WorldWideScience

Sample records for eastern pacific shared

  1. Eastern Pacific Ocean Conference

    Science.gov (United States)

    The promotion of interaction among investigators of all oceanographic disciplines studying the eastern Pacific Ocean was the goal of the 1990 Eastern Pacific Ocean Conference (EPOC), held October 17-19 on the snow-covered slopes of Mt. Hood, Oreg. Thirty oceanographers representing all disciplines attended.Dick Barber, Duke University Marine Lab, Beaufort, N.C., chaired a session on the eastern equatorial Pacific Ocean, emphasizing issues related to biological activity. Steve Ramp of the Naval Postgraduate School in Montery, Calif., chaired a session on recent results from northern and central California experiments. On October 19, following an early morning earthquake, a business meeting and discussions regarding a collaboration in future experiments were held.

  2. Eastern Pacific Ocean Purse-seine Fishery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vessel logbook and landings data sets from U.S.A.-flagged purse-seine vessels fishing in the Eastern Pacific Ocean (EPO). These purse seiners...

  3. Requiem for an eastern Pacific seagrass bed.

    Science.gov (United States)

    Cortés, J

    2001-12-01

    Few papers concerning seagrasses of the eastern Pacific have been published. This paper presents the first ecological data on the seagrass, Ruppia maritima, from a non-lagoonal setting in the eastern Pacific. A 5000 m2 patch formed by R. maritima, at Playa Iguanita, Bahía Culebra, Pacific coast of Costa Rica was studied. Plant density and leaf length of R. maritima were determined along two transects on different dates. Above and below ground biomass were calculated along one transect. Plant density ranged from 1590 to 8630 individuals m(-2) along the two transects, with means of 5990 +/- 1636 and 6100 +/- 1876 plants m(-2) for transect 1 and 2, respectively. Longest leaf length per plant varied between 0.5 and 23.0 cm. Leaf biomass (LB) ranged from 10 to 97 gm(-2), and root-rhizome biomass (RB) from 31 to 411 gm(-2), resulting in RB:LB ratios of 3.07 to 15.27. Total biomass at Bahía Culebra was lower than at tropical lagoons on the Pacific coast of Mexico, but higher than in the Gulf of Mexico. The below ground: above ground biomass ratio was much higher at Bahía Culebra than at other sites on the Pacific coast of Mexico and the Gulf of Mexico. Another seagrass present at Bahía Culebra was Halophila baillonii, with low densities on the deepest section of the patch. At least 44 invertebrate species associated with the seagrass bed have also been identified. The patch at Playa Iguanita and other sites within Bahía Culebra, as well as their associated organisms, disappeared after a severe storm in June 1996. No seagrasses have been found in the area or in any other location on the Pacific coast of Costa Rica since then.

  4. Eastern Equatorial Pacific Sea Level Pressure (1949-present)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is one of the CPC?s Monthly Atmospheric and SST Indices. It contains standardized sea level pressure anomalies over the equatorial eastern Pacific region...

  5. Status of marine mammals in the eastern North Pacific Ocean

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the status or marine mammals in the eastern north Pacific Ocean. Species covered are: sea otter, northern, Guadalupe fur seals, stellar,...

  6. Genetic isolation between the Western and Eastern Pacific populations of pronghorn spiny lobster Panulirus penicillatus.

    Science.gov (United States)

    Chow, Seinen; Jeffs, Andrew; Miyake, Yoichi; Konishi, Kooichi; Okazaki, Makoto; Suzuki, Nobuaki; Abdullah, Muhamad F; Imai, Hideyuki; Wakabayasi, Toshie; Sakai, Mitsuo

    2011-01-01

    The pronghorn spiny lobster, Panulirus penicillatus, is a circumtropical species which has the widest global distribution among all the species of spiny lobster, ranging throughout the entire Indo-Pacific region. Partial nucleotide sequences of mitochondrial DNA COI (1,142-1,207 bp) and 16S rDNA (535-546 bp) regions were determined for adult and phyllosoma larval samples collected from the Eastern Pacific (EP)(Galápagos Islands and its adjacent water), Central Pacific (CP)(Hawaii and Tuamotu) and the Western Pacific (WP)(Japan, Indonesia, Fiji, New Caledonia and Australia). Phylogenetic analyses revealed two distinct large clades corresponding to the geographic origin of samples (EP and CP+WP). No haplotype was shared between the two regional samples, and average nucleotide sequence divergence (Kimura's two parameter distance) between EP and CP+WP samples was 3.8±0.5% for COI and 1.0±0.4% for 16S rDNA, both of which were much larger than those within samples. The present results indicate that the Pacific population of the pronghorn spiny lobster is subdivided into two distinct populations (Eastern Pacific and Central to Western Pacific), with no gene flow between them. Although the pronghorn spiny lobster have long-lived teleplanic larvae, the vast expanse of Pacific Ocean with no islands and no shallow substrate which is known as the East Pacific Barrier appears to have isolated these two populations for a long time (c.a. 1MY).

  7. Hydrography of the eastern tropical Pacific: A review

    Science.gov (United States)

    Fiedler, Paul C.; Talley, Lynne D.

    2006-05-01

    Eastern tropical Pacific Ocean waters lie at the eastern end of a basin-wide equatorial current system, between two large subtropical gyres and at the terminus of two eastern boundary currents. Descriptions and interpretations of surface, pycnocline, intermediate and deep waters in the region are reviewed. Spatial and temporal patterns are discussed using (1) maps of surface temperature, salinity, and nutrients (phosphate, silicate, nitrate and nitrite), and thermocline and mixed layer parameters, and (2) meridional and zonal sections of temperature, salinity, potential density, oxygen, and nutrients. These patterns were derived from World Ocean Database observations by an ocean interpolation algorithm: loess-weighted observations were projected onto quadratic functions of spatial coordinates while simultaneously fitting annual and semiannual harmonics and the Southern Oscillation Index to account for interannual variability. Contrasts between the equatorial cold tongue and the eastern Pacific warm pool are evident in all the hydrographic parameters. Annual cycles and ENSO (El Niño-Southern Oscillation) variability are of similar amplitude in the eastern tropical Pacific, however, there are important regional differences in relative variability at these time scales. Unique characteristics of the eastern tropical Pacific are discussed: the strong and shallow pycnocline, the pronounced oxygen minimum layer, and the Costa Rica Dome. This paper is part of a comprehensive review of the oceanography of the eastern tropical Pacific.

  8. Authigenic Uranium in Eastern Equatorial Pacific Sediments

    Science.gov (United States)

    Marcantonio, F.; Lyle, M. W.; Loveley, M. R.; Ibrahim, R.

    2014-12-01

    Authigenic U concentrations have been used as an indicator of redox state in marine sediments. Soluble U(VI) in porewaters is reduced to insoluble U(IV) under suboxic conditions setting up a diffusion gradient through which U in bottom waters is supplied to reducing sediments. Researchers have used sedimentary redox enrichment of U as a tool to identify past redox changes, which may be caused by changes in organic carbon rain rates and/or bottom water oxygen levels. Differentiating between these two explanations is important, as the former is tied to the use of authigenic U as a paleoproductivity proxy. We examined sediments from 4 sediment cores retrieved from two different localities in the Panama Basin in the eastern equatorial Pacific. Two cores were retrieved from the northern Panama basin at the Cocos Ridge, (4JC at 5° 44.7'N 85° 45.5' W, 1730 m depth; 8JC at 6° 14.0'N 86° 2.6' W, 1993 m depth), and two were retrieved from the south at the Carnegie Ridge, (11JC at 0° 41.6'S 85° 20.0' W, 2452 m depth; 17JC at 0° 10.8'S 85° 52.0' W, 2846 m depth). Using 230Th systematics and seismic profiling at each of the sites, we've identified significant sediment winnowing (4JC and 11JC) and focusing (8JC and 17JC). At all sites, we believe that changes in age-model-derived sand (i.e., >63µm) mass accumulation rates (MAR) best represent changes in rain rates. Glacial rain rates are higher than those in the Holocene by a factor of 2-3 at both sites. Peak Mn levels (>1%), the brown-to-green color transition (which likely represents the oxic/post-oxic boundary), and peak U concentrations all appear in the same order with increasing depth down core. At the Carnegie sites, where MARs are greater than those at the Cocos sites, increases in authigenic U (up to 4 ppm) occur during the mid- to late Holocene at depths of 10-15 cm. At the Cocos sites, increases in authigenic U (up to 12 ppm) occur lower in the sediment column (25-30 cm) during the late glacial. The decrease

  9. Primary production in the eastern tropical Pacific: A review

    Science.gov (United States)

    Pennington, J. Timothy; Mahoney, Kevin L.; Kuwahara, Victor S.; Kolber, Dorota D.; Calienes, Ruth; Chavez, Francisco P.

    2006-05-01

    The eastern tropical Pacific includes 28 million km 2 of ocean between 23.5°N and S and Central/South America and 140°W, and contains the eastern and equatorial branches of the north and South Pacific subtropical gyres plus two equatorial and two coastal countercurrents. Spatial patterns of primary production are in general determined by supply of macronutrients (nitrate, phosphate) from below the thermocline. Where the thermocline is shallow and intersects the lighted euphotic zone, biological production is enhanced. In the eastern tropical Pacific thermocline depth is controlled by three interrelated processes: a basin-scale east/west thermocline tilt, a basin-scale thermocline shoaling at the gyre margins, and local wind-driven upwelling. These processes regulate supply of nutrient-rich subsurface waters to the euphotic zone, and on their basis we have divided the eastern tropical Pacific into seven main regions. Primary production and its physical and chemical controls are described for each. Enhanced rates of macronutrient supply maintains levels of primary production in the eastern tropical Pacific above those of the oligotrophic subtropical gyres to the north and south. On the other hand lack of the micronutrient iron limits phytoplankton growth (and nitrogen fixation) over large portions of the open-ocean eastern tropical Pacific, depressing rates of primary production and resulting in the so-called high nitrate-low chlorophyll condition. Very high rates of primary production can occur in those coastal areas where both macronutrients and iron are supplied in abundance to surface waters. In these eutrophic coastal areas large phytoplankton cells dominate; conversely, in the open-ocean small cells are dominant. In a ‘shadow zone’ between the subtropical gyres with limited subsurface ventilation, enough production sinks and decays to produce anoxic and denitrified waters which spread beneath very large parts of the eastern tropical Pacific. Seasonal

  10. Genetic isolation between the Western and Eastern Pacific populations of pronghorn spiny lobster Panulirus penicillatus.

    Directory of Open Access Journals (Sweden)

    Seinen Chow

    Full Text Available The pronghorn spiny lobster, Panulirus penicillatus, is a circumtropical species which has the widest global distribution among all the species of spiny lobster, ranging throughout the entire Indo-Pacific region. Partial nucleotide sequences of mitochondrial DNA COI (1,142-1,207 bp and 16S rDNA (535-546 bp regions were determined for adult and phyllosoma larval samples collected from the Eastern Pacific (EP(Galápagos Islands and its adjacent water, Central Pacific (CP(Hawaii and Tuamotu and the Western Pacific (WP(Japan, Indonesia, Fiji, New Caledonia and Australia. Phylogenetic analyses revealed two distinct large clades corresponding to the geographic origin of samples (EP and CP+WP. No haplotype was shared between the two regional samples, and average nucleotide sequence divergence (Kimura's two parameter distance between EP and CP+WP samples was 3.8±0.5% for COI and 1.0±0.4% for 16S rDNA, both of which were much larger than those within samples. The present results indicate that the Pacific population of the pronghorn spiny lobster is subdivided into two distinct populations (Eastern Pacific and Central to Western Pacific, with no gene flow between them. Although the pronghorn spiny lobster have long-lived teleplanic larvae, the vast expanse of Pacific Ocean with no islands and no shallow substrate which is known as the East Pacific Barrier appears to have isolated these two populations for a long time (c.a. 1MY.

  11. Share Information across the Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    Yang Wei

    2007-01-01

    @@ Ms.Mayo Tsirigotis Oge,Director of Office of Transportation and Air Quality,Environmental Protection Agency of United States"flew across the Pacifie Ocean to share the experiences and exchange information with China".That was what she said when interviewed by China's Foreign Trade.Yes,to ioin the International Forum on Chinese Automotive Industry Development was an important stagc to make communications across the cotmtries and continents.

  12. 75 FR 68756 - Eastern North Pacific Gray Whale; Notice of Petition Availability

    Science.gov (United States)

    2010-11-09

    ... National Oceanic and Atmospheric Administration RIN 0648-XA018 Eastern North Pacific Gray Whale; Notice of... Pacific population of gray whales (Eschrichtius robustus) as a depleted stock under the Marine Mammal... assessment report for Eastern North Pacific gray whales is available on the Internet at the following...

  13. The circulation of the eastern tropical Pacific: A review

    Science.gov (United States)

    Kessler, William S.

    2006-05-01

    During the 1950s and 1960s, an extensive field study and interpretive effort was made by researchers, primarily at the Scripps Institution of Oceanography, to sample and understand the physical oceanography of the eastern tropical Pacific. That work was inspired by the valuable fisheries of the region, the recent discovery of the equatorial undercurrent, and the growing realization of the importance of the El Niño phenomenon. Here we review what was learned in that effort, and integrate those findings with work published since then as well as additional diagnoses based on modern data sets. Unlike the central Pacific, where the winds are nearly zonal and the ocean properties and circulation are nearly independent of longitude, the eastern tropical Pacific is distinguished by wind forcing that is strongly influenced by the topography of the American continent. Its circulation is characterized by short zonal scales, permanent eddies and significant off-equatorial upwelling. Notably, the Costa Rica Dome and a thermocline bowl to its northwest are due to winds blowing through gaps in the Central American cordillera, which imprint their signatures on the ocean through linear Sverdrup dynamics. Strong annual modulation of the gap winds and the meridional oscillation of the Intertropical Convergence Zone generates a Rossby wave, superimposed on the direct forcing, that results in a southwestward-propagating annual thermocline signal accounting for major features of observed thermocline depth variations, including that of the Costa Rica Dome, the Tehuantepec bowl, and the ridge-trough system of the North Equatorial Countercurrent (NECC). Interannual variability of sea surface temperature (SST) and altimetric sea surface height signals suggests that the strengthening of the NECC observed in the central Pacific during El Niño events continues all the way to the coast, warming SST (by zonal advection) in a wider meridional band than the equatorially trapped thermocline

  14. Eastern tropical North Pacific coral radiocarbon reveals North Pacific Gyre Oscillation (NPGO) variability

    Science.gov (United States)

    Rafter, Patrick A.; Sanchez, Sara C.; Ferguson, Julie; Carriquiry, Jose D.; Druffel, Ellen R. M.; Villaescusa, J. A.; Southon, John R.

    2017-03-01

    Fluctuations in oceanic circulation and upwelling associated with the North Pacific Gyre Oscillation (NPGO) are the largest source of salinity and nutrient concentration variability across the Pacific basin. Recent observations suggest NPGO-like variability is intensifying, but longer, "pre-instrumental" records are required to improve our understanding of NPGO amplitude and phase change. Here, using measurements of coral skeletal chemistry from San Benedicto Island in the Eastern Tropical North Pacific (ETNP), we assess this region's suitability for reconstructing NPGO behavior. We find that coral geochemical proxy measurements of ETNP salinity and dissolved inorganic carbon radiocarbon (Δ14C) content reflect NPGO-driven gyre circulation and regional coastal upwelling. These results provide the basis for reconstructing NPGO-related ocean conditions hundreds of years prior to the modern observational record.

  15. Phospholipid synthesis rates in the eastern subtropical South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    B. A. S. Van Mooy

    2008-02-01

    Full Text Available Membrane lipid molecules are a major component of planktonic organisms and this is particularly true of the microbial picoplankton that dominate the open ocean; with their high surface-area to volume ratios, the synthesis of membrane lipids places a major demand on their overall cell metabolism. Specifically, the synthesis of cell membrane phospholipids creates a demand for the nutrient phosphorus, and we sought to refine our understanding of the role of phospholipids in the upper ocean phosphorus cycle. We measured the rates of phospholipid synthesis in a transect of the eastern subtropical South Pacific from Easter Island to Concepcion, Chile as part of the BIOSOPE program. Our approach combined standard phosphorus radiotracer incubations and lipid extraction methods. We found that phospholipid synthesis rates varied from less than 1 to greater than 200 pmol P L−1 h−1, and that phospholipid synthesis contributed between less than 5% to greater than 22% of the total PO43− incorporation rate. Changes in the percentage that phospholipid synthesis contributed to total PO43− uptake were strongly correlated with the ratio of primary production to bacterial production, which supported our hypothesis that heterotrophic bacteria were the primary agents of phospholipid synthesis. The spatial variation in phospholipid synthesis rates underscored the importance of heterotrophic bacteria in the phosphorus cycle of the eastern subtropical South Pacific, particularly the hyperoligotrophic South Pacific subtropical gyre.

  16. Contrasting Effects of Central Pacific and Eastern Pacific El Nino on Stratospheric Water Vapor

    Science.gov (United States)

    Garfinkel, Chaim I.; Hurwitz, Margaret M.; Oman, Luke D.; Waugh, Darryn W.

    2013-01-01

    Targeted experiments with a comprehensive chemistry-climate model are used to demonstrate that seasonality and the location of the peak warming of sea surface temperatures dictate the response of stratospheric water vapor to El Nino. In spring, El Nino events in which sea surface temperature anomalies peak in the eastern Pacific lead to a warming at the tropopause above the warm pool region, and subsequently to more stratospheric water vapor (consistent with previous work). However, in fall and in early winter, and also during El Nino events in which the sea surface temperature anomaly is found mainly in the central Pacific, the response is qualitatively different: temperature changes in the warm pool region are nonuniform and less water vapor enters the stratosphere. The difference in water vapor in the lower stratosphere between the two variants of El Nino approaches 0.3 ppmv, while the difference between the winter and spring responses exceeds 0.5 ppmv.

  17. Natal foraging philopatry in eastern Pacific hawksbill turtles.

    Science.gov (United States)

    Gaos, Alexander R; Lewison, Rebecca L; Jensen, Michael P; Liles, Michael J; Henriquez, Ana; Chavarria, Sofia; Pacheco, Carlos Mario; Valle, Melissa; Melero, David; Gadea, Velkiss; Altamirano, Eduardo; Torres, Perla; Vallejo, Felipe; Miranda, Cristina; LeMarie, Carolina; Lucero, Jesus; Oceguera, Karen; Chácon, Didiher; Fonseca, Luis; Abrego, Marino; Seminoff, Jeffrey A; Flores, Eric E; Llamas, Israel; Donadi, Rodrigo; Peña, Bernardo; Muñoz, Juan Pablo; Ruales, Daniela Alarcòn; Chaves, Jaime A; Otterstrom, Sarah; Zavala, Alan; Hart, Catherine E; Brittain, Rachel; Alfaro-Shigueto, Joanna; Mangel, Jeffrey; Yañez, Ingrid L; Dutton, Peter H

    2017-08-01

    The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles (Eretmochelys imbricata) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry.

  18. North Pacific Eastern Subtropical Mode Water simulation and future projection

    Institute of Scientific and Technical Information of China (English)

    XIA Ruibin; LIU Qinyu; XU Lixiao; LU Yiqun

    2015-01-01

    The present climate simulation and future projection of the Eastern Subtropical Mode Water (ESTMW) in the North Pacific are investigated based on the Geophysical Fluid Dynamics Laboratory Earth System Model (GFDL-ESM2M). Spatial patterns of the mixed layer depth (MLD) in the eastern subtropical North Pacific and the ESTMW are well simulated using this model. Compared with historical simulation, the ESTMW is produced at lighter isopycnal surfaces and its total volume is decreased in the RCP8.5 runs, because the subduction rate of the ESTMW decreases by 0.82×10−6 m/s during February–March. In addition, it is found that the lateral induction decreasing is approximately four times more than the Ekman pumping, and thus it plays a dominant role in the decreased subduction rate associated with global warming. Moreover, the MLD during February–March is banded shoaling in response to global warming, extending northeastward from the east of the Hawaii Islands (20°N, 155°W) to the west coast of North America (30°N, 125°W), with a max-imum shoaling of 50 m, and then leads to the lateral induction reduction. Meanwhile, the increased north-eastward surface warm current to the east of Hawaii helps strengthen of the local upper ocean stratification and induces the banded shoaling MLD under warmer climate. This new finding indicates that the ocean surface currents play an important role in the response of the MLD and the ESTMW to global warming.

  19. Training on Eastern Pacific tropical cyclones for Latin American students

    Science.gov (United States)

    Farfán, L. M.; Raga, G. B.

    2009-05-01

    Tropical cyclones are one of the most impressive atmospheric phenomena and their development in the Atlantic and Eastern Pacific basins has potential to affect several Latin-American and Caribbean countries, where human resources are limited. As part of an international research project, we are offering short courses based on the current understanding of tropical cyclones in the Eastern Pacific basin. Our main goal is to train students from higher-education institutions from various countries in Latin America. Key aspects are tropical cyclone formation and evolution, with particular emphasis on their development off the west coast of Mexico. Our approach includes lectures on tropical cyclone climatology and formation, dynamic and thermodynamic models, air-sea interaction and oceanic response, ocean waves and coastal impacts as well as variability and climate-related predictions. In particular, we use a best-track dataset issued by the United States National Hurricane Center and satellite observations to analyze convective patterns for the period 1970-2006. Case studies that resulted in landfall over northwestern Mexico are analyzed in more detail; this includes systems that developed during the 2006, 2007 and 2008 seasons. Additionally, we have organized a human-dimensions symposium to discuss socio-economic issues that are associated with the landfall of tropical cyclones. This includes coastal zone impact and flooding, the link between cyclones and water resources, the flow of weather and climate information from scientists to policy- makers, the role of emergency managers and decision makers, impact over health issues and the viewpoint of the insurance industry.

  20. Mechanisms for the cooling of the central eastern Pacific

    Science.gov (United States)

    Liu, Chunlei; Allan, Richard

    2017-04-01

    The sea surface temperature variation over the Central Eastern Pacific (CEP) controls the global mean surface temperature variation (Kosaka and Xie, 2013). The regional cooling over CEP is directly linked to the surface warming slowdown in last twenty years. It is important to understand the mechanisms of the CEP cooling in the warming climate in order to have a robust prediction of the future climate change. Previous studies showed the CEP cooling is related to the pronounced strengthening in Pacific trade winds over the past two decades, which is sufficient to account for the cooling of the CEP and a substantial slowdown in surface warming through increased subsurface ocean heat uptake in the Pacific shallow overturning cells and equatorial upwelling in the CEP (England et al., 2014). By analysing the cloud data, Zhou et al. (2016) showed the increase of the lower cloud cover (LCC) over the CEP area contributed to the cooling, resulting in positive local feedback and negative global feedback. Using the data from observations, ERA-Interim reanalysis and atmospheric climate simulations, our study shows that the increasing Latent Heat (LH) also plays an important role in the CEP cooling (Liu et al., 2015). After the sensitivity test using the bulk formula, it showed that both wind and total column water vapour content contribute to the cooling trends of the SST in CEP. The observed trends of the wind and LH in CEP also confirmed this. England et al. (2014) Recent intensification of wind-driven circulation in the Pacific and the ongoing warming hiatus, Nat. Clim. Change, 4, 222-227, doi:10.1038/nclimate2106. Kosaka, Y., and S. P. Xie (2013), Recent global-warming hiatus tied to equatorial Pacific surface cooling, Nature, 501, 403-407, doi:10.1038/nature12534. Liu et al. (2015) Combining satellite observations and reanalysis energy transports to estimate global net surface energy fluxes 1985-2012. J. Geophys. Res. , Atmospheres. ISSN 2169-8996 doi: 10.1002/2015JD

  1. Historical Eastern North Pacific Tropical Cyclone Tracks, 1949-2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This Historical Eastern North Pacific Tropical Cyclone Tracks file contains the six-hourly (0000, 0600, 1200, 1800 UTC) center locations and intensities for all...

  2. The ecology of xenophyophores (Protista) on eastern Pacific seamounts

    Science.gov (United States)

    Levin, Lisa A.; Thomas, Cynthia L.

    1988-12-01

    Large, agglutinating protozoans of the class Xenophyophorea are the dominant epifaunal organisms on soft and hard substrates of many bathyal seamounts in the eastern Pacific Ocean off Mexico. Observations made with the submersible Alvin and remotely towed camera sleds on 17 seamounts at 31°, 20°, 13° and 10°N revealed more than ten distinct xenophyophore test morphologies. Most of these appear to represent previously undescribed species. Reticulate forms are numerically dominant at 20°, 13° and 10°N. Xenophyophore abundances increase with decreasing latitude, being rare at 30°N, present at densities of 0.1-1.0 m -2 at 20° and 13°N and often exceeding 1.0 m -2 at 10°N, occasionally reaching 10-18 m -2. Highest concentrations are observed on caldera floors near the base of steep caldera walls, at depths between 1700 and 2500 m. Most individuals select sand-size pelagic foraminiferan tests (63-500 μm) and exclude pebble, silt and clay-size particles for test construction. Xenophyophore on seamounts modify the structure of metazoan communities and may play a role in maintenance of infaunal diversity. Twenty-seven xenophyophore tests were found to provide habitat for 16 major macrofaunal taxa (152 individuals) and three meiofaunal taxa (333 individuals). The presence of xenophyophores also enhances the abundance of isopods, tanaids, ophiuroids, nematodes and harpacticoid copepods dwelling in sediments surrounding the tests. Mobile megafauna are attracted to sediment beneath and adjacent to xenophyophores. We suggest that xenophyophores, which are abundant on many topographic features in deep water (e.g. guyots, trenches, canyons and continental slopes), are a functionally important component of deep-sea benthic communities and require further autecological and synecological investigation.

  3. Multiple distant origins for green sea turtles aggregating off Gorgona Island in the Colombian eastern Pacific.

    Directory of Open Access Journals (Sweden)

    Diego F Amorocho

    Full Text Available Mitochondrial DNA analyses have been useful for resolving maternal lineages and migratory behavior to foraging grounds (FG in sea turtles. However, little is known about source rookeries and haplotype composition of foraging green turtle aggregations in the southeastern Pacific. We used mitochondrial DNA control region sequences to identify the haplotype composition of 55 green turtles, Chelonia mydas, captured in foraging grounds of Gorgona National Park in the Colombian Pacific. Amplified fragments of the control region (457 bp revealed the presence of seven haplotypes, with haplotype (h and nucleotide (π diversities of h = 0.300±0.080 and π = 0.009±0.005 respectively. The most common haplotype was CMP4 observed in 83% of individuals, followed by CMP22 (5%. The genetic composition of the Gorgona foraging population primarily comprised haplotypes that have been found at eastern Pacific rookeries including Mexico and the Galapagos, as well as haplotypes of unknown stock origin that likely originated from more distant western Pacific rookeries. Mixed stock analysis suggests that the Gorgona FG population is comprised mostly of animals from the Galapagos rookery (80%. Lagrangian drifter data showed that movement of turtles along the eastern Pacific coast and eastward from distant western and central Pacific sites was possible through passive drift. Our results highlight the importance of this protected area for conservation management of green turtles recruited from distant sites along the eastern Pacific Ocean.

  4. A delayed action oscillator shared by biennial, interannual, and decadal signals in the Pacific Basin

    Science.gov (United States)

    White, Warren B.; Tourre, Y.M.; Barlow, M.; Dettinger, M.

    2003-01-01

    Biennial, interannual, and decadal signals in the Pacific basin are observed to share patterns and evolution in covarying sea surface temperature (SST), 18??C isotherm depth (Z18), zonal surface wind (ZSW), and wind stress curl (WSC) anomalies from 1955 to 1999. Each signal has warm SST anomalies propagating slowly eastward along the equator, generating westerly ZSW anomalies in their wake. These westerly ZSW anomalies produce cyclonic WSC anomalies off the equator which pump baroclinic Rossby waves in the western/central tropical North Pacific Ocean. These Rossby waves propagate westward, taking ???6, ???12, and ???36 months to reach the western boundary near ???7??N, ???12??N, and ???18??N on biennial, interannual, and decadal period scales, respectively. There, they reflect as equatorial coupled waves, propagating slowly eastward in covarying SST, Z18, and ZSW anomalies, taking ???6, ???12, and ???24 months to reach the central/eastern equatorial ocean. These equatorial coupled waves produce a delayed-negative feedback to the warm SST anomalies there. The decrease in Rossby wave phase speed with latitude, the increase in meridional scale of equatorial SST anomalies with period scale, and the associated increase in latitude of Rossby wave forcing are consistent with the delayed action oscillator (DAO) model used to explain El Nin??o. However, this is not true of the western-boundary reflection of Rossby waves into slow equatorial coupled waves. This requires modification of the extant DAO model. We construct a modified DAO model, demonstrating how the various mechanisms and the size and sources of their delays yield the resulting frequency of each signal.

  5. Feeding grounds of the eastern South Pacific humpback whale population include the South Orkney Islands

    Directory of Open Access Journals (Sweden)

    Luciano Dalla Rosa

    2012-03-01

    Full Text Available This paper reports on two photo-identified humpback whales (Megaptera novaeangliae that were sighted in different years in the proximity of the South Orkney Islands, at the boundary between the Scotia and Weddell seas (60°54.5'S—46°40.4'W and 60°42.6'S—45°33'W. One of the whales had been previously sighted off Ecuador, a breeding ground for the eastern South Pacific population. The other whale was subsequently resighted in Bransfield Strait, off the western Antarctic Peninsula, a well-documented feeding ground for the same population. These matches give support to a hypothesis that the area south of the South Orkney Islands is occupied by whales from the eastern South Pacific breeding stock. Consequently, we propose 40°W as a new longitudinal boundary between the feeding grounds associated with the eastern South Pacific and western South Atlantic breeding stocks.

  6. EFFECTS OF PACIFIC SSTA ON SUMMER PRECIPITATION OVER EASTERN CHINA, PART Ⅱ: NUMERICAL SIMULATIONS

    Institute of Scientific and Technical Information of China (English)

    YU Zheng-shou; SUN Zhao-bo; NI Dong-hong; ZENG Gang

    2007-01-01

    Based on an observational analysis, seven numerical experiments are designed to study the impacts of Pacific SSTA on summer precipitation over eastem China and relevant physical mechanism by NCAR CCM3. The numerical simulation results show that preceding winter SSTA in the Kuroshio region leads to summer precipitation anomaly over the Yangtze River valleys by modifying atmospheric general circulation over eastern Asia and middle-high latitude. West Pacific subtropical high is notably affected by preceding spring SSTA over the middle and east of Equator Pacific; SSTA of the central region of middle latitude in the corresponding period causes the summer rainfall anomaly over eastern China so as to trigger the atmospheric Eurasia-Pacific teleconnection pattern.

  7. Indo-Pacific sea surface temperature influences on failed consecutive rainy seasons over eastern Africa

    Science.gov (United States)

    Hoell, Andrew; Funk, Christopher C.

    2014-01-01

    Rainfall over eastern Africa (10°S–10°N; 35°E–50°E) is bimodal, with seasonal maxima during the "long rains" of March–April–May (MAM) and the "short rains" of October–November–December (OND). Below average precipitation during consecutive long and short rains seasons over eastern Africa can have devastating long-term impacts on water availability and agriculture. Here, we examine the forcing of drought during consecutive long and short rains seasons over eastern Africa by Indo-Pacific sea surface temperatures (SSTs). The forcing of eastern Africa precipitation and circulation by SSTs is tested using ten ensemble simulations of a global weather forecast model forced by 1950–2010 observed global SSTs. Since the 1980s, Indo-Pacific SSTs have forced more frequent droughts spanning consecutive long and short rains seasons over eastern Africa. The increased frequency of dry conditions is linked to warming SSTs over the Indo-west Pacific and to a lesser degree to Pacific Decadal Variability. During MAM, long-term warming of tropical west Pacific SSTs from 1950–2010 has forced statistically significant precipitation reductions over eastern Africa. The warming west Pacific SSTs have forced changes in the regional lower tropospheric circulation by weakening the Somali Jet, which has reduced moisture and rainfall over the Horn of Africa. During OND, reductions in precipitation over recent decades are oftentimes overshadowed by strong year-to-year precipitation variability forced by the Indian Ocean Dipole and the El Niño–Southern Oscillation.

  8. Indo-Pacific sea surface temperature influences on failed consecutive rainy seasons over eastern Africa

    Science.gov (United States)

    Hoell, Andrew; Funk, Chris

    2014-09-01

    Rainfall over eastern Africa (10°S-10°N; 35°E-50°E) is bimodal, with seasonal maxima during the "long rains" of March-April-May (MAM) and the "short rains" of October-November-December (OND). Below average precipitation during consecutive long and short rains seasons over eastern Africa can have devastating long-term impacts on water availability and agriculture. Here, we examine the forcing of drought during consecutive long and short rains seasons over eastern Africa by Indo-Pacific sea surface temperatures (SSTs). The forcing of eastern Africa precipitation and circulation by SSTs is tested using ten ensemble simulations of a global weather forecast model forced by 1950-2010 observed global SSTs. Since the 1980s, Indo-Pacific SSTs have forced more frequent droughts spanning consecutive long and short rains seasons over eastern Africa. The increased frequency of dry conditions is linked to warming SSTs over the Indo-west Pacific and to a lesser degree to Pacific Decadal Variability. During MAM, long-term warming of tropical west Pacific SSTs from 1950-2010 has forced statistically significant precipitation reductions over eastern Africa. The warming west Pacific SSTs have forced changes in the regional lower tropospheric circulation by weakening the Somali Jet, which has reduced moisture and rainfall over the Horn of Africa. During OND, reductions in precipitation over recent decades are oftentimes overshadowed by strong year-to-year precipitation variability forced by the Indian Ocean Dipole and the El Niño-Southern Oscillation.

  9. Iron-rich basal sediments from the eastern equatorial pacific: Leg 16, deep sea drilling project

    Science.gov (United States)

    Cronan, D.S.; Van Andel, T. H.; Ross, Heath G.; Dinkelman, M.G.; Bennett, R.H.; Bukry, D.; Charleston, S.; Kaneps, A.; Rodolfo, K.S.; Yeats, R.S.

    1972-01-01

    Iron-rich sediments chemically similar to those forming at present on the crest of the East Pacific Rise have been found just above basement at widely separated drill sites in the eastern equatorial Pacific, including three sites of Leg 16 of the Deep Sea Drilling Project. These sediments were probably formed when the basement was at the crest of this rise and have moved to their present location as a result of sea-floor spreading.

  10. Eastern Pacific tropical cyclones intensified by El Niño delivery of subsurface ocean heat.

    Science.gov (United States)

    Jin, F-F; Boucharel, J; Lin, I-I

    2014-12-04

    The El Niño Southern Oscillation (ENSO) creates strong variations in sea surface temperature in the eastern equatorial Pacific, leading to major climatic and societal impacts. In particular, ENSO influences the yearly variations of tropical cyclone (TC) activities in both the Pacific and Atlantic basins through atmospheric dynamical factors such as vertical wind shear and stability. Until recently, however, the direct ocean thermal control of ENSO on TCs has not been taken into consideration because of an apparent mismatch in both timing and location: ENSO peaks in winter and its surface warming occurs mostly along the Equator, a region without TC activity. Here we show that El Niño--the warm phase of an ENSO cycle--effectively discharges heat into the eastern North Pacific basin two to three seasons after its wintertime peak, leading to intensified TCs. This basin is characterized by abundant TC activity and is the second most active TC region in the world. As a result of the time involved in ocean transport, El Niño's equatorial subsurface 'heat reservoir', built up in boreal winter, appears in the eastern North Pacific several months later during peak TC season (boreal summer and autumn). By means of this delayed ocean transport mechanism, ENSO provides an additional heat supply favourable for the formation of strong hurricanes. This thermal control on intense TC variability has significant implications for seasonal predictions and long-term projections of TC activity over the eastern North Pacific.

  11. Elevated Glyoxal Concentrations over the Eastern Equatorial Pacific: A Direct Biogenic Source?

    Science.gov (United States)

    Zhang, R.; Wang, Y.; Lerot, C.

    2014-12-01

    Elevated atmospheric glyoxal (CHOCHO) was observed over the eastern equatorial Pacific by satellite and ship measurements. We investigated the source contributions through inverse modeling using GOME-2 observations (2007-2012) and the GEOS-Chem model. The observed high glyoxal to HCHO column ratio over the region indicates the potential presence of a direct source of glyoxal rather than secondary production. A bimodal seasonal cycle of glyoxal concentrations was found, providing further evidence for a biogenic origin of glyoxal emission. The estimate of the primary glyoxal emission over the eastern equatorial Pacific is 20-40Tg/yr, which is comparable to the previous estimate of the global continential glyoxal emission.

  12. 75 FR 70903 - Eastern North Pacific Gray Whale; Notice of Extension of Public Comment Period on Marine Mammal...

    Science.gov (United States)

    2010-11-19

    ... on the petition (75 FR 68756). That Federal Register notice began NMFS' 15-day public comment period... National Oceanic and Atmospheric Administration RIN 0648-XA018 Eastern North Pacific Gray Whale; Notice of... petition to designate the Eastern North Pacific population of gray whales (Eschrichtius robustus) as...

  13. Silicon stable isotope distribution traces Southern Ocean export of Si to the eastern South Pacific thermocline

    Science.gov (United States)

    de Souza, G. F.; Reynolds, B. C.; Johnson, G. C.; Bullister, J. L.; Bourdon, B.

    2012-11-01

    The cycling and transport of dissolved silicon (Si) in the ocean may be traced by its stable isotope composition, δ30Si. We present a dataset of δ30Si values along 103° W in the eastern South Pacific Ocean, ranging from the Antarctic Zone of the Southern Ocean (62° S) to the equatorial Pacific (12° S). At high southern latitudes, the uptake and associated isotope fractionation of Si by diatoms results in highly elevated δ30Si values (up to +3.2‰) in the summer mixed layer. High δ30Si values (+2‰) are also preserved in the high-latitude fossil winter mixed layer, documenting the efficient export of diatom opal beyond the maximum depth of winter convection. This elevated winter mixed layer δ30Si signature is introduced into the ocean interior by the subduction of Subantarctic Mode Water (SAMW) and Antarctic Intermediate Water (AAIW), whose northward spreading results in a strong isopycnal control on lower-thermocline and intermediate δ30Si values in the well-ventilated eastern South Pacific. Values of δ30Si are strongly conserved along SAMW and AAIW density levels as far north as 26° S, documenting the importance of the export of preformed Si from the surface Southern Ocean to lower latitudes. In contrast, in the equatorial Pacific, depressed δ30Si values in the mesopelagic ocean are observed, most likely documenting the combined influence of a North Pacific Si source as well as the accumulation of remineralized Si within the eastern equatorial Pacific shadow zone. At depth, δ30Si values in the South Pacific remain indistinguishable from deep Southern Ocean values of +1.25‰, even within Si-rich and oxygen-poor deep waters returning from the North Pacific. This homogeneity implies that the dissolution of opal plays a negligible role in altering the δ30Si value of deep waters as they traverse the deep Pacific Ocean.

  14. Dynamic mechanism of interannual zonal displacements of the eastern edge of the western Pacific warm pool

    Institute of Scientific and Technical Information of China (English)

    齐庆华; 张启龙; 侯一筠

    2010-01-01

    The eastern edge of the western Pacific warm pool (WPWP) in the upper layer (shallower than 50m) exhibits significant zonal displacements on interannual scale. Employing an intermediate ocean model, the dynamic mechanism for the interannual zonal displacement of the WPWP eastern edge in the upper layer is investigated by diagnosing the dynamic impacts of zonal current anomalies induced by wind, waves (Kelvin and Rossby waves), and their boundary reflections. The interannual zonal displacements of the WPWP e...

  15. Mortalities of eastern and pacific oyster larvae caused by the pathogens Vibrio coralliilyticus and Vibrio tubiashii

    Science.gov (United States)

    Vibrio tubiashii is reported to be a bacterial pathogen of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) and has been associated with major hatchery crashes, causing shortages in seed oysters for commercial shellfish producers. Another bacterium, Vibrio cora...

  16. Particulate silica and Si recycling in the surface waters of the Eastern Equatorial Pacific

    DEFF Research Database (Denmark)

    Adjou, Mohamed; Tréguer, Paul; Dumousseaud, Cynthia

    2011-01-01

    The distributions of biogenic and lithogenic silica concentrations and net silica production rates in the upper 120 m of the Eastern Equatorial Pacific (EEP) were examined in December 2004, on two transects situated at 110°W (4°N to 3°S) and along the equator (110°W to 140°W). Lithogenic silica (...

  17. Revision of Hydroides Gunnerus, 1768 (Polychaeta: Serpulidae) from the Eastern Pacific region and Hawaii

    NARCIS (Netherlands)

    Bastida-Zavala, J. Rolando; Hove, ten Harry A.

    2003-01-01

    A taxonomic revision of the Hydroides species (Polychaeta: Serpulidae) from the Eastern Pacific Ocean is presented. Twentyone taxa are described, of which two are widespread (H. diramphus Mörch, 1863 and H. elegans (Haswell, 1883)) and four are Amphiamerican (H. alatalateralis (Jones, 1962), H.

  18. Eastern equatorial Pacific Ocean T-S variations with El Nino

    Science.gov (United States)

    Wang, O.; Fukumori, I.; Lee, T.; Johnson, G. C.

    2004-01-01

    Temperature-Salinity (T-S) relationship variability in the pycnocline of the eastern equatorial Pacific Ocean (NINO3 region, 5 degrees S ??degrees N, 150 degrees W ?? degrees W) over the last two decades is investigated using observational data and model simulation.

  19. El Niño and coral larval dispersal across the eastern Pacific marine barrier

    Science.gov (United States)

    Wood, S.; Baums, I. B.; Paris, C. B.; Ridgwell, A.; Kessler, W. S.; Hendy, E. J.

    2016-08-01

    More than 5,000 km separates the frequently disturbed coral reefs of the Eastern Tropical Pacific (ETP) from western sources of population replenishment. It has been hypothesized that El Niño events facilitate eastward dispersal across this East Pacific Barrier (EPB). Here we present a biophysical coral larval dispersal model driven by 14.5 years of high-resolution surface ocean current data including the extreme 1997-1998 El Niño. We find no eastward cross-EPB connections over this period, which implies that ETP coral populations decimated by the 1998 bleaching event can only have recovered from eastern Pacific sources, in congruence with genetic data. Instead, rare connections between eastern and central Pacific reefs are simulated in a westward direction. Significant complexity and variability in the surface flows transporting larvae mean that generalized upper-ocean circulation patterns are poor descriptors of inter-regional connectivity, complicating the assessment of how climate change will impact coral gene flow Pacific wide.

  20. Mortalities of Eastern and Pacific oyster Larvae caused by the pathogens Vibrio coralliilyticus and Vibrio tubiashii.

    Science.gov (United States)

    Richards, Gary P; Watson, Michael A; Needleman, David S; Church, Karlee M; Häse, Claudia C

    2015-01-01

    Vibrio tubiashii is reported to be a bacterial pathogen of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) and has been associated with major hatchery crashes, causing shortages in seed oysters for commercial shellfish producers. Another bacterium, Vibrio coralliilyticus, a well-known coral pathogen, has recently been shown to elicit mortality in fish and shellfish. Several strains of V. coralliilyticus, such as ATCC 19105 and Pacific isolates RE22 and RE98, were misidentified as V. tubiashii until recently. We compared the mortalities caused by two V. tubiashii and four V. coralliilyticus strains in Eastern and Pacific oyster larvae. The 50% lethal dose (LD50) of V. coralliilyticus in Eastern oysters (defined here as the dose required to kill 50% of the population in 6 days) ranged from 1.1 × 10(4) to 3.0 × 10(4) CFU/ml seawater; strains RE98 and RE22 were the most virulent. This study shows that V. coralliilyticus causes mortality in Eastern oyster larvae. Results for Pacific oysters were similar, with LD50s between 1.2 × 10(4) and 4.0 × 10(4) CFU/ml. Vibrio tubiashii ATCC 19106 and ATCC 19109 were highly infectious toward Eastern oyster larvae but were essentially nonpathogenic toward healthy Pacific oyster larvae at dosages of ≥1.1 × 10(4) CFU/ml. These data, coupled with the fact that several isolates originally thought to be V. tubiashii are actually V. coralliilyticus, suggest that V. coralliilyticus has been a more significant pathogen for larval bivalve shellfish than V. tubiashii, particularly on the U.S. West Coast, contributing to substantial hatchery-associated morbidity and mortality in recent years.

  1. Vertical structure variability and equatorial waves during central Pacific and eastern Pacific El Ninos in a coupled general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Dewitte, B.; Thual, S. [LEGOS/IRD, Toulouse (France); Choi, J.; An, S.I. [Yonsei University, Seoul (Korea, Republic of)

    2012-06-15

    Recent studies report that two types of El Nino events have been observed. One is the cold tongue El Nino or Eastern Pacific El Nino (EP El Nino), which is characterized by relatively large sea surface temperature (SST) anomalies in the eastern Pacific, and the other is the warm pool El Nino (a.k.a. 'Central Pacific El Nino' (CP El Nino) or 'El Nino Modoki'), in which SST anomalies are confined to the central Pacific. Here the vertical structure variability of the periods during EP and CP is investigated based on the GFDL{sub C}M2.1 model in order to explain the difference in equatorial wave dynamics and associated negative feedback mechanisms. It is shown that the mean stratification in the vicinity of the thermocline of the central Pacific is reduced during CP El Nino, which favours the contribution of the gravest baroclinic mode relatively to the higher-order slower baroclinic mode. Energetic Kelvin and first-meridional Rossby wave are evidenced during the CP El Nino with distinctive amplitude and propagating characteristics according to their vertical structure (mostly first and second baroclinic modes). In particular, the first baroclinic mode during CP El Nino is associated to the ocean basin mode and participates to the recharge process during the whole El Nino cycle, whereas the second baroclinic mode is mostly driving the discharge process through the delayed oscillator mechanism. This may explain that the phase transition from warm to neutral/cold conditions during the CP El Nino is delayed and/or disrupted compared to the EP El Nino. Our results have implications for the interpretation of the variability during periods of high CP El Nino occurrence like the last decade. (orig.)

  2. Northern fulmars as biological monitors of trends of plastic pollution in the eastern North Pacific.

    Science.gov (United States)

    Avery-Gomm, Stephanie; O'Hara, Patrick D; Kleine, Lydia; Bowes, Victoria; Wilson, Laurie K; Barry, Karen L

    2012-09-01

    Marine plastic debris is a global issue, which highlights the need for internationally standardized methods of monitoring plastic pollution. The stomach contents of beached northern fulmar (Fulmarus glacialis) have proven a cost-effective biomonitor in Europe. However, recent information on northern fulmar plastic ingestion is lacking in the North Pacific. We quantified the stomach contents of 67 fulmars from beaches in the eastern North Pacific in 2009-2010 and found that 92.5% of fulmars had ingested an average of 36.8 pieces, or 0.385 g of plastic. Plastic ingestion in these fulmars is among the highest recorded globally. Compared to earlier studies in the North Pacific, our findings indicate an increase in plastic ingestion over the past 40 years. This study substantiates the use of northern fulmar as biomonitors of plastic pollution in the North Pacific and suggests that the high levels of plastic pollution in this region warrant further monitoring.

  3. Connection between the Eastern Subtropical Mode Water in the South Pacific Ocean and the ENSO cycle

    Science.gov (United States)

    Li, Z.

    2012-12-01

    Water subducted in the subtropics is intimately linked to the circulation in the Tropics through the interior mass communication and/or the western boundary, and could potentially affect climate variability on interannual and decadal time scales (Gu and Philander, 1997). The interior mass communication rate between the subtropical and equatorial ocean can be quantified in different ways. For example, Huang and Wang (2001) proposed a method of using the Sverdrup function to quantify the communication rate. Their method is used here to compute the meridional transport function below the Ekman layer in order to investigate the direct communication from the eastern STMW to the equatorial Pacific, and study the connection between the eastern STMW and the ENSO cycle. The western subtropical mode water, however, is less likely to directly participate in the subtropical-tropical exchange because they are mainly formed and confined to the recirculation region of the western subtropical gyre (Ladd and Thompson, 2000). The variability of the Subtropical Mode Water (STMW) formation in the South Pacific Ocean from 1980 to 2004 is investigated in this study, using a high-resolution numerical model and a 3D Lagrangian trajectory model. Variations of subduction rate in the mode waters are closely linked to the El Niño-Southern Oscillation (ENSO) cycle. The eastern STMW could potentially affect the ENSO cycle through the interior communication window that was identified from the virtual streamfunction. Its location and width closely related to the ENSO cycle. The deep westward penetration of the western edge of the window at the equatorial Pacific is evident during the 1998 La Niña event.; Zonal location of the interior communication window for eastern STMW, when the subducted water parcels reach the equatorial Pacific at 10oS. Solid gray (black) line represents the western (eastern) edge of the window.

  4. A dissolved cobalt plume in the oxygen minimum zone of the eastern tropical South Pacific

    Science.gov (United States)

    Hawco, Nicholas J.; Ohnemus, Daniel C.; Resing, Joseph A.; Twining, Benjamin S.; Saito, Mak A.

    2016-10-01

    Cobalt is a nutrient to phytoplankton, but knowledge about its biogeochemical cycling is limited, especially in the Pacific Ocean. Here, we report sections of dissolved cobalt and labile dissolved cobalt from the US GEOTRACES GP16 transect in the South Pacific. The cobalt distribution is closely tied to the extent and intensity of the oxygen minimum zone in the eastern South Pacific with highest concentrations measured at the oxycline near the Peru margin. Below 200 m, remineralization and circulation produce an inverse relationship between cobalt and dissolved oxygen that extends throughout the basin. Within the oxygen minimum zone, elevated concentrations of labile cobalt are generated by input from coastal sources and reduced scavenging at low O2. As these high cobalt waters are upwelled and advected offshore, phytoplankton export returns cobalt to low-oxygen water masses underneath. West of the Peru upwelling region, dissolved cobalt is less than 10 pM in the euphotic zone and strongly bound by organic ligands. Because the cobalt nutricline within the South Pacific gyre is deeper than in oligotrophic regions in the North and South Atlantic, cobalt involved in sustaining phytoplankton productivity in the gyre is heavily recycled and ultimately arrives from lateral transport of upwelled waters from the eastern margin. In contrast to large coastal inputs, atmospheric deposition and hydrothermal vents along the East Pacific Rise appear to be minor sources of cobalt. Overall, these results demonstrate that oxygen biogeochemistry exerts a strong influence on cobalt cycling.

  5. Evaluation of the eastern equatorial Pacific SST seasonal cycle in CMIP5 models

    Directory of Open Access Journals (Sweden)

    Z. Song

    2014-04-01

    Full Text Available The annual cycle of sea surface temperature (SST in the eastern equatorial Pacific (EEP with the largest amplitude in the tropical oceans is poorly represented in the coupled general circulation models (CGCMs of the Coupled Model Intercomparison Project phase 3 (CMIP3. In this study, 18 models from CMIP5 projects are evaluated in simulating the annual cycle in the EEP. Fourteen models are able to simulate the annual cycle, and four still show erroneous information in the simulation, which suggests that the performances of CGCMs have been improved. The results of multi-model ensemble (MME mean show that CMIP5 CGCMs can capture the annual cycle signal in the EEP with correlation coefficients up to 0.9. For amplitude simulations, EEP region 1 (EP1 near the eastern coast shows weaker results than observations due to the large warm SST bias from the southeastern tropical Pacific in the boreal autumn. In EEP region 2 (EP2 near the central equatorial Pacific, the simulated amplitudes are nearly the same as the observations because of the presence of a quasi-constant cold bias associated with poor cold tongue climatology simulation in the CGCMs. To improve CGCMs in the simulation of a realistic SST seasonal cycle, local and remote climatology SST biases that exist in both CMIP3 and CMIP5 CGCMs must be resolved at least for the simulation in the central equatorial Pacific and the southeastern tropical Pacific.

  6. Modes of hurricane activity variability in the eastern Pacific: Implications for the 2016 season

    Science.gov (United States)

    Boucharel, Julien; Jin, Fei-Fei; England, Matthew H.; Lin, I. I.

    2016-11-01

    A gridded product of accumulated cyclone energy (ACE) in the eastern Pacific is constructed to assess the dominant mode of tropical cyclone (TC) activity variability. Results of an empirical orthogonal function decomposition and regression analysis of environmental variables indicate that the two dominant modes of ACE variability (40% of the total variance) are related to different flavors of the El Niño-Southern Oscillation (ENSO). The first mode, more active during the later part of the hurricane season (September-November), is linked to the eastern Pacific El Niño through the delayed oceanic control associated with the recharge-discharge mechanism. The second mode, dominant in the early months of the hurricane season, is related to the central Pacific El Niño mode and the associated changes in atmospheric variability. A multilinear regression forecast model of the dominant principal components of ACE variability is then constructed. The wintertime subsurface state of the eastern equatorial Pacific (characterizing ENSO heat discharge), the east-west tilt of the thermocline (describing ENSO phase transition), the anomalous ocean surface conditions in the TC region in spring (portraying atmospheric changes induced by persistence of local surface anomalies), and the intraseasonal atmospheric variability in the western Pacific are found to be good predictors of TC activity. Results complement NOAA's official forecast by providing additional spatial and temporal information. They indicate a more active 2016 season ( 2 times the ACE mean) with a spatial expansion into the central Pacific associated with the heat discharge from the 2015/2016 El Niño.

  7. Invasive range expansion by the Humboldt squid, Dosidicus gigas, in the eastern North Pacific.

    Science.gov (United States)

    Zeidberg, Louis D; Robison, Bruce H

    2007-07-31

    A unique 16-year time series of deep video surveys in Monterey Bay reveals that the Humboldt squid, Dosidicus gigas, has substantially expanded its perennial geographic range in the eastern North Pacific by invading the waters off central California. This sustained range expansion coincides with changes in climate-linked oceanographic conditions and a reduction in competing top predators. It is also coincident with a decline in the abundance of Pacific hake, the most important commercial groundfish species off western North America. Recognizing the interactive effects of multiple changes in the environment is an issue of growing concern in ocean conservation and sustainability research.

  8. Gymnothorax phalarus, a new eastern Pacific moray eel (Pisces: Muraenidae

    Directory of Open Access Journals (Sweden)

    William A. Bussing

    1998-06-01

    Full Text Available Gymnothorax phalarus is described from 23 individuals taken in trawl and dredge collections made on the Pacific coast of Costa Rica. The new species is nearly always syntopic with a similar species, Gymnothorax equatorialis. The new moray is distinguished by its white-spotted pattern, uniserial, slightly serrated teeth in adults, four infraorbital pores and mean vertebral formula of 6-58-140. Of the total of 21 valid species of morays recorded from the Pacific coast of Costa Rica, only the new species and G. equatorialis form part of the trawl fishery as the remainder are almost entirely restricted to nearshore rocky habitats. The known range of G. phalarus is from Baja California to Peru.Gymnothorax phalarus se describe con base en 23 individuos de colecciones hechas por redes de arrastre y dragas en la costa Pacífica de Costa Rica. La especie nueva es casi siempre sintópica con la especie similar, Gymnothorax equatorialis. La nueva morena se distingue por su patrón de puntos blancos, dientes ligeramente aserrados y uniseriales en adultos, cuatro poros infraorbitales y MVF (Fórmula de Vértebras de 6-58-140. México a Perú.

  9. Silicon stable isotope distribution traces Southern Ocean export of Si to the eastern South Pacific thermocline

    Directory of Open Access Journals (Sweden)

    G. F. de Souza

    2012-06-01

    Full Text Available The cycling and transport of dissolved silicon (Si in the ocean may be traced by its stable isotope composition, δ30Si. We present a dataset of δ30Si values along 103° W in the eastern South Pacific Ocean, ranging from the Antarctic Zone of the Southern Ocean (62° S to the equatorial Pacific (12° S. At high southern latitudes, the uptake and associated isotope fractionation of Si by diatoms results in highly elevated δ30Si values (up to +3.2 ‰ in the summer mixed layer. The efficient export of diatom opal to depths inaccessible to annual winter convection is reflected by high δ30Si values (+2 ‰ preserved in high-latitude winter mixed layers. These elevated δ30Si values are introduced into the ocean interior by the subduction of Subantarctic Mode Water (SAMW and Antarctic Intermediate Water (AAIW, whose northward spreading results in a strong isopycnal control on lower-thermocline and intermediate δ30Si values in the well-ventilated eastern South Pacific. Values of δ30Si are strongly conserved along SAMW and AAIW density levels as far north as 26° S, documenting the importance of the export of preformed Si from the surface Southern Ocean to lower latitudes. In contrast, in the equatorial Pacific, depressed δ30Si values in the mesopelagic ocean are observed, most likely documenting the combined influence of a North Pacific Si source as well as the accumulation of remineralized Si within the eastern equatorial Pacific shadow zone. At depth, δ30Si values in the South Pacific remain indistinguishable from deep Southern Ocean values of +1.25 ‰, even within Si-rich and oxygen-poor deep waters returning from the North Pacific. This homogeneity implies that the dissolution of opal plays a negligible role in altering the δ30Si value of deep waters as they traverse the deep Pacific Ocean.

  10. Tropical Cyclone Exposure for U.S. waters within the Eastern Pacific Ocean basin, 1900-2013

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent modeled, historical exposure of U.S. offshore and coastal waters to tropical cyclone activity within the Eastern Pacific Ocean basin. BOEM Outer...

  11. CTD and Water Chemistry data of the Eastern Pacific Redox Experiment of May - June 2000 (NODC Accession 0000833)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Eastern Pacific Redox Experiment (EPREX) took place 24 May to 28 June 2000 on the R/V Roger Revelle. The first station was at the Hawaii Ocean Time Series...

  12. AFSC/RACE/GAP/Conrath: Notes on the Reproductive Biology of Female Salmon Sharks in the Eastern North Pacific Ocean

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Little information has previously been published on the reproductive biology of the salmon shark in the Eastern North Pacific ocean. This data set incorporates basic...

  13. AFSC/NMML: Shore-based counts of the Eastern North Pacific gray whale stock from central California, 1967 - 2007

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Fisheries Service (NMFS) has conducted shore-based counts of the Eastern North Pacific stock of gray whales (Eschrichtius robustus) 26 years from...

  14. Oxygen distribution and aerobic respiration in the north and south eastern tropical Pacific oxygen minimum zones

    DEFF Research Database (Denmark)

    Tiano, Laura; Garcia-Robledo, Emilio; Dalsgaard, Tage

    2014-01-01

    Highly sensitive STOX O-2 sensors were used for determination of in situ O-2 distribution in the eastern tropical north and south Pacific oxygen minimum zones (ETN/SP OMZs), as well as for laboratory determination of O-2 uptake rates of water masses at various depths within these OMZs. Oxygen...... was generally below the detection limit (few nmol L-1) in the core of both OMZs, suggesting the presence of vast volumes of functionally anoxic waters in the eastern Pacific Ocean. Oxygen was often not detectable in the deep secondary chlorophyll maximum found at some locations, but other secondary maxima...... efficiently at extremely low oxygen concentrations with apparent half-saturation concentrations (K-m values) ranging from about 10 to about 200 nmol L-1. (C) 2014 The Authors. Published by Elsevier Ltd....

  15. The feeding habits of slope dwelling macrourid fishes in the eastern North Pacific

    Science.gov (United States)

    Drazen, Jeffrey C.; Buckley, Troy W.; Hoff, Gerald R.

    2001-03-01

    The diet of slope dwelling macrourid fishes in the eastern North Pacific is poorly known. We collected several hundred stomach samples to investigate the feeding habits of Coryphaenoides acrolepis and Albatrossia pectoralis, the two dominant slope dwelling macrourids off the continental United States. Coryphaenoides acrolepis exhibited a pronounced ontogenetic shift in diet. Specimens 15 cm with scavenged food constituting approximately 20% of the weight of total prey and occurring in approximately 20% of fish 21-29 cm. Albatrossia pectoralis consumed primarily midwater fish and squid, and we believe that it feeds in the water column. There were significant differences between the diets of A. pectoralis and C. acrolepis suggesting some degree of niche separation between macrourid species on the continental slope of the eastern North Pacific. Both species are at the top of the food web on the upper continental slope and, because of their abundance, may exert significant pressures on their prey populations.

  16. A Probabilistic Model of Illegal Drug Trafficking Operations in the Eastern Pacific and Caribbean Sea

    Science.gov (United States)

    2013-09-01

    Illicit drug - trafficking is a major concern of the United States and is a primary pillar of President Barack Obama’s Strategy to Combat Transnational...Organized Crime. In the eastern Pacific and Caribbean Sea, drug - trafficking organizations operate a variety of vessels to transit drugs from South...interdicts illegal drug - trafficking in this region. In this thesis, we develop a probability model based on intelligence inputs to generate a spatial

  17. Status of the eastern Pacific agujon needlefish Tylosurus pacificusz (Steindachner, 1876) (Beloniformes: Belonidae)

    OpenAIRE

    Collette, Bruce B.; Branford, Heidi M.

    2016-01-01

    Tylosurus pacificus (Steindachner, 1876) is confirmed to have full species rank based on: 1) sympatry with T. acus melanotus at Isla Gorgona and in Panamá; 2) level of morphological differentiation in numbers of vertebrae, dorsal and anal fin rays; and 3) level of mtDNAdifferentiation. The eastern Pacific agujon needlefish is found from the Gulf of California, Mexico, to Peru, including the Galápagos Islands. Se confirma que Tylosurus pacificus (Steindachner, 1876) tiene el rango de especi...

  18. Radiostrontium monitoring of bivalves from the Pacific coast of eastern Japan.

    Science.gov (United States)

    Karube, Zin'ichi; Inuzuka, Yoko; Tanaka, Atsushi; Kurishima, Katsuaki; Kihou, Nobuharu; Shibata, Yasuyuki

    2016-09-01

    In early April 2011, radiostrontium was accidentally released from the Fukushima Daiichi Nuclear Power Plant to the Pacific coast of eastern Japan. We developed a simple procedure to analyze radiostrontium levels in marine mussels (Septifer virgatus) and seawater using crown ether (Sr Resin; Eichrom). Then, we used our method to describe the spatial and temporal distribution of radiostrontium in mussels and seawater on the Pacific coast of eastern Japan from 2011 to 2013 and for 2015. Activity of (90)Sr in mussels and seawater decreased with distance from the Fukushima Daiichi Nuclear Power Plant and between 2011 and 2013 tended to be higher in areas south of the Fukushima Daiichi Nuclear Power Plant than to the north of it. Activity in mussels and seawater also tended to decrease from 2011 to 2013 and by 2015 had reached levels experienced prior to the Fukushima accident. Our results suggest that radiostrontium discharged from the Fukushima Daiichi Nuclear Power Plant was dispersed by coastal currents in a southerly direction along the Pacific coast of eastern Japan from 2011 to 2013, following which its activity decreased to background levels by 2015.

  19. First record in the Tropical Eastern Pacific of the exotic species Ficopomatus uschakovi (Polychaeta, Serpulidae

    Directory of Open Access Journals (Sweden)

    Rolando Bastida Zavala

    2012-11-01

    Full Text Available The exotic Indo-West-Pacific species, Ficopomatus uschakovi (Polychaeta, Serpulidae is recorded for the first time in the Tropical Eastern Pacific from two sites in La Encrucijada Biosphere Reserve, Chiapas, a coastal lagoon in the Pacific south of Mexico. The means of dispersal of this serpulid species still remains unclear, as the nearest port (Puerto Chiapas is 70 km to the south, and there are no port installations or shrimp cultures in the lagoon. The record of this serpulid species, apparently widely distributed in this coastal lagoon, has implications regarding possible effects on the brackish-water ecosystem, since the invasion event very well may have occurred several years ago. It is recommended that an exhaustive study be carried out in the coastal lagoons of Chiapas to evaluate the real distribution and the effects of this invasive species on the ecosystem. A complete description, including photographs and drawings, is provided.

  20. First record in the Tropical Eastern Pacific of the exotic species Ficopomatus uschakovi (Polychaeta, Serpulidae).

    Science.gov (United States)

    Bastida-Zavala, Rolando; García-Madrigal, Socorro

    2012-01-01

    The exotic Indo-West-Pacific species, Ficopomatus uschakovi (Polychaeta, Serpulidae) is recorded for the first time in the Tropical Eastern Pacific from two sites in La Encrucijada Biosphere Reserve, Chiapas, a coastal lagoon in the Pacific south of Mexico. The means of dispersal of this serpulid species still remains unclear, as the nearest port (Puerto Chiapas) is 70 km to the south, and there are no port installations or shrimp cultures in the lagoon. The record of this serpulid species, apparently widely distributed in this coastal lagoon, has implications regarding possible effects on the brackish-water ecosystem, since the invasion event very well may have occurred several years ago. It is recommended that an exhaustive study be carried out in the coastal lagoons of Chiapas to evaluate the real distribution and the effects of this invasive species on the ecosystem. A complete description, including photographs and drawings, is provided.

  1. First record in the Tropical Eastern Pacific of the exotic species Ficopomatus uschakovi (Polychaeta, Serpulidae)

    Science.gov (United States)

    Bastida-Zavala, Rolando; García-Madrigal, Socorro

    2012-01-01

    Abstract The exotic Indo-West-Pacific species, Ficopomatus uschakovi (Polychaeta, Serpulidae) is recorded for the first time in the Tropical Eastern Pacific from two sites in La Encrucijada Biosphere Reserve, Chiapas, a coastal lagoon in the Pacific south of Mexico. The means of dispersal of this serpulid species still remains unclear, as the nearest port (Puerto Chiapas) is 70 km to the south, and there are no port installations or shrimp cultures in the lagoon. The record of this serpulid species, apparently widely distributed in this coastal lagoon, has implications regarding possible effects on the brackish-water ecosystem, since the invasion event very well may have occurred several years ago. It is recommended that an exhaustive study be carried out in the coastal lagoons of Chiapas to evaluate the real distribution and the effects of this invasive species on the ecosystem. A complete description, including photographs and drawings, is provided. PMID:23226707

  2. Estimating historical eastern North Pacific blue whale catches using spatial calling patterns.

    Directory of Open Access Journals (Sweden)

    Cole C Monnahan

    Full Text Available Blue whales (Balaenoptera musculus were exploited extensively around the world and remain endangered. In the North Pacific their population structure is unclear and current status unknown, with the exception of a well-studied eastern North Pacific (ENP population. Despite existing abundance estimates for the ENP population, it is difficult to estimate pre-exploitation abundance levels and gauge their recovery because historical catches of the ENP population are difficult to separate from catches of other populations in the North Pacific. We collated previously unreported Soviet catches and combined these with known catches to form the most current estimates of North Pacific blue whale catches. We split these conflated catches using recorded acoustic calls from throughout the North Pacific, the knowledge that the ENP population produces a different call than blue whales in the western North Pacific (WNP. The catches were split by estimating spatiotemporal occurrence of blue whales with generalized additive models fitted to acoustic call patterns, which predict the probability a catch belonged to the ENP population based on the proportion of calls of each population recorded by latitude, longitude, and month. When applied to the conflated historical catches, which totaled 9,773, we estimate that ENP blue whale catches totaled 3,411 (95% range 2,593 to 4,114 from 1905-1971, and amounted to 35% (95% range 27% to 42% of all catches in the North Pacific. Thus most catches in the North Pacific were for WNP blue whales, totaling 6,362 (95% range 5,659 to 7,180. The uncertainty in the acoustic data influence the results substantially more than uncertainty in catch locations and dates, but the results are fairly insensitive to the ecological assumptions made in the analysis. The results of this study provide information for future studies investigating the recovery of these populations and the impact of continuing and future sources of anthropogenic

  3. Estimating historical eastern North Pacific blue whale catches using spatial calling patterns.

    Science.gov (United States)

    Monnahan, Cole C; Branch, Trevor A; Stafford, Kathleen M; Ivashchenko, Yulia V; Oleson, Erin M

    2014-01-01

    Blue whales (Balaenoptera musculus) were exploited extensively around the world and remain endangered. In the North Pacific their population structure is unclear and current status unknown, with the exception of a well-studied eastern North Pacific (ENP) population. Despite existing abundance estimates for the ENP population, it is difficult to estimate pre-exploitation abundance levels and gauge their recovery because historical catches of the ENP population are difficult to separate from catches of other populations in the North Pacific. We collated previously unreported Soviet catches and combined these with known catches to form the most current estimates of North Pacific blue whale catches. We split these conflated catches using recorded acoustic calls from throughout the North Pacific, the knowledge that the ENP population produces a different call than blue whales in the western North Pacific (WNP). The catches were split by estimating spatiotemporal occurrence of blue whales with generalized additive models fitted to acoustic call patterns, which predict the probability a catch belonged to the ENP population based on the proportion of calls of each population recorded by latitude, longitude, and month. When applied to the conflated historical catches, which totaled 9,773, we estimate that ENP blue whale catches totaled 3,411 (95% range 2,593 to 4,114) from 1905-1971, and amounted to 35% (95% range 27% to 42%) of all catches in the North Pacific. Thus most catches in the North Pacific were for WNP blue whales, totaling 6,362 (95% range 5,659 to 7,180). The uncertainty in the acoustic data influence the results substantially more than uncertainty in catch locations and dates, but the results are fairly insensitive to the ecological assumptions made in the analysis. The results of this study provide information for future studies investigating the recovery of these populations and the impact of continuing and future sources of anthropogenic mortality.

  4. Global Shared Service Trends in the Central and Eastern European Markets

    Directory of Open Access Journals (Sweden)

    Róbert MARCINIAK

    2014-10-01

    Full Text Available The main objective of the research is to disclose what kind of trends are present in the global business service markets and which appear in the Central and Eastern European (CEE business market. The research determines the most important business service trends that emerged in shared service organizations in the CEE region.

  5. Global Shared Service Trends in the Central and Eastern European Markets

    OpenAIRE

    Róbert MARCINIAK

    2014-01-01

    The main objective of the research is to disclose what kind of trends are present in the global business service markets and which appear in the Central and Eastern European (CEE) business market. The research determines the most important business service trends that emerged in shared service organizations in the CEE region.

  6. Contrasting the eastern Pacific El Niño and the central Pacific El Niño: process-based feedback attribution

    Science.gov (United States)

    Hu, Xiaoming; Yang, Song; Cai, Ming

    2016-10-01

    This paper examines the roles of radiative and non-radiative air-sea coupled thermodynamic processes in modifying sea surface temperature (SST) anomalies driven by (air-sea coupled) oceanic dynamic processes, focusing on their contributions to the key differences between the eastern Pacific (EP) El Niño and the central Pacific (CP) El Niño. The attribution is achieved by decomposing SST anomalies into partial temperature anomalies due to individual processes using a coupled atmosphere-surface climate feedback-response analysis method. Oceanic processes induce warming from the central to the eastern equatorial Pacific and cooling over the western basin with a maximum warming center in the central Pacific for both types of El Niño. The processes that act to oppose the oceanic process-induced SST anomalies are surface latent heat flux, sensible heat flux, cloud, and atmospheric dynamic feedbacks, referred to as negative-feedback processes. The cooling due to each of the four negative-feedback processes is the strongest in the region where the initial warming due to oceanic processes is the largest. Water-vapor feedback is the sole process that acts to enhance the initial warming induced by oceanic processes. The increase in atmospheric water vapor over the eastern Pacific is much stronger for the EP El Niño than for the CP El Niño. It is the strong water-vapor feedback over the eastern Pacific and the strong negative feedbacks over the central equatorial Pacific that help to relocate the maximum warming center from the central Pacific to the eastern basin for the EP El Niño.

  7. 78 FR 23634 - Union Pacific Railroad Company-Trackage Rights Exemption-Elgin, Joliet and Eastern Railway Company

    Science.gov (United States)

    2013-04-19

    ... Surface Transportation Board Union Pacific Railroad Company--Trackage Rights Exemption--Elgin, Joliet and Eastern Railway Company Pursuant to a written trackage rights agreement dated December 18, 2012, Elgin, Joliet and Eastern Railway Company (EJ&E) \\1\\ has agreed to grant overhead trackage rights to Union...

  8. Possible Ballast Water Transfer of Lionfish to the Eastern Pacific Ocean.

    Science.gov (United States)

    MacIsaac, Hugh J; De Roy, Emma M; Leung, Brian; Grgicak-Mannion, Alice; Ruiz, Gregory M

    2016-01-01

    The Indo-Pacific Red Lionfish was first reported off the Florida coast in 1985, following which it has spread across much of the SE USA, Gulf of Mexico, and Caribbean Sea. Lionfish negatively impact fish and invertebrate assemblages and abundances, thus further spread is cause for concern. To date, the fish has not been reported on the Pacific coast of North or Central America. Here we examine the possibility of ballast water transfer of lionfish from colonized areas in the Atlantic Ocean to USA ports on the Pacific coast. Over an eight-year period, we documented 27 commercial vessel-trips in which ballast water was loaded in colonized sites and later discharged untreated into Pacific coast ports in the USA. California had the highest number of discharges including San Francisco Bay and Los Angeles-Long Beach. A species distribution model suggests that the probability of lionfish establishment is low for the western USA, Colombia and Panama, low to medium for Costa Rica, Nicaragua, El Salvador and Guatemala, medium to high for mainland Ecuador, and very high for western Mexico, Peru and the Galapagos Islands. Given the species' intolerance of freshwater conditions, we propose that ballast water exchange be conducted in Gatún Lake, Panama for western-bound vessels carrying 'risky' ballast water to prevent invasion of the eastern Pacific Ocean.

  9. Convection and Easterly Waves Observed in the Eastern Pacific ITCZ During EPIC2001

    Science.gov (United States)

    Petersen, Walter A.; Cifelli, Robert; Boccippio, Dennis J.; Rutledge, Steven A.; Arnold, James E. (Technical Monitor)

    2002-01-01

    During the last three weeks of September 2001, the East Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System (EPIC2001) intensive field campaign focused on studies of deep convection in the ITCZ-cold tongue complex over the Mexican warm-pool region (10 deg. N 95 deg. W) of the eastern Pacific Ocean. Major observational platforms deployed during this phase of EPIC2001 included two ships, the NOAA R/V Ronald H. Brown and the NSF R/V Horizon, and two research aircraft including a NOAA P-3 and the NCAR C-130. This study utilizes new C-band Doppler radar and sounding observations collected aboard the R/V Ronald Brown to describe the 4-D structure of ITCZ convection as a function of the environmental forcing and phase of 3-5 day easterly wave passages. Three distinct easterly wave passages occurred during EPIC2001. Each wave originated in the eastern Atlantic Ocean and after moving over Central America and into the eastern Pacific, were easily identified in time-height profiles of wind and thermodynamic data collected at the position of the R/V Brown. In all cases, the wave trough axes (as defined by changes in the meridional and zonal wind direction and changes in pressure altitude) exhibited relatively weak shear at low to mid-levels and tilted westward with height. The humidity profile in each wave did not exhibit as great a tilt in the vertical as the trough axes. Consistent with previous studies of westward tilting waves over the western Pacific Ocean, peaks in radar diagnosed rainfall tended to lead the passage of the surface wave trough by 0-2 days.

