17 resultados para 860[82].07[Alvarez]

em Aquatic Commons


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This cruise report is a summary of a field survey conducted in coastal-ocean waters off Florida from Anclote Key to West Palm Beach and from approximately 1 nautical mile (nm) offshore seaward to the shelf break (100 m). The survey was conducted May 15 - May 28, 2007 on NOAA Ship NANCY FOSTER Cruise NF-07-08-NCCOS. Multiple indicators of ecological condition were sampled synoptically at each of 50 stations throughout the region including 10 stations within the Florida Keys National Marine Sanctuary (FKNMS) using a random probabilistic sampling design. Samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants (metals, pesticides, PAHs, PCBs, PBDEs) in sediments and target demersal biota; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as depth, salinity, temperature, dissolved oxygen, pH, sediment grain size, and organic carbon content. The overall purpose of the survey was to collect data to assess the status of ecological condition in coastal-ocean waters of the region, based on these various indicators, and to provide this information as a baseline for determining how environmental conditions may be changing with time. The results will be of value in helping to broaden our understanding of the status of ecological resources and their controlling factors, including impacts of potential ecosystem stressors, in such strategic coastal areas. (PDF contains 34 pages

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From May 22 to June 4, 2006, NOAA scientists led a research cruise using the ROPOS Remotely Operated Vehicle (ROV) to conduct a series of dives at targeted sites in the Olympic Coast National Marine Sanctuary (OCNMS) with the goal of documenting deep coral and sponge communities. Dive sites were selected from areas for which OCNMS had side scan sonar data indicating the presence of hard or complex substrate. The team completed 11 dives in sanctuary waters ranging from six to 52 hours in length, at depths ranging from 100 to 650 meters. Transect surveys were completed at 15 pre-selected sites, with additional observations made at five other sites. The survey locations included sites both inside and outside the Essential Fish Habitat (EFH) Conservation Area, known as Olympic 2, established by the Pacific Fishery Management Council, enacted on June 12, 2006. Bottom trawling is prohibited in the Olympic 2 Conservation Area for nontribal fishermen. The Conservation Area covers 159.4 square nautical miles or about 15 percent of the sanctuary. Several species of corals and sponges were documented at 14 of the 15 sites surveyed, at sites both inside and outside the Conservation Area, including numerous gorgonians and the stony corals Lophelia pertusa and Desmophyllum dianthus, as well as small patches of the reef building sponge Farrea occa. The team also documented Lophelia sp. and Desmophyllum sp. coral rubble, dead gorgonians, lost fishing gear, and other anthropogenic debris, supporting concerns over potential risks of environmental disturbances to coral health. (PDF contains 60 pages.)

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The objective of this study was to describe the physical and ichthyological changes occurring seasonally and annually in the south San Francisco Bay, based on the results of 2,561 otter trawl and water samples obtained between February 1973 and June 1982. Temperature varied predictably among seasons in a pattern that varied little between years. Salinity also underwent predictable seasonal changes but the pattern varied substantially between years. The most abundant species of fish were northern anchovy (Engraulis mordax), English sole (Parophrys vetulus), and shiner surfperch (Cymatogaster aggregata). The majority of the common fish species were most abundant during wet years and least abundant in dry years. Numeric diversity was highest during the spring and early summer, with no detectable interannual trends. Species composition changed extensively between seasons and between years, particularly years with extremely high or extremely low freshwater inflows. All the common species exhibited clustered spatial distributions. Such spatial clustering could affect the interpretation of data from estuarine sampling programs. Gobies (Family Gobiidae) were more abundant during flood tides than during ebb tides. English sole were significantly more abundant in shallower areas. Shiner surfperch showed significant differences in abundance between sample areas.(PDF file contains 28 pages.)

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Comparative studies of the structure and regeneration of tissues in different vertebrates make it possible to get ideas from the evolution and regeneration potential of tissues. In this study are considered the reactive changes in the liver of larvae of the amphibian Rana temporaria to CC14 of different concentrations. Tadpoles of different sizes and different growth were placed once each day every day in a vessel with a determined solution of CC14 in water. The liver of tadpoles has a distinctive structure. It is distinguished by structure not only from the liver of higher vertebrates, but also from the liver of the adult frogs. The liver of the latter has an insignificant amount of fat and a whole series of other characters not typical of the liver of the tadpole. Placing the tadpoles in a solution of CCl4 with a concentration of 0.1% did not produce in the liver noticeable morphological changes. The author concludes that the absence of degenerative changes in the liver tadpoles, in spite of a high percentage of death of the experimental animals, tells of the well-known resistance of their liver to the influence of CC14.

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As explained in the title, this campaign aimed to assess the diurnal vertical variations in abundance of demersal species off the Côte d'Ivoire

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This publication gives the results of bottom trawlings made during the cruises CHALCI 84-01 and CHALCI 84-02 by the oceanographic research vessel "Andre NIZERY" sur le plateau continental ivoirien.

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This publication gives the results of the bottom trawlings made during the cruises Togo 1 and Togo 2 by the oceanographic research vessel "Andre Nizery" on the continental shelf of Togo during the estimation program of halieutic resources. The report includes: 1 - The report of the cruises Togo 1 and Togo 2; 2 - Some information on the presentation of the results; 3 - The trawl recording cards for the 2 cruises; 4 - The length frequency distributions of the measured samples.

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The report provides catch records for the Kapenta and inshore fisheries in the Zimbabwean waters of Lake Kariba for the year 1994. Kapenta usually constitute about 90% of the total catch from Lake Kariba; for statistical purposes catches are recorded for the 5 hydrological basins - Mlibizi, Binga, Sengwa, Bumi and Kariba. Whereas kapenta represent a unit stock which is harvested by both Zimbabwe and Zambia, the artisanal fishery exploits inshore species which generally occupy water less than 10m deep along the shoreline, considered to be 2 separate stocks. The main species in the inshore fishery are Oreochromis mortimeri, Sargochromis codringtonii, Tilapia rendalli, Labeo altivelis, Hydrocynus vittatus, Mormyrus longirostris, Clarias gariepinus and Synodontis zambezensis.

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The report looks at trials and results of sonic tracking devices. The report includes an appendix on a salmon tracking exercise using oxygen sensing ultrasonic transmitting tags which was carried out on the Ribble Estuary during the period 8th July 1982 to 19th July, 1982. The tags used were developed and manufactured by Aberdeen University and Zootelemetry Research Laboratory Ltd. of Aberdeen, working under contract from the Water Research Centre.

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This cruise report is a summary of a field survey conducted along a portion of the U.S. continental shelf in northwestern Gulf of Mexico (GOM), at navigable depths along the coastline seaward to the shelf break (~100m) from about 89°30' W to 95°28' W longitude, August 8 – 16, 2011 on NOAA Ship Nancy Foster Cruise NF-11-07-RACOW. Synoptic sampling of multiple ecological indicators was conducted at each of 34 stations throughout these waters using a random probabilistic sampling design. The original study design consisted of 50 stations extending from the Mississippi delta all the way to the U.S./Mexican border, but vessel failures precluded sampling at 16 stations within the western-most portion of the study area. At each station samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants in sediments and target demersal biota; sediment toxicity; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as salinity, temperature, dissolved oxygen, turbidity, pH, sediment grain size, and organic carbon content. Other indicators, from a human-dimension perspective, were also recorded, including presence of 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. While sample analysis is still ongoing, some preliminary results and observations are reported here. A final report will be completed once all data have been processed.