Surface Waters Of Pacific Ocean Research Articles

Diverse Marine T4-like Cyanophage Communities Are Primarily Comprised of Low-Abundance Species Including Species with Distinct Seasonal, Persistent, Occasional, or Sporadic Dynamics.

Cyanophages exert important top-down controls on their cyanobacteria hosts; however, concurrent analysis of both phage and host populations is needed to better assess phage-host interaction models. We analyzed picocyanobacteria Prochlorococcus and Synechococcus and T4-like cyanophage communities in Pacific Ocean surface waters using five years of monthly viral and cellular fraction metagenomes. Cyanophage communities contained thousands of mostly low-abundance (<2% relative abundance) species with varying temporal dynamics, categorized as seasonally recurring or non-seasonal and occurring persistently, occasionally, or sporadically (detected in ≥85%, 15-85%, or <15% of samples, respectively). Viromes contained mostly seasonal and persistent phages (~40% each), while cellular fraction metagenomes had mostly sporadic species (~50%), reflecting that these sample sets capture different steps of the infection cycle-virions from prior infections or within currently infected cells, respectively. Two groups of seasonal phages correlated to Synechococcus or Prochlorococcus were abundant in spring/summer or fall/winter, respectively. Cyanophages likely have a strong influence on the host community structure, as their communities explained up to 32% of host community variation. These results support how both seasonally recurrent and apparent stochastic processes, likely determined by host availability and different host-range strategies among phages, are critical to phage-host interactions and dynamics, consistent with both the Kill-the-Winner and the Bank models.

Marine Group II Euryarchaeota Contribute to the Archaeal Lipid Pool in Northwestern Pacific Ocean Surface Waters.

Planktonic archaea include predominantly Marine Group I Thaumarchaeota (MG I) and Marine Group II Euryarchaeota (MG II), which play important roles in the oceanic carbon cycle. MG I produce specific lipids called isoprenoid glycerol dibiphytanyl glycerol tetraethers (GDGTs), which are being used in the sea surface temperature proxy named TEX86. Although MG II may be the most abundant planktonic archaeal group in surface water, their lipid composition remains poorly characterized because of the lack of cultured representatives. Circumstantial evidence from previous studies of marine suspended particulate matter suggests that MG II may produce both GDGTs and archaeol-based lipids. In this study, integration of the 16S rRNA gene quantification and sequencing and lipid analysis demonstrated that MG II contributed significantly to the pool of archaeal tetraether lipids in samples collected from MG II-dominated surface waters of the Northwestern Pacific Ocean (NWPO). The archaeal lipid composition in MG II-dominated NWPO waters differed significantly from that of known MG I cultures, containing relatively more 2G-OH-, 2G- and 1G- GDGTs, especially in their acyclic form. Lipid composition in NWPO waters was also markedly different from MG I-dominated surface water samples collected in the East China Sea. GDGTs from MG II-dominated samples seemed to respond to temperature similarly to GDGTs from the MG I-dominated samples, which calls for further study using pure cultures to determine the exact impact of MG II on GDGT-based proxies.

Comparison of community structures between particle-associated and free-living prokaryotes in tropical and subtropical Pacific Ocean surface waters

The subtropical and tropical regions of the Pacific Ocean are less productive than other oceanic regions. Although particle association should be an important strategy for heterotrophic prokaryotes to survive in such environments, we have little information on particle-associated (PA) prokaryotes in these regions. The specific aim of this study was to determine bacterial and archaeal community structures in the PA assemblage in comparison to the free-living (FL) assemblage in the North Pacific Subtropical Gyre, the South Pacific Subtropical Gyre, and an eastern equatorial region of the Pacific Ocean. Community profiles and phylogenetic identities were obtained by denaturing gradient gel electrophoresis, 454-pyrosequencing, and cloning followed by Sanger sequencing of 16Sr RNA gene amplicons. The distribution patterns of some abundant groups in three regions and two lifestyles (PA and FL) are shown in this study. Also, the PA community structures of bacteria differed from the FL ones and exhibited higher diversity than the FL ones, while the archaeal community structures did not show significant differences between PA and FL assemblages. We found that specific phylotypes of Gammaproteobacteria and Flavobacteria were abundant in PA bacterial assemblages, suggesting that they prefer to attach and consume particulate organic matter. In summary, the surface seawater PA assemblages represent very different bacterial and archaeal community structures between three different oceanic regions, each of which had distinct PA and FL community structures. These results imply that environmental factors determine microbial community structures.

