31 resultados para quantity surveying

em Aquatic Commons


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Vancouver Lake, located adjacent to the Columbia River and just north of the Vancouver-Portland metropolitan area, is a "dying" lake. Although all lakes die naturally in geologic time through the process of eutrophication,* Vancouver Lake is dying more rapidly due to man's activities and due to the resultant increased accumulation of sediment, chemicals, and wastes. Natural eutrophication takes thousands of years, whereas man-made modifications can cause the death of a lake in decades. Vancouver Lake does, however, have the potential of becoming a valuable water resource asset for the area, due particularly to its location near the Columbia River which can be used as a source of "flushing" water to improve the quality of Vancouver Lake. (Document pdf contains 59 pages) Community interest in Vancouver Lake has waxed and waned. Prior to World War II, there were relatively few plans for discussions about the Lake and its surrounding land area. A plan to drain the Lake for farming was prohibited by the city council and county commissioners. Interest increased in 1945 when the federal government considered developing the Lake as a berthing harbor for deactivated ships at which time a preliminary proposal was prepared by the City. The only surface water connection between Vancouver Lake and the Columbia River, except during floods, is Lake River. The Lake now serves as a receiving body of water for Lake River tidal flow and surface flow from creeks and nearby land areas. Seasonally, these flows are heavily laden with sediment, septic tank drainage, fertilizers and drainage from cattle yards. Construction and gravel pit operations increase the sediment loads entering the Lake from Burnt Bridge Creek and Salmon Creek (via Lake River by tidal action). The tidal flats at the north end of Vancouver Lake are evidence of this accumulation. Since 1945, the buildup of sediment and nutrients created by man's activities has accelerated the growth of the large water plants and algae which contribute to the degeneration of the Lake. Flooding from the Columbia River, as in 1968, has added to the deposition in Vancouver Lake. The combined effect of these human and natural activities has changed Vancouver Lake into a relatively useless body of shallow water supporting some wildlife, rough fish, and shallow draft boats. It is still pleasant to view from the hills to the east. Because precipitation and streamflow are the lowest during the summer and early fall, water quantity and quality conditions are at their worst when the potential of the Lake for water-based recreation is the highest. Increased pollution of the Lake has caused a larger segment of the community to become concerned. Land use and planning studies were undertaken on the Columbia River lowlands and a wide variety of ideas were proposed for improving the quality of the water-land environment in order to enhance the usefulness of the area. In 1966, the College of Engineering Research Division at Washington State University (WSU0 in Pullman, Washington, was contacted by the Port of Vancouver to determine possible alternatives for restoring Vancouver Lake. Various proposals were prepared between 1966 and 1969. During the summer and fall of 1967, a study was made by WSU on the existing water quality in the Lake. In 1969, the current studies were funded to establish a data base for considering a broad range of alternative solutions for improving the quantity and quality of Vancouver Lake. Until these studies were undertaken, practically no data on a continuous nature were available on Vancouver Lake, Lake River, or their tributaries. (Document pdf contains 59 pages)

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This report amplifies and refines some of the data already issued covering the water resources of Volusia County, which were published as Report of Investigations No. 21. The work in the report was accomplished as a cooperative program between the Department of Natural Resources, the U. S. Geological Survey and the Board of County Commissioners of Volusia County. Volusia County is almost totally dependent upon the water which falls upon the county and has a recharge area contained along the western portion and the central portions of the county. Excellent water is produced in the areal recharge and it is anticipated that this data will expand the existing knowledge of the water resources to permit the development of a great capacity for existing utilities and to offset and solve some of the problems now in the area. (PDF has 71 pages.)

