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LC–NMR combines the advantage of the outstanding separation power of liquid chromatography (LC) and the superior structural elucidating capability of nuclear magnetic resonance (NMR). NMR has proved that it is a standout detector for LC by providing maximum structural information about plant originated extracts particularly in its isolating ability of isomeric (same molecular formula) and/or isobaric (same molecular weight) compounds as compared to other detectors. The present review provides an overview of the LC–NMR developmental trends and its application in natural products analysis. The different LC–NMR operational modes are described, as well as how technical improvements assist in establishing this powerful technique as an important analytical tool in the analysis of complex plant-derived compounds. On-flow, stop-flow and loop-storage modes, as well as the new offline mode LC–SPE–NMR and capLC-NMR configurations that avoid the ingestion of expensive deuterated solvents throughout the experiment are mentioned. Utilization of cryogenic probe and microprobe technologies which are the other important promising approaches for guaranteeing the sensitivity issues are also described. Concluding remarks and future outlooks are also discussed.

Increasing our understanding of spatial patterns of plant secondary chemistry variation may help us understand the mechanisms that underlie plant invasions involving species which exhibit chemical phenotypic variation. We analysed qualitative and quantitative variation in the essential oil terpenes produced by Thymus vulgaris L. (thyme) plants inside and at the edge of thyme-invaded plant communities on north- and south-facing slopes at ten sites across Central Otago, New Zealand. We tested the hypotheses that (1) there are foliar terpene composition quantitative and qualitative differences between the inside and edge of thyme-invaded communities and that these differences vary between north- and south-facing slopes and (2) that environmental variables affect the quantity and quality of thyme essential oil composition. Terpene concentrations were determined using ethanol extraction and GC FID/MS. Environmental data were collected from inside, at the edge and outside of thyme stands. We used multivariate statistical analysis to test differences in foliar terpene composition and linear modelling to investigate the effects of environmental variables on terpene composition. We found no evidence of a link between aspect- and invasion edge-related patterns of variation of thyme’s essential oil chemistry. Site-related differences for aspect and position in thyme stands indicated that thyme’s terpene production may be modulated by environmental factors such as soil moisture, clay, carbon, silt, sand, colloid, N and NH4+. The role of thyme’s novel chemistry in the processes that underlie the spatial patterns of thyme’s successful invasion is modulated by environmental factors.

Hydrogen isotope ratios (δ2H) have become a tool for food traceability and authentication of agricultural products. The principle is that the isotopic composition of the produce is influenced by environmental and biological factors and hence exhibits a spatial differentiation of δ2H. This study investigates the variation in δ2H values of New Zealand milk, both in the bulk powder and individual fatty acids extracted from milk samples from dairy factories across New Zealand. Multivariate statistical analyses were used to test for relationships between δ2H of bulk milk powder, milk fatty acid and geographical location. Milk powder samples from different regions of New Zealand were found to exhibit patterns in isotopic composition similar to the corresponding regional precipitation associated with their origin. A model of δ2H in precipitation was developed based on measurements between 2007 and 2010 at 51 stations across New Zealand (Frew and Van Hale, 2011). The model uses multiple linear regressions to predict daily δ2H from 2 geographic and 5 rain-weighted climate variables from the 5 × 5 km New Zealand Virtual Climate Station Network (VCSN). To approximate collection radius for a drying facility the modelled values were aggregated within a 50 km radius of each dairy factory and compared to observed δ2H values of precipitation and bulk milk powder. Daily δ2H predictions for the period from August to December for the area surrounding the sample collection sites were highly correlated with the δ2H values of bulk milk powder. Therefore the δ2H value of milk fatty acids demonstrates promise as a tool for determining the provenance of milk powders and products where milk powder is an ingredient. Separation of milk powder origin to geographic sub-regions within New Zealand was achieved. Hydrogen isotope measurements could be used to complement traditional tracking systems in verifying point of origin.

