Environmental indicators of ecological integrity and their development for running waters in northern Portugal

The recognition of deleterious effects of the destruction and loss of habitats (e.g. regularization of rivers, dredging, water diversion), chemical pollution, eutrophication, and climatic alterations on the aquatic organisms, as a result of human activities, combined with an urgent need of a more environmentally sensitive and ecologically sustainable management of Portuguese river systems , made us seek methods that assess the ecological condition of these systems. This article tries to make a revision of the concept of ecological integrity and the methods commonly used to assess it. Different approaches to establish the reference condition for bio-assessment are also indicated. Finally it shows the new methodologies that have been developed in Portugal for assessing the ecological condition of streams and new directions in the evaluation processes based on a better understanding of the entire aquatic ecosystem are also pointed out. An enormous challenge consists in the integration of various measurements of riverine attributes founded on key ecological processes, and in the development of more dynamic approaches that might together establish river condition and their dependence along multiple temporal and spatial scales.El reconocimiento de los efectos deletéreos de la destrucción y pérdida de hábitat (por ejemplo la regularización de ríos, el dragado o la extracción de agua), la polución química, eutrofización y alteraciones climáticas en los organismos acuáticos, como resultado de las actividades humanas, combinados con una necesidad urgente de una gestión ambientalmente más sensible y ecológicamente sustentable de los sistemas lóticos portugueses, nos incito a buscar métodos que evalúen la condición ecológica de estos sistemas. Este artículo intenta hacer una revisión del concepto de integridad ecológica y los métodos usados para evaluarlo. También son abordadas maneras diferentes de establecer la condición de referencia para la evaluación biológica. Finalmente muestra las nuevas metodologías que se han desarrollado en Portugal para evaluar la condición ecológica de los ríos y también son indicadas las nuevas direcciones en los procesos de evaluación basados en un mejor entendimiento de todo el ecosistema acuático. Un desafío enorme consiste en la integración de varias dimensiones de atributos fluviales fundamentada en los procesos ecológicos importantes y en el desarrollo de métodos más dinámicos que juntos podrán establecer la condición de los ríos y su dependencia a lo largo de múltiplas escalas temporales y espaciales

Combining Radio and PIT-Telemetry to Study the Large and Fine-Scale Movements of Stocked and Wild Brown Trout (Salmo trutta L.) in a Northeastern Stream, Portugal

Stream-resident salmonid movements have been the subject of numerous studies and their behaviour is relatively well-known (Harcup et al., 1984; Heggenes, 1988). For example, brown trout (Salmo trutta) is described as a sedentary species based on the behaviour displayed, often associated to the strong site attachment to a territory or home range (Bridcut & Giller, 1993; Armstrong & Herbert, 1997). Other salmonids like brook (Salvelinus fontinalis) (Roghair & Dolloff, 2005) and cutthroat trout (Oncorhynchus clarki) (Hegennes et al., 1991) showed similar behaviour. However, there are studies reporting a wide range of movements for brown (Meyers et al., 1992; Young, 1994), cutthroat (Hilderbrand & Kershner, 2000) and brook (Gowan & Fausch, 1996) trout populations. Trout behaviour can be modified by natural (e.g. fish density, food availability) and especially by man induced factors (e.g. environmental degradation, harvest and stocking) responsible for major threats of wild populations (Laikre et al., 2000). Indeed, stocking of hatchery-reared brown trout is a management tool commonly used to improve the recreational fishing (Cowx, 1999). This activity is responsible for a sudden artificial increase of fish density in a particular area. Negative impacts on wild populations, such as genetic contamination, competition, predator attraction and disease transmission were often referred (White et al., 1995; Einum & Fleming, 2001; Weber & Fausch, 2003) and are potentially amplified with the dispersal failure, since many hatchery-reared trout tend to remain near of the stocking site (Cresswell, 1981; Aarestrup et al., 2005). There are also contradictory results, as reported by Bettinger & Bettoli (2002) where stocked trout dispersal reached over 12 km in the downstream direction, just 24 hours after their release. Cortes et al. (1996) found for Portuguese salmonid streams that, during three successive years (2000 to 2003), less than 20% of stocked brown trout remained in the stream segment, one month after the release. However, in this study a mark-recapture method was used that did not allow to assess the main causes of the fish depletion and was not appropriate for the observation of fish behaviour

Natural and anthropogenic variations in a channelized water course in Centre of Portugal

