6 páginas, 3 figuras | Six bimonthly surveys during 2007 were carried out in Magdalena Bay (Mexico) during spring tide conditions. Spatiotemporal variations of temperature, salinity, nitrite, nitrate, ammonium, phosphate and chlorophyll-a were analyzed in the Bay. During spring-early summer (April-June) seawaters were colder and richer in new nutrients and chlorophyll-a than autumn and winter (February and October-December). The coastal upwelling during spring-early summer contributes with new nutrients to the Bay, whereas bottom-recycled nutrients should be the main input during the autumn-winter period. Thus, nutrients availability, dissolved inorganic nitrogen and phosphate, promote a seasonal pattern of phytoplankton biomass in Magdalena Bay. | El presente trabajo se realizó con el apoyo del Instituto Politécnico Nacional a través del proyecto SIP-20070265 | Peer reviewed

La alta estabilidad productiva en ambientes con restricciones hídricas se ha vinculado a la habilidad de conservación del agua por parte de los cultivos. Sin embargo, diferentes especies de malezas, bajo competencia hídrica realizan un uso ineficiente de la misma. Con el objetivo de determinar la estrategia de consumo de agua que poseen <i>Zea mays</i> y <i>Sorghum halepense</i> bajo dos situaciones de disponibilidad hídrica edáfica y trabajando con plantas en contenedores, se estudió la evolución de los potenciales hídricos del suelo (ψs) y de la hoja (ψf), el contenido relativo de agua (CRA) y el intercambio gaseoso foliar durante el período crítico de competencia del cultivo. Además, se calculó la eficiencia en el uso del agua, la complementariedad de recursos por medio de la productividad relativa total (RYT) y la habilidad competitiva a través del índice de agresividad (AGR). Se observó que <i>S.halepense</i> realizó una absorción continua de agua, alcanzando un menor ψf respecto de los híbridos de <i>Z.mays</i>. <i>S.halepense</i> mantuvo el CRA por encima del 90%, alcanzado el 70% sólo en competencia con baja disponibilidad hídrica. En <i>Z.mays</i>, el CRA disminuyó a valores de 70% en ambos niveles hídricos estudiados, manteniendo <i>S.halepense</i> un activo intercambio gaseoso foliar. Los híbridos de <i>Z.mays</i> presentaron una menor habilidad competitiva que <i>S.halepense</i> para ambos niveles de competencia debido a la estrategia conservadora de la humedad que mostró el cultivo. El uso del agua realizado por la maleza podría ser una de las causas de la mayor agresividad de <i>S.halepense</i> bajo las condiciones estudio. | In an environment with water restrictions, the high stability of the production has been linked to the water conservation ability of the crops. However, under water competition, different weed species show inefficient water use. In order to determine the strategy of water consumption of <i>Zea mays</i> and <i>Sorghum halepense</i> under two soil water availability conditions, soil (ψs) and leaf water potential (ψf) trends, relative water content (RWC) and leaf gas exchange were measured during the critical period of crop competition in pot experiments. In addition, efficiency of water use, relative yield total (RYT) and aggressivity index (AGR) of both components were calculated. <i>S.halepense</i> shown a continuous absorption of water, reaching a lower ψf than those observed in <i>Z.mays</i> hybrids. <i>S.halepense</i> maintained the RWC above 90%, reached 70% only in competition with low water availability. In <i>Z.mays</i>, the RWC declined to values of 70% for both water levels studied. <i>S.halepense</i> showed an active leaf gas exchange. <i>Z.mays</i> hybrids have had a less competitive ability that <i>S.halepense</i> for both competition levels due to the conservative water strategy of the crop. Water use by the weed could be a cause of the increased aggressiveness of <i>S.halepense</i> under study conditions. | Facultad de Ciencias Agrarias y Forestales | Instituto de Fisiología Vegetal