To determine whether fatty acid (FA) profiles are a useful biomarker to trace the flow of material in a coastal food web, we fed the sandhopper Bellor - chestia quoyana specific seaweed diets, each with a contrasting FA profile including Durvillaea antarctica (Phaeophyta), Ecklonia radiata (Phaeophyta) or Ulva sp. (Chlorophyta). We then compared changes in FA composition in relation to diet for this sandhopper. After 12 d, sandhoppers from each treatment had distinct FA profiles, particularly with respect to polyunsaturated FAs (PUFAs); however, increases in specific FAs did not relate to those FAs that were abundant in their diet. For example, sandhoppers fed PUFA-deficient Ulva sp. exhibited a relative increase in PUFAs. The E. radiata and Ulva sp. diets both caused significant shifts in sandhopper FA composition over the course of the experiment. In order to follow the assimilation of carbon and FAs, sandhoppers were fed natural or 13C-enhanced E. radiata or Ulva sp., and changes to the δ13C of individual FAs were measured over time. Turnover of the most abundant FAs, 16:0 and 18:1ω9, was higher for sandhoppers fed E. radiata than for those fed Ulva sp. Comparisons between bulk tissue δ13C and δ13C of individual FAs were consistent with sandhoppers modifying the turnover rate of FA in response to diet. These findings suggest that there is no consistent relationship between the FA compositions of green and brown seaweeds and that of the sandhopper B. quoyana. We caution that community-level application of FAs as a dietary biomarker tool must be accompanied by controlled experiments incorporating key species of relevance.

Compound-specific isotope analysis (CSIA) is fast becoming an important tool to provide chemical evidence in a forensic investigation. Attempts to trace environmental oil spills were successful where isotopic values were particularly distinct. However, difficulties arise when a large dataset is analyzed and the isotopic differences between samples are subtle. Thus, this study intends to demonstrate any linkages between diesel fuels in a large number of datasets where subtlety in the isotopic values is accentuated by the near single-point source of origin. Diesel fuels were obtained from various locations in the South Island of New Zealand. Aliquots of these samples were diluted with n-pentane and subsequently analyzed with gas chromatography-isotope ratio mass spectrometry (GC-IRMS) for carbon and hydrogen isotope values. The data obtained were subjected to principal component analysis (PCA) and hierarchical clustering. A wide range of δ13C and δ2H values were determined for the ubiquitous alkane...

Lipids are very important for human health and milk is a rich dietary source of lipids. In this study, the lipid content in three types of milk (goat, soy and bovine) were determined by using UPLC-Q-Exactive Orbitrap Mass Spectrometry. A total of 13 classes of lipids (including Cer, SM, LPC, PC, PE, DG, TG, PA, PG, PI, PS, LPE, FA) were measured. Moreover, lipid profiles differed significantly between the different milk types. Soymilk is rich in phospholipids including PC, PE, PS, PG, while goat milk is rich in medium chain triglycerides (MCT), USFA, ω-6 FA and ω-3 FA, especially EPA and DHA. Furthermore, a PLS model was established for differentiation of milk types based on the lipid profiles. A total of 14 lipids were identified as biomarkers for differentiation of milk types, thus providing a basis for milk authentication and detection of adulteration.

Predictive understanding of precipitation δ2H and δ18O in New Zealand faces unique challenges, including high spatial variability in precipitation amounts, alternation between subtropical and sub-Antarctic precipitation sources, and a compressed latitudinal range of 34 to 47 °S. To map the precipitation isotope ratios across New Zealand, three years of integrated monthly precipitation samples were acquired from >50 stations. Conventional mean-annual precipitation δ2H and δ18O maps were produced by regressions using geographic and annual climate variables. Incomplete data and short-term variation in climate and precipitation sources limited the utility of this approach. We overcome these difficulties by calculating precipitation-weighted monthly climate parameters using national 5-km-gridded daily climate data. This data plus geographic variables were regressed to predict δ2H, δ18O, and d-excess at all sites. The procedure yields statistically-valid predictions of the isotope composition of precipitation (long-term average root mean square error (RMSE) for δ18O = 0.6 ‰; δ2H = 5.5 ‰); and monthly RMSE δ18O = 1.9 ‰, δ2H = 16 ‰. This approach has substantial benefits for studies that require the isotope composition of precipitation during specific time intervals, and may be further improved by comparison to daily and event-based precipitation samples as well as the use of back-trajectory calculations.