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In most lakes, zooplankton production is constrained by food quantity, but frequently high C:P poses an additional constraint on zooplankton production by reducing the carbon transfer efficiency from phytoplankton to zooplankton. This review addresses how the flux of matter and energy in pelagic food webs is regulated by food quantity in terms of C and its stoichiometric quality in terms of C:P. Increased levels of light, CO2 and phosphorus could each increase seston mass and, hence, food quantity for zooplankton, but while light and CO2 each cause increased C:P (i.e. reduced food quality for herbivores), increased P may increase seston mass and its stoichiometric quality by reducing C:P. Development of food quality and food quantity in response to C- or P-enrichments will differ between 'batch-type' lakes (dominated by one major, seasonal input of water and nutrients) and 'continuous-culture' types of lakes with a more steady flow-rate of water and nutrients. The reciprocal role of food quantity and stoichiometric quality will depend strongly on facilitation via grazing and recycling by the grazers, and this effect will be most important in systems with low renewal rates. At high food abundance but low quality, there will be a 'quality starvation' in zooplankton. From a management point of view, stoichiometric theory offers a general tool-kit for understanding the integrated role of C and P in food webs and how food quantity and stoichiometric quality (i.e. C:P) regulate energy flow and trophic efficiency from base to top in food webs.From a management point of view, stoichiometric theory offers a general tool-kit for understanding the integrated role of C and P in food webs and how food quantity and stoichiometric quality (i.e. C:P) regulate energy flow and trophic efficiency from base to top in food webs.

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Any presence of bacterial human pathogen in shrimp products may be of public health concern. This note concludes that Salmonella do not appear to constitute a part of the microbial flora where shrimp culture is practiced in Thailand. Vibrio cholerae 01, the cause of cholera are rarely recovered from the environment with no isolates containing genes encoding cholera toxin. Further studies are needed to describe the prevalence of bacterial human pathogens in shrimp culture, especially determination of possible postharvest cross-contamnation with these pathogens

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Studies on the nutrient composition of smoked-dried Clarias gariepinus were carried out, to assess the effects of pest infestation on the dried catfish from two different market (Abakpa and Kpirikpiri market) area in Abakaliki Metropolis, Ebonyi State, Nigeria. Fish samples from the two markets where kept for pest to infest it and it were taken to Biochemistry Laboratory of Food Science and Technology in Ebonyi State University to assess the damage of pest on dried catfish using standard methods. There was a significant different among the mean weight of fish from the two markets (Abakpa and kpirikpiri; 19.13kg and 18.98kg respectively) compared with the mean weight of the control 20.09kg. There was a variation in the proximate composition of the fishes from the two markets compared with the control, the decreases of the proximate composition are: crude protein from 60.07% to 40.27%; fat from 8.35% to 5.90%; moisture content from 11.67% to 10.67; fiber from 12.93 to 11.93; ash from 4.02% to 3.54% and carbohydrate 12.67% to 5.89%. The longer the storage periods of the infested smoked fish the more the tissue was degraded. Proper handling and storage of dried catfish are required to prolong the shelf life and nutrient content of dried catfish.

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In recent years, difficulties encountered in obtaining ground-water supplies with acceptable chemical characteristics in the Myakka River basin area led to the implementation of a test drilling program. Under this program, well drilling and data collection were executed in such a manner that all water-producing zones of the local aquifers, together with the quality and quantity of the water available, were effectively identified. A step-drilling method was utilized which allowed the collection of formation cuttings, water samples, and water-level data, from isolated zones in the well as drilling proceeded. The step drilling procedure is described. The driller's logs, geophysical logs, and chemical quality of water tables are presented.(Document has 66 pages.)

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The purpose of the investigation is to make a detailed study of the geology and ground water in the Ruskin area, especially as related to the problem of salt-water encroachment. The major objectives of the program includes: (1) An inventory of wells to determine their number and distribution, their depths and diameters, and other pertinent information. (2) A study of artesian pressures. (3) Analyses of water from selected wells to determine the location and extent of any areas in which the artesian water is salty. (4) A study of the surface and subsurface geology as related to the occurrence and movement of ground water. (5) An estimate of the quantity of ground water withdrawn. (PDF contains 24 pages.)

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The Oakland Park area obtains its water from the Biscayne aquifer, S composed of very permeable and porous, sandy limestones. The per- 3 meability of the aquifer increases with depth, and wells in the area <\ generally obtain water at depths ranging from 60 to 80 feet, or between S 100 and 200 feet, depending on the quantity of water desired. The data presented in this paper can be used for further development of water and wise management of resources in the area. Large quantities S of ground water are still available at Oakland Park, if salt-water encroachment can be controlled. The data in this study provide the necessary information to begin an effective water management program. (PDF has 49 pages)

