OceanObs'09 - Additional Contributions

 
Session: Biochemistry and ecosystems (02C)


A JOINT ICES-IOC STUDY GROUP ON NUTRIENT STANDARDS
Aoyama, Michio1; Dickson, Andrew G.2; Hydes, David J.3; Murata, Akihiko4; Oh, Jae5; Roose, Patrick6; Woodward, E. Malcolm S.7
1MRI, JAPAN;
2Scripps Institution of Oceanography, UNITED STATES;
3National Oceanography Centre, Southampton, UNITED KINGDOM;
4Japan Agency for Marine-Earth Science and Technology, JAPAN;
5IAEA-Marine Environment Laboratories, MONACO;
6MUMM, BELGIUM;
7Plymouth Marine Laboratory, UNITED KINGDOM

The comparability and traceability of nutrients data in the world's oceans are one of primary importance to Marine Science, and to the studies of Global Change. The IOC-ICES joint Study Group on Nutrient Standards, SGONS, is established in 2009. The work of the SGONS would enable better comparability between data sets measured at different times, and by different laboratories, so it would be possible to investigate, reliably, the change of nutrients distributions in the ocean, and the tight coupling between the nitrogen and phosphorus cycles in the ocean with that of carbon.

 
An expanding observatory to monitor hypoxia in the Northern California Current System
Barth, John; Shearman, R. K.; Chan, F.; Pierce, S. D.; Erofeev, A. Y.; Brodersen, J.; Levine, M. D.; Page-Albins, K.; Risien, C.; Rubiano-Gomez, L.; Waldorf, B. W.
Oregon State University, UNITED STATES

Near-bottom waters over the inner shelf (< 50 m water depth) off central Oregon, U. S. A., have been increasingly hypoxic (dissolved oxygen < 1.4 ml/l) over the last 8 years, including the appearance of anoxia in summer 2006. The appearance of near-bottom, inner-shelf hypoxia is driven by upwelling of low-oxygen and nutrient-rich sourcewater onto the continental shelf, followed by the decay of organic matter raining down from surface phytoplankton blooms. Through a combination of ship sampling, moorings and autonomous underwater vehicle gliders, we have been measuring dissolved oxygen with increasing temporal and spatial coverage. For longer term context, we use historical observations along the Newport Hydrographic Line sampled since the 1960s. The mooring array spans the inner shelf (15 m isobath) along 60 km of Oregon coastline and includes two mid-shelf (70-80 m isobath) moorings. Two of these moorings return near-bottom dissolved oxygen, as well as temperature and salinity, in near real-time. Since April 2006, we have occupied the Newport Hydrographic Line nearly continuously using two Webb Research Corporation 200-m Slocum electric gliders and a 1000-m Seaglider. In total, gliders have been at sea for 1,253 days (3.4 years), sampled over 400 cross-shelf sections, collected in excess of 110,000 vertical profiles and traveled over 28,000 km. We analyze data from this observatory to show how the severity of inner-shelf hypoxia varies year-to-year due to changes in upwelling sourcewater properties and the characteristics of wind-driven upwelling.

 
High Frequency Monitoring of pCO2 using a CARIOCA sensor in a Temperate coastal ecosystem (2003-2009)
Bozec, Y1; Merlivat, L2; Beaumont, L3; Danguy, T3; Guillot, A3; Repecaud, M4; Grossteffan, E5; Bucciarelli, E6; Guillou, J6; Blain, S7; Treguer, P6
1Station Biologique de Roscoff CNRS-UPMC, FRANCE;
2LOCEAN, Université Pierre et Marie Curie, Paris, FRANCE;
3Division Technique INSU-CNRS, FRANCE;
4IFREMER, Centre de Brest, FRANCE;
5UMS 3113 CNRS-UBO, Institut Universitaire Européen de la Mer (IUEM), Brest, FRANCE;
6UMR 6539 CNRS-UBO, IUEM, Brest, FRANCE;
7UMR 7621 CNRS-UPMC, Observatoire Océanologique de Banyuls sur Mer, FRANCE

Long-term monitoring of the marine carbon chemical species is necessary to assess the chemical and biological modifications occurring in the coastal ocean in a high CO2 World. Coastal marine ecosystems are directly impacted by human activities and are crossing a threshold of changing from their pre-industrial state, during which ocean margins are widely viewed as heterotrophic and a CO2 source, to a current or future state as a CO2 sink. The CARbon Interface Ocean Atmosphere (CARIOCA) sensor allows for both long term and high frequency measurements of the partial pressure of CO2 (pCO2). The CARIOCA sensor is therefore an excellent tool for investigating the high variability and the evolution of pCO2 in coastal environments. Here we present high-frequency pCO2 data recorded for 6 years during the first deployment of a CARIOCA sensor on a MAREL buoy in the surface waters of a temperate coastal ecosystem, the Bay of Brest, which is impacted by both coastal and oceanic variability. High frequency measurements allowed for the quantification of the diurnal, tidal and seasonal variability in the assessment of the annual CO2 air-sea fluxes. The preliminary results indicate that biological activity is the main process controlling the pCO2 variability in surface waters on a seasonal time-scale. On a shorter scale, the tidal and diurnal cycle are shown to be responsible for high pCO2 variability. The 6 years of investigation revealed that the surface waters of the Bay were near equilibrium with the atmosphere and that the inter-annual variability was small.