Sea ice growth rates near ice shelves are influenced by ocean-ice shelf interactions. Sea ice growth rates and ocean observations from McMurdo Sound, Antarctica in 1999 and 2000 are presented in this paper. Growth rate measurements were made for an individual platelet crystal through video camera observations. It was found that the crystal grew in discontinuous, episodic bursts at rates of the order of 10 − 6 m s − 1 . Sea water 0.15 m beneath the lower ice surface was measured to be supercooled by 0.01 K. Indications are that supercooling was continuous over the period of episodic platelet ice crystal growth and the growth bursts are attributed to the influence of variable currents. Growth rates for bulk sea ice (i.e., columnar and incorporated platelet ice) and heat fluxes were derived from ice temperature measurements. The growth rates for bulk sea ice were found to be of the order of 10 − 7 m s − 1 , an order of magnitude less than the rates for the individual platelet ice crystal. The residual of the energy balance suggested that a negative oceanic heat flux (i.e., heat transport down into the ocean) occurred, in addition to conduction of heat up into the atmosphere. Both salinity-based growth rate models and an oxygen isotope-based growth rate model (Eicken, 1998) were found to under-predict growth rates compared to those derived from ice temperature measurements. In addition, inverting the growth rates predicted by the models and integrating over the depth of the core failed to accurately predict the date of initial sea ice formation. Modifications are proposed to the models for sea ice formation occurring near ice shelves, where platelet ice formation is likely. Differences between bulk and individual platelet ice crystal growth rates are discussed with reference to heat fluxes, oceanic flows and the Eicken (1998) model.

New Zealand sedimentary sequences are important repositories of southern temperate palaeoenvironmental data, as may be interpreted from biogenic chemical signals preserved in marine microfossils. Calibration curves for Mg/Ca ratios versus water temperatures were established using modern benthic foraminifera, Notorotalia and Cibicides . Notorotalia is a long-ranged endemic benthic genus with a good record in shelf sediments, while Cibicides allows comparisons with similar studies elsewhere. The resulting correlations were T (°C) = ln(Mg/Ca [mmol/mol] / 1.64) × 10.89 for Cibicides spp., and T (°C) = ln(Mg/Ca [mmol/mol] / 0.44) × 5.71 for Notorotalia spp. Well-preserved Early Miocene Notorotalia and Cibicides were collected for paired Mg/Ca and δ 18 O analysis from a 3.6 m section of the Mount Harris Formation spanning an estimated 60 ka and dating from about 17.7 Ma ( Globoconella zealandica zone, roughly middle Burdigalian, Early Miocene) within the local Altonian Stage (15.9–18.7 Ma). Mg/Ca bottom-water palaeotemperature estimates from Cibicides and Notorotalia gave concordant results: 13.3 ± 1.0 °C for Notorotalia spinosa , 15.5 ± 3.0 °C for Cibicides spp. Estimates of oxygen isotopic composition for Altonian sea water (δ 18 O palaeo-sw ) were − 0.4 ± 0.4‰, suggesting the presence of small ice sheets on Antarctica. The method used to generate such results has far reaching implications for reconstructing δ 18 O palaeo-sw , and should allow Antarctic ice volume history to be finely resolved from New Zealand sequences.

Cadmium, a highly toxic metal, exhibits a nutrient-type profile in the oceans that is closely correlated to that of the major nutrients phosphate and nitrate. Despite its complexity, the relationship between cadmium and phosphate has been used to infer historic phosphate utilization and biological controls on oceanic CO 2 concentrations. Cadmium isotopes offer the potential to constrain the mechanisms controlling cadmium cycling in the oceans, reducing uncertainty associated with the cadmium paleonutrient proxy. Using techniques in double spiking and MC-ICPMS, we report seasonal Cd isotopic and concentration data along with major nutrients and other essential trace metal (Fe, Zn, and Co) concentrations from subantarctic surface waters. We show, for the first time, a 50-fold seasonal decrease in dissolved cadmium concentrations in subantarctic waters that is due to biological uptake. However, this drawdown in Cd is decoupled from phosphate and shows no coincident shift in cadmium isotopic composition. These data, along with the preferential removal of Cd from surface waters relative to Zn, imply that cadmium is supply-limited to phytoplankton and may have a more significant biological role in these low Zn subantarctic surface waters than in regions with higher Zn concentrations.