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Habitat mapping and characterization has been defined as a high-priority management issue for the Olympic Coast National Marine Sanctuary (OCNMS), especially for poorly known deep-sea habitats that may be sensitive to anthropogenic disturbance. As a result, a team of scientists from OCNMS, National Centers for Coastal Ocean Science (NCCOS), and other partnering institutions initiated a series of surveys to assess the distribution of deep-sea coral/sponge assemblages within the sanctuary and to look for evidence of potential anthropogenic impacts in these critical habitats. Initial results indicated that remotely delineating areas of hard bottom substrate through acoustic sensing could be a useful tool to increase the efficiency and success of subsequent ROV-based surveys of the associated deep-sea fauna. Accordingly, side scan sonar surveys were conducted in May 2004, June 2005, and April 2006 aboard the NOAA Ship McArthur II to: (1) obtain additional imagery of the seafloor for broader habitat-mapping coverage of sanctuary waters, and (2) help delineate suitable deep-sea coral/sponge habitat, in areas of both high and low commercial-fishing activities, to serve as sites for surveying-in more detail using an ROV on subsequent cruises. Several regions of the sea floor throughout the OCNMS were surveyed and mosaicked at 1-meter pixel resolution. Imagery from the side scan sonar mapping efforts was integrated with other complementary data from a towed camera sled, ROVs, sedimentary samples, and bathymetry records to describe geological and biological (where possible) aspects of habitat. Using a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999), we created a preliminary map of various habitat polygon features for use in a geographical information system (GIS). This report provides a description of the mapping and groundtruthing efforts as well as results of the image classification procedure for each of the areas surveyed. (PDF contains 60 pages.)

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With elevating interest to establish conservation efforts for groundfish stocks and continued scrutiny over the value of marine protected areas along the west coast, the importance of enhancing our knowledge of seabed characteristics through mapping activities is becoming increasingly more important, especially in a timely manner. Shortly after the inception of the Seabed Mapping Initiative instituted with the US Geological Survey (USGS), the National Marine Sanctuary Program (NMSP) assembled a panel of habitat mapping experts. They determined that the status of existing data sets and future data acquisition needs varied widely among the individual sanctuaries and that more detailed site assessments were needed to better prioritize mapping efforts and outline an overall joint strategy. To assist with that specific effort and provide pertinent information for the Olympic Coast National Marine Sanctuary’s (OCNMS) Management Plan Review, this report summarizes the mapping efforts that have taken place at the site to date; calculates a timeframe for completion of baseline mapping efforts when operating under current data acquisition limitations; describes an optimized survey strategy to dramatically reduce the required time to complete baseline surveying; and provides estimates for the needed vessel sea-days (DAS) to accomplish baseline survey completion within a 2, 5 and 10 year timeframe. (PDF contains 38 pages.)

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Mytilus californianus communities (mussel beds) were examined from six geographic localities in Southern California. These included two mainland sites, Coal Oil Point and San Diego; and four island sites, San Miguel, Santa Cruz, San Nicholas, and Santa Barbara Islands. Optimal sample sizes were determined for each locality. In general, a sample, size of 1500 cm2 (five cores) was optimal for the "typical" mussel bed. However, structurally unique mussel beds required individual consideration. Community biomass, diversity, species richness, and species evenness were calculated quarterly for the island localities and biannually for mainland locations. The molluscs, primarily the mussels, accounted for 90% of the total biomass while all other groups combined accounted for 10% or less of the total biomass. The mussel communities from all localities contributed to the master species list which conservatively contained 346 species. The most diverse localities were Coal Oil Point and Santa Cruz Island with an average number of 73 and 74 species/O.lS m respectively. No overall seasonal patterns existed in community composition. The community similarity analyses showed the mainland localities biotically dissimilar from the islands and both groups were characterized by distinct faunal assemblages. In addition, San Miguel Island biota were unique among the island sites. The most important mussel bed structural attributes provided habitats for the associated community and included sediment and coarse fraction features. Food-related resources provided by the mussel bed were secondarily important. Community diversity generally increased with the quantity of habitat and food resources. (PDF contains 138 pages)