  10. Convection and Easterly Waves Observed in the Eastern Pacific ITCZ During EPIC2001

    Science.gov (United States)

    Petersen, Walter A.; Cifelli, Robert; Boccippio, Dennis J.; Rutledge, Steven A.; Arnold, James E. (Technical Monitor)

    2002-01-01

    During the last three weeks of September 2001, the East Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System (EPIC2001) intensive field campaign focused on studies of deep convection in the ITCZ-cold tongue complex over the Mexican warm-pool region (10 deg. N 95 deg. W) of the eastern Pacific Ocean. Major observational platforms deployed during this phase of EPIC2001 included two ships, the NOAA R/V Ronald H. Brown and the NSF R/V Horizon, and two research aircraft including a NOAA P-3 and the NCAR C-130. This study utilizes new C-band Doppler radar and sounding observations collected aboard the R/V Ronald Brown to describe the 4-D structure of ITCZ convection as a function of the environmental forcing and phase of 3-5 day easterly wave passages. Three distinct easterly wave passages occurred during EPIC2001. Each wave originated in the eastern Atlantic Ocean and after moving over Central America and into the eastern Pacific, were easily identified in time-height profiles of wind and thermodynamic data collected at the position of the R/V Brown. In all cases, the wave trough axes (as defined by changes in the meridional and zonal wind direction and changes in pressure altitude) exhibited relatively weak shear at low to mid-levels and tilted westward with height. The humidity profile in each wave did not exhibit as great a tilt in the vertical as the trough axes. Consistent with previous studies of westward tilting waves over the western Pacific Ocean, peaks in radar diagnosed rainfall tended to lead the passage of the surface wave trough by 0-2 days.

  11. Examination of Health Effects and Long-Term Impacts of Deployments of Multiple Tag Types on Blue, Humpback, and Gray Whales in the Eastern North Pacific

    Science.gov (United States)

    2015-09-30

    deployments of multiple tag types on blue, humpback, and gray whales in the eastern North Pacific John Calambokidis Cascadia Research Collective 218...large whales including blue, humpback, and gray whales by conducting long term follow up of previously tagged individuals in the eastern North Pacific...humpback, and gray whales in the eastern North Pacific and our extensive monitoring of these populations. Despite extensive use of implant tags for more

  12. Main factors determining bioerosion patterns on rocky cliffs in a drowned valley estuary in the Colombian Pacific (Eastern Tropical Pacific)

    Science.gov (United States)

    Cobo-Viveros, Alba Marina; Cantera-Kintz, Jaime Ricardo

    2015-10-01

    Bioerosion is an important process that destroys coastal rocks in the tropics. However, the rates at which this process occurs, the organisms involved, and the dynamics of rocky cliffs in tropical latitudes have been less studied than in temperate and subtropical latitudes. To contribute to the knowledge of the bioerosion process in rocky cliffs on the Pacific coast of Colombia (Eastern Tropical Pacific) we compared: 1) boring volume, 2) grain size distribution of the rocks, and 3) rock porosity, across three tidal zones of two cliffs with different wave exposure; these factors were related to the bioeroding community found. We observed that cliffs that were not exposed to wave action (IC, internal cliffs) exhibited high percentages of clays in their grain size composition, and a greater porosity (47.62%) and perforation (15.86%) than exposed cliffs (EC, external cliffs). However, IC also exhibited less diversity and abundance of bioeroding species (22 species and 314 individuals, respectively) compared to the values found in EC (41.11%, 14.34%, 32 and 491, respectively). The most abundant bioeroders were Petrolisthes zacae in IC and Pachygrapsus transversus in EC. Our findings show that the tidal zone is the common factor controlling bioerosion on both cliffs; in addition to the abundance of bioeroders on IC and the number of bioeroding species on EC. The integration of geology, sedimentology, and biology allows us to obtain a more comprehensive view of the patterns and trends in the process of bioerosion.

  13. Consolidating newborn screening efforts in the Asia Pacific region : Networking and shared education.

    Science.gov (United States)

    Padilla, Carmencita David; Therrell, Bradford L

    2012-01-01

    Many of the countries in the Asia Pacific Region, particularly those with depressed and developing economies, are just initiating newborn screening programs for selected metabolic and other congenital disorders. The cultural, geographic, language, and economic differences that exist throughout the region add to the challenges of developing sustainable newborn screening systems. There are currently more developing programs than developed programs within the region. Newborn screening activities in the Asia Pacific Region are particularly important since births there account for approximately half of the world's births. To date, there have been two workshops to facilitate formation of the Asia Pacific Newborn Screening Collaboratives. The 1st Workshop on Consolidating Newborn Screening Efforts in the Asia Pacific Region occurred in Cebu, Philippines, on March 30-April 1, 2008, as a satellite meeting to the 7th Asia Pacific Conference on Human Genetics. The second workshop was held on June 4-5, 2010, in Manila, Philippines. Workshop participants included key policy-makers, service providers, researchers, and consumer advocates from 11 countries with 50% or less newborn screening coverage. Expert lectures included experiences in the United States and the Netherlands, international quality assurance activities and ongoing and potential research activities. Additional meeting support was provided by the U.S. National Institutes of Health, the Centers for Disease Control and Prevention, the U.S. National Newborn Screening and Genetics Resource Center, the International Society for Neonatal Screening, and the March of Dimes. As part of both meeting activities, participants shared individual experiences in program implementation with formal updates of screening information for each country. This report reviews the activities and country reports from two Workshops on Consolidating Newborn Screening Efforts in the Asia Pacific Region with emphasis on the second workshop. It

  14. Eastern Pacific cooling and Atlantic overturning circulation during the last deglaciation.

    Science.gov (United States)

    Kienast, Markus; Kienast, Stephanie S; Calvert, Stephen E; Eglinton, Timothy I; Mollenhauer, Gesine; François, Roger; Mix, Alan C

    2006-10-19

    Surface ocean conditions in the equatorial Pacific Ocean could hold the clue to whether millennial-scale global climate change during glacial times was initiated through tropical ocean-atmosphere feedbacks or by changes in the Atlantic thermohaline circulation. North Atlantic cold periods during Heinrich events and millennial-scale cold events (stadials) have been linked with climatic changes in the tropical Atlantic Ocean and South America, as well as the Indian and East Asian monsoon systems, but not with tropical Pacific sea surface temperatures. Here we present a high-resolution record of sea surface temperatures in the eastern tropical Pacific derived from alkenone unsaturation measurements. Our data show a temperature drop of approximately 1 degrees C, synchronous (within dating uncertainties) with the shutdown of the Atlantic meridional overturning circulation during Heinrich event 1, and a smaller temperature drop of approximately 0.5 degrees C synchronous with the smaller reduction in the overturning circulation during the Younger Dryas event. Both cold events coincide with maxima in surface ocean productivity as inferred from 230Th-normalized carbon burial fluxes, suggesting increased upwelling at the time. From the concurrence of equatorial Pacific cooling with the two North Atlantic cold periods during deglaciation, we conclude that these millennial-scale climate changes were probably driven by a reorganization of the oceans' thermohaline circulation, although possibly amplified by tropical ocean-atmosphere interaction as suggested before.

  15. Diversity of culturable filamentous Ascomycetes in the eastern South Pacific Ocean off Chile.

    Science.gov (United States)

    Vera, Jeanett; Gutiérrez, Marcelo H; Palfner, Götz; Pantoja, Silvio

    2017-08-01

    Our study reports the diversity of culturable mycoplankton in the eastern South Pacific Ocean off Chile to contribute with novel knowledge on taxonomy of filamentous fungi isolated from distinct physicochemical and biological marine environments. We characterized spatial distribution of isolates, evaluated their viability and assessed the influence of organic substrate availability on fungal development. Thirty-nine Operational Taxonomic Units were identified from 99 fungal strains isolated from coastal and oceanic waters by using Automatic Barcode Gap Discovery. All Operational Taxonomic Units belonged to phylum Ascomycota and orders Eurotiales, Dothideales, Sordariales and Hypocreales, mainly Penicillium sp. (82%); 11 sequences did not match existing species in GenBank, suggesting occurrence of novel fungal taxa. Our results suggest that fungal communities in the South Pacific Ocean off Chile appear to thrive in a wide range of environmental conditions in the ocean and that substrate availability may be a factor influencing fungal viability in the ocean.

  16. Model Simulation of the Eastern Tropical South Pacific Oxygen Minimum Zone during the Holocene

    Science.gov (United States)

    Schneider, Birgit; Segschneider, Joachim; Xu, Xu; Park, Wonsun; Latif, Mojib

    2016-04-01

    The intensification/expansion of the tropical oxygen minimum zones (OMZs), as observed during the last decades, is usually assigned to anthropogenic climate change. However, natural variability may also affect OMZ variations. To assess the amplitude of natural (millennial-scale) variability in the oxygen minimum zone in the Eastern Tropical South Pacific (ETSP), a global coupled climate-ocean biogeochemical model has been applied to the mid-Holocene (approx. 6 kyrs BP). We find that during the mid-Holocene, the ETSP OMZ may have been better ventilated than today, which is entirely due to ocean circulation effects in the model. The enhanced ventilation is overriding the effect of increased biological production which in large parts of the equatorial Pacific, is driving oxygen towards lower values. The model result is in qualitative agreement with proxy data.

  17. Clipperton Atoll (eastern Pacific): oceanography, geomorphology, reef-building coral ecology and biogeography

    Science.gov (United States)

    Glynn, P. W.; Veron, J. E. N.; Wellington, G. M.

    1996-06-01

    Coral reef geomorphology and community composition were investigated in the tropical northeastern Pacific during April 1994. Three areas were surveyed in the Revillagigedo Islands (Mexico), and an intensive study was conducted on Clipperton Atoll (1,300 km SW of Acapulco), including macro-scale surface circulation, sea surface temperature (SST) climatology, geomorphology, coral community structure, zonation, and biogeography. Satellite-tracked drifter buoys from 1979 1993 demonstrated complex patterns of surface circulation with dominantly easterly flow (North Equatorial Counter Current, NECC), but also westerly currents (South Equatorial Current, SEC) that could transport propagules to Clipperton from both central and eastern Pacific regions. The northernmost latitude reached by the NECC is not influenced by El Niño-Southern Oscillation (ENSO) events, but easterly flow velocity evidently is accelerated at such times. Maximum NECC flow rates indicate that the eastern Pacific barrier can be bridged in 60 to 120 days. SST anomalies at Clipperton occur during ENSO events and were greater at Clipperton in 1987 than during 1982 1983. Shallow (15 18 m)and deep (50 58 m) terraces are present around most of Clipperton, probably representing Modern and late Pleistocene sea level stands. Although Clipperton is a well developed atoll with high coral cover, the reef-building fauna is depauperate, consisting of only 7 species of scleractinian corals belonging to the genera Pocillopora, Porites, Pavona and Leptoseris, and 1 species of hydrocoral in the genus Millepora. The identities of the one Pocilpopora species and one of the two Porites species are still unknown. Two of the remaining scleractinians ( Pavona minuta, Leptoseris scabra) and the hydrocoral ( Millepora exaesa), all formerly known from central and western Pacific localities, represent new eastern Pacific records. Scleractinian corals predominate (10 100% cover) over insular shelf depths of 8 to 60m, and crustose

  18. Circulation, eddies, oxygen and nutrient changes in the eastern tropical South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    R. Czeschel

    2014-09-01

    Full Text Available A large, subsurface oxygen deficiency zone is located in the eastern tropical South Pacific Ocean (ETSP. The large-scale circulation in the eastern equatorial Pacific and off Peru in November/December 2012 shows the influence of the equatorial current system, the eastern boundary currents, and the northern reaches of the subtropical gyre. In November 2012 the Equatorial Undercurrent is centered at 250 m depth, deeper than in earlier observations. In December 2012 the equatorial water is transported southeastward near the shelf in the Peru-Chile Undercurrent with a mean transport of 1.6 Sv. In the oxygen minimum zone (OMZ the flow is overlaid with strong eddy activity on the poleward side of the OMZ. Floats with parking depth at 400 m show fast westward flow in the mid-depth equatorial channel and sluggish flow in the OMZ. Floats with oxygen sensors clearly show the passage of eddies with oxygen anomalies. The long-term float observations in the upper ocean lead to a net community production estimate at about 18° S of up to 16.7 mmol C m−3 yr1 extrapolated to an annual rate and 7.7 mmol C m−3 yr−1 for the time period below the mixed layer. Oxygen differences between repeated ship sections are influenced by the Interdecadal Pacific Oscillation, by the phase of El Niño, by seasonal changes, and by eddies and hence have to be interpreted with care. At and south of the equator the decrease in oxygen in the upper ocean since 1976 is related to an increase in nitrate, phosphate, and in part in silicate.

  19. Water column biogeochemistry of oxygen minimum zones in the eastern tropical North Atlantic and eastern tropical South Pacific oceans

    Science.gov (United States)

    Löscher, Carolin R.; Bange, Hermann W.; Schmitz, Ruth A.; Callbeck, Cameron M.; Engel, Anja; Hauss, Helena; Kanzow, Torsten; Kiko, Rainer; Lavik, Gaute; Loginova, Alexandra; Melzner, Frank; Meyer, Judith; Neulinger, Sven C.; Pahlow, Markus; Riebesell, Ulf; Schunck, Harald; Thomsen, Sören; Wagner, Hannes

    2016-06-01

    Recent modeling results suggest that oceanic oxygen levels will decrease significantly over the next decades to centuries in response to climate change and altered ocean circulation. Hence, the future ocean may experience major shifts in nutrient cycling triggered by the expansion and intensification of tropical oxygen minimum zones (OMZs), which are connected to the most productive upwelling systems in the ocean. There are numerous feedbacks among oxygen concentrations, nutrient cycling and biological productivity; however, existing knowledge is insufficient to understand physical, chemical and biological interactions in order to adequately assess past and potential future changes. In the following, we summarize one decade of research performed in the framework of the Collaborative Research Center 754 (SFB754) focusing on climate-biogeochemistry interactions in tropical OMZs. We investigated the influence of low environmental oxygen conditions on biogeochemical cycles, organic matter formation and remineralization, greenhouse gas production and the ecology in OMZ regions of the eastern tropical South Pacific compared to the weaker OMZ of the eastern tropical North Atlantic. Based on our findings, a coupling of primary production and organic matter export via the nitrogen cycle is proposed, which may, however, be impacted by several additional factors, e.g., micronutrients, particles acting as microniches, vertical and horizontal transport of organic material and the role of zooplankton and viruses therein.

  20. The first report of a microdiverse anammox bacteria community in waters of Colombian Pacific, a transition area between prominent oxygen minimum zones of the eastern tropical Pacific.

    Science.gov (United States)

    Castro-González, M; Molina, V; Rodríguez-Rubio, E; Ulloa, O

    2014-12-01

    Anaerobic ammonium oxidizers contribute to the removal of fixed nitrogen in oxygen-deficient marine ecosystems such as oxygen minimum zones (OMZ). Here we surveyed for the first time the occurrence and diversity of anammox bacteria in the Colombian Pacific, a transition area between the prominent South and North Pacific OMZs. Anammox bacteria were detected in the coastal and oceanic areas of the Colombian Pacific in low oxygen (Pacific, Arabian Sea and Black Sea. Anammox bacteria-like sequences from the Colombian Pacific were grouped together with sequences retrieved from the distinct OMZ's marine subclusters (Peru, Northern Chile and Arabian Sea) within Candidatus ‘Scalindua spp’. Moreover, some anammox bacteria OTUs shared a low similarity with environmental phylotypes (86–94%). Our results indicated that a microdiverse anammox community inhabits the Colombian Pacific, generating new questions about the ecological and biogeochemical differences influencing its community structure.

  1. Oceanographic influences on seabirds and cetaceans of the eastern tropical Pacific: A review

    Science.gov (United States)

    Ballance, Lisa T.; Pitman, Robert L.; Fiedler, Paul C.

    2006-05-01

    This paper is part of a comprehensive review of the oceanography of the eastern tropical Pacific, the oceanic region centered on the eastern Pacific warm pool, but also including the equatorial cold tongue and equatorial current system, and summarizes what is known about oceanographic influences on seabirds and cetaceans there. The eastern tropical Pacific supports on the order of 50 species of seabirds and 30 species of cetaceans as regular residents; these include four endemic species, the world’s largest populations for several others, three endemic sub-species, and a multi-species community that is relatively unique to this ecosystem. Three of the meso-scale physical features of the region are particularly significant to seabirds and cetaceans: the Costa Rica Dome for blue whales and short-beaked common dolphins, the Equatorial Front for planktivorous seabirds, and the countercurrent thermocline ridge for flocking seabirds that associate with mixed-species schools of spotted and spinner dolphins and yellowfin tuna. A few qualitative studies of meso- to macro-scale distribution patterns have indicated that some seabirds and cetaceans have species-specific preferences for surface currents. More common are associations with distinct water masses; these relationships have been quantified for a number of species using several different analytical methods. The mechanisms underlying tropical species-habitat relationships are not well understood, in contrast to a number of higher-latitude systems. This may be due to the fact that physical variables have been used as proxies for prey abundance and distribution in species-habitat research in the eastern tropical Pacific. Though seasonal and interannual patterns tend to be complex, species-habitat relationships appear to remain relatively stable over time, and distribution patterns co-vary with patterns of preferred habitat for a number of species. The interactions between seasonal and interannual variation in

  2. Feeding grounds of the eastern South Pacific humpback whale population include the South Orkney Islands

    OpenAIRE

    Dalla Rosa, Luciano; Félix, Fernando; Stevick, Peter T.; Secchi,Eduardo R; Allen, Judith M; Chater, Kim; Martin, Anthony R.; Basso, Manuela

    2012-01-01

    This paper reports on two photo-identified humpback whales (Megaptera novaeangliae) that were sighted in different years in the proximity of the South Orkney Islands, at the boundary between the Scotia and Weddell seas (60o54.5’S – 46o40.4’W and 60o42.6’S – 45o33’W). One of the whales had been previously sighted off Ecuador, a breeding ground for the eastern South Pacific population. The other whale was subsequently resighted in Bransfield Strait, off the western Antarctic Peninsula, a well-d...

  3. On the Cause of Eastern Equatorial Pacific Ocean T-S Variations Associated with El Nino

    Science.gov (United States)

    Wang, Ou; Fukumori, Ichiro; Lee, Tong; Cheng, Benny

    2004-01-01

    The nature of observed variations in temperature-salinity (T-S) relationship between El Nino and non-El Nino years in the pycnocline of the eastern equatorial Pacific Ocean (NINO3 region, 5(deg)S-5(deg)N, 150(deg)W-90(deg)W) is investigated using an ocean general circulation model. The origin of the subject water mass is identified using the adjoint of a simulated passive tracer. The higher salinity during El Nino is attributed to larger convergence of saltier water from the Southern Hemisphere and smaller convergence of fresher water from the Northern Hemisphere.

  4. Fragile Reefs of the Eastern Pacific: Does low Cementation Provide a Model for Reefs in a High CO2 World?

    Science.gov (United States)

    Manzello, D.; Kleypas, J.; Eakin, M.; Budd, D.

    2007-05-01

    Around the world, reefs will experience high pCO2, low pH, low carbonate concentrations, and low aragonite saturation state as atmospheric CO2 rises. Ocean carbon chemistry measurements show that eastern Pacific waters already exist at high pCO2 and low carbonate concentrations due to natural upwelling in the region. Because of the upwelling, this region may serve as a model for coral reef development under enhanced atmospheric CO2 and oceanic pCO2; that is, low coral growth, low secondary cementation, and high physical, chemical, and biological erosion. Reefs in the eastern Pacific Ocean are characterized by low biological diversity and relatively small size. Both past coring and recent analysis reveal that, while many reefs in the eastern Pacific are several thousand years old, they are fragile and lack significant cementation, even in the innermost, oldest structures. They are also extremely porous with high water throughflow. Without secondary cementation, branching coral frameworks are held together only by organically produced calcium carbonate (e.g. coralline algae), sponges, and other reef infauna, and contain a high proportion of loose sediments. The result is reef frameworks that are more susceptible to destruction from mechanical or biological erosion. The poorly cemented nature of eastern Pacific reefs is thus hypothesized to have been a factor in the severe bioerosion that occurred on these reefs after past bleaching events (1982-3, 1997-8). We will present data that indicate low rates of cementation and high rates of erosion on eastern Pacific coral reefs and will compare current carbonate chemistry in the eastern Pacific to model predictions of what reefs around the globe may experience in coming decades.

  5. Siderophore-based microbial adaptations to iron scarcity across the eastern Pacific Ocean

    Science.gov (United States)

    Boiteau, Rene M.; Mende, Daniel R.; Hawco, Nicholas J.; McIlvin, Matthew R.; Fitzsimmons, Jessica N.; Saito, Mak A.; Sedwick, Peter N.; DeLong, Edward F.; Repeta, Daniel J.

    2016-12-01

    Nearly all iron dissolved in the ocean is complexed by strong organic ligands of unknown composition. The effect of ligand composition on microbial iron acquisition is poorly understood, but amendment experiments using model ligands show they can facilitate or impede iron uptake depending on their identity. Here we show that siderophores, organic compounds synthesized by microbes to facilitate iron uptake, are a dynamic component of the marine ligand pool in the eastern tropical Pacific Ocean. Siderophore concentrations in iron-deficient waters averaged 9 pM, up to fivefold higher than in iron-rich coastal and nutrient-depleted oligotrophic waters, and were dominated by amphibactins, amphiphilic siderophores with cell membrane affinity. Phylogenetic analysis of amphibactin biosynthetic genes suggests that the ability to produce amphibactins has transferred horizontally across multiple Gammaproteobacteria, potentially driven by pressures to compete for iron. In coastal and oligotrophic regions of the eastern Pacific Ocean, amphibactins were replaced with lower concentrations (1–2 pM) of hydrophilic ferrioxamine siderophores. Our results suggest that organic ligand composition changes across the surface ocean in response to environmental pressures. Hydrophilic siderophores are predominantly found across regions of the ocean where iron is not expected to be the limiting nutrient for the microbial community at large. However, in regions with intense competition for iron, some microbes optimize iron acquisition by producing siderophores that minimize diffusive losses to the environment. These siderophores affect iron bioavailability and thus may be an important component of the marine iron cycle.

  6. Homoplasious colony morphology and mito-nuclear phylogenetic discordance among Eastern Pacific octocorals.

    Science.gov (United States)

    Ament-Velásquez, Sandra L; Breedy, Odalisca; Cortés, Jorge; Guzman, Hector M; Wörheide, Gert; Vargas, Sergio

    2016-05-01

    Octocorals are a diverse and ecologically important group of cnidarians. However, the phylogenetic relationships of many octocoral groups are not well understood and are based mostly on mitochondrial sequence data. In addition, the discovery and description of new gorgonian species displaying unusual or intermediate morphologies and uncertain phylogenetic affinities further complicates the study of octocoral systematics and raises questions about the role played by processes such as plasticity, crypsis, and convergence in the evolution of this group of organisms. Here, we use nuclear (i.e. 28S rDNA) and mitochondrial (mtMutS) markers and a sample of Eastern Pacific gorgonians thought to be remarkable from a morphological point of view to shed light on the morphological diversification among these organisms. Our study reveals the loss of the anastomosed colony morphology in two unrelated lineages of the seafan genus Pacifigorgia and offers strong evidence for the independent evolution of a whip-like morphology in two lineages of Eastern Pacific Leptogorgia. Additionally, our data revealed one instance of mito-nuclear discordance in the genera Leptogorgia and Eugorgia, which may be the results of incomplete lineage sorting or ancient hybridization-introgression events. Our study stresses the importance of comprehensive taxonomic sampling and the use of independent sources of evidence to address the phylogenetic relationships and clarifying the evolution of octocorals.

  7. Characterization of mesoscale convective systems over the eastern Pacific during boreal summer

    Science.gov (United States)

    Berthet, Sarah; Rouquié, Bastien; Roca, Rémy

    2015-04-01

    The eastern Pacific Ocean is one of the most active tropical disturbances formation regions on earth. This preliminary study is part of a broader project that aims to investigate how mesoscale convective systems (MCS) may be related to these synoptic disturbances with emphasis on local initiation of tropical depressions. As a first step, the main characteristics of the MCS over the eastern Pacific are documented with the help of the recently developed TOOCAN tracking algorithm (Fiolleau and Roca, 2013) applied to the infrared satellite imagery data from GOES-W and -E for the period JJAS 2012-2014. More specifically, the spatial distribution of the MCS population, the statistics of their spatial extensions and durations, as well as their trajectories and propagation speeds are summarized. In addition the environment of the MCS will be investigated using various Global Precipitation Mission datasets and the Megha-Tropiques/SAPHIR humidity microwave sounder derived products. Reference: Fiolleau T. and R. Roca, (2013), An Algorithm For The Detection And Tracking Of Tropical Mesoscale Convective Systems Using Infrared Images From Geostationary Satellite, Transactions on Geoscience and Remote Sensing, doi: 10.1109/TGRS.2012.2227762.

  8. Temporal separation of two fin whale call types across the eastern North Pacific.

    Science.gov (United States)

    Sirović, Ana; Williams, Lauren N; Kerosky, Sara M; Wiggins, Sean M; Hildebrand, John A

    2013-01-01

    Fin whales (Balaenoptera physalus) produce a variety of low-frequency, short-duration, frequency-modulated calls. The differences in temporal patterns between two fin whale call types are described from long-term passive acoustic data collected intermittently between 2005 and 2011 at three locations across the eastern North Pacific: the Bering Sea, off Southern California, and in Canal de Ballenas in the northern Gulf of California. Fin whale calls were detected at all sites year-round, during all periods with recordings. At all three locations, 40-Hz calls peaked in June, preceding a peak in 20-Hz calls by 3-5 months. Monitoring both call types may provide a more accurate insight into the seasonal presence of fin whales across the eastern North Pacific than can be obtained from a single call type. The 40-Hz call may be associated with a foraging function, and temporal separation between 40- and 20-Hz calls may indicate the separation between predominately feeding behavior and other social interactions.

  9. Impacts of an Improved Low-Level Cloud Scheme on the Eastern Pacific ITCZ-Cold Tongue Complex

    Institute of Scientific and Technical Information of China (English)

    DM Fushan; YU Rucong; ZHANG Xuehong; YU Yongqiang; LI Jianglong

    2005-01-01

    A statistically-based low-level cloud parameterization scheme is introduced, modified, and applied in the Flexible coupled General Circulation Model (FGCM-0). It is found that the low-level cloud scheme makes improved simulations of low-level cloud fractions and net surface shortwave radiation fluxes in the subtropical eastern oceans off western coasts in the model. Accompanying the improvement in the net surface shortwave radiation fluxes, the simulated distribution of SSTs is more reasonably asymmetrical about the equator in the tropical eastern Pacific, which suppresses, to some extent, the development of the double ITCZ in the model. Warm SST biases in the ITCZ north of the equator are more realistically reduced, too. But the equatorial cold tongue is strengthened and extends further westward, which reduces the precipitation rate in the western equatorial Pacific but increases it in the ITCZ north of the equator in the far eastern Pacific. It is demonstrated that the low-level cloud-radiation feedback would enhance the cooperative feedback between the equatorial cold tongue and the ITCZ. Based on surface layer heat budget analyses, it is demonstrated that the reduction of SSTs is attributed to both the thermodynamic cooling process modified by the increase of cloud fractions and the oceanic dynamical cooling processes associated with the strengthened surface wind in the eastern equatorial Pacific, but it is mainly attributed to oceanic dynamical cooling processes associated with the strengthening of surface wind in the central and western equatorial Pacific.

  10. Description of two new associated infaunal decapod crustaceans (Axianassidae and Alpheidae from the tropical eastern Pacific

    Directory of Open Access Journals (Sweden)

    Arthur Anker

    2015-08-01

    Full Text Available Two new species of infaunal decapod crustaceans are described based on material collected in Bahía Málaga, Pacific coast of Colombia, in 2009. The mud-shrimp Axianassa darrylfelderi sp. nov. (Axianassidae appears to be most closely related to A. australis Rodrigues & Shimizu, 1992, A. canalis Kensley & Heard, 1990, and A. jamaicensis Kensley & Heard, 1990. The new species may be distinguished from each of them by a combination of morphological features, mainly on the uropodal exopod, antennal acicle, third maxilliped and first pleonite. The shrimp Leptalpheus canterakintzi sp. nov. (Alpheidae, associated with burrows of A. darrylfelderi sp. nov., undoubtedly represents the eastern Pacific sister species of the western Atlantic L. axianassae Dworschak & Coelho, 1999, which lives exclusively in burrows of A. australis. The two species are reliably distinguishable only by the proportions of the merus and propodus of the third pereiopod. Leptalpheus azuero Anker, 2011, previously known only from the Pacific coast of Panama, is reported for the first time from Bahía Málaga, Colombia.

  11. Population genetics of an ecosystem-defining reef coral Pocillopora damicornis in the Tropical Eastern Pacific.

    Directory of Open Access Journals (Sweden)

    David J Combosch

    Full Text Available BACKGROUND: Coral reefs in the Tropical Eastern Pacific (TEP are amongst the most peripheral and geographically isolated in the world. This isolation has shaped the biology of TEP organisms and lead to the formation of numerous endemic species. For example, the coral Pocillopora damicornis is a minor reef-builder elsewhere in the Indo-West Pacific, but is the dominant reef-building coral in the TEP, where it forms large, mono-specific stands, covering many hectares of reef. Moreover, TEP P. damicornis reproduces by broadcast spawning, while it broods mostly parthenogenetic larvae throughout the rest of the Indo-West Pacific. Population genetic surveys for P. damicornis from across its Indo-Pacific range indicate that gene flow (i.e. larval dispersal is generally limited over hundreds of kilometers or less. Little is known about the population genetic structure and the dispersal potential of P. damicornis in the TEP. METHODOLOGY: Using multilocus microsatellite data, we analyzed the population structure of TEP P. damicornis among and within nine reefs and test for significant genetic structure across three geographically and ecologically distinct regions in Panama. PRINCIPAL FINDINGS/CONCLUSIONS: We detected significant levels of population genetic structure (global R(ST = 0.162, indicating restricted gene flow (i.e. larvae dispersal, both among the three regions (R(RT = 0.081 as well as within regions (R(SR = 0.089. Limited gene flow across a distinct environmental cline, like the regional upwelling gradient in Panama, indicates a significant potential for differential adaptation and population differentiation. Individual reefs were characterized by unexpectedly high genet diversity (avg. 94%, relatively high inbreeding coefficients (global F(IS = 0.183, and localized spatial genetic structure among individuals (i.e. unique genets over 10 m intervals. These findings suggest that gene flow is limited in TEP P. damicornis

  12. Size-fractionated diversity of eukaryotic microbial communities in the Eastern Tropical North Pacific oxygen minimum zone.

    Science.gov (United States)

    Duret, Manon T; Pachiadaki, Maria G; Stewart, Frank J; Sarode, Neha; Christaki, Urania; Monchy, Sébastien; Srivastava, Ankita; Edgcomb, Virginia P

    2015-05-01

    Oxygen minimum zones (OMZs) caused by water column stratification appear to expand in parts of the world's ocean, with consequences for marine biogeochemical cycles. OMZ formation is often fueled by high surface primary production, and sinking organic particles can be hotspots of interactions and activity within microbial communities. This study investigated the diversity of OMZ protist communities in two biomass size fractions (>30 and 30-1.6 μm filters) from the world's largest permanent OMZ in the Eastern Tropical North Pacific. Diversity was quantified via Illumina MiSeq sequencing of V4 region of 18S SSU rRNA genes in samples spanning oxygen gradients at two stations. Alveolata and Rhizaria dominated the two size fractions at both sites along the oxygen gradient. Community composition at finer taxonomic levels was partially shaped by oxygen concentration, as communities associated with versus anoxic waters shared only ∼32% of operational taxonomic unit (OTU) (97% sequence identity) composition. Overall, only 9.7% of total OTUs were recovered at both stations and under all oxygen conditions sampled, implying structuring of the eukaryotic community in this area. Size-fractionated communities exhibited different taxonomical features (e.g. Syndiniales Group I in the 1.6-30 μm fraction) that could be explained by the microniches created on the surface-originated sinking particles.

  13. Spatial and temporal variability in nutrients and carbon uptake during 2004 and 2005 in the eastern equatorial Pacific Ocean

    DEFF Research Database (Denmark)

    Palacz, A. P.; Chai, F.

    2012-01-01

    The eastern equatorial Pacific plays a great role in the global carbon budget due to its enhanced biological productivity linked to the equatorial upwelling. However, as confirmed by the Equatorial Biocomplexity cruises in 2004 and 2005, nutrient upwelling supply varies strongly, partly due to th...

  14. Whales, Dolphins, and Porpoises of the Eastern North Pacific and Adjacent Arctic Waters: A Guide to Their Identification.

    Science.gov (United States)

    Leatherwood, Stephen; And Others

    This field guide is designed to permit observers to identify the cetaceans (whales, dolphins, and porpoises) they see in the waters of the eastern North Pacific, including the Gulf of California, Hawaii, and the western Arctic of North America. The animals described are grouped not by scientific relationships but by similarities in appearance in…

  15. Whales, Dolphins, and Porpoises of the Eastern North Pacific and Adjacent Arctic Waters: A Guide to Their Identification.

    Science.gov (United States)

    Leatherwood, Stephen; And Others

    This field guide is designed to permit observers to identify the cetaceans (whales, dolphins, and porpoises) they see in the waters of the eastern North Pacific, including the Gulf of California, Hawaii, and the western Arctic of North America. The animals described are grouped not by scientific relationships but by similarities in appearance in…

  16. NUMERICAL MODELING STUDY OF EFFECTS OF EASTERN PACIFIC WARM POOL ON ENSO

    Institute of Scientific and Technical Information of China (English)

    YUE Cai-jun; LU Wei-song; Xiaofan LI

    2010-01-01

    In this study,sensitivity experiments were conducted with the Zebiak-Cane ocean-atmosphere coupled model forced by the wind stress anomaly from the U.S.National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data to study the impacts of eastern Pacific warm pool on the formation and development of ENSO events.The effects of climatological mean sea surface temperature of the warm pool on forecast skill during the ENSO events of 1982-1999 are more considerable that those of climatological mean meridional winds and ocean currents.The forecast skill for the 1997/1998 E1 Ni(n)o event is characterized by sensitivity to climatological mean sea surface temperature and anomalies of northerly winds and currents.The forecast skill is found insensitive to climatological mean northerly meridional winds and currents.

  17. Plastic ingestion in marine-associated bird species from the eastern North Pacific.

    Science.gov (United States)

    Avery-Gomm, S; Provencher, J F; Morgan, K H; Bertram, D F

    2013-07-15

    In addition to monitoring trends in plastic pollution, multi-species surveys are needed to fully understand the pervasiveness of plastic ingestion. We examined the stomach contents of 20 bird species collected from the coastal waters of the eastern North Pacific, a region known to have high levels of plastic pollution. We observed no evidence of plastic ingestion in Rhinoceros Auklet, Marbled Murrelet, Ancient Murrelet or Pigeon Guillemot, and low levels in Common Murre (2.7% incidence rate). Small sample sizes limit our ability to draw conclusions about population level trends for the remaining fifteen species, though evidence of plastic ingestion was found in Glaucous-Winged Gull and Sooty Shearwater. Documenting levels of plastic ingestion in a wide array of species is necessary to gain a comprehensive understanding about the impacts of plastic pollution. We propose that those working with bird carcasses follow standard protocols to assess the levels of plastic ingestion whenever possible.

  18. Response of North Pacific eastern subtropical mode water to greenhouse gas versus aerosol forcing

    Science.gov (United States)

    Li, Xiang; Luo, Yiyong

    2016-04-01

    Mode water is a distinct water mass characterized by a near vertical homogeneous layer or low potential vorticity, and is considered essential for understanding ocean climate variability. Based on the output of GFDL CM3, this study investigates the response of eastern subtropical mode water (ESTMW) in the North Pacific to two different single forcings: greenhouse gases (GHGs) and aerosol. Under GHG forcing, ESTMW is produced on lighter isopycnal surfaces and is decreased in volume. Under aerosol forcing, in sharp contrast, it is produced on denser isopycnal surfaces and is increased in volume. The main reason for the opposite response is because surface ocean-to-atmosphere latent heat flux change over the ESTMW formation region shoals the mixed layer and thus weakens the lateral induction under GHG forcing, but deepens the mixed layer and thus strengthens the lateral induction under aerosol forcing. In addition, local wind changes are also favorable to the opposite response of ESTMW production to GHG versus aerosol.

  19. Non-destructive γ spectrum analysis of polymetallic nodules from the eastern Pacific

    Institute of Scientific and Technical Information of China (English)

    刘广山; 黄奕普; 蔡毅华; 陈敏

    2002-01-01

    -- Non-destructive γ spectrum analyses of 20 polymetallic nodules from the eastern Pacific were carried out. Numerous nuclides, such as 238 U, 230 Th, 226 Ra, 210 Pb, 228 Ra, 228 Th, 235 U, 227 Ac ( or 231pa) and 40K were detected. The count rates of the nuclides in the top or bottom side of nodules facing detector were measured and the ratio R of the count rates of nuclides in the top and the bottom sides was obtained. From counts and ratios, some useful information relating to the growth and movement of the nodules, the source of nuclide and relationship between those and environment can be gotten. A new method for clear distinction between the top and bottom sides of the nodule based on the R value of 226Ra or 210pb was developed. In addition, one can infer the turnover of nodules according to the R value of 230Th.

  20. Eccentricity pacing of eastern equatorial Pacific carbonate dissolution cycles during the Miocene Climatic Optimum

    Science.gov (United States)

    Kochhann, Karlos G. D.; Holbourn, Ann; Kuhnt, Wolfgang; Channell, James E. T.; Lyle, Mitch; Shackford, Julia K.; Wilkens, Roy H.; Andersen, Nils

    2016-09-01

    The Miocene Climatic Optimum (MCO; ~16.9 to 14.7 Ma) provides an outstanding opportunity to investigate climate-carbon cycle dynamics during a geologically recent interval of global warmth. We present benthic stable oxygen (δ18O) and carbon (δ13C) isotope records (5-12 kyr time resolution) spanning the late early to middle Miocene interval (18 to 13 Ma) at Integrated Ocean Drilling Program (IODP) Site U1335 (eastern equatorial Pacific Ocean). The U1335 stable isotope series track the onset and development of the MCO as well as the transitional climatic phase culminating with global cooling and expansion of the East Antarctic Ice Sheet at ~13.8 Ma. We integrate these new data with published stable isotope, geomagnetic polarity, and X-ray fluorescence (XRF) scanner-derived carbonate records from IODP Sites U1335, U1336, U1337, and U1338 on a consistent, astronomically tuned timescale. Benthic isotope and XRF scanner-derived CaCO3 records depict prominent 100 kyr variability with 400 kyr cyclicity additionally imprinted on δ13C and CaCO3 records, pointing to a tight coupling between the marine carbon cycle and climate variations. Our intersite comparison further indicates that the lysocline behaved in highly dynamic manner throughout the MCO, with >75% carbonate loss occurring at paleodepths ranging from ~3.4 to ~4 km in the eastern equatorial Pacific Ocean. Carbonate dissolution maxima coincide with warm phases (δ18O minima) and δ13C decreases, implying that climate-carbon cycle feedbacks fundamentally differed from the late Pleistocene glacial-interglacial pattern, where dissolution maxima correspond to δ13C maxima and δ18O minima. Carbonate dissolution cycles during the MCO were, thus, more similar to Paleogene hyperthermal patterns.

  1. Simulating Tropical Instability Waves in the Equatorial Eastern Pacific with a Coupled General Circulation Model

    Institute of Scientific and Technical Information of China (English)

    CHEN Xianyan; Masahide KIMOTO

    2009-01-01

    Satellite observations of SSTs have revealed the existence of unstable waves in the equatorial eastern Pacific and Atlantic oceans. These waves have a 20-40-day periodicity with westward phase speeds of 0.4-0.6 m s-1 and wavelengths of 1000-2000 km during boreal summer and fall.They are generally called tropical instability waves (TIWs).This study investigates TIWs simulated by a high-resolution coupled atmosphere-ocean general circulation model (AOGCM).The horizontal resolution of the model is 120 km in the atmosphere,and 30 km longitude by 20 km latitude in the ocean.Model simulations show good agreement with the observed main features associated with TIWs.The results of energetics analysis reveal that barotropic energy conversion is responsible for providing the main energy source for TIWs by extracting energy from the meridional shear of the climatological-mean equatorial currents in the mixed layer.This deeper and northward-extended wave activity appears to gain its energy through baroclinic conversion via buoyancy work,which further contributes to the asymmetric distribution of TIWs.It is estimated that the strong cooling effect induced by equatorial upwelling is partially (~30%-40%)offset by the equatorward heat flux due to TIWs in the eastern tropical Pacific during the seasons when TIWs are active.The atmospheric mixed layer just above the sea surface responds to the waves with enhanced or reduced vertical mixing.Furthermore,the changes in turbulent mixing feed back to sea surface evaporation,favoring the westward propagation of TIWs.The atmosphere to the south of the Equator also responds to TIWs in a similar way,although TIWs are much weaker south of the Equator.

  2. Blue whale population structure along the eastern South Pacific Ocean: evidence of more than one population.

    Science.gov (United States)

    Torres-Florez, J P; Hucke-Gaete, R; LeDuc, R; Lang, A; Taylor, B; Pimper, L E; Bedriñana-Romano, L; Rosenbaum, H C; Figueroa, C C

    2014-12-01

    Blue whales (Balaenoptera musculus) were among the most intensively exploited species of whales in the world. As a consequence of this intense exploitation, blue whale sightings off the coast of Chile were uncommon by the end of the 20th century. In 2004, a feeding and nursing ground was reported in southern Chile (SCh). With the aim to investigate the genetic identity and relationship of these Chilean blue whales to those in other Southern Hemisphere areas, 60 biopsy samples were collected from blue whales in SCh between 2003 and 2009. These samples were genotyped at seven microsatellite loci and the mitochondrial control region was sequenced, allowing us to identify 52 individuals. To investigate the genetic identity of this suspected remnant population, we compared these 52 individuals to blue whales from Antarctica (ANT, n = 96), Northern Chile (NCh, n = 19) and the eastern tropical Pacific (ETP, n = 31). No significant differentiation in haplotype frequencies (mtDNA) or among genotypes (nDNA) was found between SCh, NCh and ETP, while significant differences were found between those three areas and Antarctica for both the mitochondrial and microsatellite analyses. Our results suggest at least two breeding population units or subspecies exist, which is also supported by other lines of evidence such as morphometrics and acoustics. The lack of differences detected between SCh/NCh/ETP areas supports the hypothesis that eastern South Pacific blue whales are using the ETP area as a possible breeding area. Considering the small population sizes previously reported for the SCh area, additional conservation measures and monitoring of this population should be developed and prioritized.

  3. THE FUTURE OF THE EASTERN PARTNERSHIP: “BUILDING A SHARED EUROPEAN HOME”

    Directory of Open Access Journals (Sweden)

    Maria SARAKUTSA

    2016-12-01

    Full Text Available The year 2014 became a turning point in the history of the EU Eastern Partnership (EaP, marked by the signing of the Association Agreements with three EaP states and a conflict in Ukraine. In view of the above, current research focuses on assessing the feasibility of scenarios of the EaP future, discussed in scholarship, based on the assessment of the EU’s foreign policy successes and challenges in Eastern Neighbourhood. EU’s internal issues, re-emerging geostrategic threats and domestic challenges in the EaP states are analyzed. The considered scenarios include the EU’s acceptance of the status quo in the region, taking a stronger stance on the integration of Ukraine, Moldova, and Georgia, as well as building “a shared European home” by promoting a rapprochement with Russia. The single scenario for the EU’s policy in the EaP states is suggested, and the reason why the EU will try to “build a shared European home” is explained.

  4. The invasive snowflake coral (Carijoa riisei in the Tropical Eastern Pacific, Colombia

    Directory of Open Access Journals (Sweden)

    Juan Armando Sánchez

    2014-02-01

    Full Text Available Carijoa riisei (Octocorallia: Cnidaria, a western Atlantic species, has been reported in the Pacific as an invasive species for nearly forty years. C. riisei has been recently observed overgrowing native octocorals at several rocky-coral littorals in the Colombian Tropical Eastern Pacific-(TEP. C. riisei has inhabited these reefs for at least 15 years but the aggressive overgrowth on other octocorals have been noted until recently. Here, we surveyed for the first time the distribution and inter-specific aggression by C. riisei in both coastal and oceanic areas colonized in the Colombian TEP (Malpelo, Gorgona and Cabo Corrientes, including preliminary multiyear surveys during 2007-2013. We observed community-wide octocoral mortalities (including local extinction of some Muricea spp. and a steady occurrence of competing and overgrowing Pacifigorgia seafans and Leptogorgia seawhips. In Gorgona Island, at two different sites, over 87% (n=77 tagged colonies of octocorals (Pacifigorgia spp. and Leptogorgia alba died as a result of C. riisei interaction and/or overgrowth between 2011 and 2013. C. riisei overgrows octocorals with an estimate at linear growth rate of about 1cm m-1. The aggressive overgrowth of this species in TEP deserves more attention and regular monitoring programs. Rev. Biol. Trop. 62 (Suppl. 1: 199-207. Epub 2014 February 01.

  5. Hawksbill turtle terra incognita: conservation genetics of eastern Pacific rookeries.

    Science.gov (United States)

    Gaos, Alexander R; Lewison, Rebecca L; Liles, Michael J; Gadea, Velkiss; Altamirano, Eduardo; Henríquez, Ana V; Torres, Perla; Urteaga, José; Vallejo, Felipe; Baquero, Andres; LeMarie, Carolina; Muñoz, Juan Pablo; Chaves, Jaime A; Hart, Catherine E; Peña de Niz, Alejandro; Chácon, Didiher; Fonseca, Luis; Otterstrom, Sarah; Yañez, Ingrid L; LaCasella, Erin L; Frey, Amy; Jensen, Michael P; Dutton, Peter H

    2016-02-01

    Prior to 2008 and the discovery of several important hawksbill turtle (Eretmochelys imbricata) nesting colonies in the EP (Eastern Pacific), the species was considered virtually absent from the region. Research since that time has yielded new insights into EP hawksbills, salient among them being the use of mangrove estuaries for nesting. These recent revelations have raised interest in the genetic characterization of hawksbills in the EP, studies of which have remained lacking to date. Between 2008 and 2014, we collected tissue samples from 269 nesting hawksbills at nine rookeries across the EP and used mitochondrial DNA sequences (766 bp) to generate the first genetic characterization of rookeries in the region. Our results inform genetic diversity, population differentiation, and phylogeography of the species. Hawksbills in the EP demonstrate low genetic diversity: We identified a total of only seven haplotypes across the region, including five new and two previously identified nesting haplotypes (pooled frequencies of 58.4% and 41.6%, respectively), the former only evident in Central American rookeries. Despite low genetic diversity, we found strong stock structure between the four principal rookeries, suggesting the existence of multiple populations and warranting their recognition as distinct management units. Furthermore, haplotypes EiIP106 and EiIP108 are unique to hawksbills that nest in mangrove estuaries, a behavior found only in hawksbills along Pacific Central America. The detected genetic differentiation supports the existence of a novel mangrove estuary "reproductive ecotype" that may warrant additional conservation attention. From a phylogeographic perspective, our research indicates hawksbills colonized the EP via the Indo-Pacific, and do not represent relict populations isolated from the Atlantic by the rising of the Panama Isthmus. Low overall genetic diversity in the EP is likely the combined result of few rookeries, extremely small

  6. Constraining Cretaceous subduction polarity in eastern Pacific from seismic tomography and geodynamic modeling

    Science.gov (United States)

    Liu, Lijun

    2014-11-01

    Interpretation of recent mantle seismic images below the America ignited a debate on the Cretaceous subduction polarity in the eastern Pacific Ocean. The traditional view is that the massive vertical slab wall under eastern North America resulted from an eastward Farallon subduction. An alternative interpretation attributes this prominent seismic structure to a westward subduction of the North American Plate against a stationary intraoceanic trench. Here I design quantitative subduction models to test these two scenarios, using their implied plate kinematics as velocity boundary conditions. Modeling results suggest that the westward subduction scenario could not produce enough slab volume as seismic images reveal, as is due to the overall slow subduction rate (~2.5 cm/yr). The results favor the continuous eastward Farallon subduction scenario, which, with an average convergence rate of >10 cm/yr prior to the Eocene, can properly generate both the volume and the geometry of the imaged lower mantle slab pile. The eastward subduction model is also consistent with most Cretaceous geological records along the west coast of North America.

  7. Biogeochemical characteristics of a long-lived anticyclonic eddy in the eastern South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    M. Cornejo

    2015-09-01

    Full Text Available Eastern boundary upwelling systems are characterized by high productivity that often leads to subsurface hypoxia on the shelf. Mesoscale eddies are important, frequent, and persistent features of circulation in these regions, transporting physical, chemical and biological properties from shelves to the open ocean. In austral fall of 2011, during the Tara Oceans expedition, a subsurface layer (200–400 m in which the concentration of oxygen was very low (−1 of O2 was observed in the eastern South Pacific, ~ 900 km offshore (30° S, 81° W. Satellite altimetry combined with CTD observations associated the local oxygen anomaly with an intrathermocline, anticyclonic, mesoscale eddy with a diameter of about 150 km. The eddy contained Equatorial Subsurface Water (ESSW that at this latitude is normally restricted near the coast. Undersaturation (44 % of nitrous oxide (N2O and nitrite accumulation (> 0.5 μM gave evidence for denitrification in this water mass. Based on satellite altimetry, we tracked the eddy back to its region of formation on the coast of central Chile (36.1° S, 74.6° W. We estimate that the eddy formed in April 2010. Field studies conducted on the Chilean shelf in June 2010 provided approximate information on initial O2 and N2O concentrations of "source water" in the region at the time of eddy formation. Concentrations of both O2 and N2O in the oxygen minimum zone (OMZ of the offshore eddy were lower than its surroundings or "source water" on the shelf, suggesting that these chemical species were consumed as the eddy moved offshore. Estimates of apparent oxygen utilization rates at the OMZ of the eddy ranged from 0.29 to 44 nmol L−1 d−1 and the rate of N2O consumption was 3.92 nmol L−1 d−1. Our results show that mesoscale eddies in the ESP not only transport physical properties of the ESSW from the coast to the ocean interior, but also export and transform biogeochemical properties, creating suboxic environments in the

  8. Genetic variation in blue whales in the eastern pacific: implication for taxonomy and use of common wintering grounds.

    Science.gov (United States)

    Leduc, R G; Archer, F I; Lang, A R; Martien, K K; Hancock-Hanser, B; Torres-Florez, J P; Hucke-Gaete, R; Rosenbaum, H C; van Waerebeek, K; Brownell, R L; Taylor, B L

    2017-02-01

    Many aspects of blue whale biology are poorly understood. Some of the gaps in our knowledge, such as those regarding their basic taxonomy and seasonal movements, directly affect our ability to monitor and manage blue whale populations. As a step towards filling in some of these gaps, microsatellite and mtDNA sequence analyses were conducted on blue whale samples from the Southern Hemisphere, the eastern tropical Pacific (ETP) and the northeast Pacific. The results indicate that the ETP is differentially used by blue whales from the northern and southern eastern Pacific, with the former showing stronger affinity to the region off Central America known as the Costa Rican Dome, and the latter favouring the waters of Peru and Ecuador. Although the pattern of genetic variation throughout the Southern Hemisphere is compatible with the recently proposed subspecies status of Chilean blue whales, some discrepancies remain between catch lengths and lengths from aerial photography, and not all blue whales in Chilean waters can be assumed to be of this type. Also, the range of the proposed Chilean subspecies, which extends to the Galapagos region of the ETP, at least seasonally, perhaps should include the Costa Rican Dome and the eastern North Pacific as well. © 2016 John Wiley & Sons Ltd.

  9. Modeling the inorganic bromine partitioning in the tropical tropopause layer over the eastern and western Pacific Ocean

    Directory of Open Access Journals (Sweden)

    M. A. Navarro

    2017-08-01

    Full Text Available The stratospheric inorganic bromine (Bry burden arising from the degradation of brominated very short-lived organic substances (VSLorg and its partitioning between reactive and reservoir species is needed for a comprehensive assessment of the ozone depletion potential of brominated trace gases. Here we present modeled inorganic bromine abundances over the Pacific tropical tropopause based on aircraft observations of VSLorg from two campaigns of the Airborne Tropical TRopopause EXperiment (ATTREX 2013, carried out over the eastern Pacific, and ATTREX 2014, carried out over the western Pacific and chemistry-climate simulations (along ATTREX flight tracks using the specific meteorology prevailing. Using the Community Atmosphere Model with Chemistry (CAM-Chem we model that BrO and Br are the daytime dominant species. Integrated across all ATTREX flights, BrO represents ∼ 43 and 48 % of daytime Bry abundance at 17 km over the western and eastern Pacific, respectively. The results also show zones where Br / BrO > 1 depending on the solar zenith angle (SZA, ozone concentration, and temperature. On the other hand, BrCl and BrONO2 were found to be the dominant nighttime species with ∼  61 and 56 % of abundance at 17 km over the western and eastern Pacific, respectively. The western-to-eastern differences in the partitioning of inorganic bromine are explained by different abundances of ozone (O3, nitrogen dioxide (NO2, total inorganic chlorine (Cly, and the efficiency of heterogeneous reactions of bromine reservoirs (mostly BrONO2 and HBr occurring on ice crystals.

  10. Modeling the inorganic bromine partitioning in the tropical tropopause layer over the eastern and western Pacific Ocean

    Science.gov (United States)

    Navarro, Maria A.; Saiz-Lopez, Alfonso; Cuevas, Carlos A.; Fernandez, Rafael P.; Atlas, Elliot; Rodriguez-Lloveras, Xavier; Kinnison, Douglas; Lamarque, Jean-Francois; Tilmes, Simone; Thornberry, Troy; Rollins, Andrew; Elkins, James W.; Hintsa, Eric J.; Moore, Fred L.

    2017-08-01

    The stratospheric inorganic bromine (Bry) burden arising from the degradation of brominated very short-lived organic substances (VSLorg) and its partitioning between reactive and reservoir species is needed for a comprehensive assessment of the ozone depletion potential of brominated trace gases. Here we present modeled inorganic bromine abundances over the Pacific tropical tropopause based on aircraft observations of VSLorg from two campaigns of the Airborne Tropical TRopopause EXperiment (ATTREX 2013, carried out over the eastern Pacific, and ATTREX 2014, carried out over the western Pacific) and chemistry-climate simulations (along ATTREX flight tracks) using the specific meteorology prevailing. Using the Community Atmosphere Model with Chemistry (CAM-Chem) we model that BrO and Br are the daytime dominant species. Integrated across all ATTREX flights, BrO represents ˜ 43 and 48 % of daytime Bry abundance at 17 km over the western and eastern Pacific, respectively. The results also show zones where Br / BrO > 1 depending on the solar zenith angle (SZA), ozone concentration, and temperature. On the other hand, BrCl and BrONO2 were found to be the dominant nighttime species with ˜ 61 and 56 % of abundance at 17 km over the western and eastern Pacific, respectively. The western-to-eastern differences in the partitioning of inorganic bromine are explained by different abundances of ozone (O3), nitrogen dioxide (NO2), total inorganic chlorine (Cly), and the efficiency of heterogeneous reactions of bromine reservoirs (mostly BrONO2 and HBr) occurring on ice crystals.

  11. Genetic species identification and population structure of Halophila (Hydrocharitaceae) from the Western Pacific to the Eastern Indian Ocean.

    Science.gov (United States)

    Nguyen, Vy X; Detcharoen, Matsapume; Tuntiprapas, Piyalap; Soe-Htun, U; Sidik, Japar B; Harah, Muta Z; Prathep, Anchana; Papenbrock, Jutta

    2014-04-30

    The Indo-Pacific region has the largest number of seagrass species worldwide and this region is considered as the origin of the Hydrocharitaceae. Halophila ovalis and its closely-related species belonging to the Hydrocharitaceae are well-known as a complex taxonomic challenge mainly due to their high morphological plasticity. The relationship of genetic differentiation and geographic barriers of H. ovalis radiation was not much studied in this region. Are there misidentifications between H. ovalis and its closely related species? Does any taxonomic uncertainty among different populations of H. ovalis persist? Is there any genetic differentiation among populations in the Western Pacific and the Eastern Indian Ocean, which are separated by the Thai-Malay peninsula? Genetic markers can be used to characterize and identify individuals or species and will be used to answer these questions. Phylogenetic analyses of the nuclear ribosomal internal transcribed spacer region based on materials collected from 17 populations in the Western Pacific and the Eastern Indian Ocean showed that some specimens identified as H. ovalis belonged to the H. major clade, also supported by morphological data. Evolutionary divergence between the two clades is between 0.033 and 0.038, much higher than the evolutionary divergence among H. ovalis populations. Eight haplotypes were found; none of the haplotypes from the Western Pacific is found in India and vice versa. Analysis of genetic diversity based on microsatellite analysis revealed that the genetic diversity in the Western Pacific is higher than in the Eastern Indian Ocean. The unrooted neighbor-joining tree among 14 populations from the Western Pacific and the Eastern Indian Ocean showed six groups. The Mantel test results revealed a significant correlation between genetic and geographic distances among populations. Results from band-based and allele frequency-based approaches from Amplified Fragment Length Polymorphism showed that all

  12. Homotopy perturbation method of equatorial eastern Pacific for the El Ni(n)o-Southern Oscillation mechanism

    Institute of Scientific and Technical Information of China (English)

    Mo Jia-Qi; Lin Wan-Tao

    2005-01-01

    The EI Ni(n)o/La Ni(n)a and the Southern Oscillation (ENSO) is an interannual phenomenon involved in the tropical Pacific ocean-atmosphere interactions. In this paper, the aim is to create an asymptotic solving method of nonlinear equation for the ENSO models. And based on a class of oscillator of the ENSO models, employing the method of homotopic mapping, the approximation solution of corresponding problem is studied. It is proven from the results that the homotopic method can be used for analysing the sea surface temperature anomaly in the equatorial eastern Pacific and the thermocline depth anomaly of the atmosphere-ocean oscillation for ENSO model.

  13. Expanding diversity in the mantis shrimps: two new genera from the eastern and western Pacific (Crustacea: Stomatopoda: Squillidae

    Directory of Open Access Journals (Sweden)

    Cara Van Der Wal

    Full Text Available Abstract Squillidae is the largest family in the Stomatopoda, with 47 genera to date. Phylogenetic analyses have shown Squilla Fabricius, 1787 and Oratosquilla Manning, 1968 to be para- or polyphyletic. Two poorly documented species within these genera, Squilla parva Bigelow, 1891 (eastern Pacific and Oratosquilla kempi (Schmitt, 1931 (western Pacific are not closely related to the respective type species of the genera in which they are currently placed. We herein redescribe S. parva and O. kempi based on type and other material, and propose two new genera for their reception, increasing the number of squillid genera to 49.

  14. Population structure and phylogeography reveal pathways of colonization by a migratory marine reptile (Chelonia mydas) in the central and eastern Pacific.

    Science.gov (United States)

    Dutton, Peter H; Jensen, Michael P; Frey, Amy; LaCasella, Erin; Balazs, George H; Zárate, Patricia; Chassin-Noria, Omar; Sarti-Martinez, Adriana Laura; Velez, Elizabeth

    2014-11-01

    Climate, behavior, ecology, and oceanography shape patterns of biodiversity in marine faunas in the absence of obvious geographic barriers. Marine turtles are an example of highly migratory creatures with deep evolutionary lineages and complex life histories that span both terrestrial and marine environments. Previous studies have focused on the deep isolation of evolutionary lineages (>3 mya) through vicariance; however, little attention has been given to the pathways of colonization of the eastern Pacific and the processes that have shaped diversity within the most recent evolutionary time. We sequenced 770 bp of the mtDNA control region to examine the stock structure and phylogeography of 545 green turtles from eight different rookeries in the central and eastern Pacific. We found significant differentiation between the geographically separated nesting populations and identified five distinct stocks (F ST = 0.08-0.44, P Chelonia mydas form a monophyletic group containing 3 subclades, with Hawaii more closely related to the eastern Pacific than western Pacific populations. The split between sampled central/eastern and western Pacific haplotypes was estimated at around 0.34 mya, suggesting that the Pacific region west of Hawaii has been a more formidable barrier to gene flow in C. mydas than the East Pacific Barrier. Our results suggest that the eastern Pacific was colonized from the western Pacific via the Central North Pacific and that the Revillagigedos Islands provided a stepping-stone for radiation of green turtles from the Hawaiian Archipelago to the eastern Pacific. Our results fit with a broader paradigm that has been described for marine biodiversity, where oceanic islands, such as Hawaii and Revillagigedo, rather than being peripheral evolutionary "graveyards", serve as sources and recipients of diversity and provide a mechanism for further radiation.

  15. Dissolved iron distribution in the tropical and sub tropical South Eastern Pacific

    Directory of Open Access Journals (Sweden)

    S. Blain

    2008-02-01

    Full Text Available Dissolved iron (DFe distributions (<0.2 μm were determined in the upper water column (0–400 m of the south eastern tropical and subtropical Pacific, in October–November 2004. Data were collected along a transect extending from the Marquesas Islands to the Chilean coast with most of the stations located in the south Pacific gyre. The concentrations of DFe presented large variability with highest values observed at both extremities of the transect. In the Chilean upwelling, DFe concentrations ranged between 1.2–3.9 nM. These high values result from inputs from the continental margin and are likely maintained by anoxic conditions in the water corresponding to the Oxygen Minimum Zone (OMZ. In subsurface waters near the Marquesas, that were also associated with the extension of the OMZ, DFe concentrations varied between 0.15–0.41 nM. Vertical transport of this water by mesoscale activity eastward of the archipelago may explain the dissymmetric east-west distribution of chlorophyll-a evidenced by satellite images. Using the new tracer Fe*=DFe−rFe:P (PO43− we show that DFe was in deficit compared to PO43− resulting from the remineralisation of organic matter. This suggests that the Marquesas islands and the surrounding plateau are not a significant source of DFe. In the gyre, DFe concentrations in the upper 350 m water column were around 0.1 nM and the ferricline was located well below the nitracline. These low concentrations reflect the low input of DFe from the atmosphere, from the ventilation of the upper thermocline with water containing low DFe, and from the low biological activity within this ultra oligotrophic gyre.

  16. Quaternary paleoceanographic reconstruction of Eastern Equatorial Pacific:planktic foraminiferal evidence

    Science.gov (United States)

    Mallick, Kirtiranjan; Sinha, Devesh K.; Singh, Ashutosh K.

    2016-04-01

    The Eastern Equatorial Pacific (EEP) is quite unique in its oceanographic set up and exhibits considerable variations on shorter to longer time scales. The region encounters intense upwelling caused by the Peru Current. The EEP show a strong ocean-atmosphere coupling, which is manifested in form of events like (El Nino Southern Oscillations (ENSO) that affects the global climate. The present work is based on planktic foraminiferal census data from the ODP Hole 846B, situated at 3°S latitude near the Galapagos spreading centre in the EEP, for paleoceanographic reconstructions for the Quaternary Period. Four species which show significant fluctuations in the relative abundance are Globigerinoides ruber (mixed layer and oligotrophic species), Neogloboquadrina dutertrei (fertility indicator and thermocline dweller),Globigerina bulloides (upwelling indicator) and Globorotalia inflata (temperate species). Results of the analyses of the census count of the planktic foraminifera indicate the overall dominance of the shallow water thermocline species N. dutertrei, suggesting the prevalence of the robust EEP Cold tongue during the Quaternary. The increase in the relative abundance of Gs.ruber marks seven planktic foraminiferal events (2.52Ma to 0.5Ma) of reduced strength of the cold tongue along the EEP. These intervals are concomitant with spreading and encroachment of warm water from the Western Pacific suggesting El Nino like conditions due to reduced strength of trade winds. Seven planktic foraminiferal events (2.42Ma to 0.20Ma) show prominent increase in the relative abundance of Gg.bulloides indicating advection of nutrient rich waters due to enhanced coastal upwelling. Invasion of the temperate species Globorotalia inflata is indicated by its abundance reaching up to 20 percent of the total assemblage at 3°S occur during ~ 2.07 Ma, 1.32 Ma and 1.05 Ma. The unusual occurrence of the cold water temperate species indicates the expansion of southern polar front which

  17. Late Holocene Sea Surface Temperature Trends in the Eastern Tropical Pacific

    Science.gov (United States)

    Rustic, G. T.; Koutavas, A.; Marchitto, T. M., Jr.

    2015-12-01

    The Eastern Tropical Pacific (ETP) is a highly dynamic ocean region capable of exerting influencing on global climate as illustrated by the El Niño-Southern Oscillation (ENSO). The sea surface temperature (SST) history of this region in past millennia is poorly constrained due to the lack of in situ records with appropriate resolution. Here we present a ~2700 year sub-centennially resolved SST reconstruction from Mg/Ca ratios of the planktonic foraminifer Globigerinoides ruber from Galápagos sediments. The ETP SST record exhibits a long-term cooling trend of over 0.2°C/ky that is similar to Northern Hemisphere multi-proxy temperature trends suggesting a common origin, likely due to insolation forcing. The ETP remains in-phase with Northern Hemisphere climate records through the warm Roman Climate Optimum (~0-400CE), cooler Dark Ages Cold Period (~450-850CE), and through the peak warming of the Medieval Climate Anomaly (900-1150 CE) when SST is within error of modern. Following peak MCA, the ETP cooled rapidly and then rebounded at ~1500 CE during the coldest portion of the Little Ice Age. Overall the data suggest an out-of-phase relationship during much of the last millennium, which we attribute to dynamical adjustments consistent with the "dynamical ocean thermostat" mechanism. Further evidence for these dynamical adjustments comes from reconstructions of the east-west zonal SST gradient using existing Mg/Ca SST reconstructions from the western Pacific warm pool. The last millennium has been the most dynamic period over the past 2700 years, with significant (~1 °C) SST variability in the ETP and modulation of the zonal gradient. A combination of dynamical and thermodynamic mechanisms are invoked to explain the region's complex SST history.

  18. Limited-are a modelling of stratocumulus over South-Eastern Pacific

    Directory of Open Access Journals (Sweden)

    M. Andrejczuk

    2012-04-01

    Full Text Available This paper presents application of the Weather Research and Forecasting (WRF model to limited-area modeling of atmospheric processes over the subtropical south-eastern Pacific, with the emphasis on the stratocumulus-topped boundary layer. The simulations cover a domain from the VAMOS (Variability of the American Monsoon Systems Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx field project conducted in the subtropical south-eastern Pacific in October and November 2008. We focus on a day where the UK's BAe-146 research aircraft encountered Pockets of Open Cells (POCs at the very western edge of its flight track, rather than on the entire campaign as investigated in previous limited-area modeling studies. Model results are compared to aircraft observations with the main conclusion that the simulated stratocumulus-topped boundary layer is significantly too shallow. This appears to be a combination of an already too shallow boundary layer in the dataset used to provide initial and lateral boundary conditions, and the inability of the WRF model to increase the boundary-layer height. Several sensitivity simulations, applying different subgrid-scale parameterizations available in the model, a larger computational domain and longer simulations, as well as a different dataset providing initial and lateral boundary conditions were all tried to improve the simulation. These changes appeared to have a rather small effect on the results. The model does simulate the formation of mesoscale cloud-free regions that one might consider similar to Pockets of Open Cells observed in nature. However, formation of these regions does not seem to be related to drizzle-induced transition from open- to closed-cell circulations as simulated by LES models. Instead, the cloud-free regions appear to result from mesoscale variations of the lower-tropspheric vertical velocity. Areas of negative vertical velocity with minima (a few cm s−1 near the

  19. Temperature profile data from BATHYTHERMOGRAPH (XBT) from LEXA MAERSK and other platforms in the eastern Pacific Ocean and southern Atlantic Ocean: 19880526 to 19890911 (NODC Accession 9000078)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The water depth and temperature data was collected from ships such as Lexa Maersk and 14 other ships. The data was collected from Eastern Pacific Ocean and Southern...

  20. AFSC/RACE/FBEP/Hurst: Distributional patterns of 0-group Pacific cod (Gadus macrocephalus) in the eastern Bering Sea under variable recruitment and thermal conditions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is from a study that analyzed the late summer distribution of juvenile Pacific cod in the eastern Bering Sea for 6 cohorts (2004-2009), based on catches...

  1. Convection and Easterly Wave Structure Observed in the Eastern Pacific Warm-Pool during EPIC-2001

    Science.gov (United States)

    Peterson, Walter A.; Cifelli, R.; Boccippio, D.; Rutledge, S. A.; Fairall, C. W.; Arnold, James E. (Technical Monitor)

    2002-01-01

    During September-October 2001, the East Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System (EPIC-2001) ITCZ field campaign focused on studies of deep convection in the warm-pool region of the East Pacific. In addition to the TAO mooring array, observational platforms deployed during the field phase included the NOAA ship RN Ronald H. Brown, the NSF ship RN Horizon, and the NOAA P-3 and NCAR C-130 aircraft. This study combines C-band Doppler radar, rawinsonde, and surface heat flux data collected aboard the RN Brown to describe ITCZ convective structure and rainfall statistics in the eastern Pacific as a function of 3-5 day easterly wave phase. Three distinct easterly wave passages occurred during EPIC-2001. Wind and thermodynamic data reveal that the wave trough axes exhibited positively correlated U and V winds and a slight westward phase tilt with height. A relatively strong (weak) northeasterly deep tropospheric shear followed the trough (ridge) axis. Temperature and humidity perturbations exhibited mid-to upper level cooling (warming) and drying (moistening) in the northerly (trough and southerly) phase. At low levels warming (cooling) occurred in the northerly (southerly) phase with little change in the relative humidity, though mixed layer mixing ratios were larger during the northerly phase. When composited, radar, sounding, lightning and surface heat flux observations suggest the following systematic behavior as a function of wave phase: approximately zero to one quarter wavelength ahead of (behind) the wave trough in northerly (southerly) flow, larger (smaller) CAPE, lower (higher) CIN, weaker (stronger) tropospheric shear, higher (lower) conditional mean rain rates, higher (lower) lightning flash densities, and more (less) robust convective vertical structure occurred. Latent and sensible heat fluxes reached a minimum in the northerly phase and then increased through the trough, reaching a peak during the ridge phase

  2. REE and (э)Nd of clay fractions in sediments from the eastern Pacific Ocean: Evidence for clay sources

    Institute of Scientific and Technical Information of China (English)

    LIU Jihua; SHI Xuefa; CHEN Lirong; HUANG Yongyang; WANG Yinxi; CUI Yingchun; BU Wenrui

    2005-01-01

    Clay fractions in the non-calcareous surface sediments from the eastern Pacific were analyzed for clay minerals, REE and 143Nd/144Nd. Montmorillonite/illite ratio (M/I ratio), total REE contents ((REE), LREE/HREE ratio and cerium anomaly (бCe) may effectively indicate the genesis of clay minerals. Clay fractions with M/I ratio >1, бCe (0.85, (REE (400 μg/g, LREE/HREE ratio (4, and REE patterns similar to those of pelagic sediments are terrigenous and autogenetic mixed clay fractions and contain more autogenetic montmorillonite. Clay fractions with M/I ratio <1, бCe=0.86 to 1.5, ΣREE=200 to 350 μg/g, LREE/HREE ratio (6 and REE distribution patterns similar to that of China loess are identified as terrigenous clay fraction. The 143Nd/144Nd ratios or (э)Nd values of clay fractions inherit the features of terrigenous sources of clay minerals. Clay fractions are divided into 4 types according to (э)Nd values. Terrigenous clay minerals of type I with the (э)Nd values of -8 to -6 originate mainly from North American fluvial deposits. Those of type II with the (э)Nd values of -9 to -7 are mainly from the East Asia and North American fluvial deposits. Those of type III with (э)Nd values of -6 to -3 could come from the central and eastern Pacific volcanic islands. Those of type IV with (э)Nd values of -13 to -12 may be from East Asia eolian. The terrigenous and autogenetic mixed clay fractions show patchy distributions, indicating that there are volcanic or hot-spot activities in the eastern Pacific plate, while the terrigenous clay fractions cover a large part of the study area, proving that the terrigenous clay minerals are dominant in the eastern Pacific.

  3. Lowermost mantle anisotropy near the eastern edge of the Pacific LLSVP: constraints from SKS-SKKS splitting intensity measurements

    Science.gov (United States)

    Deng, Jie; Long, Maureen D.; Creasy, Neala; Wagner, Lara; Beck, Susan; Zandt, George; Tavera, Hernando; Minaya, Estela

    2017-08-01

    Seismic anisotropy has been documented in many portions of the lowermost mantle, with particularly strong anisotropy thought to be present along the edges of large low shear velocity provinces (LLSVPs). The region surrounding the Pacific LLSVP, however, has not yet been studied extensively in terms of its anisotropic structure. In this study, we use seismic data from southern Peru, northern Bolivia and Easter Island to probe lowermost mantle anisotropy beneath the eastern Pacific Ocean, mostly relying on data from the Peru Lithosphere and Slab Experiment and Central Andean Uplift and Geodynamics of High Topography experiments. Differential shear wave splitting measurements from phases that have similar ray paths in the upper mantle but different ray paths in the lowermost mantle, such as SKS and SKKS, are used to constrain anisotropy in D″. We measured splitting for 215 same station-event SKS-SKKS pairs that sample the eastern Pacific LLSVP at the base of the mantle. We used measurements of splitting intensity(SI), a measure of the amount of energy on the transverse component, to objectively and quantitatively analyse any discrepancies between SKS and SKKS phases. While the overall splitting signal is dominated by the upper-mantle anisotropy, a minority of SKS-SKKS pairs (˜10 per cent) exhibit strongly discrepant splitting between the phases (i.e. the waveforms require a difference in SI of at least 0.4), indicating a likely contribution from lowermost mantle anisotropy. In order to enhance lower mantle signals, we also stacked waveforms within individual subregions and applied a waveform differencing technique to isolate the signal from the lowermost mantle. Our stacking procedure yields evidence for substantial splitting due to lowermost mantle anisotropy only for a specific region that likely straddles the edge of Pacific LLSVP. Our observations are consistent with the localization of deformation and anisotropy near the eastern boundary of the Pacific LLSVP

  4. Microbes adapt to iron scarcity through siderophore production across the eastern tropical Pacific

    Science.gov (United States)

    Repeta, D.; Boiteau, R.; Mende, D. R.; DeLong, E.

    2016-02-01

    Iron regulates microbial growth and carbon fixation rates in vast regions of the ocean characterized by high nutrient and low chlorophyll (HNLC) concentrations. As competition for bioavailable iron in HNLC regions intensifies, microbial communities face tremendous selective pressure to develop efficient uptake and utilization strategies that access the strong organic ligands controlling iron bioavailability in these areas. Using liquid chromatography mass spectrometry, we found 27 unique iron complexes in surface waters sampled across the GEOTRACES eastern tropical Pacific zonal cruise track, with a clear trend in the abundance of different ligands across nutrient regimes. We identified siderophores, compounds produced by microbes under iron stress to facilitate iron uptake, as important components of iron ligands. Siderophore composition varied dramatically across the region, reflecting adaptive microbial strategies for acquiring iron. Concentrations of amphibactins, amphiphilic siderophores with cell membrane affinity, were low in coastal waters, but reached 9pM in HNLC waters, while ferrioxamine concentrations were higher in coastal and oligotrophic regions (1-2pM). These spatial changes in siderophore distributions represents adaptations used by marine microbes to acquire iron under different ecological conditions. To infer the potential ocean-wide contribution of amphibactins to microbial iron acquisition, we investigated the distribution of amphibactin synthesis genes in the recently published TARA Oceans metagenomic catalogue. We found amphibactin synthesis genes were present in other major iron-starved regions, suggesting that adaptations involving siderophore utilization likely impact global marine ecosystem composition and productivity.