In laboratory experiments we examined the interplay of light and iron availability on the intracellular iron concentrations, specific growth rates, and photosynthetic physiology of Southern (S.) Ocean diatoms (Eucampia antarctica and Proboscia inermis) and the haptophyte Phaeocystis antarctica. Intracellular iron concentrations and iron : carbon (Fe : C) molar ratios increased with decreasing irradiance in temperate coastal (Thalassiosira weissflogii) and oceanic (Thalassiosira oceanica) diatoms, in support of the well-established antagonistic iron–light relationship. In contrast, S. Ocean species required lower cellular iron concentrations and Fe : C ratios than temperate diatoms to grow at comparable rates, and their iron requirements decreased or remained relatively constant with decreasing light. These results suggest that the current paradigm that low light increases algal cellular iron requirements (supplied through ‘‘biodilution’’) is not applicable to S. Ocean phytoplankton. Although iron use efficiencies decreased at sub-saturating light in all species, these reductions were due primarily to lower growth rates, but not higher intracellular Fe : C ratios, in S. Ocean species. We propose that S. Ocean species have overcome the antagonistic iron–light relationship by increasing the size, rather than the number, of photosynthetic units under low irradiances, resulting in an acclimation strategy that does not increase their cellular iron requirements.

Sessile epifauna that excrete ammonium as a waste product are often closely associated with surfaces of macroalgae that are able to absorb and use ammonium for growth. This close association means that nitrogen provisioning from epifauna to host macroalgae is probable, but barriers to uptake, formed by epifaunal colonies, and the physiological status of colonised macroalgal tissue may limit the amount of ammonium absorbed by colonised macroalgae. Evidence for the movement of nitrogen from sessile epifauna into and around the giant kelp Macrocystis pyrifera was gathered using a 15N-enriched stable isotope tracer. Experiments in which 15N-labelled phytoplankton was fed to the epifaunal bryozoan Membranipora membranacea did not to find conclusive evidence for the flow of nitrogen released by bryozoan colonies into colonised M. pyrifera tissue. The low degree of transmission of 15N observed may be due to the barrier to nitrogen uptake that is formed by M. membranacea tissue and the low affinity for ammonium uptake by M. pyrifera blades during winter. M. membranacea is unlikely to provide significant benefits to host macroalgae via nitrogen provision in many situations, due to its sheet-forming habit and its absence during summer low-nitrogen periods. In situ incubations of M. pyrifera blades in 15N-enriched ammonium were used to determine if ammonium provided by epifaunal colonies could be taken up by mature blades tissue and exported to the stipe for long-distance transport to actively growing meristems. Uptake and export of labelled nitrogen from basal blades into the stipe was measured, and the potential for longdistance transport of nitrogen from older blades was confirmed. Active transport of nitrogen from older macro algal tissue colonised by epifauna such as hydroids could be an important mechanism allowing kelp with specialised long-distance solute transport systems to tolerate nitrogen limitation.

A combination of ground-penetrating radar surveys, physical sedimentology and ice composition measurements has been used to characterize ice and sediment accreted to the southern margin of the McMurdo Ice Shelf, Antarctica. The radar data and surface observations show that the ice-shelf margin consists of strongly layered debris-rich ice that contains marine sediment and fossils. A modified Rayleigh-based distillation system has been used to model the isotopic fractionation from sea water to ice in a closed system. The model of ice formation is consistent with formation during almost complete freezing of a sea-water reservoir. By contrast, ice on the upstream side of the grounding line has formed during the early stages of freezing in which a small fraction of the sea-water reservoir has frozen. The model results and the presence of delicate, well-preserved marine fossils are interpreted as evidence of anchor ice formation on the seabed, and rafting of glaciomarine sediment into the bottom of the ice shelf. We argue that repeated accretion of sea water and marine sediment has produced a stacked sequence of ice and glaciomarine debris that forms shore-parallel ice-cored moraines.

We report results of laboratory studies examining the effect of low levels of iron (Fe) availability on the intracellular Fe concentrations and specific growth rates in Southern Ocean diatoms (Fragilariopsis kerguelensis, Eucampia antarctica, Proboscia inermis, and Thalassiosira antarctica) and Phaeocystis antarctica. All species grew on Fe complexed to the siderophore desferrioxamine B (DFB). Concentrations of DFB up to 100-fold in excess of Fe were required to limit growth rates by $ 50%. Southern Ocean phytoplankton also grew on Fe complexed by $ 10-fold excess concentrations of the siderophores ferrichrome, enterobactin, or aerobactin, whereas the temperate coastal diatoms Thalassiosira weissflogii and Thalassiosira pseudonana did not. Intracellular Fe concentrations and Fe:C ratios of all Southern Ocean species were exceptionally low and decreased with decreasing Fe availability. However, large diatoms had significantly lower cell-volume–normalized Fe content and Fe:C ratios than Phaeocystis. Short-term Fe uptake and extracellular Fe(II) production measurements provided evidence that Phaeocystis possesses a reductive Fe transport pathway. Our findings demonstrate that the largediatom Fe requirements are at least 2-fold lower than currently reported for oceanic algal species and suggest that bioreduction may enable resident phytoplankton to directly use Fe bound to strong organic ligands.

