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The distribution of hydrogen peroxide was determined at 28 stations in four transects across the No rthern So uth C hina Sea S helf-sea (NoSoCS) in June 2010. The average concentration in the top 10 m ranged between 0.063 and 0.231 µM. Among the hydrographic regimes: the inner shelf outside the influence of upwelling, the inner shelf under the influence of upwelling, the middle shelf, the outer shelf and the open South China Sea, the highest concentration was found in the day-time in the inner shelf outside of the influence of upwelling and the lowest concentration was found in the night-time in the inner shelf under the influence of upwelling. The average concentration at the day-time stations in each hydrographic regime was invariably higher than the corresponding concentration at the night-time stations. Across the shelf, the concentration was the highest in the inner shelf. The variations in the concentrations of hydrogen peroxide and total organic carbon (TOC) in the different hydrographic regimes followed a similar pattern. All these behaviors are consistent with the photochemical production of hydrogen peroxide, using dissolved organic matter as the chromophore, as a primary control on its occurrence in the surface waters. Moreover, at day-time stations at different locations in the NoSoCS and at a single location sampled through the day, the relationship between the concentration of hydrogen peroxide and the product of the concentration of TOC and the time-integrated irradiance at the time of sample collection fell on two distinct linear lines with different slopes and intercepts: one for mostly the inner and middle shelf waters and the other for mostly the water in the open northern SCS. These relationships suggest that the light history, the pre-existing concentration of hydrogen peroxide, and, the concentration and the photochemical efficiency of the dissolved organic matter in the production of hydrogen peroxide play major roles in determining the temporal and spatial variations in the concentration of hydrogen peroxide in the surface waters in the day-time. In the sub-surface, a notably large fraction, about one-third, of the profiles of hydrogen peroxide did not follow the typical distribution of a quasi-exponential decrease in concentration with depth. Almost all the profiles at the stations in the slope where the internal waves were most active were atypical. At these stations, the concentration of hydrogen peroxide was generally elevated down to about 100 m, well beyond the depths where solar irradiance was plentiful. Superimposed on these elevated concentrations was a persistent sub-surface maximum, with concentrations reaching about 0.5 µM, at 80 m. While the origin of these atypical distributions is not yet clear, dark biological production and the action of internal waves conceivably could have contributed to their occurrence. [ABSTRACT FROM AUTHOR]

Abstract: Macrofouling is a common problem when deploying underwater instrumentation for long periods of time. It is a problem which can effect scientific experiments and monitoring missions though the creation of artificial reefs (thus increasing local biological activity) and reduce the quality of scientific data. Macrofouling is an issue typically considered to be restricted to the photic zones and is absent or negligible in the deep sea. To the contrary, the recovery of an accidentally lost deep-sea lander after 3 years submergence at 3960m on the Mid-Atlantic Ridge (North Atlantic) revealed dense colonisation of macrofouling organisms. These organisms were found attached to all surfaces of the lander regardless of orientation and materials. The occurrence of such deep-sea macrofouling should be carefully investigated given the recent developments in long-term deep-sea observatory networks. [Copyright &y& Elsevier]

Abstract: Free-drifting icebergs in the Weddell Sea are expected to affect the surrounding marine ecosystem. Sampling associated with iceberg C-18a, a large tabular, free-drifting iceberg in the NW Weddell Sea, carried out from 10 March to 7 April 2009, was designed to test the hypothesis that the iceberg''s presence modified phytoplankton composition and abundance. Areas that define a gradient of possible iceberg influence were sampled for phytoplankton: stations close (<1km) and far (18km) from iceberg C-18a, an area with numerous small icebergs, Iceberg Alley, and a control site 74km away. Quantitative samples were obtained from Niskin bottles and counted with an inverted microscope for species abundance. Qualitative samples were collected with nets from the ship''s seawater intake. Taxonomic determinations were performed with light and electron microscopy. Overall, diatoms dominated in the mixed layer (surface-∼40m) and unidentified small flagellated and coccid cells at depth (∼100m). Fragilariopsis nana, a diatom 2.4–15.5μm in length, dominated numerically the phytoplankton and was most abundant at the control area. The iceberg''s effect on phytoplankton composition was consistent with the hypothesis that they facilitate phytoplankton communities enriched in diatoms, as found in other productive areas of Antarctica. Near the iceberg, diatoms were most abundant, principally at depth, while small flagellate concentration diminished. However, total phytoplankton abundance was lowest at Iceberg Alley in the area of highest meltwater contribution, as indicated by low mean temperature in the mixed layer, and highest at the control site. These results suggest that during austral fall, low growth or high zooplankton grazing could be counteracting the positive effect by icebergs on phytoplankton biomass, otherwise observed in summer months. [Copyright &y& Elsevier]