  5. Nitrous oxide production in the eastern tropical South Pacific oxygen minimum zone

    Science.gov (United States)

    Ji, Qixing; Altabet, Mark; Arevalo-Martinez, Damian; Bange, Hermann; Ma, Xiao; Marandino, Christa; Sun, Mingshuang; Grundle, Damian

    2017-04-01

    Nitrous oxide (N2O) is an important climate active trace gas that contributes to both atmospheric warming and ozone destruction, and the ocean is an important source of N2O to the atmosphere. Dissolved oxygen concentrations play an important role in regulating N2O production in the ocean, such that under low oxygen conditions major shifts in the predominant production pathways (i.e. nitrification vs. denitrification) can occur and the magnitude of production may increase substantially. To this end, major oceanic oxygen minimum zones (OMZs) are responsible for a disproportionately high amount of marine N2O production. During the October 2015 ASTRA-OMZ cruise to the eastern tropical South Pacific (ETSP), one of the three major oceanic OMZs, we measured a suite of N2O parameters which included N2O concentrations, N2O production, and natural abundance N2O isotope (i.e. del 15N and del 18O) and isotopomer (i.e. 15N site-preference) signatures. Based on the results from these measurements, our presentation will demonstrate how N2O production and the different production pathways change along the oxygen concentration gradients from the oxygenated surface waters through the oxygen minimum layer. Our data could better constrain the importance of the ETSP-OMZ as source of marine N2O. Results from this work will provide insights into how N2O cycling responds to ocean deoxygenation as a result of climate change.

  6. Bite force and feeding kinematics in the eastern North Pacific Kyphosidae.

    Science.gov (United States)

    Moran, Clinton Joseph; Ferry, Lara

    2014-04-01

    Some fishes that feed on attached food items possess an intramandibular joint (IMJ), which is thought to increase maximum gape and facilitate contact between the tooth-bearing surface and the substrate. However, the mechanical consequences of using an IMJ to remove attached food items from the substrate are still poorly understood. We examined the most prominent eastern North Pacific kyphosid, the scraper: Girella nigricans and two other kyphosids, Medialuna californiensis and Hermosilla azurea, which occupy similar habitats. Of the three species, G. nigricans had the highest theoretical bite force per unit length. We examined the feeding mechanics of G. nigricans in two different feeding scenarios: a scraping behavior elicited on a block of brine shrimp gelatin and a picking behavior elicited on Ulva sp. We measured cranial elevation, lower jaw rotation, premaxillary protrusion, premaxillary rotation, gape maximum, and intramandibular rotation. Ulva treatments produced significantly greater cranial rotation, when compared to gelatin treatments. Gelatin treatments were associated with greater lower jaw rotation and larger gape. Premaxillary rotation and premaxillary protrusion did not differ between treatments. Intramandibular rotation occurred only when G. nigricans physically contacted the gelatin, suggesting the IMJ is a passive joint with no associated musculature. We also noted that G. nigricans do not appear to use suction to draw food into the mouth. The lack of suction and the presence of the IMJ suggest that the jaws of G. nigricans are specialized for maximizing jaw force when scraping.

  7. Critically endangered western gray whales migrate to the eastern North Pacific.

    Science.gov (United States)

    Mate, Bruce R; Ilyashenko, Valentin Yu; Bradford, Amanda L; Vertyankin, Vladimir V; Tsidulko, Grigory A; Rozhnov, Vyacheslav V; Irvine, Ladd M

    2015-04-01

    Western North Pacific gray whales (WGWs), once considered extinct, are critically endangered with unknown migratory routes and reproductive areas. We attached satellite-monitored tags to seven WGWs on their primary feeding ground off Sakhalin Island, Russia, three of which subsequently migrated to regions occupied by non-endangered eastern gray whales (EGWs). A female with the longest-lasting tag visited all three major EGW reproductive areas off Baja California, Mexico, before returning to Sakhalin Island the following spring. Her 22 511 km round-trip is the longest documented mammal migration and strongly suggests that some presumed WGWs are actually EGWs foraging in areas historically attributed to WGWs. The observed migration routes provide evidence of navigational skills across open water that break the near-shore north-south migratory paradigm of EGWs. Despite evidence of genetic differentiation, these tagging data indicate that the population identity of whales off Sakhalin Island needs further evaluation. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  8. A revision of the genus Muricea Lamouroux, 1821 (Anthozoa, Octocorallia) in the eastern Pacific. Part II.

    Science.gov (United States)

    Breedy, Odalisca; Guzman, Hector M

    2016-01-01

    The species of the genus Muricea were mainly described from 1846 to 1870. After that very few contributions were published. Although the highest richness of Muricea species is in the eastern Pacific shallow waters, a comprehensive systematic study of the genus does not exist. Recently we started a taxonomic review of the genus in order to validate the status of four species previously included in the genus Eumuricea. Herein we present the second part of the Muricea revision dealing with the species-group characterised by shelf-like calyces instead of tubular-like calyces (the Muricea squarrosa-group). Original type material was morphologically analysed and illustrated using optical and scanning electron microscopy. Comparative character tables are provided for the genus. The taxonomic status of the species was analysed and established by designating lectotypes, alternatively by recognising a holotype by monotypy. We conclude that the genus Muricea comprises 20 valid species, including the previous four in the Muricea squarrosa-group. We propose 10 lectotypes, a new combination and three more species groups for the genus based on morphology: the Muricea fruticosa-group, Muricea plantaginea-group and Muricea austera-group.

  9. Gradients in Strong and Weak Organic Copper-Binding Ligands in the Eastern Tropical South Pacific

    Science.gov (United States)

    Ruacho, A.; Bundy, R.; Barbeau, K.; Parker, C.; Roshan, S.; Wu, J.

    2014-12-01

    Dissolved organic copper-binding ligands were examined on the U.S. GEOTRACES zonal transect in the Eastern Tropical South Pacific from Peru to Tahiti. All samples were measured using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV), and a subset were analyzed using multiple competition strengths of the added ligand salicylaldoxime (1, 2.5, 5, 10, and 25 μM). Titration data was processed using newly available multiple analytical window data processing techniques, which unify the multiple window dataset as a whole. Multiple competition strengths of the added ligand enabled the detection of an additional weaker class of copper-binding ligand, compared to the two stronger ligand classes which have been measured previously in the open ocean. The strongest ligand class (L1) ranged in concentration from 1-10 nmol L-1 and had a conditional stability constant (logK) ranging from approximately 15.0-16.0. The weaker ligand classes (L2, and L3) were present in much higher concentrations even in surface waters, with concentrations ranging from 5-50 nmol L-1 and conditional stability constants ranging from 8.6-12.5. The elevated ligand concentrations, both in surface and deep waters, lead to extremely low concentrations of Cu2+ throughout the transect, possibly influencing important biogeochemical processes such as inducible iron acquisition by diatoms, and ammonium oxidation in the oxygen minimum zone.

  10. Copper Speciation Results From The U.S. GEOTRACES Eastern Tropical South Pacific Cruise

    Science.gov (United States)

    Ruacho, A.; Bundy, R.; Barbeau, K.; Parker, C.; Bruland, K. W.; Roshan, S.; Wu, J.

    2016-02-01

    Dissolved organic copper-binding ligands were examined on the U.S. GEOTRACES zonal transect in the Eastern Tropical South Pacific from Peru to Tahiti. All samples were measured using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV), the bulk in duplicate titrations at a single analytical window (5 µM) using the added ligand salicylaldoxime (SA). A subset of samples were also analyzed using multiple competition strengths (1, 2.5, 5, 10, and 25 µM added SA), along with equilibration tests at each analytical window. Titration data was processed using newly available software for single and multiple analytical window data. Equilibration tests conducted at the various analytical windows showed no significant differences in ligand concentration and binding strength between overnight vs. 15-30 minute equilibration times. Samples analyzed at a single window reveal excess strong ligands in the coastal region over the oxygen minimum zone with a conditional stability constant (logK) around 14. Multiple competition strengths of the added ligand enabled the detection of up to three classes of copper-binding ligands, with conditional stability constants ranging from 8.6-16.0, and high concentrations of weaker ligands throughout the water column. The presence of strong copper-binding ligands across the transect led to low free copper concentrations, which can be limiting to some phytoplankton. Analysis is ongoing and this presentation will summarize the status of this unique data set.

  11. Halogens, OVOC and H2O Distributions over the Eastern Pacific Ocean during TORERO

    Science.gov (United States)

    Dix, B. K.; Apel, E. C.; Baidar, S.; Zondlo, M. A.; Volkamer, R.

    2013-12-01

    As part of the Tropical Ocean tRoposphere Exchange of Reactive halogen species and Oxygenated VOC (TORERO) field project 17 research flights were conducted with the NSF/NCAR GV aircraft over the Eastern Tropical Pacific Ocean (42S to 14N Lat.; 70W to 105W Long). Equipped with a combination of chemical in-situ sensors and remote sensing instruments, a broad spectrum of reactive halogen species, oxygenated hydrocarbons, and aerosols were measured over different ocean environments. Using optical remote sensing (airborne Multi Axis DOAS), we measured iodine monoxide (IO), bromine monoxide (BrO), glyoxal (CHOCHO) and water vapor among others. A newly developed parameterization method allowed us to directly convert the measured slant column densities into mixing ratios along the whole flight track. Atmospheric reactive halogen species and organic carbon are important, because they modify HOx radical abundances, influence the reactive chemistry and lifetime of climate active gases (e.g., ozone, methane, dimethyl sulfide), modify aerosol-cloud interactions and halogen radicals can also oxidize atmospheric mercury. Here we summarize and evaluate the spatial distribution of IO, BrO and glyoxal over the TORERO study area. For select case studies we present comparisons to halogen precursors and OVOCs measured in-situ by on-line mass spectrometry (trace organic gas analyzer). The correlation of remotely observed water vapor to in-situ measurements further allows us to conclude on the homogeneity of spatial scales covered by both remote and in-situ sensors.

  12. Insight into the Pacific Sea Surface Temperature- North American Hydroclimate Connection from an Eastern Tropical North Pacific Coral Record

    Science.gov (United States)

    Sanchez, S. C.; Charles, C. D.; Carriquiry, J. D.

    2015-12-01

    The last few years of record-breaking climate anomalies across North America--a resilient atmospheric ridge and extreme drought over the West Coast, and severe winters across the Midwest and East Coast regions--have been linked to anomalous Pacific sea surface temperatures (Seager et al. 2014, Wang et al. 2014, Hartmann 2015). The synoptic associations prompt important questions on the relation between these unusual phenomena and extreme expressions of known Pacific decadal modes, such as the North Pacific Gyre Oscillation (NPGO). These questions motivate our pursuit to document multiple realizations of decadal variability in the Pacific-North American region through periods of varied radiative forcing. Here we introduce a 178 year, seasonally resolved Porites coral record from Clarion Island (18N, 115W), the westernmost island of the Revillagigedo Archipelago, a region both highly influenced by NPGO SST and SSS variability and critical for NPGO tropical-extratropical communication via the Seasonal Footprinting Mechanism (Vimont et al. 2003). When coupled with tree ring records from the western United States (Griffin and Anchukaitis 2014, MacDonald and Case 2005) and coral records from the central tropical Pacific (Cobb et al. 2001), the δ18O signal from the Clarion coral offers an extended framework of coherent continental hydroclimate and oceanic variability across the Pacific basin beyond the instrumental record. Over the last 200 years, we find clear commonality in the timing, magnitude and spatial expression of variability (illustrated through the NADA Atlas, Cook et al. 2004) amongst the proxy records. The strong relationship between Northeastern Pacific Clarion and the Central Pacific Palmyra record with the North American hydroclimate records can be viewed within the mechanistic framework of the NPGO; this framework is then explored over the last millennium across intervals of varied radiative forcing.

  13. Impacts of decaying eastern and central Pacific El Niños on tropical cyclone activities over the western North Pacific in summer

    Science.gov (United States)

    Yang, Yuxing; Xie, Ruihuang; Wang, Faming; Huang, Fei

    2016-07-01

    We investigate the influences of the decaying eastern Pacific El Niño (EP-El Niño) and central Pacific El Niño (CP-El Niño) on tropical cyclone (TC) activities in the western North Pacific (WNP) during July, August, and September (JAS). During this period, TC geneses and tracks are reduced in the central and eastern WNP. However, TC tracks reaching the Philippines increase, and more TC geneses appear west of 145°E during EP-El Niño. During CP-El Niño, tracks reaching the South China Sea (SCS) and southeast coast of China increase, and positive anomalies of TC genesis are found in the southern part of the central WNP and southern SCS. It is possible that the different variations of the anomalous anticyclone over east of the Philippines in the WNP induced by El Niños are instrumental to the different TC variations in the two types of decaying El Niños during JAS. Compared with EP-El Niño, strengthening and northward expansion of the anomalous anticyclone during CP-El Niño cause a westward shift of the western Pacific subtropical high in summer, which is responsible for more westward TC tracks over the SCS and southeast coast of China. This northward expansion can cause the center of suppressed TC geneses in the central WNP to migrate further north during CP-El Niño. A decreased magnitude of vertical shear dominates the southern part of the central WNP and southern SCS, which enhances TC formation in these regions during CP-El Niño.

  14. Increase in water column denitrification during the deglaciation controlled by oxygen demand in the eastern equatorial Pacific

    Directory of Open Access Journals (Sweden)

    P. Martinez

    2009-05-01

    Full Text Available Here we present organic export production and isotopic nitrogen results over the last 30 000 years from one core localized off Costa Rica (ODP Site 1242 on the leading edge of the oxygen minimum zone of the Eastern Tropical North Pacific. Marine export production reveals glacial-interglacial variations with low organic matter (total organic carbon and total nitrogen contents during warm intervals, twice more during cold episodes and double peaked maximum during the deglaciation, between ~15.5–18.5 and 11–13 ka BP. When this new export production record is compared with four nearby cores localized within the Eastern Pacific along the Equatorial divergence, a good agreement between all the cores is observed, with the major feature being a maximum of export during the early deglaciation. As for export production, water-column denitrification represented by sedimentary δ15N records along the Eastern tropical North and South Pacific between 15° N and 36° S is coherent as well over the last deglaciation period. The whole isotopic nitrogen profiles indicate that denitrification increased abruptly at 19 ka BP to a maximum during the early deglaciation, confirming a typical Antarctic timing. It is proposed that the increase in export production and then in subsurface oxygen demand lead to an intensification of water-column denitrification within the oxygen minimum zones in the easternmost Pacific at the time of the last deglaciation. The triggering mechanism would have been primarily linked to an increase in preformed nutrients contents feeding the Equatorial Undercurrent driven by the resumption of overturning in the Southern Ocean and the return of nutrients from the deep ocean to the sea-surface. An increase in equatorial wind-driven upwelling of sub-surface nutrient-rich waters could have played the role of an amplifier.

  15. Evidence for a Southern Pattern of Deglacial Surface Warming in the Eastern Equatorial Pacific

    Science.gov (United States)

    Spero, H. J.; Schmidt, M. W.; Lea, D. W.; Lavagnino, L.

    2009-12-01

    The timing of both Southern and Northern hemisphere warming patterns has been used to explain tropical Pacific warming at the end of the last glacial period. Despite the importance of resolving this deglacial tropical-polar connection, the controversy is still ongoing (Koutavas & Sachs, 2008; Lea et al., 2000, 2006). For instance, the initiation of eastern equatorial Pacific (EEP) surface warming, derived from Mg/Ca analyses of the surface-dwelling foraminifera Globigerinoides ruber, shows a clear correlation with the Southern hemisphere. In contrast, alkenone-derived temperatures from the EEP indicate tropical warming occurred at least 3 kyr later than that implied from Mg/Ca data, thereby suggesting a Northern hemisphere link to initial SST rise. Here, we use a multispecies, multiproxy approach that is based on fundamental foraminifera biology to resolve this controversy. Laboratory experiments demonstrate the final shell size of symbiont-bearing foraminifera varies primarily as a function of the light level (=symbiont photosynthetic rate) that an individual grew under. Because light decreases exponentially in the water column, and the EEP is highly stratified with a shallow mixed layer and cold thermocline, we hypothesize that symbiotic foraminifera with a broad habitat range such as Globigerinoides sacculifer, should produce smaller shells in the more dimly lit cold thermocline than individuals growing in the more illuminated mixed layer. Moreover, these larger shells should contain a temperature signal that is similar to G. ruber, which is constrained to the shallow mixed layer. Mg/Ca and δ18O analyses conducted on 350-400 μm and >650 μm sized G. sacculifer from EEP core TR163-19 (2N, 91W, 2348) demonstrate large specimens yield Mg/Ca and δ18O that are similar to data published previously for mixed layer dwelling G. ruber. In contrast, small G. sacculifer record significantly higher δ18O and lower Mg/Ca temperatures that are consistent with a shallow

  16. Late Quaternary Alluvial Fans of Southern Baja California, Mexico: Relation to Eastern Pacific Tropical Cyclones

    Science.gov (United States)

    Antinao, J.; McDonald, E.

    2009-12-01

    In the arid, non-glaciated regions of the Southwestern USA and Northwestern Mexico, aggradation in alluvial fan systems has been traditionally linked to cold and humid periods (e.g., Last Glacial Maximum) or to the transition to warm periods (e.g., the Pleistocene-Holocene transition, PHT). However, major intervals of sediment transport and aggradation have also occurred during climatically warm periods in these regions. These periods have also been identified as portraying enhanced humidity or “monsoonal’ conditions. Investigations on the weather systems able to perform geomorphic work during predominantly warm periods, i.e. the North American Monsoon (NAM) and Eastern Pacific (EP) Tropical Cyclones (TCs), have concentrated mainly in the USA. To understand the relative contribution of these systems to sediment transport over millennial timescales, we have mapped and characterized preliminarily the alluvial fans in four different areas of the Southern Baja California peninsula, Mexico. This region is dominated by EPTC precipitation, which in turn is driving the sediment transport along alluvial channels. Detailed geomorphologic mapping shows that a distinct Late Quaternary chronostratigraphy of alluvial fan units can be developed using geochronological and pedological tools. Specifically, a soil chronosequence can be compared to sequences in the SW USA, allowing a correlation to Late Pleistocene - Holocene events in the region. At least five alluvial units can be identified. Older units have well defined gravel pediments, Av and B horizons and pervasive pedogenic carbonate morphology, with alluvial terraces that rise tens of meters above the present channel. Intermediate age units have developed B horizons and carbonate morphology at different stages. The younger units have thin soil horizons, no carbonate morphology in the soil profile, and some of them are subject to episodic flooding during TC activity. The chronosequence developed is the first step towards

  17. Simulation of the intraseasonal variability over the Eastern Pacific ITCZ in climate models

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xianan [Univ. of California, Los Angeles, CA (United States); Waliser, Duane E. [California Inst. of Technology (CalTech), La Canada Flintridge, CA (United States). Jet Propulsion Lab.; Kim, Daehyun [Columbia Univ., New York, NY (United States); Zhao, Ming [Princeton Univ., NJ (United States); Sperber, Kenneth R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stern, William F. [Princeton Univ., NJ (United States); Schubert, Siegfried D. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Zhang, Guang J. [Scripps Institute of Oceanography. La Jolla, California (United States); Wang, Wanqiu [National Oceanic and Atmospheric Administration (NOAA), National Centers for Environmental Protection. Camp Springs, MD (United States); Khairoutdinov, Marat [Institute for Terrestrial and Planetary Atmospheres. Stony Brook Univ., NY (United States); Neale, Richard B. [National Center for Atmospheric Research. Boulder, CO (United States); Lee, Myong-In [Ulsan National Institute for Science and Technology. Seoul (Korea)

    2012-08-01

    During boreal summer, convective activity over the eastern Pacific (EPAC) inter-tropical convergence zone (ITCZ) exhibits vigorous intraseasonal variability (ISV). Previous observational studies identified two dominant ISV modes over the EPAC, i.e., a 40-day mode and a quasi-biweekly mode (QBM). The 40-day ISV mode is generally considered a local expression of the Madden-Julian Oscillation. However, in addition to the eastward propagation, northward propagation of the 40-day mode is also evident. The QBM mode bears a smaller spatial scale than the 40-day mode, and is largely characterized by northward propagation. While the ISV over the EPAC exerts significant influences on regional climate/weather systems, investigation of contemporary model capabilities in representing these ISV modes over the EPAC is limited. In this study, the model fidelity in representing these two dominant ISV modes over the EPAC is assessed by analyzing six atmospheric and three coupled general circulation models (GCMs), including one super-parameterized GCM (SPCAM) and one recently developed high-resolution GCM (GFDL HIRAM) with horizontal resolution of about 50 km. While it remains challenging for GCMs to faithfully represent these two ISV modes including their amplitude, evolution patterns, and periodicities, encouraging simulations are also noted. In general, SPCAM and HIRAM exhibit relatively superior skill in representing the two ISV modes over the EPAC. While the advantage of SPCAM is achieved through explicit representation of the cumulus process by the embedded 2-D cloud resolving models, the improved representation in HIRAM could be ascribed to the employment of a strongly entraining plume cumulus scheme, which inhibits the deep convection, and thus effectively enhances the stratiform rainfall. The sensitivity tests based on HIRAM also suggest that fine horizontal resolution could also be conducive to realistically capture the ISV over the EPAC, particularly for the QBM mode

  18. Marine biodiversity of an Eastern Tropical Pacific oceanic island, Isla del Coco, Costa Rica

    Directory of Open Access Journals (Sweden)

    Jorge Cortés

    2012-11-01

    Full Text Available Isla del Coco (also known as Cocos Island is an oceanic island in the Eastern Tropical Pacific; it is part of the largest national park of Costa Rica and a UNESCO World Heritage Site. The island has been visited since the 16th Century due to its abundance of freshwater and wood. Marine biodiversity studies of the island started in the late 19th Century, with an intense period of research in the 1930’s, and again from the mid 1990’s to the present. The information is scattered and, in some cases, in old publications that are difficult to access. Here I have compiled published records of the marine organisms of the island. At least 1688 species are recorded, with the gastropods (383 species, bony fishes (354 spp. and crustaceans (at least 263 spp. being the most species-rich groups; 45 species are endemic to Isla del Coco National Park (2.7% of the total. The number of species per kilometer of coastline and by square kilometer of seabed shallower than 200m deep are the highest recorded in the Eastern Tropical Pacific. Although the marine biodiversity of Isla del Coco is relatively well known, there are regions that need more exploration, for example, the south side, the pelagic environments, and deeper waters. Also, several groups of organisms, such as the flatworms, nematodes, nemerteans, and gelatinous zooplankton, have been observed around the Island but have been poorly studied or not at all.La Isla del Coco es una isla oceánica en el Pacífico Tropical Oriental; es parte del Parque Nacional más grande de Costa Rica y es un sitio de Patrimonio Mundial. La isla ha sido visitada desde el Siglo XVI por su abundancia de agua dulce y árboles. Estudios de biodiversidad marina de la isla empezaron a finales del Siglo XIX, con un intenso período de investigación en la década de 1930, y de nuevo desde mediados de la década de 1990 al presente. La información sobre organismos marinos se encuentra dispersa y en algunos casos en publicaciones

  19. Geocemical provinces of magmatism in the south-eastern part of the Pacific Ocean

    Science.gov (United States)

    Sushchevskaya, Nadezhda; Belyatsky, Boris; Teterin, Dmitry

    2010-05-01

    Comparison of geochemical signatures of island magmatism in the south-eastern part of the Pacific Ocean and tholeiites of the Bransfield and Powell rift zones revealed the similar character of the enrichment which reflects the melting of a close mantle source. But alkaline magmatism of the islands in the west of Antarctic and Marie Byrd Land differs from the enriched basalts of the northern province (Bransfield, Powell, BTJ) by showing more radiogenic Sr values and non-radiogenic Nd. The tectonic development of the South Ocean is characterized by its formation under stationary conditions of Antarctic continent. As a result of this, for the volcanic islands distributed at the western part of the Antarctic we observe no long mountain ridges typical for their development under conditions of the moving plate. Intraplate magmatism evolution was coincided with the extinction of the old subduction zones, formation of the new rift zones and separation of South America from Antarctic [Udintsev, Schenke, 2007; Teterin, 2008]. Such complicated geodynamics caused the possibility of formation of rupture cracks reaching the underlying metasomatizated mantle and decompression melting with further island formation. In Oligocene due to migration of asthenospheric flow from the west to east in the result of destruction of previously united continental blocks there was formed the Scotia Sea, South Sandwich island arc as well as Drake Passage. This caused the mechanical weakening of South Atlantic lithosphere and the starting at the end of Oligocene - beginning Miocene of the new plate border formation - American-Antarctic ridge, which propagated in the eastern direction till the Bouvet triple junction [Dubinin et al., 1999]. The close geochemical signatures of mantle source for islands basalts including the Bouvet Island and the enriched tholeiites of the western extremity of the SW Indian Ridge proves the development of a specific geochemical province enveloping the southeastern

  20. Abraham's children in the genome era: major Jewish diaspora populations comprise distinct genetic clusters with shared Middle Eastern Ancestry.

    Science.gov (United States)

    Atzmon, Gil; Hao, Li; Pe'er, Itsik; Velez, Christopher; Pearlman, Alexander; Palamara, Pier Francesco; Morrow, Bernice; Friedman, Eitan; Oddoux, Carole; Burns, Edward; Ostrer, Harry

    2010-06-11

    For more than a century, Jews and non-Jews alike have tried to define the relatedness of contemporary Jewish people. Previous genetic studies of blood group and serum markers suggested that Jewish groups had Middle Eastern origin with greater genetic similarity between paired Jewish populations. However, these and successor studies of monoallelic Y chromosomal and mitochondrial genetic markers did not resolve the issues of within and between-group Jewish genetic identity. Here, genome-wide analysis of seven Jewish groups (Iranian, Iraqi, Syrian, Italian, Turkish, Greek, and Ashkenazi) and comparison with non-Jewish groups demonstrated distinctive Jewish population clusters, each with shared Middle Eastern ancestry, proximity to contemporary Middle Eastern populations, and variable degrees of European and North African admixture. Two major groups were identified by principal component, phylogenetic, and identity by descent (IBD) analysis: Middle Eastern Jews and European/Syrian Jews. The IBD segment sharing and the proximity of European Jews to each other and to southern European populations suggested similar origins for European Jewry and refuted large-scale genetic contributions of Central and Eastern European and Slavic populations to the formation of Ashkenazi Jewry. Rapid decay of IBD in Ashkenazi Jewish genomes was consistent with a severe bottleneck followed by large expansion, such as occurred with the so-called demographic miracle of population expansion from 50,000 people at the beginning of the 15th century to 5,000,000 people at the beginning of the 19th century. Thus, this study demonstrates that European/Syrian and Middle Eastern Jews represent a series of geographical isolates or clusters woven together by shared IBD genetic threads.

  1. Fluorescence signatures of an iron-enriched phytoplankton community in the eastern equatorial Pacific Ocean

    Science.gov (United States)

    Hoge, Frank E.; Wayne Wright, C.; Swift, Robert N.; Yungel, James K.; Berry, Richard E.; Mitchell, Richard

    Laser-induced fluorescence profiles of chlorophyll and phycoerythrin pigments and chromophoric dissolved organic matter (CDOM) fluorescence acquired over an iron-enriched phytoplankton patch are compared to profiles made over adjacent, naturally occurring phytoplankton patches. A total of four airborne missions were flown during an 8 day period following the release of the iron-rich fertilizer. Analyses of the airborne laser-induced fluorescence profiles from the upper-ocean layer reveal: (1) Ship-dispersed iron enhances localized phytoplankton production in high-nutrient/low-chlorophyll regions such as found in the eastern equatorial Pacific Ocean. (2) The chlorophyll concentration within the iron-enriched phytoplankton patch exceeded levels of chlorophyll found in naturally occurring phytoplankton patches located outside the enriched region. (3) An increase in phycoerythrin fluorescence was observed within the enriched region in correspondence with the elevated chlorophyll fluorescence. However, the phycoerythrin/chlorophyll fluorescence ratio was lower within the enriched patch than in naturally occurring phytoplankton patches outside of the enriched region. (4) No above-background chromorophoric dissolved organic matter (CDOM) fluorescence was observed in the enriched patch. Elevated CDOM fluorescence was associated with some of the naturally occurring phytoplankton patches outside the enriched region, while other such phytoplankton patches showed no measurable increase in CDOM over background levels. (5) The surface layer manifestation of the patch was observed to be transported to the north and west in close agreement with the drogue positions. No elevated surface layer chlorophyll fluorescence was seen in the vicinity of the ship as it sampled the submerged fraction at the time of the 30 October and 1 November overflights. The phycoerythrin pigment fluorescence emission was insensitive to ambient cloud-induced downwelling irradiance variability, while at the

  2. Early diagenetic quartz formation at a deep iron oxidation front in the Eastern Equatorial Pacific

    Science.gov (United States)

    Meister, Patrick; Chapligin, Bernhard; Picard, Aude; Meyer, Hanno; Fischer, Cornelius; Rettenwander, Daniel; Amthauer, Georg; Vogt, Christoph; Aiello, Ivano

    2015-04-01

    The mechanisms of early diagenetic quartz formation under low-temperature conditions are still poorly understood. We studied lithified cherts consisting of microcrystalline quartz recovered from ODP Site 1226 in the Eastern Equatorial Pacific. The cherts occur near the base of a 420-m-thick Miocene-Holocene sequence within unlithified nannofossil and diatom ooze. Palaeo-temperatures reconstructed from δ18O values in the cherts are near to present porewater temperatures and a sharp depletion in dissolved silica occurs around 385 mbsf indicating that silica precipitation is still ongoing. Also a deep iron oxidation front occurs at the same depth, which is caused by upward diffusing nitrate from an oxic seawater aquifer in the underlying basaltic crust. Sequential iron extraction and analysis of the X-ray absorption near-edge structure (XANES) revealed that iron in the cherts predominantly occurs as illite and amorphous iron oxide, whereas iron in the nannofossil and diatom ooze occurs mainly as smectites. Mössbauer spectroscopy confirmed that the illite iron in the cherts is largely oxidized. A possible mechanisms that may be operative is quartz precipitation initiated by adsorption of silica to freshly precipitated iron oxides. The decrease in porewater silica concentration below opal-A and opal-CT saturation then allows for the precipitation of the thermodynamically more stable phase: quartz. We suggest that the formation of early-diagenetic chert at iron oxidation fronts is an important process in suboxic zones of silica-rich sediments. The largest iron oxidation front ever occurred during the great oxidation event ca. 2.5 Ga ago, when large amounts of iron and chert beds were deposited.

  3. Revisiting nitrification in the Eastern Tropical South Pacific: A focus on controls

    Science.gov (United States)

    Peng, Xuefeng; Fuchsman, Clara A.; Jayakumar, Amal; Warner, Mark J.; Devol, Allan H.; Ward, Bess B.

    2016-03-01

    Nitrification, the oxidation of ammonium (NH4+) to nitrite (NO2-) and to nitrate (NO3-), is a component of the nitrogen (N) cycle internal to the fixed N pool. In oxygen minimum zones (OMZs), which are hotspots for oceanic fixed N loss, nitrification plays a key role because it directly supplies substrates for denitrification and anaerobic ammonia oxidation (anammox), and may compete for substrates with these same processes. However, the control of oxygen and substrate concentrations on nitrification are not well understood. We performed onboard incubations with 15N-labeled substrates to measure rates of NH4+ and NO2- oxidation in the eastern tropical South Pacific (ETSP). The spatial and depth distributions of NH4+ and NO2- oxidation rates were primarily controlled by NH4+ and NO2- availability, oxygen concentration, and light. In the euphotic zone, nitrification was partially photoinhibited. In the anoxic layer, NH4+ oxidation was negligible or below detection, but high rates of NO2- oxidation were observed. NH4+ oxidation displayed extremely high affinity for both NH4+ and oxygen. The positive linear correlations between NH4+ oxidation rates and in situ NH4+ concentrations and ammonia monooxygenase subunit A (amoA) gene abundances in the upper oxycline indicate that the natural assemblage of ammonia oxidizers responds to in situNH4+ concentrations or supply by adjusting their population size, which determines the NH4+ oxidation potential. The depth distribution of archaeal and bacterial amoA gene abundances and N2O concentration, along with independently reported simultaneous direct N2O production rate measurements, suggests that AOA were predominantly responsible for NH4+ oxidation, which was a major source of N2O production at oxygen concentrations > 5 µM.

  4. Authigenic gypsum found in gas hydrate-associated sediments from Hydrate Ridge, the eastern North Pacific

    Institute of Scientific and Technical Information of China (English)

    WANG; Jiasheng; Erwin; Suess; Dirk; Rickert

    2004-01-01

    Characteristic gypsum micro-sphere and granular mass were discovered by binocular microscope in the gas hydrate-associated sediments at cores SO143-221 and SO143/TVG40-2A respectively on Hydrate Ridge of Cascadia margin, the eastern North Pacific. XRD patterns and EPA analyses show both micro-sphere and granular mass of the crystals have the typical peaks and the typical main chemical compositions of gypsum, although their weight percents are slightly less than the others in the non-gas hydrate-associated marine regions. SEM pictures show that the gypsum crystals have clear crystal boundaries, planes, edges and cleavages of gypsum in form either of single crystal or of twin crystals. In view of the fact that there are meanwhile gas hydrate-associated authigenic carbonates and SO42(-rich pore water in the same sediment cores, it could be inferred reasonably that the gypsums formed also authigenically in the gas hydrate-associated environment too, most probably at the interface between the downward advecting sulfate-rich seawater and the below gas hydrate, which spilled calcium during its formation on Hydrate Ridge. The two distinct forms of crystal intergrowth, which are the granular mass of series single gypsum crystals at core SO143/TVG40-2A and the microsphere of gypsum crystals accompanied with detrital components at core SO143-221 respectively, indicate that they precipitated most likely in different interstitial water dynamic environments. So, the distinct authigenic gypsums found in gas hydrate-associated sediments on Hydrate Ridge could also be believed as one of the parameters which could be used to indicate the presence of gas hydrate in an unknown marine sediment cores.

  5. Contribution of picoplankton to the total particulate organic carbon (POC concentration in the eastern South Pacific

    Directory of Open Access Journals (Sweden)

    C. Grob

    2007-05-01

    Full Text Available Prochlorococcus, Synechococcus, picophytoeukaryotes and bacterioplankton abundances and contributions to the total particulate organic carbon concentration (POC, derived from the total particle beam attenuation coefficient (cp, were determined across the eastern South Pacific between the Marquesas Islands and the coast of Chile. All flow cytometrically derived abundances decreased towards the hyper-oligotrophic centre of the gyre and were highest at the coast, except for Prochlorococcus, which is not detected under eutrophic conditions. Temperature and nutrient availability appeared important in modulating picophytoplankton abundance, according to the prevailing trophic conditions. Although the non-vegetal particles tended to dominate the cp signal everywhere along the transect (50 to 83%, this dominance seemed to weaken from oligo- to eutrophic conditions, the contributions by vegetal and non-vegetal particles being about equal under mature upwelling conditions. Spatial variability in the vegetal compartment was more important than the non-vegetal one in shaping the water column particulate attenuation coefficient. Spatial variability in picophytoplankton biomass could be traced by changes in both Tchla and cp. Finally, picophytoeukaryotes contributed with ~38% on average to the total integrated phytoplankton carbon biomass or vegetal attenuation signal along the transect, as determined by direct size measurements on cells sorted by flow cytometry and optical theory. The role of picophytoeukaryotes in carbon and energy flow would therefore be very important, even under hyper-oligotrophic conditions.

  6. Atmosphere-ocean linkages in the eastern equatorial Pacific over the early Pleistocene

    Science.gov (United States)

    Povea, Patricia; Cacho, Isabel; Moreno, Ana; Pena, Leopoldo D.; Menéndez, Melisa; Calvo, Eva; Canals, Miquel; Robinson, Rebecca S.; Méndez, Fernando J.; Flores, Jose-Abel

    2016-05-01

    Here we present a new set of high-resolution early Pleistocene records from the eastern equatorial Pacific (EEP). Sediment composition from Ocean Drilling Program Sites 1240 and 1238 is used to reconstruct past changes in the atmosphere-ocean system. Particularly remarkable is the presence of laminated diatom oozes (LDOs) during glacial periods between 1.85 and 2.25 Ma coinciding with high fluxes of opal and total organic carbon. Relatively low lithic particles (coarse and poorly sorted) and iron fluxes during these glacial periods indicate that the increased diatom productivity did not result from dust-stimulated fertilization events. We argue that glacial fertilization occurred through the advection of nutrient-rich waters from the Southern Ocean. In contrast, glacial periods after 1.85 Ma are characterized by enhanced dust transport of finer lithic particles acting as a new source of nutrients in the EEP. The benthic ecosystem shows dissimilar responses to the high productivity recorded during glacial periods before and after 1.85 Ma, which suggests that the transport processes delivering organic matter to the deep sea also changed. Different depositional processes are interpreted to be the result of two distinct glacial positions of the Intertropical Convergence Zone (ITCZ). Before 1.85 Ma, the ITCZ was above the equator, with weak local winds and enhanced wet deposition of dust. After 1.85 Ma, the glacial ITCZ was displaced northward, thus bringing stronger winds and stimulating upwelling in the EEP. The glacial period at 1.65 Ma with the most intense LDOs supports a rapid southward migration of the ITCZ comparable to those glacial periods before 1.85 Ma.

  7. Chemical composition of marine stratocumulus clouds over the eastern Pacific Ocean

    Science.gov (United States)

    Straub, Derek J.; Lee, Taehyoung; Collett, Jeffrey L.

    2007-02-01

    Samples of marine cloud water collected over the eastern Pacific Ocean have been analyzed for pH, major ions (Cl-, NO3-, SO42-, Na+, NH4+, K+, Ca2+, and Mg2+), hydrogen peroxide, formaldehyde, S(IV), Fe, Mn, and total organic carbon. The samples were obtained during the Dynamics and Chemistry of Marine Stratocumulus, Phase II (DYCOMS-II) field project in July 2001. These measurements represent a unique in situ description of cloud water composition for stratocumulus clouds residing in the remote marine boundary layer, a regime for which there are few published cloud water composition data. A wide range of concentrations was observed for each species of interest, including sodium (36-2784 μN), sulfate (15-905 μN), nitrate (3-205 μN), hydrogen peroxide (37.8-283.2 μM), formaldehyde (2.2-8.7 μM) and Fe (water concentrations with cloud liquid water content (LWC) and volume mean drop diameter show that dilution played a role in cloud drop solute concentration variations during individual flights and that solute concentrations are related to cloud drop size and ultimately to below-cloud aerosol number concentration. Air equivalent concentrations (the amount of a solute in cloud water per unit volume of air) were derived in order to eliminate concentration dependence on LWC and to allow comparison with previous aerosol, trace gas, and cloud water studies. The analysis indicates that background marine conditions were not always encountered during the DYCOMS-II mission as a result of anthropogenic or biogenic sources impacting the study region.

  8. Multiple metabolisms constrain the anaerobic nitrite budget in the Eastern Tropical South Pacific

    Science.gov (United States)

    Babbin, Andrew R.; Peters, Brian D.; Mordy, Calvin W.; Widner, Brittany; Casciotti, Karen L.; Ward, Bess B.

    2017-02-01

    The Eastern Tropical South Pacific is one of the three major oxygen deficient zones (ODZs) in the global ocean and is responsible for approximately one third of marine water column nitrogen loss. It is the best studied of the ODZs and, like the others, features a broad nitrite maximum across the low oxygen layer. How the microbial processes that produce and consume nitrite in anoxic waters interact to sustain this feature is unknown. Here we used 15N-tracer experiments to disentangle five of the biologically mediated processes that control the nitrite pool, including a high-resolution profile of nitrogen loss rates. Nitrate reduction to nitrite likely depended on organic matter fluxes, but the organic matter did not drive detectable rates of denitrification to N2. However, multiple lines of evidence show that denitrification is important in shaping the biogeochemistry of this ODZ. Significant rates of anaerobic nitrite oxidation at the ODZ boundaries were also measured. Iodate was a potential oxidant that could support part of this nitrite consumption pathway. We additionally observed N2 production from labeled cyanate and postulate that anammox bacteria have the ability to harness cyanate as another form of reduced nitrogen rather than relying solely on ammonification of complex organic matter. The balance of the five anaerobic rates measured—anammox, denitrification, nitrate reduction, nitrite oxidation, and dissimilatory nitrite reduction to ammonium—is sufficient to reproduce broadly the observed nitrite and nitrate profiles in a simple one-dimensional model but requires an additional source of reduced nitrogen to the deeper ODZ to avoid ammonium overconsumption.

  9. Paleoceanography and the diachrony of radiolarian events in the eastern equatorial Pacific

    Science.gov (United States)

    Moore, T. C.; Skackleton, N. J.; Pisias, N. G.

    1993-10-01

    The development of an orbitally tuned time scale for the ODP leg 138 sites provides biostratigraphers a very high resolution chronostratigraphic framework. With this framework we are better able to define which of the first and last appearances of species appear to be synchronous. In addition, the geographic distribution of sites provides the means with which the detailed spatial patterns of invasion of new species and the extinction of older species can be mapped. These maps not only provide information on the process of evolution, migration, and extinction, they can also be related to water mass distributions and near-surface circulation of the ocean. Of 39 radiolarian events studied at 11 sites in the eastern equatorial Pacific, 28 were found to have a minimum range in their estimated age that exceeded 0.15 m.y. The temporal pattern of first and last appearances of these diachronous events have coherent spatial patterns that indicate shifts in the areas of high oceanographic gradients over the past 10 Ma. These changes in the locations of high gradient regions suggest that the South Equatorial Current (SEC) was north of its present position prior to approximately 7 Ma. There was a southward shift in the northern boundary of this current between approximately 6 and 7 Ma, and the development of a relatively strong gradient between the northeastern and northwestern sites. Between approximately 3.7 and 3.4 Ma, there was a very slight northward shift in the northern boundary of the SEC and the steep gradients between the northeastern and northwestern sites may have disappeared. This change is thought to be associated with the closing of the Isthmus of Panama. The temporal-spatial patterns of diachronous events younger than 3.4 Ma are consistent with patterns of circulation in the modern ocean.

  10. N2 fixation in eddies of the eastern tropical South Pacific Ocean

    Science.gov (United States)

    Loscher, Carolin R.; Bourbonnais, Annie; Dekaezemacker, Julien; Charoenpong, Chawalit N.; Altabet, Mark A.; Bange, Hermann W.; Czeschel, Rena; Hoffmann, Chris; Schmitz, Ruth

    2016-05-01

    Mesoscale eddies play a major role in controlling ocean biogeochemistry. By impacting nutrient availability and water column ventilation, they are of critical importance for oceanic primary production. In the eastern tropical South Pacific Ocean off Peru, where a large and persistent oxygen-deficient zone is present, mesoscale processes have been reported to occur frequently. However, investigations into their biological activity are mostly based on model simulations, and direct measurements of carbon and dinitrogen (N2) fixation are scarce.We examined an open-ocean cyclonic eddy and two anticyclonic mode water eddies: a coastal one and an open-ocean one in the waters off Peru along a section at 16° S in austral summer 2012. Molecular data and bioassay incubations point towards a difference between the active diazotrophic communities present in the cyclonic eddy and the anticyclonic mode water eddies.In the cyclonic eddy, highest rates of N2 fixation were measured in surface waters but no N2 fixation signal was detected at intermediate water depths. In contrast, both anticyclonic mode water eddies showed pronounced maxima in N2 fixation below the euphotic zone as evidenced by rate measurements and geochemical data. N2 fixation and carbon (C) fixation were higher in the young coastal mode water eddy compared to the older offshore mode water eddy. A co-occurrence between N2 fixation and biogenic N2, an indicator for N loss, indicated a link between N loss and N2 fixation in the mode water eddies, which was not observed for the cyclonic eddy. The comparison of two consecutive surveys of the coastal mode water eddy in November 2012 and December 2012 also revealed a reduction in N2 and C fixation at intermediate depths along with a reduction in chlorophyll by half, mirroring an aging effect in this eddy. Our data indicate an important role for anticyclonic mode water eddies in stimulating N2 fixation and thus supplying N offshore.

  11. Late quaternary sea bottom conditions in the southern Panama basin, Eastern Equatorial Pacific

    Science.gov (United States)

    Patarroyo, German D.; Martínez, José I.

    2015-11-01

    A paleoceanographic reconstruction of the southern Panama Basin for the last 23.000 years, based on the benthic foraminiferal analysis from the deep sea core ME0005A-24JC (0.01°N, 86.28°W, water depth 2941) is presented. Cluster and SHEBI (SHE Analysis for Biozone Identification) analyses performed on the benthic foraminiferal assemblages, evidence a faunal turnover in the early Holocene at 14 ky BP. Between 23 and 14 ky BP, Fursenkoina rotundata, Hoeglundina elegans, Globobulimina affinis, Globobulimina pacifica, Cibicidoides wuellerstorfi and Uvigerina hispidocostata were common. Conversely, from 14 ky to the present, the assemblage is represented by Chilostomella oolina, Laticarinina pauperata, and Uvigerina proboscidea. This faunal turnover suggests significant fluctuations in oxygen content at the sea floor and the organic matter (OM) influx, which could reflect: (1) fluctuations in the surface productivity related to the equatorial divergence and, (2) OM advection caused by the dynamic of the deep sea currents. Paleoproductivity estimates and benthic foraminiferal rates depict a general trend towards lower values since the Last Glacial Maximum (LGM) with a conspicuous change at 14 ky BP. Therefore, the paleoceanographic reconstructions of the ME0005A-24JC core suggest a transition from La Niña-like conditions during the LGM to El Niño-like conditions in the recent, as previously proposed for the Eastern Equatorial Pacific. Estimates of the paleo-intensity of deep sea currents based on the relative percentage abundance of the epifaunal foraminifera Cibicidoides wuellerstorfi suggest stronger deep sea currents on the Carnegie Ridge before 14 ky BP.

  12. Decadal variability in the occurrence of wintertime haze in central eastern China tied to the Pacific Decadal Oscillation

    Science.gov (United States)

    Zhao, Sen; Li, Jianping; Sun, Cheng

    2016-06-01

    Haze is a serious issue in China with increasing concerns, and understanding the factors driving decadal-scale variations in haze occurrence is relevant for government policymaking. Using a comprehensive observational haze dataset, we demonstrate notable decadal fluctuations in the number of haze days (HD) during winter in central eastern China, showing a decline since the mid-1980s. The leading mode of the wintertime HD features an increasing trend for 1959-2012 in eastern China, highly correlated with China’s gross domestic product (GDP) that represents increasing trend of pollutant emissions, and to a lesser extent meteorological factors. The second mode shows decadal variations in central eastern China associated with Pacific Decadal Oscillation (PDO). Observations and numerical simulations suggest that Mongolia High and corresponding descending motion tend to be enhanced (weakened) in central eastern China during the positive (negative) phase of PDO. With PDO shifting towards a negative phase, the weakened Mongolia High and ascending anomalies make the air unstable and conduce to the spread of pollutants, leading to the decline in the wintertime HD over central eastern China since the mid-1980s. Based on above physical mechanisms, a linear model based on PDO and GDP metrics provided a good fit to the observed HD.

  13. Decadal variability in the occurrence of wintertime haze in central eastern China tied to the Pacific Decadal Oscillation.

    Science.gov (United States)

    Zhao, Sen; Li, Jianping; Sun, Cheng

    2016-06-10

    Haze is a serious issue in China with increasing concerns, and understanding the factors driving decadal-scale variations in haze occurrence is relevant for government policymaking. Using a comprehensive observational haze dataset, we demonstrate notable decadal fluctuations in the number of haze days (HD) during winter in central eastern China, showing a decline since the mid-1980s. The leading mode of the wintertime HD features an increasing trend for 1959-2012 in eastern China, highly correlated with China's gross domestic product (GDP) that represents increasing trend of pollutant emissions, and to a lesser extent meteorological factors. The second mode shows decadal variations in central eastern China associated with Pacific Decadal Oscillation (PDO). Observations and numerical simulations suggest that Mongolia High and corresponding descending motion tend to be enhanced (weakened) in central eastern China during the positive (negative) phase of PDO. With PDO shifting towards a negative phase, the weakened Mongolia High and ascending anomalies make the air unstable and conduce to the spread of pollutants, leading to the decline in the wintertime HD over central eastern China since the mid-1980s. Based on above physical mechanisms, a linear model based on PDO and GDP metrics provided a good fit to the observed HD.

  14. ENSO signals on sea-surface salinity in the eastern tropical pacific ocean

    Directory of Open Access Journals (Sweden)

    1998-01-01

    types collected in the tropical Pacific are analyzed to assess the regional impacts of past (1972-1996 El Niño Southern Oscillation (ENSO events. Focus is made on the regional changes in sea-surface temperature and salinity. Commercial vessels were recently equipped with automated thermosalinographs which allows to monitor the location of salinity front along the Panama-Tahiti line, separating the Panama Gulf from the South Pacific water masses. The latitudinal change of the salinity front is well correlated with the latitudinal change of the ITCZ. Salinity distribution gives additional information on El-Niño development. How future real time SSS data might provide interesting information on the development of ENSO phenomenon in the eastern tropical Pacific area will be discussed.

  15. The record-breaking 2015 hurricane season in the eastern North Pacific: An analysis of environmental conditions

    Science.gov (United States)

    Collins, Jennifer M.; Klotzbach, Philip J.; Maue, Ryan N.; Roache, David R.; Blake, Eric S.; Paxton, Charles H.; Mehta, Christopher A.

    2016-09-01

    The presence of a near-record El Niño and a positive Pacific Meridional Mode provided an extraordinarily warm background state that fueled the 2015 eastern North Pacific hurricane season to near-record levels. We find that the western portion of the eastern North Pacific, referred to as the Western Development Region (WDR; 10°-20°N, 116°W-180°), set records for named storms, hurricane days, and Accumulated Cyclone Energy in 2015. When analyzing large-scale environmental conditions, we show that record warm sea surface temperatures, high midlevel relative humidity, high low-level relative vorticity, and record low vertical wind shear were among the environmental forcing factors contributing to the observed tropical cyclone activity. We assess how intraseasonal atmospheric variability may have contributed to active and inactive periods observed during the 2015 hurricane season. We document that, historically, active seasons are associated with May-June El Niño conditions, potentially allowing for predictability of future active WDR seasons.

  16. Antarctic-type blue whale calls recorded at low latitudes in the Indian and eastern Pacific Oceans

    Science.gov (United States)

    Stafford, Kathleen M.; Bohnenstiehl, DelWayne R.; Tolstoy, Maya; Chapp, Emily; Mellinger, David K.; Moore, Sue E.

    2004-10-01

    Blue whales, Balaenoptera musculus, were once abundant around the Antarctic during the austral summer, but intensive whaling during the first half of the 20th century reduced their numbers by over 99%. Although interannual variability of blue whale occurrence on the Antarctic feeding grounds was documented by whalers, little was known about where the whales spent the winter months. Antarctic blue whales produce calls that are distinct from those produced by blue whales elsewhere in the world. To investigate potential winter migratory destinations of Antarctic blue whales, we examined acoustic data for these signals from two low-latitude locales: the eastern tropical Pacific Ocean and the Indian Ocean. Antarctic-type blue whale calls were detected on hydrophones in both regions during the austral autumn and winter (May-September), with peak detections in July. Calls occurred over relatively brief periods in both oceans, suggesting that there may be only a few animals migrating so far north and/or producing calls. Antarctic blue whales appear to use both the Indian and eastern Pacific Oceans concurrently, indicating that there is not a single migratory destination. Acoustic data from the South Atlantic and from mid-latitudes in the Indian or Pacific Oceans are needed for a more global understanding of migratory patterns and destinations of Antarctic blue whales.

  17. Temporal size changes of Miocene planktonic foraminifera Paragloborotalia siakensis in the eastern Equatorial Pacific associated with Mi-events

    Science.gov (United States)

    Okada, H.; Hayashi, H.

    2013-12-01

    Temporal changes in test size of planktonic foraminifera have been variously studied as a key for knowing evolution related to paleoceanographic changes. With respect to recent studies, rapid size reducing ('dwarfing') in several species have been observed around the last occurrence horizon. Generically, size changes of calcareous nannofossils have been used for global correlation. However, there are few previous studies of such temporal size changes for Miocene planktonic foraminifera. Paragloborotalia siakensis (LeRoy, 1939) is one of important index species in the middle Miocene. The upper boundary of planktonic foraminieral Zone N.14 is defined by the top occurrence of this species. It is a well known fact that P. siakensis is a dominant species in the tropical high-productivity area such as the eastern equatorial Pacific. The aims of this study are to reveal size changes of P. siakensis collected from IODP Site U1338 in the eastern equatorial Pacific and to correlate the size changes with paleoceanographic events. We measured maximum length of P. siakensis (50-200 individuals for each horizon) at approximately every 0.1 million years from 16.0 to 10.5 Ma. At the same time, we also conducted morphometric analyses of selected five horizons (14.96 Ma, 14.03 Ma, 13.00 Ma, 12.29 Ma and 11.11 Ma) by means of image analysis software (ImageJ). According to the morphometric analyses, the population from Site U1338 should be compared with the holotype of P. siakensis. The maximum length of P. siakensis shows significant reducing ('dwarfing') at cooling intervals inferred by previous studies based on alkenone and isotope data. It is possible to say that dwarfing of P. siakensis at Site U1338 might be induced by shallowing of the thermocline in the eastern equatorial Pacific.

  18. ON THE RELATIONSHIPS BETWEEN THE SUMMER RAINFALL IN CHINA AND THE ATMOSPHERIC HEAT SOURCES OVER THE EASTERN TIBETAN PLATEAU AND THE WESTERN PACIFIC WARM POOL

    Institute of Scientific and Technical Information of China (English)

    简茂球; 罗会邦; 乔云亭

    2004-01-01

    The relationships between the summer rainfall in China and the atmospheric heat sources over the eastern Tibetan Plateau and the western Pacific warm pool were analyzed comparatively, using the NCEP/NCAR reanalysis daily data. The strong (weak) heat source in summer over the eastern Tibetan Plateau will lead to abundant (scarce) summer rainfall in the Yangtze River basin, and scarce/abundant summer rainfall in the eastern part of Southern China. While the strong (weak) heat source in summer over the western Pacific warm pool will lead to another pattern of abundant (scarce) summer rainfall in the middle-lower reaches of the Yangtze River and scarce (abundant) summer rainfall in Southern China and in the region of northern Jiangsu to southern Shandong. Comparatively, the heat source over the eastern Tibetan Plateau affects a larger area of summer rainfall than the heat source over the western Pacific. In both cases of the heat source anomalies over the eastern Tibetan Plateau and over the western Pacific, there exist EAP-like teleconnection patterns in East Asia. The summer rainfall in China is influenced directly by the abnormal vertical motion, which is related closely to the abnormal heat sources in the atmosphere. The ridge line of the western Pacific High locates far south (north) in summer in the case of strong (weak) heat sources over the two areas mentioned above.

  19. Health risk assessment from mercury levels in bycatch fish species from the coasts of Guerrero, Mexico (Eastern Pacific).

    Science.gov (United States)

    Spanopoulos-Zarco, P; Ruelas-Inzunza, J; Meza-Montenegro, M; Osuna-Sánchez, K; Amezcua-Martínez, F

    2014-09-01

    With the aim of determining Hg distribution in muscle and liver of bycatch fish from Guerrero state in the Eastern Pacific Ocean and assess the potential risk to consumer, Hg was quantified in 14 species of bycatch fish. For the majority of fish the order of Hg levels was liver > muscle. The highest concentration corresponded to the liver of Isopisthus remifer (2.05 µg g(-1)) and the lowest (0.02 µg g(-1)) was detected in muscle of Prionotus sp. The highest hazard quotient (0.75) was found in the Mexican milkfish Micropogonias ectenes; considering all the individuals, mean hazard quotient was 0.336.

  20. Fatty acids as biomarkers for food web structure in the eastern North Pacific Ocean

    Science.gov (United States)

    Behrens, J.; Aluwihare, L.; Stephens, B. M.

    2015-12-01

    Resulting from a NSF funded REU program at Scripps Institution of Oceanography in 2015, this research utilized gas chromatography-mass spectrometry (GC-MS) to analyze the fatty acid composition of suspended particulate organic matter (POM) and zooplankton (ZP; primarily copepods). Samples analyzed for this study were collected simultaneously from surface waters approximately 9 miles off the coast of San Diego in June 2015. I was testing the hypothesis that essential fatty acids in ZP should reflect their diet, in particular, distinguishing contributions from a microbial versus traditional food web. Food web structure in this region of the ocean has been shown to be sensitive to climate change on inter-annual and longer timescales. Thus, a proxy that identifies restructuring of food webs would be useful for examining the response of ocean ecosystems to future climate change. Lipids were extracted from ZP and POM using a modified Bligh and Dyer method with sonication. Following saponification free fatty acids and other lipids were further purified using column chromatography. Polar functional groups in lipids were then methylated prior to GC-MS analysis. In addition, 2-dimensional GCxGC with time of flight MS was used to distinguish polyunsaturated fatty acid isomers. My poster will present initial findings of shared fatty acids of zooplankton and POM suspended material from the Northern Pacific collection site. Further research will be focused on analyzing the hydrogen isotope composition of fatty acids in zooplankton and suspended DOM obtained at the collection site to further characterize and increase certainty on the role of microbes and phytoplankton in the region's food-web to distinguish prokaryotic and eukaryotic sources.

  1. Evaluating controls on planktonic foraminiferal geochemistry in the Eastern Tropical North Pacific

    Science.gov (United States)

    Gibson, Kelly Ann; Thunell, Robert C.; Machain-Castillo, Maria Luisa; Fehrenbacher, Jennifer; Spero, Howard J.; Wejnert, Kate; Nava-Fernández, Xinantecatl; Tappa, Eric J.

    2016-10-01

    To explore relationships between water column hydrography and foraminiferal geochemistry in the Eastern Tropical North Pacific, we present δ18O and Mg/Ca records from three species of planktonic foraminifera, Globigerinoides ruber, Globigerina bulloides, and Globorotalia menardii, collected from a sediment trap mooring maintained in the Gulf of Tehuantepec from 2006-2012. Differences in δ18O between mixed-layer species G. ruber and G. bulloides and thermocline-dweller G. menardii track seasonal changes in upwelling. The records suggest an increase in upwelling during the peak positive phase of El Niño, and an overall reduction in stratification over the six-year period. For all three species, Mg/Ca ratios are higher than what has been reported in previous studies, and show poor correlations to calcification temperature. We suggest that low pH (7.6-8.0) and [3 2-CO] values (∼70-120 μmol/kg) in the mixed layer contribute to an overall trend of higher Mg/Ca ratios in this region. Laser Ablation Inductively Coupled Mass Spectrometry analyses of G. bulloides with high Mg/Ca ratios (>9 mmol/mol) reveal the presence of a secondary coating of inorganic calcite that has Mg/Ca and Mn/Ca ratios up to an order of magnitude higher than these elemental ratios in the primary calcite, along with elevated Sr/Ca and Ba/Ca ratios. Some of the samples with abnormally high Mg/Ca are found during periods of high primary productivity, suggesting the alteration may be related to changes in carbonate saturation resulting from remineralization of organic matter in oxygen-poor waters in the water column. Although similar shell layering has been observed on fossil foraminifera, this is the first time such alteration has been studied in shells collected from the water column. Our results suggest a role for seawater carbonate chemistry in influencing foraminiferal calcite trace element:calcium ratios prior to deposition on the seafloor, particularly in high-productivity, low

  2. Biogeochemical characteristics of a long-lived anticyclonic eddy in the eastern South Pacific Ocean

    Science.gov (United States)

    Cornejo D'Ottone, Marcela; Bravo, Luis; Ramos, Marcel; Pizarro, Oscar; Karstensen, Johannes; Gallegos, Mauricio; Correa-Ramirez, Marco; Silva, Nelson; Farias, Laura; Karp-Boss, Lee

    2016-05-01

    Mesoscale eddies are important, frequent, and persistent features of the circulation in the eastern South Pacific (ESP) Ocean, transporting physical, chemical and biological properties from the productive shelves to the open ocean. Some of these eddies exhibit subsurface hypoxic or suboxic conditions and may serve as important hotspots for nitrogen loss, but little is known about oxygen consumption rates and nitrogen transformation processes associated with these eddies. In the austral fall of 2011, during the Tara Oceans expedition, an intrathermocline, anticyclonic, mesoscale eddy with a suboxic (Water (ESSW) that at this latitude is normally restricted to an area near the coast. Measurements of nitrogen species within the eddy revealed undersaturation (below 44 %) of nitrous oxide (N2O) and nitrite accumulation (> 0.5 µM), suggesting that active denitrification occurred in this water mass. Using satellite altimetry, we were able to track the eddy back to its region of formation on the coast of central Chile (36.1° S, 74.6° W). Field studies conducted in Chilean shelf waters close to the time of eddy formation provided estimates of initial O2 and N2O concentrations of the ESSW source water in the eddy. By the time of its offshore sighting, concentrations of both O2 and N2O in the subsurface oxygen minimum zone (OMZ) of the eddy were lower than concentrations in surrounding water and "source water" on the shelf, indicating that these chemical species were consumed as the eddy moved offshore. Estimates of apparent oxygen utilization rates at the OMZ of the eddy ranged from 0.29 to 44 nmol L-1 d-1 and the rate of N2O consumption was 3.92 nmol L-1 d-1. These results show that mesoscale eddies affect open-ocean biogeochemistry in the ESP not only by transporting physical and chemical properties from the coast to the ocean interior but also during advection, local biological consumption of oxygen within an eddy further generates conditions favorable to

  3. Rain ratio variation in the Tropical Ocean: Tests with surface sediments in the eastern equatorial Pacific

    Science.gov (United States)

    Mekik, Figen; Loubere, Paul; Richaud, Mathieu

    2007-03-01

    The organic carbon to calcite flux ratio (rain ratio) has a profound effect on the preservation of carbonates in the deep sea and may influence atmospheric pCO 2 over millennia. Unfortunately, the degree to which the rain ratio varies in the more productive regions of the oceans is not well determined with sediment trap data. The rain ratio in the upper ocean appears dominantly linked to diatom productivity, which is not necessarily directly linked to total production and may be regionally variable. However, ballasting and protection of organic carbon by calcareous particles in the deeps may limit ratio variability at the seafloor. Sediment trap data do not exist for the regional determination of rain ratios in key highly productive areas like the eastern equatorial Pacific (EEP). To overcome this, we turn to surface sediment composition and accumulation rates as a representation of modern ratio variation. We present 230Thorium ( 230Th)-normalized carbonate, opal, organic carbon and detrital matter accumulation rates from core top samples in the EEP. We demonstrate a novel approach for estimating modern rain ratios from sedimentary proxies by (1) calculating vertical calcite flux from 230Th-normalized carbonate accumulation rates (CARs) with correction for preservation and (2) calculating organic carbon fluxes with multiple algorithms that depend in varying degrees on ballasting. We find that organic carbon flux estimates from algorithms with and without a ballasting function produce results different from one another. Sediment accumulation rates for opal reflect the likely pattern of diatom production. By contrast, the organic carbon accumulation rate does not correlate well with surface ocean productivity or any of our algorithm-based organic carbon flux estimates. Instead, it correlates with the detrital component of the sediments suggesting an allochthonous input to sedimentary organic carbon accumulation in the EEP, which reduces its value as a productivity

  4. Understanding TEX86H Temperature Estimates in the Eastern Equatorial Pacific over the Last Deglacial

    Science.gov (United States)

    Randle, N. J.; Schmidt, M. W.; Bianchi, T. S.; Hertzberg, J. E.; Shields, M. R.

    2014-12-01

    An index based on the relative abundance of glycerol dialkyl glycerol tetraethers (TEX86) has been gaining support for use as a sea surface temperature proxy. It has had limited application in the Eastern Equatorial Pacific (EEP) and, prior to this study, has not been applied to a high-resolution record within this region. Here, we utilize the TEX86H temperature index to calculate a North-South temperature gradient in the EEP over the last ~25 kyr using two sediment cores, MV1014-02-17JC (located within the equatorial upwelling zone on the Carnegie Ridge) and MV1014-01-08JC (located North of the seasonal upwelling region on the Cocos Ridge). During the Late Holocene, the Cocos Ridge exhibited warmer TEX86H temperatures as compared to the Carnegie Ridge. The TEX86H calculated temperatures are within analytical error of both modern annual sea surface temperatures at each site and Mg/Ca-based SST estimates derived from Globigerinoides ruber. From 5.6 kyr to 8.5 kyr there is an abrupt ~3°C decrease in the TEX86H temperatures at the Cocos Ridge, marking a breakdown in the N-S temperature gradient. Then, similar TEX86H temperatures are calculated through the Early Holocene and into the deglacial as both sites cool into the Last Glacial Maximum (LGM). Interestingly, the temperature gradient switches during the LGM, with the Carnegie Ridge yielding temperatures 1-2°C warmer than the Cocos Ridge. This gradient reversal, in contrast, is not seen in the limited Mg/Ca temperatures measured during the LGM in the same core intervals. Instead, the calculated TEX86H temperatures from both sites are cooler than calculated Mg/Ca-SSTs from the near-surface dwelling planktonic foraminifera G. ruber. Additional foraminiferal Mg/Ca and stable isotope analyses will also be presented in an effort to better constrain deglacial changes in upper water column hydrography at both sites.

  5. Petrology and geochemistry of the San Félix-San Ambrosio islands, Eastern Pacific

    Science.gov (United States)

    Cooper Percker, Oliver; Lara, Luis E.

    2015-04-01

    The San Félix-San Ambrosio (SF-SA) islands, Eastern Pacific, are fragments of two volcanic sequences 20 km apart. Both represent the top of an eroded large shield-volcano which rises over the Nazca Plate. Here, new geochemical and 40Ar/39Ar geochronological data are presented in order to understand magmatic evolution and source features. Two units are recognized on the SF island: (1) the Cerro Amarillo unit (CAU) (190±30 ka) formed by a hyaloclastic-tuff cone and basanitic lavas (Ba/Yb=519; Ba/Zr=2.19; La/Yb=49.88; Nb/Ta=17.96; Nb/Y=3.78; Nb/Zr=0.25) with absent or scarce modal content of plagioclase (20%). The hyaloclastic-tuff cone of the CAU contains aphanitic-trachytic lithic fragments of Na-augite and kaersutite, which correspond to the final product of fractional crystallization of olivine+clinopyroxene+Fe-Ti oxides+apatite±plagioclase from alkaline primitive liquids similar to SF-SA lavas. The geochemical data suggest that the islands represent different evolutive stages of a same volcanic intraplate complex. The alkaline to transitional SA lavas (Ba/Yb=249; Ba/Zr=1.60; La/Yb=24.62; Nb/Ta=16.55; Nb/Y=2.22; Nb/Zr=0.19) would represent the shield stage (ca 2.9 Ma), while the basanitic SF lavas the post-erosional stage (ca 0.2 Ma). Considering the Sr-Nd-Pb isotopic data of the SF-SA lavas, previous works have ruled out a genetic relationship between SF-SA islands and the nearby Nazca Ridge. An heterogeneous mantle plume with mantelic metasomatized recycled lithologies is hypothesized as a possible magmatic source capable of explaining the petrologic differences between the SF-SA islands and between the CAU and PU, in SF island. This research is supported by FONDECYT Project 1141303.

  6. Ocean Colour Radiometry across the Southern Atlantic and South-Eastern Pacific

    Science.gov (United States)

    Rudorff, N. D.; Kampel, M.; Frouin, R. J.

    2011-12-01

    An oceanographic cruise across the Southern Atlantic and South-eastern Pacific was undertaken from February 20th to March 14th, 2011, on board the R/V Melville (MV1102). The research vessel crossed highly dynamic regions with important roles on regional and global biogeochemical cycles, such as: the Benguela Upwelling System, the Subtropical Convergence Zone, the Patagonian Shelf, the Magellan Strait, and the Chilean Eastern Boundary Upwelling Zone. The Southern Ocean has been focus of many ocean colour studies due to the high spatio-temporal variability of bio-optical constituents and its biogeochemical importance. Nevertheless, the high latitudes and rough seas of the Southern Ocean are a great challenge for the estimation of these properties from in situ and satellite sensors. The present work shows the first results of the MV1102 cruise with the aim to access the magnitude and possible sources of errors for the estimation of in situ above water remote sensing reflectance (Rrs). Simultaneous measurements were taken at 18 stations with two hyperspectral radiometers: the Fieldspec HandHeld ASD Inc. (350-1100nm) for above water measurements, and the HyperOCR II Satlantic Inc. (380-800 nm) for in-water profiles. Above water measurements were performed with a sensor viewing geometry of 45o zenith and 137o azimuth solar angles, and the downwelling solar irradiance (ED) was estimated using a white Spectralon plaque. The Rrs was estimated with an average of 10 casts per station, and different sky reflectance factors were used to adjust to environmental conditions. Two methods were used to retrieve the Rrs: M01, without the residual sky correction (RSC); and M02, with the RSC, subtracting the Rrs at 870 nm, as a white spectral offset. The M02 was applied for all stations except in the Magellan Strait (coastal waters). For the profiler, the above water Rrs was estimated using two methods: MP01, with the ED measured from the profiler; and MP02, with ED measured from the

  7. New records of sabellids and serpulids (Polychaeta: Sabellidae, Serpulidae) from the Tropical Eastern Pacific

    DEFF Research Database (Denmark)

    Rolando Bastida-Zavala, J.; Rodriguez Buelna, Alondra Sofia; Angel De Leon-Gonzalez, Jesus

    2016-01-01

    in the large expanse of the central and southern Mexican Pacific. Thus, sabellids and serpulids were collected from several shallow water habitats along the coast of Mexican Pacific, such as coastal lagoons, coral reefs, rocky shores and from man-made structures as marinas, piers and ships of several harbors...

  8. Late Eocene diatomite from the Peruvian coastal desert, coastal upwelling in the eastern Pacific, and Pacific circulation before the terminal Eocene event

    Energy Technology Data Exchange (ETDEWEB)

    Marty, R.; Dunbar, R.; Martin, J.B.; Baker, P.

    1988-09-01

    Previously undocumented late Eocene diatomaceous sediments are present near Fundo Desbarrancado (FD) in southern Peru. These sediments are similar to Miocene diatomite from the same area but, unlike the Miocene diatomite, the FD sediments contain cherty layers, are enriched in CaCO/sub 3/, have a diverse and abundant radiolarian fauna, and possess varved-massive and millimeter- and meter-scale biogenic-terrigenous alternations. The FD sediments are part of an Eocene sequence that includes the clastic sediments of the Paracas Formation, and they are correlative to the Chira Formation of northern Peru. The Paleogene biogenic sediments of western South America show that coastal upwelling developed in the eastern Pacific before the latest Eocene, argue for the existence of a proto-Humboldt current at this time, and suggest that the terminal Eocene event was the culmination of gradual changes and not a catastrophic event at the Eocene/Oligocene boundary.

  9. Drought reconstruction in eastern Hulun Buir steppe, China and its linkages to the sea surface temperatures in the Pacific Ocean

    Science.gov (United States)

    Liu, Na; Liu, Yu; Bao, Guang; Bao, Ming; Wang, Yanchao; Zhang, Lizhi; Ge, Yuxiang; Bao, Wurigen; Tian, Heng

    2016-01-01

    A tree-ring width chronology covering the period 1780-2013 AD was developed from Pinus sylvestris var. mongolica for the eastern Hulun Buir steppe, a region located on the edge of the eastern Mongolian Plateau, China. Climate-growth response analysis revealed drought stress to be the primary limiting factor for tree growth. Therefore, the mean February-July standardized precipitation evapotranspiration index (SPEI) was reconstructed over the period 1819-2013, where the reconstruction could account for 32.8% of the variance in the instrumental record over the calibration period 1953-2011. Comparison with other tree-ring-based moisture sequences from nearby areas confirmed a high degree of confidence in our reconstruction. Severe drought intervals since the late 1970s in our study area consisted with the weakening East Asian summer monsoon, which modulating regional moisture conditions in semi-arid zone over northern China. Drought variations in the study area significantly correlated with sea surface temperatures (SSTs) in North Pacific Ocean, suggesting a possible connection of regional hydroclimatic variations to the Pacific Decadal Oscillation (PDO). The potential influence associated with El Niño-Southern Oscillation (ENSO) was primarily analyzed.

  10. Resurrection of the name Albula pacifica (Beebe, 1942 for the shafted bonefish (Albuliformes: Albulidae from the eastern Pacific

    Directory of Open Access Journals (Sweden)

    Edward Pfeiler

    2008-06-01

    Full Text Available The name Albula nemoptera (Fowler, 1911 is currently applied to the Shafted, or Threadfin, Bonefish (Albuliformes: Albulidae inhabiting the tropical coastal waters of both the western Atlantic and eastern Pacific. In the present paper I provide a brief review of the taxonomy and nomenclature of A. nemoptera, and argue that the available morphological, biogeographical and molecular evidence supports resurrecting the name A. pacifica (Beebe, 1942 for the population of A. nemoptera from the eastern Pacific. Rev. Biol. Trop. 56 (2: 839-844. Epub 2008 June 30.El nombre Albula nemoptera (Fowler, 1911 se aplica actualmente a las poblaciones del macabí de hebra (Albuliformes: Albulidae de las aguas costeras tropicales del Atlántico Occidental y el Pacifico Oriental. En este artículo se presenta una revisión breve de la taxonomía y nomenclatura de A. nemoptera, y se sugiere que la evidencia morfológica, biogeográfica y molecular apoya el reestablecimiento del nombre A. pacifica (Beebe, 1942 para la población de A. nemoptera del Pacifico Oriental.

  11. Growth and mortality rates of yellowfin tuna, Thunnus albacares (Perciformes: Scombridae, in the eastern and central Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Guoping Zhu

    2011-04-01

    Full Text Available Age and growth parameters were estimated for the yellowfin tuna Thunnus albacares (Bonnaterre, 1788. Atotal of 443 individuals were sampled from China longline fisheries in the eastern and central Pacific Ocean from February to November 2006. The von Bertalanffy growth parameters were estimated at L∞ = 175.9 cm fork length, k = 0.52 year-1, and t0 = 0.19 year. The total mortality rate (Z was estimated to be from 1.19 to 1.93 year-1, the fishing mortality (F and the natural mortality (M were calculated to be 0.91 year-1 and 0.65 year-1, respectively. The rate of exploitation (U was estimated to be 0.46. This study provides estimates of growth and mortality rate for yellowfin tuna in the eastern and central Pacific Ocean, which may be used as biological input parameters in future stock assessments for the oceanic region. However, age analysis with other techniques, additional validation of the size composition and stock structure are also needed.

  12. Epipelagic copepod distributions in the eastern equatorial Pacific during the weak La Niña event of 2001

    Directory of Open Access Journals (Sweden)

    Pritha Tutasi

    2011-07-01

    Full Text Available We determined the distribution and abundance of pelagic copepods in the eastern equatorial Pacific between the coast of Ecuador and the Galapagos Islands under oceanographic conditions associated with the weak La Niña event of 2001. In September-October 2001, negative anomalies of sea surface temperature from this event still remained in the eastern equatorial Pacific, mainly between Ecuador and the Galapagos Islands. The event allowed the incursion of the Humboldt Current farther north and of the Equatorial Undercurrent into the study area, favouring a strong Equatorial Front and upwelling processes. There was evidence of mesoscale eddies in the study area and of the presence of the South Equatorial Current going westward at about 1°N. We identified 107 copepod species and analyzed the distribution of the 10 most abundant ones: Oncaea venusta, Subeucalanus pileatus, S. crassus, S. subtenuis, Paraeucalanus attenuatus, Pleuromamma borealis, Scolecithrix danae, Clausocalanus farrani, Temora discaudata and Calanus chilensis. Copepod distribution and abundance exhibited marked latitudinal differences related to the oceanographic conditions; abundance was highest to the southeast of the Galapagos Islands. Oncaea venusta, Pleuromamma borealis, Calanus chilensis, and Subeucalanus subtenuis were the species that best defined the Equatorial Front and the upwelling process.

