979 resultados para Aquatic resources
Resumo:
Environmental quality monitoring of water resources is challenged with providing the basis for safeguarding the environment against adverse biological effects of anthropogenic chemical contamination from diffuse and point sources. While current regulatory efforts focus on monitoring and assessing a few legacy chemicals, many more anthropogenic chemicals can be detected simultaneously in our aquatic resources. However, exposure to chemical mixtures does not necessarily translate into adverse biological effects nor clearly shows whether mitigation measures are needed. Thus, the question which mixtures are present and which have associated combined effects becomes central for defining adequate monitoring and assessment strategies. Here we describe the vision of the international, EU-funded project SOLUTIONS, where three routes are explored to link the occurrence of chemical mixtures at specific sites to the assessment of adverse biological combination effects. First of all, multi-residue target and non-target screening techniques covering a broader range of anticipated chemicals co-occurring in the environment are being developed. By improving sensitivity and detection limits for known bioactive compounds of concern, new analytical chemistry data for multiple components can be obtained and used to characterise priority mixtures. This information on chemical occurrence will be used to predict mixture toxicity and to derive combined effect estimates suitable for advancing environmental quality standards. Secondly, bioanalytical tools will be explored to provide aggregate bioactivity measures integrating all components that produce common (adverse) outcomes even for mixtures of varying compositions. The ambition is to provide comprehensive arrays of effect-based tools and trait-based field observations that link multiple chemical exposures to various environmental protection goals more directly and to provide improved in situ observations for impact assessment of mixtures. Thirdly, effect-directed analysis (EDA) will be applied to identify major drivers of mixture toxicity. Refinements of EDA include the use of statistical approaches with monitoring information for guidance of experimental EDA studies. These three approaches will be explored using case studies at the Danube and Rhine river basins as well as rivers of the Iberian Peninsula. The synthesis of findings will be organised to provide guidance for future solution-oriented environmental monitoring and explore more systematic ways to assess mixture exposures and combination effects in future water quality monitoring.
Resumo:
Sampling was conducted from March 24 to August 5 2010, in the fjord branch Kapisigdlit located in the inner part of the Godthåbsfjord system, West Greenland. The vessel "Lille Masik" was used during all cruises except on June 17-18 where sampling was done from RV Dana (National Institute for Aquatic Resources, Denmark). A total of 15 cruises (of 1-2 days duration) 7-10 days apart was carried out along a transect composed of 6 stations (St.), spanning the length of the 26 km long fjord branch. St. 1 was located at the mouth of the fjord branch and St. 6 was located at the end of the fjord branch, in the middle of a shallower inner creek . St. 1-4 was covering deeper parts of the fjord, and St. 5 was located on the slope leading up to the shallow inner creek. Mesozooplankton was sampled by vertical net tows using a Hydrobios Multinet (type Mini) equipped with a flow meter and 50 µm mesh nets or a WP-2 net 50 µm mesh size equipped with a non-filtering cod-end. Sampling was conducted at various times of day at the different stations. The nets were hauled with a speed of 0.2-0.3 m s**-1 from 100, 75 and 50 m depth to the surface at St. 2 + 4, 5 and 6, respectively. The content was immediately preserved in buffered formalin (4% final concentration). All samples were analyzed in the Plankton sorting and identification center in Szczecin (www.nmfri.gdynia.pl). Samples containing high numbers of zooplankton were split into subsamples. All copepods and other zooplankton were identified down to lowest possible taxonomic level (approx. 400 per sample), length measured and counted. Copepods were sorted into development stages (nauplii stage 1 - copepodite stage 6) using morphological features and sizes, and up to 10 individuals of each stage was length measured.
Resumo:
Sampling was conducted from March 24 to August 5 2010, in the fjord branch Kapisigdlit located in the inner part of the Godthåbsfjord system, West Greenland. The vessel "Lille Masik" was used during all cruises except on June 17-18 where sampling was done from RV Dana (National Institute for Aquatic Resources, Denmark). A total of 15 cruises (of 1-2 days duration) 7-10 days apart was carried out along a transect composed of 6 stations (St.), spanning the length of the 26 km long fjord branch. St. 1 was located at the mouth of the fjord branch and St. 6 was located at the end of the fjord branch, in the middle of a shallower inner creek . St. 1-4 was covering deeper parts of the fjord, and St. 5 was located on the slope leading up to the shallow inner creek. Mesozooplankton was sampled by vertical net tows using a Hydrobios Multinet (type Mini) equipped with a flow meter and 50 µm mesh nets or a WP-2 net 50 µm mesh size equipped with a non-filtering cod-end. Sampling was conducted at various times of day at the different stations. The nets were hauled with a speed of 0.2-0.3 m s**-1 from 100, 75 and 50 m depth to the surface at St. 2 + 4, 5 and 6, respectively. The content was immediately preserved in buffered formalin (4% final concentration). All samples were analyzed in the Plankton sorting and identification center in Szczecin (www.nmfri.gdynia.pl). Samples containing high numbers of zooplankton were split into subsamples. All copepods and other zooplankton were identified down to lowest possible taxonomic level (approx. 400 per sample), length measured and counted. Copepods were sorted into development stages (nauplii stage 1 - copepodite stage 6) using morphological features and sizes, and up to 10 individuals of each stage was length measured.