 
The MOOSE network: a tool to observe the long-term carbon change in the NW Mediterranean Sea
Coppola, Laurent1; Mantoura, Fauzi1; Blain, Stephane2; Durrieu de Madron, Xavier3; Gorsky, Gaby4; Goyet, Catherine5; Heussner, Serge3; Ludwig, Wolfgang3; Queguiner, Bernard6; Raimbault, Patrick7; Sempere, Richard7; Tamburini, Christian7; Miquel, Juan-Carlos8
1OOV, CNRS-UPMC, FRANCE;
2OOB, CNRS-UPMC, FRANCE;
3CEFREM, FRANCE;
4LOV, CNRS, FRANCE;
5Universite Perpignan, FRANCE;
6LOPB-COM, CNRS, FRANCE;
7LMGEM-COM, CNRS, FRANCE;
8MEL-IAEA, MONACO

In the Mediterranean Sea, the global warming and of the anthropogenic activities have been identified as the main forcings on the marine environment. However, their impact towards the biogenic elements cycle as carbon is not well understood. In the next decade, the reduction of the dense water formation in the Mediterranean Sea will induce a higher stratification of surface waters, lower ventilation and consequently a decrease of nutrient supply conducting to a decrease of new production and carbon export. However, this process should counteract the predicted increase in new production and in carbon export due to the raising of nutrient terrestrial discharge. In the deep water, the consumption of O2 for the remineralisation could be reduced due to the decrease in carbon export but concomitantly the supply of O2 to the deep water could also be reduced. The net effect on the O2 level in the deep water is difficult to predict. Acidification is climbing fast since increased seawater temperatures due to global warming enhance the capture of carbon dioxide by the world ocean, leading to a gradual increase in acidity in recent year. This process may induce significant changes on structure community of the Mediterranean ecosystems. While rates of change in marine acidity are still unclear, scientists stress the need to promote ocean acidification and global warming-related studies in the Mediterranean region in order to better understand these processes and predict consequences. Towards this Mediterranean evolution, only few time series have been performed over long term to explore the real effects of the massive anthropogenic activities and climate change on the oceanic carbon cycle. In this context, a Mediterranean Ocean Observing System on Environment project (MOOSE) is in progress to set up as an interactive, distributed and integrated observatory system of the NW Mediterranean Sea to detect and identify long-term environmental anomalies. It will be based on a multi-sites system of continental-shelf and deep-sea fixed stations as well as Lagrangian platform network to observe the spatio-temporal variability of physical and biogeochemical processes as carbon sequestration and acidification. Such observation network offers also an ideal platform to study specific processes with high temporal resolution on seasonal scale (INSU Mediterranean Program in progress).

 
Variability in northern Adriatic pCO2
Turk, D1; Malacic , V1; DeGrandpre, M2; McGillis, WR3
1National Institute of Biology, Marine Biology Station, SLOVENIA;
2Department of Chemistry, The University of Montana, UNITED STATES;
3Lamont-Doherty Earth Observatory, Columbia University, UNITED STATES

Coastal marine regions such as the Northern Adriatic Sea are strongly influenced by changes in climate and may play an important role in biological productivity and the global air-sea CO2 flux. These regions serve as a link between carbon cycling on land and the ocean interior and because the carbon dynamics are not studied in many coastal regions, their role in the global carbon cycle is highly uncertain. To date, in-depth studies of carbon cycling in coastal waters have been mostly limited to coastal transects that provide interesting snapshots of carbon dynamics. No CO2 flux data are currently available in the Northern Adriatic.

The Northern Adriatic, being one of the most productive regions in the Mediterranean and affected by freshwater input, eutrophication and large changes of air-sea exchange during Bora high wind events, makes this region an excellent study site for investigations of air-sea interaction and changes in biology and carbon chemistry.

Here we present the first measurements of air and water CO2 flux in the Northern Adriatic. The aqueous CO2 was measured at the coastal oceanographic buoy VIDA, Slovenia using the SAMI-CO2 sensor during four deployments in spring and summer/fall 2007, and spring/summer and fall of 2008. CO2 measurements were combined with hydrological and biological observations to evaluate the processes that control carbon cycling in the region. The results indicate that the GOT was a net sink for atmospheric CO2. Although some of the interannual and seasonal variability in aqueous CO2 can be explained with changes in SST, our data also suggest a significant influence by fresh water input from rivers, biological production associated with high nutrient input, and gas exchange during high wind events.

 
Sampling frequencies necessary for coastal ocean observatories
Devol, Allan; Newton, Jan; Ruef, Wendi; Ruef, W.; Newton, J.
University of Washington, UNITED STATES

As part of the Northwest Association of Networked Ocean Observing Systems (NANOOS), a mooring is maintained in coastal waters of Washington State. The mooring takes full depth water-column profiles for temperature, salinity, oxygen, fluorescence, nitrate and currents every two hours. Additionally, 10-minute averages of the meteorological data atmospheric temperature, wind velocity, wind direction, relative humidity, and solar radiation are also collected. All data is telemetered back to a shore-based laboratory computer in real time. Analysis of data obtained from the mooring for the150 day growing season in 2006 are used to determine the frequency of sampling at this site necessary to characterize various parameters. High frequency variability is characteristic of the study site and the variability is caused by a combination of tidal advection of horizontal patchiness as well wind induced destabilization of the mixed layer. The analysis suggest that the following sampling frequencies necessary to resolve; (1) the mean air-water gas exchange - ~ every 4 hours, (2) the mean the mean diurnal oxygen change - a diurnal oxygen cycle every other day, (3) and the annual chlorophyll cycle, (a chlorophyll profile once a week).