  13. A Review of the Systematics of Angel Sharks Emphasizing the Species of the Eastern Pacific Region with a Modified Set of Morphometrics for Order Squatiniformes

    OpenAIRE

    Alioto, Dominic

    2012-01-01

    Members of the monofamilial chondrichthyan order Squatiniformes, commonly known as angel sharks, sand devils, ange de mer, and angelotes, are primarily benthic dwelling sharks found mainly in temperate and sub-tropical parts of the Atlantic and Pacific Oceans. Squatiniformes are very easily recognized from other shark-like fishes, but the individual species within the order are much more difficult to distinguish from each other. In the eastern North Pacific (ENP) region, three species descrip...

  14. An Indo-West Pacific `zooxanthella' invasive to the western Atlantic finds its way to the Eastern Pacific via an introduced Caribbean coral

    Science.gov (United States)

    LaJeunesse, Todd C.; Forsman, Zac H.; Wham, Drew C.

    2016-06-01

    Phylogenetic evidence indicates that Siderastrea glynni, a species of coral thought to be endemic to the Eastern Pacific, is actually more likely to be Si. siderea introduced from the Atlantic. Our analyses of the endosymbionts of Si. glynni ( Symbiodinium) substantiate this as an introduced species; attempts to conserve and list Si. glynni as an endangered species are probably unwarranted. The specimens we examined harbored Symbiodinium trenchii and some also contained Sy. goreaui, symbionts that occur with Si. siderea in the Atlantic. Moreover, the genotype of Sy. trenchii (a single strain defined by ten diallelic microsatellite loci) was genetically distinct from genotypes of Sy. ` glynni,' also in Clade D, found abundantly in colonies of Pocillopora throughout the region. Furthermore, the strain of Sy. trenchii grouped with genotypes from the Greater Caribbean, an inbred population that was recently introduced from the Indo-West Pacific. This secondary introduction suggests that strains of Caribbean Sy. trenchii are capable of dispersal into new reef coral communities where this symbiont does not presently exist.

  15. Iron-binding Ligands in the Eastern Tropical South Pacific: Results from U.S. GEOTRACES Cruise GP16

    Science.gov (United States)

    Buck, K. N.; Fitzsimmons, J. N.; Sherrell, R. M.; Sohst, B. M.; Sedwick, P.; John, S.

    2016-02-01

    High-resolution depth profiles, consisting of 25-49 samples each, were collected as part of the U.S. GEOTRACES Eastern Pacific Zonal Transect (GEOTRACES cruise GP16). The organic complexation of dissolved iron in these samples, including the concentrations and conditional stability constants of iron-binding ligands, was measured by competitive ligand exchange-adsorptive cathodic stripping voltammetry using the added competitive ligand salicylaldoxime. In addition to the conventional depth profile samples for dissolved (<0.2 µm) iron-binding ligands, samples were collected for size-fractionated ligand analyses using cross flow filtration. These samples were obtained from in and around the mid-depth near-field to distal hydrothermal plume emanating from the East Pacific Rise, and allowed for iron-binding ligand analyses in the dissolved (<0.45 µm), colloidal (10 kDa to 0.45 µm) and soluble (<10 kDa) size fractions. Results from this work will be presented in the context of the few previous studies of iron-binding ligands in the South Pacific, and compared with results from the North U.S. GEOTRACES North Atlantic Transect (GEOTRACES cruise GA03).

  16. A new Lepeophtheirus (Copepoda: Siphonostomatoida: Caligidae from Isla del Coco National Park, Costa Rica, Eastern Tropical Pacific

    Directory of Open Access Journals (Sweden)

    Eduardo Suárez-Morales

    2012-11-01

    Full Text Available Among the several groups of copepods that are teleost parasites, the siphonostomatoid family Caligidae is by far the most widespread and diverse. With more than 108 nominal species, the caligid genus Lepeophtheirus von Nordmann is one of the most speciose. There are no reports of this genus in Costa Rican waters. A new species of Lepeophtheirus is herein described based on female specimens collected from plankton samples in waters off Bahía Wafer, isla del Coco, an oceanic island in the Eastern Tropical Pacific. The new species, L. alvaroi sp. nov., has some affinities with other congeners bearing a relatively short abdomen, a wider than long genital complex and a 3-segmented exopod of leg 4. it differs from most of these species by the presence of an unbranched maxillular process and by the relative lengths of the terminal claws of leg 4, with two equally long elements. it is most closely related to two other Eastern Pacific species: L. dissimulatus Wilson, 1905 and L. clarionensis Shiino, 1959. it differs from these species by the proportions and shape of the genital complex, the shape of the sternal furca, the relative length of the maxillar segments, the absence of a pectiniform process on the distal maxillar segment, the length of leg 4 and the armature of leg 5. The new species represents the first Lepeophtheirus described from Costa Rican waters of the Pacific. The low diversity of this genus in this tropi- cal region is explained by its tendency to prefer hosts from temperate latitudes. Until further evidence is found, the host of this Lepeophtheirus species remains unknown.

  17. Relationships between the surface concentration of particulate organic carbon and optical properties in the eastern South Pacific and eastern Atlantic Oceans

    Directory of Open Access Journals (Sweden)

    D. Stramski

    2007-10-01

    Full Text Available We have examined several approaches for estimating the surface concentration of particulate organic carbon, POC, from optical measurements of remote-sensing reflectance, Rrs, using field data collected in tropical and subtropical waters of the eastern South Pacific and eastern Atlantic Oceans. These approaches include a direct empirical relationship between POC and the blue-to-green band ratio of reflectance, RrsB/Rrs(555, and two-step algorithms that consist of relationships linking reflectance to an inherent optical property IOP (beam attenuation or backscattering coefficient and POC to the IOP. We considered two-step empirical algorithms that exclusively include pairs of empirical relationships and two-step hybrid algorithms that consist of semianalytical models and empirical relationships. The surface POC in our data set ranges from about 10 mg m-3 within the South Pacific Subtropical Gyre to 270 mg m-3 in the Chilean upwelling area, and data on phytoplankton pigments, suspended particulate matter, and the backscattering ratio suggest a considerable variation in the composition of particulate assemblages in the investigated waters. The POC algorithm based on the direct relationship between POC and RrsB/Rrs(555 promises reasonably good performance in the vast areas of the open ocean covering different provinces from hyperoligotrophic and oligotrophic waters within subtropical gyres to eutrophic coastal upwelling regimes characteristic of eastern ocean boundaries. The best error statistics were found for power function fits to the data of POC vs. Rrs(443/Rrs(555 and POC vs. Rrs(490/Rrs(555. For our data set that includes over 50 data pairs, these relationships are characterized by the mean normalized bias of about 2% and the normalized root mean

  18. Relationships between the surface concentration of particulate organic carbon and optical properties in the eastern South Pacific and eastern Atlantic Oceans

    Directory of Open Access Journals (Sweden)

    D. Stramski

    2008-02-01

    Full Text Available We have examined several approaches for estimating the surface concentration of particulate organic carbon, POC, from optical measurements of spectral remote-sensing reflectance, Rrs(λ, using field data collected in tropical and subtropical waters of the eastern South Pacific and eastern Atlantic Oceans. These approaches include a direct empirical relationship between POC and the blue-to-green band ratio of reflectance, RrsB/Rrs(555, and two-step algorithms that consist of relationships linking reflectance to an inherent optical property IOP (beam attenuation or backscattering coefficient and POC to the IOP. We considered two-step empirical algorithms that exclusively include pairs of empirical relationships and two-step hybrid algorithms that consist of semianalytical models and empirical relationships. The surface POC in our data set ranges from about 10 mg m−3 within the South Pacific Subtropical Gyre to 270 mg m−3 in the Chilean upwelling area, and ancillary data suggest a considerable variation in the characteristics of particulate assemblages in the investigated waters. The POC algorithm based on the direct relationship between POC and RrsB/Rrs(555 promises reasonably good performance in the vast areas of the open ocean covering different provinces from hyperoligotrophic and oligotrophic waters within subtropical gyres to eutrophic coastal upwelling regimes characteristic of eastern ocean boundaries. The best error statistics were found for power function fits to the data of POC vs. Rrs(443/Rrs(555 and POC vs. Rrs(490/Rrs(555. For our data set that includes over 50 data pairs, these relationships are characterized by the mean normalized bias of about 2% and the normalized root mean square error of about 20%. We

  19. Biochemical and volatile organic compound profile of European flat oyster (Ostrea edulis) and Pacific cupped oyster (Crassostrea gigas) cultivated in the Eastern Scheldt and Lake Grevelingen, the Netherlands

    NARCIS (Netherlands)

    Houcke, van Jasper; Medina, Isabel; Linssen, Jozef; Luten, Joop

    2016-01-01

    The aim of this study was to evaluate the effect of two important different geographical cultivation areas in the Netherlands (Eastern Scheldt and Lake Grevelingen) on the volatile organic compound (VOC) profile of European flat oyster (Ostrea edulis) and Pacific cupped oyster (Crassostrea gigas)

  20. Possible Ballast Water Transfer of Lionfish to the Eastern Pacific Ocean

    OpenAIRE

    MacIsaac, Hugh J.; De Roy, Emma M.; Leung, Brian; Grgicak-Mannion, Alice; Ruiz, Gregory M.

    2016-01-01

    The Indo-Pacific Red Lionfish was first reported off the Florida coast in 1985, following which it has spread across much of the SE USA, Gulf of Mexico, and Caribbean Sea. Lionfish negatively impact fish and invertebrate assemblages and abundances, thus further spread is cause for concern. To date, the fish has not been reported on the Pacific coast of North or Central America. Here we examine the possibility of ballast water transfer of lionfish from colonized areas in the Atlantic Ocean to ...

  1. Fish sharing as a risk factor for Opisthorchis viverrini infection: evidence from two villages in north-eastern Thailand.

    Science.gov (United States)

    Saenna, Parichat; Hurst, Cameron; Echaubard, Pierre; Wilcox, Bruce A; Sripa, Banchob

    2017-04-04

    Foodborne trematodiasis (FBT) is a significant global health problem, with the liver flukes Opisthorchis viverrini, O. felineus, and Clonorchis sinensis contributing to half of the global burden of FBT. North-eastern Thailand where O. viverrini is endemic and un-cooked fish dishes remain an integral part of the food culture has the highest reported incidence of opisthorchiasis, including associated cholangiocarcinoma. Both food sharing and eating practices are potentially important factors in FTB, suggesting an important role for the social ecology of disease transmission in these rural communities. Two rural Thai-Lao villages that were part of a 12-village project in Northeastern Thailand were selected for detailed investigation of O. viverrini infection risk associated with sharing of raw fish dishes among households. The project included screening individuals for infection and cholangiocarcinoma, a household questionnaire, and offering treatment options for positive individuals. Social network mapping was used to construct raw fish dish-sharing networks and create a proxy variable capturing variability in the degree of food sharing (DFS), measured as the number of different households with which each household shared fish dishes. Measures of associations between DFS, O. viverrini infection, the frequency of raw fish consumption, and the number of raw fish dishes consumed were generated using binary logistic regression, proportional odds ordinal logistic regression, and Poisson regression. The results showed that the probability that a household has members infected with O. viverrini increased by ~7% (P sharing is a traditional practice supporting social cohesion, food sharing network mapping should be incorporated into community-based interventions. These should encourage fish dish preparation methods that minimize infection risk by targeting households with high DFS values.

  2. Spatial and temporal variability in nutrients and carbon uptake during 2004 and 2005 in the eastern equatorial Pacific Ocean

    DEFF Research Database (Denmark)

    Palacz, A. P.; Chai, F.

    2012-01-01

    The Eastern Equatorial Pacific plays a great role in the global carbon budget due to its enhanced biological productivity linked to the equatorial upwelling. However, as confirmed by the Equatorial Biocomplexity cruises in 2004 and 2005, nutrient upwelling supply varies strongly, also due......-temporal variability in primary productivity. We demonstrate for the first time that Tropical Instability Waves can be directly linked to increased NO3 and Si(OH)4 upwelling supply and enhanced nutrient and carbon uptake, in particular by large phytoplankton such as diatoms. In order to fully...... to the Tropical Instability Waves. The aim of this study is to examine patterns of spatial and temporal variability in the biological uptake of NO3, Si(OH)4 and carbon in this region, and to evaluate the role of biological and physical interactions controlling these processes over seasonal...

  3. A new and presumably now extinct species of Millepora (Hydrozoa) in the eastern Pacific

    NARCIS (Netherlands)

    Weerdt, de W.H.; Glynn, P.W.

    1991-01-01

    A new species of hydrocoral, Millepora boschmai, is described from the Gulf of Chiriqui, Pacific Panamá. This species was first found in the early 1970's, but it has disappeared from this area as a result of the severe 1982-83 El Nino-Southern Oscillation (ENSO) event. Because the species has never

  4. Tropical Cyclone Wind Probability Forecasting for the Eastern North Pacific (EPWINDP).

    Science.gov (United States)

    1982-04-01

    OFFICER DIRECTOR CHAIRMAN ATTN: WEATHER SERVICE OFFICE CENTRAL PACIFIC HURRICANE CEN. DLPI. 0F METEOROLOGY MARINE CORPS AIR STATION NWS, NOAA CALIfOrNIA...INSTITUTO DE GEOFISICA DIRECTOR HONOLULU, HI 96822 U.N.A.M. BIBLIOTECA NATIONAL HURRICANE CENTER TORRE DE CIENCIAS, 3ER PISO NOAA, GABLES ONE TOWER CHAIRMAN

  5. Fe, Zn, and Cd stable isotopes from the eastern tropical South Pacific from GEOTRACES cruise GP16 - Methods and data

    Science.gov (United States)

    Helgoe, J. M.; Townsend, E.; John, S.

    2014-12-01

    A new method has been developed for the rapid analysis of metal concentrations and stable isotope ratios using a prepFAST automated sample processing robot. Although concentrations and isotopes are processed separately, similar methods are used for both. Initially all seawater is acidified to pH 2. Then Nobias resin with EDTA/IDA functional groups is added to either 10mL of sample for concentrations or ~1L samples for isotopes. Fe binds to the resin at low pH, and the pH is subsequently raised to allow Zn and Cd to bind. For concentration analyses, all subsequent chemistry is automated on the prepFAST including removal of seawater, rinsing of resin, and elution of resin into acid. For isotope samples these extraction techniques are performed manually, but the subsequent purification of Fe, Zn, and Cd by anion exchange chromatography is automated using the prepFAST. With these new methods, samples from the US GEOTRACES cruise GP16, in the eastern tropical South Pacific, are being analyzed. High concentrations of dissolved Fe are observed near the continental shelf and near submarine hydrothermal vents. Interestingly, isotope data show that dissolved Fe near the continental shelf generally has a δ56Fe close to 0 ‰. This δ56 Fe signature is suggestive of a non-reductive dissolution source for Fe, as Fe(II) released by reductive dissolution is typically closer to -2 ‰. Preliminary data show nutrient-type profiles for Zn and Cd, with Zn matching Si and Cd having a similar distribution to P. An increase in dissolved Zn near hydrothermal vents suggests a possible hydrothermal zinc source to the deep ocean. Continuing analysis of isotope data will reveal more about the source and biogeochemical cycling of these three chemically and biologically important trace metals throughout the eastern tropical Pacific Ocean.

  6. Annual egg production rates of calanoid copepod species on the continental shelf of the Eastern Tropical Pacific off Mexico

    Science.gov (United States)

    Kozak, Eva R.; Franco-Gordo, Carmen; Palomares-García, Ricardo; Gómez-Gutiérrez, Jaime; Suárez-Morales, Eduardo

    2017-01-01

    We provide the first estimations of calanoid copepod egg production rates (EPR) in the Eastern Tropical Pacific over an annual cycle (January-December 2011). Gravid females were collected twice monthly and incubated for 12 h without food to estimate EPR, weight-specific fecundity (Gf), spawning success (SS, percentage of females to spawn out of the total species incubated per month and season) and egg hatching success (EHS). This study reports the average EPR of 10 species and the monthly EPR and Gf of four planktonic calanoid copepods (Centropages furcatus, Temora discaudata, Pontellina sobrina, and Nannocalanus minor) that spawned with enough frequency to infer their seasonal reproductive patterns. These species showed distinct seasonal reproductive strategies. Most copepod species spawned sporadically with large EPR variability, while three copepod species reproduced throughout the year (C. furcatus, T. discaudata and P. sobrina) and N. minor spawned only during the mixed period (Feb-May). The four species had relatively similar average EPR (C. furcatus 16, T. discaudata 18, P. sobrina 13, and N. minor 12 eggs fem-1 day-1). These are the first EPR estimations of P. sobrina and its previously known reproductive period is expanded. A Canonical Correspondence Analysis (CCA) was used to analyze EPR and species abundance of all calanoid copepods (40 spp.) collected throughout the time series in relation to temperature, salinity, mixed layer depth (MLD), dissolved oxygen, and chlorophyll a (Chl-a) concentrations to identify the variables that best explained the copepod abundance variability. Temperature, Chl-a, and salinity had the strongest effect on the biological variables, linked to seasonal and episodic upwelling-downwelling processes in the surveyed area. As a result of moderate upwelling events and seasonal variation of environmental conditions, it appears relatively few species are capable of maintaining continuous reproduction under the relatively higher

  7. Phylogenetic Characterization of Marine Benthic Archaea in Organic-Poor Sediments of the Eastern Equatorial Pacific Ocean (ODP Site 1225).

    Science.gov (United States)

    Lauer, Antje; Sørensen, Ketil Bernt; Teske, Andreas

    2016-09-06

    Sequencing surveys of microbial communities in marine subsurface sediments have focused on organic-rich, continental margins; the database for organic-lean deep-sea sediments from mid-ocean regions is underdeveloped. The archaeal community in subsurface sediments of ODP Site 1225 in the eastern equatorial Pacific (3760 m water depth; 1.1 and 7.8 m sediment depth) was analyzed by PCR, cloning and sequencing, and by denaturant gradient gel electrophoresis (DGGE) of 16S rRNA genes. Three uncultured archaeal lineages with different depth distributions were found: Marine Group I (MG-I) within the Thaumarchaeota, its sister lineage Marine Benthic Group A (MBG-A), the phylum-level archaeal lineage Marine Benthic Group B (also known as Deep-Sea Archaeal Group or Lokiarchaeota), and the Deep-Sea Euryarchaeotal Group 3. The MG-I phylotypes included representatives of sediment clusters that are distinct from the pelagic members of this phylum. On the scale from fully oxidized, extremely organic carbon-depleted sediments (for example, those the South Pacific Gyre) to fully reduced, organic carbon-rich marine subsurface sediments (such as those of the Peru Margin), Ocean Drilling Program (ODP) Site 1225 falls into the non-extreme organic carbon-lean category, and harbors archaeal communities from both ends of the spectrum.

  8. Acoustic detections of singing humpback whales (Megaptera novaeangliae) in the eastern North Pacific during their northbound migration.

    Science.gov (United States)

    Norris, T F; McDonald, M; Barlow, J

    1999-07-01

    Numerous (84) acoustic detections of singing humpback whales were made during a spring (08 March-09 June 1997) research cruise to study sperm whales in the central and eastern North Pacific. Over 15,000 km of track-line was surveyed acoustically using a towed hydrophone array. Additionally, 83 sonobuoys were deployed throughout the study area. Detection rates were greatest in late March, near the Hawaiian Islands, and in early April, northeast of the islands. Only one detection was made after April. Detection rates for sonobuoys were unequal in three equally divided longitudinal regions of the study area. Two high density clusters of detections occurred approximately 1200-2000 km northeast of the Hawaiian Islands and were attributed to a large aggregation of migrating animals. The distribution of these detections corroborates findings of previous studies. It is possible that these animals were maintaining acoustic contact during migration. Two unexpected clusters of singing whales were detected approximately 900 to 1000 km west of central and southern California. The location of these detections may indicate a previously undocumented migration route between an offshore breeding area, such as the Revillagigedo Islands, Mexico, and possible feeding areas in the western North Pacific or Bering Sea.

  9. Evidence of Enhanced Respired Carbon in Eastern Equatorial Pacific Deep-Waters over the last 30,000 years

    Science.gov (United States)

    Umling, N. E.; Thunell, R.

    2016-12-01

    Rapid decreases in glacial deep water reservoir ages have been observed in the Eastern Equatorial Pacific (EEP; this study), North Pacific (Rae et al., 2014), Southwest Pacific (Sikes et al., 2016), and North Atlantic (Skinner et al., 2013). It has been hypothesized that release of a deep ocean 14C-depleted, respired-carbon reservoir to the surface ocean and atmosphere is the most likely mechanism for the observed increases in atmospheric CO2 concentrations recorded in ice cores during the last glacial-interglacial transition (Broecker and Barker, 2007). This study examines whether oxygenation, organic carbon flux, and carbonate chemistry in the EEP deep-waters reflect an increase in respired carbon associated with recorded 14C-depletions using isotopic and trace element records from three Panama Basin cores (2,650-3,200 m water-depth). An increase in glacial deep-water respired carbon storage would result in a shift of DIC speciation towards lower carbonate ion concentrations along with deoxygenation of bottom waters. Specifically, we use the boron to calcium (B/Ca) and uranium to calcium (U/Ca) ratios of the benthic foraminifera Cibicidoides wuellerstorfi to reconstruct deep-water carbonate ion concentration (Yu and Elderfield, 2007; Raizsch et al., 2011). Additionally, bottom water oxygenation is estimated from the difference in δ13C of benthic foraminifera living in pore waters at the anoxic boundary and of those living in bottom water (Δ δ13C; Hoogakker et al., 2015, 2016), while carbon flux was assessed from the U/Ca and Cd/Ca of foraminiferal authigenic coatings.

  10. Pre-whaling genetic diversity and population ecology in eastern Pacific gray whales: insights from ancient DNA and stable isotopes.

    Directory of Open Access Journals (Sweden)

    S Elizabeth Alter

    Full Text Available Commercial whaling decimated many whale populations, including the eastern Pacific gray whale, but little is known about how population dynamics or ecology differed prior to these removals. Of particular interest is the possibility of a large population decline prior to whaling, as such a decline could explain the ~5-fold difference between genetic estimates of prior abundance and estimates based on historical records. We analyzed genetic (mitochondrial control region and isotopic information from modern and prehistoric gray whales using serial coalescent simulations and Bayesian skyline analyses to test for a pre-whaling decline and to examine prehistoric genetic diversity, population dynamics and ecology. Simulations demonstrate that significant genetic differences observed between ancient and modern samples could be caused by a large, recent population bottleneck, roughly concurrent with commercial whaling. Stable isotopes show minimal differences between modern and ancient gray whale foraging ecology. Using rejection-based Approximate Bayesian Computation, we estimate the size of the population bottleneck at its minimum abundance and the pre-bottleneck abundance. Our results agree with previous genetic studies suggesting the historical size of the eastern gray whale population was roughly three to five times its current size.

  11. Climate Prediction Center (CPC)Area-averaged 850-hPa Eastern Pacific Trade Wind Anomalies

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is one of the CPC?s Monthly Atmospheric and SST Indices. It is the 850-hPa trade wind anomalies averaged over the area 5oN ? 5oS, 135oW-120oW (eastern...

  12. Migratory preferences of humpback whales between feeding and breeding grounds in the eastern South Pacific

    NARCIS (Netherlands)

    Acevedo, Jorge; Aguayo-lobo, Anelio; Allen, Judith; Botero-acosta, Natalia; Capella, Juan; Castro, Cristina; Rosa, Luciano Dalla; Denkinger, Judith; Félix, Fernando; Flórez-gonzález, Lilian; Garita, Frank; Guzmán, Héctor M.; Haase, Ben; Kaufman, Gregory; Llano, Martha; Olavarría, Carlos; Pacheco, Aldo S.; Plana, Jordi; Rasmussen, Kristin; Scheidat, Meike; Secchi, Eduardo R.; Silva, Sebastian; Stevick, Peter T.

    2017-01-01

    Latitudinal preferences within the breeding range have been suggested for Breeding Stock G humpback whales that summer in different feeding areas of the eastern South Pacific. To address this hypothesis, humpback whales photo-identified from the Antarctic Peninsula and the Fueguian Archipelago

  13. Jostling for Position: The Future of Regional Power-Sharing and the Role of the Pacific Islands Forum

    Directory of Open Access Journals (Sweden)

    Kylie Evans-Locke

    2016-07-01

    Full Text Available The Pacific Islands Forum has long held the title of the most dominant regional association with links in trade, politics and regional security. Following two political coups in the region the PIF was forced to shift its approach to regional governance opting for a more active and hands-on role with its first such mission being the Regional Assistance Mission to Solomon Islands (RAMSI. The role undertaken by the PIF within RAMSI is noteworthy for its shifts and changes with an initially minimalist role morphed into an intermediary role as tensions rose between the major funding donor, Australia, and the host state, Solomon Islands in 2006-07. Although the PIF acted in a mediator role in this instance this has not been the normal role for the institution. This article examines the role the PIF has adopted in managing regional democratic stability through targeted development activities, whether their adopted role is applicable on a wider regional-level scale, and further, through examining key human-security related challenges, such as climate change, where the PIF fits into regional power-sharing institutions in the Pacific Islands of the future.

  14. A regional scale modeling analysis of aerosol and trace gas distributions over the eastern Pacific during the INTEX-B field campaign

    Directory of Open Access Journals (Sweden)

    B. Adhikary

    2010-03-01

    Full Text Available The Sulfur Transport and dEposition Model (STEM is applied to the analysis of observations obtained during the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B, conducted over the eastern Pacific Ocean during spring 2006. Predicted trace gas and aerosol distributions over the Pacific are presented and discussed in terms of transport and source region contributions. Trace species distributions show a strong west (high to east (low gradient, with the bulk of the pollutant transport over the central Pacific occurring between ~20° N and 50° N in the 2–6 km altitude range. These distributions are evaluated in the eastern Pacific by comparison with the NASA DC-8 and NSF/NCAR C-130 airborne measurements along with observations from the Mt. Bachelor (MBO surface site. Thirty different meteorological, trace gas and aerosol parameters are compared. In general the meteorological fields are better predicted than gas phase species, which in turn are better predicted than aerosol quantities. PAN is found to be significantly overpredicted over the eastern Pacific, which is attributed to uncertainties in the chemical reaction mechanisms used in current atmospheric chemistry models in general and to the specifically high PAN production in the SAPRC-99 mechanism used in the regional model. A systematic underprediction of the elevated sulfate layer in the eastern Pacific observed by the C-130 is another issue that is identified and discussed. Results from source region tagged CO simulations are used to estimate how the different source regions around the Pacific contribute to the trace gas species distributions. During this period the largest contributions were from China and from fires in South/Southeast and North Asia. For the C-130 flights, which operated off the coast of the Northwest US, the regional CO contributions range as follows: China (35%, South/Southeast Asia fires (35%, North America anthropogenic (20%, and North Asia fires (10

  15. Feeding ecology of elasmobranch fishes in coastal waters of the Colombian Eastern Tropical Pacific

    OpenAIRE

    Mejía-Falla Paola A; Navia Andrés F; Giraldo Alan

    2007-01-01

    Abstract Background Stomach contents of 131 specimens of five elasmobranch species (Mustelus lunulatus, Dasyatis longa, Rhinobatos leucorhynchus, Raja velezi and Zapteryx xyster) caught in the central fishing zone in the Pacific Ocean of Colombia were counted and weighed to describe feeding habits and dietary overlaps. Results Twenty-one prey items belonging to four major groups (stomatopods, decapods, mollusks and fish) were identified. Decapod crustaceans were the most abundant prey found i...

  16. PAN in the eastern Pacific free troposphere: A satellite view of the sources, seasonality, interannual variability, and timeline for trend detection

    Science.gov (United States)

    Zhu, Liye; Payne, Vivienne H.; Walker, Thomas W.; Worden, John R.; Jiang, Zhe; Kulawik, Susan S.; Fischer, Emily V.

    2017-03-01

    Peroxyacetyl nitrate (PAN) is an important trace gas that serves to transport nitrogen oxide radicals throughout the troposphere. We present an analysis of satellite observations of PAN from the Tropospheric Emission Spectrometer (TES) over the eastern Pacific Ocean for April and July 2006-2010 and the spring-to-summer seasonal transition for 2006. TES can provide quantitative estimates of free tropospheric PAN in clear-sky or thin cloud conditions where elevated PAN (>0.2 ppbv) is present. The percentage of successful PAN detections increases from April to July and then decreases in August and September. However, there are no significant differences in the tropospheric average PAN either interannually or between these months. Plumes containing elevated PAN are present almost every day in July. Elevated PAN observed in July has multiple sources, including fires in Siberia, anthropogenic sources in eastern China, and recirculated pollution from the continental U.S. We combined the observed variability in the TES PAN retrievals over the eastern Pacific Ocean with a range of possible trends in PAN to determine the observational requirements to detect such trends. Based on the variability observed in the PAN retrievals over this region, we predict that it would be faster to detect a trend of a given magnitude in PAN using satellite observations over the eastern Pacific Ocean region rather than in situ surface observations and that a trend of a given magnitude would be more quickly detected in summer than spring.

  17. The Colombia Current: An Eastern Tropical Pacific Coastal Current, Early Oceanographic Characteristics

    Science.gov (United States)

    Rodriguez-Rubio, E.

    2007-05-01

    Newly gathered hydrographic data from the Colombia Pacific Ocean is combined with remote sensing data to reassess the properties of the costal current named Colombian Current by Wooster (1959). The Colombian Pacific Ocean is located between 84°-76°W and 1°30'-5°N (oceanic zone), 1°30'- 7°N (coastal zone): This area is well-known also like Panama Bight. New hydrographic data were occupied along the Colombian Pacific coast during March of 2006, making 41 stations with measurements of CTD until a maximum depth of 1200 m, depending on the depth of the marine bottom. On the other hand, sea surface temperatures (SST) were obtained from the MODIS-AQUA satellite and sea surface wind speed and wind direction stem from QuickScat, both averaged for March 2006. Hydrographic grid layers necessary to obtain dynamic topography variable were made with objective mapping calculating is not total dynamic height, but the dynamic height between consecutive levels or "thickness". The purpose of this methodology is that in very coastal campaigns it can have a substantial number of stations that do not arrive at the reference level. Finally geostrophic velocity was computed for the Colombian Current area at several layers. The coast was characterized by low salinities due to river runoff in the North zone. The sea surface temperature during the month of March of 2006 was especially low in the oceanic zone, reaching temperatures between 19°C and 24°C.The dynamic topography indicated the presence of a surface coastal current flowing towards the north and a crosscurrent to 400 m of depth never before described. The wind corresponded to the pattern of the wind jet of Panama. During March the ITCZ moves south, drawing the Panama jet across the Isthmus and over the Pacific. Upwelling curl associated with the left (southeast) flank of this jet generates a cyclonic eddy in the Panama Bight and SST cooling in its center. In the Panama Bight, the curl dipole produces a cyclonic circulation

  18. Explained and unexplained tissue loss in corals from the Tropical Eastern Pacific

    Science.gov (United States)

    Rodriguez-Villalobos, Jenny Carolina; Work, Thierry M.; Calderon-Aguilera, Luis Eduardo; Reyes-Bonilla, Hector; Hernández, Luis

    2015-01-01

    Coral reefs rival rainforest in biodiversity, but are declining in part because of disease. Tissue loss lesions, a manifestation of disease, are present in dominant Pocillopora along the Pacific coast of Mexico. We characterized tissue loss in 7 species of Pocillopora from 9 locations (44 sites) spanning southern to northern Mexico. Corals were identified to species, and tissue loss lesions were photographed and classified as those explainable by predation and those that were unexplained. A focal predation study was done concurrently at 3 locations to confirm origin of explained lesions. Of 1054 cases of tissue loss in 7 species of corals, 84% were associated with predation (fish, snails, or seastar) and the remainder were unexplained. Types of tissue loss were not related to coral density; however there was significant geographic heterogeneity in type of lesion; one site in particular (Cabo Pulmo) had the highest prevalence of predator-induced tissue loss (mainly pufferfish predation). Crown-of-thorns starfish, pufferfish, and snails were the most common predators and preferred P. verrucosa, P. meandrina, and P. capitata, respectively. Of the 9 locations, 4 had unexplained tissue loss with prevalence ranging from 1 to 3% with no species predilection. Unexplained tissue loss was similar to white syndrome (WS) in morphology, indicating additional study is necessary to clarify the cause(s) of the lesions and the potential impacts to dominant corals along the Pacific coast of Mexico.

  19. Exceptional warming in the Western Pacific-Indian Ocean warm pool has contributed to more frequent droughts in eastern Africa

    Science.gov (United States)

    Funk, Christopher C.; Peterson, Thomas C.; Stott, Peter A.; Herring, Stephanie

    2012-01-01

    In 2011, East Africa faced a tragic food crisis that led to famine conditions in parts of Somalia and severe food shortages in parts of Ethiopia and Somalia. While many nonclimatic factors contributed to this crisis (high global food prices, political instability, and chronic poverty, among others) failed rains in both the boreal winter of 2010/11 and the boreal spring of 2011 played a critical role. The back-to-back failures of these rains, which were linked to the dominant La Niña climate and warm SSTs in the central and southeastern Indian Ocean, were particularly problematic since they followed poor rainfall during the spring and summer of 2008 and 2009. In fact, in parts of East Africa, in recent years, there has been a substantial increase in the number of below-normal rainy seasons, which may be related to the warming of the western Pacific and Indian Oceans (for more details, see Funk et al. 2008; Williams and Funk 2011; Williams et al. 2011; Lyon and DeWitt 2012). The basic argument of this work is that recent warming in the Indian–Pacific warm pool (IPWP) enhances the export of geopotential height energy from the warm pool, which tends to produce subsidence across eastern Africa and reduce onshore moisture transports. The general pattern of this disruption has been supported by canonical correlation analyzes and numerical experiments with the Community Atmosphere Model (Funk et al. 2008), diagnostic evaluations of reanalysis data (Williams and Funk 2011; Williams et al. 2011), and SST-driven experiments with ECHAM4.5, ECHAM5, and the Community Climate Model version 3 (CCM3.6) (Lyon and DeWitt 2012).

  20. Projected wave conditions in the Eastern North Pacific under the influence of two CMIP5 climate scenarios

    Science.gov (United States)

    Erikson, Li H.; Hegermiller, Christie; Barnard, Patrick; Ruggiero, Peter; van Ormondt, Martin

    2015-01-01

    Hindcast and 21st century winds, simulated by General Circulation Models (GCMs), were used to drive global- and regional-scale spectral wind-wave generation models in the Pacific Ocean Basin to assess future wave conditions along the margins of the North American west coast and Hawaiian Islands. Three-hourly winds simulated by four separate GCMs were used to generate an ensemble of wave conditions for a recent historical time-period (1976–2005) and projections for the mid and latter parts of the 21st century under two radiative forcing scenarios (RCP 4.5 and RCP 8.5), as defined by the fifth phase of the Coupled Model Inter-comparison Project (CMIP5) experiments. Comparisons of results from historical simulations with wave buoy and ERA-Interim wave reanalysis data indicate acceptable model performance of wave heights, periods, and directions, giving credence to generating projections. Mean and extreme wave heights are projected to decrease along much of the North American west coast. Extreme wave heights are projected to decrease south of ∼50°N and increase to the north, whereas extreme wave periods are projected to mostly increase. Incident wave directions associated with extreme wave heights are projected to rotate clockwise at the eastern end of the Aleutian Islands and counterclockwise offshore of Southern California. Local spatial patterns of the changing wave climate are similar under the RCP 4.5 and RCP 8.5 scenarios, but stronger magnitudes of change are projected under RCP 8.5. Findings of this study are similar to previous work using CMIP3 GCMs that indicates decreasing mean and extreme wave conditions in the Eastern North Pacific, but differ from other studies with respect to magnitude and local patterns of change. This study contributes toward a larger ensemble of global and regional climate projections needed to better assess uncertainty of potential future wave climate change, and provides model boundary conditions for assessing the impacts of

  1. On the variability of tropospheric ozone in the Tropical Eastern Pacific and its impact on the oxidizing capacity

    Science.gov (United States)

    Saiz-Lopez, A.; Gomez Martin, J.; Hay, T.; Mahajan, A.; Ordoñez, C.; Parrondo Sempere, M.; Gil, M. J.; Agama Reyes, M.; Paredes Mora, J.; Voemel, H.

    2012-12-01

    Observations of surface ozone, NOx and meteorological variables were made during two ground based field campaigns in the Eastern Pacific marine boundary layer (MBL). The first study was PIQUERO (Primera Investigación de la Química, Evolución y Reparto de Ozono), running from September 2000 to July 2001 in parallel to the Southern Hemisphere ADditional OZonesondes (SHADOZ) in the Galápagos Islands. The second study is the Climate and HAlogen Reactivity tropicaL EXperiment (CHARLEX), running from September 2010 to present. These long-term, high frequency, measurements enable a detailed description of the daily, monthly, seasonal and interannual variability of ozone and help to constrain the MBL and lower free troposphere (FT) ozone budget. In the Equatorial Eastern Pacific "cold season" (August - October), net ozone photochemical destruction of ~ 2 ppb day-1 occurs in the MBL (~30% due to halogens, and the rest to HOx). Ozone recovers by entrainment from aloft at night. The monthly baseline is set by the tropical instability waves (TIW), which also impact the ozone concentration in the lower FT. In the cold phase of the TIWs the MBL is stratified and, apart from higher surface ozone, it may also contain an upper drier layer with higher ozone between ~ 500 m and the main inversion at ~1 km. In the warm phase the buoyant MBL expands upwards (as much as 500 m) and poor ozone air reaches the FT. As the system shifts to the warm season (February- April), the TIWs stop and the sea becomes warmer, increasing evaporation and reducing ozone. The inversion is pushed upwards and finally disappears or becomes very weak. Surface ozone is so low that even at the low background NOx levels observed ozone production balances photochemical destruction, so the daily profile is flat (observed local effects in the populated areas of Galapagos are discussed). In February Galapagos is almost in the doldrums because the Inter-Tropical Convergence Zone (ITCZ) shifts south. In this

  2. Physical, Chemical, and Biological CTD and Bottle data from NATHANIEL B. PALMER in Eastern Tropical South Pacific Ocean near Peru/Chile from 2013-06-24 to 2013-07-22 (NCEI Accession 0128141)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report contains data from R/V Nathaniel B. Palmer cruise NBP 1305 to the eastern tropical south pacific oxygen deficient zone. The objective of the cruise was...

  3. Physical, chemical and biological CTD and bottle data from R/V Thomas G. Thompson cruise TN278 in eastern tropical North Pacific Ocean from March 19 to April 20, 2012 (NODC Accession 0109846)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This report contains data from R/V Thomas G. Thompson cruise TN278 to the eastern tropical north pacific oxygen deficient zone. The objective of the cruise was to...

  4. Shore-based counts of the Eastern North Pacific gray whale stock from central California conducted from 1967-12-18 to 2007-02-22 (NCEI Accession 0138007)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Fisheries Service (NMFS) has conducted shore-based counts of the Eastern North Pacific stock of gray whales (Eschrichtius robustus) 26 years from...

  5. Striations and preferred eddy tracks triggered by topographic steering of the background flow in the eastern South Pacific

    Science.gov (United States)

    Belmadani, Ali; Concha, Emilio; Donoso, David; Chaigneau, Alexis; Colas, François; Maximenko, Nikolai; Di Lorenzo, Emanuele

    2017-04-01

    In recent years, persistent quasi-zonal jets or striations have been ubiquitously detected in the world ocean using satellite and in situ data as well as numerical models. This study aims at determining the role of mesoscale eddies in the generation and persistence of striations off Chile in the eastern South Pacific. A 50 year climatological integration of an eddy-resolving numerical ocean model is used to assess the long-term persistence of striations. Automated eddy tracking algorithms are applied to the model outputs and altimetry data. Results reveal that striations coincide with both polarized eddy tracks and the offshore formation of new eddies in the subtropical front and coastal transition zone, without any significant decay over time that discards random eddies as a primary driver of the striations. Localized patches of vortex stretching and relative vorticity advection, alternating meridionally near the eastern edge of the subtropical front, are associated with topographic steering of the background flow in the presence of steep topography, and with baroclinically and barotropically unstable meridional flow. These sinks and sources of vorticity are suggested to generate the banded structure further west, consistently with a β-plume mechanism. On the other hand, zonal/meridional eddy advection of relative vorticity and the associated Reynolds stress covariance are consistent with eddy deformation over rough topography and participate to sustain the striations in the far field. Shear instability of mean striations is proposed to feedback onto the eddy field, acting to maintain the subtropical front eddy streets and thus the striations.

  6. Reply to Comment on 'Drought Variability in the Eastern Australia and New Zealand Summer Drought Atlas (ANZDA, CE 1500-2012) Modulated by the Interdecadal Pacific Oscillation'

    Science.gov (United States)

    Palmer, Jonathan G.; Cook, Edward R.; Turney, Chris S. M.; Allen, Kathy; Fenwick, Pavla; Cook, Benjamin I.; O'Donnell, Alison; Lough, Janice; Grierson, Pauline; Baker, Patrick J.

    2017-01-01

    This reply is in response to Vance et al (2017), who expressed concern that their Law Dome summer sea salt record (LDsss; Vance et al 2013) and two Interdecadal Pacific Oscillation (IPO) reconstructions (PLF and DT-median; Vance et al 2015) were not compared properly in our recent study (Palmer et al 2015) describing the eastern Australian and New Zealand summer Drought Atlas (ANZDA) and that this omission mischaracterizes their records.

  7. Changes in the depth habitat of the Oligocene planktic foraminifera (Dentoglobigerina venezuelana) induced by thermocline deepening in the eastern equatorial Pacific

    Science.gov (United States)

    Matsui, Hiroki; Nishi, Hiroshi; Takashima, Reishi; Kuroyanagi, Azumi; Ikehara, Minoru; Takayanagi, Hideko; Iryu, Yasufumi

    2016-06-01

    Understanding planktic foraminiferal depth habitat along with consistent taxonomic concepts is key to accurate reconstruction of paleoceanographic records. The Oligocene-Pliocene long-ranging and widely distributed species Dentoglobigerina venezuelana lived in the mixed layer (shallower) during the early Oligocene, whereas the same species calcified at thermocline or subthermocline depths (deeper) during the late Oligocene and Miocene. The exact timing of the species' depth habitat change and its possible relationships with Oligocene climate dynamics remain unknown. Here we reveal isotopic records of D. venezuelana along with the Paragloborotalia siakensis group (a mixed-layer dweller) by using sediments at Integrated Ocean Drilling Program Site U1334 in the eastern equatorial Pacific throughout the Oligocene. A two-step depth habitat change of D. venezuelana is apparent: (1) from upper to lower mixed layer (~27.4 Ma) and (2) from lower mixed layer to thermocline depth (~26.3 Ma). In addition, the planktic foraminiferal faunal assemblage experienced a marked change from dominantly thermocline (deeper) species to abundant mixed-layer (shallower) species, suggesting that depth habitat shifts of D. venezuelana were clearly related to thermocline deepening in the eastern equatorial Pacific. Comparison of the first isotopic shift (~27.4 Ma) at multiple sites (U1334, U1333, and 1218) revealed a southward depth habitat change of D. venezuelana within ~200 kyr, implying overall thermocline deepening with reduced steepness in the eastern equatorial Pacific. We consider that global warming conditions during the late Oligocene likely caused thermocline deepening with upwelling decrease in the eastern equatorial Pacific, guiding D. venezuelana to adapt to greater depths in the water column.

  8. The comparative statuses of the Far Eastern seas and the northwestern Pacific Ocean based on the range of integral characteristics of pelagic and bottom trawl macrofauna

    Directory of Open Access Journals (Sweden)

    Igor V. Volvenko

    2015-03-01

    Full Text Available Comparison of the pelagial and benthal of the Far Eastern seas (mainly within the borders of the Russian EEZ and the contiguous part of the Pacific Ocean according to the macrofauna population density, species richness, evenness and diversity, and average individual weight of animals, is provided on the basis of the results of multiannual broad-scale pelagic and bottom trawl surveys carried out in 1977–2010.

  9. Prevalence of the commensal barnacle Xenobalanus globicipitis on cetacean species in the eastern tropical Pacific Ocean, and a review of global occurrence

    OpenAIRE

    2008-01-01

    Distribution and prevalence of the phoretic barnacle Xenobalanus on cetacean species are reported for 22 cetaceans in the eastern tropical Pacific Ocean (21 million km2). Four cetacean species are newly reported hosts for Xenobalanus: Bryde’s whale (Balaenoptera edeni), long-beaked common dolphin (Delphinus capensis), humpback whale (Megaptera novaeangliae), and spinner dolphin (Stenella longirostris). Sightings of Xenobalanus in pelagic waters are reported for the first time, and concentr...

  10. Measurements of vertical distributions of bromine oxide, iodine oxide, oxygenated hydrocarbons and ozone over the Eastern Tropical Pacific Ocean

    Science.gov (United States)

    Volkamer, R. M.; Baidar, S.; Dix, B. K.; Apel, E. C.; Hornbrook, R. S.; Pierce, B.; Gao, R.

    2012-12-01

    As part of the Tropical Ocean tRoposphere Exchange of Reactive halogen species and Oxygenated VOC (TORERO) field experiment 17 research flights were conducted with the NSF/NCAR GV aircraft equipped with a combination of chemical in-situ sensors, and remote sensing instruments to characterize air-sea exchange of reactive halogen species, oxygenated hydrocarbons, and aerosols, and their transport into the free troposphere, over different ocean environments of the Humboldt current in the Eastern Tropical Pacific Ocean (42S to 14N Lat.; 70W to 105W Long.). This presentation presents measurements of the spatial distributions of halogen oxide radicals, oxygenated hydrocarbons, and discusses their impact on ozone destruction rates, and the oxidation of atmospheric mercury. Air mass history is assessed by means of the Real-time Air Quality Modeling System (RAQMS), a global meteorological, chemical and aerosol assimilation/forecasting system that assimilates real-time stratospheric ozone retrievals from the Microwave Limb Sounder (MLS), total column ozone from the Ozone Monitoring Instrument (OMI), and aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS). Reactive halogen species and organic carbon are important in the atmosphere, because they modify HOx radical abundances, influence the reactive chemistry and lifetime of climate active gases (e.g., ozone, methane, dimethyl sulfide), modify aerosol-cloud interactions; halogen radicals can further oxidize atmospheric mercury.

  11. Role of circulation scales and water mass distributions on larval fish habitats in the Eastern Tropical Pacific off Mexico

    Science.gov (United States)

    León-Chávez, Cristina A.; Beier, Emilio; Sánchez-Velasco, Laura; Barton, Eric Desmond; Godínez, Victor M.

    2015-06-01

    On the basis of five oceanographic cruises carried out in the Eastern Tropical Pacific off Mexico, relationships between the larval fish habitats (areas inhabited by larval fish assemblages) and the environmental circulation scales (mesoscale, seasonal, and interannual) were examined. Analysis of in situ data over a grid of hydrographic stations and oblique zooplankton hauls with bongo net (505 µm) was combined with orthogonal robust functions decomposition applied to altimetry anomalies obtained from satellite. During both cool (March and June) and warm (August and November) periods, Bray-Curtis dissimilarity Index defined three recurrent larval fish habitats which varied in species composition and extent as a function of the environmental scales. The variability of the Tropical larval fish habitat (characterized by high species richness, and dominated by Vinciguerria lucetia, Diogenichthys laternatus, and Diaphus pacificus) was associated with the seasonal changes. The Transitional-California Current larval fish habitat (dominated by V. lucetia and D. laternatus, with lower mean abundance and lower species richness than in the Tropical habitat) and Coastal-and-Upwelling larval fish habitat (dominated by Bregmaceros bathymaster) was associated mainly with mesoscale activity induced by eddies and with coastal upwelling. During February 2010, the Tropical larval fish habitat predominated offshore and the Transitional-California Current larval fish habitat was not present, which we attribute to the effect of El Niño conditions. Thus, the mesoscale, seasonal, and interannual environmental scales affect the composition and extension of larval fish habitats.

  12. Gross and microscopic pathology of lesions in Pocillopora spp. from the subtropical eastern Pacific

    Science.gov (United States)

    Rodríguez-Villalobos, Jenny Carolina; Rocha-Olivares, Axayácatl; Work, Thierry Martin; Calderon-Aguilera, Luis Eduardo; Cáceres-Martínez, Jorge Abelardo

    2014-01-01

    Coral reefs are threatened by a variety of factors including diseases that have caused significant damage in some regions such as in the Caribbean. At present, no data are available on coral diseases in the Mexican Pacific where Pocillopora spp. is a dominant component of coral communities. Here, we describe gross and microscopic morphology of lesions found in pocilloporids at four sites in the Mexican Pacific. Corals were identified and their lesions photographed and quantified in the field. Tissue samples were collected from healthy and affected colonies for histopathology. We recorded seven species of pocilloporids at the study sites with Isla Isabel being the location with the highest coral diversity (H′ = 1.27). Lesions were present in 42% of the colonies and included discoloration (32%), predation-induced tissue loss (30%), unexplained tissue loss (3%) and overgrowth by sponges or algae (35%). The most affected species, P. damicornis (50%), was also one of the most common in the region. No species was more prone to a particular lesion, but there was a significant association between location and the presence of lesions. Northern Islas Marietas (61%) and Isla Isabel (41%) had the highest prevalence of lesions, followed by Manzanillo (37%) and Bahías de Huatulco (23%). Histological changes included atrophy of the surface body wall with depletion of zooxanthellae (91%) in corals with discoloration (bleaching). Ablation of tissue from mesoglea (18%) was also observed. Colonies with unexplained tissue loss showed atrophy and thinning of the epidermis (89%), characterized by cuboidal instead of pseudocolumnar cells normally found in healthy pseudocolumnar ciliated epithelium. Bacterial aggregates between the mesoglea and gastrodermis (11%) were very conspicuous in healthy and diseased corals. Lesions produced by fish bites and gastropods were associated with tissue atrophy (40%) and, in some cases, algal overgrowth near the lesion (20%). No infectious agents

  13. A hybrid zone between Bathymodiolus mussel lineages from eastern Pacific hydrothermal vents

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    Johnson Shannon B

    2013-01-01

    Full Text Available Abstract Background The inhabitants of deep-sea hydrothermal vents occupy ephemeral island-like habitats distributed sporadically along tectonic spreading-centers, back-arc basins, and volcanically active seamounts. The majority of vent taxa undergo a pelagic larval phase, and thus varying degrees of geographical subdivision, ranging from no impedance of dispersal to complete isolation, often exist among taxa that span common geomorphological boundaries. Two lineages of Bathymodiolus mussels segregate on either side of the Easter Microplate, a boundary that separates the East Pacific Rise from spreading centers connected to the Pacific-Antarctic Ridge. Results A recent sample from the northwest flank of the Easter Microplate contained an admixture of northern and southern mitochondrial haplotypes and corresponding alleles at five nuclear gene loci. Genotypic frequencies in this sample did not fit random mating expectation. Significant heterozygote deficiencies at nuclear loci and gametic disequilibria between loci suggested that this transitional region might be a ‘Tension Zone’ maintained by immigration of parental types and possibly hybrid unfitness. An analysis of recombination history in the nuclear genes suggests a prolonged history of parapatric contact between the two mussel lineages. We hereby elevate the southern lineage to species status as Bathymodiolus antarcticus n. sp. and restrict the use of Bathymodiolus thermophilus to the northern lineage. Conclusions Because B. thermophilus s.s. exhibits no evidence for subdivision or isolation-by-distance across its 4000 km range along the EPR axis and Galápagos Rift, partial isolation of B. antarcticus n. sp. requires explanation. The time needed to produce the observed degree of mitochondrial differentiation is consistent with the age of the Easter Microplate (2.5 to 5.3 million years. The complex geomorphology of the Easter Microplate region forces strong cross-axis currents that

  14. A new Lepeophtheirus (Copepoda: Siphonostomatoida: Caligidae from Isla del Coco National Park, Costa Rica, Eastern Tropical Pacific

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    Eduardo Suárez-Morales

    2012-11-01

    Full Text Available Among the several groups of copepods that are teleost parasites, the siphonostomatoid family Caligidae is by far the most widespread and diverse. With more than 108 nominal species, the caligid genus Lepeophtheirus von Nordmann is one of the most speciose. There are no reports of this genus in Costa Rican waters. A new species of Lepeophtheirus is herein described based on female specimens collected from plankton samples in waters off Bahía Wafer, isla del Coco, an oceanic island in the Eastern Tropical Pacific. The new species, L. alvaroi sp. nov., has some affinities with other congeners bearing a relatively short abdomen, a wider than long genital complex and a 3-segmented exopod of leg 4. it differs from most of these species by the presence of an unbranched maxillular process and by the relative lengths of the terminal claws of leg 4, with two equally long elements. it is most closely related to two other Eastern Pacific species: L. dissimulatus Wilson, 1905 and L. clarionensis Shiino, 1959. it differs from these species by the proportions and shape of the genital complex, the shape of the sternal furca, the relative length of the maxillar segments, the absence of a pectiniform process on the distal maxillar segment, the length of leg 4 and the armature of leg 5. The new species represents the first Lepeophtheirus described from Costa Rican waters of the Pacific. The low diversity of this genus in this tropi- cal region is explained by its tendency to prefer hosts from temperate latitudes. Until further evidence is found, the host of this Lepeophtheirus species remains unknown.Entre los varios grupos de copépodos que son parásitos de teleósteos, la familia sifonostomatoide Caligidae incluye los más dispersos y diversos. Con más de 108 especies nominales, el género de calígidos Lepeophtheirus von Nordmann es uno de los más diversos. No existen registros previos de este género en aguas de Costa Rica. Se describe una nueva especie de

  15. Protemblemaria perla, a new species of tube blenny (Perciformes: Chaenopsidae) from the tropical eastern Pacific.

    Science.gov (United States)

    Hastings, P A

    2001-07-01

    Protemblemaria perla, from Isla del Rey, Islas Perlas, Panama, is distinctive in having a long unbranched cirrus on the posterior nostril, a U-shaped fleshy ridge bearing fleshy flaps and a pair of papillae on the nape, a relatively high number (18) of segmented dorsal-fin rays, and small rust-colored spots on the dorsal fin. Protemblemaria perla and P. punctata, from the southern Caribbean, share several morphological features and form a transisthmian species pair. Although the degree of color variation is unknown in P. perla, color varies greatly in P. bicirris and P. punctata, both of which have an orange morph.

  16. Feeding ecology of elasmobranch fishes in coastal waters of the Colombian Eastern Tropical Pacific.

    Science.gov (United States)

    Navia, Andrés F; Mejía-Falla, Paola A; Giraldo, Alan

    2007-09-18

    Stomach contents of 131 specimens of five elasmobranch species (Mustelus lunulatus, Dasyatis longa, Rhinobatos leucorhynchus, Raja velezi and Zapteryx xyster) caught in the central fishing zone in the Pacific Ocean of Colombia were counted and weighed to describe feeding habits and dietary overlaps. Twenty-one prey items belonging to four major groups (stomatopods, decapods, mollusks and fish) were identified. Decapod crustaceans were the most abundant prey found in stomachs. The mantis shrimp Squilla panamensis was the main prey item in the diet of M. lunulatus; tiger shrimp Trachypenaeus sp. was the main prey item in the diet of Rhinobatos leucorhynchus and Raja velezi, and Penaeidae shrimp were the main prey items in the diet of Z. xyster. Furthermore, fish were important in the diet of Raja velezi, Z. xyster and D. longa. The greatest diet breadth corresponded to Z. xyster whereas M. lunulatus was the most specialized predator. Finally, four significant diet overlaps between the five species were found, attributable mainly to Squillidae, Penaeidae and Fish. Shrimps (Penaeidae and stomatopods) and benthic fishes were the most important food types in the diet of the elasmobranch species studied. Diet breadth and overlap were relatively low. Determination of food resource partitioning among the batoid species studied was not possible. However, we identified partitions in other niche axes (time of feeding activity and habitat utilization). It is possible to assume that diffuse competition could be exceeding the biunivocal competition among the studied species. Therefore, this assemblage would have a strong tendency to trophic guild formation.

  17. Nd isotope as the tracer of seawater evolution of early Miocene in the eastern Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Fifty-six samples of nannofossil ooze were collected from Core PC5794 in the northern equatorial Pacific at 5 cm intervals. With the methods of mass spectrometer (VG354) and ICP, the Nd isotopic compositions εNd(t ), Mn contents and Mg/Sr ratios of carbonate phase have been analyzed. CaCO3 contents of bulk sediments were obtained by dissolution of 0.5 mol/L HCl. Based on these data, the high-resolution εNd(t) profile of seawater in early Miocene with core depth(or time) have been established. The values of εNd(t) range from -6.2 to -2.97 and 4 fluctuation cycles existed during 24.06-22.02 Ma. 4 low εNd(t) values (about -6.4) correspond to high CaCO3 contents, which implicates that there were 4 cold epochs or 4 times of Antarctic Bottom Water activity. They occurred at the time of 24.06 Ma, 23.85 Ma, 22.88 Ma and 22.26 Ma, respectively. High εNd(t ) values correspond to the high Mn contents and high values of Mg/Sr ratio, which indicates the existence of 4 intense hydrothermal activity periods during 24.06-22 Ma, the durations of them are 4.05-23.98 Ma, 23.69-23.15 Ma, 22.74-22.37 Ma and 22.06-22.02 Ma, respectively.

  18. Nd isotope as the tracer of seawater evolution of early Miocene in the eastern Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    LIUJihua; CHENLirong; WANGYingxi; HANJianxiu

    2003-01-01

    Fifty-six samples of nannofossil ooze were collected from Core PC5794 in the northern equatorial Pacific at 5 cm intervals. With the methods of mass spectrometer (VG354) and ICP, the Nd isotopic compositions (εNd(t)), Mn contents and Mg/Sr ratios of carbonate phase have been analyzed. CaCO3 contents of bulk sediments were obtained by dissolution of 0.5 mol/L HCl. Based on these data, the high-resolution εNd(t) profile of seawater in early Miocene with core depth(or time) have been established. The values of εNd(t) range from -6.2 to -2.97 and 4 fluctuation cycles existed during 24.06-22.02 Ma. 4 low εNd(t) values (about -6.4) correspond to high CaCO3 contents, which implicates that there were 4 cold epochs or 4 times of Antarctic Bottom Water activity. They occurred at the time of 24.06 Ma, 23.85 Ma,22.88 Ma and 22.26 Ma, respectively. High εNd(t) values correspond to the high Mn contents and high values of Mg/Sr ratio, which indicates the existence of 4 intense hydrothermal activity periods during 24.06-22 Ma, the durations of them are 4.05-23.98 Ma, 23.69-23.15 Ma, 22.74-22.37 Ma and 22.06-22.02 Ma, respectively.

  19. Benthic Macrofauna Associated with Submerged Bottoms of a Tectonic Estuary in Tropical Eastern Pacific

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    Carlos E. Guevara-Fletcher

    2011-01-01

    Full Text Available The composition and distribution of the main associations of submerged macrobenthos of Bahía Málaga (Colombian pacific coast, were studied in relation to the distribution of hard and soft substrates and some abiotic factors. Eight localities were sampled during six months: three in the external border of the estuary and five in the inner part. In total, 728 organisms were registered, belonging to 207 species, 132 genera, 86 families, and 14 orders of six invertebrate groups (Porifera, Cnidaria, Polychaeta, Mollusca, Crustacea, and Echinodermata. The submerged bottoms presented soft and hard substrates, with rocks and thick sand in five sites, soft bottoms with fine sand in one, and soft bottoms with slime and clay in two. The temperature and salinity values were higher in the external localities, while dissolved oxygen and pH were higher in the internal localities. The localities with hard substrates presented the highest richness of species while the soft substrates, were characterized by a paucity of species and individuals. The similarity classification analyses showed two groups: one characterized by having 61 species in common and high richness with 113 exclusive species. The other group with low diversity and richness values, 37 species in common and 23 exclusive species.

  20. Transport of North Pacific 137Cs labeled waters to the south-eastern Atlantic Ocean

    Science.gov (United States)

    Sanchez-Cabeza, J. A.; Levy, I.; Gastaud, J.; Eriksson, M.; Osvath, I.; Aoyama, M.; Povinec, P. P.; Komura, K.

    2011-04-01

    During the reoccupation of the WOCE transect A10 at 30°S by the BEAGLE2003 cruise, the SHOTS project partners collected a large number of samples for the analysis of isotopic tracers. 137Cs was mostly deposited on the oceans surface during the late 1950s and early 1960s, after the atmospheric detonation of large nuclear devices, which mostly occurred in the Northern Hemisphere. The development of advanced radioanalytical and counting techniques allowed to obtain, for the first time in this region, a zonal section of 137Cs water concentrations, where little information existed before, thus constituting an important benchmark for further studies. 137Cs concentrations in the upper waters (0-1000 m) of the south-eastern Atlantic Ocean are similar to those observed in the south-western Indian Ocean, suggesting transport of 137Cs labeled waters by the Agulhas current to the Benguela Current region. In contrast, bomb radiocarbon data do not show this feature, indicating the usefulness of 137Cs as a radiotracer of water mass transport from the Indian to the South Atlantic Ocean.

  1. Feeding ecology of elasmobranch fishes in coastal waters of the Colombian Eastern Tropical Pacific

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    Mejía-Falla Paola A

    2007-09-01

    Full Text Available Abstract Background Stomach contents of 131 specimens of five elasmobranch species (Mustelus lunulatus, Dasyatis longa, Rhinobatos leucorhynchus, Raja velezi and Zapteryx xyster caught in the central fishing zone in the Pacific Ocean of Colombia were counted and weighed to describe feeding habits and dietary overlaps. Results Twenty-one prey items belonging to four major groups (stomatopods, decapods, mollusks and fish were identified. Decapod crustaceans were the most abundant prey found in stomachs. The mantis shrimp Squilla panamensis was the main prey item in the diet of M. lunulatus; tiger shrimp Trachypenaeus sp. was the main prey item in the diet of Rhinobatos leucorhynchus and Raja velezi, and Penaeidae shrimp were the main prey items in the diet of Z. xyster. Furthermore, fish were important in the diet of Raja velezi, Z. xyster and D. longa. The greatest diet breadth corresponded to Z. xyster whereas M. lunulatus was the most specialized predator. Finally, four significant diet overlaps between the five species were found, attributable mainly to Squillidae, Penaeidae and Fish. Conclusion Shrimps (Penaeidae and stomatopods and benthic fishes were the most important food types in the diet of the elasmobranch species studied. Diet breadth and overlap were relatively low. Determination of food resource partitioning among the batoid species studied was not possible. However, we identified partitions in other niche axes (time of feeding activity and habitat utilization. It is possible to assume that diffuse competition could be exceeding the biunivocal competition among the studied species. Therefore, this assemblage would have a strong tendency to trophic guild formation.

  2. Uranium and plutonium in anoxic marine sediments of the Santiago River mouth (Eastern Pacific, Mexico).

    Science.gov (United States)

    Almazán-Torres, María Guadalupe; Ordóñez-Regil, Eduardo; Ruiz-Fernández, Ana Carolina

    2016-11-01

    The uranium (U) and plutonium (Pu) content with depth in a sediment core collected in the continental shelf off the mouth of the Santiago River in the Mexican Pacific was studied to evaluate the contamination effects of the effluent of the Santiago-Lerma River as it moves into the sea. The large mass of terrestrial detritus delivered by the river influences the physicochemical and geochemical processes in the seafloor. Abnormal concentrations of U and Pu in sediments were examined as indicative of the effects of anoxic conditions. One of the indicators of pollution of seawater is the bacterial activity of the shallow seabed layer; and among the prevailing bacteria, the magnetotactic ones induce the formation of euhedral and framboidal shapes (pyrite). These pyrite entities are by-products of anoxic environments loaded with decomposing detrital material and are very abundant in the surface layers of the sediment core analyzed. The pyrite formation is the result of a biochemical reaction between iron and organic sulphur reduced by bacteria, and the pyrite entities precipitate to the seafloor. In the same upper zone of the profile, (238)U is readily immobilized, while (234)U is oxidized and dissolved in seawater by the effect of hot atom chemistry. This may cause the activity ratio (AR) (234)U/(238)U disequilibrium (near 0.41). Furthermore, in the shallow layer of the sediment core, an abnormally high concentration of (239+240)Pu was detected. In this upper layer, the activity concentrations found were 3.19 Bq kg(-1) for (238)U, 1.32 kg(-1) for (234)U and 2.78 Bq kg(-1) for (239+240)Pu. In the lower fractions of the sediment core, normal values of AR (234)U/(238)U (≈1) were found, with traces of (239+240)Pu.

  3. Nitrous oxide distribution and its origin in the central and eastern South Pacific Subtropical Gyre

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    J. Charpentier

    2007-05-01

    Full Text Available The biogeochemical mechanism of bacterial N2O production in the ocean has been the subject of many discussions in recent years. New isotopomeric tools can help further knowledge on N2O sources in natural environments. This research shows and compares hydrographic, nitrous oxide concentration, and N2O isotopic and isotopomeric data from three stations across the South Pacific Ocean, from the center of the subtropical oligotrophic gyre (~26° S; 114° W to the upwelling zone along the central Chilean coast (~34° S. Althought AOU/N2O and NO3 trends support the idea that most of N2O source (mainly from intermediate water (200–1000 m come from nitrification, N2O isotopomeric composition (intramolecular distribution of 15N isotopes in N2O reveals an abrupt change in the mechanism of nitrous oxide production, always observed through lower SP (site preference of 15N, at a high – stability layer, where particles could act as microsites and N2O would be produced by nitrifier denitrification (reduction of nitrite to nitrous oxide mediated by primary nitrifiers. There, nitrifier denitrification can account for 40% and 50% (center and east border of the gyre, respectively of the nitrous oxide produced in this specific layer. This process could be associated with the deceleration of sinking organic particles in highly stable layers of the water column. In constrast, coastal upwelling system is characterized by oxygen deficient condition and some N deficit in a eutrophic system. Here, nitrous oxide accumulates up to 480% saturation, and isotopic and isotopomer signal show highly complex nitrous oxide production processes, which presumably reflect both the effect of nitrification and denitrification at low oxygen levels on N2O production, but non N2O consumption by denitrification was observed.

  4. Nitrous oxide distribution and its origin in the central and eastern South Pacific Subtropical Gyre

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    J. Charpentier

    2007-09-01

    Full Text Available The mechanisms of microbial nitrous oxide (N2O production in the ocean have been the subject of many discussions in recent years. New isotopomeric tools can further refine our knowledge of N2O sources in natural environments. This study compares hydrographic, N2O concentration, and N2O isotopic and isotopomeric data from three stations along a coast-perpendicular transect in the South Pacific Ocean, extending from the center (Sts. GYR and EGY of the subtropical oligotrophic gyre (~26° S; 114° W to the upwelling zone (St. UPX off the central Chilean coast (~34° S. Although AOU/N2O and NO3 trends support the idea that most of the N2O (mainly from intermediate water (200–600 m comes from nitrification, N2O isotopomeric composition (intramolecular distribution of 15N isotopes expressed as SP (site preference of 15N shows low values (10 to 12permil that could be attributed to the production through of microbial nitrifier denitrification (reduction of nitrite to N2O mediated by ammonium oxidizers. The coincidence of this SP signal with high – stability layer, where sinking organic particles can accumulate, suggests that N2O could be produced by nitrifier denitrification inside particles. It is postulated that deceleration of particles in the pycnocline can modify the advection - diffusion balance inside particles, allowing the accumulation of nitrite and O2 depletion suitable for nitrifier denitrication. As lateral advection seems to be relatively insignificant in the gyre, in situ nitrifier denitrification could account for 40–50% of the N2O produced in this layer. In contrast, coastal upwelling system is characterized by O2 deficient condition and some N deficit in a eutrophic system. Here, N2O accumulates up to 480% saturation, and isotopic and

  5. The Sorcerer II Global Ocean Sampling expedition: northwest Atlantic through eastern tropical Pacific.

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    Douglas B Rusch

    2007-03-01

    Full Text Available The world's oceans contain a complex mixture of micro-organisms that are for the most part, uncharacterized both genetically and biochemically. We report here a metagenomic study of the marine planktonic microbiota in which surface (mostly marine water samples were analyzed as part of the Sorcerer II Global Ocean Sampling expedition. These samples, collected across a several-thousand km transect from the North Atlantic through the Panama Canal and ending in the South Pacific yielded an extensive dataset consisting of 7.7 million sequencing reads (6.3 billion bp. Though a few major microbial clades dominate the planktonic marine niche, the dataset contains great diversity with 85% of the assembled sequence and 57% of the unassembled data being unique at a 98% sequence identity cutoff. Using the metadata associated with each sample and sequencing library, we developed new comparative genomic and assembly methods. One comparative genomic method, termed "fragment recruitment," addressed questions of genome structure, evolution, and taxonomic or phylogenetic diversity, as well as the biochemical diversity of genes and gene families. A second method, termed "extreme assembly," made possible the assembly and reconstruction of large segments of abundant but clearly nonclonal organisms. Within all abundant populations analyzed, we found extensive intra-ribotype diversity in several forms: (1 extensive sequence variation within orthologous regions throughout a given genome; despite coverage of individual ribotypes approaching 500-fold, most individual sequencing reads are unique; (2 numerous changes in gene content some with direct adaptive implications; and (3 hypervariable genomic islands that are too variable to assemble. The intra-ribotype diversity is organized into genetically isolated populations that have overlapping but independent distributions, implying distinct environmental preference. We present novel methods for measuring the genomic

  6. Mid-term coral-algal dynamics and conservation status of a Gorgona Island (Tropical Eastern Pacific coral reef

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    Fernando A Zapata

    2010-05-01

    Full Text Available Colombian coral reefs, as other reefs worldwide, have deteriorated significantly during the last few decades due to both natural and anthropogenic disturbances. The National Monitoring System for Coral Reefs in Colombia (SIMAC was established in 1998 to provide long-term data bases to assess the changes of Colombian coral reefs against perturbations and to identify the factors responsible for their decline or recovery. On the Pacific coast, data on coral and algal cover have been collected yearly during seven consecutive years (1998-2004 from 20 permanent transects in two sites at La Azufrada reef, Gorgona Island. Overall, coral cover was high (55.1%-65.7% and algal cover low (28.8%-37.5% and both exhibited significant changes among years, most notably on shallow areas. Differences between sites in both coral and algal cover were present since the study began and may be explained by differences in sedimentation stress derived from soil runoff. Differences between depths most likely stem from the effects of low tidal sub-aerial exposures. Particularly intense sub-aerial exposures occurred repeatedly during January-March, 2001 and accounted for a decrease in coral and an increase in algal cover on shallow depths observed later that year. Additionally, the shallow area on the Northern site seems to be negatively affected by the combined effect of sedimentation and low tidal exposure. However, a decrease in coral cover and an increase of algal cover since 2001 on deep areas at both sites remain unexplained. Comparisons with previous studies suggest that the reef at La Azufrada has been more resilient than other reefs in the Tropical Eastern Pacific (TEP, recovering pre-disturbance (1979 levels of coral cover within a 10 year period after the 1982-83 El Niño, which caused 85% mortality. Furthermore, the effects of the 1997-98 El Niño, indicated by the difference in overall live coral cover between 1998 and 1999, were minor (<6% reduction. Despite

  7. Mid-term coral-algal dynamics and conservation status of a Gorgona Island (Tropical Eastern Pacific) coral reef.

    Science.gov (United States)

    Zapata, Fernando A; Rodríguez-Ramírez, Alberto; Caro-Zambrano, Carlos; Garzón-Ferreira, Jaime

    2010-05-01

    Colombian coral reefs, as other reefs worldwide, have deteriorated significantly during the last few decades due to both natural and anthropogenic disturbances. The National Monitoring System for Coral Reefs in Colombia (SIMAC) was established in 1998 to provide long-term data bases to assess the changes of Colombian coral reefs against perturbations and to identify the factors responsible for their decline or recovery. On the Pacific coast, data on coral and algal cover have been collected yearly during seven consecutive years (1998-2004) from 20 permanent transects in two sites at La Azufrada reef, Gorgona Island. Overall, coral cover was high (55.1%-65.7%) and algal cover low (28.8%-37.5%) and both exhibited significant changes among years, most notably on shallow areas. Differences between sites in both coral and algal cover were present since the study began and may be explained by differences in sedimentation stress derived from soil runoff. Differences between depths most likely stem from the effects of low tidal sub-aerial exposures. Particularly intense sub-aerial exposures occurred repeatedly during January-March, 2001 and accounted for a decrease in coral and an increase in algal cover on shallow depths observed later that year. Additionally, the shallow area on the Northern site seems to be negatively affected by the combined effect of sedimentation and low tidal exposure. However, a decrease in coral cover and an increase of algal cover since 2001 on deep areas at both sites remain unexplained. Comparisons with previous studies suggest that the reef at La Azufrada has been more resilient than other reefs in the Tropical Eastern Pacific (TEP), recovering pre-disturbance (1979) levels of coral cover within a 10 year period after the 1982-83 El Niño, which caused 85% mortality. Furthermore, the effects of the 1997-98 El Niño, indicated by the difference in overall live coral cover between 1998 and 1999, were minor (coral cover in 2004 was as high as

  8. Observations of heterogeneous reactions between Asian pollution and mineral dust over the Eastern North Pacific during INTEX-B

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    C. S. McNaughton

    2009-03-01

    Full Text Available In-situ airborne measurements of trace gases, aerosol size distributions, chemistry and optical properties were conducted over Mexico and the Eastern North Pacific during MILAGRO and INTEX-B. Heterogeneous reactions between secondary aerosol precursor gases and mineral dust during long-range transport lead to irreversible sequestration of sulfur and nitrogen compounds in the supermicrometer particulate size range.

    Simultaneous measurements of aerosol size distributions and weak-acid soluble calcium result in an estimate of 11 wt% of CaCO3 for Asian dust. During transport across the North Pacific, 10–30% of the CaCO3 is converted to CaSO4 or Ca(NO32 through reactions with trace gases. The 11-year record from the Mauna Loa Observatory confirm these findings, indicating that, on average, 16% of the CaCO3 has reacted to form CaSO4 and 14% has reacted to form Ca(NO32. Heterogeneous reactions resulting in ~3% increase in dust solubility is shown to have an insignificant effect on their optical properties compared to their variability in-situ. However, competition between supermicrometer dust and submicrometer primary aerosol for condensing secondary aerosol species led to a 25% smaller number median diameter for the accumulation mode aerosol. A 10–25% reduction of accumulation mode number median diameter results in a 30–70% reduction in submicrometer light scattering at relative humidities in the 80–95% range. At 80% RH submicrometer light scattering is only reduced ~3% due to a higher mass fraction of hydrophobic refractory components in the dust-affected accumulation mode aerosol. Thus reducing the geometric mean diameter of the submicrometer aerosol has a much larger effect on aerosol optics than changes to the hygroscopic:hydrophobic mass fractions of the aerosol.

    In the presence of dust, nitric acid concentrations are

  9. Variations in terrigenous matter transport evaluated by plant terpenoid analysis in the Neogene eastern equatorial Pacific sediment

    Science.gov (United States)

    Nakamura, H.; Sawada, K.; Yamamoto, S.; Kobayashi, M.