Carbon conundrum, climate change, CO2 capture and consumptions

Carbon dioxide (CO2) emission and absorption components consist of biosphere, hydrosphere, atmosphere, lithosphere and fossil fuels. CO2 flow rates are governed by large scale fluid dynamic, thermodynamic and radio-active transfer processes. This results in dynamic flow of CO2 over land and oceans affecting regional climates. Convective uptake of CO2 from Asia flows at high altitude to America and then returns sweeping the local emissions back to Asia. In this process the bulk clouds of CO2 are absorbed in cold Pacific Ocean surface waters near America, causing regional cooling effect. Dynamic thermohaline circulations take away the dissolved carbon to warmer Asian waters maintaining the global carbon balance. Monsoon winds sweep Himalayan valley smoke and CO2 to Arabian Sea causing regional warming. Atmospheric CO2 and dissolved water carbon concentrations cause regional warming and cooling effects. Global carbon circuit may cause regional warming and cooling, irrespective of local emissions. In this study, nature's response to higher concentration of CO2 and its direct removal from atmosphere or sequestration at source is presented. This paper describes global carbon balance, regional climate changes and carbon fix alternatives by developing industrial use of CO2. ASHREA has envisioned 11 new future refrigerants for evacuated glass tube solar water heaters. Our simulation results show that supercritical CO2 is an optimum natural refrigerant in terms of thermodynamic and heat transfer properties in the range of −20 to 30 and 30–70°C. We demonstrated the utilization of captured CO2 as mediating fluid for refrigeration and solar water heating applications.

Spatial Distribution of the Particulate Organic Ligand in the South Pacific Ocean Surface Waters

Strong organic ligand in oceanic Particulate Matter (PM), as determined from amount of thorium adsorption onto PM in 0.1 M HCl, was measured for surface waters of mid-latitude region (ca. 32.5°S) in the South Pacific Ocean. The Particulate Organic Ligand (POL) concentrations in surface waters of the South Pacific, ranging from 2.6 to 13.3 nM, showed a longitudinal variation with low concentrations in the South Pacific subtropical gyre (180°-100°W) and high in the eastern South Pacific. The POL concentrations in the South Pacific surface waters increased with increasing nutrients (nitrate and phosphate) and chlorophyll concentration, which means that POL in surface waters is closely related to biological activity in the ocean; the high POL occurs in highly productivity region, whereas the low POL appears in the oligotrophic ocean. This is a first basin-scale measurement of POL in surface waters of the South Pacific. POL is a useful tool for better understanding of biological activity, particle dynamics and trace metal cycling in surface layer, if we have more detail knowledge on chemical and biogeochemical properties of POL, as do factors controlling spatial and temporal variability.

Long-term simulations of the 137Cs dispersion from the Fukushima accident in the world ocean

The LAMER calculation code was used for simulation of the distribution of 137Cs released after the Fukushima accident into the Pacific and Indian Oceans. The maximum 137Cs concentration predicted for surface waters of the open NW Pacific Ocean in 2012 (21Bq/m3 at 38°N, 164°E) will be comparable to that observed during the early 1960s after atmospheric nuclear weapons tests. The 137Cs in surface waters of the Pacific Ocean will reach the US coast 4–5y after the accident, however, the levels will be low (<3Bq/m3). All the North Pacific Ocean will be labeled with Fukushima 137Cs 10y after the accident with concentrations below 1Bq/m3. Thirty years after the accident the 137Cs levels in the Pacific and Indian Oceans will be below 0.1Bq/m3, i.e. undetectable on the present global fallout background. The effective dose commitment with ingestion of marine biota found in 2012 in the open NW Pacific Ocean was estimated to be 1.7μSv/y, mostly delivered by 134,137Cs. The estimated dose is by about a factor of 500 lower than the present dose limit for the public.