 
Time-series observation for biogeochemistry in the Western Pacific Subarctic Gyre
Watanbe, S; Matsumoto, K; Kawakami, H; Wakita, M; Fujiki, T; Saino, T
Japan Agency for Marine-Earth Science and Technology, JAPAN

Based on the time-series observation for the biogeochemistry at station KNOT (44N/155E)@between 1998 and 2001, which was Japanese national project under an umbrella of Joint Global Ocean Flux Study (JGOFS), it was verified that the North Pacific Western Subarctic Gyre (WSG) has large seasonal variability in nutrients, pCO2, primary productivity and particulate organic carbon flux, and time-series observation is very important in order to quantify carbon cycle in the ocean and air-sea exchange of CO2 by, especially, the biological activity (biological pump). Since 2001, time-series observation has been conducted at station K2 (47N/160E) by using the new mooring systems and research vessel. Our mooring system consists of various automatic sensor or samplers such as an optical sensor package (BLOOMS), a water sampler (RAS) and sediment traps deployed at multiple layers. Time-series observation of optical field and nutrients at ` 35 m by BLOOMS and RAS, respectively, revealed that phytoplankton increases and nutrients, especially silicate, decreases largely between late June and early July. During this time, increase of fluxes of particulate organic carbon and biogenic opal at ` 150 m was observed by sediment trap. It is indicative of that primary produced or assimilated organic carbon is transported quickly to the ocean interior. Multiple sediment traps from 150 m to 5000 m revealed that 1) biogenic materials are transported vertically without significant lateral transport, 2) sinking velocity of particles increases with depth, and 3) biogenic opal plays an important role in organic carbon transport. Seasonal observation of primary productivity, nutrients and natural radionuclide (thorium 234) by research vessel has also revealed that new production, export flux and export ratio are higher than those in other oceans, indicating that the biological pump at station K2 is very efficient for uptake of atmospheric CO2. On the other hand, long-term increase of dissolved inorganic carbon following increase of atmospheric CO2 has been observed at station K2. It is noted that increase rate of atmospheric pCO2 (pCO2(air)) in winter was higher than that of sea surface pCO2 (pCO2(sea)) in winter. Though pCO2(sea) in winter has been higher than pCO2(air) in winter until now, it is predicted that pCO2(sea) will be higher than pCO2(air) all year round after the middle 21 century. It is indicative of possibility that the ocean acidification will be accelerated after that period and ocean ecosystem will change in the WSG. In order to predict change in the biological pump and its feedback to the global environment, time-series observation should be continued with a new mooring system (optical sensor package including FRRF supported by underwater winch) at not only station K2, but also a new station located in the Western Pacific Subtropical Gyre as a counterpart of station K2.

 
SIBER: Sustained Indian Ocean Biogeochemical and Ecological Research
Hood, Raleigh R.
University of Maryland Center for Environmental Science, UNITED STATES

Historically the Indian Ocean has received relatively little attention from the oceanographic community and therefore remains substantially under-sampled compared to the Atlantic and Pacific Oceans. This situation is compounded by the Indian Ocean being a dynamically complex and highly variable system under monsoonal influence, which causes circulation features that are unusual in many respects. Comprehension of how biogeochemical and ecological processes respond to this dynamic physical environment has only partially been achieved and is fundamentally hampered by our current sampling deficiencies. Specific questions and hypotheses have emerged from recent studies that have yet to be tested, such as the potential role of zooplankton grazing versus iron limitation in controlling phytoplankton production in the Arabian Sea. Furthermore, the Indian Ocean is a globally important denitrification zone and it also appears to be a region where N2 fixation rates are significant. However, there are still large uncertainties in the rate estimates for both dentrification and N2 fixation so the role of the Indian Ocean in the global nitrogen budget has not yet been determined. The Indian Ocean is also warming rapidly, but the impacts of this warming on the biota, carbon uptake, and nitrogen cycling are unquantified. The increasing population density and rapid economic growth of the countries surrounding the Bay of Bengal and eastern Arabian Sea make these regions’ coastal environments particularly vulnerable to both this warming trend and to other anthropogenic influences. These anthropogenic effects might also impact the huge myctophid stocks in the Arabian Sea, but the time-space variability and the biogeochemical and ecological role of these fish are poorly quantified, as are the linkages between climate fluctuations and equatorial tuna migrations. The potential influences of climate variability and change on fisheries resources and their socio-economic ramifications need to be explored. Deployment of coastal and open-ocean observing systems in the Indian Ocean have created new opportunities for carrying out biogeochemical and ecological research. International research efforts should be motivated to exploit these opportunities for addressing these (and many other) pressing research questions.

 
Long-term observation of deep-sea benthic activities in Sagami Bay, central Japan
Kitazato, H.; Fujikura, K.; Kitazato, H.
Institute of Biogeosciences, JAMSTEC, JAPAN

Sagami Bay locates at the central Japan facing to the Pacific Ocean. Deep trough, called Sagami Trough, that show more than 1500 m deep lines at the central part of the Bay. Sagami Trough is convergent plate boundary between North American Plate and Philippine Sea Plate. Epicenter of huge earthquakes and active submarine volcanoes are located at the western part of the Bay. A lot of cold seepages with Calyptogena-clam colonies are distributed in the bay. JAMSTEC has long been monitoring crustal movement at the deep-sea floor. There is a long-term deep-sea observatory at the Off Hatsushima Island site at the western part of the bay. Since 1993, JAMSTEC continuously monitor benthic activities at the permanent observatory. We could pile up time-series video records and environmental dataset. Through these dataset we can trace environmental changes at continental slope regions and also watch how deep-sea benthic organisms actively dwell at deep-sea floor in relation to environmental changes. We also keep permanent deep-sea station at central Sagami Bay for monitoring long-term changes in population ecology of deep-sea meiofauna since 1991. Using these dataset, we can evaluate deep-sea environmental changes and responses of deep-sea organisms against environmental changes. We believe that human impact has already started to affect even at deep-sea floor. We propose to continue monitoring of deep-sea environments and organisms in Sagami Bay with several innovative approaches. Continual environmental monitoring through cable network at deep-sea observatory of the Off Hatsushima Island site, frequent ROV and AUV observational dives are strong tools for getting deep-sea data in Sagami Bay.