    2012-12-01

    We analyze land plant biomarkers in sediments recovered during the IODP Expeditions 320/321, the Pacific Equatorial Age Transect (PEAT), to reconstruct variations in terrestrial input in the eastern equatorial Pacific Ocean, as well as to evaluate transport systems of terrigenous matter from land to ocean. We used the Neogene sediments (23-0.23 Ma) recovered from site U1337. We could identify cadalene (sesquiterpenoid), as well as series of aromatic abietane type diterpenoids (e.g. retene) from most samples. These terpenoids are derived from biomolecules that constitute plant resin and supportive tissues. Plant-derived compounds in deep-sea sediments are considered that initially transported via fluvial process, followed by redistribution by gravity flow to the deeper part. Although, the typical pelagic setting of site U1337, even far from land across the mid-ocean-ridge, exclude such pathway. Therefore, the variations in mass accumulation rate (MAR) of plant terpenoids in this site depend eolian transportation and can be used as an indicator of change in atmospheric circulation. The increasing spikes in MAR of plant terpenoids were observed in the horizons of 16 Ma, 14 Ma, 12 Ma, 10 Ma, 9 - 8 Ma, 7 Ma and 2.5 - 1Ma. It is found that some of the spikes, 14 Ma, 7 Ma, 2.5 - 1 Ma correspond to the East Antarctica Ice Sheet event (EAIS), the Biogenic bloom event, and the Northern Hemisphere Glaciation (NHG), respectively. Furthermore, the degree of aromatization in diterpenoids, which represented by retene to the sum of abietane type diterpenoids, tends to increase concurrently with the MAR of total plant terpenoids. The aromatization of plant terpenoids take place under thermal maturation after deposition as well as in earlier processes such as biomass burning. In the U1337 sediments, the degree of aromatization of diterpenoids was uncorrelated with the age or depositional depth, suggesting its variations retain potential for paleoclimatic application. For example

  10. Planktonic foraminifera as recorders of sea surface hydrography in the Eastern Tropical North Pacific (Gulf of Tehuantepec, MX)

    Science.gov (United States)

    Gibson, K.; Thunell, R.; Machain-Castillo, M. L.; Wejnert, K.; Nava-Fernández, X. A.; Rodriguez-Ramírez, A.; Tappa, E.

    2014-12-01

    The Gulf of Tehuanetpec (GoT) (14°-16°N and 92°-96°W) is located in the Eastern Tropical North Pacific, a region that is sensitive to changes in both Atlantic-Pacific water vapor transport as well as changes in ENSO. Within the ETNP, the GoT is unique in that it experiences significant changes in temperature (ΔT = 8-10°C) and salinity (ΔS = 3) associated with seasonal variations in precipitation and wind-driven upwelling. Establishing robust relationships between δ18O and Mg/Ca of foraminiferal calcite to sea surface temperature (SST) and sea surface salinity (SSS) in this region can then be used to study past changes in Atl-Pac water vapor transport and ENSO and how these relate to regional and global climate change. We present here a six year (2006-2012), weekly to biweekly resolved record of paired δ18O-Mg/Ca analyses of the planktonic foraminfer Globigerina bulloides, collected from a sediment trap mooring in the GoT (15° 38.826N, 95° 16.905 W). The G. bulloides δ18O values ranges from -0.14‰ to - 3.98‰, equivalent to ~16°C temperature, or nearly twice the observed instrumental change in SST. To help constrain the temperature influence on the δ18Ocalcite signal, Mg/Ca values were converted to temperature using previously published equations for G. bulloides. In addition, we calculated new equations using the Mg/Ca and satellite SST data. Depending on the calibration equation used, G. bulloides from the GoT show a ~5-8% change in Mg/Ca with temperature, and show generally good agreement with SST, particularly in winter upwelling months. The agreement between SST and Mg/Ca-based temperatures is less robust during the winter months of 2009, when a moderate El Niño year resulted in warmer and fresher surface conditions in the GoT than pervious and following years, indicating a deeper habitat depth for G. bulloides and perhaps reduced upwelling during El Niño conditions.

  11. Mitochondrial genome of the bullet tuna Auxis rochei from Indo-West Pacific collection provides novel genetic information about two subspecies.

    Science.gov (United States)

    Li, Mingming; Guo, Liang; Zhang, Heng; Yang, Sen; Chen, Xinghan; Lin, Haoran; Meng, Zining

    2016-09-01

    Previously morphological studies supported the division of the bullet tuna into the two subspecies, Auxis rochei rochei and A. rochei eudorax. As a cosmopolitan species, A. rochei rochei ranges in the Indo-West Pacific and Atlantic oceans, while A. rochei eudorax inhabits in eastern Pacific region. Here, we used the HiSeq next-generation sequencing technique to determine the mitochondrial genome (mitogenome) of A. rochei from Indo-West Pacific collection, and then compared our data with mitogenomic sequences of the Atlantic and eastern Pacific retrieved from NCBI database. Results showed the mitogenome of A. rochei from three geographic collections shared the same genes and gene order, similar to typical teleosts. Also, we examined a low level of nucleotide diversity among these mitogenomic sequences. Interestingly, nucleotide diversity of intra-subspecies (Atlantic versus Indo-West) was higher than that of inter-subspecies (Atlantic versus eastern Pacific, Indo-West versus eastern Pacific).

  12. Understanding Differences in the Nitrogen Cycle in Low-Oxygen Zones in the Eastern Tropical North Pacific

    Science.gov (United States)

    Wood, C.; Travis, N. M.; Forbes, M. S.; Casciotti, K. L.

    2016-12-01

    Hypoxic and anoxic zones are found in oceans worldwide. These zones can be caused by warm water "caps" that trap colder water underneath the warm water so the cold water cannot replenish its oxygen. Processes such as global warming and eutrophication can also contribute to such oxygen-depleted zones. Thus, it is important to study these zones to investigate and reveal the impact humans have on ecosystems worldwide so we can fix the problems we have caused. The Eastern Tropical North Pacific (ETNP), off the southwestern coast of Mexico, contains a natural-oxygen deficient zone. On a research cruise to the ETNP in April 2016, incubations were conducted to measure the rates of nitrification in the upper water column (upper 100 m) at three stations. Incubations were conducted in light and dark bottles spiked with 15N-containing nitrite. In this study, nitrite concentration in incubation starting points was analyzed. For each point, four depths of increasing depth (they varied depending on the station) were analyzed, and for each depth there were three samples. For each sample five absorbance measurements were averaged to calculate nitrite concentration against known standards. Concentrations of nitrite were found to increase moving into the oxygen deficient zone. The nitrite peaks at the coastal stations were at shallower depths than the peak at the centermost station in the low-oxygen zone. At the centermost station within the oxygen-deficient region, the nitrite concentration at the primary peak was 1.6µM, which was the highest point out of all the stations. This nitrite concentration data will be expanded to all stations where 15N addition incubation experiments were performed. In the future, these time-zero data will be combined with time-24 data to calculate nitrite oxidation rates based on 15N isotope analysis. Measuring nitrite oxidation rates will help us further understand processes structuring nitrite accumulation in the ETNP low-oxygen zone.

  13. Modeling a habitat suitability index for the eastern fall cohort of Ommastrephes bartramii in the central North Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    CHEN Xinjun; TIAN Siquan; LIU Bilin; CHEN Yong

    2011-01-01

    The eastern fall cohort of the neon flying squid, Ommastrephes bartramii, has been commercially exploited by the Chinese squid jigging fleet in the central North Pacific Ocean since the late 1990s. To understand and identify their optimal habitat, we have developed a habitat suitability index (HSI) model using two potential important environmental variables - sea surface temperature (SST) and sea surface height anomaly (SSHA) - and fishery data from the main fishing ground (165°-180°E) during June and July of 1999-2003. A geometric mean model (GMM), minimum model (MM) and arithmetic weighted model (AWM) with different weights were compared and the best HSI model was selected using Akaike's information criterion (AIC). The performance of the developed HSI model was evaluated using fishery data for 2004. This study suggests that the highest catch per unit effort (CPUE) and fishing effort are closely related to SST and SSHA. The best SST- and SSHA-based suitability index (SI) regression models were SISST-bsed = 0.7SIeffort-SST + 0.3 SICPUE-SST, and SISSHA-based = 0.5SIeffon-SSHA + 0.5SICP,UE-SSHA,respectively, showing that fishing effort is more important than CPUE in the estimation of SI. The bestHSI model was the AWM, defined as HSI=0.3SISST-based+ 0.7SISSHA-based, indicating that SSHA is moreimportant than SST in estimating the HSI of squid. In 2004, monthly HSI values greater than 0.6 coincidedwith the distribution of productive fishing ground and high CPUE in June and July, suggesting that themodels perform well. The proposed model provides an important tool in our efforts to develop forecastingcapacity of squid spatial dynamics.

  14. Ultrafine sea spray aerosol over the south eastern Pacific: open-ocean contributions to marine boundary layer CCN

    Directory of Open Access Journals (Sweden)

    R. Blot

    2013-02-01

    Full Text Available Accurate measurements of natural aerosol emissions over the ocean are needed to estimate the anthropogenic impact on the environment. In this study, we measured Sea Spray Aerosol (SSA concentrations with diameters larger than 0.040 μm produced by open-ocean breaking waves over the SEP (South Eastern Pacific. Robust statistics were established through repeated airborne flights over 1000 km along 20° S from the coastline of Chile to 85° W during VOCALS-Rex (VAMOS Ocean-Cloud-Atmosphere-Land-Study Regional Experiment. Non-volatile SSA number concentrations were inferred using a thermally resolved technique constrained for clean conditions with Ångström exponent below 0.5, Black Carbon (BC mass concentration at values lower than 15 ng m−3 and Organic aerosols (Org concentration less than 0.02 μg m−3. We found that number concentrations of SSA active as CCN for a supersaturation of 0.25% varied between 17 cm−3 and 36 cm−3 but these did not increase with the increasing mean wind speed typically observed further offshore along 20° S. Concurrent increases in mean offshore precipitation rate in excess of about 1 mm d−1 indicate scavenging of SSA by precipitation exceeds increases in production at wind speeds above about 8 m s−1. This demonstrates the critical role of precipitation as a major sink of SSA over the remote ocean. Finally, we found that under clean conditions and for estimated stratus supersaturations between 0.20% and 0.43%, SSA represented about 20% of the total ambient CCN along 20° S.

  15. Large multicellular filamentous bacteria under the oxygen minimum zone of the eastern South Pacific: a forgotten biosphere

    Science.gov (United States)

    Gallardo, Victor Ariel; Espinoza, Carola

    2007-09-01

    In the soft reduced sediments of the continental shelf, below the oxygen minimum zone (OMZ) of the eastern South Pacific (ESP), peculiar microbial communities have been disclosed which include a variety of large prokaryotes, protists and small metazoans. Dominant among the prokaryotes are large multi-cellular filamentous bacteria which, according to their size range, are roughly divided into megabacteria and macrobacteria. The former group is made up of a few species of Gamma Proteobacteria of the genera Thioploca and Beggiatoa and the second group includes a diversity of phenotypes. Protists include ciliates, flagellates, and foraminifers and the metazoans are mostly nematodes and small polychaetes. A significant similarity has been found in the exploitation of the area/volume relationship among these large bacteria and their fossil analog forms as described from pre-Cambrian rocks. For the same reason, the latter have mostly been referred to as algae or cyanobacteria in the literature. The presence of these seemingly ancient bacteria in the sediments of the oxygen minimum zones of the ESP, one of the most productive but also ecologically most inefficient marine ecosystems of the world, suggests that such setting must have prevailed throughout the geological history of the planet allowing for their survival and further that it might be considered an analog of Proterozoic ocean conditions. These non-cyanobacterial communities offer an alternative hypothesis to students of the evolution of life on Earth and may be of special interest to astrobiologists looking for life or traces of life in terrestrial or extraterrestrial environments since these do not necessarily imply a photosynthesis-based metabolism.

  16. Thermal adaptation of cytoplasmic malate dehydrogenases of eastern Pacific barracuda (Sphyraena spp): the role of differential isoenzyme expression

    Science.gov (United States)

    Lin; Somero

    1995-01-01

    Kinetic properties, electrophoretic patterns and thermal stabilities of cytoplasmic malate dehydrogenases (cMDHs) were compared in Eastern Pacific barracuda (Sphyraena spp) from different latitudes. All tissues of the tropical species S. ensis contained only a single, thermostable form of cMDH. Subtropical (S. lucasana) as well as north (S. argentea) and south (S. idiastes) temperate barracuda contained both thermostable and thermolabile cMDHs, the pattern characteristic of most teleosts. Kinetic studies using unfractioned cMDHs showed that the apparent Michaelis­Menten constant (Km) of cofactor (NADH) increased with temperature, but at the physiological temperatures of the four species, Km of NADH was conserved within a narrow range (20­23 µmol l-1). Thermostable and thermolabile cMDHs were chromatographically separated and compared. Thermolabile cMDHs had higher Km values for NADH at all measurement temperatures than did thermostable cMDHs. Thermolabile cMDHs isolated from congeneric barracuda exhibited similar kinetic properties (Km versus temperature, optimal pH, optimal substrate and cofactor concentrations). Thermostable cMDHs, likewise, were similar among the barracuda. Conservation of Km in the differently thermally adapted barracudas is, therefore, apparently due to adjustments in the ratio of expression of the thermostable and thermolabile isoforms, rather than to temperature-adaptive differences among orthologous homologues, as is commonly found for enzymes encoded by a single gene locus. The effects of temperature on the Km of NADH for isolated thermostable and thermolabile cMDHs of a eurythermal goby, Gillichthys mirabilis, however, were consistent with adaptive change in orthologous homologues of cMDH. The selective basis for the absence of thermolabile cMDH in warm-adapted ectotherms, mammals and birds is discussed.

  17. Redescription of the poorly known planktonic copepod Pontellopsis lubbockii (Giesbrecht, 1889 (Pontellidae from the Eastern Tropical Pacific with a key to species

    Directory of Open Access Journals (Sweden)

    Eduardo Suarez-Morales

    2012-10-01

    Full Text Available During a survey of the epipelagic zooplankton carried out off the coast of the Mexican states of Jalisco and Colima, in the Eastern Tropical Pacific, female and male specimens of the poorly known calanoid copepod Pontellopsis lubbockii (Giesbrecht, 1889 were collected. Because previous descriptions and illustrations are largely incomplete and have caused some taxonomical confusion, this species is fully redescribed from specimens from the Mexican Pacific. The species has some characters that have been overlooked, but those related to the female genital double-somite are the most striking, it has two conical dorsal protuberances and a long ventral spiniform process unique of this species. The mouthparts of this species have not been hitherto described and figured, the flexible terminal setae of legs 3 and 4 is noteworthy. The male general morphology agrees in general with previous data, but new details of the leg 5 and geniculate antennule are added. Its mouthparts, with strong, serrate setae on the maxillae and maxillules, and a strong mandibular edge, suggest that this is a predator form. A dichotomous key for the identification of males and females of the species of Pontellopsis known from the Eastern Tropical Pacific is included.

  18. Redescription of the poorly known planktonic copepod Pontellopsis lubbockii (Giesbrecht, 1889) (Pontellidae) from the Eastern Tropical Pacific with a key to species.

    Science.gov (United States)

    Suárez-Morales, Eduardo; Kozak, Eva

    2012-01-01

    During a survey of the epipelagic zooplankton carried out off the coast of the Mexican states of Jalisco and Colima, in the Eastern Tropical Pacific, female and male specimens of the poorly known calanoid copepod Pontellopsis lubbockii (Giesbrecht, 1889) were collected. Because previous descriptions and illustrations are largely incomplete and have caused some taxonomical confusion, this species is fully redescribed from specimens from the Mexican Pacific. The species has some characters that have been overlooked, but those related to the female genital double-somite are the most striking, it has two conical dorsal protuberances and a long ventral spiniform process unique of this species. The mouthparts of this species have not been hitherto described and figured, the flexible terminal setae of legs 3 and 4 is noteworthy. The male general morphology agrees in general with previous data, but new details of the leg 5 and geniculate antennule are added. Its mouthparts, with strong, serrate setae on the maxillae and maxillules, and a strong mandibular edge, suggest that this is a predator form. A dichotomous key for the identification of males and females of the species of Pontellopsis known from the Eastern Tropical Pacific is included.

  19. Redescription of the poorly known planktonic copepod Pontellopsis lubbockii (Giesbrecht, 1889) (Pontellidae) from the Eastern Tropical Pacific with a key to species

    Science.gov (United States)

    Suárez-Morales, Eduardo; Kozak, Eva

    2012-01-01

    Abstract During a survey of the epipelagic zooplankton carried out off the coast of the Mexican states of Jalisco and Colima, in the Eastern Tropical Pacific, female and male specimens of the poorly known calanoid copepod Pontellopsis lubbockii (Giesbrecht, 1889) were collected. Because previous descriptions and illustrations are largely incomplete and have caused some taxonomical confusion, this species is fully redescribed from specimens from the Mexican Pacific. The species has some characters that have been overlooked, but those related to the female genital double-somite are the most striking, it has two conical dorsal protuberances and a long ventral spiniform process unique of this species. The mouthparts of this species have not been hitherto described and figured, the flexible terminal setae of legs 3 and 4 is noteworthy. The male general morphology agrees in general with previous data, but new details of the leg 5 and geniculate antennule are added. Its mouthparts, with strong, serrate setae on the maxillae and maxillules, and a strong mandibular edge, suggest that this is a predator form. A dichotomous key for the identification of males and females of the species of Pontellopsis known from the Eastern Tropical Pacific is included. PMID:23372406

  20. Three-dimensional distribution of larval fish habitats in the shallow oxygen minimum zone in the eastern tropical Pacific Ocean off Mexico

    Science.gov (United States)

    Davies, S. M.; Sánchez-Velasco, L.; Beier, E.; Godínez, Victor M.; Barton, Eric D.; Tamayo, A.

    2015-07-01

    Three-dimensional distribution of larval fish habitats was analyzed, from the upper limit of the shallow oxygen minimum zone (~0.2 mL/L) to the sea surface, in the eastern tropical Pacific Ocean off Mexico in February 2010. The upper limit rises from ~250 m depth in the entrance of the Gulf of California to ~80 m depth off Cabo Corrientes. Three larval fish habitats were defined statistically: (i) a Gulf of California habitat dominated by Anchoa spp. larvae (epipelagic species), constrained to the oxygenated surface layer (>3.5 mL/L) in and above the thermocline (~60 m depth), and separated by a salinity front from the Tropical Pacific habitat; (ii) a Tropical Pacific habitat, dominated by Vinciguerria lucetia larvae (mesopelagic species), located throughout the sampled water column, but with the highest abundance in the oxygenated upper layer above the thermocline; (iii) an Oxygen Minimum habitat defined mostly below the thermocline in hypoxic (tropical Pacific off Mexico, the shallow hypoxic water does not have dramatic effects on the total larval fish abundance but appears to affect species composition.

  1. Physical forcing and the dynamics of the pelagic ecosystem in the eastern tropical Pacific: simulations with ENSO-scale and global-warming climate drivers

    Energy Technology Data Exchange (ETDEWEB)

    Watters, G. M.; Olson, R. J. [Inter-American Tropical Tuna Commission, La Jolla, CA (United States); Francis, C.; Aydin, K. Y. [Washington Univ., School of Aquatic and Fisheries Sciences, Seattle, WA (United States); Fiedler, P. C.; Reilley, S. B. [NOAA Fisheries, LaJolla, CA (United States); Polovnia, J. J.; Boggs, C. H.; Essington, T. E. [NOAA Fisheries, Honolulu, HI (United States); Walters, C. J. [British Columbia Univ., Fisheries Centre, Vancouver, BC (Canada); Kitchell, J. F. [Wisconsin Univ., Center for Limnology, Madison, WI (United States)

    2003-09-01

    The effects of climate variation on animals at the middle and upper trophic levels in the eastern tropical Pacific Ocean was investigated at El Nino-Southern Oscillation (ENSO) scales. Objectives of the work were: (1) to explore how a single, ENSO-scale climate pulse might affect middle and upper trophic levels of the pelagic ecosystem in the eastern tropical Pacific Ocean; (2) explore ecosystem response to changes in periodicity of warm and cold events during sustained ENSO-scale cycling; and (3) explore how the greenhouse effect might affect pelagic ecosystem in the eastern tropical Pacific Ocean. Two physical forcing scenarios were used: (1) physical effects on phytoplankton biomass, and (2) simultaneous physical effects on phytoplankton biomass and predator recruitment. The effects of climate anomaly pulses, climatic cycles and global warming were simulated. Pulses caused oscillations to propagate through the ecosystem; cycles affected the shapes of these oscillations; and warming caused trends to develop. These results gave rise to several conclusions: (1) it seems unlikely that biomass trajectories of single populations at middle and upper trophic levels could be used to detect bottom-up effects; (2) under constant fishing mortality, direct physical effects on predator recruitment are the dominant source of interannual variability in pelagic ecosystems; (3) top-down effects of fishing are less able to cascade through the food web if direct effects are the dominant source of physical variability in the system; and (4) predictions about the effects of long-term climate change on animals at middle and upper trophic levels may be misleading if future levels of fishing are not considered. 37 refs., 4 tabs., 7 figs.

  2. A geochemical comparison of alkalic lavas in the Trans-Mexican Volcanic Belt, peninsular Baja California and intraplate volcanoes in the eastern Pacific

    Science.gov (United States)

    Tian, L.; Castillo, P. R.

    2011-12-01

    The Trans-Mexican Volcanic Belt (TMVB) is a continental volcanic arc built along the southern edge of the North American plate. The volcanic rocks along TMVB are compositionally diverse and the origin of its alkalic lavas with ocean island basalt (OIB)-like composition is highly controversial. Alkalic lavas from four regions in the western, central, and eastern TMVB [e.g., Verma and Hasenaka, Geochem. J., 58, 2004; Petrone et al., Geol. S. Am. S., 402, 2006; Orozco-Esquivel et al., Geol. Soc. Amer. Bull., 93, 2007] are compared with similar OIB-like alkalic lavas from peninsular Baja California [e.g., Storey et al., Terra Nova, 1, 1989; Castillo, Geol. Soc. Amer. Bull., 120, 2008] and intraplate volcanoes in the eastern Pacific [Tian et al., Geochem. Geophys. Geosyst., 12, 2011] in order to ascertain their geochemical similarities and differences and to constrain the compositions of their respective magma sources. A few of the alkalic lavas from TMVB have very similar trace element and isotopic compositions as the OIB-like alkalic lavas from peninsular Baja California and intraplate volcanoes in the eastern Pacific. Majority of the TMVB alkalic lavas, however, are compositionally more heterogeneous, similar to the less-alkalic Nb-enriched basalts in peninsular Baja California representing OIB-like alkalic lavas that had been contaminated by other mantle components and/or crustal materials. Thus, data seem to indicate that all the OIB-like alkalic lavas can be traced to a similar source, the compositionally heterogeneous Pacific asthenosphere.

  3. The presence of the Indo-Pacific symbiont-bearing foraminifer Amphistegina lobifera in Greek coastal ecosystems (Aegean Sea, Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    M.V. TRIANTAPHYLLOU

    2009-12-01

    Full Text Available During the last decades, hundreds of species of Indo-Pacific origin from the Red Sea have traversed the Suez Canal and settled in the Eastern Mediterranean. Nowadays, Amphistegina lobifera Larsen, is known to be a successful immigrant that is widely distributed in the coastal ecosystems of the Eastern Mediterranean Sea. Amphistegina is the most common epiphytic, symbiont- bearing large foraminifer. In this study we provide additional data on the presence of this species in the coastal ecosystems of Aegean Sea, Greece. The high relative abundance of A. lobifera is the result of very successful adaptation of this species to local conditions and suggests that it has become a significant part of the epiphytic foraminiferal fauna.

  4. Drought variability in the eastern Australia and New Zealand summer drought atlas (ANZDA, CE 1500-2012) modulated by the Interdecadal Pacific Oscillation

    Science.gov (United States)

    Palmer, Jonathan G.; Cook, Edward R.; Turney, Chris S. M.; Allen, Kathy; Fenwick, Pavla; Cook, Benjamin I.; O'Donnell, Alison; Lough, Janice; Grierson, Pauline; Baker, Patrick

    2015-12-01

    Agricultural production across eastern Australia and New Zealand is highly vulnerable to drought, but there is a dearth of observational drought information prior to CE 1850. Using a comprehensive network of 176 drought-sensitive tree-ring chronologies and one coral series, we report the first Southern Hemisphere gridded drought atlas extending back to CE 1500. The austral summer (December-February) Palmer drought sensitivity index reconstruction accurately reproduces historically documented drought events associated with the first European settlement of Australia in CE 1788, and the leading principal component explains over 50% of the underlying variance. This leading mode of variability is strongly related to the Interdecadal Pacific Oscillation tripole index (IPO), with a strong and robust antiphase correlation between (1) eastern Australia and the New Zealand North Island and (2) the South Island. Reported positive, negative, and neutral phases of the IPO are consistently reconstructed by the drought atlas although the relationship since CE 1976 appears to have weakened.

  5. Observations of heterogeneous reactions between Asian pollution and mineral dust over the Eastern North Pacific during INTEX-B

    Directory of Open Access Journals (Sweden)

    F. Flocke

    2009-11-01

    Full Text Available In-situ airborne measurements of trace gases, aerosol size distributions, chemistry and optical properties were conducted over Mexico and the Eastern North Pacific during MILAGRO and INTEX-B. Heterogeneous reactions between secondary aerosol precursor gases and mineral dust lead to sequestration of sulfur, nitrogen and chlorine in the supermicrometer particulate size range.

    Simultaneous measurements of aerosol size distributions and weak-acid soluble calcium result in an estimate of 11 wt% of CaCO3 for Asian dust. During transport across the North Pacific, ~5–30% of the CaCO3 is converted to CaSO4 or Ca(NO32 with an additional ~4% consumed through reactions with HCl. The 1996 to 2008 record from the Mauna Loa Observatory confirm these findings, indicating that, on average, 19% of the CaCO3 has reacted to form CaSO4 and 7% has reacted to form Ca(NO32 and ~2% has reacted with HCl. In the nitrogen-oxide rich boundary layer near Mexico City up to 30% of the CaCO3 has reacted to form Ca(NO32 while an additional 8% has reacted with HCl.

    These heterogeneous reactions can result in a ~3% increase in dust solubility which has an insignificant effect on their optical properties compared to their variability in-situ. However, competition between supermicrometer dust and submicrometer primary aerosol for condensing secondary aerosol species led to a 25% smaller number median diameter for the accumulation mode aerosol. A 10–25% reduction of accumulation mode number median diameter results in a 30–70% reduction in submicrometer light scattering at relative humidities in the 80–95% range. At 80% RH submicrometer light scattering is only reduced ~3% due to a higher mass fraction of hydrophobic refractory components in the dust-affected accumulation mode aerosol. Thus reducing the geometric mean diameter of

  6. On the role of mesoscale eddies for the biological productivity and biogeochemistry in the eastern tropical Pacific Ocean off Peru

    Directory of Open Access Journals (Sweden)

    L. Stramma

    2013-06-01

    Full Text Available Mesoscale eddies seem to play an important role for both the hydrography and biogeochemistry of the eastern tropical Pacific Ocean (ETSP off Peru. However, detailed surveys of these eddies are not available, which has so far hampered an in depth understanding of their implications for nutrient distribution and biological productivity. In this study three eddies along a section at 16°45' S have been surveyed intensively during R/V Meteor cruise M90 in November 2012. A coastal mode water eddy, an open ocean mode water eddy and an open ocean cyclonic eddy have been identified and sampled in order to determine both their hydrographic properties and their influence on the biogeochemical setting of the ETSP. In the thermocline the temperature of the coastal anticyclonic eddy was up to 2 °C warmer, 0.2 more saline and the swirl velocity was up to 35 cm s–1. The observed temperature and salinity anomalies, as well as swirl velocities of both types of eddies were about twice as large as had been described for the mean eddies in the ETSP and the observed heat and salt anomalies (AHA, ASA show a much larger variability than the mean AHA and ASA. We found that the eddies contributed significantly to productivity by maintaining pronounced subsurface maxima of chlorophyll. Based on a comparison of the coastal (young mode water eddy and the open ocean (old mode water eddy we conclude that the aging of eddies when they detach from the coast and move westward to the open ocean considerably influences the eddies' properties: chlorophyll maxima are weaker and nutrients are subducted. The coastal mode water eddy was found to be a hotspot of nitrogen loss in the OMZ, whereas, the open ocean cyclonic eddy was of negligible importance for nitrogen loss. Our results show that the important role the eddies play in the ETSP can only be fully deciphered and understood through dedicated high spatial and temporal resolution oceanographic/biogeochemical surveys.

  7. Food-web inferences of stable isotope spatial patterns in copepods and yellowfin tuna in the pelagic eastern Pacific Ocean

    Science.gov (United States)

    Olson, Robert J.; Popp, Brian N.; Graham, Brittany S.; López-Ibarra, Gladis A.; Galván-Magaña, Felipe; Lennert-Cody, Cleridy E.; Bocanegra-Castillo, Noemi; Wallsgrove, Natalie J.; Gier, Elizabeth; Alatorre-Ramírez, Vanessa; Ballance, Lisa T.; Fry, Brian

    2010-07-01

    Evaluating the impacts of climate and fishing on oceanic ecosystems requires an improved understanding of the trophodynamics of pelagic food webs. Our approach was to examine broad-scale spatial relationships among the stable N isotope values of copepods and yellowfin tuna ( Thunnus albacares), and to quantify yellowfin tuna trophic status in the food web based on stable-isotope and stomach-contents analyses. Using a generalized additive model fitted to abundance-weighted-average δ 15N values of several omnivorous copepod species, we examined isotopic spatial relationships among yellowfin tuna and copepods. We found a broad-scale, uniform gradient in δ 15N values of copepods increasing from south to north in a region encompassing the eastern Pacific warm pool and parts of several current systems. Over the same region, a similar trend was observed for the δ 15N values in the white muscle of yellowfin tuna caught by the purse-seine fishery, implying limited movement behavior. Assuming the omnivorous copepods represent a proxy for the δ 15N values at the base of the food web, the isotopic difference between these two taxa, “ ΔYFT-COP,” was interpreted as a trophic-position offset. Yellowfin tuna trophic-position estimates based on their bulk δ 15N values were not significantly different than independent estimates based on stomach contents, but are sensitive to errors in the trophic enrichment factor and the trophic position of copepods. An apparent inshore-offshore, east to west gradient in yellowfin tuna trophic position was corroborated using compound-specific isotope analysis of amino acids conducted on a subset of samples. The gradient was not explained by the distribution of yellowfin tuna of different sizes, by seasonal variability at the base of the food web, or by known ambit distances (i.e. movements). Yellowfin tuna stomach contents did not show a regular inshore-offshore gradient in trophic position during 2003-2005, but the trophic

  8. Particle optical backscattering along a chlorophyll gradient in the upper layer of the eastern South Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Y. Huot

    2007-12-01

    Full Text Available The particulate scattering, bp, and backscattering, bbp, coefficients are determined by the concentration and physical properties of suspended particles in the ocean. They provide a simple description of the influence of these particles on the scattering of light within the water column. For the remote observation of ocean color, bbp along with the total absorption coefficient govern the amount and spectral qualities of light leaving the sea surface. However, for the construction and validation of ocean color models measurements of bbp are still lacking, especially at low chlorophyll a concentrations ([Chl]. Here, we examine the relationships between spectral bbp and bp vs. [Chl] along an 8000 km transect crossing the Case 1 waters of the eastern South Pacific Gyre. In these waters, over the entire range of [Chl] encountered (~0.02–2 mg m−3, both bbp and bp can be related to [Chl] by power functions (i.e. bp or bbp=α[Chl]β Regression analyses are carried out to provide the parameters α and β for several wavelengths throughout the visible for both bbp and bp. When applied to the data, these functions retrieve the same fraction of variability in bbp and bp (determination coefficients between 0.82 and 0.88. The bbp coefficient fall within the bounds of previous measurements at intermediate and high [Chl] recently published. Its dependence on [Chl] below ~0.1 mg m−3 is described for the first time with in situ data. At these low and decreasing [Chl] a continuous trend with data at higher [Chl] is observed, i.e. a decrease in bbp. The backscattering ratio (i.e. bbp/bp with values

  9. An ecosystem services perspective for the oceanic eastern tropical Pacific: commercial fisheries, carbon storage, recreational fishing, and biodiversity

    Directory of Open Access Journals (Sweden)

    Summer Lynn Martin

    2016-04-01

    Full Text Available The ocean provides ecosystem services (ES that support humanity. Traditional single-issue management largely failed to protect the full suite of ES. Ecosystem-based management (EBM promotes resilient social-ecological systems that provide ES. To implement EBM, an ES approach is useful: 1 characterize major ES provided (magnitude, geographic extent, monetary value, trends, and stakeholders, 2 identify trade-offs, 3 determine desired outcomes, and 4 manage anthropogenic activities accordingly. Here we apply the ES approach (steps 1-2 to an open ocean ecosystem, the eastern tropical Pacific (ETP, an area of 21 million km2 that includes waters of 12 nations and the oceanic commons, using 35 years (1975-2010 of fisheries and economic data, and 20 years (1986-2006 of ship-based survey data. We examined commercial fisheries, carbon storage, biodiversity, and recreational fishing as the major provisioning, regulating, supporting, and cultural ES, respectively. Average catch value (using U.S. import prices for fish for the 10 most commercially fished species was $2.7 billion yr-1. The value of carbon export to the deep ocean was $12.9 billion yr-1 (using average European carbon market prices. For two fisheries-depleted dolphin populations, the potential value of rebuilding carbon stores was $1.6 million (cumulative; for exploited fish stocks it was also $1.6 million (an estimated reduction of 544,000 mt. Sport fishing expenditures totaled $1.2 billion yr-1, from studies of three popular destinations. These initial, conservative estimates do not represent a complete summary of ETP ES values. We produced species richness maps for cetaceans, seabirds, and ichthyoplankton, and a sightings density map for marine turtles. Over 1/3 of cetacean, seabird, and marine turtle species occur in the ETP, and diversity (or density hotspots are widespread. This study fills several gaps in the assessment of marine and coastal ES by focusing on an oceanic habitat

  10. Inaugural Asia-Pacific Dialogue on Clean Energy Governance, Policy, and Regulation: Sharing New Ideas for Asia Clean Energy Future

    OpenAIRE

    Asian Development Bank (ADB)

    2010-01-01

    In response to the growing demand of energy policy makers and regulators in the Asia and Pacific region for additional knowledge support on clean energy, this publication—prepared under the Law and Policy Reform Program of the Office of the General Counsel—presents lessons learned from countries’ clean energy policy and regulatory measures and approaches discussed during the Inaugural Asia-Pacific Dialogue on Clean Energy Governance, Policy, and Regulation held on 21–22 June 2010 at the Asian...

  11. Connection between interannual variability of the western Pacific and eastern Indian Oceans in the 1997~1998 El Ni(n)o event

    Institute of Scientific and Technical Information of China (English)

    WANG Dongxiao; LIU Qinyan; LIU Yun; SHI Ping

    2004-01-01

    In this paper,the sea surface height and the heat content of the upper ocean are analyzed to retrieve the relationship of interannual variabilities between the tropical western Pacific and eastern Indian Oceans during the 1997~1998 El Ni(n)o event.In the prophase of this El Ni(n)o,the negative sea level anomalies (SLA) occurred in the tropical western Pacific (TWP) firstly,and then appeared in the tropical eastern Indian Ocean (TEI).The negative heat content anomalies (HCA) emerged in the TWP before this El Nio burst while the SLA signals developed over there.During the mature stage of this El Ni(n)o,two kinds of signals in the TWP and TEI turned to be the maximum negative sequently.Due to the connected interannual adjustment between the TEI and TWP,we adopted a method to estimate the Indonesian Throughflow (ITF) transport by calculating the HCA budget in the TEI.The indirect estimation of the ITF was comparable to the observation values.Therefore,the anomalies in the TEI had been proved as advecting from the TWP through the ITF during the 1997~1998 El Ni(n)o.

  12. Comparative analysis of depth distribution for seventeen large pelagic fish species captured in a longline fishery in the central-eastern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Jiangfeng Zhu

    2012-02-01

    Full Text Available The objective of this study was to estimate depth distribution of pelagic species captured in a longline fishery and to evaluate the difference in depth distribution among species. We estimated depth distribution for 17 frequently captured species based on a Chinese longline fishing trip targeting bigeye tuna (Thunnus obesus in the central-eastern Pacific Ocean in February-November 2006. The depth distributions of 13 bycatch species were significantly different from that of bigeye tuna. Although most of the bycatch species were found to be distributed in water depths shallower than bigeye tuna (i.e. increasing hook depths can decrease catch rates of these species, the rates of catch rates declined with increasing hook depths may be different. The depth distributions were found to be not significantly different between genders for 7 species. There was no significant correlation between fish sizes and capture depths. The information derived from this study can play an important role in reducing bycatch in pelagic tuna longline fisheries in the central-eastern Pacific Ocean.

  13. Hydrothermal versus active margin sediment supply to the eastern equatorial Pacific over the past 23 million years traced by radiogenic Pb isotopes: Paleoceanographic and paleoclimatic implications

    Science.gov (United States)

    Höfig, Tobias W.; Hoernle, Kaj; Hauff, Folkmar; Frank, Martin

    2016-10-01

    We investigated the evolution of the Pb isotopic composition of bulk sediments on the Cocos Plate in sedimentary successions of Deep Sea Drilling Project (DSDP) Site 495 and Ocean Drilling Program/Integrated Ocean Drilling Program (ODP/IODP) Site 1256 over the past 23 million years of depositional history. Our study addresses the relationship of the sediment Pb isotope record to plate tectonics, weathering inputs, and paleoceanography. It is the first effort to characterize the Pb isotopic evolution of eastern equatorial Pacific sedimentation covering the entire tectonic pathway of the Cocos Plate from its formation at the East Pacific Rise to its arrival at the Central American subduction zone. The Sites 495 and 1256 bulk sediment Pb isotope records are fully consistent over time despite distinct differences between the type of sediment deposited at both locations. A systematic and continuous trend from ∼23 to ∼6-4 Ma toward more radiogenic Pb isotopic compositions, e.g., 206Pb/204Pb ratios increase from 18.29 to 18.81, reflects a decrease in the contribution of hydrothermal particles from the East Pacific Rise and an increase in the predominantly eolian contribution of mixed weathering products from the continental arcs of the Northern and south Central Andes as well as from southern Mexico. Surprisingly, both the Pb isotopic composition of the detrital fraction and that of past seawater indicate that inputs from nearby Central America and the Galápagos Archipelago did not significantly contribute to the sediments of our core locations but were overwhelmed by other sediment sources. A systematic change to less radiogenic Pb isotope ratios in sediments younger than ∼4-3 Ma, reaching present-day 206Pb/204Pb values near 18.70, reflects a reduction of the continental input from the South Central Volcanic Zone of the Andean Arc and increased contributions from southern Mexican igneous complexes. This isotopic trend reversal took place as a consequence of

  14. Determining bathymetric distributions of the eelgrass Zostera marina L. in three turbid estuaries of the eastern North Pacific coast

    Science.gov (United States)

    Improved methods for determining bathymetric distributions of dominant intertidal plants throughout their estuarine range are needed. Zostera marina is a seagrass native to estuaries of the northeastern Pacific and many other sectors of the world ocean. The technique described ...

  15. Southern Ocean influence on the eastern tropical North Pacific's intermediate-depth circulation during the Last Glacial Maximum

    OpenAIRE

    Carriquiry, José; Sanchez, Alberto; Leduc, Guillaume

    2015-01-01

    International audience; The oxygen and carbon isotopic compositions of benthic foraminiferal tests were measured on sedimentary sequences retrieved on the Magdalena Margin, off southern Baja California, Mexico. We reconstruct the hydrographic changes along the water column that occurred in the northeastern tropical Pacific since the Last Glacial Maximum (LGM) and compare those changes to the ones that occurred in the northwest Pacific (NWP, i.e., off Japan and Russia), in the northeast Pacifi...

  16. Strong Input and Removal of Rare Earth Elements (REEs) Affect Dissolved Nd Isotope Composition of Seawater in the Panama Basin and the Eastern Equatorial Pacific

    Science.gov (United States)

    Frank, M.; Bosse, L. M.; Grasse, P.; Pahnke, K.; Hathorne, E. C.

    2014-12-01

    The distributions of dissolved REEs and Nd isotopes are controlled by inputs from land and water mass mixing. We present new data from the Panama Basin in the Eastern Equatorial Pacific (EEP) extending previous studies in the frame of the German SFB 754 project. The samples were taken following GEOTRACES protocols along a section from close to the Panamanian coast into the deep Panama Basin during FS Meteor cruise M90 in October/November 2012. Elevated Nd concentrations near 13 pmol/kg are found at the surface, which rapidly decrease to a subsurface minimum of 8 pmol/kg near 100m depth and then increase with water depth reaching maximum values of 18 pmol/kg at 3000 m water depth. However, these deep water concentrations are more than a factor of 2 lower than observed for North Pacific Deep Water (NPDW), which is the prevailing Pacific deep water mass at the sampling locations. All the REEs are depleted compared to NPDW suggesting that efficient uptake and scavenging dominate compared to release from remineralized particles. The surface waters show the most radiogenic Nd isotope values (ɛNd = +4.3) so far obtained globally. In combination with the Nd concentration maxima at the surface this suggests riverine dissolved and fine grained particulate inputs from southern Panama and Colombia where highly radiogenic volcanic rocks are exposed. Elevated ɛNd values above -1 in the entire water column are more radiogenic than in NPDW in the Central Pacific and in waters further south in the EEP, which confirms that release of REEs from the sinking volcanogenic material affects the entire water column. These data clearly document that significant inputs from land combined with efficient scavenging and removal in surface and deep waters control the distribution of REEs and Nd isotopes in the Panama Basin and the adjacent EEP (Grasse et al., 2012), which also has important implications for the distribution of other trace metals.

  17. Mid-term coral-algal dynamics and conservation status of a Gorgona Island (Tropical Eastern Pacific coral reef

    Directory of Open Access Journals (Sweden)

    Fernando A Zapata

    2010-05-01

    Full Text Available Colombian coral reefs, as other reefs worldwide, have deteriorated significantly during the last few decades due to both natural and anthropogenic disturbances. The National Monitoring System for Coral Reefs in Colombia (SIMAC was established in 1998 to provide long-term data bases to assess the changes of Colombian coral reefs against perturbations and to identify the factors responsible for their decline or recovery. On the Pacific coast, data on coral and algal cover have been collected yearly during seven consecutive years (1998-2004 from 20 permanent transects in two sites at La Azufrada reef, Gorgona Island. Overall, coral cover was high (55.1%-65.7% and algal cover low (28.8%-37.5% and both exhibited significant changes among years, most notably on shallow areas. Differences between sites in both coral and algal cover were present since the study began and may be explained by differences in sedimentation stress derived from soil runoff. Differences between depths most likely stem from the effects of low tidal sub-aerial exposures. Particularly intense sub-aerial exposures occurred repeatedly during January-March, 2001 and accounted for a decrease in coral and an increase in algal cover on shallow depths observed later that year. Additionally, the shallow area on the Northern site seems to be negatively affected by the combined effect of sedimentation and low tidal exposure. However, a decrease in coral cover and an increase of algal cover since 2001 on deep areas at both sites remain unexplained. Comparisons with previous studies suggest that the reef at La Azufrada has been more resilient than other reefs in the Tropical Eastern Pacific (TEP, recovering pre-disturbance (1979 levels of coral cover within a 10 year period after the 1982-83 El Niño, which caused 85% mortality. Furthermore, the effects of the 1997-98 El Niño, indicated by the difference in overall live coral cover between 1998 and 1999, were minor (A través del Sistema

  18. Atmospheric salt deposition in a tropical mountain rain forest at the eastern Andean slopes of South Ecuador – Pacific or Atlantic origin?

    Directory of Open Access Journals (Sweden)

    S. Makowski Giannoni

    2015-10-01

    is below 10 %. This highlights the great importance of westerly winds from the Pacific for the sea-salt transport to the deposition into the tropical mountain forests at the eastern Andean slopes of southern Ecuador.

  19. A comparative Study of manufacturing industrial Competitiveness in eastern coastal provinces and cities of China based on shift-share analysis model

    Institute of Scientific and Technical Information of China (English)

    Yuan Aizhi

    2009-01-01

    Manufacturing industry is an important symbol which weighs a local economy comprehensive strength and modernized level, and a mighty manufacturing industry is a reliable guarantee which realizes the industry modernization.The manufacturing industry in eastern coastal provinces and cities of China, including Shandong, Jiangsu Zhejiang, Shanghai and Guangdong, holds a quite high proportion, and is competitive.But as to the interior, the manufacturing industry competitiveness of five provinces and cities actually has obviously gradient difference.The concrete profession's competitiveness also has the characteristic respectively.This paper analyzes the competitiveness of manufacturing industry in five provinces and cities by the shift-share analysis, obtains a conclusion that Shandong and Zhejiang have the competitive advantage in the traditional manufacturing industry, that Jiangsu's and Guangdong's competitiveness lies in capital, technology-intensive industry, but that Shanghai manufacturing industry's competitive advantage is not obvious, and then proposes strategy to promote the manufacturing industry in the eastern coastal provinces and cities.

  20. Nitrogen and oxygen isotopic composition of N sub(2)O from suboxic waters of the eastern tropical North Pacific and the Arabian Sea - measurement by continuous-flow isotope-ratio monitoring

    Digital Repository Service at National Institute of Oceanography (India)

    Yoshinari, T.; Altabet, M.A.; Naqvi, S.W.A.; Codispoti, L.; Jayakumar, D.A.; Kuhland, M.; Devol, A.

    and of the dual stable isotopic composition of N sub(2)O in the eastern tropical North Pacific (ETNP) and the Arabian Sea. The stable isotopic composition of N sub(2)O was determined by a new method that required only 80-100 nmol of N sub(2)O per sample analysis...

  1. Pacific Flyway management plan for Pacific brant

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Pacific Flyway brant (Branta bernicla) population (PFBP) is made up of brant breeding in Alaska, the western Canadian arctic, and the eastern Russian arctic, and...

  2. Prolonged El Niño conditions in 2014-2015 and the rapid intensification of Hurricane Patricia in the eastern Pacific

    Science.gov (United States)

    Foltz, Gregory R.; Balaguru, Karthik

    2016-10-01

    Hurricane Patricia was the most intense tropical cyclone on record in the eastern North Pacific or Atlantic, reaching a peak intensity of 95 m s-1 only 30 h after attaining hurricane status (33 m s-1). Here it is shown that exceptionally warm sea surface temperatures (SSTs), a deeper than normal thermocline, and strong near-surface salinity stratification all aided Patricia's rapid intensification, combining to increase its Potential Intensity by 1-14 m s-1. Anomalous surface warming and thermocline deepening along Patricia's track were driven by prolonged El Niño conditions during 2014-2015 and punctuated by the buildup to the extreme El Niño of 2015-2016. In the region where Patricia intensified, SST was 1.5° C higher and sea surface height was 10 cm higher compared to conditions during the last extreme El Niño in 1997, emphasizing the extraordinary nature of the 2015 anomalies.

  3. Comparison of eastern tropical Pacific TEX86 and Globigerinoides ruber Mg/Ca derived sea surface temperatures: Insights from the Holocene and Last Glacial Maximum

    Science.gov (United States)

    Hertzberg, Jennifer E.; Schmidt, Matthew W.; Bianchi, Thomas S.; Smith, Richard W.; Shields, Michael R.; Marcantonio, Franco

    2016-01-01

    The use of the TEX86 temperature proxy has thus far come to differing results as to whether TEX86 temperatures are representative of surface or subsurface conditions. In addition, although TEX86 temperatures might reflect sea surface temperatures based on core-top (Holocene) values, this relationship might not hold further back in time. Here, we investigate the TEX86 temperature proxy by comparing TEX86 temperatures to Mg/Ca temperatures of multiple species of planktonic foraminifera for two sites in the eastern tropical Pacific (on the Cocos and Carnegie Ridges) across the Holocene and Last Glacial Maximum. Core-top and Holocene TEX86H temperatures at both study regions agree well, within error, with the Mg/Ca temperatures of Globigerinoides ruber, a surface dwelling planktonic foraminifera. However, during the Last Glacial Maximum, TEX86H temperatures are more representative of upper thermocline temperatures, and are offset from G. ruber Mg/Ca temperatures by 5.8 °C and 2.9 °C on the Cocos Ridge and Carnegie Ridge, respectively. This offset between proxies cannot be reconciled by using different TEX86 temperature calibrations, and instead, we suggest that the offset is due to a deeper export depth of GDGTs at the LGM. We also compare the degree of glacial cooling at both sites based on both temperature proxies, and find that TEX86H temperatures greatly overestimate glacial cooling, especially on the Cocos Ridge. This study has important implications for applying the TEX86 paleothermometer in the eastern tropical Pacific.

  4. Investigations of (Delta)14C, (delta)13C, and (delta)15N in vertebrae of white shark (Carcharodon carcharias) from the eastern North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, L A; Andrews, A H; Cailliet, G M; Brown, T A; Coale, K H

    2006-06-08

    The white shark (Carcharodon carcharias) has a complex life history that is characterized by large scale movements and a highly variable diet. Estimates of age and growth for the white shark from the eastern North Pacific Ocean indicate they have a slow growth rate and a relatively high longevity. Age, growth, and longevity estimates useful for stock assessment and fishery models, however, require some form of validation. By counting vertebral growth band pairs, ages can be estimated, but because not all sharks deposit annual growth bands and many are not easily discernable, it is necessary to validate growth band periodicity with an independent method. Radiocarbon ({sup 14}C) age validation uses the discrete {sup 14}C signal produced from thermonuclear testing in the 1950s and 1960s that is retained in skeletal structures as a time-specific marker. Growth band pairs in vertebrae, estimated as annual and spanning the 1930s to 1990s, were analyzed for {Delta}{sup 14}C and stable carbon and nitrogen isotopes ({delta}{sup 13}C and {delta}{sup 15}N). The aim of this study was to evaluate the utility of {sup 14}C age validation for a wide-ranging species with a complex life history and to use stable isotope measurements in vertebrae as a means of resolving complexity introduced into the {sup 14}C chronology by ontogenetic shifts in diet and habitat. Stable isotopes provided useful trophic position information; however, validation of age estimates was confounded by what may have been some combination of the dietary source of carbon to the vertebrae, large-scale movement patterns, and steep {sup 14}C gradients with depth in the eastern North Pacific Ocean.

  5. Transformation from Paleo-Asian Ocean closure to Paleo-Pacific subduction: New constraints from granitoids in the eastern Jilin-Heilongjiang Belt, NE China

    Science.gov (United States)

    Ma, Xing-Hua; Zhu, Wen-Ping; Zhou, Zhen-Hua; Qiao, Shi-Lei

    2017-08-01

    The eastern Jilin-Heilongjiang Belt (EJHB) of NE China is a unique orogen that underwent two stages of evolution within the tectonic regimes of the Paleo-Asian and Paleo-Pacific oceans. 158 available zircon U-Pb ages, including 26 ages obtained during the present study and 132 ages from the literature, were compiled and analyzed for the Mesozoic and Cenozoic granitoids from the EJHB and the adjacent Russian Sikhote-Alin Orogenic Belt (SAOB), to examine the temporal-spatial distribution of the granitoids and to constrain the tectonic evolution of the East Asian continental margin. Five stages of granitic magmatism can be identified: Early Triassic (251-240 Ma), Late Triassic (228-215 Ma), latest Triassic to Middle Jurassic (213-158 Ma), Early Cretaceous (131-105 Ma), and Late Cretaceous to Paleocene (95-56 Ma). The Early Triassic granitoids are restricted to the Yanbian region along the Changchun-Yanji Suture, and show geochemical characteristics of magmas from a thickened lower crust source, probably due to the final collision of the combined NE China blocks with the North China Craton. The Late Triassic granitoids, with features of A-type granites, represent post-collisional magmatic activities that were related to post-orogenic extension, marking the end of the tectonic evolution of the Paleo-Asian Ocean. The latest Triassic to Paleocene granitoids with calc-alkaline characteristics were NE-trending emplaced along the EJHB and SAOB and young towards the coastal region, and represent continental marginal arc magmas that were associated with the northwestwards subduction of the Paleo-Pacific Plate. Two periods of magmatic quiescence (158-131 and 105-95 Ma) correspond to changes in the subduction direction of the Paleo-Pacific Plate from oblique relative to the continental margin to subparallel. Taking all this into account, we conclude that: (1) the final closure of the Paleo-Asian Ocean occurred along the Changchun-Yanji Suture during the Early Triassic; (2) the

  6. Surviving a High Nutrient-Low Chlorophyll (HNLC) region: insights to the internal cycling of nitrogen and iron in the eastern equatorial Pacific

    Science.gov (United States)

    Rafter, P. A.; Mackey, K. R.; Rykaczewski, R. R.; Sigman, D. M.

    2016-02-01

    The marine nutrient nitrate is completely utilized in much of the global surface ocean, but persists in so-called High-Nutrient, Low chlorophyll (HNLC) regions where primary production is limited by iron. Accordingly, the addition of iron to equatorial Pacific HNLC waters increases nitrate utilization and therefore decreases nitrate concentrations [NO3-]. However, seasonal variability in HNLC surface [NO3-] occurs alongside changes in upper ocean upwelling and stratification despite little seasonality in the flux of iron. Here we use nitrate isotopes (δ15N and δ18O) to show that seasonal variability of eastern equatorial Pacific HNLC surface [NO3-] is caused by changes in the degree of nitrate utilization that cannot be explained by the available iron flux. The available iron can account for less than 3 μmol/kg of nitrate utilization (19% of source water [NO3-]) even though the observed nitrate drawdown ranges from 7 μmol/kg (during boreal fall when upwelling is strongest) to >11 μmol/kg (during boreal spring when upwelling is weakest). Based on these observations, we propose that the photosynthetic picoplankton (e.g., Prochlorococcus and Synechococcus) with a low iron / carbon requirement preferentially consume recycled N compounds and that much of the recycled iron fuels nitrate assimilation by larger phytoplankton (e.g., diatoms). Slower upwelling rates during boreal spring and El Niño events therefore allow for more internal cycling of iron and increased nitrate utilization, explaining the seasonal variability in surface nitrate concentrations.

  7. Vertical thermal gradient history in the eastern equatorial Pacific during the early to middle Miocene: Implications for the equatorial thermocline development

    Science.gov (United States)

    Matsui, Hiroki; Nishi, Hiroshi; Kuroyanagi, Azumi; Hayashi, Hiroki; Ikehara, Minoru; Takashima, Reishi

    2017-07-01

    Knowledge of the equatorial thermocline is essential for understanding climate changes in the tropical Pacific. Multispecies planktic foraminiferal analyses provide a way to examine temperature distributions and thus the structure of the thermocline. Although the secular thermocline development has been documented back to the late Miocene, the early to middle Miocene interval has rarely been examined. In addition, relationships with the dynamic Antarctic ice sheets remain unclear. Here we investigate the vertical thermal gradient in the upper water column at Integrated Ocean Drilling Program Site U1337 in the eastern equatorial Pacific (EEP) throughout the early to middle Miocene (23.1 to 11.7 Ma). The gradient increased over the Miocene Climatic Optimum, whereas it decreased during the East Antarctic Ice Sheet Expansion (EAIE). Comparison of the EEP record with its western equatorial Pacific (WEP) counterpart suggests that sea surface temperature was more stable in the WEP than in the EEP. We further estimated equatorial thermocline from two diagonal gradients between the EEP and the WEP: thermocline shoaled from 16.7 to 15.7 Ma and tilt weakened between 16.5 and 13.8 Ma. The onset of the "Monterey Excursion" and the reduced Antarctic ice sheet volume would have affected thermocline depth and tilt, respectively. Thermocline depth was likely much deeper compared to Pliocene-to-modern conditions. Furthermore, a 4-point-based distribution of isotherms (4DI index) was used as a metric of the evenness or unevenness of the isotherm distributions. The 4DI index considerably reduced at around the EAIE and other Mi-events, reflecting the evenly distributed isotherms under a more glaciated Antarctica.

  8. Alkenone-based temperature patterns along the eastern South Pacific Coastal Ocean: the effect of upwelling and advection on the sedimentary alkenone unsaturation-index (U37K'

    Directory of Open Access Journals (Sweden)

    J. Garcés-Vargas

    2010-01-01

    Full Text Available We report that the sedimentary record of alkenone unsaturation-index (U37K' in the eastern South Pacific displays a wide range of temperatures, in response to sea surface temperature (SST, as well as nutrient concentrations. The U37K' inshore-offshore trend shows low-correlation with SSTs at many transitional sites (50–200 km offshore, and in one oligotrophic coastal site (~20° S. In contrast, in open-ocean sites SSTs play the expected dominant role. The latitudinal trend shows that nitrate, phosphate and/or temperature affect distinctively the U37K', suggesting progressive high-impacts in areas with permanent nutrient-stress conditions (~20° S, which is consistent with previous experiments. In contrast, this impact is slightly and not observable in transitional and open-ocean areas, respectively, where the coupling between offshore propagation of mesoscale eddies and upwelling filaments supply additional chlorophyll/nutrient. This study is a first field approximation to the impacts of thermal/non-thermal factors over the unsaturation-index in eastern Boundary Current systems, which would help in future temperature reconstructions.

  9. La Niña-like conditions in the eastern equatorial Pacific and a stronger Choco jet in the northern Andes during the last glaciation

    Science.gov (United States)

    MartíNez, Ignacio; Keigwin, Lloyd; Barrows, Timothy T.; Yokoyama, Yusuke; Southon, John

    2003-06-01

    Six deep sea cores from the eastern equatorial Pacific (EEP) were analyzed for planktonic foraminifera and stable isotopes in order to reconstruct sea surface temperatures (SST) for the last 40 ka. South of the Equatorial Front the abundance of Globorotalia inflata increased, and SST decreased by >5°C (core ODP846B), creating a stronger SST meridional gradient and advection of the Peru Current than present for the ˜16-35 ka interval. A sharper SST meridional gradient forced stronger Choco jet events and a moisture increase in western Colombia, which supplied, through the San Juan River and the south-flowing equatorial and the Peru-Chile countercurrents, abundant hemipelagic quartz over the northern Peru basin (core TR163-31B). The Choco jet, and its associated mesoscale convective cells, provoked an increase in snow precipitation over the Central Cordillera of Colombia and the advance of the Murillo glacier. In synchrony with the intensified Choco jet events, the "dry island" effect over the Eastern Cordillera of Colombia intensified, and the level of Fuquene Lake dropped.

  10. Understanding Abrupt, Natural Climate Variability Post-Industrial Revolution from the Subtropical Eastern Pacific: A Novel High Resolution Alkenone-derived Sea Surface Temperature Record

    Science.gov (United States)

    Kelly, C. S.; O'Mara, N. A.; Herbert, T.; Abella-Gutiérrez, J. L.; Herguera, J. C.

    2015-12-01

    Despite the ocean's importance in global biogeochemical feedbacks and heat storage, there is still a paucity of decadally-resolved sea surface temperature (SST) records to complement lacustrine and dendrological records of recent paleoclimate. Natural climate variability on multidecadal timescales is dominated by internal ocean circulation dynamics and feedbacks, and it is therefore imperative to employ marine proxies to reconstruct high resolution climate change. The timescales of this ocean-induced natural climate variability can be broken down into a few characteristic climate modes. Pressing questions about these modes include their stationarity in frequency and amplitude over time, in addition to the hypothesis that anthropogenic climate change has altered their behavior in comparison to natural variability. To pursue these questions, we must discern and analyze suitable climate archives in regions where modes of interest dominate modern climate variability. The region of Baja California, Mexico exhibits exceptional teleconnection to the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). Local, dramatic effects of ENSO and PDO on the marine biology and economy underline the importance of regional paleoclimate records from the Baja peninsula. Here, we present a high-resolution alkenone-derived SST reconstruction from the Industrial Revolution through the year 2000 by analysis of laminated box and Kasten sediment cores at Site PCM 00-78 (25.18°N, 112.66°W) in the subtropical eastern Pacific at a depth of 540 meters. Our SST record corresponds with NOAA extended reconstructed sea surface temperature, providing a robust basis for organic geochemical marine climatic reconstructions on timescales usually accessible only through speleothems, coral density bands, tree rings, and the like. Accordingly, based on this comparison to the historical data we expect our SST record may provide a more robust record of inter and multidecadal

  11. Tracking blue whales in the eastern tropical Pacific with an ocean-bottom seismometer and hydrophone array.

    Science.gov (United States)

    Dunn, Robert A; Hernandez, Olga

    2009-09-01

    Low frequency northeastern Pacific blue whale calls were recorded near the northern East Pacific Rise (9 degrees N latitude) on 25 ocean-bottom-mounted hydrophones and three-component seismometers during a 5-day period (November 22-26, 1997). Call types A, B, C, and D were identified; the most common pattern being approximately 130-135 s repetitions of the AB sequence that, for any individual whale, persisted for hours. Up to eight individual blue whales were recorded near enough to the instruments to determine their locations and were tracked call-by-call using the B components of the calls and a Bayesian inversion procedure. For four of these eight whales, the entire call sequences and swim tracks were determined for 20-26-h periods; the other whales were tracked for much shorter periods. The eight whales moved into the area during a period of airgun activity conducted by the academic seismic ship R/V Maurice Ewing. The authors examined the whales' locations and call characteristics with respect to the periods of airgun activity. Although the data do not permit a thorough investigation of behavioral responses, no correlation in vocalization or movement with airgun activity was observed.

  12. Identifying shared genetic structure patterns among Pacific Northwest forest taxa: insights from use of visualization tools and computer simulations.

    Directory of Open Access Journals (Sweden)

    Mark P Miller

    Full Text Available BACKGROUND: Identifying causal relationships in phylogeographic and landscape genetic investigations is notoriously difficult, but can be facilitated by use of multispecies comparisons. METHODOLOGY/PRINCIPAL FINDINGS: We used data visualizations to identify common spatial patterns within single lineages of four taxa inhabiting Pacific Northwest forests (northern spotted owl: Strix occidentalis caurina; red tree vole: Arborimus longicaudus; southern torrent salamander: Rhyacotriton variegatus; and western white pine: Pinus monticola. Visualizations suggested that, despite occupying the same geographical region and habitats, species responded differently to prevailing historical processes. S. o. caurina and P. monticola demonstrated directional patterns of spatial genetic structure where genetic distances and diversity were greater in southern versus northern locales. A. longicaudus and R. variegatus displayed opposite patterns where genetic distances were greater in northern versus southern regions. Statistical analyses of directional patterns subsequently confirmed observations from visualizations. Based upon regional climatological history, we hypothesized that observed latitudinal patterns may have been produced by range expansions. Subsequent computer simulations confirmed that directional patterns can be produced by expansion events. CONCLUSIONS/SIGNIFICANCE: We discuss phylogeographic hypotheses regarding historical processes that may have produced observed patterns. Inferential methods used here may become increasingly powerful as detailed simulations of organisms and historical scenarios become plausible. We further suggest that inter-specific comparisons of historical patterns take place prior to drawing conclusions regarding effects of current anthropogenic change within landscapes.

  13. Contribution of petroleum-derived organic carbon to sedimentary organic carbon pool in the eastern Yellow Sea (the northwestern Pacific).

    Science.gov (United States)

    Kim, Jung-Hyun; Lee, Dong-Hun; Yoon, Suk-Hee; Jeong, Kap-Sik; Choi, Bohyung; Shin, Kyung-Hoon

    2017-02-01

    We investigated molecular distributions and stable carbon isotopic compositions (δ(13)C) of sedimentary n-alkanes (C15C35) in the riverbank and marine surface sediments to trace natural and anthropogenic organic carbon (OC) sources in the eastern Yellow Sea which is a river dominated marginal sea. Molecular distributions of n-alkanes are overall dominated by odd-carbon-numbered high molecular weight n-C27, n-C29, and n-C31. The δ(13)C signatures of n-C27, n-C29, and n-C31 indicate a large contribution of C3 gymnosperms as the main source of n-alkanes, with the values of -29.5 ± 1.3‰, -30.3 ± 2.0‰, and -30.0 ± 1.7‰, respectively. However, the contribution of thermally matured petroleum-derived OC to the sedimentary OC pool is also evident, especially in the southern part of the study area as shown by the low carbon preference index (CPI25-33, petroleum-induced OC on benthic food webs in this ecosystem. However, the relative proportions of the natural and petroleum-derived OC sources are not calculated due to the lack of biogeochemical end-member data in the study area. Hence, more works are needed to constrain the end-member values of the organic material supplied from the rivers to the eastern Yellow Sea and thus to better understand the source and depositional process of sedimentary OC in the eastern Yellow Sea. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Paleoceanography of the eastern equatorial Pacific over the past 4 million years and the geologic origins of modern Galápagos upwelling

    Science.gov (United States)

    Karnauskas, Kristopher B.; Mittelstaedt, Eric; Murtugudde, Raghu

    2017-02-01

    An isolated, volcanic archipelago at the confluence of several major ocean currents, the Galápagos Archipelago (GA) is among the most biologically diverse places on Earth. There remain many open questions concerning evolution and speciation in the GA, with the details of the geologic formation of the islands over the past millions of years representing a key source of uncertainty. Paleoceanographic sea surface temperature (SST) proxy records from the far eastern equatorial Pacific (EEP) indicate that the modern gradient of SST across the GA (the cross-island SST gradient, or CIΔT) emerged relatively abruptly ∼1.6 Ma. As the modern CI ΔT is the result of a blockage and subsequent upwelling of the Equatorial Undercurrent (EUC) by the GA, we infer from these paleoceanographic data that the modern period during which the GA is arranged such that the islands constitute a significant topographic barrier to the EUC began ∼1.6 Ma. An extensive suite of ocean circulation model experiments-new and previously published-confirms that the sign and magnitude of the change in CI ΔT captured in paleoceanographic records can be explained by the islands impinging upon the EUC. Implications for the geologic history of the Galápagos and related biogeographical questions are discussed. Additionally, these results suggest that investigations of the Pan-Pacific SST gradient (PPΔT) should use one of the available proxy sites in the EEP that is not influenced by regional, geologically forced oceanographic changes; such an analysis supports recent suggestions of a more gradual development of the modern PP ΔT over the Plio-Pleistocene.

  15. Decadal to centennial fluctuations in the intensity of the eastern tropical North Pacific oxygen minimum zone during the last 1200 years

    Science.gov (United States)

    Tems, Caitlin E.; Berelson, William M.; Thunell, Robert; Tappa, Eric; Xu, Xiaomei; Khider, Deborah; Lund, Steve; González-Yajimovich, Oscar; Hamann, Yvonne

    2016-08-01

    Oxygen minimum zones (OMZs), located below highly productive marine regions, are sites of microbially mediated denitrification and biogeochemical cycling that have global significance. The intensity of OMZs fluctuates naturally; however, the degree of these fluctuations and a comprehensive understanding of the factors that drive these fluctuations on decadal to centennial time scales is lacking. Our high-resolution (near-annual) record of δ15Nsed from laminated sediments at the Pescadero Slope in the Gulf of California (eastern tropical North Pacific) fluctuates between maximum values of 10.5‰ and minimum values of 8.0‰ over the past 1200 years. An analysis of the relationship between δ15NO3- and [O2] in the water column suggests that the observed range of δ15Nsed values is equivalent to an approximately 8 µM fluctuation in O2 content and that these changes can occur in less than 25 years. Our findings show that the OMZ typically intensifies quickly and contracts gradually; the average rate of OMZ intensification (-0.24 µM O2/yr) is twice as fast as the rate of OMZ reoxygenation. Spectral analyses of the δ15Nsed record and Br/Cl counts, with the latter are used as a proxy for organic carbon preservation, suggest that the Pacific Decadal Oscillation and the Suess (deVries) solar cycle (solar irradiance) may influence the intensity of the OMZ and carbon production/export during the late Holocene. Coherence between δ15Nsed and weight percent organic carbon also suggests that similar mechanisms influence both OMZ fluctuations and variation in organic carbon production/export.

  16. Atmospheric salt deposition in a tropical mountain rainforest at the eastern Andean slopes of south Ecuador - Pacific or Atlantic origin?

    Science.gov (United States)

    Makowski Giannoni, Sandro; Trachte, Katja; Rollenbeck, Ruetger; Lehnert, Lukas; Fuchs, Julia; Bendix, Joerg

    2016-08-01

    Sea salt (NaCl) has recently been proven to be of the utmost importance for ecosystem functioning in Amazon lowland forests because of its impact on herbivory, litter decomposition and, thus, carbon cycling. Sea salt deposition should generally decline as distance from its marine source increases. For the Amazon, a negative east-west gradient of sea salt availability is assumed as a consequence of the barrier effect of the Andes Mountains for Pacific air masses. However, this generalized pattern may not hold for the tropical mountain rainforest in the Andes of southern Ecuador. To analyse sea salt availability, we investigated the deposition of sodium (Na+) and chloride (Cl-), which are good proxies of sea spray aerosol. Because of the complexity of the terrain and related cloud and rain formation processes, sea salt deposition was analysed from both, rain and occult precipitation (OP) along an altitudinal gradient over a period between 2004 and 2009. To assess the influence of easterly and westerly air masses on the deposition of sodium and chloride over southern Ecuador, sea salt aerosol concentration data from the Monitoring Atmospheric Composition and Climate (MACC) reanalysis data set and back-trajectory statistical methods were combined. Our results, based on deposition time series, show a clear difference in the temporal variation of sodium and chloride concentration and Na+ / Cl- ratio in relation to height and exposure to winds. At higher elevations, sodium and chloride present a higher seasonality and the Na+ / Cl- ratio is closer to that of sea salt. Medium- to long-range sea salt transport exhibited a similar seasonality, which shows the link between our measurements at high elevations and the sea salt synoptic transport. Although the influence of the easterlies was predominant regarding the atmospheric circulation, the statistical analysis of trajectories and hybrid receptor models revealed a stronger impact of the north equatorial Atlantic, Caribbean

  17. Significant impact of the East Asia monsoon on ozone seasonal behavior in the boundary layer of Eastern China and the west Pacific region

    Science.gov (United States)

    He, Y. J.; Uno, I.; Wang, Z. F.; Pochanart, P.; Li, J.; Akimoto, H.

    2008-12-01

    The impact of the East Asia monsoon on the seasonal behavior of O3 in the boundary layer of Eastern China and the west Pacific region was analyzed for 2004-2006 by means of full-year nested chemical transport model simulations and continuous observational data obtained from three inland mountain sites in central and eastern China and three oceanic sites in the west Pacific region. The basic common features of O3 seasonal behaviors over all the monitoring sites are the pre- and post-monsoon peaks with a summer trough. Such bimodal seasonal patterns of O3 are predominant over the region with strong summer monsoon penetration, and become weaker or even disappear outside the monsoon region. The seasonal/geographical distribution of the pre-defined monsoon index indicated that the East Asia summer monsoon is responsible for the bimodal seasonal O3 pattern, and also partly account for the differences in the O3 seasonal variations between the inland mountain and oceanic sites. Over the inland mountain sites, the O3 concentration increased gradually from the beginning of the year, reached a maximum in June, decreased rapidly to the summer valley in July or August, and then peaked in September or October, thereafter decreased gradually again. Over the oceanic sites, O3 abundance showed a similar increasing trend beginning in January, but then decreased gradually from the end of March, followed by a wide trough with the minimum in July and August and a small peak in October or November. A sensitivity analysis performed by setting China-emission to zero revealed that the chemically produced O3 from China-emission contributed substantially to the O3 abundance, particularly the pre- and post-monsoon O3 peaks, over China mainland. We found that China-emission contributed more than 40% to total boundary layer O3 during summertime (60-70% in July) and accounted for about 40 ppb of each peak value over the inland region if without considering the effect of the nonlinear chemical

  18. Primary productivity, nutrients, and other data from bottle casts in the Eastern Subarctic Pacific from the ENDEAVOUR and other platforms as part of the Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 01 July 1958 to 25 July 1974 (NODC Accession 7601768)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary productivity, nutrients, and other data were collected from bottle casts in the Eastern Subarctic Pacific from the ENDEAVOUR and other platforms from 01 July...

  19. Phytoplankton and other data from net and bottle casts in the Eastern Subarctic Pacific from the OREGON MAIL and other platforms as part of Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 26 June 1960 to 04 July 1972 (NODC Accession 7601829)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Phytoplankton and other data were collected from net and bottle casts in the Eastern Subarctic Pacific from the OREGON MAIL and other platforms from 26 June 1960 to...

  20. The true identity of Siderastrea glynni Budd & Guzmán, 1994, a highly endangered eastern Pacific scleractinian coral

    Science.gov (United States)

    Glynn, Peter W.; Grassian, Benjamin; Kleemann, Karl H.; Maté, Juan L.

    2016-12-01

    Siderastrea glynni Budd & Guzmán, 1994 was erroneously erected from live colonies of S. siderea (Ellis & Solander, 1768) unintentionally transferred from the Caribbean to the Pacific side of the Isthmus of Panamá. These corals had been used in experiments conducted in the early 1980s by KH Kleemann at Urabá Island, Taboga Islands, Gulf of Panamá, at the same site of the subsequent S. glynni discovery. Here, we offer evidence that live fragments deposited at Urabá Island in 1982 are the same found by Guzmán in 1992, and were inadvertently introduced from colonies of Caribbean S. siderea that were presumed to be dead. This morphological study builds on and supports recent genetic analyses of the S. glynni holobiont. In light of these findings, S. glynni should be regarded as a subjective junior synonym of S. siderea.

  1. New Miocene sulid birds from Peru and considerations on their Neogene fossil record in the Eastern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Marcelo Stucchi

    2016-06-01

    Full Text Available Boobies and gannets (family Sulidae are the most specialized plunge divers among seabirds. Their fossil record along the Pacific coast of South America extends to the early Middle Miocene. Here we describe three new species of sulids: Sula brandi sp. nov., Sula figueroae sp. nov., and Ramphastosula aguirrei sp. nov., from the early Late Miocene of the Pisco Formation (Peru. Two of them are relatives of the living genus Sula, which represents medium and large-sized boobies. A new species of the extinct genus Ramphastosula is also described, adding to the discussion of possible alternative feeding strategies among sulids. The fossil record suggests that sympatric sulids exhibit different body sizes at least since the Oligocene epoch, a strategy related with resource partitioning. Furthermore, we find current analysis and knowledge of the fossil record unsuitable to evaluate properly seabird diversity changes through time.

  2. DIAGNOSTIC PREDICTIONS OF SST IN THE EQUATORIAL EASTERN PACIFIC OCEAN BASED ON FUZZY INFERRING AND WAVELET DECOMPOSITION

    Institute of Scientific and Technical Information of China (English)

    张韧; 周林; 董兆俊; 李训强

    2002-01-01

    Methods and approaches are discussed that identify and filter off affecting factors (noise) above primary signals, based on the Adaptive-Network-Based Fuzzy Inference System. Influences of the zonal winds in equatorial castern and middle/western Pacific on the SSTA in the equatorial region and their contribution to the latter are diagnosed and verified with observations of a number of significant El Nino and La Nina episodes. New viewpoints are proposed. The method of wavelet decomposition and reconstruction are used to build a predictive model based on independent domains of frequency, which shows some advantages in composite prediction and prediction validity. The methods presented above are of non-linearity, error-allowing and auto-adaptive / learning.in addition to rapid and easy access, illustrative and quantitative presentation, and analyzed results that agree generally with facts. They are useful in diagnosing and predicting the El Nino and La Nina problems that are just roughly described in dynamics.