Desalination technology waste streams: Effect of pH and salinity on metabolism of marine microbial assemblages

Effluents from desalination technologies may influence natural bacterial assemblages due to changes in salinity, pH, dissolved organic carbon concentration (DOC), DOC quality and cellular hydrostatic pressure. Salinity, pH, and pressure change effects on heterotrophic bacterial production (as measured by leucine incorporation) were examined in experiments with surface water from the Delaware Bay, Atlantic Ocean and Pacific Ocean. Bacterial production decreased by 57–67% when salinity of Atlantic Ocean and Delaware Bay surface water samples were increased from ambient to 60 PSU. Decreasing ambient seawater pH from 8.0 to below 5.0 with CO 2 gas reduced production by 96–100%. Decreasing seawater pH by 1.5 units at 33 PSU caused equivalent inhibition to increasing salinity by 27 PSU (pH 8.0). Bacterial production in Pacific Ocean surface water pressurized for 72 h was decreased 40% by increasing salinity, when measured 1 h after decompression. However, production increased 43% with increasing salinity when measured 24 h after decompression. One explanation for these divergent effects between the 1- and 24-h sampling at ambient pH may be community adaptation. Strains amongst the natural assemblage that survived the pressurization by saturating their membrane phospholipids would likely be better adapted to compete for available nutrients under elevated salinity.

Climate change triggered sedimentation and progressive tectonic uplift in a coupled piedmont–axial system: Cuyama Valley, California, USA

AbstractChannels on the north‐facing piedmont of the Sierra Madre range in Cuyama Valley, California have alternated between three process regimes during the late Quaternary: (1) vertical incision into piedmont alluvium and older sedimentary deposits; (2) lateral erosion; and (3) sediment accumulation. The state of the piedmont system at a given time has been controlled by upstream sediment flux, regional tectonic uplift and incision of the axial Cuyama River.To better understand the timing and to attempt to interpret causes of past geomorphological processes on the Sierra Madre piedmont, we mapped the surficial geology and dated alluvial deposits using radiocarbon, cosmogenic and optical dating methods. Four primary episodes of sedimentation have occurred since ca. 100 ka, culminating in the most recent period of extensive piedmont sedimentation between 30 and 20 ka. Fill terraces in Cuyama Valley formed by piedmont sediment accumulation followed by vertical incision and lateral erosion are fairly planar and often mantle strath bedrock surfaces. Their vertical spatial arrangement is a record of progressive regional tectonic uplift and concomitant axial Cuyama River channel incision migrating up tributary piedmont channels. Subparallel longitudinal terrace profiles which have a linear age–elevation relationship indicate that multiple episodes of climatically controlled sedimentation overprints ∼1 m kyr−1 of regional uplift affecting the Cuyama River and its tributaries.Sedimentation was probably a result of increased precipitation that caused saturation landsliding in steep catchments. It is possible that increased precipitation during the Last Glacial Maximum was caused by both continental‐scale circulation pattern reorganization and increased Pacific storm frequency and intensity caused by ‘early warming’ of nearby Pacific Ocean surface waters. Older episodes of piedmont sedimentation are difficult to correlate with specific climate regimes, but may correlate with previous periods of increased precipitation. Copyright © 2007 John Wiley &amp; Sons, Ltd.