 
Long-term Biogeochemical Time-Series from the Porcupine Abyssal Plain Deep Ocean Observatory, North East Atlantic
Larkin, K.1; Lampitt, R.S.2; Billett, D.S.M.2; Hartman, S.E.2; Pebody, C.2; Pagnani, M.2; Gooday, A.J.2
1National Oceanography Centre, UNITED KINGDOM;
2National Oceanography Centre Southampton, UNITED KINGDOM

We present a suite of multidisciplinary biogeochemical data measured in situ at the Porcupine Abyssal Plain (PAP) fixed point observatory in the North East Atlantic (49°N, 16.5°W) over the past 20 years. The observations cover the entire water column and the seafloor beneath (4800 m). Data include autonomous measurements of temperature and salinity (to 1000 m), biogeochemical data at 30 m (including nitrate, chlorophyll and CO2) and deep ocean studies from benthic time-lapse photography and deep sediment traps. Future developments of the PAP site will be presented in a European and international context including contributions to EuroSITES, an EU FP7 project to integrate European deep ocean observatories and OceanSITES a worldwide system of deep water reference stations.

 
Monitoring pH of Seawater in the Adriatic Sea. Results From a Regional Observing Effort.
Luchetta, Anna1; Cantoni, Carolina1; Catalano, Giulio1; Civitarese, Giuseppe2; Celio, Massimo3
1C.N.R. ISMAR, ITALY;
2I.N.O.G.S., ITALY;
3ARPA FVG, ITALY

 
Dissolved Carbon Dioxide, Nutrients and Oxygen in the Adriatic Sea. A Regional Observing Effort.
Luchetta, Anna1; Cantoni, CArolina1; Catalano, Giulio1; Cozzi, Stefano1; Civitarese , Giuseppe2
1C.N.R. ISMAR, ITALY;
2I.N.O.G.S., ITALY

Increasing knowledge of the biogeochemistry of the Mediterranean Sea has been reputed important on global scale, since this "semi-enclosed" sea can be considered as a model for many open-ocean processes, including carbon cycling (Marty J.C., 2002). In particular, dissolved carbon dioxide content of seawater over an area, where anthropogenic influence is high due to proximity of industrialized zones, is expected to give rapid response to the climate change. Mediterranean basin can be therefore regarded as a key region very sensitive to the climate variability. In this frame the Adriatic Sea can play a quite relevant role for entire Eastern Mediterranean area, being site of dense water formation in winter and being able to sustain the most relevant primary production of entire region. This can provide further information about the sequestration of atmospheric CO2 through the Continental Shelf Pump mechanism, as proposed by Tsunogai (1999). The North Adriatic basin, in particular, is supposed to act a major role within the mechanism.

Despite of the increasing numbers of studies, there's still lack of good quality datasets regarding the inorganic carbon system in seawater over the region (Medar group 2002-MEDATLAS/2002 database), necessary to asses and monitor it . We present here data concerning the in situ fCO2, inorganic nutrients and dissolved oxygen collected over the whole Adriatic Sea during one cruise (February 2008) and new preliminary results of two time series (just started in 2008) from two key areas of the basin: the former in the Gulf of Trieste (the northermost of Med area, on monthly sampling), the latter in the Southern Adriatic pit (on seasonal sampling).

In situ fCO2 values have been calculated, according to Lewis & Wallace (1998), from experimental determinations of the pH (spectrophotometric method, as reported by Dickson in: DOE, 2007) and of the total alkalinity (potentiometric titration, precision of ± 1.0 µm/kgsw) For what concerns the wide shallow shelf region of northern Adriatic basin, fCO2 values provide an interesting winter snapshot of the CO2 dissolved in seawater. T/S data indicate February 2008 was characterized by the formation of very dense water (ot>29.3 kg/m3) at mesoscale; the water column was cold, homogeneous, well mixed and ventilated (AOU < 0 ) down to bottom, it was still rich of DIN (1.00-7.00 µM) and SiO2 (1.20-5.33 µM) while primary production had not yet started, except than in a very shallow coastal station. Our surface values (228.7 First results from the monthly time series carried out since July 2008 in the middle of the Gulf of Trieste (25 m depth), evidenced a seasonal variability of surface fCO2 controlled by both physical and biological parameters. In August 2008, even if production processes dominated the surface layer (Apparent Oxygen Utilization = -41.2 µM), the high water temperature (26.5°C) decreased CO2 solubility (fCO2 428 µatm) and the system acted as a CO2 source (Δ pCO2 = 63 µatm). During fall remineralization processes prevailed and surface fCO2 reached the higest value (462 µatm, September 2008). Only in Janury 2009, the weak biologial activity (AOU≈ 0) and the temperature decrease, lead the gulf to act as a CO2 sink (fCO2 ≈ 320 µatm, Δ pCO2 = -45 µatm).

Also in the southern Adriatic pit data have been collected in seasonal time series (September 2007-october 2008). In situ fCO2 have been calculated, for assessing vertical distributions (0-1200 m) and the seasonal variations. In surface waters (0-100 m) variations were wider (360–420 µatm) than in deeper layers. They depended clearly on the season and were controlled either by physical or biological processes: the highest values (≈ 400 µatm) were observed in winter (because of mixing with deeper layer, allowed by deep convection), the lowest (<320 µatm) in late spring through late summer (when biological activity was high).