The present study took place in the Mondego River, located in the Centre of Portugal. The lower sector of the river (Lower Mondego) is largely man-made due to regularization and rectification of the channel. The objective was to assess the impacts on the aquatic communities (fishes and benthic invertebrates). Fauna inventories were performed in June and September of 2000 and 2001, together with habitat characterization. Three sampling sites were selected in this segment and compared to a reference site located upstream. It is concluded that the presence of structures such as submerged weirs and riprap, promoted the diversity, due to the physical complexity, which they introduced into the system. The dramatic flood peaks that occurred in the winter of 2000/01 also caused substantial changes in the fluvial dynamics and in the habitats: the large amount of suspended solids transported resulted in a riverbed of unstable fine materials, and in a subsequent biological impoverishment. However, both communities displayed a high resilience to these changes; the inter-annual differences being obscured by the seasonal ones on macroinvertebrate communities.El presente trabajo tuvo lugar en el río Mondego, localizado en el Centro de Portugal. El tramo bajo del río (Bajo Mondego) se encuentra intensamente transformado debido al regularización y rectificación del cauce. El objetivo fue evaluar los impactos en las comunidades acuáticas (peces e invertebrados bentónicos). Se realizaron inventarios de fauna en Junio y Septiembre de 2000 y 2001, junto con la caracterización del hábitat. Se seleccionaron tres localidades en este segmento fluvial y se compararon con una localidad de referencia localizada aguas arriba. Se concluye que la presencia de varias estructuras como los azudes sumergidos y enrocamentos, promovió la diversidad, derivado de la complejidad física que ellos introdujeron en el sistema. Las riadas dramáticas que ocurrieron en el invierno de 2000/01 también causaron cambios sustanciales en la dinámica fluvial y en los hábitats: la gran cantidad de sólidos en suspensión transportada dio lugar a un substrato constituido por materiales finos inestables, y al empobrecimiento biológico consecuente. Sin embargo, ambas comunidades mostraron una elevada resiliencia a estos eventos, quedando las diferencias interanuales ocultadas por las diferencias estaciónales en las comunidades de invertebrados

Leaf litter decomposition in western Iberian forested wetlands : lentic versus lotic response

Leaf litter breakdown is frequently used to measure both structural and functional integrity in aquatic ecosystems. Forested wetlands are interface systems that received little attention, especially in the Iberian Peninsula. The present study compares the decomposition of alder and willow in two biotopes (lentic and lotic) located in two different sites (Caxarias and Alpiarça). Litterbags were used to compare decomposition among the different treatments. Throughout decay, dry weight loss, nitrogen and phosphorus content, microbial community physiological profiles, microbial and macro-invertebrate colonization were measured at days 2, 4, 8, 16, 32 and 64. Decomposition rates ranged from intermediate to rapid for alder (0.006 day−1 to 0.0338 day−1) and slow to rapid for willow (0.0024 day−1 to 0.0272 day−1), depending on site and biotopes type. The combined effects biotope × time was significant for heterotrophs (P < 0.05), molds (P < 0.05) and yeasts (P < 0.001). The analysis of average well colour development (AWCD), richness (R) and Shannon-Wiener index (H') based on the oxidation of carbon and nitrogen sources by the microbial community, showed differences between the two biotopes, lotic and lentic, and sites. These differences were also shown by the principal component analysis (PCA). Moreover, the macroinvertebrate communities clearly distinguished between lentic and lotic systems. The invertebrates belonging to Plecoptera, Ephemeroptera and Trichoptera were absent from lentic habitats.La descomposición de hojarasca se utiliza frecuentemente para medir la integridad estructural y funcional en los sistemas acuáticos. Los humedales arbolados son sistemas de transición que han recibido escasa atención especialmente en la Península Ibérica. El presente trabajo compara la descomposición de la hojarasca de aliso y sauce en dos sistemas (lenítico y lótico) situados en dos localidades (Caxarias y Alpiarça). Se utilizaron bolsas para hojarasca para comparar la descomposición entre los diferentes tratamientos. Se determinaron las pérdidas de peso seco, contenido en N y P en el detritus vegetal, perfiles fisiológicos de la comunidad microbiana, la colonización microbiana y de macroinvertebrados a los 2, 4, 8, 16, 32 y 64 días del experimento. Las tasas de descomposición variaron de intermedias a rápidas para el aliso (0.006 día−1 a 0.0338 día−1) y de lentas a rápidas para el sauce (0.0024 día−1 a 0.0272 día−1), dependiendo de la localidad de muestreo y del tipo de sistema. Los efectos combinados sistema × tiempo resultaron significativos para los heterótrofos totales (p < 0.05), hongos filamentosos (p < 0.05) y levaduras (p < 0.001). El análisis del desarrollo medio del color (AWCD), la riqueza (R) y el índice de Shannon-Wiener (H') basados en la oxidación de las fuentes de nitrógeno y carbono por parte de la comunidad microbiana, mostraron diferencias entre los dos sistemas, lótico y lenítico y entre las localidades de muestreo. Estas diferencias se pusieron también de manifiesto en el análisis de componentes principales (PCA). Además, las comunidades de macroinvertebrados claramente diferenciaron los sistemas leníticos de los lóticos. Se observó que en los sistemas leníticos los organismos pertenecientes a Plecoptera, Ephemeroptera y Trichoptera estaban ausentes