O presente trabalho teve como objetivo o desenvolvimento de métodos para determinação simultânea de trialometanos e agrotóxicos organoclorados e piretroides em água. Para proporcionar protocolos experimentais ambientalmente seguros, a cromatografia gasosa com detector por captura de elétrons foi associada a técnicas de preparo de amostra que não emprega solvente orgânico, ou que o volume deste é significativamente reduzido, como é o caso das técnicas de microextração em fase sólida e microextração em gota única, respectivamente. A microextração em fase sólida foi empregada no modo indireto (MEFS-HS), sendo avaliados os fatores adição de sal (Na2HPO4), temperatura e tempo de extração na sua otimização. A microextração em gota única foi empregada por imersão direta (MEGU-ID), sendo as variáveis experimentais solvente extrator, volume da microgota, tempo de contato da microgota com a solução aquosa, velocidade de agitação, adição de sal (NaCl) e volume de amostra avaliados a fim de maximizar o desempenho da técnica. Após a otimização das técnicas, a seletividade, linearidade, precisão intermediária, exatidão e limites de detecção e quantificação dos métodos foram determinados. Os dois métodos permitiram a análise simultânea de agrotóxicos organoclorados e piretroides em água, sendo que a MEFS-HS possibilitou também a análise de trialometanos (THM). Foram obtidos coeficientes de variação (CV) entre 3 e 21% e recuperações relativas entre 70 e 125%. Os protocolos desenvolvidos também apresentaram seletividade e linearidade adequadas, com coeficientes de correlação (r) maiores que 0,95. Os limites de detecção dos analitos de interesse encontram-se entre 0,003 e 3 &#956;g L-1, sendo todos inferiores aos respectivos valores máximos permitidos (VMP) pela legislação nacional (Ministério da Saúde) e internacional (Organização Mundial da Saúde) para água potável. Amostras de água potável foram analisadas empregando os métodos propostos, não sendo detectado nenhum dos agrotóxicos. A partir da MEFS-HS foram detectados nas amostras analisadas os trialometanos clorofórmio, bromodiclorometano e dibromoclorometano em concentrações iguais a 4,4; 3,8 e 0,7 &#956;g L-1, respectivamente. A soma da concentração de trialometanos foi menor do que 9 &#956;g L-1 em todas as amostras analisadas, valor menor do que o VMP estabelecido pela Portaria 518 do Ministério da Saúde, de 25 de março de 2004, que é de 100 g L-1 para a soma dos quatro principais trialometanos. | This study aimed to develop methods for simultaneous determination of organochlorine pesticides, trihalomethanes and pyrethroids in water. In order to provide environmentally friendly experimental protocols, gas chromatography with electron capture detector was associated with sample preparation techniques, that uses no organic solvent, or that this volume is significantly reduced, as in solid phase microextraction and single drop microextraction, respectively. The solid phase microextraction was carried out in the headspace (HS-SPME), and factors such as, addition of salt (Na2HPO4), temperature and extraction time for optimization were evaluated. Single drop microextraction was used in direct immersion mode (MEGU-DI), and experimental variables such as organic solvent, volume of the microdrop, contact time of the microdrop with the aqueous solution, stirring rate, addition of salt (NaCl) and sample volume were evaluated to maximize the performance of the technique. After optimization the methods were validated through the following parameters: linearity, intermediate precision, accuracy and limits of detection and quantification. Both methods allow the simultaneous analysis of organochlorine pesticides and pyrethroids in water, and the HS-SPME also allowed the analysis of trihalomethanes (THM). Coefficients of variation (CV) between 3 and 21% and relative recoveries between 70 and 125% were obtained. The protocols developed also showed selectivity and linearity adequate, with correlation coefficients (r) greater than 0.95. The detection limits of all pesticides under study are between 0.003 &#956;g L-1 and 3 &#956;g L-1, being all below their respective maximum contaminant level (MCL) allowed by national (Ministério da Saúde) and international (World Health Organization) legislation for drinking water. Drinking water samples were analyzed using the proposed methods and any of the pesticides were detected. Using HS-SPME, the trihalomethanes chloroform, bromodichloromethane and dibromochloromethane at concentrations of 4.4, 3.8 and 0.7 &#956;g L-1, respectively, were detected in water samples. The sum of the concentration of trihalomethanes was less than 9 &#956;g L-1 in all samples, a value lower than the MCL established by Brazilian legislation (Portaria 518 of the Ministério da Saúde, March 25, 2004), which is 100 &#956;g L-1 for the sum of the four main trihalomethanes.