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The communities associated with Mytilus californianus (mussel) beds from 20 geographic sites in southern California were examined. The study areas included six mainland sites - Government Point, Goleta Point, Ventura, Corona del Mar, Carlsbad, and San Diego,and two sites on opposite sides of seven offshore islands - San Miguel Island, Santa Rosa Island, Santa Cruz Island, Anacapa Island, San Nicholas Island, Santa Cruz Island and San Clemente Island. : The mussel communities from all areas contributed to the master species list which now encompasses conservatively, 610 species of animals and 141 species of algae. The most diverse collection came from Cat Rock, Anacapa Island where the mussel beds supported 174 species of invertebrates. The lowest diversity was recorded for mussel beds from Ben Weston, Santa Catalina Island which contained 46 species. In general, the island mussel beds supported a greater diversity of both animals and plants. Mussel community samples were collected from upper and lower intertidal areas occupied by the mussel beds within a locality. Community differences in both composition and abundance were associated with these collections. Overall. community similarity analysis revealed five major patterns which corresponded to characteristic species assemblages occupying the mussel beds from the various geographic areas. The patterns included: (1) clusters of localities which display a north-south geographic pattern with respect to the similarity of their respective mussel communities, (2) a separation of selected island and mainland communities because of dissimilarities in their species composition, (3) differences between mussel communities. on opposite sides of the offshore islands, (4) clusters of species whose highest abundances characterize selected localities, (5) species groups ubiquitous to all mussel beds examined. The results of the community analysis further suggest that predictions can be made delineating the probable mussel community inhabitants of areas not sampled. The species distribution patterns observed appear to correspond in part to the influence of currents and water masses which bear planktonic larvae and impinge on selected localities. The most important mussel bed features associated with community differences were quantitative and qualitative differences in the potential microhabitats. Those features associate~ with greater species diversity include the pore base of coarse fraction shell and rock debris, skewness and kurtosis of the sediment grain-size distributions and mussel bed thickness. Those features associated with lower species diversity included the quantity of tar. and rock and shell debris trapped within the mussel bed. (PDF contains 51 pages)

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From the mid-1950's to the mid-1960's a series of quantitative surveys of the macrobenthic invertebrate fauna were conducted in the offshore New England region (Maine to Long Island, New York). The surveys were designed to 1) obtain measures of macrobenthic standing crop expressed in terms of density and biomass; 2) determine the taxonomic composition of the fauna (ca. 567 species); 3) map the general features of macrobenthic distribution; and 4) evaluate the fauna's relationships to water depth, bottom type, temperature range, and sediment organic carbon content. A total of 1,076 samples, ranging from 3 to 3,974 m in depth, were obtained and analyzed. The aggregate macrobenthic fauna consists of 44 major taxonomic groups (phyla, classes, orders). A striking fact is that only five of those groups (belonging to four phyla) account for over 80% of both total biomass and number of individuals of the macrobenthos. The five dominant groups are Bivalvia, Annelida, Amphipoda, Echninoidea, and Holothuroidea. Other salient features pertaining to the macrobenthos of the region are the following: substantial differences in quantity exist among different geographic subareas within the region, but with a general trend that both density and biomass increase from northeast to southwest; both density and biomass decrease with increasing depth; the composition of the bottom sediments significantly influences both the kind and quantity of macrobenthic invertebrates, the largest quantities of both measures of abundance occurring in the coarser grained sediments and diminishing with decreasing particle size; areas with marked seasonal changes in water temperature support an abundant and diverse fauna, whereas a uniform temperature regime is associated with a sparse, less diverse fauna; and no detectable trends are evident in the quantitative composition of the macrobenthos in relation to sediment organic carbon content. (PDF file contains 246 pages.)