Fossil bioapatite may yield biogeochemical signals of paleoenvironments captured by living organisms. Bioapatite may be diagenetically altered, however, with ions added or removed post-mortem; such change is typically assessed using destructive and demanding techniques. Here, Raman spectroscopy is used as a rapid and non-destructive way to identify significant diagenetic alteration of fossil bioapatite. We found spectral parameters of phosphate symmetric stretching (ν1-PO43−) to be very sensitive to variations in apatite chemistry, particularly with respect to common diagenetic components (CO32−, F−, Sr2+). The Raman spectral parameters were subsequently applied to a set of modern (biogenic) and geologic (magmatic) apatite samples as potential endmembers for diagenetic alteration. Raman spectra were also collected from enamel and dentin (respectively resistant vs. alteration-prone) of fossil teeth. Phosphate-oxygen isotopic values from the same enamel–dentin samples were used as an index of alteration and provided definition of Raman spectral parameters as relates to diagenetic alteration. Diagenetically altered samples were characterised by spectra with ν1-PO43− widths (at half maximum height) less than 13.0 cm− 1, and ν1-PO43− band positions greater than 964.7 cm− 1. Raman spectroscopy is shown to have potential as a tool for pre-screening fossil apatite samples before further analyses.

On Conch Reef, Florida Keys, USA, we examine relationships between temperature variability measured with a unique, high-resolution sensor network, and the abundance of benthic reef organisms and carbon, nitrogen and oxygen stable isotopic composition of two abundant macroalgal species. Visualization of spatial temperature anomalies mapped onto measured reef bathymetry reveals episodic thermal patchiness and persistent thermal features likely indicating meter scale variability in nutrient supply. These patterns result from the relatively shallow depths of the offshore thermocline and an active internal wave field creating a hydrographic structure conducive to interactions of an offshore, subthermocline nutrient pool with reef topography. The distribution of major benthic reef organism taxa, as well as the stable isotopic composition of C, N and O, from the macroalgae Dictyota menstrualis and Halimeda tuna are all highly variable on scales of less than 10 m and are not necessarily depth-dependent. Covariability between spatial patterns of the temperature minima, depth and d 13 Co fD. menstrualis and H. tuna suggest a role of oceanographic forcing in inorganic carbon acquisition in these species. Comparisons of the measured temperature with the predicted temperature based on d 18 O from H. tuna aragonite suggest a possible influence of low salinity water in the system and non-linear interactions between ambient conditions and calcification at fine temporal and spatial scales. These observations have implications for the interpretation of both contemporary and paleontologic reef environments where oceanographic forcing interacts with complex reef topography.

The Horse Range Formation is a structurally controlled late Early Cretaceous to early Late Cretaceous nonmarine unit in east Otago, South Island, New Zealand, containing immature lithic debris. Clasts are generally rounded, with only minor subangular material. The formation contains clasts derived from two principal basement sources: schist and greywacke. Schist debris is most abundant at the base of the described section, and this material is dominated (>60%) by quartz from the greenschist facies core of the Otago Schist belt. Conglomerates with >70% greywacke clasts constitute most of the upper part of the Horse Range Formation. These greywacke conglomerates have a matrix of sand derived mainly from schist. A 60 m thick wedge of quartz‐rich, locally carbonaceous sand occurs interlayered with greywacke conglomerates. The Horse Range Formation rests on sub‐greenschist facies semischist, which forms only a small proportion (