Aiming to assess the effects of irrigation amount on vegetative growth, yield and berry composition of the red variety Touriga Nacional (Vitis vinifera L.) a fi eld trial was installed at the “Centro de Estudos Vitivinícolas do Dão”, Nelas, Portugal. The effects of three irrigation treatments (DI30 - 30% of ETc; DI50 - 50% ETc and FI - 100% ETc) were compared to a control non-irrigated (NI) during three growing seasons (2006- 2008). Irrigation affected signifi cantly the fraction of available soil water and the pattern of soil water extraction by the roots either in the row and interrow. Predawn leaf water potential was also infl uenced by irrigation amount being the main differences observed between FI (highest values) and NI (lowest values). Compared to NI, the full irrigation treatment (FI) induced a signifi cantly higher vigour while the defi cit irrigation treatments (DI30 & DI50) returned intermediate values. The FI treatment induced a signifi cantly higher yield as compared to the other treatments which returned similar values. Compared to the control non-irrigated, the defi cit irrigation treatments presented similar berry composition during all the three seasons while the FI treatment showed a signifi cantly higher total acidity, lower total soluble solids and anthocyanins concentration. With the exception of the higher yield observed in FI treatment, in these three seasons irrigation had no other agronomical advantages enabling us to conclude that, in the ecological and viticultural conditions of the experiment, irrigation seems to be not necessary. However, further studies are needed mainly in soils with lower water holding capacity and in dryer years which frequency are expected to increase in the near future as a consequence of the climate change.

A set of human pharmaceuticals enables identification of groundwater that is influenced by sewage and provides information on the time of recharge. As the consumption rates of the investigated pharmaceuticals have changed over time, so too has the composition of the sewage. At the study area, south of Berlin (Germany), irrigation was performed as a method of wastewater clean-up at sewage irrigation farms until the early 1990s. Today, treated wastewater is discharged into the surface-water-stream Nuthegraben. Groundwater and surface-water samples were analyzed for the pharmaceutical substances clofibric acid, bezafibrate, diclofenac, carbamazepine and primidone, the main ions and organic carbon. The pharmaceutical substances were detected at concentrations up to microgram-per-liter level in groundwater and surface-water samples from the Nuthegraben Lowland area and from the former irrigation farms. Concentrations detected in groundwater are generally much lower than in surface water and there is significant variation in the distribution of pharmaceutical concentrations in groundwater. Groundwater influenced by the irrigation of sewage water shows higher primidone and clofibric-acid concentrations. Groundwater influenced by recent discharge of treated sewage water into the surface water shows high carbamazepine concentrations while concentrations of primidone and clofibric acid are low.

