seen as an effort to preserve and promote place-specific mixes of supporting, provisioning, regulating, and cultural ecosystem services that enable the environmental, economic, and social well-being of resident and stakeholder communities. We report here research, management and socio-economic achievements after 30 years of active and continuing consultations between the scientific and research communities, policy and decision makers, resource managers and resident populations in the Mancha Húmeda Biosphere Reserve (MHBR), paying attention to their critical role in finding the optimal mix of ecosystem services that reveal MHBR as a model for land level sustainable development at the national and global levels. Besides, regional and national networks of Biosphere Reserves play an essential role within the broader WNBR. Accordingly, it is also presented how the practical knowledge, experience and infrastructure available at the MHBR since its designation in 1980 may be applied within a network of Biosphere Reserves at the scale of the Upper Guadiana Catchment, increasing its scope and regional influence. For that purpose, river and cattle trail corridors are considered, together with stepping-stones connectivity between wetlands and eventual extension to two new Biosphere Reserves, i.e. Campo de Calatrava and Montes de Toledo; such an integrated network would result in mutual reinforcement, increased visibility and greater dynamism among the three resulting Biosphere Reserves within the network. Finally, assessment of MHBR ecosystem services is used to discuss the demand of conservationists in 2008 to retire it the condition of Biosphere Reserve on the basis of the environmental problems suffered by one among its numerous natural reserves, dismissing efforts throughout years

Analysis of microbial mats metabolism with microsensors after incubation under different light sources

Since electrochemical microsensors became commercially available, experimental applications of this advanced technique attracts increasing attention from average limnologists. This work aims at sharing results of analysing metabolism in stratified communities from the Chiprana salt-lake (SE Spain) for three metabolism attributes, which are representative of photosynthesis and respiration. Microbial mats from this lake, the only permanent hypersaline one in Spain, were incubated until stabilization in aquariums under four light sources, i.e. indoor sunlight, a Carrefour 12 W fluorescent tube, and shadowed and unshadowed Osram Decostar 50 W halogen lamps. Photosynthetic active radiation (PAR) was measured with a Li-Cor LI-1000 datalogger and flat quantum sensor. Unisense MiniProfiler MP4 microsensors for dissolved oxygen (Clark), pH and redox potential were used to compare the adequacy of light sources for mat growth and development. Three vertical microprofiles per attribute and light treatment were performed (total height about 1 cm, measurement interval 50 µ), in randomly-selected locations throughout microenvironment surface. PAR values (µmol s-1 m-2) were lower under halogen than under fluorescent light (8,33 in shadowed and 15,59 in unshadowed, vs. 17,40 in fluorescent treatment). The highest PAR values were recorded under sunlight (478 µmol s-1 m-2). Absolute maximum mat metabolism was higher under shadowed halogen light (27,24 mg O2 L-1), but average maximum value for the three unshadowed locations was higher. However, dissolved oxygen in the later was most variable across depth among all treatments (coefficient of variation 211-246 %). These results show that light source attributes (intensity and PAR) do not show simple correspondence with metabolism attributes. The highest values of dissolved oxygen were recorded under light sources with the lowest PAR values, but not necessarily with the lowest light intensities. Despite this apparent prevalence of light quality, excessive intensity might explain differences between shadowed and unshadowed halogen treatments

Tendiendo puentes entre educación secundaria y superior, aprendizaje cooperativo aplicado a sostenibilidad en ingeniería civil

A Pilot Experience on Cooperative Learning was developed with vocational training students of Advanced Level in Building Construction and Civil Engineering of the Atenea Secondary School (Ciudad Real). The aim was to improve their professional skills in the field of sustainability and, in particular, wastewater treatment by planning, designing, projecting and building artificial wetlands; this a innovative and distinctive competence that will facilitate their employment in an environment with demand for skilled technicians in water purification systems that are more sustainable in both environmental, energy and economical terms. For this purpose, a transdisciplinary team of university professors was formed, who are specialized on building and civil engineering, environmental technology, ecology, ecological engineering, hydraulics, hydrology, geotechnics, geology, geomorphology, geography, territorial planning, teaching and pedagogy. The methodology used was Project Based Learning (PBL), that has been used for some of the team members since 1999 in the Faculty of Civil Engineering of the Universidad de Castilla-La Mancha (UCLM). Students were asked to propose, design and project an artificial wetland to treat wastewater from a rural home, museum or restaurant that they had projected earlier to rehabilitate the ruins of a 19th century water-energy-industrial foundry known as Martinete de Los Pozuelos de Calatrava (Ciudad Real). The major milestones of the pilot experience were: i) Pre-assessment of students knowledge, ii) Lectures to provide new theoretical concepts essential to develop foreseen specific, iii) Independent student work supervised by teachers from closed scripts and supply of teaching materials and literature, iv) Classroom and field workshops, v) Continuous assessment of individual work in class (interest, participation, success in the resolution of the issues raised by the teacher), final evaluation in group through oral presentation and written report, and issuing diplomas for further recognition of free credits, vi) Evaluation of the pilot experience was done by surveying students about methodology, content and development of classes, results obtained and other comments that they wished to include, vii) Dissemination by opening an account in the facebook social network, writing a press release for publication in local media, and professional editing a CD with graphic and teaching materials. The most remarkable result of the pilot is that PBL methodology is a revolution for vocational training students, used to deal with tools and practicalities commonly based on closed standards and protocols; instead, cooperative learning requires facing real limitations, such as a relative lack of information, developing the project with this uncertainty, and making decisions on the level of complexity of the solutions to adopt. This has resulted in an overall very positive experience for the students (over 95%), who were especially pleased with the results (100%) and the content and development of educational activities (more than 95%)