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ENGLISH: Morphometric studies by Godsil (1948), Godsil and Greenhood (1951), Royce (1953) and Schaefer (1952, 1955) have indicated that the yellowfin tuna of the Eastern Pacific are distinct from those of the Central Pacific. Tagging of yellowfin tuna by the California Department of Fish and Game, and by the Inter-American Tropical Tuna Commission in the Eastern Pacific, and by the Pacific Oceanic Fishery Investigations in the Central Pacific, have not yet revealed any migrations between these areas. Shimada and Schaefer (1956) have compared changes in population abundance and fishing intensity, considering the population in the Eastern Pacific as a separate entity. They conclude " ... the amount of fishing has had a real effect upon the stock of Eastern Pacific yellowfin tuna, taken in the aggregate, over the period studied. The evidence suggests also that for this species the intensity of fishing in some recent years has reached and might have even exceeded the level corresponding to the maximum equilibrium yield." Tagging experiments by the California Department of Fish and Game and by the Inter-American Tropical Tuna Commission have yielded returns in the order of one to five percent (Roedel 1954, and unpublished data of both agencies), a level much lower than that at which fishing intensity would be expected to noticeably affect the population size. These results are probably a reflection of the inadequacies of the present tagging methods, but they could lend doubt to the conclusions of Shimada and Schaefer. It is desirable, therefore, to examine other, independent, evidence as to the effects of fishing on the population. At the high levels of fishing intensity suggested by Shimada and Schaefer, in addition to changes in quantity, measurable changes would be expected to have occurred in the quality of the yellowfin tuna stocks, because the average age and size of the fish would have been reduced by the high mortality rates accompanying high fishing intensities. A continuing regular program of sampling catches and determining their length composition, to assess changes in the size composition of the stocks, was initiated by the Commission in 1954 but direct measurements are not available for the earlier, more dynamic period of growth of the fishery. Consequently, other, more general indications of possible changes in the size composition were sought. SPANISH: Los estudios morfométricos efectudos por Godsil (1948), Godsil y Greenhood (1951), Royce (1953) y Schaefer (1952, 1955), han demostrado que el atún aleta amarilla del Pacífico Oriental es distinto del que habita el PacÍfico Central. Los experimentos del Departamento de Pesca y Caza de California y de la Comisión Interamericana del Atún Tropical en el Pacífico Oriental, así como los de las Investigaciones Pesqueras del Océano Pacífico en el Pacífico Central,consistentes en la marcación de atunes aleta amarilla, aún no han puesto de manifiesto movimientos migratorios entre dichas áreas. Shimada y Schaefer (1956) han hecho estudios comparativos sobre la abundancia de la población y la intensidad de la pesca, considerando a la población del Pacífico Oriental como una entidad separada. Su conclusión es que " ... la intensidad de la pesca ha tenido un definido efecto sobre la población del atún aleta amarilla del Pacífico Oriental, tomada en conjunto, a lo largo del período estudiado. La evidencia de que se dispone sugiere así mismo que, por lo que hace a esta especie, la intensidad de la pesca en los últimos años ha alcanzado y quizás aún sobrepasado el nivel correspondiente a la máxima pesca de equilibrio". Los experimentos de mar•cación del Departamento de Pesca y Caza de California y de la Comisión Interamericana del Atún Tropical han producido recuperaciones ,entre el uno y el cinco por ciento (Roedel 1954 y datos inéditos de ambos organismos), lo que constituye un nivel mucho más bajo de aquél en que la intensidad de la pesca podría considerarse que afectaría notablemente el tamaño de la población. Estos resultados reflejan probablemente lo inadecuados que son aún los métodos de marcación, pero ellos podrían, quizá, poner en tela de juicio las conclusiones de Shimada y Schaefer. Por lo tanto,es deseable examinar otras fuentes de evidencia independientes, relacionadas con el efecto que la pesca tiene sobre la población. En efecto, si los altos índices de pesca sugeridos por Shimada y Schaefer son correctos, es de esperar que, además de los cambios en la magnitud de la población, se hayan producido otros, concomitantes y sensibles, en la calidad de los stocks de atún aleta amarilla, puesto que tanto el promedio de edad como el de tamaño de los individuos habrían disminuído debido a las elevadas tasas de mortalidad inherentes a las altas intensidades de pesca. En 1954 la Comisión inició un programa ininterrumpido para tomar muestras y determinar en ellas las frecuencias de tallas y evaluar de este modo los cambios correlativos que tuvieran lugar en los stocks pero, infortunadamente, este sistema de evaluación directa no fué practicado en el período anterior, que fué precisamente el de rápida expansión de la pesquería. En tal virtud, hubo de ser necesario buscar indicios más generales referentes a los cambios posibles en la composición de tamaños. (PDF contains 20 pages.)

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Based on the EU Regulation 1543/2000 for the improvement of quantity and quality of fishery data the Federal Ministry for Consumer Protection, Food and Agriculture has initiated a national data collection programme, executed by three institutions, Federal Research Centre for Fisheries (BFAFi), Federal Agency for Ariculture and Food and the Federal Research Centre Agriculture, co-ordinated by BFAFi. In 2004 samples have been taken from 943 hauls during 29 commercial fishing trips; 357 000 fish have been measured. From 2002 to 2004 the number of length and weight and measurements, and age determinations could increased by 32, 65 and 156 % resp. Pilot inquiries have been carried out to prepare also the collection of economical date of fishing vessels and of fish processing plants from 2006.