This paper examines the basal ice sequence of Rhone Glacier, a cold-based glacier in the McMurdo Dry Valleys, Antarctica, using isotopic and solute chemistry data. Three different ice facies are identified: englacial, amber and stratified. The englacial facies is clean, bubbly ice of meteoric origin and is underlain by an amber facies. Amber ice is a characteristic of cold alpine glaciers in the McMurdo Dry Valleys and is distinctive for its high solute concentrations and much higher strain rates compared with the overlying englacial ice and the underlying stratified ice. Analysis of the stratified facies reveals an isotopic signature indicative of melt then refreeze processes and it is most likely associated with apron entrainment at the margin. By contrast, the amber facies has a co-isotopic slope of 8 and plots on a meteoric waterline. The inclusion of impurities in the amber ice reveals prolonged contact with the bed, and its depleted isotopic signature is consistent with ice formed during a cooler period. Comparison of the basal sequence of Rhone Glacier with other cold-based glaciers in the McMurdo Dry Valleys reveals strong similarities between valley-side glaciers (e.g. Meserve and Rhone Glaciers), whereas valley-floor glacier basal sequences (e.g. Suess Glacier) are characterized by structurally complex amalgamations of ice and debris.

Landfill leachate comprises a complex mixture of contaminants many of which may have multiple sources in the environment confounding conventional techniques for apportioning sources. Compound specific isotope ratio mass spectrometry offers the potential to “fingerprint” compounds enabling discrimination to be made between different sources. This paper presents a rapid and highly reproducible method to prepare landfill leachate samples for compound specific isotope analysis. A suitable solid phase extraction (SPE) method was developed using artificial contaminant solutions, natural waters spiked with artificial contaminants (eucalyptol, dodecane, benzothiazole, dibutyl phthalate and naphthalene), and samples of landfill leachate. The elution of adsorbed compounds from the SPE cartridge was found to be the major cause of hydrogen and carbon isotope fractionation. Three different SPE cartridge types were tested: C18, Strata-X and ENV+. Fractionation of between 1‰ and 245‰ for hydrogen isotopes and 0–1.83‰ for carbon isotopes was observed. Part of the fractionation could be attributed to the different SPE cartridges but the major contribution was from the choice of the eluting solvent. Our results indicated hydroxylated styrene-divinylbenzene cartridges eluted with dichloromethane resulted in negligible hydrogen or carbon isotope fractionation for any of the tested organic compounds. The isotopic fractionation of hydrogen and/or carbon of most artificial contaminants were proportional to the efficiency with which they were extracted from water. Only naphthalene exhibited isotopic fractionation unrelated to its extraction efficiency but this fractionation was negligible. The comparative extraction of landfill leachate using SPE and LLE indicated SPE generally extracts slightly more of each compound from leachate than LLE. This relationship is stronger than for polar compounds. In addition, the δD composition of each compound prepared using SPE was with two standard deviations of the sample compound prepared using LLE, and the δ 13 C composition of each compound prepare using either method was mostly within two standard deviations.

Many coastal marine populations persist across gradients in benthic productivity. In the New Zealand fjords there is a sharp gradient in available biomass between the wave-washed outer coasts, dominated by kelps, and the quiescent inner fjords, where estuarine seaweeds and terrestrial inputs predominate. In Doubtful Sound we found significant variation in abundance of macroalgal groups, the grazing sea urchin Evechinus chloroticus and the detritivorous sea cucumber Stichopus mollis, and in δ 15 N and δ 13 C of the macroalgae and consumers among 5 study sites across this gradient. Analysis of δ 15 N and δ 13 C from tissue of the 2 consumers relative to the primary carbon source pools with a mass balance model indicated that diet was primarily influenced by composition and quality of macroalgal food, except at the innermost sites, where there was evidence for terrestrial inputs. These results demonstrate that it is important to resolve relative abundance of food sources and specific iso- topic variation to resolve spatial patterns in diet from stable isotope analysis across environmental gra- dients. Isotopic analysis of E. chloroticus stomach contents from the innermost sites provided strong evidence that terrestrial detritus was being assimilated via microbial recycling (δ 15 N, -5‰ and δ 13 C, -37 ‰). Differences in δ 13 C of stomach contents versus those of tissues provided a basis to measure as- similation. There was a strong correlation between this proxy for assimilation with growth parameters among study sites across the ecotone. This analysis indicates a strong bottom-up influence on vital rates of E. chloroticus within the fjord, with links to the source-sink structure of the population.

