120 resultados para Pacific Coast (North America)
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Trace metal analysis of 23 species of common Pacific Coast marine foods revealed high cadmium values for Bent-nosed clams (Macoma nasuta), Bay mussels (Mytilus edulis), Bay oysters (Osrtrea lurida), Pacific oysters (Crassostrea gigas), and Littleneck clams (Protothaca staminea). Metals were found to concentrate in the gills, heart, and visceral mass of all 10 species of bivalve mollusks examined. Swordfish (Xiphias gladius) and Salmon (Oncorhynchus tshawytscha) demonstrated the highest cadmium values for fish flesh.
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This present study investigates the influence of western Pacific tropical cyclone activity as possible centers of anomalous tropical heating on the large-scale circulation over the Pacific region. The characterization of tropical cyclone activity via an index based on anomalous 700 mb zonal wind is described first. Patterns of anomalous large-scale extratropical circulation anomalies based on composites of similar periods of tropical cyclone activity are then presented, followed by general conclusions.
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EXTRACT (SEE PDF FOR FULL ABSTRACT): As part of a study of climatic influences on landslide initiation, a statistical analysis of long-term (>40 years) records of daily rainfall from 24 Pacific coastal stations, from San Diego to Cape Flattery, disclosed an unexpected result - the square root of the daily rainfall closely approximates a normal distribution function. ... This paper illustrates the use of the square-root-normal distribution to analyze variations in precipitation along the mainland United States Pacific Coast with examples of orographic enhancement, rain shadows, and increase in precipitation frequency with geographic latitude.
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EXECUTIVE SUMMARY INTRODUCTION OVERVIEW OF INTERNATIONAL EBM HISTORY References CANADA Overview Activities to date Integrated Management implementation in Canada Objectives, indicators and reference points Assessment approaches Research directions for the future Management directions for the future References JAPAN Overview Conservation and sustainable use of marine living resources Harvest control by TAC system Stock Recovery Plan and effort regulation system Stock enhancement by hatchery-produced juvenile release Conservation and sustainable develop-ment on coastal waters The implementation of ecosystem-based management PEOPLE’S REPUBLIC OF CHINA Overview Current actions Output control Input control Summer fishing ban Enhance ecosystem health REPUBLIC OF KOREA Initiatives and actions of ecosystem-based management in Korea Current ecosystem-based management initiatives in Korea Precautionary TAC-based fishery management Closed fishing season/areas Fish size- and sex-controls Fishing gear design restrictions Marine protected areas (MPA) RUSSIA Existing and anticipated ecosystem-based management initiatives Issues related to the implementation of ecosystem-based management UNITED STATES OF AMERICA Definitions and approaches to ecosystem-based fishery management in the United States Present U.S. legislative mandates relating to ecosystem-based fishery management Target species Bycatch species Threatened or endangered species Habitats Food webs Ecosystems Integration of legislative mandates into an ecosystem approach Scientific issues in implementing ecosystem-based approaches References DISCUSSION AND RECOMMENDATIONS APPENDICES Appendix 10.1 Study group membership and participants Appendix 10.2 Terminology definitions Appendix 10.3 Present state of implementing ecosystem-based fishery management in Alaska: Alaska groundfish fisheries Appendix 10.4 Present state of implementing ecosystem-based fishery management off the West Coast of the United States: Pacific Coast groundfish fisheries Appendix 10.5 Descriptions of multi-species and ecosystem models developed or under development in the U.S. North Pacific region that might be used to predict effects of fishing on ecosystems Appendix 10.6 A potential standard reporting format (developed by Australia, and currently being used by the U.S.A in their contribution to this report) (83 page document)
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The eastern Steller sea lion (Eumetopias jubatus) population comprises animals that breed along the west coast of North America between California and southeastern Alaska. There are currently 13 major rookeries (>50 pups): five in southeastern Alaska, three in British Columbia, two in Oregon, and three in California. Overall abundance has increased at an average annual rate of 3.1% since the 1970s. These increases can largely be attributed to population recovery from predator-control kills and commercial harvests, and abundance is now probably as high as it has been in the last century. The number of rookeries has remained fairly constant (n=11 to 13) over the past 80 years, but there has been a northward shift in distribution of both rookeries and numbers of animals. Based on the number of pups counted in a population-wide survey in 2002, total pup production was estimated to be about 11,000 (82% in southeastern Alaska and British Columbia), representing a total population size as approximately 46,000−58,000 animal
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Numerous integrated time series have been assembled that suggest global temperature has been increasing steadily over the last century. ... However, superimposed on the long-term warming trends of these series are decadal-scale fluctuations, periods of slightly increasing and even decreasing temperature followed by rapid increases in temperature. ... In this pilot study, data for 1931-1990 from eight [western North America] coastal stations are examined to test the utility of a state-space statistical model (developed by Dr. Roy Mendelssohn, PFEG) in separating and describing seasonal patterns and long-term trends.