Plutonium and 137Cs in surface water of the South Pacific Ocean

The present plutonium and 137Cs concentrations in South Pacific Ocean surface waters were determined. The water samples were collected in the South Pacific mid-latitude region (32.5 degrees S) during the BEAGLE expedition conducted in 2003-04 by JAMSTEC. 239,240Pu concentrations in surface seawater of the South Pacific were in the range of 0.5 to 4.1 mBq m(-3), whereas 137Cs concentrations ranged from 0.07 to 1.7 Bq m(-3). The observed 239,240Pu and 137Cs concentrations in the South Pacific were almost of the same level as those in the North Pacific subtropical gyre. The surface 239,240Pu in the South Pacific subtropical gyre showed larger spatial variations than 137Cs, as it may be affected by physical and biogeochemical processes. The 239,240Pu/137Cs activity ratios, which reflect biogeochemical processes in seawater, were generally smaller than that observed in global fallout, except for the most eastern station. The 239,240Pu/137Cs 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 137Cs 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 137Cs 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.

Chemical forms and dynamics of amino acid-containing particulate organic matter in Pacific surface waters

Particulate combined amino acids (PCAA) are the most abundant identified constituents of particulate organic matter (POM) in Pacific Ocean surface waters, but their chemical forms are unclear. In the present study, chemical characterization of amino acid-containing materials in surface POM from subarctic to subtropical waters along 165 °E in the Pacific was carried out by one- and two-dimensional gel electrophoresis. At least four chemical forms of amino acid-containing POM were distinguished: proteins, acidic materials containing peptides, protein/peptide-specific dye-stainable low-molecular-mass materials (stainable materials) and non-stainable materials, all of which were considered to be major components of detrital POM. Seventeen distinct protein containing components were distinguished in samples across the transect. A majority of stainable materials was estimated to comprise 6–8 amino acid residues, while less than six amino acid residues made up the non-stainable materials. Among the four chemical forms, acidic materials and non-stainable materials were major components, accounting for 31–42% and 49–63% of PCAA, respectively, along the transect. Proteins were common, but they were quantitatively less than 2% of PCAA. Stainable materials were regionally variable and more abundant in subarctic waters than in subtropical waters. The mechanistic processes by which such amino acid-containing POM occurs as detrital POM are discussed.

Nd concentration and isotopic composition distributions in surface waters of Northwest Pacific Ocean and its adjacent seas

Nd isotopic composition and concentration distributions were determined in surface waters of the Northwest Pacific Ocean and its adjacent seas, i.e., the Okhotsk and Japan Seas. The Okhotsk and Japan Seas samples showed higher Nd concentrations (19∼31 pmol/kg) than the Northwest Pacific Ocean samples, suggesting a large amount of Nd input from the land areas surrounding the Okhotsk and Japan Seas. Although the Nd isotopic composition data were limited for those regions, each oceanic area showed a distinctive value. The lone sample from the Okhotsk Sea had radiogenic Nd (eNd = −3.6) that was comparable to samples from the Pacific Ocean, indicating a large amount of radiogenic Nd supply from the Kuril Islands. On the other hand, the Japan Sea samples had the most highly unradiogenic Nd (eNd = −8.9∼−7.2). The southernmost sample had the most negative value, due to the influence of the Tsushima Warm Current (TWC) having a low eNd value. The latitudinal distributions of Nd isotopic composition and concentration in the surface waters of the Northwest Pacific Ocean showed marked variations. Nd concentration was low at low latitudes (3∼8 pmol/kg) and was increased with increasing latitude (16∼20 pmol/kg). On the other hand, Nd isotopic composition showed a mid-latitude minimum (eNd = ∼−6) and high eNd values at low and high latitudes (eNd = −2∼−1). The distribution of the eNd values seemed to be controlled by three currents: Kuroshio Extension, Oyashio Current and North Equatorial Current (NEC). The Kuroshio Extension, which showed a low eNd value, seemed to play an important role in transporting continentally derived Nd to the central Pacific. The Oyashio Current and NEC are supplied with large amounts of radiogenic Nd from the Kuril and Aleutian Islands, and the Hawaiian Islands, respectively. Based on the Nd isotopic composition and concentration distributions, we calculated the radiogenic Nd flux to the Pacific Ocean surface waters and estimated the Nd residence time. Our calculation suggested that the radiogenic Nd flux required to account for the Nd isotopic composition is higher than 70% of the unradiogenic Nd flux including Nd remobilization from coastal and shelf sediments and atmospheric input. It was also revealed that a large Nd remobilization flux is necessary to attain a global Nd residence time of ∼400 y as estimated in previous studies.

