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Oceanography

Oceanography encompasses many diverse disciplines, relating to the physical, chemical and biological processes which occur in the Earth’s oceans. Stable isotope analysis provides a powerful means to trace these processes, both modern and ancient; palaeoceangraphy uses oxygen stable isotope signatures of materials preserved in ice cores or sediments to elucidate the history of sea-surface or deep sea temperatures. Stable isotopes of oxygen and hydrogen can also reveal the hydrology of oceanic waters, tracing the movement and circulation of waters, evaporitic processes, and meteorological influences on local, regional or global scales.

Nutrient cycling and ecology of the world’s oceans is also of interest; carbon, nitrogen and sulfur stable isotopes are powerful tools which may be deployed to trace algal activity, elucidate food chain structures within surface or benthic communities, and trace fluxes of nutrients throughout the seasons. Stable isotope analysis is particularly useful for exploring the unusual frontiers of deep hydrothermal systems, where unusual chemosynthetic organisms are the lynchpins of the communities which thrive under those extreme conditions.

Oceanography publications using our instrumentation

Our customers use our instruments to do some amazing research in the oceanography application field. To show you how they perform their research and how they use our IRMS instruments, we have collected a range of peer-reviewed publications which cite our products. You can find the citations below and then follow the links to the publishing journal should you wish to download the publication.

If you would like to investigate our available citations in more detail, or email the citation list to yourself or your colleagues then take a look at our full citation database.

83 results:

Moon jellyfish, Aurelia aurita, in the Gulf of Gdansk: threatening predator or not?
BOREAL ENVIRONMENT RESEARCH (2016)
Dominika Bruli, Marcelina Zi, Stella Mudrak-cegio, Maciej Wo

The seasonal population dynamics and feeding preferences of the moon jellyfish, Aurelia aurita, in the Gulf of Gdansk (southern Baltic Sea) were investigated. Medusae were present in the water column from June to November, with maximum occurrence in August and September. The medusa bell diameter and weight increased during the study period reached maximum values in October. The relationship between bell diameter and wet weight was strong. No ephyrae were observed during the study period. Gastric content analysis revealed that the medusae fed mainly on copepods and cladocerans. Rotifers that dominated the water column throughout the study period were not found in the jellyfish guts, but the stable isotope signature indicated that they could have been a significant source of derived carbon. Low numbers of plankton prey and the lack of fish larvae in A. aurita guts suggest that the jellyfish is of minor relevance as a predator and competitor in the Gulf of Gdansk

Solar-, monsoon- and Kuroshio-influenced thermocline depth and sea surface salinity in the southern Okinawa Trough during the past 17,300 years
Geo-Marine Letters (2016)
Libo Wang, Jun Li, Jingtao Zhao, Helong Wei, Bangqi Hu, Yanguang Dou, Zhilei Sun, Liang Zou, Fenglong Bai

Factors influencing millennial-scale variability in the thermocline depth (vertical mixing) and sea surface salinity (SSS) of the southern Okinawa Trough (OT) during the past 17,300 years were investigated based on foraminifer oxygen isotope records of the surface dweller Globigerinoides ruber sensu stricto and the thermocline dweller Pulleniatina obliquiloculata in the AMS 14C dated OKT-3 core. The thermocline depth is influenced by surface thermal buoyancy (heat) flux, in turn controlled by the annual mean insolation at 30°N and the strength of the East Asian winter monsoon (EAWM). Strong insolation and weak EAWM tend to increase buoyancy gain (decrease buoyancy loss), corresponding to shallow thermocline depths, and vice versa. Regional SSS is influenced by the global ice volume, the Kuroshio Current (KC), and vertical mixing. A deep thermocline coincides with a high SSS because strong vertical mixing brings more, saltier subsurface KC water to the surface, and vice versa. Local SSS (excluding the global ice volume effect) became lower in the northern OT than in the southern OT after ~9.2 ka, implying that Changjiang diluted water had stronger influence in the northern sector. SSS show no major changes during the Bølling/Allerød and Younger Dryas events, probably because the KC disturbed the North Atlantic signals. This argues against earlier interpretations of sea surface temperature records of this core. Wavelet and spectral analyses of the Δδ18OP-G (δ18O of P. obliquiloculata minus G. ruber s.s.) and δ18Olocal records display 1,540-, 1,480-, 1,050-, 860-, 640-, and 630-year periods. These are consistent with published evidence of a pervasive periodicity of 1,500 years in global climate as well as EAWM and KC signatures, and a fundamental solar periodicity of 1,000 years and intermediary derived periodicity of 700 years.
Tags: oxygen , geol , ocea , mulitcarb