  3. Organic composition of single and submicron particles in different regions of western North America and the eastern Pacific during INTEX-B 2006

    Directory of Open Access Journals (Sweden)

    D. A. Day

    2009-08-01

    Full Text Available Single particles were collected from an aircraft platform as part of the Intercontinental Chemical Transport Experiment – Phase B (INTEX-B conducted over the eastern Pacific and western North America. Single particle spectra were obtained using scanning transmission X-ray microscopy-near edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS. Bulk submicron particles were also collected and organic functional group and elemental concentrations were quantified with Fourier transform infrared (FTIR spectroscopy and X-ray fluorescence (XRF. Single particle spectra were classified into metaclasses associated with different sources and atmospheric processing. Particles with spectra indicative of secondary organic aerosol production and combustion sources were found at several locations and a range of altitudes. At lower altitudes, particles with spectra resembling soil dust and biomass burning fingerprints were commonly observed. The types of particle spectra most commonly observed aloft were similar to those observed during a previous study over the northwestern Pacific, indicating that long-range transport may have been an important particle source. Single particle spectra provided evidence that condensation and surface-limited oxidation contributed to particle growth. Organic mass (OM concentrations ranged from 1 to 7 μg m−3 and averaged 2.4–4.1 μg m−3. Alkane functional groups were the largest fraction of OM, averaging 1.9–2.1 μg m−3 or 50–76% of OM, followed by alcohol functional groups (0.35–0.39 μg m−3, 9–14%. Organic and elemental concentrations are compared within and among geographical air mass regions: "Pacific" free troposphere, "Continental" free troposphere, "Seattle" metropolitan region, and the California "Central Valley". OM concentrations were highest and most variable in the Central Valley (3.5±2 μg m−3. Oxygen-to-carbon ratios were

  4. Box-modeling of the impacts of atmospheric nitrogen deposition and benthic remineralization on the nitrogen cycle of the eastern tropical South Pacific

    Directory of Open Access Journals (Sweden)

    B. Su

    2015-09-01

    Full Text Available Both atmospheric deposition and benthic remineralization influence the marine nitrogen cycle, and hence ultimately also marine primary production. The biological and biogeochemical relations of the eastern tropical South Pacific (ETSP to nitrogen deposition, benthic denitrification and phosphate regeneration are analysed in a prognostic box model of the oxygen, nitrogen and phosphorus cycles in the ETSP. In the model, atmospheric nitrogen deposition based on estimates for the years 2000–2009 is offset by half by reduced N2 fixation, with the other half transported out of the model domain. Both model- and data-based benthic denitrification are found to trigger nitrogen fixation, partly compensating for the NO3− loss. Since phosphate is the ultimate limiting nutrient in the model, enhanced sedimentary phosphate regeneration under suboxic conditions stimulates primary production and subsequent export production and NO3− loss in the oxygen minimum zone (OMZ. A sensitivity analysis of the local response to both atmospheric deposition and benthic remineralization indicates dominant stabilizing feedbacks in the ETSP, which tend to keep a balanced nitrogen inventory, i.e., nitrogen input by atmospheric deposition is counteracted by decreasing nitrogen fixation; NO3− loss via benthic denitrification is partly compensated by increased nitrogen fixation; enhanced nitrogen fixation stimulated by phosphate regeneration is partly removed by the stronger water-column denitrification. Even though the water column in our model domain acts as a NO3− source, the ETSP including benthic denitrification might become a NO3− sink.

  5. The 89 Ma Tortugal komatiitic suite, Costa Rica: Implications for a common geological origin of the Caribbean and Eastern Pacific region from a mantle plume

    Science.gov (United States)

    Alvarado, Guillermo E.; Denyer, Percy; Sinton, Christopher W.

    1997-05-01

    Komatiites are reported for the first time in the northern part of the Gulf of Nicoya, Costa Rica. These rocks, dated at 89.7 ± 1.4 Ma (Turonian) by 40Ar/39Ar methods, occur as a large, elongated (14 km long, 1.5 km wide) N60°W striking body in the ophiolitic Nicoya Complex. These lavas have high MgO (26% 29%), Ni, and Cr, have high CaO/Al2O3 (0.98 1.08) and moderate Al2O3/TiO2 (5.55 8.44) ratios, and are depleted in Al2O3 (4% 5.5%), K2O (0.02% 0.37%), and TiO2 (0.59% 0.9%). Although these lavas are cumulates, their geochemical composition indicates an origin from a primary komatiitic magma, with a melting temperature of 1700 °C at a depth of 150 km. Similarities in the petrology and age (88 90 Ma) of Gorgona, Curaìao, and Nicoya-Tortugal mafic and ultramafic volcanic rocks suggest that these rocks had a common origin. These occurrences suggest a single hotspot center over a large area of the Caribbean and Eastern Pacific Mesozoic region due to a major thermal anomaly in the mantle, such as a hot, rising, convective plume.

  6. The effect of nutrient supply ratios on organic matter dynamics, phytoplankton community composition and diazotrophy in the eastern tropical South Pacific

    Science.gov (United States)

    Meyer, J.; Lavik, G.; Riebesell, U.

    2015-12-01

    Upwelling of nutrient loaded water masses with low inorganic nitrogen (N) to phosphorus (P) ratios is thought to favor non-Redfield primary production by phytoplankton species adapted to exponential growth. Additionally, an excess of P (P*) in OMZ-influenced waters is also supposed to provide a niche for nitrogen fixing organisms. In order to assess the influence of low inorganic nutrient ratios on the stoichiometry and composition of primary producers, biogeochemical measurements were carried out in the eastern tropical South Pacific during R/V Meteor cruise M93. A succession of different functional types of phytoplankton was observed along onshore - offshore transects with diatoms dominating the productive upwelling region, while haptophytes, cryptophytes and crysophytes prevailed in the more oligotrophic open ocean. Simultaneously, particulate organic nitrogen to phosphorus ratios increased with increasing distance from shore. The stoichiometry of organic matter, however, always exceeded ratios of 16:1, although nutrient supply ratios were below Redfield proportions in the whole sampling area. A considerable amount of P* was detected in the surface ocean layer above the shelf, which decreased as water masses were advected beyond the shelf slope. Phytoplankton pigment analyses with HPLC revealed the existence of diazotrophic marker pigments in the study area, hinting towards a local replenishment of the N-deficit via nitrogen fixation.

  7. Intact polar lipids of Thaumarchaeota and anammox bacteria as indicators of N-cycling in the Eastern Tropical North Pacific oxygen deficient zone

    Directory of Open Access Journals (Sweden)

    M. Sollai

    2015-03-01

    Full Text Available In the last decade our understanding of the marine nitrogen cycle has improved considerably thanks to the discovery of two novel groups of microorganisms: ammonia-oxidizing archaea (AOA and anaerobic ammonia-oxidizing (anammox bacteria. Both groups are important in oxygen deficient zones (ODZs, where they substantially affect the marine N-budget. These two groups of microbes are also well known for producing specific membrane lipids, which can be used as biomarkers to trace their presence in the environment. We investigated the occurrence and distribution of AOA and anammox bacteria in the water column of the Eastern Tropical North Pacific (ETNP ODZ, one of the most prominent ODZs worldwide. Suspended particulate matter (SPM was collected at different depths of the water column in high resolution, at both a coastal and an open ocean setting. The SPM was analyzed for AOA- and anammox bacteria-specific intact polar lipids (IPLs, i.e. hexose-phosphohexose (HPH-crenarchaeol and phosphatidylcholine (PC-monoether ladderane. Comparison with oxygen profiles reveals that both the microbial groups are able to thrive at low (<1 μM concentrations of oxygen. Our results indicate a clear niche segregation of AOA and anammox bacteria in the coastal waters of the ETNP, but a partial overlap of the two niches of these microbial species in the open water setting. The latter distribution suggests the potential for an interaction between the two microbial groups at the open ocean site, either as competition or cooperation.

  8. Effect of Chlorophyll-a Spatial Distribution on Upper Ocean Temperature in the Central and Eastern Equatorial Pacific

    Institute of Scientific and Technical Information of China (English)

    LIN Pengfei; LIU Hailong; ZHANG Xuehong

    2008-01-01

    Effect of the spatial distributions of chlorophyll-a concentration on upper ocean temperature and currents in the equatorial Pacific is investigated through a set of numerical experiments by using an ocean general circulation model. This study indicates that enhanced meridional gradient of chlorophylloa between the equator and off-equatorial regions can strengthen zonal circulation and lead to a decrease in equatorial sea surface temperature (SST). However, the circulation changes by themselves are not effective enough to affect SST in the equatorial cold tongue (CT) region. The comparison between the experiments indicates that the CT SST are more sensitive to chlorophyll-a distribution away from the equator. The off-equatorial chlorophyll-a traps more solar radiation in the mixed layer, therefore, the temperature in the thermocline decreases. The cold water can then be transported to the equator by the meridional circulation within the mixed layer. Furthermore, the relation among CT SST, the surface heat flux, and the equatorial upwelling are discussed. The study implies the simulation biases of temperature on the equator are not only related to the local ocean dynamics but also related to some deficiency in simulating off-equatorial processes.

  9. Quantitation of persistent organic pollutants adsorbed on plastic debris from the Northern Pacific Gyre's "eastern garbage patch".

    Science.gov (United States)

    Rios, Lorena M; Jones, Patrick R; Moore, Charles; Narayan, Urja V

    2010-12-01

    Floating marine plastic debris was found to function as solid-phase extraction media, adsorbing and concentrating pollutants out of the water column. Plastic debris was collected in the North Pacific Gyre, extracted, and analyzed for 36 individual PCB congeners, 17 organochlorine pesticides, and 16 EPA priority PAHs. Over 50% contained PCBs, 40% contained pesticides, and nearly 80% contained PAHs. The PAHs included 2, 3 and 4 ring congeners. The PCBs were primarily CB-11, 28, 44, 52, 66, and 101. The pesticides detected were primarily p,p-DDTs and its metabolite, o,p-DDD, as well as BHC (a,b,g and d). The concentrations of pollutants found ranged from a few ppb to thousands of ppb. The types of PCBs and PAHs found were similar to those found in marine sediments. However, these plastic particles were mostly polyethylene which is resistant to degradation and although functioning similarly to sediments in accumulating pollutants, these had remained on or near the ocean surface. Particles collected included intact plastic items as well as many pieces less than 5 mm in size.

  10. Salinity minima, water masses and surface circulation in the Eastern Tropical Pacific off Mexico and surrounding areas

    Science.gov (United States)

    Portela, Esther; Beier, Emilio; Godínez, Victor; Castro, Rubén; Desmond Barton, Eric

    2016-04-01

    The seasonal variations of the water masses and their interactions are analyzed in the Tropical Pacific off Mexico (TPOM) and four contiguous areas of on the basis of new extensive hydrographic database. The regional water masses intervals are redefined in terms of Absolute Salinity (SA) in g kg-1 and Conservative Temperature (Θ) according to TEOS - 10. The California Current System Water (CCSW) mass is introduced as an improved description of the former California Current Water (CCW) together with the Subarctic Water (SAW) to describe better the characteristics of the components of the California Current System. Hydrographic data, Precipitation-Evaporation balance and geostrophic currents were used to investigate the origin and seasonality of two salinity minima in the area. The shallow salinity minimum of around 33.5 g kg-1 originated in the California Current System and became saltier but less dense water as it traveled to the southeast. It can be identified as a mixture of CCSW and tropical waters. The surface salinity minimum of 32 - 33 g kg-1 was seen as a sharp surface feature in the TPOM from August to November. It was produced by the arrival of tropical waters from the south in combination with the net precipitation in the area during these months. This result provides new evidence of the presence of the poleward-flowing Mexican Coastal Current and, for the first time, of its seasonal pattern of variation.

  11. Elasmobranchs observed in deepwaters (45-330m at Isla del Coco National Park, Costa Rica (Eastern Tropical Pacific

    Directory of Open Access Journals (Sweden)

    Jorge Cortés

    2012-11-01

    Full Text Available Isla del Coco is an oceanic island 500km off the Pacific coast of Costa Rica. It is a National Park and its marine fauna has been relatively well protected. The island is famous for its elasmobranch (sharks, rays and skates sightings in shallow waters. Here we present a catalogue of the deepwater elasmobranchs observed with the DeepSee submersible. Five species of sharks, six species of skates and one ray have been observed between 45 and 330m depth. Triaenodon obesus, the white tip reef shark, was commonly observed between 80 and 301m, but only in the afternoons. Sphyrna lewini, the scalloped hammerhead shark, was observed as deep a 303m, but commonly between 45 and 90m, and close to the island. Odontaspis ferox, the smalltooth sand tiger shark, was observed between 82 and 316m. Echinorhinus cookei, the prickly shark, was observed between 91 and 320m. Rhincodon typus, the whale shark, was observed only close to the island, between 77 and 80m. Taeniura meyeni, the marbled ray, was observed only close to the island, between 45 and 90m. A Dasyatis sp., similar to the the diamond stingray, was observed only once close to the island at 60m; this is the first report of this genus at Isla del Coco National Park. Manta birostris, the giant manta, was only observed close to the island at 90m. Mobula tarapacana, the sicklefin devil ray, was observed between 60 and 326m, extending its maximum depth almost 10 times what has been reported. Aetobatus narinari, the spotted eagle ray, was observed only close to the island between 60 and 82m. Torpedo peruana, the Peruvian torpedo ray, was observed only once at 313m, and is the first record of this species from Isla del Coco National Park.

  12. Physicochemical transition of long-range transport its effect on cloud condensation nuclei over the Eastern Pacific Ocean

    Science.gov (United States)

    Roberts, G.; Gilardoni, S.; Takahama, S.; Russell, L.; Tomlinson, J.; Collins, D.; Dunlea, E.; Jimenez, J.

    2007-05-01

    The Intercontinental Chemical Transport Experiment - Phase B (INTEX-B), which occurred in April 2006, focused on the transport and transformation of gases and aerosols on transcontinental and intercontinental scales to assess their impact on air quality and climate. Airborne measurements allow nearly complete characterization of the physicochemical properties of aerosol which allow an independent assessment of their mixing states and ability to act as cloud condensation nuclei (CCN). This chemical information, in conjunction with measurements of aerosol size distribution, investigates the concept of activation indices, which relate the efficiency of an aerosol to serve as CCN based on the relative amount of water-soluble material. During this experiment, we observed variety of aerosol layers during vertical and horizontal profiles, ranging from aged aerosols from major Asian dust storms to ultrafine particles from recent nucleation events. Aerosol layers observed during the flights were found in thin stratified layers ranging from altitudes of 1000 meters to 7000 meters and thicknesses from 100 to 1000 meters. Size resolved chemical measurements indicate cloud processed aerosol in the boundary layer and both aged and ultrafine layers aloft. Aerosols originating undergoing cloud processing activate close to the (NH4)2SO4 limit (activation index near unity); while those with anthropogenic origins show lower activation indices which points to an insoluble or hydrophobic core (i.e., biomass burning or dust) that has been aged by deposition of a water-soluble material. A comparison of the aerosol size distributions to the measured CCN concentration provides insight to the chemical evolution of the aerosols and their potential effect on aerosol/cloud interactions during long-range transport. In some cases, the aerosols have been transported across the Pacific without undergoing cloud processing. Research flight 5 was the first flight during INTEX-B that transected long

  13. Status of (137)Cs contamination in marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model two years simulation following the Fukushima accident.

    Science.gov (United States)

    Tateda, Yutaka; Tsumune, Daisuke; Tsubono, Takaki; Misumi, Kazuhiro; Yamada, Masatoshi; Kanda, Jota; Ishimaru, Takashi

    2016-01-01

    Radiocesium ((134)Cs and (137)Cs) released into the Fukushima coastal environment was transferred to marine biota inhabiting the Pacific Ocean coastal waters of eastern Japan. Though the levels in most of the edible marine species decreased overtime, radiocesium concentrations in some fishes were still remained higher than the Japanese regulatory limit for seafood products. In this study, a dynamic food chain transfer model was applied to reconstruct (137)Cs levels in olive flounder by adopting the radiocesium concentrations in small demersal fish which constitute an important fraction of the diet of the olive flounder particularly inhabiting area near Fukushima. In addition, (137)Cs levels in slime flounder were also simulated using reported radiocesium concentrations in some prey organisms. The simulated results from Onahama on the southern border of the Fukushima coastline, and at Choshi the southernmost point where the contaminated water mass was transported by the Oyashio current, were assessed in order to identify what can be explained from present information, and what remains to be clarified three years after the Fukushima Dai-ichi nuclear power plant (1FNPP) accident. As a result, the observed (137)Cs concentrations in planktivorous fish and their predator fish could be explained by the theoretically-derived simulated levels. On the other hand, the slow (137)Cs depuration in slime flounder can be attributed to uptake from unknown sources for which the uptake fluxes were of a similar magnitude as the excretion fluxes. Since the reported (137)Cs concentrations in benthic invertebrates off Onahama were higher than the simulated values, radiocesium transfer from these benthic detritivorous invertebrates to slime flounder via ingestion was suggested as a cause for the observed slow depuration of (137)Cs in demersal fish off southern Fukushima. Furthermore, the slower depuration in the demersal fish likely required an additional source of (137)Cs, i

  14. Ecological patterns, distribution and population structure of Prionace glauca (Chondrichthyes: Carcharhinidae) in the tropical-subtropical transition zone of the north-eastern Pacific.

    Science.gov (United States)

    Vögler, Rodolfo; Beier, Emilio; Ortega-García, Sofía; Santana-Hernández, Heriberto; Valdez-Flores, J Javier

    2012-02-01

    Regional ecological patterns, distribution and population structure of Prionace glauca were analyzed based on samples collected on-board two long-line fleets operating in oceanic waters (1994-96/2000-02) and in coastal oceanic waters (2003-2009) of the eastern tropical Pacific off México. Generalized additive models were applied to catch per unit of effort data to evaluate the effect of spatial, temporal and environmental factors on the horizontal distribution of the life stages (juvenile, adult) and the sexes at the estimated depth of catch. The presence of breeding areas was explored. The population structure was characterized by the presence of juveniles' aggregations and pregnant females towards coastal waters and the presence of adult males' aggregations towards oceanic waters. The species exhibited horizontal segregation by sex-size and vertical segregation by sex. Distribution of the sex-size groups at oceanic waters was seasonally affected by the latitude; however, at coastal oceanic waters mainly females were influenced by the longitude. Latitudinal changes on the horizontal distribution were coupled to the seasonal forward and backward of water masses through the study area. Adult males showed positive relationship with high temperatures and high-salinities waters (17.0°-20.0 °C; 34.2-34.4) although they were also detected in low-salinities waters. The distribution of juvenile males mainly occurred beyond low temperatures and low-salinities waters (14.0°-15.0 °C; 33.6-34.1), suggesting a wide tolerance of adult males to explore subartic and subtropical waters. At oceanic areas, adult females were aggregated towards latitudes glauca. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Poorly cemented coral reefs of the eastern tropical Pacific: possible insights into reef development in a high-CO2 world.

    Science.gov (United States)

    Manzello, Derek P; Kleypas, Joan A; Budd, David A; Eakin, C Mark; Glynn, Peter W; Langdon, Chris

    2008-07-29

    Ocean acidification describes the progressive, global reduction in seawater pH that is currently underway because of the accelerating oceanic uptake of atmospheric CO(2). Acidification is expected to reduce coral reef calcification and increase reef dissolution. Inorganic cementation in reefs describes the precipitation of CaCO(3) that acts to bind framework components and occlude porosity. Little is known about the effects of ocean acidification on reef cementation and whether changes in cementation rates will affect reef resistance to erosion. Coral reefs of the eastern tropical Pacific (ETP) are poorly developed and subject to rapid bioerosion. Upwelling processes mix cool, subthermocline waters with elevated pCO(2) (the partial pressure of CO(2)) and nutrients into the surface layers throughout the ETP. Concerns about ocean acidification have led to the suggestion that this region of naturally low pH waters may serve as a model of coral reef development in a high-CO(2) world. We analyzed seawater chemistry and reef framework samples from multiple reef sites in the ETP and found that a low carbonate saturation state (Omega) and trace abundances of cement are characteristic of these reefs. These low cement abundances may be a factor in the high bioerosion rates previously reported for ETP reefs, although elevated nutrients in upwelled waters may also be limiting cementation and/or stimulating bioerosion. ETP reefs represent a real-world example of coral reef growth in low-Omega waters that provide insights into how the biological-geological interface of coral reef ecosystems will change in a high-CO(2) world.

  16. Vertical modeling of the nitrogen cycle in the eastern tropical South Pacific oxygen deficient zone using high-resolution concentration and isotope measurements

    Science.gov (United States)

    Peters, Brian D.; Babbin, Andrew R.; Lettmann, Karsten A.; Mordy, Calvin W.; Ulloa, Osvaldo; Ward, Bess B.; Casciotti, Karen L.

    2016-11-01

    Marine oxygen deficient zones (ODZs) have long been identified as sites of fixed nitrogen (N) loss. However, the mechanisms and rates of N loss have been debated, and traditional methods for measuring these rates are labor-intensive and may miss hot spots in spatially and temporally variable environments. Here we estimate rates of heterotrophic nitrate reduction, heterotrophic nitrite reduction (denitrification), nitrite oxidation, and anaerobic ammonium oxidation (anammox) at a coastal site in the eastern tropical South Pacific (ETSP) ODZ based on high-resolution concentration and natural abundance stable isotope measurements of nitrate (NO3-) and nitrite (NO2-). These measurements were used to estimate process rates using a two-step inverse modeling approach. The modeled rates were sensitive to assumed isotope effects for NO3- reduction and NO2- oxidation. Nevertheless, we addressed two questions surrounding the fates of NO2- in the ODZ: (1) Is NO2- being primarily reduced to N2 or oxidized to NO3- in the ODZ? and (2) what are the contributions of anammox and denitrification to NO2- removal? Depth-integrated rates from the model suggest that 72-88% of the NO2- produced in the ODZ was oxidized back to NO3-, while 12-28% of NO2- was reduced to N2. Furthermore, our model suggested that 36-74% of NO2- loss was due to anammox, with the remainder due to denitrification. These model results generally agreed with previously measured rates, though with a large range of uncertainty, and they provide a long-term integrated view that compliments incubation experiments to obtain a broader picture of N cycling in ODZs.

  17. Box-modelling of the impacts of atmospheric nitrogen deposition and benthic remineralisation on the nitrogen cycle of the eastern tropical South Pacific

    Science.gov (United States)

    Su, Bei; Pahlow, Markus; Oschlies, Andreas

    2016-09-01

    Both atmospheric deposition and benthic remineralisation influence the marine nitrogen cycle, and hence ultimately also marine primary production. The biological and biogeochemical relations in the eastern tropical South Pacific (ETSP) among nitrogen deposition, benthic denitrification and phosphorus regeneration are analysed in a prognostic box model of the oxygen, nitrogen and phosphorus cycles in the ETSP. Atmospheric nitrogen deposition ( ≈ 1.5 Tg N yr-1 for the years 2000-2009) is offset by half in the model by reduced N2 fixation, with the other half transported out of the model domain. Model- and data-based benthic denitrification in our model domain are responsible for losses of 0.19 and 1.0 Tg Tg N yr-1, respectively, and both trigger nitrogen fixation, partly compensating for the NO3- loss. Model- and data-based estimates of enhanced phosphate release via sedimentary phosphorus regeneration under suboxic conditions are 0.062 and 0.11 Tg N yr-1, respectively. Since phosphate is the ultimate limiting nutrient in the model, even very small additional phosphate inputs stimulate primary production and subsequent export production and NO3- loss in the oxygen minimum zone (OMZ). A sensitivity analysis of the local response to both atmospheric deposition and benthic remineralisation indicates dominant stabilising feedbacks in the ETSP, which tend to keep a balanced nitrogen inventory; i.e. nitrogen input by atmospheric deposition is counteracted by decreasing nitrogen fixation; NO3- loss via benthic denitrification is partly compensated for by increased nitrogen fixation; enhanced nitrogen fixation stimulated by phosphate regeneration is partly counteracted by stronger water-column denitrification. Even though the water column in our model domain acts as a NO3- source, the ETSP including benthic denitrification might be a NO3- sink.

  18. Integrative taxonomy and molecular phylogeny of genus Aplysina (Demospongiae: Verongida from Mexican Pacific.

    Directory of Open Access Journals (Sweden)

    José Antonio Cruz-Barraza

    Full Text Available Integrative taxonomy provides a major approximation to species delimitation based on integration of different perspectives (e.g. morphology, biochemistry and DNA sequences. The aim of this study was to assess the relationships and boundaries among Eastern Pacific Aplysina species using morphological, biochemical and molecular data. For this, a collection of sponges of the genus Aplysina from the Mexican Pacific was studied on the basis of their morphological, chemical (chitin composition, and molecular markers (mitochondrial COI and nuclear ribosomal rDNA: ITS1-5.8-ITS2. Three morphological species were identified, two of which are new to science. A. clathrata sp. nov. is a yellow to yellow-reddish or -brownish sponge, characterized by external clathrate-like morphology; A. revillagigedi sp. nov. is a lemon yellow to green, cushion-shaped sometimes lobate sponge, characterized by conspicuous oscules, which are slightly elevated and usually linearly distributed on rims; and A. gerardogreeni a known species distributed along the Mexican Pacific coast. Chitin was identified as the main structural component within skeletons of the three species using FTIR, confirming that it is shared among Verongida sponges. Morphological differences were confirmed by DNA sequences from nuclear ITS1-5.8-ITS2. Mitochondrial COI sequences showed extremely low but diagnostic variability for Aplysina revillagigedi sp. nov., thus our results corroborate that COI has limited power for DNA-barcoding of sponges and should be complemented with other markers (e.g. rDNA. Phylogenetic analyses of Aplysina sequences from the Eastern Pacific and Caribbean, resolved two allopatric and reciprocally monophyletic groups for each region. Eastern Pacific species were grouped in general accordance with the taxonomic hypothesis based on morphological characters. An identification key of Eastern Pacific Aplysina species is presented. Our results constitute one of the first approximations

  19. A Record of the Eastern Tropical Pacific of Water Column Structure Reorganization during the Rapid Climate Changes of Marine Isotope Stage 3.

    Science.gov (United States)

    Hendy, I. L.

    2007-05-01

    Little is known about the details of paleoceanographic changes in the Eastern Tropical Pacific (ETP) during marine isotope stage 3. Here we present a high resolution record of climate change from core ME0005A 10JC (15.7°N; 95.3°E, 1040 m water depth) collected in the Gulf of Tehuantepec spanning 48 to 38 Ka. Planktonic and benthic stable isotope records have been generated alongside Corg, carbonate, δ15N and trace metal concentrations of bulk sediments. Seasonal intense wind forced upwelling produces high Corg flux in the Gulf. In winter, high atmospheric pressures in the Gulf of Mexico and low pressures in the ETP (associated with the ITCZ) create a strong pressure gradient generally blocked by high mountains along the isthmus. A gap near the Gulf of Tehuantepec allows air to spill over into the Pacific creating a hurricane force wind (the Tehuanos) that pushes water off the broad shelf, producing non-Ekman upwelling. Corg production increases from 48 to 38 Ka in association with increasing nitrate utilization as indicated by increasing δ15N values. Conservative trace metals increase relative to non-conservative between 45 and 43 Ka simultaneously with shift to more positive benthic δ13C, while non-conservative (nutrient- like) metals increase after 43 Ka. A prominent short ~1‰ negative shift in benthic δ18O occurs at 44.5 Ka with a 0.5‰ positive step occurring at 43.5 Ka. Globigerina ruber records δ18O values of ~-1‰ between 46 and 45 Ka, decreasing by ~1‰ at 45 Ka, while δ13C values vary between 0 and 1‰. Globigerina bulloides records δ18O values of ~0.5‰ and δ13C of 1‰ between 46 and 45 Ka, but records δ18O values of ~-1‰ and δ13C of -1‰ between 44 and 42 Ka. G. bulloides is associated with winter upwelling in the region, while G. ruber is a surface dweller associated with the Costa Rica Current that enters the Gulf in summer. Neogloboquadrina dutertrei and Globorotalia menardii generally record δ18O values of 0.5 to 0‰ and δ13

  20. Microbial sulfate reduction and the sulfur budget for a complete section of altered oceanic basalts, IODP Hole 1256D (eastern Pacific)

    Science.gov (United States)

    Alt, Jeffrey C.; Shanks, Wayne C.

    2011-01-01

    Sulfide mineralogy and the contents and isotope compositions of sulfur were analyzed in a complete oceanic volcanic section from IODP Hole 1256D in the eastern Pacific, in order to investigate the role of microbes and their effect on the sulfur budget in altered upper oceanic crust. Basalts in the 800m thick volcanic section are affected by a pervasive low-temperature background alteration and have mean sulfur contents of 530ppm, reflecting loss of sulfur relative to fresh glass through degassing during eruption and alteration by seawater. Alteration halos along fractures average 155ppm sulfur and are more oxidized, have high SO4/ΣS ratios (0.43), and lost sulfur through oxidation by seawater compared to host rocks. Although sulfur was lost locally, sulfur was subsequently gained through fixation of seawater-derived sulfur in secondary pyrite and marcasite in veins and in concentrations at the boundary between alteration halos and host rocks. Negative δ34Ssulfide-S values (down to -30 °) and low temperatures of alteration (down to ~40 °C) point to microbial reduction of seawater sulfate as the process resulting in local additions of sulfide-S. Mass balance calculations indicate that 15-20% of the sulfur in the volcanic section is microbially derived, with the bulk altered volcanic section containing 940ppm S, and with δ34S shifted to -6.0‰) from the mantle value (0 ‰). The bulk volcanic section may have gained or lost sulfur overall. The annual flux of microbial sulfur into oceanic basement based on Hole 1256D is 3-4 X1010molSyr-1, within an order of magnitude of the riverine sulfate source and the sedimentary pyrite sink. Results indicate a flux of bacterially derived sulfur that is fixed in upper ocean basement of 7-8 X 10-8molcm-2yr-1 over 15m.y. This is comparable to that in open ocean sediment sites, but is one to two orders of magnitude less than for ocean margin sediments. The global annual subduction of sulfur in altered oceanic basalt lavas based

  1. Early diagenetic quartz formation at a deep iron oxidation front in the Eastern Equatorial Pacific - A modern analogue for banded iron/chert formations?

    Science.gov (United States)

    Meister, Patrick; Chapligin, Bernhard; Picard, Aude; Meyer, Hanno; Fischer, Cornelius; Rettenwander, Daniel; Amthauer, Georg; Vogt, Christoph; Aiello, Ivano W.

    2014-07-01

    The mechanisms of early diagenetic quartz formation under low-temperature conditions are still poorly understood. In this study we investigated lithified cherts consisting of microcrystalline quartz recovered near the base of a 420 m thick Miocene-Holocene sequence of nannofossil and diatom ooze at a drill site in the Eastern Equatorial Pacific (Ocean Drilling Program Site 1226). Precipitation seems still ongoing based on a sharp depletion in dissolved silica at the depth of the cherts. Also, palaeo-temperatures reconstructed from δ18O values in the cherts are in the range of adjacent porewater temperatures. Opal-A dissolution appears to control silica concentration throughout the sequence, while the solution remains oversaturated with respect to quartz. However, at the depth of the sharp depletion in dissolved silica, quartz is still saturated while the more soluble silica phases are strongly undersaturated. Hence, precipitation of quartz was initiated by an auxiliary process. A process, previously observed to assist in the nucleation of quartz is the adsorption of silica on freshly precipitated iron oxides. Indeed, a deep iron oxidation front is present at 400 m below seafloor, which is caused by upward diffusing nitrate from an oxic seawater aquifer in the underlying oceanic crust. Sequential iron extraction showed a higher content of the adsorbed iron hydroxide fraction in the chert than in the adjacent nannofossil and diatom ooze. X-ray absorption near-edge structure (XANES) spectroscopy revealed that iron in the cherts predominantly occurs in illite and amorphous iron oxide, whereas iron in the nannofossil and diatom ooze occurs mainly in smectite. Mössbauer spectroscopy also indicated the presence of illite that is to 97% oxidized. Two possible mechanisms may be operative during early diagenetic chert formation at iron oxidation fronts: (1) silica precipitation is catalysed by adsorption to freshly precipitated iron oxide surfaces, and (2) porewater silica

  2. TIPEX (Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment Program

    Directory of Open Access Journals (Sweden)

    Dongchull Jeon

    2013-09-01

    Full Text Available One of the factors influencing the climate around Korea is the oceanic-atmospheric variability in the tropical region between the eastern Indian and the western Pacific Oceans. Lack of knowledge about the air-sea interaction in the tropical Indo-Pacific region continues to make it problematic forecasting the ocean climate in the East Asia. The ‘Tropical Indo-Pacific water transport and ecosystem monitoring EXperiment (TIPEX’ is a program for monitoring the ocean circulation variability between Pacific and Indian Oceans and for improving the accuracy of future climate forecasting. The main goal of the TIPEX program is to quantify the climate and ocean circulation change between the Indian and the Pacific Oceans. The contents of the program are 1 to observe the mixing process of different water masses and water transport in the eastern Indian and the western Pacific, 2 to understand the large-scale oceanic-climatic variation including El Niño-Southern Oscillation (ENSO/Warm Pool/Pacific Decadal Oscillation (PDO/Indian Ocean Dipole (IOD, and 3 to monitor the biogeochemical processes, material flux, and biological changes due to the climate change. In order to effectively carry out the monitoring program, close international cooperation and the proper co-work sharing of tasks between China, Japan, Indonesia, and India as well as USA is required.

  3. Conservation Genetics of the Scalloped Hammerhead Shark in the Pacific Coast of Colombia.

    Science.gov (United States)

    Quintanilla, Sonia; Gómez, Alberto; Mariño-Ramírez, Camila; Sorzano, Carolina; Bessudo, Sandra; Soler, German; Bernal, Jaime E; Caballero, Susana

    2015-01-01

    Previous investigations of the population genetics of the scalloped hammerhead sharks (Sphyrna lewini) in the Eastern Tropical Pacific have lacked information about nursery areas. Such areas are key to promoting conservation initiatives that can protect young sharks from threats such as overfishing. Here, we investigated the genetic diversity, phylogeography, and connectivity of S. lewini found in 3 areas of Colombia's Pacific coast: around Malpelo Island and in 2 National Natural Parks on the Colombian Pacific mainland (Sanquianga and Ensenada de Utría). We analyzed mtDNA control region (CR) sequences and genotyped 15 microsatellite loci in 137 samples of adults and juveniles. The mtDNA analyses showed haplotypes shared between the Colombian Pacific individuals sampled in this investigation and other areas in the Eastern Tropical Pacific, the Indo-Pacific, and with sequences previously reported in Colombia (Buenaventura Port), as well as 4 unique haplotypes. Population assignment and paternity analyses detected 3 parent-offspring pairs between Malpelo and Sanquianga and 1 between Malpelo and Utría. These results indicate high genetic connectivity between Malpelo Island and the Colombian Pacific coast, suggesting that these 2 areas are nurseries for S. lewini. This is, to our knowledge, the first evidence of nursery areas identified for the scalloped hammerhead shark anywhere in the world. Additional conservation planning may be required to protect these nursery habitats of this endangered shark species.

  4. Condiciones oceanográficas en isla Gorgona, Pacífico oriental tropical de Colombia Oceanographic conditions off Gorgona Island, eastern tropical Pacific of Colombia

    Directory of Open Access Journals (Sweden)

    Alan Giraldo

    2008-01-01

    Full Text Available La zona de influencia costera de isla Gorgona es un área marina protegida localizada en el Pacífico Oriental Tropical (POT de Colombia. Aunque alberga uno de los arrecifes coralinos más desarrollados del POT, la caracterización de las condiciones oceanógraficas superficiales locales y su variabilidad temporal y espacial han sido escasamente abordadas. Para incrementar el conocimiento sobre la variabilidad de la temperatura y la salinidad en esta localidad se realizaron registros sistemáticos de estas variables durante cuatro periodos (septiembre 2005, diciembre 2005, marzo 2006 y junio 2006, se instalaron sensores de registro continuo de temperatura a f 5 m de profundidad en la zona oriental y occidental de la isla, y se realizó un monitoreo del patrón local de circulación superficial utilizando un perfilador de corrientes (AWAK-ADCP durante junio 2006 y febrero 2007. Se identificaron dos períodos contrastantes para las condiciones oceanógraficas en la capa superficial (0-50 m de la columna de agua: un período cálido y de baja salinidad superficial entre mayo y diciembre (profundidad termoclina 47 m y un período frío y salino entre enero y abril (profundidad termoclina 7,5 m. Se descartó la presencia de proceso local de surgencia y los resultados indicaron una fuerte influencia de procesos de mesoescala (surgencia en el Panamá Bight sobre la variabilidad temporal de las condiciones oceanógraficas en la zona de estudio. En este mismo sentido se sugiere que la variabilidad espacial estaría más asociada a procesos climáticos regionales (patrón de precipitación y la cercanía de la zona de estudio al complejo deltaico río Patía - río Sanquianga.The near shore zone of Gorgona Island is a protected marine area located in the Eastern Tropical Pacific (ETP of Colombia. Although this is home to one of the most developed coral reefs in the ETP, the characteristics of the local oceanographic conditions at the surface and their

  5. Using Genome-Wide SNPs to Detect Structure in High-Diversity and Low-Divergence Populations of Severely Impacted Eastern Tropical Pacific Spinner (Stenella longirostris And Pantropical Spotted Dolphins (S. attenuata

    Directory of Open Access Journals (Sweden)

    Matthew Steven Leslie

    2016-12-01

    Full Text Available Millions of spinner (Stenella longirostris and pantropical spotted dolphins (Stenella attenuata died since the 1960’s as bycatch in tuna nets in the eastern tropical Pacific Ocean. Despite three decades of protection, they show little-to-no sign of recovery (although recent fisheries-independent abundance estimates are not available. In efforts to establish biologically meaningful management boundaries for recovery, endemic subspecies and multiple stocks have been proposed. However, genetic differentiation among most of these units has been difficult to identify, possibly due to low statistical power stemming from large historical abundances, ongoing gene flow, and recent divergence. We tested for genetic structure at multiple hierarchical levels by analyzing the largest dataset to date brought to bear on these questions. Single nucleotide polymorphisms (SNPs were collected from nuclear DNA regions associated with the restriction enzyme site PstI from 72 spinner dolphins and 58 pantropical spotted dolphins using genotype-by-sequencing (GBS. Our results support the current subspecies for both species and indicate stock-level separation for Tres Marias spinner dolphins and the two offshore pantropical spotted dolphin stocks in this area. Although bycatch has been reduced a small fraction of pre-protection levels, incidental mortality continues to impact these populations. Our results are important for the ongoing management and recovery of these highly-impacted pelagic dolphins in the eastern tropical Pacific Ocean.

  6. US Japan Alliance Confronts the Anti Access and Area Denial Challenge: Toward Building Capacity, Cooperation and Information Sharing in the Western Pacific

    Science.gov (United States)

    2015-01-01

    U.S. allies in the Pacific to bolster their side. Aaron Friedberg , a proponent of ASB, writes that frontline states in the Asia-Pacific such as Japan...Taiwan and the Philippines may not be reassured by a distant blockade. Friedberg argues that, “if China conquered Taiwan, or seized disputed islands... Friedberg , Beyond Air-Sea Battle: The Debate over US Military Strategy in Asia. April 2014 (New York, NY: Routledge, 2014), pp.15-21. iii Mark A. Stokes

  7. OCLC in Asia Pacific.

    Science.gov (United States)

    Chang, Min-min

    1998-01-01

    Discusses the Online Computer Library Center (OCLC) and the changing Asia Pacific library scene under the broad headings of the three phases of technology innovation. Highlights include WorldCat and the OCLC shared cataloging system; resource sharing and interlibrary loan; enriching OCLC online catalog with Asian collections; and future outlooks.…

  8. Dinámica de la flota atunera mexicana del Océano Pacífico Oriental Mexican tuna fleet dynamics of the Eastern Pacific Ocean

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    Rafael Solana-Sansores

    2009-12-01

    Full Text Available Se analiza la dinámica de la flota atunera mexicana del Pacífico Oriental y su relación con señales medioambientales utilizadas en las estrategias de pesca. La información proviene de una muestra sistemática con arranque aleatorio de 176 cruceros de pesca registrados por el programa mexicano de observadores, entre 1992 y 2005. En cada viaje la información se genera secuencialmente en lapsos de tiempo fijos, permitiendo suponer que los registros son un proceso estocástico discreto y puede analizarse como una Cadena de Markov. Los registros se agrupan en: (1 desplazamientos espaciales del barco; (2 observación de señales y (3 maniobras de pesca. En el análisis se reconocen dos tácticas de pesca: una sistemática y otra aleatoria. La primera inicia con una búsqueda de señales (aves o mamíferos marinos, seguido de un lance de pesca sobre cardúmenes asociados a delfines o sobre cardúmenes no asociados. Alternativamente, las tácticas aleatorias no involucran una búsqueda y llevan, con menor probabilidad, a un lance sobre atunes no asociados. Ambas tácticas de pesca son influenciados por factores ambientales, ecológicos, sociales, y económicos. De este modo se observan diferentes estrategias durante un ciclo anual o de mayor duración, que están relacionadas con políticas regionales de manejo pesquero derivadas del Acuerdo del Programa Internacional de Conservación de Delfines. Se concluye que la dinámica de la flota atunera mexicana es un factor que deberá analizarse sistemáticamente en la estimación del Esfuerzo de Pesca para obtener mejores evaluaciones de los rendimientos de esta pesquería.It analyzes the fishing dynamics of the Mexican tuna fleet of the Eastern Tropical Pacific (ETP and its relation with environmental signs which are used for fishing. The information comes from a systematic sample with a random start of 176 fishing cruisers, registered by the observer's Mexican program (1992 to 2005. In each trip the

  9. Variability in eastern equatorial Pacific intermediate water circulation during the last glacial termination: the impact of high latitude climate on equatorial stratification

    Science.gov (United States)

    Bova, S. C.; Herbert, T.; Mojarro, A.

    2013-12-01

    The eastern equatorial Pacific (EEP) is linked directly to the Southern High latitudes through an oceanic tunneling system that transports Antarctic Intermediate Water (AAIW) and Subantarctic Mode Water (SAMW) directly into the equatorial and Peru Margin upwelling systems (Toggweiler et al. 1991). These intermediate water masses form within the subantarctic zone and flow north, propagating signals of high latitude climate to the low latitude ocean (Kessler 2006). Their heat and salinity content are transported conservatively along their flow path and the high nutrient content of these waters support up to three-fourths of all biological production north of 30°S (Fiedler and Talley 2006, Sarmiento et al. 2004). Thus, variations in the physio-chemical properties and/or transport of these water masses into the low latitude thermocline have vast implications for oceanic heat transport, primary production, and global nutrient cycles (e.g CO2 and N). Here we assess the physio-chemical response of these Southern Ocean intermediate waters to high latitude forcing during the last glacial termination and the impact of these changes on EEP subsurface structure. Alkenone sea surface temperature reconstructions and benthic foraminiferal stable isotopic records from four rapidly accumulating sediment cores from the EEP cold tongue document variation in temperature and salinity gradients at three intermediate water depths (370, 600, and 1000 m). Our records provide evidence for substantial change in water column structure during the last glacial termination. Regional stratification decreased significantly during the deglacial (11-18 ka) relative to the last glacial period and the Holocene due to asynchronous warming of the EEP water column. Deglacial warming began first at 1000 m depth at ~18.2 ka, in phase with southern hemisphere temperatures, while surface warming experienced a 1-2 kyr delay. Additionally, we observe a convergence of oxygen and carbon isotopes across

  10. {sup 137}Cs, {sup 239+240}Pu and {sup 240}Pu/{sup 239}Pu atom ratios in the surface waters of the western North Pacific Ocean, eastern Indian Ocean and their adjacent seas

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masatoshi; Zheng, Jian; Wang, Zhong-Liang [Nakaminato Laboratory for Marine Radioecology, National Institute of Radiological Sciences, Isozaki 3609, Hitachinaka, Ibaraki 311-1202 (Japan)

    2006-07-31

    Surface seawater samples were collected along the track of the R/V Hakuho-Maru cruise (KH-96-5) from Tokyo to the Southern Ocean. The {sup 137}Cs activities were determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas, the eastern Indian Ocean, the Bay of Bengal, the Andaman Sea, and the South China Sea. The {sup 137}Cs activities showed a wide variation with values ranging from 1.1 Bq m{sup -3} in the Antarctic Circumpolar Region of the Southern Ocean to 3 Bq m{sup -3} in the western North Pacific Ocean and the South China Sea. The latitudinal distributions of {sup 137}Cs activity were not reflective of that of the integrated deposition density of atmospheric global fallout. The removal rates of {sup 137}Cs from the surface waters were roughly estimated from the two data sets of Miyake et al. [Miyake Y, Saruhashi K, Sugimura Y, Kanazawa T, Hirose K. Contents of {sup 137}Cs, plutonium and americium isotopes in the Southern Ocean waters. Pap Meteorol Geophys 1988;39:95-113] and this study to be 0.016 yr{sup -1} in the Sulu and Indonesian Seas, 0.033 yr{sup -1} in the Bay of Bengal and Andaman Sea, and 0.029 yr{sup -1} in the South China Sea. These values were much lower than that in the coastal surface water of the western Northwest Pacific Ocean. This was likely due to less horizontal and vertical mixing of water masses and less scavenging. {sup 239+240}Pu activities and {sup 240}Pu/{sup 239}Pu atom ratios were also determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas and the South China Sea. The {sup 240}Pu/{sup 239}Pu atom ratios ranged from 0.199+/-0.026 to 0.248+/-0.027 on average, and were significantly higher than the global stratospheric fallout ratio of 0.18. The contributions of the North Pacific Proving Grounds close-in fallout Pu were estimated to be 20% for the western North Pacific Ocean, 39% for the Sulu and Indonesian Seas and 42% for the South China Sea by using

  11. {sup 137}Cs, {sup 239+24}Pu and {sup 24}Pu/{sup 239}Pu atom ratios in the surface waters of the western North Pacific Ocean, eastern Indian Ocean and their adjacent seas

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masatoshi [Nakaminato Laboratory for Marine Radioecology, National Institute of Radiological Sciences, Isozaki 3609, Hitachinaka, Ibaraki 311-1202 (Japan)]. E-mail: m_yamada@nirs.go.jp; Zheng Jian [Nakaminato Laboratory for Marine Radioecology, National Institute of Radiological Sciences, Isozaki 3609, Hitachinaka, Ibaraki 311-1202 (Japan); Wang Zhongliang [Nakaminato Laboratory for Marine Radioecology, National Institute of Radiological Sciences, Isozaki 3609, Hitachinaka, Ibaraki 311-1202 (Japan); State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guanshui Road 46, Guiyang 550002 (China)

    2006-07-31

    Surface seawater samples were collected along the track of the R/V Hakuho-Maru cruise (KH-96-5) from Tokyo to the Southern Ocean. The {sup 137}Cs activities were determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas, the eastern Indian Ocean, the Bay of Bengal, the Andaman Sea, and the South China Sea. The {sup 137}Cs activities showed a wide variation with values ranging from 1.1 Bq m{sup -3} in the Antarctic Circumpolar Region of the Southern Ocean to 3 Bq m{sup -3} in the western North Pacific Ocean and the South China Sea. The latitudinal distributions of {sup 137}Cs activity were not reflective of that of the integrated deposition density of atmospheric global fallout. The removal rates of {sup 137}Cs from the surface waters were roughly estimated from the two data sets of Miyake et al. [Miyake Y, Saruhashi K, Sugimura Y, Kanazawa T, Hirose K. Contents of {sup 137}Cs, plutonium and americium isotopes in the Southern Ocean waters. Pap Meteorol Geophys 1988;39:95-113] and this study to be 0.016 yr{sup -1} in the Sulu and Indonesian Seas, 0.033 yr{sup -1} in the Bay of Bengal and Andaman Sea, and 0.029 yr{sup -1} in the South China Sea. These values were much lower than that in the coastal surface water of the western Northwest Pacific Ocean. This was likely due to less horizontal and vertical mixing of water masses and less scavenging. {sup 239+24}Pu activities and {sup 24}Pu/{sup 239}Pu atom ratios were also determined for the surface waters in the western North Pacific Ocean, the Sulu and Indonesian Seas and the South China Sea. The {sup 24}Pu / {sup 239}Pu atom ratios ranged from 0.199 {+-} 0.026 to 0.248 {+-} 0.027 on average, and were significantly higher than the global stratospheric fallout ratio of 0.18. The contributions of the North Pacific Proving Grounds close-in fallout Pu were estimated to be 20% for the western North Pacific Ocean, 39% for the Sulu and Indonesian Seas and 42% for the South China Sea by

  12. Seven new species of Paleanotus (Annelida: Chrysopetalidae) described from Lizard Island, Great Barrier Reef, and coral reefs of northern Australia and the Indo-Pacific: two cryptic species pairs revealed between western Pacific Ocean and the eastern Indian Ocean.

    Science.gov (United States)

    Watson, Charlotte

    2015-09-18

    Morphological investigation into the paleate genus Paleanotus Schmarda 1861 of the family Chrysopetalidae from northern Australian coral reefs, primarily Lizard Island and outlying reefs, included a complex of very small, slender individuals (length Great Barrier Reef to the Philippines, western Pacific Ocean. Cryptic morphology and potential genetic diversity is discussed in Paleanotus inornatus n. sp. and P. adornatus n. sp. that possess overlapping widespread distribution patterns across northern Australia and Indo-Pacific reefs. The smallest bodied taxon, Paleanotus chrysos n. sp. is the only species with a Coral Sea range encompassing Lizard Island, Heron Island and New Caledonia.

  13. Hipéridos (Crustacea: Amphipoda en el sector norte del Pacífico oriental tropical colombiano Hyperiids (Crustacea: Amphipoda along the northern margin of the eastern tropical Pacific of Colombia

    Directory of Open Access Journals (Sweden)

    Bellineth Valencia

    2009-01-01

    Full Text Available Con el objetivo de analizar la composición, abundancia y diversidad de la comunidad de anfipodos hipéridos en las localidades de Punta Cruces y Cabo Marzo, costa norte del Pacífico colombiano (Pacífico oriental tropical, se realizó una campaña de muestreo en enero de 2008 siguiendo una malla de nueve estaciones. Se encontró un total de 20 especies, siendo Lestrigonus bengalensis e Hyperioides sibaginis las más abundantes, representando el 91% de la comunidad en Cabo Marzo y el 95% de la comunidad en Punta Cruces. La abundancia y la diversidad en las dos localidades fueron muy variables, y no presentaron diferencias significativas (Mann Whitney; p > 0,05. Así mismo, se estableció que la similitud en términos de la composición y la abundancia entre las comunidades de hipéridos de Punta Cruces y Cabo Marzo fue de un 64,6%. Este trabajo proporciona información inédita sobre un componente poco estudiado del zooplancton en el Pacífico oriental tropical, incrementando el número de especies registradas para el Pacífico colombiano.In order to analyze the composition, abundance, and diversity of hyperiid amphipods at Punta Cruces and Cabo Marzo, on the northern Pacific coast of Colombia (eastern tropical Pacific, a sampling campaign was carried out in January 2008 that covered a nine-station sampling grid. Twenty species were found, of which Lestrigonus bengalensis and Hyperioides sibaginis were the most abundant (91% of the community at Cabo Marzo and 95% at Punta Cruces. Although the abundance and diversity were highly variable at both sites, they did not differ significantly (Mann Whitney; p > 0.05. Likewise, the similarity in terms of composition and abundance between the hyperiid communities at Punta Cruces and Cabo Marzo was 64.6%. This re-search provides new information regarding a scarcely studied component of the zooplankton in the eastern tropical Pacific and increases the number of hyperiid species reported for the Pacific

  14. Primary studies on the population genetic structure of Dosidicus gigas in the high seas of eastern Pacific Ocean%东太平洋公海茎柔鱼种群遗传结构初步研究

    Institute of Scientific and Technical Information of China (English)

    闫杰; 许强华; 陈新军; 李纲; 刘必林

    2011-01-01

    The jumbo flying squid(Dosidicus gigas)is commercially important fishery species in the world. Assessment of population genetic diversity levels of jumbo flying squid is fundamental to the conservation and management of this species. The samples derived from the Chinese squid jigging vessel were collected from the eastern Pacific waters(81.9°-94.9°W,8.9°N -11.3°S)from July to October 2009. By using 724 bp fragment of mitochondrial cytochrome b gene ( Cyt b), we analyzed the sequence variations and population genetic structures for 155 samples collected from seven sites of Peru and three sites of Costa Rica. In total, 16 variable sites were acquired, and all of them were parsimony sites. 43 haplotypes were identified from 155 individuals. Analysis of mtDNA Cyt b sequences of jumbo flying squids from the ten localities revealed that the mean haplotypic diversity was 0. 873, while the nucleotide diversity was 0.003 69. 6 haplotypes were shared by all the populations, while Peru population possessed the highest haplotypes (n = 20). The AMOVA test of D. Gigas revealed that 82. 70% of the genetic variation occurred within populations. FST analysis suggested that significant genetic differentiations were found between the partial Peru populations and the Costa Rica populations, and even between partial Peru populations. However, no significant genetic differentiations were detected between Costa Rica populations.%根据2009年7月到10月我国大型鱿钓渔船在东太平洋(81.9°~94.9°W,8.9°N~11.3°S)秘鲁和哥斯达黎加外海作业期间采集的样本,利用线粒体DNA细胞色素b基因的724 bp部分序列,分析了采自秘鲁7个采样点和哥斯达黎加3个采样点的155个个体的序列多样性与种群遗传结构.结果显示,724 bp片段中发现了16个变异位点,155个个体出现43个单倍型.序列多样性分析结果揭示,155个个体的平均单倍型多样性指数为0.873,核苷酸多样性指数为0.003 69.群体间共享6

  15. Marine turtles of the Gal?pagos Islands and adjacent areas of the eastern Pacific on the basis of observations made by J.R. Slevin 1905-1906

    Science.gov (United States)

    Fritts, T.H.

    1981-01-01

    The field notes of J. R. Slevin written during the expedition of the California Academy of Sciences to the Galapagos Islands in 1905-1096 contain previously unavailable data on the marine turtles of the eastern Pacific. 'Land basking' by green turtles in Galapagos was predominately, if not exclusively, a female behavior. These terrestrial emergences were not concentrated in the major reproductive season of Galapagos turtles. Female Chelonia were also collected on shore during daylight hours on Socorro Island southwest of Baja California, Mexico. Chelonia, green turtles, were observed to feed on seaweed, the leaves and shoots of mangrove trees, and the leaves of another unidentified shoreline shrub. Comparative data on the gonads of dark and yellow turtles indicated that the latter did not breed in Galapagos during Slevin's stay. Lepidochelys olivacea, the olive ridley, was recorded in Galapagos waters and fed on fish eggs

  16. Overlap of eastern and western mangroves in the South-western Pacific: hybridization of all three Rhizophora (Rhizophoraceae) combinations in New Caledonia

    NARCIS (Netherlands)

    Duke, N.C.

    2010-01-01

    A recent survey of mangroves in New Caledonia located 7 taxa of the genus Rhizophora – with 6 coexisting in one estuary. This is arguably the greatest concentration of co-occurring Rhizophora taxa anywhere. Two are well-known mangrove species of the Indo West Pacific, R. stylosa and R. apiculata,

  17. A comparison of visual and collection-based methods for assessing community structure of coral reef fishes in the Tropical Eastern Pacific

    NARCIS (Netherlands)

    Alzate, Adriana; Zapata, Fernando A.; Giraldo, Alan

    2014-01-01

    Gorgona Island, the major insular area in the Colombian Pacific Ocean, is characterized by a remarkably high biological and ecosystem diversity for this area of the world. Coral reefs are well developed and their fish communities have been described using conventional visual surveys. These methods,

  18. Paralarvae of the complex Sthenoteuthis oualaniensis-Dosidicus gigas (Cephalopoda: Ommastrephidae) in the northern limit of the shallow oxygen minimum zone of the Eastern Tropical Pacific Ocean (April 2012)

    Science.gov (United States)

    Sánchez-Velasco, Laura; Ruvalcaba-Aroche, Erick D.; Beier, Emilio; Godínez, Victor M.; Barton, Eric D.; Díaz-Viloria, Noe; Pacheco, María. R.

    2016-03-01

    The three-dimensional distribution of the paralarvae of the complex Sthenoteuthis oualaniensis-Dosidicus gigas (Cephalopoda: Ommastrephidae) was analyzed at the northern limit of the shallow oxygen minimum zone in the Eastern Tropical Pacific in April 2012. The upper limit of the oxygen minimum water (˜44 µmol/kg or 1 mL/L) rises from ˜100 m depth in the entrance of the Gulf of California to ˜20 m depth off Cabo Corrientes. Most of the paralarvae of this complex, dominated by D. gigas, were concentrated in the Gulf entrance, between the thermocline (˜20 to ˜50 m depth) and the sea surface, in the warmest (>19°C) oxygenated (>176 µmol/kg) layer. The highest abundance of paralarvae was detected in an anticyclonic eddy (˜120 km diameter and >500 m deep), which contained lower-salinity water (<35 g/kg), consistent with formation in the California Current. Lower paralarvae abundance was recorded further south off Cabo Corrientes, where hypoxic layers were elevated as water shoaled nearshore. Almost no paralarvae were found in the north of the study area beyond the strong salinity front (˜34.8-35.4 g/kg) that bounded the anticyclone. These results showed an affinity of the paralarvae for lower-salinity, oxygenated water, illustrated by the influence of the mesoscale anticyclonic eddy and the salinity front in their distribution. Based on this study, it can be concluded that the expansion of the depth range of hypoxic water observed in the Eastern Tropical Pacific may be increasing environmental stress on the paralarvae by vertically restricting their habitat, and so affecting their survival.

  19. Metal contents of marine turtle eggs (Chelonia mydas; Lepidochelys olivacea) from the tropical eastern pacific and the implications for human health.

    Science.gov (United States)

    Ross, David A; Guzmán, Héctor M; Van Hinsberg, Vincent J; Potvin, Catherine

    2016-10-02

    Concentrations of eight elements were measured in Chelonia mydas and Lepidochelys olivacea eggs collected along the Pacific coast of Panama. Manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), and mercury (Hg) concentrations were similar to previous reports of these species from around the world, while lead (Pb) was lower than previous reports. Cd posed the highest health risk to people who regularly eat the eggs, with average consumption rates leading to target hazard quotients (THQ) of up to 0.35 ± 0.15. Our conclusions indicate that current turtle egg consumption in isolated, coastal Pacific communities may pose a health concern for young children, and that youth and young adults should limit their consumption of turtle eggs to reduce their total intake of nonessential metals.

  20. Sharing values, sharing a vision

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    Teamwork, partnership and shared values emerged as recurring themes at the Third Technology Transfer/Communications Conference. The program drew about 100 participants who sat through a packed two days to find ways for their laboratories and facilities to better help American business and the economy. Co-hosts were the Lawrence Livermore National Laboratory and the Lawrence Berkeley Laboratory, where most meetings took place. The conference followed traditions established at the First Technology Transfer/Communications Conference, conceived of and hosted by the Pacific Northwest Laboratory in May 1992 in Richmond, Washington, and the second conference, hosted by the National Renewable Energy Laboratory in January 1993 in Golden, Colorado. As at the other conferences, participants at the third session represented the fields of technology transfer, public affairs and communications. They came from Department of Energy headquarters and DOE offices, laboratories and production facilities. Continued in this report are keynote address; panel discussion; workshops; and presentations in technology transfer.

  1. Expedition surveys of the sea water and atmospheric air radioactive contamination in the Russian Far Eastern coastal areas and in the North Western Pacific in connection with accident at the "Fukushima-1" NPP

    Science.gov (United States)

    Nikitin, Aleksandr; Shershakov, Vjacheslav

    2013-04-01

    In accordance with decision of the Russian Federation Federal Service on Hydrometeorology and Environmental Monitoring (Roshydromet) on assessment of the sea water and atmospheric air radioactive contamination in the Sea of Japan and in Kurile-Kamchatka region of the Pacific ocean, in connection with accident at the "Fukushima-1" NPP, two expedition surveys were conducted in the Sea of Japan and in the North-Western Pacific (in the area adjacent to Kurile Islands and in the Kuroshio current selected area (coordinates 36°00'-39°33' n., 146°33'-150°00' e.): first survey April - May 2011, second survey August-September 2012. Both surveys were conducted under the Russian Geographical Society patronage. The results of measurements of Cs-137, Cs-134, Sr-90, Pu-239,240 and H-3 concentrations in the sea water samples and I-131, Cs-137 and Cs-134 concentrations in atmospheric aerosol samples are presented and discussed. The data received allowed to conclude that the levels of contamination by products of accidental releases and discharges at "Fukushima-1" NPP observed in investigated water areas near the Russian Federation coast of the Sea of Japan and of the Kurile- Kamchatka region of the Pacific ocean have no hazard. However, these expedition surveys revealed large-scale contamination by Cs-137 and Cs-134 of water areas of the North-Western Pacific in the investigated region of the Kuroshio current. The Cs-137 concentration in sea water at a distance about 400 km from accidental NPP in April-May, 2011 reached 30 Bq/m3, which approximately 20 times exceed preaccidental level, and it was found that water mass till more than 100 m below the surface was contaminated. For correct estimation of current and potential consequences of the "Fukushima-1" accident for the Far-Eastern water areas a special study is reasonable to perform of transport with marine currents of products of accidental releases and discharges at "Fukushima-1" NPP.

  2. A multiproxy approach to constrain the source, composition and reactivity of sedimentary organic carbon in the eastern Yellow Sea (the northwestern Pacific)

    Science.gov (United States)

    Yoon, SukHee; Kim, JunHyun; Lee, DongHun; Yi, HiiIl; Yamamoto, Masanobu; Gal, JonKu; Choi, BoHyung; Kang, Sujin; Shin, KyungHoon

    2016-04-01

    We investigated the source, composition and reactivity of sedimentary organic carbon (OC) in a river-dominated continental marginal sea, the eastern Yellow Sea. A multi-proxy approach was applied to 9 riverbank sediments and 69 marine surface sediments, combining bulk and molecular organic parameters. The sedimentary OC in the marine surface sediments appears to have a predominantly marine origin (on average C/N ratio=7.0±0.6 and δ13CTOC=-21.9±0.5‰, n=69) with minor contribution of continental (i.e. soil- and lake/river-derived) OC (on average BIT index=0.00±0.01, n=69). However, the 14C values were depleted (on average -227±53‰, n=8), indicating that about 18-33% of ancient OC, potentially derived from erosion of sedimentary bedrocks or from fossil fuels such as petroleum might be added to the sedimentary OC pool. The possible contribution of petroleum-derived OC was confirmed by Carbon preference indices (CPI) of n-alkanes (<1). Accordingly, our results highlight an important contribution of ancient OC in the eastern Yellow Sea. Nonetheless, more work is needed to better constrain the source, composition, and age of the organic material supplied to the eastern Yellow Sea, given the lack of biogeochemical data from the Korean rivers.

  3. Source, composition and reactivity of sedimentary organic carbon in the river-dominated marginal seas: A study of the eastern Yellow Sea (the northwestern Pacific)

    Science.gov (United States)

    Yoon, Suk-Hee; Kim, Jung-Hyun; Yi, Hi-Il; Yamamoto, Masanobu; Gal, Jong-Ku; Kang, Sujin; Shin, Kyung-Hoon

    2016-08-01

    We investigated the source, composition and reactivity of sedimentary organic carbon (OC) in a river-dominated continental marginal sea, the eastern Yellow Sea. A multi-proxy approach was applied to 9 riverbank sediments and 69 marine surface sediments, combining bulk and molecular organic parameters. The riverbank sediments (n=9) have on average low C/N ratio (4.8±0.5) and enriched δ13CTOC values (-21.5±0.6%) while the BIT index is on average 0.27. The sedimentary OC in the marine surface sediments appears to have a predominantly marine origin (on average C/N ratio=7.0±0.6 and δ13CTOC=-21.9±0.5%, n=69) with minor contribution of continental (i.e. soil- and lake/river-derived) OC (on average BIT index=0.00±0.01, n=69). However, the Δ14C values were depleted (on average -227±53%, n=8). Accordingly, our results highlight that fossil OC, potentially derived from erosion of sedimentary bedrocks in the catchment areas and/or human activities is being contributed to the sedimentary OC pool in the eastern Yellow Sea. More work is needed to better constrain the source, composition, and age of the organic material supplied to the eastern Yellow Sea, given the lack of biogeochemical data from the Korean rivers.

  4. Participatory Modeling Processes to Build Community Knowledge Using Shared Model and Data Resources and in a Transboundary Pacific Northwest Watershed (Nooksack River Basin, Washington, USA)

    Science.gov (United States)

    Bandaragoda, C.; Dumas, M.

    2014-12-01

    As with many western US watersheds, the Nooksack River Basin faces strong pressures associated with climate variability and change, rapid population growth, and deep-rooted water law. This transboundary basin includes contributing areas in British Columbia, Canada, and has a long history of joint data collection, model development, and facilitated communication between governmental (federal, tribal, state, local), environmental, timber, agricultural, and recreational user groups. However, each entity in the watershed responds to unique data coordination, information sharing, and adaptive management regimes and thresholds, further increasing the complexity of watershed management. Over the past four years, participatory methods were used to compile and review scientific data and models, including fish habitat (endangered salmonid species), channel hydraulics, climate data, agricultural, municipal and industrial water use, and integrated watershed scale distributed hydrologic models from over 15 years of projects (from jointly funded to independent shared work by individual companies, agencies, and universities). A specific outcome of the work includes participatory design of a collective problem statement used for guidance on future investment of shared resources and development of a data-generation process where modeling results are communicated in a three-tiers for 1) public/decision-making, 2) technical, and 3) research audiences. We establish features for successful participation using tools that are iteratively developed, tested for usability through incremental knowledge building, and designed to provide rigor in modeling. A general outcome of the work is ongoing support by tribal, state, and local governments, as well as the agricultural community, to continue the generation of shared watershed data using models in a dynamic legal and regulatory setting, where two federally recognized tribes have requested federal court resolution of federal treaty rights

  5. Satellite-Based Surface Heat Budgets and Sea Surface Temperature Tendency in the Tropical Eastern Indian and Western Pacific Oceans for the 1997/98 El Nino and 1998/99 La Nina

    Science.gov (United States)

    Chou, Shu-Hsien; Chou, Ming-Dah; Chan, Pui-King; Lin, Po-Hsiung

    2002-01-01

    The 1997/98 is a strong El Nino warm event, while the 1998/99 is a moderate La Nina cold event. We have investigated surface heat budgets and sea surface temperature (SST) tendency for these two events in the tropical western Pacific and eastern Indian Oceans using satellite-retrieved surface radiative and turbulent fluxes. The radiative fluxes are taken from the Goddard Satellite-retrieved Surface Radiation Budget (GSSRB), derived from radiance measurements of the Japanese Geostationary Meteorological Satellite 5. The GSSRB covers the domain 40 deg S - 4 deg N, 90 deg E-17 deg W and a period from October 1997 to December 2000. The spatial resolution is 0.5 deg x 0.5 deg lat-long and the temporal resolution is 1 day. The turbulent fluxes are taken from Version 2 of the Goddard Satellite-based Surface Turbulent Fluxes (GSSTF-2). The GSSTF-2 has a spatial resolution of 1 deg x 1 deg lat-long over global Oceans and a temporal resolution of 1 day covering the period July 1987-December 2000. Daily turbulent fluxes are derived from the S S M (Special Sensor Microwave/Imager) surface wind and surface air humidity, and the SST and 2-m air temperature of the NCEP/NCAR reanalysis, using a stability-dependent bulk flux algorithm. The changes of surface heat budgets, SST and tendency, cloudiness, wind speed, and zonal wind stress of the 1997/98 El Nino relative to the1998/99 La Nina for the northern winter and spring seasons are analyzed. The relative changes of surface heat budgets and SST tendency of the two events are quite different between the tropical eastern Indian and western Pacific Oceans. For the tropical western Pacific, reduced solar heating (more clouds) is generally associated with decreased evaporative cooling (weaker winds), and vise versa. The changes in evaporative cooling over-compensate that of solar heating and dominate the spatial variability of the changes in net surface heating. Both solar heating and evaporative cooling offset each other to reduce

  6. The Employee as the Unknown Actor? A Discourse Analysis of the Employee Share Ownership Debate with Special Emphasis on Central and Eastern Europe

    Directory of Open Access Journals (Sweden)

    Kranz Olaf

    2016-05-01

    Full Text Available Background and purpose: Although employee share ownership (ESO deserves of a long tradition, we still know little about employees’ perspectives about ESO. The lack of knowledge about the employees’ attitudes towards ESO is discursively filled in the ESO debate. This paper challenges that deficit by carrying out a semantic analysis of the literature with the aim to identify the various actor constructions used implicitly in the ESO discourse.

  7. Physical and biogeochemical forcing of oxygen and nitrate changes during El Niño/El Viejo and La Niña/La Vieja upper-ocean phases in the tropical eastern South Pacific along 86° W

    Directory of Open Access Journals (Sweden)

    P. J. Llanillo

    2013-10-01

    Full Text Available Temporal changes in the water mass distribution and biogeochemical signals in the tropical eastern South Pacific are investigated with the help of an extended optimum multi-parameter (OMP analysis, a technique for inverse modeling of mixing and biogeochemical processes through a multidimensional least-square fit. Two ship occupations of a meridional section along 85°50' W from 14° S to 1° N are analysed during relatively warm (El Niño/El Viejo, March 1993 and cold (La Niña/La Vieja, February 2009 upper-ocean phases. The largest El Niño–Southern Oscillation (ENSO impact was found in the water properties and water mass distribution in the upper 200 m north of 10° S. ENSO promotes the vertical motion of the oxygen minimum zone (OMZ associated with the hypoxic equatorial subsurface water (ESSW. During a cold phase the core of the ESSW is found at shallower layers, replacing shallow (top 200 m subtropical surface water (STW. The heave of isopycnals due to ENSO partially explains the intrusion of oxygen-rich and nutrient-poor antarctic intermediate water (AAIW into the depth range of 150–500 m. The other cause of the AAIW increase at shallower depths is that this water mass flowed along shallower isopycnals in 2009. The shift in the vertical location of AAIW reaching the OMZ induces changes in the amount of oxygen advected and respired inside the OMZ: the larger the oxygen supply, the greater the respiration and the lower the nitrate loss through denitrification. Variations in the intensity of the zonal currents in the equatorial current system, which ventilates the OMZ from the west, are used to explain the patchy latitudinal changes of seawater properties observed along the repeated section. Significant changes reach down to 800 m, suggesting that decadal variability (Pacific decadal oscillation is also a potential driver in the observed variability.

  8. Getting Behind B Shares

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China Ocean Shipping(Group)Co.(COSCO) employs an experimental strategy of making acquisitions through the purchase of B shares COSCO Pacific Ltd.and its affili- ated companies held 4.5 million shares of China International Marine Containers(Grouo)Co.Ltd.(CIMC) as of March 6. Four months ago,the board of direc- tors of COSCO Container Industries Ltd. (COSCO Container)decided to buy more B shares of CIMC through the securities mar- ket.COSCO Container is a shell company registered in the British Virgin Islands with a

  9. Amphidromy links a newly documented fish community of continental Australian streams, to oceanic islands of the west Pacific.

    Directory of Open Access Journals (Sweden)

    Paul A Thuesen

    Full Text Available BACKGROUND: Indo-Pacific high island streams experience extreme hydrological variation, and are characterised by freshwater fish species with an amphidromous life history. Amphidromy is a likely adaptation for colonisation of island streams following stochastic events that lead to local extirpation. In the Wet Tropics of north-eastern Australia, steep coastal mountain streams share similar physical characteristics to island systems. These streams are poorly surveyed, but may provide suitable habitat for amphidromous species. However, due to their ephemeral nature, common non-diadromous freshwater species of continental Australia are unlikely to persist. Consequently, we hypothesise that coastal Wet Tropics streams are faunally more similar, to distant Pacific island communities, than to nearby faunas of large continental rivers. METHODS/PRINCIPAL FINDINGS: Surveys of coastal Wet Tropics streams recorded 26 species, 10 of which are first records for Australia, with three species undescribed. This fish community is unique in an Australian context in that it contains mostly amphidromous species, including sicydiine gobies of the genera Sicyopterus, Sicyopus, Smilosicyopus and Stiphodon. Species presence/absence data of coastal Wet Tropics streams were compared to both Wet Tropics river networks and Pacific island faunas. ANOSIM indicated the fish fauna of north-eastern Australian coastal streams were more similar to distant Pacific islands (R = 0.76, than to nearby continental rivers (R = 0.98. MAIN CONCLUSIONS/SIGNIFICANCE: Coastal Wet Tropics streams are faunally more similar to distant Pacific islands (79% of species shared, than to nearby continental fauna due to two factors. First, coastal Wet Tropics streams lack many non-diadromous freshwater fish which are common in nearby large rivers. Second, many amphidromous species found in coastal Wet Tropics streams and Indo-Pacific islands remain absent from large rivers of the Wet Tropics

  10. Present status in {sup 137}Cs contamination in the marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model simulation following the Fukushima accident - A state and problem in {sup 137}Cs contamination in the marine biota along the Pacific coast of eastern Japan derived from the dynamic biological model simulation after the Fukushima accident - A state and problem in {sup 137}Cs contamination in the marine biota along the Pacific coast of eastern Japan derived from the dynamic biological model simulation after the Fukushima accident

    Energy Technology Data Exchange (ETDEWEB)

    Tateda, Y.; Tsumune, D.; Tsubono, K.; Misumi, K. [Environmental Science Research Laboratory, CRIEPI, 1646, Abiko, Chiba, 270-1194 (Japan); Yamada, M. [Institute of radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Bunkyo, Hirosaki, Aomori, 036-8564 (Japan); Kanda, J.; Ishimaru, T. [Tokyo University of Marine Science and Technology, 4-5-7, Konan, Minato, Tokyo, 108-8477 (Japan)

    2014-07-01

    To understand the radioactive matter contamination of coastal biota in case of accidental release to the environment, the {sup 137}Cs levels in coastal biota around the Fukushima were reconstructed by dynamic model simulating non-equilibrated radioactive Cs transfer between seawater and organisms. Since, there is a disagreement between simulated radioactive Cs levels and observed concentrations in benthic organisms, being possibly attributable to the additional contamination source from sediment environment (Tateda et al. 2013), the {sup 137}Cs levels in organisms habituated not close to the sediment are calculated. Using the reconstructed {sup 137}Cs levels in seawater including atmospheric input and direct leakage after 1/March/2011 till 31/December/2012, {sup 137}Cs levels in sedentary organisms such as macro algae, bivalve and surface swimming plankton feeding fish e.g. as white bait were calculated along the Pacific Ocean coastal area of the Eastern Japan. The simulated temporal space distribution of the {sup 137}Cs levels in macro algae, algae feeding invertebrates, coastal bivalves, were generally agreed in the observed temporal profiles corresponding to the same food habitat organisms collected, while the magnitude of the {sup 137}Cs levels were several times lower than observed concentrations. Since the simulated reconstructed seawater levels are only verified by measured values after direct leakage, thus initial levels before the liquid release may be expected to be higher reconstructed level by simulation. The organisms are continuously exposed to initial contaminated seawater, reflecting actual seawater level increase in seawater, thus there may be possible deficit of initial source estimation in coastal surface water e.g. contribution from fine debris deposition to seaward from hydrogen explosion. In other word as shown in overall pushing up measured level compared to reconstructed level in organism, it also suggests the re-distributed {sup 137}Cs

  11. The potential of aerial photography for estimating surface areas of intertidal Pacific oyster beds (Crassostrea gigas)

    NARCIS (Netherlands)

    Kater, B.J.; Baars, J.M.D.D.

