11 resultados para Mason, David, 1726-1794.

em Aquatic Commons


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This report summarizes the results of a characterization of chemical contaminants in the sediments in southwest Puerto Rico. The report is part of a project to integrate various analytical specialties to assess linkages between chemical contaminants and the condition of coral reefs. In this phase of the project, over 120 chemical contaminants were analyzed in sediments collected, including a number of organic (e.g., hydrocarbons), inorganic (e.g., metals), and biological (bacterial) compounds/analytes. The report also provides a preliminary analysis of the association between sediment contaminants and coral species richness. Overall, the levels of chemical contaminants in the study area between Guanica Bay and the town of La Parguera were fairly low. At most of the sites sampled, particularly adjacent to the town of La Parguera, concentrations of organic and inorganic contaminants were below the median values from NOAA’s National Status and Trends Program, which monitors the Nation’s coastal and estuarine waters for chemical contaminants. Elevated levels of a number of contaminant classes were seen at the two sites sampled within Guanica Bay. An initial analysis of modeled PAH (hydrocarbon) data and coral species richness (reef building species) indicated a strong negative correlation between the presence of PAHs in the sediments and coral species richness. Additional work is needed to assess possible reasons for this observed pattern. (PDF contains 126 pages).

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The distribution, abundance, age and growth, the food and feeding habits, condition factor and reproduction of Hepsetus odoe in the Epie Creek Floodplain (Nigeria) was studied. H. odoe occur in the creek, swamp channel and lake. It is a very common, abundant and one of the major commercial species. A total of 457 specimens weighing 76.90 kg were caught during the period of investigation. The catches were more abundant in the dry season than in the wet season. The total length ranged from 10 cm to 46 cm while the weight varied between 50 g and 900 g. Six distinct components or year classes were observed using Bhattacharya's method. A growth exponential value 'b' was 3.35 with condition factor, 'k' values ranging from 0.69 to 0.83. The main diets of Hepsetus odoe were fish, including crustaceans (shrimps) and insects. The mean fecundity was 6060 plus or minus 358 eggs (range 2,769 to 6.667 eggs). The ova diameter of H. odoe was found to range from 2.2 mm to 2.6 mm with overall mean = 2.4 plus or minus 0.1)

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John Otterbein Snyder (1867–1943) was an early student of David Starr Jordan at Stanford University and subsequently rose to become an assistant professor there. During his 34 years with the university he taught a wide variety of courses in various branches of zoology and advised numerous students. He eventually mentored 8 M.A. and 4 Ph.D. students to completion at Stanford. He also assisted in the collection of tens of thousands of fish specimens from the western Pacific, central Pacific, and the West Coast of North America, part of the time while stationed as “Naturalist” aboard the U.S. Fish Commission’s Steamer Albatross (1902–06). Although his early publications dealt mainly with fish groups and descriptions (often as a junior author with Jordan), after 1910 he became more autonomous and eventually rose to become one of the Pacific salmon, Oncorhynchus spp., experts on the West Coast. Throughout his career, he was especially esteemed by colleagues as “a stimulating teacher,” “an excellent biologist,” and “a fine man.

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NOAA’s National Status and Trends Program (NS&T) collected oyster tissue and sediments for quantification of polycyclic aromatic hydrocarbons (PAHs) and petroleum associated metals before and after the landfall of oil from the Deepwater Horizon incident of 2010. These new pre- and post- landfall measurements were put into a historical context by comparing them to data collected in the region over three decades during Mussel Watch monitoring. Overall, the levels of PAHs in both sediment and oysters both pre- and post-landfall were within the range of historically observed values for the Gulf of Mexico. Some specific sites did have elevated PAH levels. While those locations generally correspond to areas in which oil reached coastal areas, it cannot be conclusively stated that the contamination is due to oiling from the Deepwater Horizon incident at these sites due to the survey nature of these sampling efforts. Instead, our data indicate locations along the coast where intensive investigation of hydrocarbon contamination should be undertaken. Post-spill concentrations of oil-related trace metals (V, Hg, Ni) were generally within historically observed ranges for a given site, however, nickel and vanadium were elevated at some sites including areas in Mississippi Sound and Galveston, Terrebonne, Mobile, Pensacola, and Apalachicola Bays. No oyster tissue metal body burden exceeded any of the United States Food and Drug Administration’s (FDA) shellfish permissible action levels for human consumption.

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Guánica Bay is a major estuary on the southwest coast of Puerto Rico. Significant coral reef ecosystems are present outside the bay. These valuable habitats may be impacted by transport of sediments, nutrients and contaminants from the watershed, through the bay and into the offshore waters. The National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Coastal Ocean Science (NCCOS), in consultation with local and regional experts, conducted an interdisciplinary assessment of coral reef ecosystems, contaminants, sedimentation rates and nutrient distribution patterns in and around Guánica Bay. This work was conducted using many of the same protocols as ongoing monitoring work underway elsewhere in the U.S. Caribbean and has enabled comparisons among coral reef ecosystems between this study and other locations in the region. This characterization of Guánica marine ecosystems establishes benchmark conditions that can be used for comparative documentation of future change, including possible negative outcomes due to future land use change, or improvement in environmental conditions arising from management actions. This report is organized into six chapters that represent a suite of interrelated studies. Chapter 1 provides a short introduction to the study area. Chapter 2 is focused on biogeographic assessments and benthic mapping of the study area, including new surveys of fish, marine debris and reef communities on hardbottom habitats in the study area. Chapter 3 quantifies the distribution and magnitude of a suite of contaminants (e.g., heavy metals, PAHs, PCBs, pesticides) in both surface sediments and coral tissues. Chapter 4 presents results of sedimentation measurements in and outside of the bay. Chapter 5 examines the distribution of nutrients in in the bay, offshore from the bay and in the watershed. Chapter 6 is a brief summary discussion that highlights key findings of the entire suite of studies.