Exploring Accumulation Rates of Shell Deposits Through Seasonality Data
Journal of Archaeological Method and Theory (2016)
Niklas Hausmann, Matthew Meredith-Williams

Shell middens are often analysed as the result of short- or long-term depositional activities. In order to confidently interpret such deposits, it is necessary to have accurate estimations of shell accumulation rates, most commonly produced by radiocarbon dates. This paper introduces the application of seasonality data as a temporal measurement of short-term shell deposition. This gives access to an additional estimate of shell accumulation rates, which work on a shorter timescale than can be analysed through radiocarbon dating. We focus on shell deposits on the Farasan Islands, Saudi Arabia, which comprise over 3000 shell midden sites dating to the mid-Holocene (6500–4500 calBP). One site (JW1727) was chosen to (1) explore the potential of seasonality data to reconstruct accumulation rates, (2) analyse the intensity of exploitation and (3) assess the visibility of short-term shellfish deposits. Stable oxygen isotope values (δ18O) were obtained from the marine gastropod Conomurex fasciatus (Born 1778), representing 72 % of the shell weight of JW1727, to reconstruct season of capture. Seasonality data was grouped by their spatial distribution, which allowed successive episodes of deposition within a stratigraphic sequence to be connected. This allowed us to make an estimation of exploited shell meat of ∼200 kg over a 7-month period (∼400 shells/day). We argue that excavation methods and low resolution stratigraphic data cause imprecision in the seasonality data and the low visibility of rapidly accumulated shell deposits. Also, an increase of analysed shells per layer is key to understanding the seasonal brickwork of more middens in the future
Tags: carbon , oxygen , geol , ocea , clim , mulitcarb

Lithostratigraphic analysis of a new stromatolite-thrombolite reef from across the rise of atmospheric oxygen in the Paleoproterozoic Turee Creek Group, Western Australia.
Geobiology (2016)
E Barlow, M J Van Kranendonk, K E Yamaguchi, M Ikehara, A Lepland

This study describes a previously undocumented dolomitic stromatolite-thrombolite reef complex deposited within the upper part (Kazput Formation) of the c. 2.4-2.3 Ga Turee Creek Group, Western Australia, across the rise of atmospheric oxygen. Confused by some as representing a faulted slice of the younger c. 1.8 Ga Duck Creek Dolomite, this study describes the setting and lithostratigraphy of the 350-m-thick complex and shows how it differs from its near neighbour. The Kazput reef complex is preserved along 15 km of continuous exposure on the east limb of a faulted, north-west-plunging syncline and consists of 5 recognisable facies associations (A-E), which form two part regressions and one transgression. The oldest facies association (A) is characterised by thinly bedded dololutite-dolarenite, with local domical stromatolites. Association B consists of interbedded columnar and stratiform stromatolites deposited under relatively shallow-water conditions. Association C comprises tightly packed columnar and club-shaped stromatolites deposited under continuously deepening conditions. Clotted (thrombolite-like) microbialite, in units up to 40 m thick, dominates Association D, whereas Association E contains bedded dololutite and dolarenite, and some thinly bedded ironstone, shale and black chert units. Carbon and oxygen isotope stratigraphy reveals a narrow range in both δ(13) Ccarb values, from -0.22 to 0.97‰ (VPDB: average = 0.68‰), and δ(18) O values, from -14.8 to -10.3‰ (VPDB), within the range of elevated fluid temperatures, likely reflecting some isotopic exchange. The Kazput Formation stromatolite-thrombolite reef complex contains features of younger Paleoproterozoic carbonate reefs, yet is 300-500 Ma older than previously described Proterozoic examples worldwide. Significantly, the microbial fabrics are clearly distinct from Archean stromatolitic marine carbonate reefs by way of containing the first appearance of clotted microbialite and large columnar stromatolites with complex branching arrangements. Such structures denote a more complex morphological expression of growth than previously recorded in the geological record and may link to the rise of atmospheric oxygen.
Tags: carbon , oxygen , geol , ocea , clim , mulitcarb