Climate change footprint in the Mancha húmeda biosphere reserve

The Mancha Húmeda Biosphere Reserve (MHBR) is the widest inland steppe wetlands area of the Iberian Peninsula; this wetland district sums up to 30.000 ha of aquatic ecosystems, with a high surface density and physiographic and ecological diversity. The MHBR is a hot spot for biological conservation, resulting in a variety of natural reserves, from international scope, i.e. Ramsar Sites of Internatonal Importance, and Sites of Nature Conservation Interest (SNCI) and Special Protection Areas for Wild Birds (SPA) of the Natura 2000 Network of the EU, to national scope, i.e. the National Park of Tablas de Daimiel, and even regional scope, i.e. a number of Natural Reserves, Microrreserves, and Geological Monuments. At the scale of species and communities, the MHBR hosts also many endemisms and other species with limited geographic distribution, rare species and many habitats included in the Habitats Directive of the EU. Aquatic ecosystems are distinctive elements of the MHBR. Most of them are temporary and its hydroperiod is very variable as a result of its Mediterranean, continental, semiarid climate. Consequently, we hypothesize that the MHBR is very sensitive to global change. Regarding aquatic ecosystems, rainfall variation, temperature rise and climate instability would be already causing disturbances in their natural dynamics, e.g. modifications of hydrogeochemical processes, food webs, and populations). On the basis of results of limnological monitoring in the later 30 years in wetlands, floodplains and reservoirs of the MHBR, this work intends to reveal whether climate change is significantly affecting the natural dynamics of these aquatic ecosystems, rather than other local and regional impacts, such as variations in water quality and quantity because of wastewater inputs

Estudio de los riesgos sanitarios para las aves acuáticas asociados con el abastecimiento de las Tablas de Daimiel y otros humedales manchegos con aguas residuales urbanas tratadas

La escasez de agua en la cuenca alta del río Guadiana ha hecho que se valore el uso de de las aguas residuales depuradas para la conservación de la biodiversidad de humedales como Las Tablas de Daimiel. En este trabajo hemos abordado el estudio de: (1) el riesgo que suponen las aguas residuales para aumentar la presencia de enteropatógenos en el medio y en las aves; (2) las condiciones ambientales que favorecen la presencia de Clostridium botulinum en el medio y la aparición de brotes de botulismo, incluyendo estudios experimentales y de campo; y (3) el papel de los invertebrados acuáticos, los dípteros necrófagos y las propias aves en la expansión los brotes de botulismo. La presencia de Escherichia coli patogénica aviar (APEC), Clostridium perfringens tipo A y C. botulinum tipo C/D ha sido generalmente mayor en muestras de agua, sedimento y heces de aves de las lagunas que reciben directamente aguas residuales (Navaseca y Veguilla) respecto a las Tablas de Daimiel. La aparición de un brote de botulismo en Navaseca en verano de 2010 estuvo asociado con una bajada del potencial redox, clorofila y sulfatos en el agua, de la DBO5 en sedimento y con un aumento del carbono inorgánico en el medio. Las condiciones de anoxia generadas, posiblemente asociadas con una proliferación de Lemna en la laguna, favorecieron la proliferación de C. botulinum. En muestreos previos a brotes de botulismo la mayor presencia de C. botulinum fue detectada en heces de aves, para después ser detectada en muestras de sedimento, agua, gasterópodos acuáticos, invertebrados acuáticos, moscas necrófagas y sus larvas. La muerte por cualquier motivo (p.e. infecciones por enterobacterias) de aves acuáticas con C. botulinum en su tracto digestivo actuaría como detonante de los brotes al servir el cadáver como medio de crecimiento de la bacteria y proliferación de larvas de mosca acumuladoras de toxina que pueden ser ingeridas por otras aves. Además se ha comprobado experimentalmente que las moscas son capaces de transportar C. botulinum a cadáveres exentos previamente de la bacteria, dando lugar así a larvas tóxicas que pueden iniciar el ciclo cadáver-larva-ave que magnifica los brotes de botulismo. Las aves afectadas por botulismo pueden excretar C. botulinum más de 2 semanas después del ingreso en los centros de recuperación para su tratamiento, por lo que el papel de las aves en la dispersión de la bacteria durante los brotes puede ser importante. En conclusión, los humedales abastecidos con aguas residuales podrían actuar como trampas ecológicas para las aves acuáticas por el riesgo de exposición a enteropatógenos y brotes de botulismo