72 resultados para 1995_12080748 Optics-10
Resumo:
This is a comparative survey of the Fish Populations of 10 West-Midlands Mere of Site of Special Scientific Interest Status. The meres of the Shropshire-Cheshire plain (West Midlands) comprise over 60 water bodies. Water quality in the meres ranges from naturally eutrophic to nutrient limited and some of them have received Site of Special Scientific Interest status (SSSIs). This survey was commissioned in order to obtain quantitative information on the fish fauna of selected SSSIs and evaluate the likely impact of fish on other species within the community. The current survey was concerned with 10 of the West Midlands’ meres, a cross section of sites was selected. Sites were widely distributed from Marton Pool in the south-western part of Shropshire to Tabley moat in Chesire. Meres varied in size, depth and nutrient status. All were to be sampled using the methods outlined. The report is divided into different sections for clarity and ease of reference. The materials and methods section provides an outline of the location and status of each mere and information on known fish species present. The results were considered individually and comparatively, relative abundance of fish, species present, their diet, sex, age, parasite burdens and growth. Inter-site comparisons were made using information derived from echo-soundings, growth rate, diet, and species abundance for each site. The final section will be in the form of a general discussion, comparative information from longer term studies, conclusions and recommendations.
Resumo:
The Biogeography Branch’s Sampling Design Tool for ArcGIS provides a means to effectively develop sampling strategies in a geographic information system (GIS) environment. The tool was produced as part of an iterative process of sampling design development, whereby existing data informs new design decisions. The objective of this process, and hence a product of this tool, is an optimal sampling design which can be used to achieve accurate, highprecision estimates of population metrics at a minimum of cost. Although NOAA’s Biogeography Branch focuses on marine habitats and some examples reflects this, the tool can be used to sample any type of population defined in space, be it coral reefs or corn fields.
Resumo:
This cruise report is a summary of a field survey conducted along the continental shelf of the northeastern Gulf of Mexico (GOM), encompassing 70,062 square kilometers of productive marine habitats located between the Mississippi Delta and Tampa Bay, August 13–21, 2010 on NOAA Ship Nancy Foster Cruise NF-10-09-RACOW. Synoptic sampling of multiple ecological indicators was conducted at each of 50 stations throughout these waters using a random probabilistic sampling design. At each station samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants (metals, pesticides, TPHs, PAHs, PCBs, PBDEs) in sediments and target demersal biota; sediment toxicity; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as depth, salinity, temperature, dissolved oxygen, turbidity, pH, CDOM fluorescence, sediment grain size, and organic carbon content. Discrete water samples were collected just below the sea surface, in addition to any deeper subsurface depths where there was an occurrence of suspicious CDOM fluorescence signals, and analyzed for total BTEX/TPH and carcinogenic PAHs using immunoassay test kits. Other indicators of potential value from a human-dimension perspective were also recorded, including presence of any vessels, oil rigs, surface trash, visual oil sheens in sediments or water, marine mammals, or noxious/oily sediment odors. The overall purpose of the survey was to collect data to assess the status of ecosystem condition and potential stressor impacts throughout the region, based on these various indicators and corresponding management thresholds, and to provide this information as a baseline for determining how such conditions may be changing with time. In addition to the original project goals, both the scientific scope and general location of this project are relevant to addressing potential ecological impacts of the Deepwater Horizon oil spill. While sample analysis is still ongoing, a few preliminary results and observations are reported here. A final report will be completed once all data have been processed.
Resumo:
El próximo septiembre se cumplen treinta años de la llamada Expedición Naútica-Cientifíca “R. P. Francisco Morillo” realizada en botes neumáticos por un grupo de personas de diferentes orígenes y entre los que se encontraban naturalistas y profesionales de las Ciencias Naturales. A nivel profesional fue una gran experiencia, ya que me permitió transitar por un ámbito geográfico de difícil acceso, con flora y fauna cuya referencia la tenía solo a través de textos. Por otra parte y mirado a la distancia, fue muy interesante el comportamiento humano del grupo. Entiendo que un sociólogo podría dar alguna interpretación, pero he visto de todo, actos de solidaridad, de mezquindad, egoísmo y de cierta locura, como por ejemplo, querer matar un yacaré por el simple hecho de que estaba en la playa tomando sol. En este caso, la suerte estuvo del lado de la noble bestia, ya que los involucrados en las Ciencias Naturales pudimos detener semejante barbaridad y hacer comprender a los de “gatillo fácil” que no había ningún sentido en lo que querían hacer. Irónicamente, entre otras cosas, este viaje tenía dentro de sus objetivos participar en un Congreso de Conservación… Los objetivos del viaje para los naturalistas, sólo se cumplieron en parte, ya que al principio de esta travesía comenzaron a suscitarse problemas, principalmente por las características del río, lo que dificultó, por falta de tiempo, la toma de muestras y las consiguientes observaciones. A nivel personal me queda la riqueza que me dio esta experiencia y el haber conocido a dos personas que me llamaron profundamente la atención. A nuestro baqueano José “Pipo” Marty, un hombre generoso y de una gran sabiduría. El otro fue Exequiel Martínez, al que conocí en el congreso que se realizaba en Resistencia y con quién, a partir de ese momento, me une un lazo afectivo que nace de un profundo respeto y admiración.
Resumo:
Artículo realizado para recordar la visita hace 10 años a Cuba de Jacques Ives Cousteau. Se identifican los resultados más relevantes a la luz del tiempo transcurrido y su significación.
Resumo:
EXTRACT (SEE PDF FOR FULL ABSTRACT): Zooplankton biomass and species composition have been sampled since 1985 at a set of standard locations off Vancouver Island. From these data, I have estimated multi-year average seasonal cycles and time series of anomalies from these averages.
Resumo:
This paper presents a resume of the work carried on the production of 10 million major carp fry by stocking at the rate of 10 million spawn per hectare in 38 nursery ponds covering 2.1 ha. water spread area at Khutelabhata fish seed farm, Durg, Madhya Pradesh. Observations made on the effect of various types of feed on survival and growth rate of Indian Major carp fry in nurseries are reported. Physico-chemical parameters and plankton populations in the three sets of nurseries are given. The experiments indicates that optimum survival rate of fry can be obtained by feeding tender spawn with animal protein feed. The economic viability of the experiment discussed shows that for a little increase in the expenditure on improved artificial food the survival and growth of fry can be enhanced.