Abstract: We report on the late winter oceanography observed beneath the Antarctic sea ice offshore from the Sabrina and BANZARE coast of Wilkes Land, East Antarctica (117–128°E) in September–October 2007 during the Sea Ice Physics and Ecosystem eXperiment (SIPEX). A pilot program using specifically designed ‘through-ice’ conductivity-temperature-depth (CTD) and acoustic Doppler current profiling (ADCP) systems was conducted to opportunistically measure water mass properties and ocean currents at major ice stations. Additional water mass properties across the survey region were collected from Ice-Argo floats deployed during the voyage north of the 3000m isobath. The mean drift of the floats was along the slope to the west with the Antarctic Slope Current. Vertical profiles of the potential temperature reveal the deepest winter mixed layer (WML) in the western sector of the survey northwest of the Dalton Iceberg Tongue polynya. The meridional structure of the Antarctic Slope Front, i.e. the monotonic shoaling of the WML across the upper continental slope, is found to be similar to the previous observations in summer. A strong bottom-intensified intrusion of modified Circumpolar Deep Water (mCDW) as warm as 0°C was detected beneath the fast ice south of the continental shelf break at 118°E. An mCDW intrusion of similar strength was detected near this location in the austral summer of 1996. We hypothesise that there is a persistent supply of mCDW and associated ocean heat flux to this region of the continental shelf that is capable of migrating to the grounding lines of the nearby Totten Glacier and Moscow University Ice Shelf. There was no detection of locally formed dense shelf water capable of forming Antarctic Bottom Water at the shelf break locations sampled despite the number of minor polynyas across this region. Ocean current measurements, limited to a maximum period of 24h and 50–100m depth by the relative scarcity of backscatter, found increased mean vertical speeds at the offshore stations (6–17cms−1) relative to the shelf break (2.3–6.4cms−1). The diurnal variation in the ADCP range reflected the diel migration of zooplankton occurring beneath the sea ice in late winter, with greater range/abundance offshore. Concurrent time series of wind, ocean current and their influence on sea ice drift from global positioning system (GPS) compass measurements were examined but the length of data acquisitions limited the applicability of this analysis. [Copyright &y& Elsevier]

Focuses on a study that determined the call densities of total coccolithophore ecology at the HOT station ALOHA in Hawaii. Materials and methods used; Oceanographic conditions during 1994-1996; Total coccolithopore abundances; Ecological analyses and interpretation.

Presents information on a study that provided annual and seasonal averages for migrant-mediated export fluxes at Station ALOHA in Hawaii, a time-series sampling site in North Pacific. Materials and methods used; Results on migrant biomass; Composition of the migratory community.

Deals with a study that examined the seasonal and interannual variability in mesozooplankton biomass structure at Ocean Station ALOHA in Hawaii. Materials and methods used; Error estimates; Seasonal patterns at the station.

Deals with a study that investigated the errors in total particulate organic carbon (POC) measurements in the Bermuda Atlantic Time-series Study (BATS) site. Materials and methods; Biogeochemical results of the POC measurements at the BATS site; Potential errors in POC estimates and test of viable bacterial cells passing a GF/F filter.

Deals with a study that presented an overview of patterns in ocean biology and biogeochemistry over a decade at the Bermuda Atlantic Time-series Study (BATS) site. Purpose of the United States Joint Global Ocean Flux Study; Methodology; Hydrographic and biogeochemical variability at BATS.

Deals with a seasonal study that examined the significance of nitrogen fixation by Trichodesmium specie at the Bermuda Atlantic Time-series Study site (BATS). Materials and methods used; Abundance of Trichodesmium species at BATS.

Focuses on a study that examined the seasonal and interannual variability in deep ocean particle fluxes at the Oceanic Flux Program and Bermuda Atlantic Time Series sites in the western Sargasso Sea. Description of the study area; Methodology; Mass fluxes at different depths; Seasonality of mass flux.

Focuses on the Canadian Joint Global Ocean Flux Study in the northeast subarctic Pacific. High Nitrate Low Chlorophyll regions; Characteristics of the regions; Analyses of long-time series data sets from Ocean Station Papa and other stations in the coastal and open ocean.

Presents a review of the oceanographic properties in the vicinity of Ocean Station Papa (OSP) in Canada. Description of the physical and chemical properties of the upper ocean both at OSP and along Line P, a series of oceanographic stations; Impacts of the 1982 El Nio; Possible effects of physical and chemical variability on ecology.

Editorial. Focuses on the interpretations of biogeochemical processes from the United States Joint Global Ocean Flux Study (US JGOFS) in the Bermuda and Hawaii time-series sites. Creation of time-series oceanography studies; Contribution of the US JGOFS to oceanographic experiments.