 
NOAA Coral Reef Ecosystem Integrated Observing System (CREIOS): A Collaborative Ecosystem-Based Observing System
Morgan, J.A.1; Eakin, C.M.2; Brainard, R.E.3; Collins, D.W.4; Hendee, J.C.5; Monaco, M.E.6; Andrews, K.D.1
1NOAA Coral Reef Conservation Program, UNITED STATES;
2NOAA Coral Reef Watch, UNITED STATES;
3NOAA Coral Reef Ecosystem Division, UNITED STATES;
4NOAA Coral Reef Information System, UNITED STATES;
5NOAA Coral Health and Monitoring Program, UNITED STATES;
6NOAA Center for Coastal Monitoring and Assessment, UNITED STATES

The U.S. National Oceanic and Atmospheric Administration (NOAA) Coral Reef Conservation Program (CRCP) Coral Reef Ecosystem Integrated Observing System (CREIOS) conducts mapping and monitoring of coral reefs, their biota, and their environments in U.S. coral jurisdictions, uninhabited U.S. flag islands, and the Freely Associated States. CREIOS is a multi-agency effort by NOAA scientists in partnership with, on a jurisdictional-to-regional basis, Federal, State, Territory, Commonwealth, and local coastal management agencies, universities, non-governmental organizations, and international entities. CREIOS provides an ecosystem-based component to U.S. regional coastal ocean observing systems. The partnership approach is developing a CREIOS structure that will creatively and adaptively address managers' needs for scientifically-sound data, information products, and decision support tools that are both consistent and customized, allowing for regional-to-global analyses while also meeting local agencies' requirements. The CREIOS goal is to understand the condition of coral reef ecosystems in order to assist stakeholders in making ecosystem-based management decisions to conserve coral reef resources. Reef mapping and benthic habitat characterization provide a detailed picture of the physical and biological structure of coral reef communities, while periodic biological, physical, and chemical monitoring provide direct field observations of the condition of critical reef ecosystems, and continuous automated monitoring (in situ instrumentation and satellite-based) provides key environmental factors affecting reef condition. Mapping and monitoring activities are integrated to accurately document the status and changes in the habitats, depth ranges, geomorphologic zones, and reef types present in coral reef environments. All of the integrated mapping and monitoring studies are conducted in consultation with local natural resource management institutions and also through CRCP's coral reef ecosystem monitoring grants to State, Territory, and Commonwealth partners. CREIOS data and integrated information products provide support for a variety of management actions, including Marine Protected Area design and evaluation, and assessing the impacts of overfishing, land-based sources of pollution, and climate change. CREIOS products are accessible through the NOAA Coral Reef Information System (CoRIS).

 
Evaluation of MODIS bio-optical algorithms in the Arctic waters
Palanisamy, Shanmugam1; Tiwari, Surya Prakash1; Yu-Hwan , Ahn2; Joo-Hyung, Ryu2; Jeong-Eon, Moon2
1Indian Institute of Technology Madras, INDIA;
2Korea Ocean Research & Development Institute, KOREA, REPUBLIC OF

A data set containing chlorophyll-a (Chl-a), absorption coefficients of colored dissolved organic matter (aCDOM) and phytoplankton (aph) and remote sensing reflectances collected from field measurements in coincidence with MODIS observations during summer 2007 and 2008 was used to evaluate the performance of several standard bio-optical algorithms in the Artic Sea, where the Chl-a concentration varied from 0.01 to 5.0 mg m-3, aCDOM at 400 nm from 0.01 to 1 m-1, and aph at 400 nm from 0.005 to 5 m-1. Comparison of MODIS-observed remote sensing reflectances with in situ measurements showed good correlation at regional level, but with significant overestimation at 412nm and 443nm and underestimation at 551nm and 667nm wave bands. It was traced that higher MODIS remote sensing reflectances were likely caused by sub-pixel/adjacent effects of the ice cover in the region and improbable negative remote sensing reflectances in the blue bands by sub-pixel cloud contamination and known atmospheric correction failure in high latitude waters. All the MODIS pigment algorithms examined showed a systematic and significant overestimation particularly in low chlorophyll regimes, whereas MODIS_CZCS_Chl and MODIS_DAAC-v4_Chl algorithms yielded lower mean bias (MNB) and RMS errors than other algorithms. The performance of MODIS_OC3_Chl, MODIS_DC_Chl (Default case), and MODIS_DC_case-2_Chl (Default case) were however found relatively satisfactory than that of MODIS_case2_Chl and MODIS_case-1_Chl algorithms in these waters. The algorithms for estimating the absorption coefficients of CDOM and phytoplankton showed the worst performance among all the algorithms examined, with MNB and RMS error of 10.5% and 55.66% for aCDOM and 130% and 638% for aph. This suggests the apparent problems of the standard bio-optical algorithms and that new approaches for ocean colour algorithms are required in the high latitude Arctic Sea. The analysis also reveals that the atmospheric correction currently in use for MODIS usually fails to retrieve upwelling radiances emerging from the Arctic Sea and the cloud detection algorithm neglects to mask the contaminated pixels by clouds.