Processes governing the stable isotope composition of water in the St. Lawrence river system, Canada.
Isotopes in environmental and health studies (2016)
Eric Rosa, Claude Hillaire-Marcel, Jean-François Hélie, Alexandre Myre

Linkages between δ(18)O-δ(2)H and hydrological processes have been investigated from isotopic time series recorded in the St. Lawrence River basin. Three stations were monitored from 1997 to 2008. They include the Ottawa River, the St. Lawrence River main channel at Montreal and the fluvial estuary. All sites depict seasonal isotopic cycles characterized by heavy isotope depletions during the snowmelt period and heavy isotope enrichments throughout the ice-free period. The data define δ(2)H-δ(18)O regression lines falling below the meteoric water line. In the Ottawa River, calculations suggest that approximately 8 % of the total inflow to the basin is lost through evaporation. In the St. Lawrence River main channel, seasonal isotopic fluctuations most likely reflect hydrological processes occurring within the Great Lakes and mixing with tributaries located downstream. In the St. Lawrence River fluvial estuary, isotopic data allow partitioning streamflow components and suggest that the recorded seasonal variations mainly respond to mixing processes.

Coupling of marine and continental oxygen isotope records during the Eocene-Oligocene transition
Geological Society of America Bulletin (2016)
Nathan D. Sheldon, Stephen T. Grimes, Jerry J. Hooker, Margaret E. Collinson, Melanie J. Bugler, Michael T. Hren, Gregory D. Price, Paul A. Sutton

While marine records of the Eocene-Oligocene transition indicate a generally coherent response to global cooling and the growth of continental ice on Antarctica, continental records indicate substantial spatial variability. Marine Eocene-Oligocene transition records are marked by an ~+1.1{per thousand} foraminiferal {delta}18O shift, but continental records rarely record the same geochemical signature, making both correlation and linking of causal mechanisms between marine and continental records challenging. Here, a new high-resolution continental {delta}18O record, derived from the freshwater gill-breathing gastropod Viviparus lentus, is presented from the Hampshire Basin, UK. The Solent Group records marine incursions and has an established magnetostratigraphy, making it possible to correlate the succession directly with marine records. The V. lentus {delta}18O record indicates a penecontemporaneous, higher-magnitude shift (>+1.4{per thousand}) than marine records, which reflects both cooling and a source moisture compositional shift consistent with the growth of Antarctic ice. When combined with "clumped" isotope measurements from the same succession, about half of the isotopic shift can be attributed to cooling and about half to source moisture change, proportions similar to marine foraminiferal records. Thus, the new record indicates strong hydrological cycle connections between marine and marginal continental environments during the Eocene-Oligocene transition not observed in continental interior records.

Distributions of highly branched isoprenoid alkenes and other algal lipids in surface waters from East Antarctica : further insights for biomarker-based paleo sea-ice reconstruction
Organic Geochemistry (2016)
Lukas Smik, Simon T Belt, Jan L Lieser, Leanne K Armand, Amy Leventer

The occurrence and variable abundance of certain di- and tri-unsaturated C25 highly branched isoprenoid (HBI) biomarkers in Antarctic marine sediments has previously been proposed as a possible proxy measure of paleo sea-ice extent in the Southern Ocean. In the current study, we obtained 47 near-surface (ca. 0–10 m) water samples taken from locations in East Antarctica with different sea ice settings and analysed them for their HBI, sterol and fatty acid content. Sampling locations ranged from the permanently open-ocean zone (POOZ), with no seasonal sea-ice cover, the near-shore summer sea ice zone (SIZ), where sea ice remains long into the summer melt season, and the marginal ice zone (MIZ), located between the POOZ and the SIZ, and with a highly variable latitudinal sea-ice edge throughout the season. A di-unsaturated C25 HBI (diene II) was only identified in surface waters from the MIZ and the SIZ, consistent with a sea-ice diatom origin for this biomarker. In contrast, a tri-unsaturated C25 HBI (triene III) was detected in all samples from the POOZ, the MIZ and the SIZ, and with a stable isotopic composition (δ13C = –35 ± 1.5‰) consistent with a phytoplankton source. The highest concentrations of diene II and triene III were in samples from the SIZ and the MIZ, respectively, thus providing further insights into the sea-ice conditions likely favourable for their production and how their relative abundances (the II/III ratio) in underlying sediments might be better interpreted for paleo sea-ice reconstruction. In this respect, relatively high II/III might be a good indicator of extended (into summer) seasonal sea-ice cover, while lower II/III may provide a better indicator of the MIZ. However, the observation of highly variable II/III within the polynya setting of the SIZ may also have 4 significant impacts on sedimentary values. Distributions of diatom sterols and fatty acids were also variable between the three sampling zones, but these were not as distinctive as those observed for the HBIs
Tags: carbon , ocea , clim , gaschrom