Biogenic isotopes of analytical interest may be stripped from bone during burial, reducing the utility of fossil specimens for paleobiological and paleoenvironmental reconstruction. Denudation of the bone lattice coupled with the addition of exotic ions can influence the Raman spectra of fossil bone. Modern bone samples (n = 43) were used to establish an unaltered bone standard, and a suite of synthetic apatite samples were produced to simulate the addition of various ions into the bone mineral lattice. Diagenetic alteration produces distinct spectral characters, providing qualifications for major ionic substitution, ionic heterogeneity, the abundance of structural carbonate, the presence of calcium carbonate and the presence of luminescent ions. Spectral indicators (proxies) provide the means of rapidly and nondestructively evaluating the degree of alteration and thus the analytical utility of fossil bones, potentially avoiding exhaustive and destructive analysis on finite material. Copyright © 2007 John Wiley & Sons, Ltd.

The influence of wave-exposure on the growth and erosion rates of Macrocystis pyrifera was determined in Paterson Inlet, Stewart Island, New Zealand, for each season of 2002. During autumn, following a period of low seawater nitrogen, sites that received significant amounts of oscil- latory flow from waves exhibited higher frond growth rates than at wave-sheltered sites. Blade and stipe growth rates at wave-exposed sites were at a yearly maximum during this period, and were 4.3 and 1.6 times higher respectively than at wave-sheltered sites where growth was at a yearly mini- mum. During this time C:N ratios and nitrogen concentrations of blade tissues indicated that the nitrogen status of frond apices, where the majority of growth occurs, was greater at wave-exposed sites than at wave-sheltered sites. During periods when kelp tissue nitrogen levels are low, but some inorganic nitrogen is available in the water column, oscillatory flow may enhance nutrient uptake by M. pyrifera by increasing the flux of nutrients into kelp canopies and by reducing the size of diffusion boundary layers at the kelp surface. Exposure to waves also modified the seasonal pattern of M. pyrifera growth by ameliorating the negative effect of low seawater nitrogen concentrations during summer and autumn. Blade and stipe growth was relatively steady at wave-exposed sites during the study period, while wave-sheltered sites had distinct seasonal patterns with low growth during summer and autumn, increasing through winter to spring maxima. In this system, water motion influences the growth rates of M. pyrifera only at specific times of year; when tissue nitrogen levels are low but some inorganic nitrogen is available in the water column.

We examined nitrogen (N) uptake in seven grassland streams lying in catchments along a gradient (0–84% )o f agricultural land use in New Zealand using a stable isotope (15N) addition of NH z to quantify whole-stream uptake rates and uptake by specific compartments within the streams. Whole-stream uptake of NH z ranged from 1.2 mmol N m22 min21 to 7.9 mmol N m22 min21 and showed no evidence of strong saturation of uptake with increasing NH z availability along the land use gradient. The relatively simple pattern of increasing N uptake along the gradient occurred despite substantial shifts in uptake among community members. Uptake of NH z by epilithic biofilms followed a subsidy–stress relationship, with highest uptake rates at intermediate levels of pastoral development and lowest uptake rates at high pastoral development. At high (.60%) pastoral development, reduced uptake by epilithon was compensated for by enhanced uptake by macrophytes. Compensatory uptake can play an important role in streams when community composition is reorganized by human activity.

Field surveys and laboratory experiments were used to investigate the influence of the physical environment on variability in d13C and d15N signatures of Ulva pertusa, an abundant macroalgae inhabiting the low salinity layer (LSL) of Doubtful Sound, a New Zealand fjord. Field surveys revealed significant spatial variability in d13C (218% to 212%) and d15 N( 0% to 6%). d13C was enriched at high irradiance sites and depleted at the fjord’s wave-exposed entrance. d15N signatures increased from 0% at the fjord head where freshwater influence is greatest to an oceanic signature of 6% at the fjord entrance. d15N also increased by up to 4% between 2-m depth and the LSL–seawater interface (4-m depth); this pattern was less pronounced near the ocean. During laboratory experiments, d13 Co fU. pertusa became significantly enriched under high levels of irradiance (.50 mmol quanta m22 s21). When exposed to high irradiance, increases in water motion rapidly depleted d13C signatures by as much as 5%. Variability in d 13 Co fU. pertusa in Doubtful Sound is largely a function of the light regime, which influences rates of photosynthesis and in turn the algae’s dependence on HCO 2 , an enriched source of carbon. However, increased water motion at the fjord entrance counteracts the influence of irradiance, leading to enhanced flux of CO2 and depleted d 13 C signatures. Variation in d 15 No fU. pertusa is less dependent on the physical environment and instead is driven by the source pool signature, which in turn varies between freshwater and marine sources of nitrogen.