 
A COMPARATIVE AnaLYSIS OF CLIMATIC VARIABILITY and its impact on the ABROLHOS REGION (BA, BRASIL) CORAL BLEACHING
Pereira, Augusto A1; Wainer, Ilana1; Pezzi, Luciano2
1University of Sao Paulo, BRAZIL;
2INPE - National Institute for Space Research, BRAZIL

The Abrolhos bank region shelters one of the biggest and more complex biologic systems of the South Atlantic. Yet, this region of great ecologic, economic and social value hasn't been suficiently studied and it´s physical and biologic aspects hasn´t been described and interpreted in detail. There are few studies about the climatological variability of the Abrolhos bank despite the growing attention with respect to global warming impacts.This work, using meteorologic and oceanographic data aims to better understand this region with respect to climate parameters and establish, when possible, connections to the coral bleaching events. This will contribute to the evaluation and management of antropogenic impacts of the Abrolhos bank.

 
Phytoplankton Community and Trace Gas Studies from the Pride of Bilbao
Smythe-Wright, Denise1; Boswell, Stephen. M2
1National Oceanography Centre, UNITED KINGDOM;
2National Oceanography Centre, Southampton, UNITED KINGDOM

Primary production by plants and algae forms the base of all ecosystem processes. In addition, the oceans and their margins are home to a wide range of micro and macroalgae that are known to produce halogenated trace gases through their metabolic processes. Once in the atmosphere, these gases provide mechanisms by which chlorine, bromine and iodine compounds reach the stratosphere and are involved in the catalytic destruction of ozone. Many of these gases also have the ability to contribute to global warming, while some appear to instigate the production of cloud condensation nuclei that may help mitigate it. Studies have shown that biological gas release is not solely related to one species or taxa. It is more likely to be controlled by community structure and/or environmental conditions. Therefore, to understand and manage marine ecosystems and further our knowledge of trace gas release it is vital to monitor changes in phytoplankton community structure seasonally, inter-annually and on decadal timescales. In turn this will help us better understand how phytoplankton released gases might force or mitigate climate change. To this end, we have developed automated systems for the collection of biological samples and the analysis of halogenated trace gases for deployment on the Pride of Bilbao ferry. The biological sampler is a robotic system collecting samples for plant pigment analysis and taxonomic counting by microscopy and flow cytometry. The trace gas instrument is a membrane-inlet purge and trap system coupled to a GC-MS. Both systems take samples from the ship’s seawater intake. The systems work alongside a standard “Ferrybox system’ which logs temperature, salinity fluorescence and oxygen and sometimes includes a CO2 measuring system. The novelty of this work is the long time series of integrated, simultaneous measurements. The community structure work will form part of the new EU programme PROTOOL and the concept will be taken forward within the SCOR/IAPSO* working group Ocean Scope. * Scientific Committee on Ocean Research/International Association for the Physical Sciences of the Ocean.

 
Biophysical Moorings on the Eastern Bering Sea Shelf: 15 Years of Observations
Stabeno, Phyllis1; Napp, Jeff2; Whitledge, Terry3; Moore, Dennis1; Mordy, Calvin1
1NOAA Pacific Marine Environmental Laboratory, UNITED STATES;
2NOAA Alaska Fisheries Science Center, UNITED STATES;
3University of Alaska at Fairbanks, UNITED STATES

The southeastern Bering Sea shelf is one of the world's most productive shelf regions . This high subarctic sea is characterized by high biological productivity and the seasonal presence of sea ice. In the last decade, global temperatures have reached some of the highest levels recorded in recent history and projections of future temperature suggest that the greatest rates of change will be at high latitudes. A series of biophysical moorings have been deployed on the broad eastern Bering shelf at four sites . The southern most mooring is at ≈56.9°N and the northern site is at 62°N. At each site, ocean temperature, salinity, nitrate, oxygen, chlorophyll fluorescence and currents are measured. In addition, listening devices for marine mammals are also deployed at each site. At the southern site, instruments that measure zooplankton biovolume provide important information on temporal variability of zooplankton. These biophysical moorings, coupled with shipboard measurements, are used to understand how this ecosystem is changing under the influence climate variability.

 
Semi-automated classification of zooplankton by the ZooScan system: a network approach.
Stemmann, Lars1; Ohman, MD2; Picheral, M3; Gasparini, S1; Pesant, S4; Gorsky, G3
1University Pierre et Marie Curie, FRANCE;
2Scripps Institution of Oceanography, UNITED STATES;
3CNRS-LOV, FRANCE;
4MARUM, GERMANY

Using zooplankton data for ecological or modelling studies in global analysis requires homogeneous datasets. The ZooScan (www.zooscan.com) is a laboratory instrument that, in conjunction with free ZooProcess and Plankton Identifier software, forms an integrated analysis system for acquisition and classification of digital zooplankton images from preserved zooplankton samples. Digitized objects are detected, enumerated, measured, and classified. A semi-automatic approach is presented here where automated classification of images is followed by manual validation, which allows rapid and accurate classification of zooplankton and abiotic objects. The ZooScan system also provides an efficient mean to reconstruct plankton size spectra from taxonomically well-characterized zooplankton samples. In addition, it permits digital archiving of images in databases accessible to the scientific community and standardization of images from different ZooScans, allowing the construction of combined Learning sets and implementation of comparative studies. The analysis is non-destructive so the samples can be used for other purposes. Laboratory operation with aqueous samples is safe. Cooperative, networked activities over broad geographic scales can be enhanced by database management using, for example, the PANGAEA® data warehouse. The classification method proposed here allows a relatively detailed taxonomic characterization of zooplankton samples and provides a practical compromise between the fully automatic but less accurate and the accurate but time consuming manual classification of zooplankton for ecologically oriented studies or monitoring programs at regional and global scales through networks of users.