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The Pacific sardine (Sardinops sagax) is distributed along the west coast of North America from Baja California to British Columbia. This article presents estimates of biomass, spawning biomass, and related biological parameters based on four trawl-ichthyoplankton surveys conducted during July 2003 –March 2005 off Oregon and Washington. The trawl-based biomass estimates, serving as relative abundance, were 198,600 t (coefficient of variation [CV] = 0.51) in July 2003, 20,100 t (0.8) in March 2004, 77,900 t (0.34) in July 2004, and 30,100 t (0.72) in March 2005 over an area close to 200,000 km2. The biomass estimates, high in July and low in March, are a strong indication of migration in and out of this area. Sardine spawn in July off the Pacific Northwest (PNW) coast and none of the sampled fish had spawned in March. The estimated spawning biomass for July 2003 and July 2004 was 39,184 t (0.57) and 84,120 t (0.93), respectively. The average active female sardine in the PNW spawned every 20–40 days compared to every 6–8 days off California. The spawning habitat was located in the southeastern area off the PNW coast, a shift from the northwest area off the PNW coast in the 1990s. Egg production in off the PNW for 2003–04 was lower than that off California and that in the 1990s. Because the biomass of Pacific sardine off the PNW appears to be supported heavily by migratory fish from California, the sustainability of the local PNW population relies on the stability of the population off California, and on local oceanographic conditions for local residence.
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EXTRACT (SEE PDF FOR FULL ABSTRACT): Examining secular changes in relative sea level along the U.S. west coast, we have identified strong tectonic signals. Tectonism exists not only on a coherent plate-wide scale (assuming a rigid plate approximation), but also on a sub-plate scale. In fact, differential tectonism between exotic or suspect geological terrain explains much of the spatial patterns of west coast tide-gauge data. Peltier's isostatic model appears not to explain the spatial pattern, implying glacio-isostatic adjustment is not the dominant contribution to the low-frequency signals. Eustatic effects cannot be identified unambiguously. These studies suggest several major questions/observations with regard to relative sea-level studies ...
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EXTRACT (SEE PDF FOR FULL ABSTRACT): The annual cycle and non-seasonal variability of streamflow over a network of stations in western North America and Hawaii is studied in terms of atmospheric forcing elements. The phase lag between the annual cycle of streamflow and precipitation varies considerably over this network, as does the persistence of monthly streamflow anomalies. This lag effect appears to be largely a function of the relative amount of snow laid down in a particular basin. In addition to the rather strong annual cycle that exists in mean streamflow and its variance at most of the stations, there is also a distinct annual cycle in the autocorrelation of streamflow anomalies that is related to the interplay between the temperature and precipitation annual cycles; of particular importance is the existence of stored water in the form of a snow pack.
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About 72 species of Sebastes (Family Scorpaenidae) are found along the eastern Pacific coast of North America, some of which are heavily exploited by both commercial and sport fisheries. Because of the large number of species, the identification of early life stages has progressed slowly. The objectives of this study were 1) to rear the larvae of four species of rockfish (Sebastes mystinus, S. carnatus, S. atrovirens, and S. rastrelliger); and 2) to describe the larvae using morphometric measurements, pigmentation patterns, and head spination. Pigmentation was the most useful feature for identification purposes. Two general patterns were found: 1) a short row of ventral midline melanophores on the tail, and none or very little postero-dorsal pigmentation (S. mystinus); and 2) complete ventral midline pigmentation on the tail, and anterior and postero-dorsal melanophores (S. carnatus, S. atrovirens, and S. rastrelliger). With the exception of very early stages of S. carnatus and S. atrovirens, these species can be readily identified. Morphometric proportions and head spination did not show major differences among species. Because of the great similarities found among species in this genus, descriptions from field studies are uncertain to some extent. Laboratory rearings, although difficult, can at least provide early larvae from known species which allow precise identification as well as an estimation ofvariability of characters (e.g., pigmentation) within and between broods.(PDF file contains 22 pages.)