    2004-01-01

    Pacific oysters were introduced into the Eastern Scheldt in 1964 for breeding purposes. The first spatfall of wild Pacific oysters was recorded in 1976, and a second larval outburst in 1982 definitely settled wild Pacific oysters in the Eastern Scheldt waters. Oyster beds on intertidal and subtidal

  12. Physicochemical Characterization of Cloud Drop Residual Particles in Eastern Pacific Marine Stratocumulus: Airborne Measurements Downstream of a Newly-Developed Counterflow Virtual Impactor Inlet during the 2011 E-PEACE Campaign

    Science.gov (United States)

    Sorooshian, A.; Shingler, T.; Dey, S.; Brechtel, F. J.; Jonsson, H.; Metcalf, A. R.; Craven, J. S.; Coggon, M.; Lin, J. J.; Nenes, A.; Seinfeld, J.

    2011-12-01

    The aerosol nuclei that are the seeds of cloud drops are a critically important component of the atmosphere as they influence radiative transfer, visibility, and cloud microphysics. Aircraft must employ special inlets to exclusively sample cloud drops, which involves rejecting the smaller interstitial aerosol in clouds, and then subsequently drying the drops to leave only the residual particles. A new counterflow virtual impactor inlet (CVI) was recently deployed on the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE). Several state-of-the-art instruments sampling downstream of the CVI characterized the physical and chemical properties of the droplet residual particles including measurements of composition, size distribution, optical properties, and water-uptake properties. This work will summarize CVI measurements from over 25 flights during the E-PEACE campaign off the central coast of California between July and August. The flights specifically targeted aerosol-cloud interactions in a region where stratocumulus clouds are perturbed by emissions from ship traffic. New findings related to the physicochemical properties of drop residual particles will be highlighted in addition to a characterization of CVI performance.

  13. Prolonged El Niño conditions in 2014-2015 and the rapid intensification of Hurricane Patricia in the eastern Pacific: EL NIÑO AND HURRICANE PATRICIA

    Energy Technology Data Exchange (ETDEWEB)

    Foltz, Gregory R. [NOAA/Atlantic Oceanographic and Meteorological Laboratory, Miami Florida USA; Balaguru, Karthik [Marine Sciences Laboratory, Pacific Northwest National Laboratory, Seattle Washington USA

    2016-10-07

    Hurricane Patricia was the most intense tropical cyclone on record in the eastern North Pacific or Atlantic, reaching a peak intensity of 95 m s-1 only 30 hours after attaining hurricane status (33 m s-1). Here it is shown that exceptionally warm sea surface temperatures (SSTs), a deeper than normal thermocline, and strong near-surface salinity stratification all aided Patricia’s rapid intensifciation, combining to increase its Dynamic Potential Intensity by 10–21 m s-1. Anomalous surface warming and thermocline deepening along Patricia’s track were driven by prolonged El Niño during 2014–15 and punctuated by the buildup to the extreme El Niño of 2015–16. In the region where Patricia intensified, SST was 1.5°C higher and sea surface height was 10 cm higher compared to conditions during the last extreme El Niño in 1997, emphasizing the extraordinary nature of the 2015 anomalies.

  14. Expedition surveys of the sea water and atmospheric air radioactive contamination in the Russian Far Eastern coastal areas and in the North- Western Pacific in connection with accident at the 'Fukushima-1' NPP

    Energy Technology Data Exchange (ETDEWEB)

    Nikitin, Aleksandr; Shershakov, Viacheslav; Artemev, Georgii [Research and Production Association ' Typhoon' (RPA ' Typhoon' ), Obninsk, Kaluga Region (Russian Federation); Ramzaev, Valery [Ramzaev Saint-Petersburg Research Institute of Radiation Hygiene, Saint-Petersburg (Russian Federation); Osokin, Vladimir [V.G.Khlopin Radium institute, Saint-Petersburg (Russian Federation); Sevastianov, Aleksandr [Far Eastern Regional Hydrometeorological Research Institute, Vladivostok (Russian Federation)

    2014-07-01

    In accordance with decision of the Russian Federation Federal Service on Hydro-meteorology and Environmental Monitoring (Roshydromet) on assessment of the sea water and atmospheric air radioactive contamination in the Russian coastal areas of the Far East in connection with accident at the 'Fukushima-1' NPP in Japan, two radioecological expedition surveys were conducted onboard of research vessels of the Far Eastern Regional Hydro-meteorological Research Institute (FERHRI) of Roshydromet in the Sea of Japan and in the North-Western Pacific (in the area adjacent to Kurile Islands and in the Kuroshio current selected area (coordinates 36 deg. 00'- 39 deg. 33' n., 146 deg. 33'- 150 deg. 00' e.): first survey in April-May 2011, onboard R/V 'Pavel Gordienko', second survey in August-September 2012, onboard R/V 'Akademik Shokalsky'. Both surveys were conducted under the Russian Geographical Society patronage. The leading Russian institutions dealing with ensuring of population radiation safety and protection of environment from radioactive contamination were enlisted to investigations. The following main observations were performed during the surveys: constant measurement of gamma-radiation dose rate above the sea surface; twenty-four hour sampling of atmospheric aerosols, sea water sampling from the surface and deep water horizons with preliminary concentrating of radionuclides for onboard gamma-spectrometry and for subsequent transportation to the shore laboratories for further analysis. During the expeditions, a real-time data were received onboard of research vessels which characterize impact of input of radioactive products of the 'Fukushima-1' NPP accident on radioactive contamination of environment existed on that period (these are onboard estimates of {sup 137}Cs and {sup 134}Cs concentrations in the sea water samples and {sup 131}I, {sup 137}Cs, {sup 134}Cs content in atmospheric aerosol samples, data

  15. Application of multiplex PCR approaches for shark molecular identification: feasibility and applications for fisheries management and conservation in the Eastern Tropical Pacific.

    Science.gov (United States)

    Caballero, S; Cardeñosa, D; Soler, G; Hyde, J

    2012-03-01

    Here we describe the application of new and existing multiplex PCR methodologies for shark species molecular identification. Four multiplex systems (group ID, thresher sharks, hammerhead sharks and miscellaneous shark) were employed with primers previously described and some designed in this study, which allow for species identification after running PCR products through an agarose gel. This system was implemented for samples (bodies and fins) collected from unidentified sharks landed in the port of Buenaventura and from confiscated tissues obtained from illegal fishing around the Malpelo Island Marine Protected Area, Pacific Coast of Colombia. This method has allowed reliable identification, to date, of 407 samples to the genus and/or species levels, most of them (380) identified as the pelagic thresher shark (Alopias pelagicus). Another seven samples were identified as scalloped hammerhead sharks (Sphyrna lewini). This is an easy-to-implement and reliable identification method that could even be used locally to monitor shark captures in the main fishing ports of developed and developing countries.

  16. Where have all the carbonates gone? A model comparison of calcium carbonate budgets before and after the 1982 1983 El Nino at Uva Island in the eastern Pacific

    Science.gov (United States)

    Eakin, C. M.

    1996-06-01

    El Nifio related coral mortality and a subsequent increase in crustose coralline algae and sea urchins have resulted in profound changes to the coral reef ecosystem at Uva Island, Panama (Pacific coast). New data and a model are presented that analyze the CaCO3 budget of the reef. The model accounts for production by corals and coralline algae, erosion by Diadema, infauna, fish and other motile organisms, and the retention of sediments as a function of size. The 2.5 ha reef is currently eroding at an average rate of 4,800 kg/y or -0.19 kg/m2/y but there is tremendous variation among reef zones. While deposition in other zones range from +0.1 to 0.4 kg/m2/y, erosion of the seaward reef base averages about -3.65 kg/m2/y. The damselfish/algal lawn symbiosis protects portions of the reef framework, reducing net losses there by 2,000 kg/y (up to 0.33 kg/m2/y). Before the 1982-1983 El Niño, the overall reef was depositional. At that time, estimated production exceeded erosion in most zones, resulting in a net deposition of approximately 8,600 kg/y or 0.34 kg/m2/y.

  17. Eastern tropical Pacific vegetation response to rapid climate change and sea level rise: A new pollen record from the Gulf of Tehuantepec, southern Mexico

    Science.gov (United States)

    Hendy, I. L.; Minckley, T. A.; Whitlock, C.

    2016-08-01

    A 30,000-year-long pollen record from the Gulf of Tehuantepec, southern Mexico shows the varying influence of air temperature, precipitation and eustatic sea-level rise on changes in coastal and upland vegetation patterns. During the late-glacial period, pine-juniper forests grew in the Sierra Madre del Sur along the Pacific Slope with broadleaf forests present at low elevations. Coastal wetland and riparian vegetation were limited in distribution. Significant cooling associated with Heinrich 1 (17,000-15,000 cal yr BP) resulted in an expansion of pine-juniper woodland. By the time of Bølling-Allerød warming (14,700-13,000 cal yr BP), extensive mangrove forest development was assisted by sea-level rise and reduced precipitation associated with a more southerly position of the Intertropical Convergence Zone (ITCZ) than at present. Concurrently, the expansion of oak into pine woodlands was promoted by warmer conditions than before. Increased summer precipitation in the early Holocene and stabilizing sea levels limited mangrove forests along the coast and allowed mixed conifer and hardwood forest to become more widespread inland. The onset of a more seasonal climate, driven by a weakening of the Mexican monsoon and a southerly shift in ITCZ position led to the establishment of modern open forests of pine and oak after 4300 cal yr BP.

  18. FastStats: Health of Asian or Pacific Islander Population

    Science.gov (United States)

    ... NCHS Home Health of Asian or Pacific Islander Population Recommend on Facebook Tweet Share Compartir Data are ... U.S. Live births for Asian or Pacific Islander population Number of births: 281,264 Births per 1, ...

  19. Particle mixing rates in sediments of the eastern equatorial Pacific: Evidence from 210Pb, 239,240Pu and 137Cs distributions at MANOP sites

    Science.gov (United States)

    Cochran, J. Kirk

    1985-05-01

    Particle mixing rates ( DB) calculated from excess 210Pb gradients in sediments of the east equatorial Pacific range from 0.04 to 0.5 cm 2/y, with variation of a factor of 3-4 at a single site. Diffusion of the 236Ra daughter 222Rn may affect 210Pb distributions under conditions of slow mixing and low 210Pb flux to the seafloor, as shown by a siliceous ooze-clay core which contained the fallout radionuclides 239,240Pu and 137Cs but no excess 210Pb (relative to 226Ra). There is no clear relationship between 210Pbderived mixing rates and sediment type, accumulation rate or organic carbon flux to the sediments. Comparison of 210Pb mixing rates with those calculated from 239,240Pu and 137Cs distributions reveals better agreement for a pulse input of the fallout radionuclides ( DB = 0.03-0.4 cm2/ y) than for continuous input at a constant rate ( DB = 0.1-1.6 cm2/ y), although the Pu and 137Cs data are better fit by the latter model. The agreement may be fortuitous because 239,240Pu and 137Cs appear significantly deeper than 210Pb in at least one core. Tracer separation could be caused by particle size-selective mixing by the benthic fauna or by chemical mobilization. If the fallout radionuclides are scavenged from surface waters by large, organic-rich particles such as fecal pellets, their release and migration may result from decomposition of the carrier in surface sediments. Either a relatively unreactive form of Pu (e.g. oxidized Pu) has been released by this process or a one-dimensional model is inadequate to explain its observed penetration into the sediments. Activity ratios of 239,240Pu /137Cs in the sediments decrease with increasing north latitude, and the trend reflects higher fluxes of 239,240Pu near the weapons test site at Christmas Island (2°N). The 239,240Pu /137Cs ratios and fluxes to the sediment (assuming constant input) at the siliceous ooze-red clay site are consistent with published sediment trap data from a nearby site. Thus if fallout

  20. Western juniper in eastern Oregon.

    Science.gov (United States)

    Donald R. Gedney; David L. Azuma; Charles L. Bolsinger; Neil. McKay

    1999-01-01

    This report analyzes and summarizes a 1988 inventory of western juniper (Juniperus occidentalis Hook.) in eastern Oregon. This inventory, conducted by the Pacific Northwest Research Station of the USDA Forest Service, was intensified to meet increased need for more information about the juniper resource than was available in previous inventories. A...

  1. From the lavas to the gabbros: 1.25 km of geochemical characterization of upper oceanic crust at ODP/IODP Site 1256, eastern equatorial Pacific

    Science.gov (United States)

    Höfig, Tobias W.; Geldmacher, Jörg; Hoernle, Kaj; Hauff, Folkmar; Duggen, Svend; Garbe-Schönberg, Dieter

    2014-12-01

    Here we present trace element and Sr-Nd-Hf-Pb (double spike) isotopic data covering the entire igneous section of oceanic crust drilled at Ocean Drilling Program (ODP)/Integrated Ocean Drilling Program (IODP) Site 1256 on the Cocos Plate. The penetrated interval extends from the upper lavas through the sheeted dike complex to the gabbroic plutonic rocks, formed during superfast spreading at the mid-Miocene equatorial East Pacific Rise. The data are used to characterize the effects of chemical alteration, resulting from convection of seawater and hydrothermal fluids, on the trace element and isotopic composition of oceanic crust. Compared to normal mid-ocean-ridge basalt, the igneous basement of Site 1256 (Holes 1256C/D) is isotopically slightly enriched but shows only narrow downhole variations in Nd-Hf-Pb isotope ratios: 143Nd/144Nd = 0.513089 ± 0.000028 (2σ), 176Hf/177Hf = 0.283194 ± 0.000033 (2σ), 206Pb/204Pb = 18.61 ± 0.11 (2σ), 207Pb/204Pb = 15.521 ± 0.014 (2σ), 208Pb/204Pb = 38.24 ± 0.15 (2σ). We believe that this minor variability is mainly of primary (magmatic) origin. The Sr isotopic composition shows considerably larger variation and, as expected, serves as sensitive tracer of seawater influence, which is particularly pronounced in the lava-dike transition zone and the sheeted dikes. The seawater influence is most prominent in a highly metal sulfide-enriched breccia layer encountered in the transition zone with 87Sr/86Sr of ~ 0.706, indicating a maximum water-rock mixing ratio of ~ 12. However, compared to the igneous section drilled at Site 504 (Hole 504B), which formed at intermediate, i.e., slower spreading rates at the Galápagos Spreading Center and hosting a much thicker sulfide-rich stockwork zone, the average intensity of water-rock interaction is lower. This is expressed by lesser mobility of base metals, narrower variability of alteration-sensitive incompatible elements, and less radiogenic Sr isotopic compositions on average at Site

  2. Meeting report: threats to human health and environmental sustainability in the pacific basin.

    Science.gov (United States)

    Arnold, Robert G; Carpenter, David O; Kirk, Donald; Koh, David; Armour, Margaret-Ann; Cebrian, Mariano; Cifuentes, Luis; Khwaja, Mahmood; Ling, Bo; Makalinao, Irma; Paz-Y-Miño, César; Peralta, Genandrialine; Prasad, Rajendra; Singh, Kirpal; Sly, Peter; Tohyama, Chiharu; Woodward, Alistair; Zheng, Baoshan; Maiden, Todd

    2007-12-01

    The coastal zone of the Pacific Rim is home for about one-third of the world's population. Disproportionate growth of Far Eastern economies has produced a disproportionate share of related environmental difficulties. As the region searches for acceptable compromises between growth and environmental quality, its influence on global environmental health is certain to increase. Consequences of global environmental change such as habitat alteration, storms, and sea level rise will be particularly acute among Pacific Rim nations. Adverse health effects from arsenic exposure in Pacific Rim nations have been used to justify drinking water standards in the United States and elsewhere. As global manufacturing in the Pacific Rim increases, the centroid of global air quality and waste management issues will shift further toward Far Eastern nations. The Eleventh International Conference of the Pacific Basin Consortium (PBC) was held in September 2005 in Honolulu, Hawaii. The purpose of the conference was to bring together individuals to discuss regional challenges to sustainable growth. The historic emphasis of the conference on hazardous wastes in relation to human health makes the PBC an ideal forum for discussing technical aspects of sustainable economic growth in the Pacific region. That role is reflected in the 2005 PBC conference themes, which included management of arsenic in potable waters, air quality, climate change, pesticides, mercury, and electronics industry waste-each with emphasis on relationships to human health. Arsenic management exemplifies the manner in which the PBC can focus interdisciplinary discussion in a single technical area. The conference program provided talks on arsenic toxicology, treatment technologies, management of arsenic-bearing residuals from water treatment, and the probable societal costs and benefits of arsenic management.

  3. Shared lives, shared energy

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, P.; Goss, K.

    1982-07-01

    A social experiment in Denmark is described in which 25 families combine private ownership (each family owns its own home) and collectivism (each family owns 1/25 of the grounds, large common house and other facilities). The superinsulated individual homes are small (< 1000 ft/sup 2/) but the common house (7800 ft/sup 2/) provides dining and meeting facilities for all 25 families as well as a central heating plant. Heat may be supplied from solar, wind and/or oil-fired boiler. Adequate hot water storage is provided using solar collectors and a 55 kW Vesta wind generator (surplus power is sold). All south facing roof surfaces are fitted with solar collectors (4455 ft/sup 2/ total). A total of 70% of the energy used is produced on site (solar and wind). The manner of living and sharing (child care, automobiles, cooking, etc.) is described as well as typical floor plans for the units. Other collective housing in Denmark is described and it is postulated that overdrevet may serve as a model. (MJJ)

  4. First record and redescription of Tisbella pulchella (Copepoda: Harpacticoida from the eastern tropical Pacific Primer registro y redescripción de Tisbella pulchella (Copepoda: Harpacticoida del Pacífico tropical este

    Directory of Open Access Journals (Sweden)

    Francisco Neptalí Morales-Serna

    2008-06-01

    Full Text Available Specimens of the genus Tisbella Gurney, 1927 were found during a series of sampling campaigns in 2 brackish systems in southern Sinaloa (north-western Mexico. The specimens were identified as Tisbella pulchella (Wilson, 1932, a species of harpacticoid copepod originally described from material collected from the Woods Hole region (USA and found also in the Bermuda Islands. A thorough comparison between the material collected in Mexican coastal systems in the eastern tropical Pacific and previous redescriptions of the type material is presented. It is shown that the only differences between the most accurate and detailed redescription available and the present description is in the number of setae of the arthrite and palp of the maxillule, and in the number of accessory setae of the maxilliped. Some notes on the biogeography of the species are presented and it is concluded that T. pulchella is the most widely distributed species within the genus.Se encontraron ejemplares del género Tisbella Gurney, 1927 durante una serie de muestreos de meiofauna en 2 sistemas costeros del sur de Sinaloa (noroeste de México. Los organismos fueron identificados como Tisbella pulchella (Wilson, 1932, una especie de copépodo harpacticoide originalmente descrita a partir de material recolectado en la región de Woods Hole (EUA y también registrada en las islas Bermuda. Se presenta una comparación de los especímenes recolectados en sistemas costeros mexicanos del Pacífico tropical este y las redescripciones disponibles del material tipo. Se observó que las únicas diferencias observadas entre la redescripción más detallada de la especie y la presente descripción es el número de setas del artrito y palpo de la maxíllula y el número de setas accesorias del maxilípedo. Finalmente se dan algunas notas acerca de su biogeografía y se concluye que T. pulchella es la especie con la distribución más amplia del género.

  5. Sharing Economy

    DEFF Research Database (Denmark)

    Marton, Attila; Constantiou, Ioanna; Thoma, Antonela

    De spite the hype the notion of the sharing economy is surrounded by, our understanding of sharing is surprisingly undertheorized. In this paper, we make a first step towards rem edying this state of affairs by analy sing sharing as a s ocial practice. Based on a multi ple - case study, we analyse...... the institutional assemblage of sharing on online platforms to counter the prevalent assumpti o n i n the literature that sharing derives primarily from the shareability of goods and resources. Sharing, we contend, is a fundament al human practice that, in our case study, takes the particular form of coord inated...

  6. Eastern Pacific Emitted Aerosol Cloud Experiment

    OpenAIRE

    Russell, Lynn M.; Sorooshian, Armin; Seinfeld, John H.; Albrecht, Bruce A.; Nenes, Athanasios; Ahlm, Lars; Chen, Yi-Chun; Coggon, Matthew; Craven, Jill S.; Flagan, Richard C.; Frossard, Amanda A.; Jonsson, Haflidi; Jung, Eunsil; Lin, Jack J.; Metcalf, Andrew R.

    2013-01-01

    Aerosol–cloud–radiation interactions are widely held to be the largest single source of uncertainty in climate model projections of future radiative forcing due to increasing anthropogenic emissions. The underlying causes of this uncertainty among modeled predictions of climate are the gaps in our fundamental understanding of cloud processes. There has been significant progress with both observations and models in addressing these important questions but quantifying them correctly is nontrivi...

  7. Sharing Economy

    DEFF Research Database (Denmark)

    Marton, Attila; Constantiou, Ioanna; Thoma, Antonela

    De spite the hype the notion of the sharing economy is surrounded by, our understanding of sharing is surprisingly undertheorized. In this paper, we make a first step towards rem edying this state of affairs by analy sing sharing as a s ocial practice. Based on a multi ple - case study, we analyse...

  8. Zonal displacement of western Pacific warm pool and zonal wind anomaly over the Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The thermal condition anomaly of the western Pacific warm pool and its zonal displacement have very important influences on climate change in East Asia and even the whole world.However, the impact of the zonal wind anomaly over the Pacific Ocean on zonal displacement of the warm pool has not yet been analyzed based on long-term record. Therefore, it is important to study the zonal displacement of the warm pool and its response to the zonal wind anomaly over the equatorial Pacific Ocean. Based on the NCDC monthly averaged SST (sea surface temperature) data in 2°×2° grid in the Pacific Ocean from 1950 to 2000, and the NCEP/NCAR global monthly averaged 850 hPa zonal wind data from 1949 to 2000, the relationships between zonal displacements of the western Pacific warm pool and zonal wind anomalies over the tropical Pacific Ocean are analyzed in this paper. The results show that the zonal displacements are closely related to the zonal wind anomalies over the western, central and eastern equatorial Pacific Ocean. Composite analysis indicates that during ENSO events, the warm pool displacement was trigged by the zonal wind anomalies over the western equatorial Pacific Ocean in early stage and the process proceeded under the zonal wind anomalies over the central and eastern equatorial Pacific Ocean unless the wind direction changes. Therefore, in addition to the zonal wind anomaly over the western Pacific, the zonal wind anomalies over the central and eastern Pacific Ocean should be considered also in investigation the dynamical mechanisms of the zonal displacement of the warm pool.

  9. Pacific Standard

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The United States pushes for greater economic integration of the Asia-Pacific region Barack Obama has been an active free trade promoter in recent months. The U.S. president signed free trade agreements with South Korea,

  10. Sharing City

    DEFF Research Database (Denmark)

    This magazine offers an insight into the growing commercial innovation, civic movements, and political narratives surrounding sharing economy services, solutions and organisational types. It presents a cross-section of the manifold sharing economy services and solutions that can be found in Denmark....... Solutions of sharing that seeks to improve our cities and local communities in both urban and rural environments. 24 sharing economy organisations and businesses addressing urban and rural issues are being portrayed and seven Danish municipalities that have explored the potentials of sharing economy....... Moreover, 15 thought leading experts - professionals and academic - have been invited to give their perspective on sharing economy for cities. This magazine touches upon aspects of the sharing economy as mobility, communities, sustainability, business development, mobility, and urban-rural relation....

  11. Response of the tropical Pacific Ocean to El Niño versus global warming

    Science.gov (United States)

    Liu, Fukai; Luo, Yiyong; Lu, Jian; Wan, Xiuquan

    2017-02-01

    Climate models project an El Niño-like SST response in the tropical Pacific Ocean to global warming (GW). By employing the Community Earth System Model and applying an overriding technique to its ocean component, Parallel Ocean Program version 2, this study investigates the similarity and difference of formation mechanism for the changes in the tropical Pacific Ocean under El Niño and GW. Results show that, despite sharing some similarities between the two scenarios, there are many significant distinctions between GW and El Niño: (1) the phase locking of the seasonal cycle reduction is more notable under GW compared with El Niño, implying more extreme El Niño events in the future; (2) in contrast to the penetration of the equatorial subsurface temperature anomaly that appears to propagate in the form of an oceanic equatorial upwelling Kelvin wave during El Niño, the GW-induced subsurface temperature anomaly manifest in the form of off-equatorial upwelling Rossby waves; (3) while significant across-equator northward heat transport (NHT) is induced by the wind stress anomalies associated with El Niño, little NHT is found at the equator due to a symmetric change in the shallow meridional overturning circulation that appears to be weakened in both North and South Pacific under GW; and (4) heat budget analysis shows that the maintaining mechanisms for the eastern equatorial Pacific warming are also substantially different.

  12. Response of the tropical Pacific Ocean to El Niño versus global warming

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fukai; Luo, Yiyong; Lu, Jian; Wan, Xiuquan

    2016-04-15

    Climate models project an El Niño-like SST response in the tropical Pacific Ocean to global warming (GW). By employing the Community Earth System Model (CESM) and applying an overriding technique to its ocean component, Parallel Ocean Program version 2 (POP2), this study investigates the similarity and difference of formation mechanism for the changes in the tropical Pacific Ocean under El Niño and GW. Results show that, despite sharing some similarities between the two scenarios, there are many significant distinctions between GW and El Niño: 1) the phase locking of the seasonal cycle reduction is more notable under GW compared with El Niño, implying more extreme El Niño events in the future; 2) in contrast to the penetration of the equatorial subsurface temperature anomaly that appears to propagate in the form of an oceanic equatorial upwelling Kelvin wave during El Niño, the GW-induced subsurface temperature anomaly manifest in the form of off-equatorial upwelling Rossby waves; 3) while significant across-equator northward heat transport (NHT) is induced by the wind stress anomalies associated with El Niño, little NHT is found at the equator due to a symmetric change in the shallow meridional overturning circulation that appears to be weakened in both North and South Pacific under GW; and 4) the maintaining mechanisms for the eastern equatorial Pacific warming are also substantially different.

  13. Structural Transformations of the Economy in the Pacific Region of Russia and Efficiency Trends

    Directory of Open Access Journals (Sweden)

    Peter Yakovlevich Baklanov

    2016-03-01

    Full Text Available Pacific Russia is considered as an aqua-territorial macro-region entering the Far Eastern Federal Okrug and its adjacent water area within a 200-mile sea economic zone. The macro-region has the richest nature-resource potential of a dry land and the sea, the possibilities to use the sea transport for communications of Russia and Europe with the countries of the Asian-Pacific region. In Pacific Russia, two latitudinal zones are allocated: the northern and southern ones, consisting of the territories of the Far Eastern Federal Okrug of Russia. Combinations of activities by the subjects and by the latitudinal zones are considered as the territorial structures of economy. The distinctions of these latitudinal zones by their socio-economic potential and the level of development are shown. By the changes of homogeneous activities in the subjects and their ratios, measured in the shares of the added cost, the assessment of the structural transformation of economy was carried out in the latitudinal zones from 2004 to 2013. The tendencies of the transformation of the territorial structures of economy were revealed in the latitudinal zones. The greatest changes of the structures of economy occurred in the northern zone for this period. In the southern zone, the structural transformations of economy were a little less, except for Sakhalin. In this case, in both latitudinal zones, a share of processing manufactures reduced and that of the extracting industries increased. The generalized assessment of the changes in social and economic efficiency (by increased personal income, labor productivity, profits in correlation with the structural changes in the economy of the regions of Pacific Russia has been made. The authors note that an important premise for building a sufficiently sustainable system of interregional division of labor in Pacific Russia is the location of extractive industries and initial stages of the manufacturing industry activities in the

  14. Observations of carbon dioxide in the surface waters of the Eastern North Pacific Ocean and the Bering Sea from 21 July 1968 to 03 September 1968 (NODC Accession 7100114)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Measurements of the equilibrium concentration of carbon dioxide in the air and surface waters of the North Pacific Ocean and the Bering Sea are presented....

  15. Sharing code

    OpenAIRE

    Kubilius, Jonas

    2014-01-01

    Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing.

  16. Two-types of Early Cretaceous adakitic porphyries from the Luxi terrane, eastern North China Block: Melting of subducted Paleo-Pacific slab and delaminated newly underplated lower crust

    Science.gov (United States)

    Wang, Hao; Xu, Zhaowen; Lu, Xiancai; Fu, Bin; Lu, Jianjun; Yang, Xiaonan; Zhao, Zengxia

    2016-01-01

    The origin and tectonic setting of Early Cretaceous adakitic rocks from the Luxi terrane in the eastern North China Block (NCB) remain debated. To resolve this issue, we determined whole-rock geochemistry, zircon U-Pb ages, and in situ Hf-O isotopes of the Mengyin and Liujing adakitic porphyries from the Luxi terrane. Zircon U-Pb dating results reveal that both the Mengyin and Liujing plutons were emplaced during the Early Cretaceous, with weighted mean 206Pb/238U ages of 130 ± 1 Ma (2σ) and 131 ± 2 Ma (2σ), respectively. In addition, abundant Neoarchean-Paleoproterozoic inherited zircon cores are identified in the Mengyin adakitic porphyry with 207Pb/206Pb ages ranging from 2.53 to 2.42 Ga. Rocks of both plutons are silicic (SiO2 = 65.4-70.2 wt.%), metaluminous, and alkaline in composition, comprising mainly quartz syenite porphyries. Samples from both plutons are enriched in large ion lithophile elements (LILEs) (e.g., Rb, Sr, and Ba), and light rare earth elements (LREEs), depleted in high field strength elements (HFSEs) (e.g., Nb, Ta, and Ti), and heavy rare earth elements (HREEs), and have either positive or no Eu anomalies. In addition, both adakitic porphyries have high Mg# values (51-64), high Sr and La contents, low Y and Yb contents, and high Sr/Y (Mengyin = 149-264; Liujing = 58-110) and (La/Yb)N (Mengyin = 32.4-45.3; Liujing = 43.8-53.1) ratios, similar to adakitic rocks worldwide. The Mengyin adakitic porphyry has higher whole-rock εNd(t) values (-5.8 to - 4.1), more radiogenic Pb [(206Pb/204Pb)i = 18.35-18.39, (207Pb/204Pb)i = 15.55-15.56, (208Pb/204Pb)i = 38.20-38.23], higher zircon rim εHf(t) values (+ 3.3 to + 8.8) and δ18O values (+ 6.5‰ to + 7.9‰), and lower (87Sr/86Sr)i ratios (0.7049-0.7050) than the Liujing adakitic porphyry [εNd(t) = - 12.4 to - 12.2, (206Pb/204Pb)i = 17.63-17.72, (207Pb/204Pb)i = 15.56-15.58, (208Pb/204Pb)i = 37.76-37.94, εHf(t) = - 14.8 to - 11.2, δ18O = + 5.9‰ to + 7.1‰, (87Sr/86Sr)i = 0.7090-0.7091]. The

  17. Discrepancia taxonómica y riqueza de corales zooxantelados del Pacífico oriental durante el Cenozoico Taxonomic distinctness and richness of eastern Pacific zooxanthellate corals during the Cenozoic

    Directory of Open Access Journals (Sweden)

    Héctor Reyes-Bonilla

    2012-12-01

    Full Text Available La fauna de corales zooxantelados del Pacífico oriental ha sufrido cambios ocasionados por extinciones, especiación e inmigración desde varias provincias zoogeográficas. Aquí se analizan los cambios en la riqueza y en la discrepancia taxonómica y su varianza (Δ+ y Λ+, indicadores de la biodiversidad que cuantifican la longitud del árbol taxonómico, para los corales del oeste de las Américas durante el Cenozoico, a partir de un análisis de la presencia temporal de 148 especies, en intervalos de un millón de años. La discrepancia taxonómica fue muy estable durante el Cenozoico (alrededor de 44-50 unidades, mientras que la riqueza fluctuó de 42 especies en el Eoceno, hasta 3 en el Mioceno; esto indica que Δ+ no se afectó con las oscilaciones en el número de especies. Por otro lado, la riqueza y la varianza de la discrepancia taxonómica se comportan de manera inversa, dado que en intervalos temporales con alto número de especies, éstas pertenecieron a grupos taxonómicamente afines. Finalmente, la comparación de Δ+ y Λ+ indicó que los índices se asocian negativamente. Así, es posible que la redundancia ecológica sea alta y menor la tolerancia a cambios ambientales cuando es mayor la discrepancia taxonómica, dado que las especies están arregladas en un reducido número de géneros o familias.The zooxanthellate coral fauna of the eastern Pacific has changed due to mass extinctions, speciation and immigration from several zoogeographic provinces. In this study we analyze changes in richness and taxonomic distinctness and variance (Δ+ y Λ+, biodiversity indicators that quantify the length of the taxonomic tree of the species for stony corals of western America during the Cenozoic, on the basis of an analysis of the temporal occurrence of 148 species, arranged in one-million year intervals. Taxonomic distinctness was very stable during the Cenozoic (around 44-50 units, while species richness fluctuated from 42 species in

  18. File sharing

    NARCIS (Netherlands)

    van Eijk, N.

    2011-01-01

    ‘File sharing’ has become generally accepted on the Internet. Users share files for downloading music, films, games, software etc. In this note, we have a closer look at the definition of file sharing, the legal and policy-based context as well as enforcement issues. The economic and cultural impact

  19. Discover the Hidden Jewels in Your Library and Sharing the Wealth through Collaboration. Selected Papers from PIALA 2011, Pacific Islands Association of Libraries, Archives, and Museums Annual Conference (21st, Kosrae, Federated States of Micronesia, November 14-17, 2011)

    Science.gov (United States)

    Drake, Paul B., Ed.

    2012-01-01

    This publication follows the tradition of publishing selected papers from Pacific Islands Association of Libraries, Archives and Museums (PIALA) annual conferences. This 21st annual conference was held in Kosrae, Federated States of Micronesia, November 14-17, 2011. The volume begins with a listing of the members of the PIALA 2011 Planning…

  20. Shared leadership

    DEFF Research Database (Denmark)

    Ulhøi, John Parm; Müller, Sabine

    2012-01-01

    The aim of this paper is twofold. First, this paper comprehensively will review the conceptual and empirical literature to identify such critical underlying mechanisms which enable shared or collective leadership. Second, this article identifies the antecedents and outcomes of shared leadership...... according to the literature review to develop a re-conceptualised and synthesized framework for managing the organizational issues associated with shared leadership on various organizational levels. The paper rectifies this by identifying the critical factors and mechanisms which enable shared leadership...... and its antecedents and outcomes, and to develop a re-conceptualized and synthesized framework of shared leadership. The paper closes with a brief discussion of avenues for future research and implications for managers....

  1. Sharing Graphs

    CERN Document Server

    Sahasranand, K R

    2010-01-01

    Almost all known secret sharing schemes work on numbers. Such methods will have difficulty in sharing graphs since the number of graphs increases exponentially with the number of nodes. We propose a secret sharing scheme for graphs where we use graph intersection for reconstructing the secret which is hidden as a sub graph in the shares. Our method does not rely on heavy computational operations such as modular arithmetic or polynomial interpolation but makes use of very basic operations like assignment and checking for equality, and graph intersection can also be performed visually. In certain cases, the secret could be reconstructed using just pencil and paper by authorised parties but cannot be broken by an adversary even with unbounded computational power. The method achieves perfect secrecy for (2, n) scheme and requires far fewer operations compared to Shamir's algorithm. The proposed method could be used to share objects such as matrices, sets, plain text and even a heterogeneous collection of these. S...

  2. Shared leadership

    DEFF Research Database (Denmark)

    Ulhøi, John Parm; Müller, Sabine

    2012-01-01

    The aim of this paper is twofold. First, this paper comprehensively will review the conceptual and empirical literature to identify such critical underlying mechanisms which enable shared or collective leadership. Second, this article identifies the antecedents and outcomes of shared leadership...... according to the literature review to develop a re-conceptualised and synthesized framework for managing the organizational issues associated with shared leadership on various organizational levels. The paper rectifies this by identifying the critical factors and mechanisms which enable shared leadership...... and its antecedents and outcomes, and to develop a re-conceptualized and synthesized framework of shared leadership. The paper closes with a brief discussion of avenues for future research and implications for managers....

  3. Shared Attention.

    Science.gov (United States)

    Shteynberg, Garriy

    2015-09-01

    Shared attention is extremely common. In stadiums, public squares, and private living rooms, people attend to the world with others. Humans do so across all sensory modalities-sharing the sights, sounds, tastes, smells, and textures of everyday life with one another. The potential for attending with others has grown considerably with the emergence of mass media technologies, which allow for the sharing of attention in the absence of physical co-presence. In the last several years, studies have begun to outline the conditions under which attending together is consequential for human memory, motivation, judgment, emotion, and behavior. Here, I advance a psychological theory of shared attention, defining its properties as a mental state and outlining its cognitive, affective, and behavioral consequences. I review empirical findings that are uniquely predicted by shared-attention theory and discuss the possibility of integrating shared-attention, social-facilitation, and social-loafing perspectives. Finally, I reflect on what shared-attention theory implies for living in the digital world.

  4. EASTERN UGANDA

    African Journals Online (AJOL)

    EVALUATION OF SELECTED ELITE POTATO GENOTYPES IN. EASTERN ... Significant

  5. Knowledge Sharing

    DEFF Research Database (Denmark)

    Holdt Christensen, Peter

    The concept of knowledge management has, indeed, become a buzzword that every single organization is expected to practice and live by. Knowledge management is about managing the organization's knowledge for the common good of the organization -but practicing knowledge management is not as simple...... as that. This article focuses on knowledge sharing as the process seeking to reduce the resources spent on reinventing the wheel.The article introduces the concept of time sensitiveness; i.e. that knowledge is either urgently needed, or not that urgently needed. Furthermore, knowledge sharing...... is considered as either a push or pull system. Four strategies for sharing knowledge - help, post-it, manuals and meeting, and advice are introduced. Each strategy requires different channels for sharing knowledge. An empirical analysis in a production facility highlights how the strategies can be practiced....

  6. An aftereffect of global warming on tropical Pacific decadal variability

    Science.gov (United States)

    Zheng, Jian; Liu, Qinyu; Wang, Chuanyang

    2017-05-01

    Studies have shown that global warming over the past six decades can weaken the tropical Pacific Walker circulation and maintain the positive phase of the Interdecadal Pacific Oscillation (IPO). Based on observations and model simulations, another aftereffect of global warming on IPO is found. After removing linear trends (global warming signals) from observations, however, the tropical Pacific climate still exhibited some obvious differences between two IPO negative phases. The boreal winter (DJF) equatorial central-eastern Pacific sea surface temperature (SST) was colder during the 1999-2014 period (P2) than that during 1961-1976 (P1). This difference may have been a result of global warming nonlinear modulation of precipitation; i.e., in the climatological rainy region, the core area of the tropical Indo-western Pacific warm pool receives more precipitation through the "wet-get-wetter" mechanism. Positive precipitation anomalies in the warm pool during P2 are much stronger than those during P1, even after subtracting the linear trend. Corresponding to the differences of precipitation, the Pacific Walker circulation is stronger in P2 than in P1. Consequent easterly winds over the equatorial Pacific led to a colder equatorial eastern-central Pacific during P2. Therefore, tropical Pacific climate differences between the two negative IPO phases are aftereffects of global warming. These aftereffects are supported by the results of coupled climate model experiments, with and without global warming.

  7. Paleotsunamis in Eastern Taiwan

    Science.gov (United States)

    Yen, Jiun-Yee; Yu, Neng-Ti; Hirakawa, Kazuomi; Chyi, Shyh-Jeng; Huang, Shao-Yi

    2017-04-01

    Although Taiwan is located in the active collision zone between Eurasian and the Philippine Sea plate with very high seismicity in and surrounding the island, and supposedly highly susceptible to tsunami hazard. However, there is no record of tsunami hazard in the past one hundred years, and only very few historical records show some possible extreme event occurred. Therefore study of tsunami was scarce in Taiwan. Although historical records do show possible tsunami events, the records were too sparse and incomplete to confidently reconstruct the paleotsunami events. In the past few years, numerical simulations based on possible tsunami-genic zones near Taiwan show that the island could be affected by the correctly directed tsunami. Nevertheless, there is no detail, scientific research of paleotsunami records yet in Taiwan. Our field survey in eastern Taiwan (facing the western Pacific Ocean) along the coast uncovered several outcrops contain gravels embedded in well-developed soil layers. The rounded meta-sandstone gravels are clearly beach-origin and were brought to their current location upon extreme wave events, which is composed of either volcanic-clastic deposits from nearby hills or organic soil layers formed locally. Our investigation indicates that there are at least 3 events in the northern half of eastern Taiwan and at least 2 events in southern part of eastern Taiwan. Although these outcrops are next to the shoreline and Taiwan is susceptible from typhoons, these gravels could be farther away from the beach at the time of their deposition due to current high retreat rate of the sea cliff. Further investigations are needed to delineate possible sources of tsunamis that caused the deposits.

  8. The geographic and demographic scope of shared sanitation: an analysis of national survey data from low- and middle-income countries.

    Science.gov (United States)

    Heijnen, Marieke; Rosa, Ghislaine; Fuller, James; Eisenberg, Joseph N S; Clasen, Thomas

    2014-11-01

    A large and growing proportion of the world's population rely on shared sanitation facilities that have historically been excluded from international targets due to concerns about acceptability, hygiene and access. In connection with a proposed change in such policy, we undertook this study to describe the prevalence and scope of households that report relying on shared sanitation and to characterise them in terms of selected socio-economic and demographic covariates. We extracted data from the most recent national household surveys of 84 low- and middle-income countries from Demographic and Health Surveys and Multiple Indicator Cluster Surveys. We describe the prevalence of shared sanitation and explore associations between specified covariates and reliance on shared sanitation using log-binomial regression. While household reliance on any type of shared sanitation is relatively rare in Europe (2.5%) and the Eastern Mediterranean (7.7%), it is not uncommon in the Americas (14.2%), Western Pacific (16.4%) and South-East Asia (31.3%), and it is most prevalent in Africa (44.6%) where many shared facilities do not meet the definition of 'improved' even if they were not shared (17.7%). Overall, shared sanitation is more common in urban (28.6%) than in rural settings (25.9%), even after adjusting for wealth. While results vary geographically, people who rely on shared sanitation tend to be poorer, reside in urban areas and live in households with more young children and headed by people with no formal education. Data from 21 countries suggest that most sharing is with neighbours and other acquaintances (82.0%) rather than the public. The determinants of shared sanitation identified from these data suggest potential confounders that may explain the apparent increased health risk from sharing and should be considered in any policy recommendation. Both geographic and demographic heterogeneity indicate the need for further research to support a change in policies. © 2014

  9. Current meter and other data collected using current meter casts from R/V RESEARCHER and R/V CALANUS in the Atlantic and Pacific Ocean as part of the Eastern Pacific Ocean Circulation Study (EPOCS) and Subtropical Atlantic Current Study (STACS), 23 March 1983 - 19 November 1986 (NODC Accession 8700226)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter and other data were collected using current meter casts from R/V RESEARCHER and R/V CALANUS in the Atlantic and Pacific Ocean from March 23, 1983 to...

  10. Tropical cyclone statistics in the Northeastern Pacific

    OpenAIRE

    Romero Vadillo, E; Zaitsev, Oleg; Morales Pérez., R

    2007-01-01

    The principal area of tropical cyclogenesis in the tropical eastern Pacific Ocean is offshore in the Gulf of Tehuantepec, between 8 and 15° N, and most of these cyclones move towards the west and northwest during their initial phase. Historical analysis of tropical cyclone data in the Northeastern (NE) Pacific over the last 38 years (from 1966 to 2004) shows a mean of 16.3 tropical cyclones per year, consisting of 8.8 hurricanes and 7.4 tropical storms. The analysis shows great geographical v...

  11. 75 FR 8674 - Western Pacific Fishery Management Council; Public Meetings

    Science.gov (United States)

    2010-02-25

    ... Spatial Planning, coral reef ecosystem threats, truth in science, Western and Central Pacific Fisheries.... NOAA Draft Catch Shares Policy E. National Ocean Policy and Marine Spatial Planning F. Local, National... the Pacific Islands Fisheries Science Center Director 5. Program Planning A. ACLs...

  12. 基于海表温度和海面高度的东太平洋大眼金枪鱼渔场预测%Forecasting ofBigeye tuna fishing ground in the Eastern Pa-cific Ocean based on sea surface temperature and sea surface height

    Institute of Scientific and Technical Information of China (English)

    沈智宾; 陈新军; 汪金涛

    2015-01-01

    The technology research of fishing ground prediction for bigeye tuna in the eastern Pacific and the estab-lishment based on fishing ground prediction model of multiple environmental factors are of great importance for the efficient development and utilization of its resources. Bigeye tuna,Thunnus obesus, is one of the important tunas in the Eastern Pacific Ocean, and also one of the main fishing targets for Chinese tuna longline fishery. In this paper, based on the catch data from longline fishery in the areas (20°N~30°S and 85°~155°W) of Eastern Pacific Ocean during 2009~2011 and the environmental data from remote sensing including sea surface temperature (SST) and sea surface height (SSH), the catch is considered as the suitability index, and the suitability curves based on SST and SSH for one quarter were established by using a non-linear regression. The habitat suitability index model was set up by using arithmetic mean model (AMM), and was validated by using the actual catch data in 2012. The results showed that the fishing ground of bigeye tuna is located in the waters with 24~29℃ SST and 0.4~0.8 m SSH. The SI curve of each factor by using nonlinear regression is significant (P<0.05). Forecast accuracy of fisheries center is 63%, which is a high forecast accuracy. This forecasting model will play a guide role for fishing fleets in the tuna longline fishery.%开展东太平洋大眼金枪鱼(Thunnus obesus)渔场预报技术研究,建立基于多环境因子渔场预报模型,将对该资源的高效开发和利用具有重要的意义。作者根据2009~2011年东太平洋海域(20°N~35°S、85°W~155°W)延绳钓生产统计数据,结合海洋遥感获得的表温(SST)和海面高度(SSH)的数据,运用一元非线性回归方法,以渔获量为适应性指数,按季度分别建立了基于SST和SSH的大眼金枪鱼栖息地适应性指数,采用算术平均法获得基于 SST 和 SSH 环境因子的栖息

  13. AFSC/NMML: North Pacific Right Whale Photo-ID Catalog

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The eastern population of the North Pacific right whale (Eubalaena japonica) is the most endangered stock of whales in the world, with recent abundance estimates...

  14. AFSC/RACE/GAP/Nichol: Archival tag depth and temperature data from Pacific cod

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data from 250 recaptured (624 released) depth and temperature recording archival (data storage) tags attached to Pacific cod off Kodiak Island and in the eastern...

  15. The relationship between ENSO and spatio-temporal distribution of CPUE of yellowfin tuna(Thunnus albacares) by purse seine in the Eastern Pacific Ocean%ENSO现象与东太平洋黄鳍金枪鱼围网CPUE时空分布的关系

    Institute of Scientific and Technical Information of China (English)

    代丹娜; 刘洪生; 戴小杰; 田思泉

    2011-01-01

    Yellowfin tuna(Thunnus albacares) is a major target species of the tuna purse seine fishery in the Eastern Pacific Ocean.Based on yellowfin tuna purse-seine fisheries data in the Eastern Pacific Ocean(30°N-25°S,75°W-145°W)from 1975 to 2004 and the corresponding Nino3 index(sea surface temperature anomaly),the relationship between ENSO and yellowfin tuna stock abundance and its spatio-temporal distribution are analyzed by using grey relationship analysis method in this study.Preliminary results indicate that ENSO episodes affect the stock abundance and spatio-temporal distribution of yellowfin tuna significantly.During El Nino periods,the fishing gravity center moves to the east and the north,whereas to the west during La Nina periods.There is a negative relationship between Nino3 index and CPUE.Furthermore,there is a siginifcantly regular annual change for the location of fishing gravity center.In the spring and summer,the fishing gravity center turns to the west and to the north,but it moves to the east and the south in the autumn and winter.The CPUE of the spring and summer is higher than that of the autumn and winter.%黄鳍金枪鱼是东太平洋金枪鱼围网渔业中的主要渔获种类之一。根据1975-2004年东太平洋(30°N~25°S,75°W~145°W)黄鳍金枪鱼围网生产统计资料和相应年份的Nino3区的指数,利用灰色关联度方法对ENSO现象与黄鳍金枪鱼资源丰度及时空变化的关系进行了分析。研究结果发现,ENSO现象对东太平洋黄鳍金枪鱼围网资源丰度及时空分布有显著影响,在大部分厄尔尼诺年时,黄鳍金枪鱼围网作业重心会向东、向北移;而拉尼娜年则向西移。Nino3指数与单位捕捞努力量渔获量(CPUE)存在负相关关系。此外,黄鳍金枪鱼

  16. PRELIMINARY STUDY ON FISHERIES BIOLOGY OF DOSIDICUS GIGAS IN THE WATERS NEAR THE EQUATOR OF EASTERN PACIFIC OCEAN%东太平洋赤道附近海域茎柔鱼(Dosidicus gigas)渔业生物学的初步研究

    Institute of Scientific and Technical Information of China (English)

    陈新军; 李建华; 易倩; 刘必林; 杨铭霞; 陆化杰

    2012-01-01

    Based on the samples of 1178 squids in total from Chinese squid jigging vessels near the equator of the eastern Pacific in 2011, the biological characteristics of Dosidicus gigas were studied. The results showed that the range of mantle length was from 201 to 421mm and the average attained 290mm, the dominant mantle length ranged from 260 to 320mm. Body weight was from 200g to 2650g and the average attained 1000g, the dominant body weight ranged from 600 to 1000g. The equation of the relationship between mantle length and body weight was fitted by power exponent. The sexual ratio of female to male was 2.59 : 1. The sexual maturity stage dominated I and II. The length and weight of nidamental gland of D. gigas increased with the growth of gland maturity. And the mantle length of first maturity of females was 397.2mm. The feeding stage dominated 0-1. It can be found that D. gigas near the equator is obvious different from that in the Gulf of California and waters off Chile, Peru and Costa Rica. We can conclude that the population of D. gigas near the equator of the eastern Pacific belongs to small group.%根据2011年东太平洋赤道附近海域探捕期间采集的1178尾茎柔鱼样本,进行了茎柔鱼的生物学特性研究。结果表明:茎柔鱼胴长范围为201-421mm,平均胴长为290mm,优势胴长为260—320mm;体重范围为200-2650g,平均体重为1000g,优势体重为600-1000g;胴长与体重关系呈幂指数关系;雌、雄性比为2.59:1;性腺成熟度以I、Ⅱ期为主;缠卵腺长和缠卵腺重随着性腺的成熟而逐步增大;雌性初次性成熟胴长为397.2mm;摄食等级以0—1级为主;与其它海域相比,该海域茎柔鱼个体差异明显,主要为小型群体。

  17. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon (Oceanography data)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  18. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon (TSG-thermosalinigraph data)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  19. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  20. AFSC/ABL: Eastern Bering Sea (EMA-BASIS) Zooplankton data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  1. Stock structure and demographic history of the Indo-West Pacific mud crab Scylla serrata

    Science.gov (United States)

    Fratini, Sara; Ragionieri, Lapo; Cannicci, Stefano

    2010-01-01

    The increasing exploitation of mangrove forests, without any sustainable planning, has been seriously compromising the survival of this ecosystem and of its exclusive resources. Scylla serrata is one of the most commercially exploited crabs inhabiting mangroves and estuaries of the Indo-Pacific region. This species is extensively harvested, mainly for selling to the tourist market, and, as a consequence, its populations are in constant decline. The aim of the present study was to assess the level of genetic exchange of S. serrata within the Western Indian Ocean (WIO), using a population genetic structure approach. To achieve this goal, we reconstructed the intra-specific geographic pattern of genetic variation by partial sequencing the mitochondrial DNA cytochrome oxidase subunit I, in samples from seven mangrove sites of the WIO. Our data set then encompassed all the sequences for the same genetic marker deposited in Genbank and corresponding to samples from South East Asia, Australia and some Pacific Islands: this allowed us to estimate the level of connectivity among S. serrata populations within its distribution area. Our results show that an unique Scylla serrata metapopulation exists within the WIO; while throughout the entire Indo-Pacific region at least three distinct genetic stocks occur, corresponding to well-defined geographic regions (WIO, Eastern Australia and Pacific Ocean, North-Western Australia). South East China appears as the depositary of the most ancient haplotype and at the present time shares a haplotype with the Red Sea. The WIO populations show the signature of recent population bottlenecks, as expected for populations deeply exploited in a recent past. On the basis of our results, we can conclude that both the S. serrata populations and their habitats, i.e. mangrove forests and estuaries, of the WIO require future management and conservation regulations to avoiding overexploitation of this important key predator and marketable resource.

  2. The Circum-Pacific Teleconnection Pattern in Meridional Wind in the High Troposphere

    Institute of Scientific and Technical Information of China (English)

    WANG Huijun

    2005-01-01

    The Circum-Pacific Teleconnection Pattern (CPTP) is revealed in the meridional wind in the high troposphere via an emprirical orthogonal function (EOF) and correlation analysis on NCEP/NCAR reanalysis data. The CPTP is found to be composed of the North Pacific-North American teleconnection pattern (PNA), the South Pacific-South American teleconnection pattern (PSA), and the teleconnection patterns over the tropical western Pacific and the tropical eastern Pacific (or, Central America, or, tropical Atlantic). There is substantial interannual variability of the CPTP and a typical CPTP can be detected in some years. It is speculated that the zonal wind anomalies over the equatorial region in the western and eastern sides of the Pacific may play a role in linking the two hemispheres. The anomalous convection activities in the Tropics are plausible triggering factors for the zonal wind anomalies that are responsible for the composition of the CPTP.

  3. 78 FR 65887 - International Fisheries; Pacific Tuna Fisheries; 2013 Bigeye Tuna Longline Fishery Closure in the...

    Science.gov (United States)

    2013-11-04

    ... National Oceanic and Atmospheric Administration 50 CFR Part 300 RIN 0648-XC922 International Fisheries; Pacific Tuna Fisheries; 2013 Bigeye Tuna Longline Fishery Closure in the Eastern Pacific Ocean AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA),...

  4. Shared Memories?

    DEFF Research Database (Denmark)

    Wæhrens, Anne

    2011-01-01

    This paper analyses how the memory of the Holocaust has been addressed in the European Parliament from 1989 to 2009. I identify two major changes that occurred in the 1990s and after the 2004 enlargement of the European Union respectively. In the 1990s the war in Bosnia and the question of restit......This paper analyses how the memory of the Holocaust has been addressed in the European Parliament from 1989 to 2009. I identify two major changes that occurred in the 1990s and after the 2004 enlargement of the European Union respectively. In the 1990s the war in Bosnia and the question...... of restitution universalised the memory of the Holocaust and made it present. The 2004 enlargement brought the memory of Soviet Communism into the Union and made it a central task to construct a community of memory that includes both the memory of the Holocaust and of Soviet Communism. The analysis also...... identifies what seems to be a political memory split between Left and Right; and it shows that the time might not be ripe for a shared European memory....

  5. First record of morphological abnormality in embryos of Urotrygon rogersi (Jordan & Starks, 1895 (Myliobatiformes: Urotrygonidae in the Tropical Eastern Pacific Primer registro de anomalía morfológica en embriones de Urotrygon rogersi (Jordan & Starks, 1895 (Myliobatiformes: Urotrygonidae en el Pacífico oriental tropical

    Directory of Open Access Journals (Sweden)

    Paola A Mejía-Falla

    2011-01-01

    Full Text Available This is the first report of morphological abnormalities in embryos of Roger's roundray Urotrygon rogersi in the Tropical Eastern Pacific. The embryos of two pregnant females caught in artisanal shrimp trawl nets had incomplete, deformed pectoral fins that were separated from the head along the anterior margin. Moreover, one of the embryos presented a fm-like extensión in the dorsal surface. Although the mouths of the embryos were normal and well-formed, the malformations in the pectoral fins could affect their mobility, limiting their capacity to capture preys and escape of predators.Este estudio constituye el primer registro de anormalidad morfológica en embriones de Urotrygon rogersi en el Pacífico oriental tropical. Dos hembras grávidas capturadas con redes de arrastre de camarón en pesca artesanal, presentaron embriones con aletas pectorales deformes e incompletas, y con el margen anterior separado de la cabeza; uno de ellos también presentó una extensión a manera de aleta en la superficie dorsal. Aunque la boca de los embriones fue normal y bien desarrollada, las malformaciones en las aletas pectorales podrían afectar su movilidad, limitando así la capacidad para capturar sus presas y escapar de pre dadores.

  6. On North Pacific circulation and associated marine debris concentration.

    Science.gov (United States)

    Howell, Evan A; Bograd, Steven J; Morishige, Carey; Seki, Michael P; Polovina, Jeffrey J

    2012-01-01

    Marine debris in the oceanic realm is an ecological concern, and many forms of marine debris negatively affect marine life. Previous observations and modeling results suggest that marine debris occurs in greater concentrations within specific regions in the North Pacific Ocean, such as the Subtropical Convergence Zone and eastern and western "Garbage Patches". Here we review the major circulation patterns and oceanographic convergence zones in the North Pacific, and discuss logical mechanisms for regional marine debris concentration, transport, and retention. We also present examples of meso- and large-scale spatial variability in the North Pacific, and discuss their relationship to marine debris concentration. These include mesoscale features such as eddy fields in the Subtropical Frontal Zone and the Kuroshio Extension Recirculation Gyre, and interannual to decadal climate events such as El Niño and the Pacific Decadal Oscillation/North Pacific Gyre Oscillation. Published by Elsevier Ltd.

  7. A Sea Change : Exotics In the eastern Mediterranean.

    OpenAIRE

    Galil, B.S.; Zenetos, A

    2002-01-01

    The eastern Mediterranean is susceptible to biological invasions because of its placement between the Atlantic, Pontic and Erythrean regions, busy maritime traffic, and lagoons and bays that are crowded with fish and shellfish farms. However, the greatest influx of invaders resulted from the opening of the Suez Canal in 1869, which allowed entry of Indo-Pacific and Erythrean biota. Exotic macro phytes, invertebrates and fish are found in most coastal habitats in the eastern Med...

  8. Macroinvertebrados dulceacuícolas de la Isla del Coco, Costa Rica: especies y comparación con otras islas del Pacífico Tropical Oriental Freshwater macroinvertebrates from Cocos Island, Costa Rica: species and comparison with other islands of the Eastern Tropical Pacific

    Directory of Open Access Journals (Sweden)

    Pablo E. Gutiérrez-Fonseca

    2013-06-01

    Full Text Available La Isla del Coco es una isla oceánica localizada en el Pacífico Tropical Oriental a unos 492km de Cabo Blanco. La isla cuenta con un área terrestre de 24km² y un área marina protegida de 9 640km². Fue declarada Parque Nacional en 1978 y Patrimonio de la Humanidad por la UNESCO en 1997. Se realizó una gira de recolecta del 22 de mayo al 12 junio 2008. Se recolectaron macroinvertebrados acuáticos en 20 tramos de tres ríos (Genio, Chatham y Sucio y dos quebradas (Minuto y quebrada sin nombre atrás de estación de guarda parques. En 13 sitios se toma- ron parámetros fisicoquímicos. En total se recolectaron 455 individuos de 20 táxones de 15 familias de insectos acuáticos y otros macroinvertebrados. La familia Staphylinidae presentó la mayor abundancia seguida por Chironomidae, los dípteros fueron el orden con mayor riqueza taxonómica. Una relación entre distancia y número de familias se observó apoyando en parte la Teoría de Biogeografía de Islas. La relación mejoró al corregir área con elevación, indicando que islas montañosas tenían alta riqueza, posiblemente debido a la mayor intercepción de nubes que alimentan los ambientes dulceacuícolas que favorecen el establecimiento de la fauna acuática. Las variables ambientales fueron similares en todos los sitios.Cocos Island is an oceanic island in the Eastern Pacific, at 496km from Cabo Blanco, Costa Rica. This 24km² island is surrounded by a protected marine area of 9 640km². It was declared National Park in 1978 and a World Heritage by UNESCO in 1997. Freshwater macroinvertebrate fauna was collected in 20 sites covering three rivers (Genio, Chatam and Sucio and two creeks (Minuto and an unnamed creek behind the park rangers’ house. Tank bromeliads or phytotelmata were also examined for aquatic macroinvertebrates. Physicochemical parameters were determined in 13 study sites. Additionally, a comparison with other islands in the Eastern Tropical Pacific was conducted

  9. Ctenophores from the Oaxaca coast, including a checklist of species from the Pacific coast of Mexico.

    Science.gov (United States)

    Ruiz-Escobar, Fernando; Valadez-Vargas, Diana K; Oliveira, Otto M P

    2015-03-20

    Ctenophores are poorly known in the tropical eastern Pacific, including the southern coast of Mexico. Previous records of ctenophores along the Pacific coast have been provided mainly from northern waters. For the coast of Oaxaca state, their occurrence has only been mentioned before at phylum level. In this paper, we provide the first three records of ctenophores for the Oaxacan coast, which represent new records of Beroe forskalii and Bolinopsis vitrea as well as the first record of Ocyropsis maculata in the tropical eastern Pacific. Descriptions of these three species, as well as a checklist of the ctenophores from the west coast of Mexico are provided.

  10. Madagascar corals reveal Pacific multidecadal modulation of rainfall since 1708

    Directory of Open Access Journals (Sweden)

    C. A. Grove

    2012-03-01

    Full Text Available The Pacific Ocean modulates Australian and North American rainfall variability on multidecadal timescales, in concert with the Pacific Decadal Oscillation (PDO. It has been suggested that Pacific decadal variability may also influence Indian Ocean surface temperature and rainfall in a far-field response, similar to the El Niño Southern Oscillation (ENSO on interannual timescales. However, instrumental records of rainfall are too short and too sparse to confidently assess such multidecadal climatic teleconnections. Here, we present four climate archives spanning the past 300 yr from giant Madagascar corals. We decouple 20th century human deforestation effects from rainfall induced soil erosion using spectral luminescence scanning and geochemistry. The corals provide the first evidence for Pacific decadal modulation of rainfall over the Western Indian Ocean. We find that positive PDO phases are associated with increased Indian Ocean temperatures and rainfall in Eastern Madagascar, while precipitation in Southern Africa and Eastern Australia declines. Consequently, the negative PDO phase that started in 1998 should lead to reduced rainfall over Eastern Madagascar and increased precipitation in Southern Africa and Eastern Australia. We conclude that the PDO has important implications for future multidecadal variability of African rainfall, where water resource management is increasingly important under the warming climate.

  11. Dengue virus type 3, South Pacific Islands, 2013.

    Science.gov (United States)

    Cao-Lormeau, Van-Mai; Roche, Claudine; Musso, Didier; Mallet, Henri-Pierre; Dalipanda, Tenneth; Dofai, Alfred; Nogareda, Francisco; Nilles, Eric J; Aaskov, John

    2014-06-01

    After an 18-year absence, dengue virus serotype 3 reemerged in the South Pacific Islands in 2013. Outbreaks in western (Solomon Islands) and eastern (French Polynesia) regions were caused by different genotypes. This finding suggested that immunity against dengue virus serotype, rather than virus genotype, was the principal determinant of reemergence.

  12. Biophysical Feedbacks in the Tropical Pacific.

    Science.gov (United States)

    Marzeion, Ben; Timmermann, Axel; Murtugudde, Ragu; Jin, Fei-Fei

    2005-01-01

    This study explores the influence of phytoplankton on the tropical Pacific heat budget. A hybrid coupled model for the tropical Pacific that is based on a primitive equation reduced-gravity multilayer ocean model, a dynamic ocean mixed layer, an atmospheric mixed layer, and a statistical atmosphere is used. The statistical atmosphere relates deviations of the sea surface temperature from its mean to wind stress anomalies and allows for the rectification of the annual cycle and the El Niño-Southern Oscillation (ENSO) phenomenon through the positive Bjerknes feedback. Furthermore, a nine-component ecosystem model is coupled to the physical variables of the ocean. The simulated chlorophyll concentrations can feed back onto the ocean heat budget by their optical properties, which modify solar light absorption in the surface layers. It is shown that both the surface layer concentration as well as the vertical profile of chlorophyll have a significant effect on the simulated mean state, the tropical annual cycle, and ENSO. This study supports a previously suggested hypothesis (Timmermann and Jin) that predicts an influence of phytoplankton concentration of the tropical Pacific climate mean state and its variability. The bioclimate feedback diagnosed here works as follows: Maxima in the subsurface chlorophyll concentrations lead to an enhanced subsurface warming due to the absorption of photosynthetically available shortwave radiation. This warming triggers a deepening of the mixed layer in the eastern equatorial Pacific and eventually a reduction of the surface ocean currents (Murtugudde et al.). The weakened south-equatorial current generates an eastern Pacific surface warming, which is strongly enhanced by the Bjerknes feedback. Because of the deepening of the mixed layer, the strength of the simulated annual cycle is also diminished. This in turn leads to an increase in ENSO variability.

  13. A new species of symbiotic palaemonid shrimp of the genus Pseudocoutierea Holthuis, 1951 (Decapoda: Caridea: Palaemonidae) from the eastern Gulf of Mexico, with an updated key for the identification of species of the genus.

    Science.gov (United States)

    Ramos-Tafur, Gabriel E; Lemaitre, Rafael

    2016-10-06

    A new species of symbiotic palaemonid shrimp of the genus Pseudocoutierea Holthuis, 1951, is described based on a specimen collected in the eastern Gulf of Mexico, off the southwest coast of Florida. Pseudocoutierea stephanieae sp. nov., is the seventh known in this genus, and morphologically most similar to P. antillensis Chace, 1972, and P. conchae Criales, 1981, from the western Atlantic, and P. elegans Holthuis, 1952, from the eastern Pacific, all sharing an expanded rostral base or eaves that terminate supra-distally in an acute tooth. This new species can be separated by: the presence of an epigastric knob or tubercle on the anterior mid-dorsal third of the carapace, which is absent in all other congeneric species; the shape of the pterygostomial sinus, which is shallow in this new species, whereas it is deep and well defined in all other congeneric species. An updated dichotomous key to species of Pseudocoutierea is presented.

  14. Global Warming Attenuates the Tropical Atlantic-Pacific Teleconnection.

    Science.gov (United States)

    Jia, Fan; Wu, Lixin; Gan, Bolan; Cai, Wenju

    2016-02-03

    Changes in global sea surface temperature (SST) since the end of last century display a pattern of widespread warming intercepted by cooling in the eastern equatorial Pacific and western coasts of the American continent. Studies have suggested that the cooling in the eastern equatorial Pacific may be partly induced by warming in the North Atlantic. However, it remains unknown how stable this inter-tropical teleconnection will be under global warming. Here we show that the inter-tropical teleconnection from the tropical Atlantic to Pacific weakens substantially as the CO2 concentration increases. This reduced impact is related to the El Niño-like warming of the tropical Pacific mean state, which leads to limited seasonal migration of the Pacific inter-tropical convergence zone (ITCZ) and weakened ocean heat transport. A fast decay of the tropical Atlantic SST anomalies in a warmer climate also contributes to the weakened teleconnection. Our study suggests that as greenhouse warming continues, the trend in the tropical Pacific as well as the development of ENSO will be less frequently interrupted by the Atlantic because of this attenuation. The weakened teleconnection is also supported by CMIP5 models, although only a few of these models can capture this inter-tropical teleconnection.

  15. Features of Western Pacific Subtropical High (WPSH)Associated with Drought/Flood in Summer over the Eastern Part of Southwest China%西南地区东部夏季旱涝的西太平洋副高特征

    Institute of Scientific and Technical Information of China (English)

    李永华; 青吉铭; 李强; 向波

    2013-01-01

    Based on the NCEP/NCAR reanalysis monthly data, the circulation characteristic index values given by the National Climate Center and the daily precipitation data of 20 meteorological observation stations in the eastern part of Southwest China from 1959 to 2006, the features of western Pacific subtropical high (WPSH) associated with drought/flood in summer over the eastern part of Southwest China are analyzed. The results show that WPSH and summer precipitation in Eastern Southwest China are characterized by an obvious inter-annual and inter-decadal variability. A positive relationship exists between the area and intensity indexes of WPSH in summer, and a significant negative correlation is present between area or intensity index and westward ridge index. And a positive relationship lies between ridge position and north ridge index. The flood-drought over Eastern Southwest China is closely associated with the ridge position of WPSH but not with the other indexes such as area and intensity indexes. Generally speaking, summer drought is more likely to occur in Eastern Southwest China with the ridge position leaning to the north, while summer flood is more liable with the ridge position leaning to the south. It is (not) propitious to appearance of circulation making for summer rainfall in Eastern Southwest China. Furthermore the vapor transport and convergent anabatic velocity strengthening (weakening), and cold air active (fallow) come from north when the ridge position leans to the south (north). The summer flood-drought in Eastern Southwest China is significantly influenced by WPSH, and by other factors as well. In fact, it results from the influence of many factors.%利用1959-2006年西南地区东部20个测站逐日降水量资料和NCEP/NCAR再分析月平均资料以及国家气候中心提供的环流特征量资料,分析了西南地区东部夏季旱涝年的西太平洋副热带高压特征.结果表明:西南地区东部夏季降水(旱涝)及西太平

  16. The Role of the Halted Baroclinic Mode at the Central Equatorial Pacific in El Ni(n)o Event

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The role of halted "baroclinic modes" in the central equatorial Pacific is analyzed. It is found that dominant anomaly signals corresponding to "baroclinic modes" occur in the upper layer of the equatorial Pacific, in a two-and-a-half layer oceanic model, in assimilated results of a simple OGCM and in the ADCP observation of TAO. A second "baroclinic mode" is halted in the central equatorial Pacific corresponding to a positive SST anomaly while the first "baroclinic mode" propagates eastwards in the eastern equatorial Pacific. The role of the halted second "baroclinic mode" in the central equatorial Pacific is explained by a staged ocean-atmosphere interaction mechanism in the formation of El Ni(n)o: the westerly bursts in boreal winter over the western equatorial Pacific generate the halted second "baroclinic mode" in the central equatorial Pacific, leading to the increase of heat content and temperature in the upper layer of the central Pacific which induces the shift of convection from over the western equatorial Pacific to the central equatorial Pacific; another wider, westerly anomaly burst is induced over the western region of convection above the central equatorial Pacific and the westerly anomaly burst generates the first "baroclinic mode"propagating to the eastern equatorial Pacific, resulting in a warm event in the eastern equatorial Pacific.The mechanism presented in this paper reveals that the central equatorial Pacific is a key region in detecting the possibility of ENSO and, by analyzing TAO observation data of ocean currents and temperature in the central equatorial Pacific, in predicting the coming of an El Ni(n)o several months ahead.

  17. Signal propagations and linkages of subsurface temperature anomalies in the tropical Pacific and Indian Ocean

    Institute of Scientific and Technical Information of China (English)

    QIAN Weihong; HU Haoran

    2005-01-01

    The propagation characteristics of signals along different zonal-time profiles are analyzed using surface and subsurface temperature anomalies over the tropical Pacific and Indian oceans. Analyses show that there are intrinsic relationships between El Nino events in the eastern equatorial Pacific and dipole events in the equatorial Indian Ocean. In the region of tropical North Pacific between the equator and 16°N, there is a circle of propagation of subsurface temperature anomalies. El Nino events only happen when the warm subsurface signals reach the eastern equatorial Pacific. Dipole events are characterized when a warm subsurface signal travels along off-equatorial Indian Ocean to the western boundary. From these analyses, we believe that subsurface temperature anomalies can be considered to be the oceanographic early signal to forecast El Nino events in Pacific Ocean and dipole events in Indian Ocean, respectively.

  18. Research on the Propagation Acting of the Equatorial Planetary Waves on the Western Equatorial Pacific Warm Pool Heat

    Institute of Scientific and Technical Information of China (English)

    Shi Qiang; Xu Jianping; Zhu Bokang

    2003-01-01

    Based on the long-term buoy data from the Tropical Atmosphere Ocean ( TAO ) array during the TOGA ( Tropical Ocean and Global Atmosphere) Program (1980-1996), the propagation acting of the Equatorial planetary waves on the Western Equatorial Pacific warm pool heat is analyzed. Results show that the zonal heat transmission in the Western Equatorial Pacific takes palace mainly in the subsurface water and spreads eastwards along the thermocline; while the seasonal westward-spreading heat change structure occurs in the mixed layers in the middle and western Pacific. The standing-form transmission in the western Pacific appears in the thermocline layer, while in the eastern pacific, it exists in the mixed layer as well as in the thermocline layer. The standing-form and eastward-spreading sign of zonal heat transmitting in the upper water is predominant and strong, and the westward sign is weak.The component force of Kelvin Equatorial wave pressure runs through the western and eastern Equatorial pacific, and transmits heat energy eastwards. And the heat transmitted by zonal current component occurs mostly in the western Pacific; The heat transmitted by the component force of Rossby wave pressure mainly appears in the eastern and middle areas of the Pacific, while the zonal current component transmitting occurs mainly in the western Pacific; Mixed-Rossby gravity wave's action on the zonal current is stronger than that of the thermocline layer. In the mean state, the standing wave model of Equatorial Pacific up layer ocean temperature confines the transport of western Pacific warm pool heat to the eastern Pacific. Under abnormal conditions, the standing wave model of Equatorial Pacific up layer ocean temperature weakens, the eastwardly transmitting model enhances, and subsequently the El Ni n o event occurs.

  19. Asia-Pacific lube oil markets

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, N.

    2001-06-01

    An overview of the Asia-Pacific (AP) lubricating oils market, its special characteristics, and its role in the global economy are presented. In the 'boom and bust' years of 1997-1999, the Asia-Pacific market was even bigger then the US market. For the short-term, the scenario is surplus capacity and poor margins, but in the long term there is enormous potential for growth. How fuel demand and quality is related to engine type is discussed. The three basic grades of baseoils are described, and the Asia-Pacific lube demand and the Asia-Pacific lube oil supply are discussed. There are 15 diagrams giving data on: (i) finished lubes in world markets as a percentage of total; (ii) how lube demand follows GDP per capita in Asia; (iii) AP baseoil capacity relationships; (iv) AP baseoil disposition by end use; (v) AP changing shares of baseoil demand; (vi) AP finished lube demand by subregion; (vii) AP finished lube demand growth, indexed; (viii) AP baseoil capacity by region; Singapore baseoil vs. Dubai crude prices, 1992-99; (ix) Singapore baseoil vs. crude prices, 1992-99; (x) AP baseoil deficit moved to surplus; (xi) AP baseoil production; (xii) East Asia net percentage change in lube sales, 1997-1999. (xiii) Southeast Asia net percentage change in lube sales, 1997-1999; (xiv) South East Asia and Australia net percentage change in lube sales, 1997-1999 and (xv) Asia-Pacific major lube marketers.

  20. 75 FR 5745 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2010-02-04

    ... action will be announced by NMFS via an update to the recreational halibut hotline. If after the Labor... the Labor Day weekend, the IPHC, NMFS, and ODFW will consult to determine whether increasing the... to have an IPHC license to retain halibut. Specific data on the economics of halibut...

  1. 76 FR 14300 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2011-03-16

    ...-mail at peggy.murphy@noaa.gov ; or, for waters off the U.S. West Coast, Sarah Williams, 206-526-4646, e-mail at sarah.williams@noaa.gov . SUPPLEMENTARY INFORMATION: Background The IPHC has promulgated... authority under the Halibut Act. The PFMC also exercises authority in a CSP allocating halibut among...