 
Physical-Biogeochemical Study Using a Profiling Float: Subsurface Primary Production in the Subtropical North Pacific
Suga, T1; Sukigara, C2; Saino, T3; Toyama, K2; Yanagimoto, D4; Hanawa, K2; Shikama, N3
1Tohoku University / JAMSTEC, JAPAN;
2Tohoku University, JAPAN;
3JAMSTEC, JAPAN;
4University of Tokyo, JAPAN

Profiling floats equipped with biogeochemical sensors present a unique opportunity to break new ground in exploring biogeochemical processes in conjunction with associated physical processes, which will contribute to a new generation of global ocean observing systems not only for physical fields but also biogeochemical fields and ecosystem. We present a recent result from physical-biogeochemical study using a profiling float equipped with biogeochemical sensors, which demonstrate its usefulness and potential.

Based on the extensive profiling float observation carried out as part of the Kuroshio Extension System Study (KESS), Qiu et al. (2006) reported large vertical eddy diffusivity (2 - 5 x10-4 m2s-1) near the upper boundary of Subtropical Mode Water (STMW). This large diffusivity possibly have an impact on subsurface redistribution of heat, nutrients and dissolved gas components, etc., in the subtropical ocean. On the other hand, recent measurement of turbulent kinetic energy dissipation rate by Mori et al. (2008) indicates much smaller vertical eddy diffusivity (10-7 - 10-5 m2s-1) over the whole depth range of STMW. However, the direct comparison between the estimation by Qiu et al. and that by Mori et al. is possibly inappropriate because the former is based on the PV change over a couple of months and the latter on the instantaneous turbulent measurements.

We carried out physical and biogeochemical observation to examine the vertical diffusivity near the top of STMW using a profiling float. The profiling float, which was equipped with a fluorometer and a dissolved oxygen sensor along with temperature and salinity sensors, was deployed in the STMW formation region and acquired quasi-Lagrangian, 5-day-interval time-series records from March to July in 2006. The time-series distribution of chl.a showed a sustained and sizable deep chlorophyll maximum just above the upper boundary of the STMW throughout early summer. Vertically integrated chlorophyll in this period was consistently ranging from 15-30 mgm-2, indicating sustained primary production and a continuous supply of nutrients ranging from 10-30 mgNm-2day-1. The time-series data indicate no appreciable sporadic events to supply nutrients and instead support, along with vertical profiles of nitrate obtained by ship-board measurements near the float, the large vertical diffusivity reported by Qiu et al. Since our estimation of vertical diffusivity is based on temporal evolution of primary production over several weeks, it is fairly consistent with their estimation.

 
An ocean monitoring program around Japan: a sensor for climate/environment variation of the western North Pacific
Tsuneo, Ono1; Tomowo, Watanabe2; Fisheries Research Agency, Monitoring team3
1Hokkaido National Fisheries Research Institute, Fisheries Research Agency, JAPAN;
2National Research Institute for Fisheries Science, Fisheries Research Agency, JAPAN;
3Fisheries Research Agency, JAPAN

The western North Pacific region in the vicinity of Japan Islands is the formation region of two large-scale water masses, North Pacific Intermediate Water (NPIW) and North Pacific Subtropical Mode Water (NPSTMW). These water masses play a key roll in the North Pacific shallow overturn system, and hence have strong relation to multidecadal-scale variation of oceanic environment observed in this basin (such as PDO). Japan Islands also face several marginal seas such as East China Sea and Japan Sea: Each of them has own long-term variation patterns independent to open western North Pacific, under the influence of large river systems and/or other coastal processes. These oceanic regions are also known as one of the most productive area in the world oceans, having definite importance in biogeochemical cycles and oceanic ecosystems including fisheries. Furthermore, now they are believed to be subject of ongoing changes caused by the global warming. To monitor these existing variations and predict future changes in the around-Japan oceanic regions, and to estimate their influence to biogeochemical and /or ecological processes including fisheries, Fisheries Research Agency had started a new set of hydrographic monitoring lines covering these oceanic regions from 2002. Shipboard surveys are operated basically seasonally on four lines in the around-Japan oceanic regions, and monitoring for hydrographic, biogeochemical and lower-trophic biological properties are observed in each line. A part of these monitoring lines have precedently established in 1988 and already have ~20 years time length, and retrospective studies using the pre-existing public dataset enable us to analyze more longer-term changes in these oceanic regions. So far, we have detected several long-term variations in these regions such as: 1)enhancement of surface stratification in subarctic Western North Pacific regions 2)subdecadal-scale reduction of winter surface nutrient concentrationsconcurrent with the surface stratification; and as the consequent, slight reduction of spring phytoplankton bloom in these regions. 3)High possibility for the advanced establishment of spring phytoplankton bloom after 1990s. Zooplankton biomass had both decreasing/increasing trend depending on oceanic regions and/or species, receiving combined affect of size-decreasing and advanced timing of spring blooms. 4)Surface stratification also occurs in East China Sea after 1960s to 1990s, owing to the enhanced load of Yangtze River concurrent to the changes of Chinese rainfall pattern.