Resumo:
Sampling was conducted from March 24 to August 5 2010, in the fjord branch Kapisigdlit located in the inner part of the Godthåbsfjord system, West Greenland. The vessel "Lille Masik" was used during all cruises except on June 17-18 where sampling was done from RV Dana (National Institute for Aquatic Resources, Denmark). A total of 15 cruises (of 1-2 days duration) 7-10 days apart was carried out along a transect composed of 6 stations (St.), spanning the length of the 26 km long fjord branch. St. 1 was located at the mouth of the fjord branch and St. 6 was located at the end of the fjord branch, in the middle of a shallower inner creek . St. 1-4 was covering deeper parts of the fjord, and St. 5 was located on the slope leading up to the shallow inner creek. Mesozooplankton was sampled by vertical net tows using a Hydrobios Multinet (type Mini) equipped with a flow meter and 50 µm mesh nets or a WP-2 net 50 µm mesh size equipped with a non-filtering cod-end. Sampling was conducted at various times of day at the different stations. The nets were hauled with a speed of 0.2-0.3 m s**-1 from 100, 75 and 50 m depth to the surface at St. 2 + 4, 5 and 6, respectively. The content was immediately preserved in buffered formalin (4% final concentration). All samples were analyzed in the Plankton sorting and identification center in Szczecin (www.nmfri.gdynia.pl). Samples containing high numbers of zooplankton were split into subsamples. All copepods and other zooplankton were identified down to lowest possible taxonomic level (approx. 400 per sample), length measured and counted. Copepods were sorted into development stages (nauplii stage 1 - copepodite stage 6) using morphological features and sizes, and up to 10 individuals of each stage was length measured.
Resumo:
Curimatídeos do gênero Cyphocharax Fowler, 1906 distribuem-se amplamente nas bacias hidrográficas da América do Sul, contudo essa ampla distribuição inequivale a quantidade de trabalhos relacionados ao gênero. Visto isso, objetivou-se contribuir ao conhecimento de Cyphocarax gouldingi (Vari, 1992) através da caracterização morfométrica de indivíduos coletados na microbacia do rio Praquiquara, localizado no médio Apeú, Amazônia Oriental. Para a determinação morfométrica da espécie, utilizou-se o software Adobe Photoshop CS6 Extended, mensurando os respectivos caracteres merísticos: comprimentos total, padrão, zoológico, cabeça e focinho, a medida da altura e o diâmetro do olho de 178 exemplares capturados entre os meses setembro (2014) e maio (2015). Verificou-se uma correlação forte positiva e alometria negativa, entre o comprimento total e as demais medidas externas, e observou a importância do rio Praquiquara durante o ciclo de vida da espécie. Conclui-se que as medidas morfométricas de C. gouldingi (1) satisfazem a estimação de comprimento total e (2) possibilitam o estudo sobre a dinâmica de crescimento da espécie estudada.