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Coral ( Porites astreoides ) from eight sites in southwest Puerto Rico were analyzed for approximately 150 chemical contaminants, to provide a preliminary characterization of environmental contamination in the corals, and assess the relationships between chemical contamination in corals and adjacent sediments. Overall, the concentration of PAHs (polycyclic aromatic hydrocarbons) and PCBs (polychlorinated biphenyls) detected in the limited number of coral samples collected were comparable to concentrations found in sediments. However, the concentration of a chemical contaminant (e.g., PAHs) in the corals at a site was often different from what was found in adjacent sediments. The level of PCBs and DDT (dichlorodiphenyltrichloroethane) in the corals appeared higher just outside of Guanica Bay, and there was some evidence of a downstream concentration gradient for these two contaminant classes. The trace elements copper and zinc were frequently detected in Porites astreoides , and the concentrations were usually comparable to those found in adjacent sediments. Chromium was an exception in that it was not detected in any of the coral samples analyzed, although it was detected in all of the sediment samples.

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This report presents an initial characterization of chemical contamination in coral tissues (Porites astreoides) from southwest Puerto Rico. It is the second technical report from a project to characterize chemical contaminants and assess linkages between contamination and coral condition. The first report quantified chemical contaminants in sediments from southwest Puerto Rico. This document summarizes the analysis of nearly 150 chemical contaminants in coral tissues. Although only eight coral samples were collected, some observations can be made on the correlations between observed tissue and sediment contaminant concentrations. The concentrations of polycyclic aromatic hydrocarbons (PAHs), typically associated with petroleum spills and the combustion of fossil fuels, and polychlorinated biphenyls (PCBs) in the coral tissues were comparable to concentrations found in adjacent sediments. However, the concentration of a chemical contaminant (e.g., PAHs) in the coral tissues at a particular site was not a good predictor of what was in the adjacent sediments. In addition, the types of PAHs found in the coral tissues were somewhat different (higher ratios of alkylated PAHs) than in sediments. The levels of PCBs and DDT in coral tissues appeared higher just outside of Guanica Bay, and there was evidence of a downstream concentration gradient for these two contaminant classes. The trace elements copper, zinc and nickel were frequently detected in coral tissues, and the concentration in the corals was usually comparable to that found in adjacent sediments. Chromium was an exception in that it was not detected in any of the coral tissues analyzed. Additional work is needed to assess how spatial patterns in chemical contamination affect coral condition, abundance and distribution.

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Esta serie de ProBiota tiene como propósito mostrar diferentes expresiones artísticas relacionadas con la Ictiología nacional y regional, generadas en diferentes épocas y que surgen por diversas motivaciones personales que, en algún caso, muestran casi con exactitud a los modelos que inspiraron la obra, en otras, por lo contrario, responden a la imaginación y creatividad del autor. En este núnero de su Serie Arte y Sociedad, se han recopilado las magnificas ilustraciones de David Almirón que fueron incluidas en la obra “Para un bestiario de Indias” de Alberto M. Salas editada en 1968 y las que aquí son reproducidas con el número de la página donde están ubicadas Estos creadores con particular estilo nos describen parte del “abanico zoológico” del “Nuevo Mundo”. Invito a quiénes no lo hayan hecho, colegas, estudiosos y profanos, a dar una lectura a este libro, puesto que no me queda duda que saldrán enriquecidos en todo sentido. Sólo me resta convocar a quienes quieran sumarse a esta iniciativa de ProBiota, se acerquen con sus aportes para consolidar esta idea, ya que podría ser otro instrumento de difusión del conocimiento de nuestra disciplina a los diferentes estamentos de la sociedad.

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This study was aimed to analyze the annual reproductive cycle of the freshwater crab Paratelphusa spinigera (Wood Mason, 1871). P. spinigera breeds only once in a year; hence, it is a monovoltine species. Gonad maturation, changes in abdomen shape, size and female maturity index (FMI) marked the onset of sexual maturity of female P. spinigera. The occurrence of berried females marked the onset of breeding season. The fecundity of P. spinigera ranged from 533 to 1306 in number, with an average of 699.11 ± 217.38. The correlation of fecundity with carapace width and body weight was also found to be positively significant (r = 0. 780 and 0.933, respectively). The eggs were carried on the pleopods and nurtured for approximately 30-35 days, until the eggs hatch, showing perfect maternal care. The FMI values ranging between 0.70 and 0.80 represented immature stage of gonadal development. When the FMI ranged from 0.91 to 1.00, all stages of gonadal development, i.e. developing, maturing and mature stages were observed. The females with fully ripe ovary had FMI values greater than 1.00.