 
SUMMER-TIME CO2 FLUXES AND CARBONATE SYSTEM BEHAVIOR IN THE MISSISSIPPI RIVER AND ORINOCO RIVER PLUMES
Wang, Zhaohui 'Aleck'1; Byrne, Robert H.2
1Woods Hole Oceanographic Institution, UNITED STATES;
2College of Marine Science, University of South Florida, UNITED STATES

High-resolution simultaneous spectrophotometric measurements of surface water pH, CO2 fugacity (fCO2), and total dissolved inorganic carbon (DIC) were obtained in July 2005 and September 2006 in the Mississippi River Plume (MRP) and the Orinoco River Plume (MRP) using a recently developed underway system, Multi-parameter Inorganic Carbon Analyzer (MICA). Traditional Niskin bottle samples of DIC and pH at depth were also collected and analyzed using the MICA system. The resulting data were analyzed to compare and contrast the CO2 fluxes and carbonate system behavior of the two river plumes under summer conditions. The surface water within the MRP shows a strong atmospheric CO2 sink (-4.9 ~ -7.7 mmol C m-2 d-1), while oligotrophic waters of the Gulf of Mexico were a CO2 source (1.3 ~ 2.9 mmol C m-2 d-1). The CO2 sink of the ORP is much less significant (-0.7 ~ -1.1 mmol C m-2 d-1), and the adjacent surface water of the Caribbean Sea was approximately in equilibrium with the atmosphere. The carbonate system inside the MRP exhibits patchiness (strong temporal and spatial variation). Such behavior is much less significant for the ORP, where both DIC and TAlk show strong conservative mixing. This study confirms that the two large river plums constitute carbon sinks under summer conditions. However, the strength of the sinks in these two coastal systems differs significantly due to both natural and anthropogenic influences.

 
JMA New Ship-based Observation for Climate/Carbon in the Western North Pacific
Kitamura, Yoshiteru
Japan Meteorological Agency, JAPAN

The Japan Meteorological Agency (JMA) has been conducting ship-based hydrographic observation along repeat sections for over 40 years in the western North Pacific, including the meridional section of 137E, to monitor interannual and decadal variability of the ocean circulation and water mass property. Since 1990s, the carbon observation such as total dissolved inorganic carbon (DIC) and a partial pressure of CO2 in near-surface seawater has been also conducted.

CLIVAR/Carbon and JMA results in the Pacific indicate that the various components of Pacific shallow meridional overturning circulation are subjected to climate change, and playing an important role in transporting the anthropogenic CO2 from the surface into the intermediate depths of the Pacific Ocean. However, to reduce the uncertainty in the anthropogenic CO2 uptake, it is needed to monitor the distribution of DIC and related biogeochemical parameters with higher spatial/vertical resolution. Furthermore, high frequency sampling could be effective to reduce the biases in high latitudes where property concentrations/inventories are affected by short-term climate variations through water mass formation, and in the western boundary region where the basin-scale dynamic response signals are accumulated.

JMA is planning a new ship-based observation which consists of the WHP-spec observation and routine observation to reinforce the international cooperation for monitoring and research on the oceanic CO2 uptake. The WHP-spec observation provides data with high-quality and high spatial and vertical resolution covering over the full water column every 4-5 years. It contains revisits of the WOCE P09 and P13. The semiannual/seasonal routine observation is conducted along meridional and zonal lines in the western North Pacific and seas adjacent to Japan. The routine observation would contribute to calibration of Argo sensor as well. JMA will start to implement the new plan in 2010.

 
The VECTOR Project: A Challenge for the Italian Marine Science Community
Zambianchi, E.1; Corselli, C.2; and the VECTOR group,3
1CoNISMa - Parthenope University, ITALY;
2CoNISMa and Milano-Bicocca University, ITALY;
3ITALY

V.E.C.T.O.R. (Vulnerability of the Italian coastal area and marine Ecosystems to Climate changes and Their rOlein the Mediterranean caRboncycles) is an overarching project which is seeing the joint effort of a very large portion of the Italian research community involved in coastal and marine sciences.

The project studies the most significant impacts of climate change on the Mediterranean marine environment and the role of this basin on the planetary CO2 cycle.

Its overall objectives are the assessment of the mechanisms related to the CO2 sequestration in the Italian seas, the evaluation of the role of the Mediterranean Sea on the planetary CO2 cycle, the assessment of the vulnerability of costal areas and of the effects of climate change on biodiversity.

Its main scientific sub-objectives can be summarized as follows: defining the role of the Mediterranean ecosystem in establishing sources and sinks of CO2; improving the understanding of the biogeochemical and carbon cycles; defining the sensitivity of the Mediterranean ecosystem to global change; predicting the ocean behavior in the CO2 cycle for the next 200 years; providing data on the effectiveness of the Italian seas in carbon sequestration, to be used in the international negotiations.

The project is in its third year of activity; so far, 21 cruises have been carried out in the framework of VECTOR, for a total of more than 150 days at sea. In this poster, we briefly report on the devised methodologies and discuss a choice of preliminary results obtained within the different workpackages, which have been characterized by a very strong interaction among different groups and institutions, as well as among different disciplines, with a special focus on dynamical and sedimentary processes, biogeochemical cycles and biodiversity, in different key areas of the Italian seas and of the Mediterranean basin.

 
Application of liquid waveguide to shipboard underway and in situ low-level nutrient measurements in seawater
Zhang, Jia-Zhong/J-Z
AOML/NOAA, UNITED STATES

Colorimetry is the conventional method for measuring nutrients in seawater. Recent applications of liquid waveguide long-path capillary flow cells to the colorimetric analysis have enhanced the sensitivity of nutrient detection by orders of magnitude. A nanomolar level of nitrate, nitrite, ammonium, phosphate, silicate and iron can be detected in oligotrophic waters. Such enhancement of sensitivity has been achieved by incorporation of liquid waveguide with a variety of automated analytical systems, including the gas-segmented continuous flow analysis(a method used in the nutrient autoanalyzers), flow injection analysis(FIA), and sequential injection analysis(SIA). Recent advances in application of liquid waveguide technology to nutrient analysis will be summarized and its potential for shipboard underway and in situ low-level nutrient measurements in seawater will be discussed.