Adapting and adopting River Habitat Survey : problems and solutions for fluvial hydromorphological assessment in Portugal

The Water Framework Directive (WFD), which established the use of hydromorphological quality elements to assess the ecological status of water bodies, has influenced the purpose and content of several European methods for characterizing physical structure and assessing habitat quality in rivers. The River Habitat Survey (RHS) is a WFD compliant method developed in the UK and follows rapid and simple survey procedures using a standardised approach to characterize the physical habitat and evaluate hydromorphological quality. In Portugal, RHS was adopted for WFD purposes due to its successful long term application across the UK and other European countries. Even so, an effort was made to adapt the RHS to Portuguese regional and river characteristics, in order to accurately record habitat features, assess habitat quality and comply with legal requirements. This paper describes the constraints, adaptations, state of the art and way forward for a successful RHS implementation in Portugal. Constraints concerning the application of RHS to Mediterranean rivers are strongly related to natural hydromorphological processes, namely annual and inter-annual flow variability, which is a potential source of covariance with anthropogenic pressures. This leads to difficulties in recognizing and accurately recording some RHS features. Adaptations to RHS were introduced for survey guidelines, recording procedures and improved definitions of habitat features. Additional modifications were prepared in different sections of RHS field form to reflect Portuguese river features and incorporate components required by the WFD.La Directiva Marco del Agua (DMA), que estableció el uso de indicadores de calidad hidromorfológicos para evaluar el estado ecológico de las masas de agua, ha influido en la finalidad y el contenido de varios métodos europeos para la caracterización de la estructura física y la evaluación de la calidad del h'abitat en los ríos. El River Habitat Survey (RHS) es un método compatible con la DMA desarrollado en el Reino Unido y sigue los procedimientos de encuesta rápida y sencilla utilizando un método estándar para caracterizar el hábitat físico y evaluar la calidad hidromorfológa. En Portugal, el RHS fue adoptado a efectos de la DMA debido a su exitosa aplicación a largo plazo en el Reino Unido y otros países europeos. Aun así, se hizo un esfuerzo para adaptar el RHS a las características regionales y de los ríos de Portugal, con el fin de registrar con precisión las características del hábitat, evaluar la calidad del hábitat y cumplir con los requisitos legales. Este artículo describe las limitaciones, las adaptaciones, el estado de implementacion y la manera para una implementación exitosa de RHS en Portugal. Las restricciones relativas a la aplicación de RHS a los ríos del Mediterráneo están fuertemente relacionadas con procesos hidromorfológicos naturales, como es la variabilidad del flujo anual e interanual, la cual es una fuente potencial de covarianza con presiones antropogénicas. Esto lleva a dificultades para reconocer y registrar con precisión algunas de las caracter'ısticas del RHS. Se han introducido adaptaciones al RHS en las directrices de muestreo, en los procedimientos de registro y se han mejorado algunas definiciones de ciertas características del hábitat. Otras modificaciones adicionales se han realizado en diferentes secciones del formulario de campo del RHS para reflejar las características de los ríos por tugueses y ciertas componentes requeridas por la DMA

Effects of landscape metrics and land-use variables on macroinvertebrate communities and habitat characteristics