Accumulation and Export of Dissolved Organic Carbon in Surface Waters of Subtropical and Tropical Pacific Ocean

Dissolved organic carbon (DOC) concentrations in surface waters of the Pacific Ocean during October–November, 1995, were determined using a high-temperature combustion method. The DOC in the surface mixed-layer was approximately homogeneous with a concentration between 55 and 89 µmol C l−1. This homogeneity indicates that there is a strong control of the vertical distribution of DOC by mixing processes. The DOC concentrations in the mixed-layer in the subtropical region were up to 27 µmol C l−1 higher than in the tropical region. This difference reflects the subtropical accumulation and the tropical export of DOC. There is a significant positive correlation between DOC and chlorophyll a concentrations in the mixed-layer of the North Pacific subtropical region, suggesting that phytoplankton is the primary source of DOC accumulated in this region. Calculations using simple box models suggest that DOC export in the tropical region (0–50 m depth, 10°N-10°S, along 160°W) occurs primarily by poleward advection at a rate of 0.5–3 mmol C m−2day−1. A comparison with estimates of the export rate of particulate organic carbon published in previous studies leads us to conclude that DOC export may contribute less to the carbon budget in the tropical region than has recently been supposed.

Northeast North Pacific Ocean: Surface current pattern shifts during the spring

This work is a study of the interaction of the wind and the sea where easterly moving geostrophic flow becomes eastern boundary currents. To be as synoptic as possible, a satellite time series study (1983–1989) and an oceanographic survey (1989) concentrated on the Pacific Ocean surface waters adjacent to the northwest coast of North America. The hypothesis tested was that the changes in temperature contours of the sea surface infer a shift in current patterns. Of special interest are the surface current patterns during the spring transitional period (1 March–15 June). This is the time when the California current begins to dominate the eastern boundary currents, and biological production increases. At this time, the predominant wind patterns over the North Pacific change. These changes affect the water masses where the West Wind Drift becomes the California Current. By using the Advanced Very High Resolution Radiometer (AVHRR) aboard NOAA's polar orbiter satellites, a pattern of current shifts over time is measurable. The results from analyzing 53 images over 7 years show a noticeable and distinct shift in surface temperature patterns during the spring period. This pattern shift was visible over time and space, and reflects the effect of the wind in changing the pattern of surface water current flow. Although limited in time and space, the ship-deployed instruments, also, reflect these changes and allow a look at the physical processes in the mixed layer.

Total dissolved nitrogen and phosphorus concentrations at US-JGOFS station ALOHA: Redfield reconciliation

Abstract Twenty-two water column profiles (0–4500 m) of total dissolved nitrogen (TDN) and phosphorus (TDP) concentrations have been collected over a 2-year period at the US-JGOFS time-series Station ALOHA. These data indicate that the N:P molar ratio (mean, 16.74: standard deviation, 2.95; n = 417 ) in the central Pacific Ocean is not significantly different from that predicted a priori based upon current models of the bioelemental composition of plankton. An examination of the literature and new data from our laboratory using direct high-temperature combustion methods for both TDP and TDN support the validity of historical oceanic analyses. Despite the substantially higher DOC values in oligotrophic Pacific Ocean surface waters, TDN (and consequently dissolved organic nitrogen [DON]) and TDP (and consequently dissolved organic phosphorus [DOP]) do not appear to have been underestimated.