ENSO variability around 2000 years ago recorded by Tridacna gigas δ18O from the South China Sea
Quaternary International (2016)
Hong Yan, Chengcheng Liu, Wenchao Zhang, Ming Li, Xufeng Zheng, Gangjian Wei, Louhua Xie, Wenfeng Deng, Liguang Sun

El Niño–Southern Oscillation (ENSO) is the most important mode of interannual changes in global climate. The knowledge of ENSO variability in different mean climate conditions is essential for us to understand the ENSO mechanism and predict its future trend in a warming world. Here we present a 50-year-long, monthly resolved oxygen isotope record, obtained from a 14C dated (AD 50 ± 40) fossil giant clam, Tridacna gigas, located on Dongdao Island, South China Sea, where the interannual climate anomaly is dominated by ENSO variations. We developed a quantitative method to extract the ENSO events from the regional Sea Surface Temperature (SST) and oxygen isotope records. And then, the ENSO variations about 2000 years ago, located in the so called Roman Warm Period, was calculated from the oxygen isotope series of fossil T. gigas. Our quantitative record shows that ENSO variance in Roman times was similar to the instrumental times, with a total of 11 El Niño events and 12 La Niña events within 50 years.
Tags: carbon , oxygen , ocea , clim , mulitcarb

Assessing the trophic position of two sharks from the open waters of the southeastern Pacific Ocean.
Latin American Journal of Aquatic Research (2016)
Sebastian A.; Cornejo Klarian

Stable isotope analyses for shortfin mako (Isurus oxyrinchus) and blue sharks (Prionace glauca) were conducted to assess their trophic position in two periods of time (before 1980 and after 2000) in the Southeastern Pacific waters (SEP). Both sharks showed that their trophic position decreased over time (P < 0.05). Many factors could be involved in this change such as dietary shifts, prey availability, or indirect fishing effects in SEP waters

Photoacclimatory Responses of Zostera marina in the Intertidal and Subtidal Zones.
PloS one (2016)
Sang Rul Park, Sangil Kim, Young Kyun Kim, Chang-Keun Kang, Kun-Seop Lee

Photoacclimatory responses of the seagrass Zostera marina in the intertidal and subtidal zones were investigated by measuring chlorophyll a fluorescence parameters, photosynthetic pigments, leaf δ13C values, and shoot morphology in two bay systems. Intertidal plants had higher carotenoid concentrations than subtidal plants to avoid photodamage under excess light conditions during the day. The maximum relative electron transport rate (rETRmax) and minimum saturation irradiance (Ek) of the intertidal plants were higher than those of the subtidal plants, whereas photosynthetic efficiency (α) and maximum quantum yield (Fv/Fm) were higher in subtidal plants. The intertidal plants also had significantly greater Stern-Volmer non-photochemical quenching (NPQ) than that of the subtidal plants. These results suggest that the subtidal plants photoacclimated to use limited light more efficiently, and the intertidal plants exhibited photosynthetic responses to minimize photodamage at excess irradiance. The δ13C values of leaf tissues were more negative in the intertidal plants than those in the subtidal plants, suggesting that the intertidal plants used atmospheric or dissolved CO2 for photosynthesis during emersion. Effective quantum yield (ΔF/Fm´) in the intertidal plants decreased more slowly after emersion than that in the subtidal plants, indicating higher desiccation tolerance of the intertidal plants. The intertidal plants also recovered more rapidly from desiccation damage than the subtidal plants, suggesting photosynthetic adaptation to desiccation stress. The photosynthetic plasticity of Z. marina in response to variable environmental conditions most likely allows this species to occur in the intertidal and subtidal zones.