The relation between snow water equivalent (SWE) and 28 variables (27 topographically-based topographic variables and canopy density) for the Colorado River Basin, USA was explored through a multi-variate regression. These variables include location, slope and aspect at different scales, derived variables to indicate the distance to sources of moisture and proximity to and characteristics of obstacles between these moisture sources and areas of snow accumulation, and canopy density. A weekly time step of snow telemetry (SNOTEL) SWE data from 1990 through 1999 was used. The most important variables were elevation and regional scale (81 km²) slope. Since the seasonal and inter-annual variability is high, a regression relationship should be formulated for each time step. The inter-annual variation in the relation between SWE and topographic variables partially corresponded with the amount of snow accumulated over the season and the El Niño Southern Oscillation cycle. | Se analiza la relación entre el equivalente de agua en la nieve (SWE) y 28 variables (27 variables topográficas y otra basada en la densidad del dosel) para la Cuenca del Río Colorado, EE.UU. mediante regresión multivariante. Estas variables incluyen la localización, pendiente y orientación a diferentes escalas, además de variables derivadas para indicar la distancia a las fuentes de humedad y la proximidad a las barreras topográficas, además de las características de las barreras topográficas entre las fuentes de humedad, las áreas de acumulación de nieve y la densidad del dosel. Se utilizaron telemetrías semanales de nieve (SNOTEL) desde 1990 hasta 1999. Las variables más importantes fueron la elevación y la pendiente a escala regional (81 km²). Dada la alta variabilidad estacional e interanual, fue necesario establecer regresiones específicas para cada intervalo disponible de datos. La variación interanual en la relación entre variables topográficas y el SWE se corresponde con la cantidad de nieve acumulada a lo largo de la temporada y el ciclo de El Niño-Oscilación del Pacífico Sur.

Hernández-Molina, Francisco J. ... et. al.-- VIII Congreso Geológico de España, 17-19 de julio de 2012, Oviedo | Peer Reviewed

Francisco J. Hernández-Molina ...et al. -- 4 páginas, 3 figuras.-- VIII Congreso Geológico de España, 17-19 de julio de 2012, Oviedo | [EN] An extensive terrace comprising sandy sheeted drifts characterises the proximal sector (close to the Straits of Gibraltar) of the Contourite Depositional System (CDS) of the Gulf of Cadiz and the western continental margin of Portugal. A novel morphosedimentary study over this terrace has been executed based on new multibeam echosounder data, seismic profiles, and surficial sediments samples collected during the CONTOURIBER-1 Cruise (2010). Based on that study, an impressive large channel laterally connected with the central part of the Strait of Gibraltar (Camarinal Sill) has been identified. It is associated southwestward with a huge contourite levee (sand bank), which has been generated by overflow processes related to the Mediterranean Outflow Water (MOW). In the middle to the distal part of the terrace, there are other minor channels, erosional scour alignments and depositional features. The mapping of all these features coupled with CTD data allows to further understand the pathway and deceleration of the MOW, in addition to aid the conceptual identification of contourite terrace. | [ES] El sector proximal del Sistema Deposicional Contornítico (SDC) del Golfo de Cádiz y oeste de Portugal se caracteriza por una extensa terraza contornítica en la que se desarrollan drifts laminares arenosos. Sobre esta terraza se ha realizado un novedoso estudio morfosedimentario en base a datos batimétricos de ecosonda multihaz, registros sísmicos y muestras superficiales, adquiridos en la campaña oceanográfica CONTOURIBER-1 (2010). Se ha identificado un extenso canal sobre dicha terraza conectado lateralmente con la parte central del Estrecho de Gibraltar (Umbral de Camarinal) y bordeado por el SO por un dique (levee) contornítico (banco arenoso). La génesis del canal se relaciona con el desbordamiento sucesivo de la Masa de Agua Mediterránea de Salida (MOW) en el Golfo de Cádiz. En la parte media y distal de la terraza contornítica existen canales menores, surcos erosivos y rasgos deposicionales, cuya cartografía, junto al análisis de datos de CTD, permite entender mejor la circulación y deceleración de la MOW, así como la caracterización conceptual de las terrazas contorníticas. | This research is supported through the project CTM 2008-06399-C04/MAR (CONTOURIBER) and CTM2009-14157- C02. | Peer reviewed