El Niño Returns

El Niño, a climatic disturbance that shifts much of the world's weather pattern every 2–7 years, has returned and is probably near the midpoint of its expected 18‐month life cycle, according to an announcement by the National Weather Service (NWS) of the National Oceanic and Atmospheric Administration (NOAA). This El Niño appears to be much milder than its predecessor 4 years ago, from April 1982 to July 1983. That event, the worst in more than 100 years, caused floods and droughts that led to more than 1000 deaths and $2 billion to $8 billion in economic losses.The phenomenon comes about when equatorial winds that normally blow the Pacific Ocean's surface waters from east to west weaken or reverse themselves. The warm surface waters then flow from west to east. Results include a decrease in rainfall in the Philippines, Indonesia, Australia, New Guinea, and Southern Africa; increased rainfall in the South American coast, the southeastern United States, and eastern Africa; and milder than normal weather in the U.S. Pacific Northwest, western Canada, and Alaska. The current El Niño was successfully predicted by at least three different scientific models, according to The New York Times, although the event began somewhat later than expected.

Determination of barium in sea water by graphite furnace atomic absorption spectrometry after preconcentration and separation by solvent extraction.

The determination of barium at a trace level by graphite furnace atomic absorption spectrometry was described. The reproducibility was improved to 3.6 % by the use of pyrolytic graphite coated furnaces. Moreover, the preconcentration and separation of barium from sea water by solvent extraction were investigated and applied to the determination of barium in sea water by the graphite furnace atomic absorption spectrometry. Barium was quantitatively separated and concentrated from interfering elements in sea water by the use of a mixture of 1-phenyl-3-methyl-4-benzoylpyrazol-5-one and tri-n-octylphosphine oxide as extractants, and the mean value of the recovery was 98.6 %. Barium in the Pacific Ocean surface water was determined and 5.6 μg dm -3 was found.

10Be concentration and residence time in the ocean surface layer

The concentration of 10Be in Pacific Ocean surface water has been measured by nuclear accelerator spectrometry to be ∼740 atoms/cm 3. This value, which is much less than the 10Be concentration in precipitation, suggests that particle scavenging of Be in the surface layer is important. The present work demonstrates the feasibility of making detailed horizontal and vertical distribution measurements of 10Be in the oceans, using the accelerator technique.

Rhenium: Its concentration in Pacific Ocean surface waters

The average Be concentration in four widely-spaced Pacific Ocean surface seawater samples was found to be 0.0084 μg/ l ± 17%. The amount of Re found in (or on) a brown kelp plant ( Macrocystisintegrifolia) was 0.022 μg/ g freeze-dried plant. The Re in seawater was found to exist as an extractable species. The concentration of Re in seawater had not previously been investigated ( HØgdahl, 1963) and was expected to be only a trace. A procedure was developed to extract Re from seawater and to concentrate it for measurement by neutron activation analysis. The amount of Re in a sample was determined by the comparator method based on the reaction 185Re(n, γ) 186Re. Details of the determination of very small amounts of Re in various materials by activation analysis are given in, e.g. Morris and Fifield (1961), Morgan (1965), Palino (1965), Ishida et al. (1966). Samples of Pacific Ocean surface water from an off-shore station near San Francisco (Farallon Islands) and from three weather stations in the Pacific were analyzed for Re. Rhenium was determined also in several samples of sea salts from evaporated seawater to provide a reference point for estimation of the fraction of Re present in seawater as an extractable species. A brown kelp plant, Macrocystisintegrifolia, which is known to concentrate iodine ( kelly and Baily, 1951), was analyzed for Re. Rhenium has been shown to behave similarly to iodine in its deposition in certain biological systems, e.g. the thyroid ( baumann et al., 1949).

Meridional distribution of temperature-salinity characteristics of Pacific Ocean surface water : Lynn R. J., 1964. J. Mar. Res., 22 (1): 70–82

Meridional distribution of temperature-salinity characteristics of Pacific Ocean surface water : Lynn R. J., 1964. J. Mar. Res., 22 (1): 70–82