The growing number of studies establishing links between stream biota, environmental factors and river classification has contributed to a better understanding of fluvial ecosystem function. Environmental factors influencing river systems are distributed over hierarchically organised spatial scales. We used a nested hierarchical sampling design across four catchments to assess how benthic macroinvertebrate community composition and lower spatial scale habitat descriptors were shaped by landscape and land-use patterns. We found that benthic macroinvertebrate community structure and composition varied significantly from catchment to habitat level. We assessed and identified fractal metrics of landscape descriptors capable of explaining compositional and functional change in the benthic faunal indicators and compared them with the traditional variables describing land use and reach level habitat descriptors within a 1 km radius of each sampling site. We found that fractal landscape metrics were the best predictor variables for benthic macroinvertebrate community composition, function, instream habitat and river corridor characteristics.El creciente número de estudios que relacionan la biota fluvial, los factores ambientales y la clasificación de los ríos, ha contribuido a comprender el funcionamiento de los ecosistemas fluviales. La organización de los factores ambientales fluviales es entendida, en la actualidad, como una jerarquía de factores con varias escalas espaciales. Para evaluar cómo la composición de los macroinvertebrados bentónicos y las características del hábitat a escala local son afectadas por el uso del paisaje y del suelo, se siguió un diseño de muestreo jerárquico en cuatro cuencas. Hemos verificado que la estructura y composición de las comunidades de macroinvertebrados bentónicos varió significativamente desde la escala de cuenca hasta la del hábitat. Fueron evaluadas e identificadas métricas fractales del paisaje que podrían explicar los cambios en la composición y funcionalidad de la fauna bentónica y se ha comparado también con la influencia de las tradicionales variables de usos del suelo y descriptores del hábitat al nivel del tramo, en un círculo de 1 km de radio alrededor de cada tramo. Encontramos que las métricas fractales del paisaje fueron las mejores variables predictoras de la composición y funcionalidad de las comunidades de macroinvertebrados y de las características del hábitat en el cauce y del corredor fluvial

A preliminary fishery quality index for Portuguese streams

There is a need to quantify the multivariate quality of a recreational fishery at the site scale to better communicate the relative quality among sites to the public and anglers. Borrowing on the general approach of multimetric indices of biotic integrity (IBIs), we developed fishery quality indices (FQIs) from species quality indices (SQIs) based on measures of fish abundance and size structure for northern and central Portuguese streams. Our FQIs showed regional patterns indicating a range in fishery quality. Higher coldwater FQI scores were mostly found in the northwestern (Minho and Lima), northeastern Douro, and northern Tagus basins. Higher warmwater FQI scores occurred in the eastern Tagus basin. The species that contributed the most to warmwater FQI scores were largemouth bass Micropterus salmoides, pumpkinseed Lepomis gibbosus, the cyprinid Luciobarbus bocagei, chubs Squalius carolitertii and S. pyrenaicus, and nases Pseudochondrostoma duriense and P. polylepis. The chubs, nases, and brown trout Salmo trutta contributed the most to coldwater FQI scores. As expected, our indices were correlated with river size and with disturbance at the catchment, segment, and site scales. Regression models for separate coldwater and warmwater FQIs were stronger than those for the individual SQIs and for an all-site FQI. The correlation was positive between the coldwater FQI and a coldwater IBI but negative between the warmwater FQI and warmwater IBIs. The proposed FQIs offer a quantitative approach for assessing relative fishery quality among sites and for making regional assessments given an appropriate study design. The component SQIs and SQI metrics of the FQIs can be disassociated to determine the population and species characteristics most affected by various environmental variables

Detailed dimethylacetal and fatty acid composition of rumen content from lambs fed lucerne or concentrate supplemented with soybean oil

Articles in International JournalsLipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/ acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18:1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18:2n26 and 18:3n23. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18:0 might be produced during biohydrogenation of the 18:3n23

Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions

At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP)(1). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed(2-6). Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions(7), is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions(8,9), but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results(10,11), indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed.Peer reviewe

Measurement of azimuthal correlations of D mesons with charged particles in pp collisions at √s=7 TeV and p-Pb collisions at √sNN=5.02 TeV

The azimuthal correlations of D mesons with charged particles were measured with the ALICE apparatus in pp collisions at root s = 7 TeV and p-Pb collisions at root sNN = 5.02 TeV at the Large Hadron Collider. D-0, D+, and D*+ mesons and their charge conjugates with transverse momentum 3 0.3 GeV/c. The yield of charged particles in the correlation peak induced by the jet containing the D meson and the peak width are compatible within uncertainties in the two collision systems. The data are described within uncertainties by Monte-Carlo simulations based on PYTHIA, POWHEG, and EPOS 3 event generators.Peer reviewe