Resumo:
La nitrificación-desnitrificación es el proceso biológico tradicional para la remoción de nitrógeno de las aguas residuales (Ruiz G. et al., 2006a), siendo fundamental ya que contribuye a controlar la eutroficación de los cuerpos receptores. Debido al deterioro que sobre la disponibilidad de los recursos han ejercido las actividades antropogénicas, es necesario orientar el tratamiento de las aguas residuales hacia tecnologías que ofrezcan el mayor grado de sustentabilidad, planteando innovaciones en el tratamiento. El presente proyecto de tesis doctoral versa sobre el estudio de la influencia de la relación C/N en la desnitrificación y metanogénesis de aguas residuales urbanas en un reactor anaeróbico de lecho fluidizado inverso (RLFI). Previamente a la realización de las pruebas experimentales de variación de la relación C/N, se llevó a cabo la etapa de arranque del RLFI la cual se inició en modo batch, favoreciendo la formación y adhesión de biopelícula al medio de soporte utilizado (Extendosphere). Después, sobrevino la operación en modo continuo desde una carga volumétrica aplicada (CVA) de 0.5 g DQOs/L⋅d hasta alcanzar 4 g DQOs/L⋅d, carga volumétrica a la cual se logró la plena estabilización del reactor, siendo la alta variabilidad de la concentración de DQOs en el agua residual urbana de alimentación, la principal problemática que ocasionó retrasos en la estabilidad del reactor. A una CVA de 4 g DQOs/L⋅d en estado estacionario, el valor mínimo de eficiencia de remoción de DQOs fue del 32.36% y el máximo de 66.99%. En estas condiciones el porcentaje de metano presente en el biogás producido tuvo un valor medio de 85.57 ± 2.93%, siendo un valor alto comparado con otros porcentajes de metano encontrados en la digestión anaerobia de aguas residuales urbanas. El YCH4 tuvo un valor medio de 0.316 ± 0.110 LCH4/g DQOrem⋅día. Los porcentajes de metanización variaron en el rango de 20.50 a 100%, registrándose un valor medio de 73.42 ± 25.63%. La considerable variabilidad en el porcentaje de metanización se debió principalmente a que se presentaron eventos de lavado de soporte colonizado, lo cual propició que las actividades metabólicas fueran orientadas hacia formación de biopelícula (anabolismo) en vez de estar dirigidas hacia producción de metano (catabolismo). En relación a los ensayos con variación de la relación C/N, se manejaron relaciones DQOs/N-NO3 en el rango de 1.65 a 21.1 g DQOs/g N-NO3. La tasa de remoción anaerobia de DQOs se incrementó con la concentración de sustrato en una relación casi lineal, ajustándose a una cinética de primer orden, lo que regularmente se presenta a concentraciones bajas de sustrato. La eficiencia del proceso de desnitrificación fue por lo regular alta, incrementándose ligeramente con la concentración de DQOs en el influente, con valores en el rango de 73.8 a 99.1%. Por otra parte, la tasa de remoción por metanogénesis se incrementó con la concentración relativa de sustrato (es decir, a mayores relaciones DQOs/N-NO3), siendo más sensitiva la metanogénesis a la concentración relativa de sustrato que la desnitrificación. Conforme aumentó la relación DQOs/N-NO3, la desnitrificación, de ser la ruta metabólica principal de utilización de la materia orgánica (comparada con la metanización), empezó a combinarse con la metanización. De manera evidente, a las relaciones DQOs/N-NO3 probadas, se manifestaron más las actividades desnitrificantes, quedando reflejadas por el alto porcentaje de utilización de la DQOs removida hacia la desnitrificación. La relación experimental DQOs/N-NO3 a la cual se pudiera haber cumplido con el requerimiento de materia orgánica (en términos de DQOs) para la desnitrificación de nitratos en las aguas residuales urbanas tratadas resultó aproximadamente ser igual a 7.1 g DQOs/g N-NO3. A una CVA de 4 g DQOs/L⋅d, se obtuvo un diámetro promedio máximo de soporte colonizado igual a 266.106 ± 69.279 μm aunque, hay que indicarlo, se presentaron fluctuaciones, las cuales se reflejaron también en el espesor de la biopelícula, el cual tuvo un valor máximo de 50.099 μm y un valor promedio de 37.294 ± 11.199 μm. Estas fluctuaciones pudieron deberse a la existencia de corrientes preferenciales dentro del reactor, las cuales no permitieron un acceso equitativo del sustrato a todo el lecho. Nitrification-denitrification is the traditional biological process for nitrogen removal from wastewaters (Ruiz G. et al., 2006a), being fundamental since it contributes to control the eutrophication of the receiving waters. Due to the deterioration that on the availability of the aquatic resources the anthropogenic activities have exerted, it is necessary to orient the treatment of wastewaters towards technologies that offer the greater degree of sustainability, raising innovations in the treatment. This work studied the influence of C/N ratio on denitrification and methanogenesis of urban wastewaters in an inverse fluidized bed reactor (IFBR). Previously to the accomplishment of the experimental tests with variation of C/N ratio, the start up of the IFBR was carried out in batch way, encouraging the formation and adhesion of biofilm to Extendosphere, which it was used as support. The operation in continuous way carried out from an organic loading rate (OLR) of 0.5 g CODs/L ∙ d to 4 g CODs/L ∙ d, when the steady-state was reached. The high variability of the