  2. 78 FR 16423 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2013-03-15

    .... Regulations at Sec. 300.65(c)(1) specify the GHLs based on the total constant exploitation yield (CEY... Washington Department of Fish and Wildlife (WDFW) and Oregon Department of Fish and Wildlife ] (ODFW... Fisheries and Oceans (DFO), Alaska Wildlife Troopers (AWT), United States Coast Guard (USCG),...

  3. 77 FR 5473 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2012-02-03

    ... incidental catch in the salmon troll fishery that is allocated 15 percent of the commercial allocation. The... troll seasons in Area 2A in accordance with regulations promulgated by NMFS. This fishery will occur... the salmon troll fishery (316 licenses in 2011); and the charterboat fleet (141 licenses in 2011)....

  4. 76 FR 2871 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2011-01-18

    ... catch in the salmon troll fishery that is allocated 15 percent of the commercial allocation. The... is authorized during salmon troll seasons in Area 2A in accordance with regulations promulgated by... sablefish fishery; incidental halibut caught in the salmon troll fishery (233 licenses in 2010); and...

  5. 78 FR 9660 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2013-02-11

    ... incidental catch in the salmon troll fishery that is allocated 15 percent of the commercial allocation. The...), incidental halibut catch in the salmon troll fishery, adjust the months for the incidental take fishery from...), and paragraph (7) of section 11, an incidental catch fishery is authorized during salmon troll...

  6. 75 FR 13024 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2010-03-18

    ... fishery during the salmon troll fishery specified in paragraph (3) of section 8. (5) A license issued in... incidental commercial fishery during the salmon troll season in Area 2A must have its ``Application for... salmon troll seasons in Area 2A in accordance with regulations promulgated by NMFS. (4) The...

  7. 77 FR 16740 - Pacific Halibut Fisheries; Catch Sharing Plan

    Science.gov (United States)

    2012-03-22

    ... factors, including timing of halibut migration and spawning, marketing for seasonal holidays, and interest... Alaska. (7) Section 24 applies to Aboriginal groups fishing for food, social and ceremonial purposes in...; Federal, State, United States treaty Indian, and Provincial fishery officials; and the media. 6...

  8. 77 FR 49863 - Pacific Imperial Railroad, Inc.-Change in Operator Exemption-Rail Line of San Diego and Arizona...

    Science.gov (United States)

    2012-08-17

    ... San Diego and Arizona Eastern Railway Company Pacific Imperial Railroad, Inc. (PIR), a noncarrier, has... is owned by San Diego and Arizona Eastern Railway Company (SD&AE). The agreement provides for a... Line to PIR, with the consent of SD&AE, its parent, San Diego Metropolitan Transit Development Board...

  9. 78 FR 4981 - Pacific Imperial Railroad, Inc.-Change in Operator Exemption-Rail Line of San Diego and Arizona...

    Science.gov (United States)

    2013-01-23

    ... San Diego and Arizona Eastern Railway Company Pacific Imperial Railroad, Inc. (PIR), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to change operators from San Diego & Imperial... Diego and Arizona Eastern Railway Company (SD&AE). The change in operators for the line is being...

  10. PACIFIC NORTHWEST CYBER SUMMIT

    Energy Technology Data Exchange (ETDEWEB)

    Lesperance, Ann M.; Matlock, Gordon W.; Becker-Dippmann, Angela S.; Smith, Karen S.

    2013-08-07

    On March 26, 2013, the Snohomish County Public Utility District (PUD) and the U.S. Department of Energy’s (DOE’s) Pacific Northwest National Laboratory (PNNL) jointly hosted the Pacific Northwest Cyber Summit with the DOE’s Office of Electricity Delivery and Energy Reliability, the White House, Washington State congressional delegation, Washington State National Guard, and regional energy companies.

  11. Surgeons and suture zones: Hybridization among four surgeonfish species in the Indo-Pacific with variable evolutionary outcomes.

    Science.gov (United States)

    DiBattista, Joseph D; Whitney, Jonathan; Craig, Matthew T; Hobbs, Jean-Paul A; Rocha, Luiz A; Feldheim, Kevin A; Berumen, Michael L; Bowen, Brian W

    2016-08-01

    Closely related species can provide valuable insights into evolutionary processes through comparison of their ecology, geographic distribution and the history recorded in their genomes. In the Indo-Pacific, many reef fishes are divided into sister species that come into secondary contact at biogeographic borders, most prominently where Indian Ocean and Pacific Ocean faunas meet. It is unclear whether hybridization in this contact zone represents incomplete speciation, secondary contact, an evolutionary dead-end (for hybrids) or some combination of the above. To address these issues, we conducted comprehensive surveys of two widely-distributed surgeonfish species, Acanthurus leucosternon (N=141) and A. nigricans (N=412), with mtDNA cytochrome b sequences and ten microsatellite loci. These surgeonfishes are found primarily in the Indian and Pacific Oceans, respectively, but overlap at the Christmas and Cocos-Keeling Islands hybrid zone in the eastern Indian Ocean. We also sampled the two other Pacific members of this species complex, A. achilles (N=54) and A. japonicus (N=49), which are known to hybridize with A. nigricans where their ranges overlap. Our results indicate separation between the four species that range from the recent Pleistocene to late Pliocene (235,000-2.25million years ago). The Pacific A. achilles is the most divergent (and possibly ancestral) species with mtDNA dcorr≈0.04, whereas the other two Pacific species (A. japonicus and A. nigricans) are distinguishable only at a population or subspecies level (ΦST=0.6533, P<0.001). Little population structure was observed within species, with evidence of recent population expansion across all four geographic ranges. We detected sharing of mtDNA haplotypes between species and extensive hybridization based on microsatellites, consistent with later generation hybrids but also the effects of allele homoplasy. Despite extensive introgression, 98% of specimens had concordance between mtDNA lineage and

  12. Surgeons and suture zones: Hybridization among four surgeonfish species in the Indo-Pacific with variable evolutionary outcomes

    KAUST Repository

    DiBattista, Joseph

    2016-04-30

    Closely related species can provide valuable insights into evolutionary processes through comparison of their ecology, geographic distribution and the history recorded in their genomes. In the Indo-Pacific, many reef fishes are divided into sister species that come into secondary contact at biogeographic borders, most prominently where Indian Ocean and Pacific Ocean faunas meet. It is unclear whether hybridization in this contact zone represents incomplete speciation, secondary contact, an evolutionary dead-end (for hybrids) or some combination of the above. To address these issues, we conducted comprehensive surveys of two widely-distributed surgeonfish species, Acanthurus leucosternon (N = 141) and A. nigricans (N = 412), with mtDNA cytochrome b sequences and ten microsatellite loci. These surgeonfishes are found primarily in the Indian and Pacific Oceans, respectively, but overlap at the Christmas and Cocos-Keeling Islands hybrid zone in the eastern Indian Ocean. We also sampled the two other Pacific members of this species complex, A. achilles (N = 54) and A. japonicus (N = 49), which are known to hybridize with A. nigricans where their ranges overlap. Our results indicate separation between the four species that range from the recent Pleistocene to late Pliocene (235,000 to 2.25 million years ago). The Pacific A. achilles is the most divergent (and possibly ancestral) species with mtDNA dcorr ≈ 0.04, whereas the other two Pacific species (A. japonicus and A. nigricans) are distinguishable only at a population or subspecies level (ΦST = 0.6533, P < 0.001). Little population structure was observed within species, with evidence of recent population expansion across all four geographic ranges. We detected sharing of mtDNA haplotypes between species and extensive hybridization based on microsatellites, consistent with later generation hybrids but also the effects of allele homoplasy. Despite extensive introgression, 98% of specimens had concordance between mt

  13. Tropical Pacific Sea Surface Temperature Anomalies, El Niño, and Equatorial Westerly Wind Events*.

    Science.gov (United States)

    Vecchi, Gabriel A.; Harrison, D. E.

    2000-06-01

    The authors examine global statistical relationships between westerly wind events (WWEs) and sea surface temperature anomaly (SSTA) variability, using a compositing technique for the period 1986-98. The authors describe the extent to which equatorial WWEs are associated with central and eastern equatorial Pacific waveguide warming and with local SSTA changes under the WWE. Their goal is to quantify the extent to which equatorial WWEs are fundamental to the onset and maintenance of warm El Niño-Southern Oscillation conditions. In order to understand the effect of WWEs on SSTA evolution, they begin by examining how SSTA changes in the absence of equatorial WWEs. They find that SSTA tends toward mean climate values in the absence of equatorial WWEs, whether the eastern equatorial Pacific has close to normal SSTA or warmer than normal SSTA.The two equatorial WWE types whose main surface wind anomalies are west of the date line are associated with weak local surface cooling. The equatorial WWE type that has equatorial westerly wind anomalies east of the date line is associated with weak warming under those anomalies, when the eastern equatorial Pacific SSTA is close to normal.When the tropical Pacific has near-normal eastern equatorial Pacific SST, each of the equatorial WWE types is followed by substantial equatorial waveguide warming in the central and eastern Pacific (composite warming as large as 1.0°C); also more than 50% of the large-amplitude WWEs were followed by Niño-3 SSTA warming in excess of 0.5°C. These changes are of similar amplitude and spatial structure as those seen in the onset of El Niño and are consistent with the predicted oceanic response to WWE forcing. When the eastern equatorial Pacific is initially warmer than usual, the two westernmost equatorial WWE types are associated with the maintenance of warm El Niño eastern and central Pacific SSTA; these warm anomalies tend to disappear in the absence of those WWE types. WWEs, or some mechanism

  14. Quota Prices - Analysis and Reporting on Pacific Groundfish IFQ Quota Market

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The transfer of quota pounds and quota shares between participants in the Pacific Groundfish IFQ plays a critical role in facilitating fuller and more efficient...

  15. Plutonium and {sup 137}Cs in surface water of the South Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, K.; Komura, K. [Meteorological Research Institute, Nagamine 1-1, Tsukuba, Ibaraki 305-0052 (Japan); Low Level Radioactivity Laboratory, Kanazawa University, Wake, Nomi, Ishikawa 923-1224 (Japan); Aoyama, M. [Meteorological Research Institute, Nagamine 1-1, Tsukuba, Ibaraki 305-0052 (Japan); Fukasawa, M. [Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15, Natsushima, Yokosuka 237-0061 (Japan); Kim, C.S. [Korea Institute of Nuclear Safety, Daeduk-Danji Daejeon 305-336 (Korea); Povinec, P.P. [Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynska dolina F1, SK-842 48, Bratislava (Slovakia); Sanchez-Cabeza, J.A. [Marine Environment Laboratories, International Atomic Energy Agency, 4 Quai Antoine 1er, MC98000 (Monaco)

    2007-08-01

    The present plutonium and {sup 137}Cs concentrations in South Pacific Ocean surface waters were determined. The water samples were collected in the South Pacific mid-latitude region (32.5 S) during the BEAGLE expedition conducted in 2003-04 by JAMSTEC. {sup 239,240}Pu concentrations in surface seawater of the South Pacific were in the range of 0.5 to 4.1 mBq m{sup -3}, whereas {sup 137}Cs concentrations ranged from 0.07 to 1.7 Bq m{sup -3}. The observed {sup 239,240}Pu and {sup 137}Cs concentrations in the South Pacific were almost of the same level as those in the North Pacific subtropical gyre. The surface {sup 239,240}Pu in the South Pacific subtropical gyre showed larger spatial variations than {sup 137}Cs, as it may be affected by physical and biogeochemical processes. The {sup 239,240}Pu/{sup 137}Cs activity ratios, which reflect biogeochemical processes in seawater, were generally smaller than that observed in global fallout, except for the most eastern station. The {sup 239,240}Pu/{sup 137}Cs ratios in the South Pacific tend to be higher than that in the North Pacific. The relationships between anthropogenic radionuclides and oceanographic parameters such as salinity and nutrients were examined. The {sup 137}Cs concentrations in the western South Pacific (the Tasman Sea) and the eastern South Pacific were negatively correlated with the phosphate concentration, whereas there is no correlation between the {sup 137}Cs and nutrients concentrations in the South Pacific subtropical gyre. The mutual relationships between anthropogenic radionuclides and oceanographic parameters are important for better understanding of transport processes of anthropogenic radionuclides and their fate in the South Pacific. (author)

  16. Share your Sweets

    DEFF Research Database (Denmark)

    Byrnit, Jill; Høgh-Olesen, Henrik; Makransky, Guido

    2015-01-01

    as sharing in which group members were allowed to co-feed or remove food from the stock of the food possessor, and the introduction of high-value food resulted in more sharing, not less. Food sharing behavior differed between species in that chimpanzees displayed significantly more begging behavior than......All over the world, humans (Homo sapiens) display resource-sharing behavior, and common patterns of sharing seem to exist across cultures. Humans are not the only primates to share, and observations from the wild have long documented food sharing behavior in our closest phylogenetic relatives......, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). However, few controlled studies have been made where groups of Pan are introduced to food items that may be shared or monopolized by a first food possessor, and very few studies have examined what happens to these sharing patterns if the food...

  17. PRELIMINARY RESEARCH OF THE PACIFIC-INDIAN OCEAN SSTA MODE AND DEFINITION OF ITS INDEX

    Institute of Scientific and Technical Information of China (English)

    CHEN Lin-ling; JU Jian-hua; LI Chong-yin

    2005-01-01

    Applying the empirical orthogonal function (EOF) analysis to the sea surface temperature (SST) field of the tropical Pacific and Indian Oceans for determination of the first eigenvector field, the current work reveals that there are significant zonal gradients of SST in all seasons of the year in the northwestern and eastern Indian Ocean and equatorial central and eastern Pacific and western Pacific. It is also found that the variance contribution rates of the first EOF mode of every season is more than 33%. This shows that this kind of spatial distribution of the SST is stable. This pattern is named Pacific-Indian Oceans SSTA mode. Through careful analysis and comparison, an index of the mode was defined.

  18. On the Impact of Local Feedbacks in the Central Pacific on the ENSO Cycle.

    Science.gov (United States)

    Burgers, Gerrit; van Oldenborgh, Geert Jan

    2003-07-01

    While sea surface temperature (SST) anomalies in the eastern equatorial Pacific are dominated by the thermocline feedback, in the central equatorial Pacific local wind effects, such as zonal advection, are important as well. El Niño-Southern Oscillation (ENSO) simulations with a linear model improve markedly if these effects are included as a local wind stress feedback on SST. An atmosphere model that reacts both to eastern and central Pacific SST anomalies is needed for producing a realistic ENSO cycle.First, simulations are studied of a linear 1.5-layer reduced-gravity ocean model and a linear SST anomaly equation, forced by observed monthly wind stress. If only the thermocline feedback is present in the SST equation, SST can be simulated well in the eastern Pacific, but, contrary to observations, central Pacific SST is out of phase with the eastern Pacific. If a wind stress feedback is added in the SST equation, as a term proportional to the zonal wind stress, correlations between observed and simulated SST are above 0.8 in both the central and eastern Pacific, and the correlation between the Niño-3 (5°S-5°N, 90°-150°W) and Niño-4 (5°S-5°N, 150°W-160°E) indexes is close to the observed value of 0.75.Next, a statistical atmosphere is added to the ocean module that is based on a regression of observed wind stress to the observed Niño-3 and Niño-4 indexes. The coupled system is driven by noise that is inferred from the residues of the fit and has a red component. The observed Niño-3-Niño-4 index correlation can be reproduced only with a wind stress feedback in the central Pacific. Also, the level of SST variability rises and the ENSO period increases to more realistic values.The interplay between the local wind stress and the thermocline feedbacks, therefore, is an important factor in the structure of ENSO in the coupled linear model. In the eastern Pacific, the thermocline feedback dominates SST anomalies; in the central Pacific, the local wind

  19. Cloud Structure Anomalies Over the Tropical Pacific During the 1997/98 El Nino

    Science.gov (United States)

    Cess, Robert D.; Zhang, Minghua; Wang, Pi-Huan; Wielicki, Bruce A.

    2001-01-01

    Satellite measurements of both cloud vertical structure and cloud-radiative forcing have been used to show that during the strong 1997/98 El Nino there was a substantial change in cloud vertical structure over the tropical Pacific Ocean. Relative to normal years, cloud altitudes were lower in the western portion of the Pacific and higher in the eastern portion. The reason for these redistributions was a collapse of the Walker circulation and enhanced large-scale upward motion over the eastern Pacific, both caused by the lack of a zonal sea surface temperature gradient during El Nino. It is proposed that these cloud structure changes, which significantly impact satellite measurements of the tropical Pacific's radiation budget, would serve as one useful means of testing cloud-climate interactions in climate models.

  20. 50 CFR 300.25 - Eastern Pacific fisheries management.

    Science.gov (United States)

    2010-10-01

    ... 182 metric tons carrying capacity) using purse seine gear must be retained on board and landed, except... carrying capacity) may not be used to fish with purse seine gear in the Convention Area from 0000 hours on..., except that a vessel of class size 4 (182 to 272 metric tons carrying capacity) may make one fishing...

  1. ORGANOCHLORINE CONTAMINANTS IN SEA TURTLES FROM THE EASTERN PACIFIC

    Science.gov (United States)

    We measured organochlorine residues in three species of sea turtles from the Baja California peninsula, Mexico. Seventeen of 21 organochlorine pesticides analyzed were detected, with heptachlor epoxide and y-hexachlorocyclohexane the most prevalent in 14 (40%) and 11 (31%) of th...

  2. The Changing Eastern Winds: Dispersal in the Asia Pacific

    Science.gov (United States)

    2015-06-01

    refugees fleeing from violence in China to safety in Korea. His family later escaped Japanese and Russian forces traversing the peninsula by foot to its...end of the Century of Humiliation. As a result of this experience , China perceives the actions of foreign powers as part of a historical pattern of...freely, debauching the imperial concubines and sleeping in the Emperor’s bed.”26 Prime Minister Zhou controls the empire in all but name with Emperor

  3. The Changing Eastern Winds: Dispersal in the Asia-Pacific

    Science.gov (United States)

    2015-06-01

    refugees fleeing from violence in China to safety in Korea. His family later escaped Japanese and Russian forces traversing the peninsula by foot to its...end of the Century of Humiliation. As a result of this experience , China perceives the actions of foreign powers as part of a historical pattern of...freely, debauching the imperial concubines and sleeping in the Emperor’s bed.”26 Prime Minister Zhou controls the empire in all but name with Emperor

  4. Linguistic Diversity in the Pacific.

    Science.gov (United States)

    Crowley, Terry

    1999-01-01

    Reviews Peter Muhlhausler's book "Linguistic Ecology: Language Change and Linguistic Imperialism in the Pacific Region." Discusses the linguistic diversity of the Pacific, the linguistic impact of colonialism in the Pacific, and the role of linguists in the evolving linguistic situation in the Pacific. (Author/VWL)

  5. Interannual variability of western North Pacific SST anomalies and its impact on North Pacific and North America

    Science.gov (United States)

    Park, Jae-Heung; An, Soon-Il; Kug, Jong-Seong

    2017-02-01

    In this study, the interannual variability of sea surface temperature (SST) and its atmospheric teleconnection over the western North Pacific (WNP) toward the North Pacific/North America during boreal winter are investigated. First, we defined the WNP mode as the first empirical orthogonal function (EOF) mode of SST anomalies over the WNP region (100-165°E, 0-35°N), of which the principle component time-series are significantly correlated with several well-known climate modes such as the warm pool mode which is the second EOF mode of the tropical to North Pacific SST anomalies, North Pacific oscillation (NPO), North Pacific gyre oscillation (NPGO), and central Pacific (CP)-El Niño at 95% confidence level, but not correlated with the eastern Pacific (EP)-El Niño. The warm phase of the WNP mode (sea surface warming) is initiated by anomalous southerly winds through reduction of wind speed with the background of northerly mean winds over the WNP during boreal winter, i.e., reduced evaporative cooling. Meanwhile, the atmospheric response to the SST warming pattern and its diabatic heating further enhance the southerly wind anomaly, referred to the wind-evaporation-SST (WES) feedback. Thus, the WNP mode is developed and maintained through winter until spring, when the northerly mean wind disappears. Furthermore, it is also known that anomalous upper-level divergence associated with WNP mode leads to the NPO-like structure over the North Pacific and the east-west pressure contrast pattern over the North America through Rossby wave propagation, impacting the climate over the North Pacific and North America.

  6. Delta Oxygen-18 and SEA SURFACE TEMPERATURE collected from KNORR in Equatorial Pacific Ocean from 0862-01-01 to 2009-01-01 (NCEI Accession 0142201)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tropical Pacific Ocean dynamics during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) are poorly characterized due to lack of evidence from the eastern...

  7. Primer informe del género Gambierdiscus (Dinophyceae y otros dinoflagelados bentónicos en el Parque Nacional Isla del Coco, Costa Rica, Pacífico Tropical Oriental First report of the genus Gambierdiscus (Dinophyceae and other benthic dinoflagellates from Isla del Coco National Park, Costa Rica, Eastern Tropical Pacific

    Directory of Open Access Journals (Sweden)

    Maribelle Vargas-Montero

    2012-11-01

    conocer la incidencia de dinoflagelados bentónicos implicados en ciguatera para el Pacífico Tropical Oriental.The Eastern Tropical Pacific is a region reported as free of ciguatera poisoning that causes serious gastrointestinal, neural and cardiovascular problems, even death. But with this study we found a high incidence of benthic microalgae involved in ciguatera poisoning in Isla del Coco National Park (PNIC, from its name in Spanish, Costa Rica. Between 2006 and 2011, during expeditions to PNIC, 420 phytoplankton samples with the interest of finding benthic dinoflagellates involved in the ciguatera poisoning were collected and analyzed. Samples were taken with phytoplankton nets, towed vertically and horizontally or carried by diving, between 5 to 30 m depth, over reef areas, and by direct extraction from benthic macroalgae. We found the dinoflagellates Gambierdiscus spp., Coolia tropicalis, Coolia cf. areolota, Prorocentrum concavum, Prorocentrum compressum, Amphidinium carterae and Ostreopsis siamensis. The quantity of dinoflagellates by macroalgae weight was high, mainly for Gambierdiscus. Ostreopsis and Prorocentrum, the most widely distributed genera throughout the collection sites. Gambierdiscus is a ciguatera producing genus. Two different sizes of Gambierdiscus were found, and comparing our samples with other studies, we conclude that they are different to any previously reported. They possibly represent two new species. Coco Island is an oceanic island and because of its protection status, it is an ideal site for studying the evolution of marine phytoplankton. Also, long-term monitoring is important due to the variety of potentially toxic dinoflagellates living in this marine ecosystem. This is the first study to report benthic dinoflagellates implicated in ciguatera poisoning in other areas of the Eastern Tropical Pacific.

  8. Urban sharing culture

    DEFF Research Database (Denmark)

    Fjalland, Emmy Laura Perez

    In urban areas sharing cultures, services and economies are rising. People share, rent and recycle their homes, cars, bikes, rides, tools, cloths, working space, knowhow and so on. The sharing culture can be understood as mobilities (Kesselring and Vogl 2013) of goods, values and ideas reshaping...... our cities. The sharing economy has the power to democratise access the urban space, resources and raw materials (Steen Nielsen 2008; Harvey 2000); it holds the ability to change the current dominant understandings and structures of economy and growth (Steen Nielsen 2008); solve emerging environmental...... and trust. (Thomsen 2013; Bauman 2000; Beck 1992; Giddens 1991). The sharing economy is currently hyper trendy but before claiming capitalism as dead we need to understand the basics of the sharing economies and cultures asking who can share and what will we share. Furthermore it is crucial to study what...

  9. South Asian High and Asian-Pacific-American Climate Teleconnection

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Growing evidence indicates that the Asian monsoon plays an important role in affecting the weather and climate outside of Asia. However, this active role of the monsoon has not been demonstrated as thoroughly as has the variability of the monsoon caused by various impacting factors such as sea surface temperature and land surface. This study investigates the relationship between the Asian monsoon and the climate anomalies in the Asian-Pacific-American (APA) sector. A hypothesis is tested that the variability of the upper-tropospheric South Asian high (SAH), which is closely associated with the overall heating of the large-scale Asian monsoon, is linked to changes in the subtropical western Pacific high (SWPH), the midPacific trough, and the Mexican high. The changes in these circulation systems cause variability in surface temperature and precipitation in the APA region. A stronger SAH is accompanied by a stronger and more extensive SWPH. The enlargement of the SWPH weakens the mid-Pacific trough. As a result, the southern portion of the Mexican high becomes stronger. These changes are associated with changes in atmospheric teleconnections, precipitation, and surface temperature throughout the APA region. When the SAH is stronger, precipitation increases in southern Asia, decreases over the Pacific Ocean, and increases over the Central America. Precipitation also increases over Australia and central Africa and decreases in the Mediterranean region. While the signals in surface temperature are weak over the tropical land portion,they are apparent in the mid latitudes and over the eastern Pacific Ocean.

  10. Satisfaction and 'comparison sharing'

    DEFF Research Database (Denmark)

    Amilon, Anna

    2009-01-01

    the probability of satisfaction. Results show that comparison sharing impacts satisfaction for women, and that those women who share more equally than their peers are more likely to be satisfied, whereas comparison sharing has no influence on satisfaction for men. Also, parents are less likely to be satisfied...

  11. Multiproxy Reconstruction of Tropical Pacific Holocene Mean State Variability

    Science.gov (United States)

    Arbuszewski, J. A.; Oppo, D.; Huang, K. F.; Galy, V.; Dubois, N.; Mohtadi, M.; Herbert, T.; Rosenthal, Y.; Linsley, B. K.; Lynch-Stieglitz, J.; Koutavas, A.; Rustic, G. T.

    2014-12-01

    The El Niño-Southern Oscillation (ENSO) is the most prominent mode of tropical Pacific climate variability, significantly impacting both regional and global climate. In the past, the mean state of the Pacific Ocean has differed from today as evidenced by variability in the zonal water column structure. Recent paleoproxy based studies of tropical Pacific hydrology and surface temperature variability have hypothesized that observed climatological changes over the Holocene are directly linked to ENSO and/or mean state variability, complementing studies that dynamically relate centennial scale ENSO variability to mean state changes. These studies have suggested that mid Holocene ENSO variability was low and the mean state was more "La Niña" like. In the late Holocene, data have been interpreted as indicating an increase in ENSO variability with a more moderate mean state. Here, we test the hypothesis that observed climatological changes in the eastern tropical Pacific are related to mean state or ENSO variability during the Holocene. We focus our study on three sediment core locations from the equatorial Pacific: the Indo-Pacific Warm Pool (BJ803-119 GGC, 117MC), the Line Islands in the central Pacific (ML1208-18GC) and the Galapagos Islands in the Eastern Cold Tongue (KNR195-5 43 GGC, 42MC). These sites lie in regions poised to provide evidence of basin-wide equatorial water column structure changes in response to mean state and/or long-term ENSO variability. We use a multiproxy approach with data from both organic (sterol abundances) and inorganic proxies (Mg/Ca and δ18O of 4 planktonic foraminiferal species, % G. bulloides) to reconstruct zonal tropical Pacific (sub)surface temperature and stratification gradients over the Holocene. This approach enables us to combine the strengths of each individual proxy to derive more robust records. To put our data in the context of the broader Pacific and Indo-Pacific regions, we compare our new data to published records.

  12. Cooperation Over The Pacific

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Recently,there has been a media blitz both in the United States and beyond about the nation's "return to the Pacific" and the advent of an "American Pacific Century."Though the United States has never left the region-it has had a presence in the Asia-Pacific for more than 200 years-the notion of a U.S "return" to the region is prevalent.It was U.S.Secretary of State Hillary Clinton who told the world that "the United States is back in Southeast Asia." Over the coming decade,she said,one of the priorities of American statecraft will be "to lock in a substantially increased investment-diplomatic,economic,strategic,and otherwise-in the Asia-Pacific region."

  13. BSEE_Pacific_Pipelines

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains the locations of oil and gas pipelines in the Bureau of Safety and Environmental Enforcement Pacific OCS Region

  14. Subtropical Air-Sea Interaction and Development of Central Pacific El Ni(n)o

    Institute of Scientific and Technical Information of China (English)

    XIE Ruihuang; HUANG Fei; REN Hongli

    2013-01-01

    The standard deviation of the central Pacific sea surface temperature anomaly (SSTA) during the period from October to February shows that the central Pacific SSTA variation is primarily due to the occurrence of the Central Pacific El Ni(n)o (CP-El Ni(n)o)and has a connection with the subtropical air-sea interaction in the northeastern Pacific.After removing the influence of the Eastern Pacific El Ni(n)o,an S-EOF analysis is conducted and the leading mode shows a clear seasonal SSTA evolving from the subtropical northeastern Pacific to the tropical central Pacific with a quasi-biennial period.The initial subtropical SSTA is generated by the wind speed decrease and surface heat flux increase due to a north Pacific anomalous cyclone.Such subtropical SSTA can further influence the establishment of the SSTA in the tropical central Pacific via the wind-evaporation-SST (WES) feedback.After established,the central equatorial Pacific SSTA can be strengthened by the zonal advective feedback and thermocline feedback,and develop into CP-El Ni(n)o.However,as the thermocline feedback increases the SSTA cooling after the mature phase,the heat flux loss and the reversed zonal advective feedback can cause the phase transition of CP-El Ni(n)o.Along with the wind stress variability,the recharge (discharge) process occurs in the central (eastern) equatorial Pacific and such a process causes the phase consistency between the thermocline depth and SST anomalies,which presents a contrast to the original recharge/discharge theory.

  15. Conservation of native Pacific trout diversity in western North America

    Science.gov (United States)

    Penaluna, Brooke E.; Abadía-Cardoso, Alicia; Dunham, Jason; García de León, Francisco J; Gresswell, Robert E.; Luna, Arturo Ruiz; Taylor, Eric B.; Shepard, Bradley B.; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Bestgen, Kevin R.; Rogers, Kevin H.; Escalante, Marco A; Keeley, Ernest R; Temple, Gabriel; Williams, Jack E.; Matthews, Kathleen; Pierce, Ron; Mayden, Richard L.; Kovach, Ryan; Garza, John Carlos; Fausch, Kurt D.

    2016-01-01

    Pacific trout Oncorhynchus spp. in western North America are strongly valued in ecological, socioeconomic, and cultural views, and have been the subject of substantial research and conservation efforts. Despite this, the understanding of their evolutionary histories, overall diversity, and challenges to their conservation is incomplete. We review the state of knowledge on these important issues, focusing on Pacific trout in the genus Oncorhynchus. Although most research on salmonid fishes emphasizes Pacific salmon, we focus on Pacific trout because they share a common evolutionary history, and many taxa in western North America have not been formally described, particularly in the southern extent of their ranges. Research in recent decades has led to the revision of many hypotheses concerning the origin and diversification of Pacific trout throughout their range. Although there has been significant success at addressing past threats to Pacific trout, contemporary and future threats represented by nonnative species, land and water use activities, and climate change pose challenges and uncertainties. Ultimately, conservation of Pacific trout depends on how well these issues are understood and addressed, and on solutions that allow these species to coexist with a growing scope of human influences.

  16. Summer Asian-Pacific Oscillation and Its Relationship with Atmospheric Circulation and Monsoon Rainfall

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ping; CHEN Junming; XIAO Dong; NAN Sulan; ZOU Yan; ZHOU Botao

    2008-01-01

    Using the ERA-40 data and numerical simulations, this study investigated the teleconnection over the extratropical Asian-Pacific region and its relationship with the Asian monsoon rainfall and the climatological characteristics of tropical cyclones over the western North Pacific, and analyzed impacts of the Tibetan Plateau (TP) heating and Pacific sea surface temperature (SST) on the teleconnection. The Asian-Pacific oscillation (APO) is defined as a zonal seesaw of the tropospheric temperature in the midlatitudes of the Asian-Pacific region. When the troposphere is cooling in the midlatitudes of the Asian continent, it is warming in the midlatitudes of the central and eastern North Pacific; and vice versa. The APO also appears in the stratosphere, but with a reversed phase. Used as an index of the thermal contrast between Asia and the North Pacific, it provides a new way to explore interactions between the Asian and Pacific atmospheric circulations. The APO index exhibits the interannual and interdecadal variability. It shows a downward trend during 1958-2001, indicating a weakening of the thermal contrast, and shows a 5.5-yr oscillation period. The formation of the APO is associated with the zonal vertical circulation caused by a difference in the solar radiative heating between the Asian continent and the North Pacific. The numerical simulations further reveal that the summer TP heating enhances the local tropospheric temperature and upward motion, and then strengthens downward motion and decreases the tropospheric temperature over the central and eastern North Pacific. This leads to the formation of the APO. The Pacific decadal oscillation and El Nino/La Nina over the tropical eastern Pacific do not exert strong influences on the APO. When there is an anomaly in the summer APO, the South Asian high, the westerly jet over Eurasia, the tropical easterly jet over South Asia, and the subtropical high over the North Pacific change significantly, with anomalous Asian

  17. Role of observed Pacific trade wind trends in the recent hiatus and future projections

    Science.gov (United States)

    Maher, Nicola; England, Matthew; Gupta, Alex Sen; Spence, Paul

    2017-04-01

    Over the period 2001-2013 a slowdown (or 'hiatus') in global surface temperature has been observed. Recent studies have identified Pacific decadal variability as a major driver of hiatus and accelerated warming periods. Here we use an eddy-permitting global ocean model to investigate the role of the observed 1992-2011 trade wind intensification and associated atmospheric surface changes related with a strong negative phase of the Interdecadal Pacific Oscillation (IPO) in driving ocean circulation and heat content changes. We find a strengthening of the Pacific shallow overturning cells and Equatorial Undercurrent (EUC) in response to strengthened winds, which brings cooler water to the surface of the eastern Pacific and transports additional heat into the subsurface western Pacific. The intensified winds also increase the volume and heat transport of the Indonesian Throughflow, moving some of the additional heat from the western Pacific into the Indian Ocean. The net result is a warmer subsurface western Pacific, a cooler upper eastern Pacific and a warmer subsurface Indian Ocean, with an overall increase in Indo-Pacific heat content. Extended experiments with a symmetric reversal of the atmospheric state examine how the ocean would respond if the winds (and other associated atmospheric variables) were to revert to their initial state. We find a slowdown of the EUC and Pacific shallow overturning cells, resulting in a return to climatological SST conditions in the western and eastern Pacific. The ITF also slows toward its original strength. However, the temperature, heat content and ITF responses are not entirely symmetric due to an overall increase in the surface heat flux into the ocean associated with the cooler surface of the Pacific and irreversible heat transfer from the Pacific into the Indian Ocean via the ITF. There is also irreversible heat transport across the thermocline via diapycnal mixing, further contributing to this asymmetry. Consequently, after

  18. REGIONAL FEATURES OF LONG-TERM SST VARIATION IN THE WESTERN PACIFIC WARM POOL AREA

    Institute of Scientific and Technical Information of China (English)

    张启龙; 翁学传; 程明华

    2001-01-01

    The main features of SST interarmual and long-term variations in the Western Pacific Warm Pool area were studied by using regression analysis, running t-test and spectral analysis methods based on monthly mean SST data in the Pacific during 1950 - 1998. The results showed that the SST inter-annual and long-term variations in the Western Pacific Warm Pool area had evident regional features.There were significant differences in variation range, phase, period, occurrence time of abrupt variation between SST in the eastern area (east of 100°E) and SST in the western area (west of 100°E).

  19. The Eastern Partnership

    DEFF Research Database (Denmark)

    Nielsen, Kristian L.; Vilson, Maili

    2014-01-01

    When the EU launched the Eastern Partnership (EaP) in 2009, it did so with much rhetoric about projecting its soft power into Eastern Europe. Yet today, the EU's soft power project seems to have stalled, with developments in the region being less than favourable. This article argues that the EaP ...

  20. Eastern Europe's Silicon Rush

    Science.gov (United States)

    Woodard, Colin

    2007-01-01

    This article presents how the fast expansion of information technology industry in eastern Slovakia is putting a strain on its labor supply. Suddenly, computer-science graduates have become one of the former Eastern Bloc's greatest assets, attracting multinational technology companies hungry for skilled programmers, technicians, and engineers.…

  1. Leading from the Middle of the Organization: An Examination of Shared Leadership in Academic Libraries

    Science.gov (United States)

    Cawthorne, Jon E.

    2010-01-01

    Shared leadership theory recognizes leader influence throughout the organization, not just from the top down. This study explores how middle managers from 22 academic libraries in the Pacific West perceive their own agreement, participation and recognition of shared leadership. This survey and framework is the first to examine the extent shared…

  2. Resource Sharing, Interlibrary Loan and Orbis: How Did We Get Here and Where Are We Going?

    Science.gov (United States)

    Halgren, Joanne V.

    1998-01-01

    Describes the development of resource sharing through interlibrary loan among Orbis libraries, a consortium of institutions of higher education in the Northwest. Highlights include the Pacific Northwest Bibliographic Center (PNBC), Oregon Regional Union List of Serials (ORULS), shared electronic catalogs, OhioLINK, and OCLC interlibrary loan…

  3. Western Pacific hydroclimate linked to global climate variability over the past two millennia

    Science.gov (United States)

    Griffiths, Michael L.; Kimbrough, Alena K.; Gagan, Michael K.; Drysdale, Russell N.; Cole, Julia E.; Johnson, Kathleen R.; Zhao, Jian-Xin; Cook, Benjamin I.; Hellstrom, John C.; Hantoro, Wahyoe S.

    2016-06-01

    Interdecadal modes of tropical Pacific ocean-atmosphere circulation have a strong influence on global temperature, yet the extent to which these phenomena influence global climate on multicentury timescales is still poorly known. Here we present a 2,000-year, multiproxy reconstruction of western Pacific hydroclimate from two speleothem records for southeastern Indonesia. The composite record shows pronounced shifts in monsoon rainfall that are antiphased with precipitation records for East Asia and the central-eastern equatorial Pacific. These meridional and zonal patterns are best explained by a poleward expansion of the Australasian Intertropical Convergence Zone and weakening of the Pacific Walker circulation (PWC) between ~1000 and 1500 CE Conversely, an equatorward contraction of the Intertropical Convergence Zone and strengthened PWC occurred between ~1500 and 1900 CE. Our findings, together with climate model simulations, highlight the likelihood that century-scale variations in tropical Pacific climate modes can significantly modulate radiatively forced shifts in global temperature.

  4. Relationship between the tropical cyclone genesis over the Northwest Pacific and the sea surface temperature anomalies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using the tropical cyclone (TC) data derived from the Joint Typhoon Warning Center (JTWC) and the sea surface temperature data derived from the Joint Environmental Data Analysis Center (JEDAC) at the Scripps Institute of Oceanography from January 1955 to December 2000, we analyzed the relationship between the TC genesis over the Northwest Pacific (NWP) and the sea surface temperature anomalies (SSTA) over the Pacific basin. A long-term trend indicated that the highest frequency of monthly TC genesis appeared earlier and the annual genesis sum increased gradually during the last half century with some oscillations. No significant synchronous correlation was found between the NWP TC events and the SSTA over the Pacific basin, while the annual sum of TC genesis was closely related with the SSTA averaged from the first three months (January, February and March) of the year in the equatorial western and eastern Pacific and over mid-high latitudes of the North Pacific. The results implied that there are an interannual El Ni(n)o SSTA mode in the equatorial western and eastern Pacific and an interdecadal SSTA mode in the northern Pacific, which affected the TC genesis. A regression analysis between the first three-month SSTA and the annual TC sum based on two time scales was conducted. The correlation coefficient between simulated and observed TC sums reached a high value of 0.77.

  5. Predicting bycatch hotspots for endangered leatherback turtles on longlines in the Pacific Ocean.

    Science.gov (United States)

    Roe, John H; Morreale, Stephen J; Paladino, Frank V; Shillinger, George L; Benson, Scott R; Eckert, Scott A; Bailey, Helen; Tomillo, Pilar Santidrián; Bograd, Steven J; Eguchi, Tomoharu; Dutton, Peter H; Seminoff, Jeffrey A; Block, Barbara A; Spotila, James R

    2014-02-22

    Fisheries bycatch is a critical source of mortality for rapidly declining populations of leatherback turtles, Dermochelys coriacea. We integrated use-intensity distributions for 135 satellite-tracked adult turtles with longline fishing effort to estimate predicted bycatch risk over space and time in the Pacific Ocean. Areas of predicted bycatch risk did not overlap for eastern and western Pacific nesting populations, warranting their consideration as distinct management units with respect to fisheries bycatch. For western Pacific nesting populations, we identified several areas of high risk in the north and central Pacific, but greatest risk was adjacent to primary nesting beaches in tropical seas of Indo-Pacific islands, largely confined to several exclusive economic zones under the jurisdiction of national authorities. For eastern Pacific nesting populations, we identified moderate risk associated with migrations to nesting beaches, but the greatest risk was in the South Pacific Gyre, a broad pelagic zone outside national waters where management is currently lacking and may prove difficult to implement. Efforts should focus on these predicted hotspots to develop more targeted management approaches to alleviate leatherback bycatch.

  6. Simulation of low clouds in the Southeast Pacific by the NCEP GFS: sensitivity to vertical mixing

    Directory of Open Access Journals (Sweden)

    R. Sun

    2010-12-01

    Full Text Available The NCEP Global Forecast System (GFS model has an important systematic error shared by many other models: stratocumuli are missed over the subtropical eastern oceans. It is shown that this error can be alleviated in the GFS by introducing a consideration of the low-level inversion and making two modifications in the model's representation of vertical mixing. The modifications consist of (a the elimination of background vertical diffusion above the inversion and (b the incorporation of a stability parameter based on the cloud-top entrainment instability (CTEI criterion, which limits the strength of shallow convective mixing across the inversion. A control simulation and three experiments are performed in order to examine both the individual and combined effects of modifications on the generation of the stratocumulus clouds. Individually, both modifications result in enhanced cloudiness in the Southeast Pacific (SEP region, although the cloudiness is still low compared to the ISCCP climatology. If the modifications are applied together, however, the total cloudiness produced in the southeast Pacific has realistic values. This nonlinearity arises as the effects of both modifications reinforce each other in reducing the leakage of moisture across the inversion. Increased moisture trapped below the inversion than in the control run without modifications leads to an increase in cloud amount and cloud-top radiative cooling. Then a positive feedback due to enhanced turbulent mixing in the planetary boundary layer by cloud-top radiative cooling leads to and maintains the stratocumulus cover. Although the amount of total cloudiness obtained with both modifications has realistic values, the relative contributions of low, middle, and high layers tend to differ from the observations. These results demonstrate that it is possible to simulate realistic marine boundary clouds in large-scale models by implementing direct and physically based improvements in the

  7. Simulation of low clouds in the Southeast Pacific by the NCEP GFS: sensitivity to vertical mixing

    Directory of Open Access Journals (Sweden)

    R. Sun

    2010-08-01

    Full Text Available The NCEP Global Forecast System (GFS model has an important systematic error shared by many other models: stratocumuli are missed over the subtropical eastern oceans. It is shown that this error can be alleviated in the GFS by introducing a consideration of the low-level inversion and making two modifications in the model's representation of vertical mixing. The modifications consist of (a the elimination of background vertical diffusion above the inversion and (b the incorporation of a stability parameter based on the cloud-top entrainment instability (CTEI criterion, which limits the strength of shallow convective mixing across the inversion. A control simulation and three experiments are performed in order to examine both the individual and combined effects of modifications on the generation of the stratocumulus clouds. Individually, both modifications result in enhanced cloudiness in the Southeast Pacific (SEP region, although the cloudiness is still low compared to the ISCCP climatology. If the modifications are applied together, however, the total cloudiness produced in the southeast Pacific has realistic values. This nonlinearity arises as the effects of both modifications reinforce each other in reducing the leakage of moisture across the inversion. Increased moisture trapped below the inversion than in the control run without modifications leads to an increase in cloud amount and cloud-top radiative cooling. Then a positive feedback due to enhanced turbulent mixing in the planetary boundary layer by cloud-top radiative cooling leads to and maintains the stratocumulus cover. Although the amount of total cloudiness obtained with both modifications has realistic values, the relative contributions of low, middle, and high layers tend to differ from the observations. These results demonstrate that it is possible to simulate realistic marine boundary clouds in large-scale models by implementing direct and physically based improvements in the

  8. Simulation of low clouds in the Southeast Pacific by the NCEP GFS: sensitivity to vertical mixing

    Science.gov (United States)

    Sun, R.; Moorthi, S.; Xiao, H.; Mechoso, C. R.

    2010-12-01

    The NCEP Global Forecast System (GFS) model has an important systematic error shared by many other models: stratocumuli are missed over the subtropical eastern oceans. It is shown that this error can be alleviated in the GFS by introducing a consideration of the low-level inversion and making two modifications in the model's representation of vertical mixing. The modifications consist of (a) the elimination of background vertical diffusion above the inversion and (b) the incorporation of a stability parameter based on the cloud-top entrainment instability (CTEI) criterion, which limits the strength of shallow convective mixing across the inversion. A control simulation and three experiments are performed in order to examine both the individual and combined effects of modifications on the generation of the stratocumulus clouds. Individually, both modifications result in enhanced cloudiness in the Southeast Pacific (SEP) region, although the cloudiness is still low compared to the ISCCP climatology. If the modifications are applied together, however, the total cloudiness produced in the southeast Pacific has realistic values. This nonlinearity arises as the effects of both modifications reinforce each other in reducing the leakage of moisture across the inversion. Increased moisture trapped below the inversion than in the control run without modifications leads to an increase in cloud amount and cloud-top radiative cooling. Then a positive feedback due to enhanced turbulent mixing in the planetary boundary layer by cloud-top radiative cooling leads to and maintains the stratocumulus cover. Although the amount of total cloudiness obtained with both modifications has realistic values, the relative contributions of low, middle, and high layers tend to differ from the observations. These results demonstrate that it is possible to simulate realistic marine boundary clouds in large-scale models by implementing direct and physically based improvements in the model

  9. 中东太平洋公海金枪鱼延绳钓误捕海龟的观察和分析%Observation and analysis of sea turtles mortality longline fishing in high seas of Central and Eastern Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    戴小杰; 李延; 许柳雄; 朱江峰

    2009-01-01

    根据2006年2-11月科学观察员对热带东太平洋公海海域(05°N~10°S,134°W~173°W)金枪鱼延绳钓渔业的调查,期间共投钩223次(天),误捕到绿海龟、蠵龟、丽龟、玳瑁和棱皮龟5种共22尾,死亡海龟13尾.从海龟误捕率看,平均每次尾数为0.098 65.平均每千钩尾数0.037 40.从海龟的钩获部位看,喙(嘴)上钩占41.0%,躯干部位上钩占13.6%,喉部上钩占13.6%,前肢上钩占18.2%,主绳缠绕被捕获占13.6%.海龟的误捕区域位于04°S以北海域,几乎可全年捕获.此外分析了不同钩位误捕海龟的数量,探讨了影响误捕率和死亡率的因素,提出保护对策.%Based on the data by scientific observer survey in the tropical Central and Eastern Pacific Ocean (05°N -10°S,134° W -173°W) by the tuna longline fishery targeting bigeye tuna during Feb.-Nov. , 2006, with the total 223 sets, 22 sea turtle bycatch were observed and analysed. The incidental sea turtles were classified as 5 species, namely green sea turtles (Chelonia mydas),loggerhead (Caretta caretta),Oliver ridley turtle (Lepidochelys olivacea), hawksbill turtle ( Eretmochelys imbricata) and leatherback turtle (Dermochelys coriacea) with total 22 individuals. There were 13 sea turtles mortality after capture. The incidental catch rate is 0. 09865 per set and 0. 374 0 per thousand hooks. The interaction between fishing gear and sea turtles showed that sea turtle body were hooked with mouth accounting for 41. 0% , external parts 13.6% , swallowed 13.6% .foreleg 18.2% and mainline entangement 13.6%. Most sea turtle bycatch occurred north of 04°S and almost all the year round. Analysis was also made to identify the specific hook number for interaction with sea turtles. Discussion was made on factors for affecting catch rate and mortality. Measures were suggested on conservation and by-catch mitigation for sea turtles.

  10. 78 FR 64200 - Innovative Spectrum Sharing Technology Day Event

    Science.gov (United States)

    2013-10-28

    ... National Telecommunications and Information Administration Innovative Spectrum Sharing Technology Day Event.... The event will be open to the public and will provide policy-makers, researchers, industry..., from 10 a.m. to 3 p.m. Eastern Standard Time. ADDRESSES: The event will take place at the U.S...

  11. The Sharing Economy

    DEFF Research Database (Denmark)

    Avital, Michel; Carroll, John M.; Hjalmarsson, Anders

    2015-01-01

    The sharing economy is spreading rapidly worldwide in a number of industries and markets. The disruptive nature of this phenomenon has drawn mixed responses ranging from active conflict to adoption and assimilation. Yet, in spite of the growing attention to the sharing economy, we still do not know...... much about it. With the abundant enthusiasm about the benefits that the sharing economy can unleash and the weekly reminders about its dark side, further examination is required to determine the potential of the sharing economy while mitigating its undesirable side effects. The panel will join...... the ongoing debate about the sharing economy and contribute to the discourse with insights about how digital technologies are critical in shaping this turbulent ecosystem. Furthermore, we will define an agenda for future research on the sharing economy as it becomes part of the mainstream society as well...

  12. Mercury in Pacific bluefin tuna (Thunnus orientalis):bioaccumulation and trans-Pacific Ocean migration

    Science.gov (United States)

    Colman, John A.; Nogueira, Jacob I.; Pancorbo, Oscar C.; Batdorf, Carol A.; Block, Barbara A.

    2015-01-01

    Pacific bluefin tuna (Thunnus orientalis) have the largest home range of any tuna species and are well known for the capacity to make transoceanic migrations. We report the measurement of mercury (Hg) concentrations in wild Pacific bluefin tuna (PBFT), the first reported with known size-of-fish and capture location. The results indicate juvenile PBFT that are recently arrived in the California Current from the western Pacific Ocean have significantly higher Hg concentrations in white muscle (0.51 ug/g wet mass, wm) than PBFT of longer California Current residency (0.41 ug/g wm). These new arrivals are also higher in Hg concentration than PBFT in farm pens (0.43 ug/g wm) that were captured on arrival in the California Current and raised in pens on locally derived feed. Analysis by direct Hg analyzer and attention to Hg by tissue type and location on the fish allowed precise comparisons of mercury among wild and captive fish populations. Analysis of migration and nearshore residency, determined through extensive archival tagging, bioaccumulation models, trophic investigations, and potential coastal sources of methylmercury, indicates Hg bioaccumulation is likely greater for PBFT juvenile habitats in the western Pacific Ocean (East China Sea, Yellow Sea) than in the eastern Pacific Ocean (California Current). Differential bioaccumulation may be a trophic effect or reflect methylmercury availability, with potential sources for coastal China (large hypoxic continental shelf receiving discharge of three large rivers, and island-arc volcanism) different from those for coastal Baja California (small continental shelf, no large rivers, spreading-center volcanism).

  13. Factors Impacting Knowledge Sharing

    DEFF Research Database (Denmark)

    Schulzmann, David; Slepniov, Dmitrij

    The purpose of this paper is to examine various factors affecting knowledge sharing at the R&D center of a Western MNE in China. The paper employs qualitative methodology and is based on the action research and case study research techniques. The findings of the paper advance our understanding...... about factors that affect knowledge sharing. The main emphasis is given to the discussion on how to improve knowledge sharing in global R&D organizations....

  14. Facilitating Knowledge Sharing

    DEFF Research Database (Denmark)

    Holdt Christensen, Peter

    Abstract This paper argues that knowledge sharing can be conceptualized as different situations of exchange in which individuals relate to each other in different ways, involving different rules, norms and traditions of reciprocity regulating the exchange. The main challenge for facilitating...... and the intermediaries regulating the exchange, and facilitating knowledge sharing should therefore be viewed as a continuum of practices under the influence of opportunistic behaviour, obedience or organizational citizenship behaviour. Keywords: Knowledge sharing, motivation, organizational settings, situations...

  15. Facilitating Knowledge Sharing

    OpenAIRE

    Holdt Christensen, Peter

    2005-01-01

    Abstract This paper argues that knowledge sharing can be conceptualized as different situations of exchange in which individuals relate to each other in different ways, involving different rules, norms and traditions of reciprocity regulating the exchange. The main challenge for facilitating knowledge sharing is to ensure that the exchange is seen as equitable for the parties involved, and by viewing the problems of knowledge sharing as motivational problems situated in different organization...

  16. Eastern China Geological and Mining Organization for Nonferrous Metals Becomes the Controlling Shareholder of the Boka Gold Deposit with 400-ton Future Reserves

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The Eastern China Geological and Mining Or- ganization for Nonferrous Metals recently ac- quired all of the former foreign-enterprise- owned shares,becoming the controlling share- holder of the deposit.Crowned as a "world-

  17. Stroke and Native Hawaiians/Pacific Islanders

    Science.gov (United States)

    ... Population Profiles > Native Hawaiian/Other Pacific Islander > Stroke Stroke and Native Hawaiians/Pacific Islanders Native Hawaiians/Pacific ... non-Hispanic white adults to die from a stroke in 2010. In general, Native Hawaiian/Pacific Islander ...

  18. A Data Sharing Story

    Directory of Open Access Journals (Sweden)

    Mercè Crosas

    2012-01-01

    Full Text Available From the early days of modern science through this century of Big Data, data sharing has enabled some of the greatest advances in science. In the digital age, technology can facilitate more effective and efficient data sharing and preservation practices, and provide incentives for making data easily accessible among researchers. At the Institute for Quantitative Social Science at Harvard University, we have developed an open-source software to share, cite, preserve, discover and analyze data, named the Dataverse Network. We share here the project’s motivation, its growth and successes, and likely evolution.

  19. Phenomenology of experiential sharing

    DEFF Research Database (Denmark)

    León, Felipe; Zahavi, Dan

    2016-01-01

    The chapter explores the topic of experiential sharing by drawing on the early contributions of the phenomenologists Alfred Schutz and Gerda Walther. It is argued that both Schutz and Walther support, from complementary perspectives, an approach to experiential sharing that has tended...... to be overlooked in current debates. This approach highlights specific experiential interrelations taking place among individuals who are jointly engaged and located in a common environment, and situates this type of sharing within a broader and richer spectrum of sharing phe- nomena. Whereas Schutz’ route...

  20. Phenomenology of experiential sharing

    DEFF Research Database (Denmark)

    León, Felipe; Zahavi, Dan

    2016-01-01

    The chapter explores the topic of experiential sharing by drawing on the early contributions of the phenomenologists Alfred Schutz and Gerda Walther. It is argued that both Schutz and Walther support, from complementary perspectives, an approach to experiential sharing that has tended to be overl......The chapter explores the topic of experiential sharing by drawing on the early contributions of the phenomenologists Alfred Schutz and Gerda Walther. It is argued that both Schutz and Walther support, from complementary perspectives, an approach to experiential sharing that has tended...

  1. 77 FR 73969 - International Fisheries; Pacific Tuna Fisheries; Fishing Restrictions in the Eastern Pacific Ocean

    Science.gov (United States)

    2012-12-12

    .... The IATTC has maintained a scientific research and fishery monitoring program for many years, and.... Current IATTC membership includes: Belize, Canada, China, Chinese Taipei (Taiwan), Colombia, Costa Rica... bluefin tuna resource. Future conservation measures should be based in part on development of future...

  2. 76 FR 60790 - International Fisheries; Pacific Tuna Fisheries; Fishing Restrictions in the Eastern Pacific Ocean

    Science.gov (United States)

    2011-09-30

    .... meridian. The members of the IATTC are Belize, Canada, China, Chinese Taipei, Colombia, Costa Rica, Ecuador... weather forecasting, tsunami warnings, search and rescue efforts, and research of the marine environment... entangled fishing gear with as little damage to the data buoy as possible. If a scientific research program...

  3. 78 FR 33240 - International Fisheries; Pacific Tuna Fisheries; Fishing Restrictions in the Eastern Pacific Ocean

    Science.gov (United States)

    2013-06-04

    .... and 50 S. parallels, and the 150 W. meridian. The IATTC has maintained a scientific research and..., Canada, China, Chinese Taipei (Taiwan), Colombia, Costa Rica, Ecuador, El Salvador, the European Union...

  4. 76 FR 68332 - International Fisheries; Pacific Tuna Fisheries; Fishing Restrictions in the Eastern Pacific Ocean

    Science.gov (United States)

    2011-11-04

    ... loss of data critical to weather forecasting, tsunami warnings, search and rescue efforts, and research... does not apply if the fishing vessel is operating as part of a scientific research program that.... (e.g., American Samoa) or foreign (e.g., Ecuador, Mexico, Colombia, Costa Rica) ports. Skipjack and...

  5. Pacific Coastal Salmon Recovery Fund

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Congress established the Pacific Coastal Salmon Recovery Fund (PCSRF) to monitor the restoration and conservation of Pacific salmon and steelhead populations and...

  6. RELATIONSHIPS BETWEEN ZONAL WIND ANOMALIES IN HIGH AND LOW TROPOSPHERE AND ANNUAL FREQUENCY OF NW PACIFIC TROPICAL CYCLONES

    Institute of Scientific and Technical Information of China (English)

    GONG Zhen-song; HE Min

    2007-01-01

    Relationships between large-scale zonal wind anomalies and annual frequency of NW Pacific tropical cyclones and possible mechanisms are investigated with the methods of correlation and composition.It is indicated that when △ U200-△U850 >0 in the eastern tropical Pacific and △ U200- △U850 <0 in western tropical Pacific, the Walker cell is stronger in the Pacific tropical region and the annual frequency of NW Pacific tropical cyclone are above normal. In the years with zonal wind anomalies, the circulation of high and low troposphere and the vertical motions in the troposphere have significant characteristics. In the time scale of short-range climate prediction, zonal wind anomalies in high and low troposphere are useful as a preliminary signal of the annual frequency prediction of NW Pacific tropical cyclones.

  7. Albatross species demonstrate regional differences in North Pacific marine contamination.

    Science.gov (United States)

    Finkelstein, Myra; Keitt, Bradford S; Croll, Donald A; Tershy, Bernie; Jarman, Walter M; Rodriguez-Pastor, Sue; Anderson, David J; Sievert, Paul R; Smith, Donald R

    2006-04-01

    Recent concern about negative effects on human health from elevated organochlorine and mercury concentrations in marine foods has highlighted the need to understand temporal and spatial patterns of marine pollution. Seabirds, long-lived pelagic predators with wide foraging ranges, can be used as indicators of regional contaminant patterns across large temporal and spatial scales. Here we evaluate contaminant levels, carbon and nitrogen stable isotope ratios, and satellite telemetry data from two sympatrically breeding North Pacific albatross species to demonstrate that (1) organochlorine and mercury contaminant levels are significantly higher in the California Current compared to levels in the high-latitude North Pacific and (2) levels of organochlorine contaminants in the North Pacific are increasing over time. Black-footed Albatrosses (Phoebastria nigripes) had 370-460% higher organochlorine (polychlorinated biphenyls [PCBs], dichlorodiphenyltrichloroethanes [DDTs]) and mercury body burdens than a closely related species, the Laysan Albatross (P. immutabilis), primarily due to regional segregation of their North Pacific foraging areas. PCBs (the sum of the individual PCB congeners analyzed) and DDE concentrations in both albatross species were 130-360% higher than concentrations measured a decade ago. Our results demonstrate dramatically high and increasing contaminant concentrations in the eastern North Pacific Ocean, a finding relevant to other marine predators, including humans.

  8. Report on an analytical survey on the Pacific energy information; Taiheiyo energy joho bunseki chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    For the purpose of collecting and arranging energy information in the Asia and Pacific region, this survey has been conducted for many fiscal years. The Asia and Pacific region is classified into the Chinese area, the Southeast Asia area including Brunei, Indonesia, the Philippine, Singapore and Thailand, the East Asia area including Japan, Korea, Taiwan and Hong Kong, the North America area including the U.S. and Canada, and the Oceania area including Australia and New Zealand. As to the primary energy supplied from 1980 to 1993, China largely increased its share by 3.1%. The Southeast Asia also increased its share by 2.1%, and the East Asia by 2.5%. To the contrary, the North America area largely declined its share by 7.8%, but still has approximately 60% in the Asia and Pacific area. By kind of energy, coal increased the share while oil decreased. 16 figs., 7 tabs.

  9. Libraries, Archives, and Museums Helping Create Futures: Building on Culture, Knowledge, and Information through Collaboration and Resource Sharing. Selected Papers from PIALA 2010, Pacific Islands Association of Libraries, Archives, and Museums Annual Conference (20th, Weno, Chuuk State, Federated States of Micronesia, November 15-19, 2010)

    Science.gov (United States)

    Drake, Paul B., Ed.

    2012-01-01

    This publication follows the tradition of publishing selected papers from Pacific Islands Association of Libraries, Archives and Museums (PIALA) annual conferences. This 20th annual conference was held in Weno, Chuuk State, Federated States of Micronesia, November 15-19, 2010. The volume begins with a listing of the members of the PIALA 2010…

  10. The Sharing Economy

    DEFF Research Database (Denmark)

    Avital, Michel; Carroll, John M.; Hjalmarsson, Anders;

    2015-01-01

    The sharing economy is spreading rapidly worldwide in a number of industries and markets. The disruptive nature of this phenomenon has drawn mixed responses ranging from active conflict to adoption and assimilation. Yet, in spite of the growing attention to the sharing economy, we still do not kn...

  11. Limitations to sharing entanglement

    CERN Document Server

    Kim, Jeong San; Sanders, Barry C

    2011-01-01

    We discuss limitations to sharing entanglement known as monogamy of entanglement. Our pedagogical approach commences with simple examples of limited entanglement sharing for pure three-qubit states and progresses to the more general case of mixed-state monogamy relations with multiple qudits.

  12. 5G Spectrum Sharing

    OpenAIRE

    Nekovee, Maziar; Rudd, Richard

    2017-01-01

    In this paper an overview is given of the current status of 5G industry standards, spectrum allocation and use cases, followed by initial investigations of new opportunities for spectrum sharing in 5G using cognitive radio techniques, considering both licensed and unlicensed scenarios. A particular attention is given to sharing millimeter-wave frequencies, which are of prominent importance for 5G.

  13. Shared Parenting Dysfunction.

    Science.gov (United States)

    Turkat, Ira Daniel

    2002-01-01

    Joint custody of children is the most prevalent court ordered arrangement for families of divorce. A growing body of literature indicates that many parents engage in behaviors that are incompatible with shared parenting. This article provides specific criteria for a definition of the Shared Parenting Dysfunction. Clinical aspects of the phenomenon…

  14. Palaeotsunamis in the Pacific Islands

    Science.gov (United States)

    Goff, J.; Chague-Goff, C.; Dominey-Howes, D.; McAdoo, B.; Cronin, S.; Bonte-Grapetin, Michael; Nichol, S.; Horrocks, M.; Cisternas, M.; Lamarche, G.; Pelletier, B.; Jaffe, B.; Dudley, W.

    2011-01-01

    The recent 29 September 2009 South Pacific and 27 February 2010 Chilean events are a graphic reminder that the tsunami hazard and risk for the Pacific Ocean region should not be forgotten. Pacific Islands Countries (PICs) generally have short (Elsevier B.V.

  15. Exploring the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    tensions experience by sharing platforms by looking at the case of mobile fashion reselling and swapping markets. The final paper combines the perspectives of different sharing economy stakeholders and outlines some of the micro and macro tensions arising in and influencing the organization of these multi...... and to provide a more nuanced understanding of the micro- and macro-level tensions that characterize the sharing economy. This thesis consists of four research papers, each using different literature, methodology, and data sets. The first paper investigates how the sharing economy is diffused and is ‘talked...... into existence’ by the communicative acts of a number of different actors. The second paper looks at how the reality of these narratives is actually experienced by the representatives of one type of sharing platform, i.e., fashion libraries. The third paper further expands the understanding of micro-level...

  16. Exploring the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    Despite the growing interest on the part of proponents and opponents - ranging from business, civil society, media, to policy-makers alike - there is still limited knowledge about the working mechanisms of the sharing economy. The thesis is dedicated to explore this understudied phenomenon...... and to provide a more nuanced understanding of the micro- and macro-level tensions that characterize the sharing economy. This thesis consists of four research papers, each using different literature, methodology, and data sets. The first paper investigates how the sharing economy is diffused and is ‘talked......-level tensions experience by sharing platforms by looking at the case of mobile fashion reselling and swapping markets. The final paper combines the perspectives of different sharing economy stakeholders and outlines some of the micro and macro tensions arising in and influencing the organization of these multi...

  17. Preliminary plant-geographical analysis of the Pacific, as based on the distribution of Phanerogam genera

    NARCIS (Netherlands)

    Balgooy, van M.M.J.

    1960-01-01

    (1) The accompanying map illustrates the hierarchy of the floristic subdivision of the Malaysian-Pacific area and its demarcation against the New World flora. The way of linking it with the mainland of Eastern Asia has not been worked out. Further it has not been attempted to subdivide the Australia

  18. Preliminary plant-geographical analysis of the Pacific, as based on the distribution of Phanerogam genera

    NARCIS (Netherlands)

    Balgooy, van M.M.J.

    1960-01-01

    (1) The accompanying map illustrates the hierarchy of the floristic subdivision of the Malaysian-Pacific area and its demarcation against the New World flora. The way of linking it with the mainland of Eastern Asia has not been worked out. Further it has not been attempted to subdivide the

  19. Legacy and contemporary persistent organic pollutants in North Pacific albatross.

    Science.gov (United States)

    Harwani, Suhash; Henry, Robert W; Rhee, Alexandra; Kappes, Michelle A; Croll, Donald A; Petreas, Myrto; Park, June-Soo

    2011-11-01

    Here we report the first measurements of polybrominated diphenyl ethers (PBDE 47, 99, and 153) alongside 11 organochlorine pesticides (OCPs) and 28 polychlorinated biphenyls (PCBs) in the plasma of albatross from breeding colonies distributed across a large spatial east-west gradient in the North Pacific Ocean. North Pacific albatross are wide-ranging, top-level consumers that forage in pelagic regions of the North Pacific Ocean, making them an ideal sentinel species for detection and distribution of marine contaminants. Our work on contaminant burdens in albatross tissue provides information on transport of persistent organic pollutants (POPs) to the remote North Pacific and serves as a proxy for regional environmental quality. We sampled black-footed (Phoebastria nigripes; n = 20) and Laysan albatross (P. immutabilis; n = 19) nesting on Tern Island, Hawaii, USA, and Laysan albatross (n = 16) nesting on Guadalupe Island, Mexico. Our results indicate that North Pacific albatross are highly exposed to both PCBs and OCPs, with levels ranging from 8.8 to 86.9 ng/ml wet weight and 7.4 to 162.3 ng/ml wet weight, respectively. A strong significant gradient exists between Laysan albatross breeding in the Eastern Pacific, having approximately 1.5-fold and 2.5-fold higher levels for PCBs and OCPs, respectively, compared to those from the Central Pacific. Interspecies levels of contaminants within the same breeding site also showed high variation, with Tern black-footed albatross having approximately threefold higher levels of both PCBs and OCPs than Tern Laysan albatross. Surprisingly, while PBDEs are known to travel long distances and bioaccumulate in wildlife of high trophic status, we detected these three PBDE congeners only at trace levels ranging from not detectable (ND) to 0.74 ng/ml wet weight in these albatross. Copyright © 2011 SETAC.

  20. Eastern Equine Encephalitis

    Science.gov (United States)

    ... bite of an infected mosquito. Eastern equine encephalitis (EEE) is a rare illness in humans, and only ... EEEV have no apparent illness. Severe cases of EEE (involving encephalitis, an inflammation of the brain) begin ...

  1. Pacific Array (Transportable Broadband Ocean Floor Array)

    Science.gov (United States)

    Kawakatsu, Hitoshi; Ekstrom, Goran; Evans, Rob; Forsyth, Don; Gaherty, Jim; Kennett, Brian; Montagner, Jean-Paul; Utada, Hisashi

    2016-04-01

    Based on recent developments on broadband ocean bottom seismometry, we propose a next generation large-scale array experiment in the ocean. Recent advances in ocean bottom broadband seismometry1, together with advances in the seismic analysis methodology, have enabled us to resolve the regional 1-D structure of the entire lithosphere/asthenosphere system, including seismic anisotropy (azimuthal, and hopefully radial), with deployments of ~15 broadband ocean bottom seismometers (BBOBSs). Having ~15 BBOBSs as an array unit for a 2-year deployment, and repeating such deployments in a leap-frog way or concurrently (an array of arrays) for a decade or so would enable us to cover a large portion of the Pacific basin. Such efforts, not only by giving regional constraints on the 1-D structure beneath Pacific ocean, but also by sharing waveform data for global scale waveform tomography, would drastically increase our knowledge of how plate tectonics works on this planet, as well as how it worked for the past 150 million years. International collaborations is essential: if three countries/institutions participate this endeavor together, Pacific Array may be accomplished within five-or-so years.

  2. Australia in the Pacific.

    Science.gov (United States)

    Kennedy, Kerry; Welch, Ian

    1988-01-01

    Discusses Australia's growth since European settlement and its development into a major world trader in industrial and high technology raw materials. Examines the country's expanding relations with New Zealand and other Pacific states which is the outgrowth of the realization that all will gain from greater international cooperation. (GEA)

  3. The East Pacific Rise

    NARCIS (Netherlands)

    NN,

    1961-01-01

    Evidence gathered by expeditions of the University of California’s Scripps Institution of Oceanography during the International Geophysical Year suggests that the East Pacific Rise is one of the largest physical structures on earth. It runs in a sickle-shaped curve from near New Zealand 8,000 miles

  4. The East Pacific Rise

    NARCIS (Netherlands)

    NN,

    1961-01-01

    Evidence gathered by expeditions of the University of California’s Scripps Institution of Oceanography during the International Geophysical Year suggests that the East Pacific Rise is one of the largest physical structures on earth. It runs in a sickle-shaped curve from near New Zealand 8,000 miles

  5. Observational Study Of The Pacific Western Boundary Currents And The Indonesian Throughflow by the CAS Strategic Priority Project

    Science.gov (United States)

    Yuan, D.; Wang, J.

    2014-12-01

    The warm pool in the western Pacific Ocean has significant impact on the evolution of ENSO and the East Asian monsoon. Ocean circulation in the western Pacific Ocean and in Indonesian seas plays an important role in the interannual climate variations and predictability of the tropical Indo-Pacific Ocean. A major observational program of the Chinese Academy of Sciences is recently launched to study the western Pacific Ocean circulation and the warm pool to test these scientific hypotheses. The physical oceanography project called the "Western Pacific Ocean Circulation and the Warm Pool Variability" is by far the largest and the most intensive observational program in history in the western Pacific ocean study. In this talk, the background and scientific hypotheses of the project, the observational design in the western Pacific Ocean, Indonesian seas, and the eastern Indian Ocean region, and some preliminary results of the program will be presented. The talk serves to encourage more scientists to collaborate in the studies of the ocean circulation and climate in the western Pacific and eastern Indian Oceans.

  6. Chimpanzees share forbidden fruit.

    Directory of Open Access Journals (Sweden)

    Kimberley J Hockings

    Full Text Available The sharing of wild plant foods is infrequent in chimpanzees, but in chimpanzee communities that engage in hunting, meat is frequently used as a 'social tool' for nurturing alliances and social bonds. Here we report the only recorded example of regular sharing of plant foods by unrelated, non-provisioned wild chimpanzees, and the contexts in which these sharing behaviours occur. From direct observations, adult chimpanzees at Bossou (Republic of Guinea, West Africa very rarely transferred wild plant foods. In contrast, they shared cultivated plant foods much more frequently (58 out of 59 food sharing events. Sharing primarily consists of adult males allowing reproductively cycling females to take food that they possess. We propose that hypotheses focussing on 'food-for-sex and -grooming' and 'showing-off' strategies plausibly account for observed sharing behaviours. A changing human-dominated landscape presents chimpanzees with fresh challenges, and our observations suggest that crop-raiding provides adult male chimpanzees at Bossou with highly desirable food commodities that may be traded for other currencies.

  7. Managing national forests of the eastern United States for non-timber forest products

    Science.gov (United States)

    James L. Chamberlain; Robert J. Bush; A.L. Hammett; Philip A. Araman

    2000-01-01

    Over the last decade, there has been a growing interest in the economic and ecological potential of non-timber forest products. In the United States, much of this increased interest stems from drastic changes in forest practices and policies in the Pacific Northwest region, a region that produces many non-timber forest products. The forests of the eastern United States...

  8. Range extension and morphological characterization of rhodolith-forming species (Corallinales, Rhodophyta) from shallow water in the Mexican South Pacific

    Science.gov (United States)

    Peralta-García, Edith Concepción; Rosas-Alquicira, Edgar Francisco

    2014-12-01

    Living rhodolith beds are widely distributed along the Eastern Pacific ocean. Despite their widespread distribution, little is known about the rhodolith-forming species from shallow water in the Mexican South Pacific. Many taxonomic and morphological studies about rhodoliths have been carried out in the Gulf of California, where the forming species belong to the Hapalidiaceae and Corallinaceae families. This paper is the first report on the occurrence of the rhodolith-forming Hapalidiaceae species Lithothamnion muelleri and Phymatolithon repandum at three sites in the Mexican South Pacific. The branch density, maximum length and sphericity were measured for each determined species. Rhodoliths were distributed between 4 and 6 m depth, but differences in the branch density between species and sites were not found. Finally, the present record of L. muelleri fills the gap in the species distribution along the Eastern Pacific ocean, while the record of P. repandum is the first of the species in the region.

  9. Knowledge grows when shared

    DEFF Research Database (Denmark)

    Elbæk, Mikael Karstensen

    2010-01-01

    Knowledge is one of the few commodities that don’t devalue when used. Actually knowledge grows when shared and the free online access to peer-reviewed scientific publications is a potent ingredient the process of sharing. The sharing of knowledge is facilitated by the Open Access Movement. However...... infrastructure for Open Access was launched in Ghent, Belgium. This project and initiative is facilitating the success of the Open Access Pilot in FP7 as presented earlier in this journal. In this brief article I will present some of the most interesting issues that were discussed during the first session...

  10. Global resource sharing

    CERN Document Server

    Frederiksen, Linda; Nance, Heidi

    2011-01-01

    Written from a global perspective, this book reviews sharing of library resources on a global scale. With expanded discovery tools and massive digitization projects, the rich and extensive holdings of the world's libraries are more visible now than at any time in the past. Advanced communication and transmission technologies, along with improved international standards, present a means for the sharing of library resources around the globe. Despite these significant improvements, a number of challenges remain. Global Resource Sharing provides librarians and library managers with a comprehensive

  11. Too Much Information Sharing?

    DEFF Research Database (Denmark)

    Ganuza, Juan José; Jansen, Jos

    2013-01-01

    By using general information structures and precision criteria based on the dispersion of conditional expectations, we study how oligopolists’ information acquisition decisions may change the effects of information sharing on the consumer surplus. Sharing information about individual cost...... parameters gives the following trade-off in Cournot oligopoly. On the one hand, it decreases the expected consumer surplus for a given information precision, as the literature shows. On the other hand, information sharing increases the firms’ incentives to acquire information, and the consumer surplus...... increases in the precision of the firms’ information. Interestingly, the latter effect may dominate the former effect....

  12. Pacific trade winds accelerated by aerosol forcing over the past two decades

    Science.gov (United States)

    Takahashi, Chiharu; Watanabe, Masahiro

    2016-08-01<