Dissertação de mestrado em Gestão Ambiental e Ordenamento do Território, apresentada à Escola Superior Agrária do Instituto Politécnico de Viana do Castelo | As comunidades dos macroinvertebrados bentónicos são extremamente importantes na estrutura e funcionamento dos ecossistemas aquáticos, constituindo a base de diversas cadeias tróficas. Além disso, são igualmente determinantes no estudo dos ecossistemas em que habitam, pela capacidade de integrar e reflectir as condições do meio. Devido a estas características têm sido amplamente utilizadas em monitorização e avaliação de qualidade ambiental. O presente estudo teve como principais objectivos comparar a composição das comunidades de macroinvertebrados em diferentes locais de amostragem do Rio Estorãos na Área Protegida das Lagoas de Bertiandos e São Pedro de Arcos, assim como o estado físico-químico da água, na perspectiva de avaliar quais os factores que poderão condicionar essas comunidades. Pretendeu-se ainda avaliar a qualidade ecológica desses locais, utilizando diversos índices e inferir sobre o melhor índice (s) a utilizar em avaliações de qualidade ambiental. Realizou-se uma caracterização da área de estudo, através de um enquadramento geográfico, hidrográfico, topográfico e geomorfológico, da caracterização dos seus habitats e da biodiversidade presente e ainda do uso e ocupação do solo, sua evolução e distribuição. Abordou-se a legislação ambiental em vigor e os bioindicadores da qualidade das águas. A definição da localização das estações e frequência das amostragens, recolha e tratamento das amostras, respectiva identificação taxonómica dos macroinvertebrados, tratamento estatístico de todos os dados recolhidos, analise físico-química e biológicas, tiveram como referência, estudos realizados anteriormente, procedimentos claros e expeditos conforme a Directiva Quadro da Água (DQA), indicações metodológicas e respectivos protocolos do Instituto da Água, assim como, diversa bibliografia da especialidade. Os resultados indicaram uma boa qualidade da água, em termos médios, com focos pontuais de degradação, associada à densidade populacional e intensificação agrícola. Contudo, será necessário realizar amostragens noutras épocas do ano, nomeadamente nas estações mais secas, com o objectivo de melhor avaliar a qualidade da água e os efeitos da pressão antropogénica neste curso de água. As conclusões e as consequentes acções e recomendações para trabalhos futuros sobre gestão de sistemas fluviais, conduzem à implementação de medidas mitigadoras, quer em termos de ordenamento e planeamento dos recursos e gestão integrada das actividades, quer em termos de promoção dos habitats e condições naturais associadas. | The benthonic macro-invertebrate communities are extremely important in the structure and functioning of the aquatic ecosystems, setting up the basic to several trophic chains. Besides, they are also decisive in the study of ecosystems they live in, because of their ability to integrate and reflect the conditions of the environment. Due to these characteristics they have been used in monitoring and evaluation of the environment quality. The main objective of this study was to compare the composition of the benthonic macro-invertebrate communities from different sample-collection locations of the river Estorãos in the Protected Area of Lagoas de Bertiandos e São Pedro de Arcos, as well as the physic-chemical water properties, in an attempt to evaluate the conditions that affect those communities. It was also intended to evaluate the ecologic quality of those locations using several biological and physic-chemical indicators, in order to assess those that may be better used in environmental quality evaluation. The characterization of the site was done using a geographic, hydrographic, topographic and geomorphologic setting. It was characterized its habitats, and the biodiversity present and finally the evolution and distribution of soil use and occupation. It was studied the present environmental legislation as well as the indicators used for water quality evaluation. The definition of the locations and frequency of sample-collection, gathering and management of the samples, taxonomical identification of the macro-invertebrates, statistic analysis, physic-chemical and biological analysis, were done using previous studies methodologies, clear and expeditious procedures in accordance to “Directiva Quadro da Água” (DQA), methodological indications and the respective protocols from the “Instituto da Água”, as well as several other scientific references. The results indicated that, in general, the water quality was good, with specific focus of water degradation associated to the population density and agricultural intensification. However, it is necessary to conduct sampling in other seasons, especially in drier seasons, in order to better assess water quality and the effects of anthropogenic pressure in the river Estorãos. The conclusions and consequent actions and recommendations to future studies about the management of fluvial systems, lead to the implementation of mitigating measures, either in terms of resources distribution and planning and activities integration, or in terms of promotion of the habitats and natural conditions associated.