CODs of the urban wastewaters caused delays in the stability of the reactor. Once stationary state was reached, the removal efficiency of CODs ranged from 32.36 to 66.99% to 4 g CODs/L ∙ d. In these conditions the percentage of methane in produced biogas had an average value of 85.57 ± 2.93%, being a high value compared with other studies treating anaerobically urban wastewaters. The YCH4 had an average value of 0.316 ± 0.110 LCH4/g CODrem ∙ d. The percentage of methanisation ranged from 20.50 to 100%, with an average value of 73.42 ± 25.63%. The considerable variability in the methanisation percentage occurred mainly due events of wash-out of colonized support, which caused that the metabolic activities were oriented towards formation of biofilm (anabolism) instead of methane production (catabolism). Concerning the tests with variation of C/N ratio, CODs/NO3-N ratios from 1.65 to 21.1 g CODs/g NO3-N were proved. The CODs anaerobic removal rate increased with the substrate concentration in an almost linear relation, adjusting to a kinetic of first order, which regularly appears to low concentrations of substrate. Efficiency of the denitrification process was regularly high, and it increased slightly with the CODs concentration in the influent, ranging from 73.8 to 99.1%. On the other hand, the CODs removal rate by methanogenesis increased with the substrate relative concentration (e.g., to greater CODs/NO3-N ratios), being more sensitive the methanogenesis to the substrate relative concentration that the denitrification. When the CODs/NO3-N ratio increased, the denitrification, of being the main metabolic route of use of the organic matter (compared with the methanogenesis), began to be combined with the methanogenesis. Definitively, to the proven CODs/NO3-N ratios the denitrification processes were more pronounced, being reflected by the high percentage of use of the removed CODs towards denitrification. The experimental CODs/NO3-N ratio to which it was possible to have been fulfilled the requirement of organic matter (in terms of CODs) for the denitrification of nitrates in urban wastewaters turned out to be approximately 7.1 g CODs/g NO3-N. It was obtained a maximum average diameter of colonized support of 266.106 ± 69.279 μm to 4 g CODs/L ∙ d, although it is necessary to indicate that appeared fluctuations in the thickness of biofilm, which had a maximum value of 50.099 μm and an average value of 37.294 ± 11.199 μm. These fluctuations could be due to the existence of preferential currents within the reactor, which did not allow an equitable access of the substrate to all the bed.
Resumo:
New carbon and nitrogen stable isotope values for human remains dating to the mid-Upper Paleolithic in Europe indicate significant amounts of aquatic (fish, mollusks, and/or birds) foods in some of their diets. Most of this evidence points to exploitation of inland freshwater aquatic resources in particular. By contrast, European Neandertal collagen carbon and nitrogen stable isotope values do not indicate significant use of inland aquatic foods but instead show that they obtained the majority of their protein from terrestrial herbivores. In agreement with recent zooarcheological analyses, the isotope results indicate shifts toward a more broad-spectrum subsistence economy in inland Europe by the mid-Upper Paleolithic period, probably associated with significant population increases.
Resumo:
"#31230"--Colophon.
Resumo:
When using this book, students will become familiar with the aquatic resources of Illinois. The information and activities can help you meet the following Illinois learning standards: Mathematics 6.A.2, 6.B.1, 6.B.2, 6.B.3a, 6.C.1a, 6.C.2a, 6.C.3a; Science 11.A.1a, 11.A.1c, 11.A.1d, 11.A.2b, 11.A.2d, 11.A.3a, 11.A.3b, 11.A.3c, 11.A.3f; Social science 16.E.2a, 16.E.2c, 17.A.1a, 17.A.1b, 17.A.2a, 17.A.2b, 17.B.1a, 17.B.1b, 17.C.1a, 17.C.2b, 17.D.2b. For part of the activities an Illinois road map is needed.
Resumo:
"October 1987."
Resumo:
Dissertação de Mestrado, Gestão Empresarial, Faculdade de Economia, Universidade do Algarve, 2015
Resumo:
With some basic knowledge and minimum skill, a beginning angler can embark on a lifetime of fun, relaxation and camaraderie with other anglers. Discussed in this booklet are several styles of fishing, types of rods, reels, knots, baits, lures, freshwater fish and aquatic habitats. You’ll find tips to improve your skills and prepare you for a fun, exciting and successful fishing trip. You’ll also learn ways to protect your aquatic resources.
Resumo:
As part of ongoing studies concerned with the small-scale fisheries of the South of Portugal, experimental fishing was carried out with monofilament gillnets and small hook longlines within the same area. Sixty-two species were caught, of which 20 were common to both gears. Pronounced differences in terms of the relative importance of different species in the catches were observed. Size selection patterns also differed, with highly overlapped hook catch distributions and few species showing evidence for size selectivity. In contrast, strong selectivity was characteristic of species which tend to be "wedged" in gillnets. Whereas smaller stretched mesh sizes (particularly 40 and 50 mm) caught significant numbers of illegal sized fish, this was minimal in the longlines. Some implications for management are discussed.