Nitrous oxide (N2O) is a biogenic trace gas in the atmosphere having significant role in global climate change and stratospheric chemistry. Its concentration in the ambient air has increased to the current value of 325 ppbv from 275ppbv in last hundred years. Oceans account for 25-30 % of global N2O emissions. Tropical and coastal regions contributes to more than 50 % of oceanic emissions; however, the biogeochemical pathways leading to its formations are poorly constrained. Nitrification and denitrification dominates N2O production with their N2O source product varying with oxygen availability. This paper describes the dissolved nitrous oxide concentration and its changes with apparent oxygen utilisation (AOU) along the Northeast Arabian Sea waters during South West Monsoon. Stable isotopic study of N2O including d15Nbulk, d18O, d15Nα and its site preference (SP) which is the difference between d15N α and d15N β were also conducted for the first time in this oceanic regions. The N2O were highly concentrated at the surface as compared to the other oceanic waters especially in the upwelling regions and the concentration increased to a maximum value in the oxygen less bottom waters. From sea to air N2O flux measurements these water masses appeared as a source for N2O with an average flux of 0.001-0.5 Tg N2O per year. The N2O vs AOU and Nitrate relationship suggested the importance of nitrification in the formation of N2O. The dual isotopic signatures of d 15Nbulk-N2O and d 18O were suggestive of more than one mechanism responsible for production with a nitrification dominated pathway in N2O cycling. The d18O of O2 confirms that mostly N2O is derived through nitrification process through the oxidation of NH2OH/NO. The SP values confirmed the existence of nitrification and nitrifier denitrification throughout the stations along the depth. This results suggest the need for more detailed study in the Gulf waters from where the highest N2O emissions were reported in 1991 for the first time.

The Rise & Shine Shear Zone is a late metamorphic deformation zone developed in biotite zone Textural Zone 4 schist in Central Otago. The shear zone has been hydrothermally altered, with addition of gold associated with replacement of schist minerals by pyrite and arsenopyrite. Hydrothermal alteration of schist during mineralisation involved replacement of titanite by rutile, recrystallisation of metamorphic quartz, muscovite and chlorite, and addition of ankerite. Mineralised schist has abundant microshears that have developed parallel and subparallel to the pervasive schist foliation, and these microshears contain much of the hydrothermal sulfides and gold. Microshears have been deformed locally by upright syn‐mineralisation brittle reverse faults and angular folds that have a southerly axial trend. These more brittle deformation zones are confined to the Rise & Shine Shear Zone. Gold‐bearing veins and mineralised breccias, made up of quartz, albite, pyrite, arsenopyrite, calcite, and chlorite,...

Most seagrass community food‐web studies using stable isotopes have been carried out in subtidal habitats during one sampling event. We used C, N, and S stable isotopes to characterise the diet of the dominant macroinvertebrates found in intertidal Zostera capricorni and sandflat communities of southern New Zealand in late summer and winter. The range of a13C and a34S values for Z. capricorni was wide (>5‰), which highlights the importance of accounting for spatial and temporal variability in primary producer isotopic signatures. The range of a15N values for Z. capricorni was comparatively small (

The presence of the stoloniferous hydroid Obelia geniculata (L.) had no effect on the pigment concentration or nitrogen status of underlying blade tissue of the giant kelp Macrocystis pyrifera (L.) C. Agardh. The sheet-like colonies of the bryozoan Membranipora membranacea (L.) markedly reduced the pigment concentration of colonized blade tissue, but only during winter. Reductions in pigment concentration are most likely a result of damage to underlying tissue due to some factor related to the presence of bryozoan colonies on blade surfaces. Blade tissue colonized by M. membranacea also had higher δ15N signatures than surrounding bryozoan-free tissue, possibly indicating the provision of nitrogen to M. pyrifera by bryozoan colonies. Results show that seasonal changes in nitrogen and colony size can strongly modify the effect of epifauna on macroalgae they colonize. Unlike bryozoans, hydroid colonies provided no barrier to nitrogen uptake by colonized M. pyrifera tissue and enhanced ammonium uptake was observed for tissue colonized by O. geniculata during nitrogen limitation. Epifauna with stoloniferous growth forms such as hydroids are more likely to have benign or even mutualistic relationships with macroalgae they colonize than the sheet-like colonies of bryozoans.

Bacterially mediated methanogenesis in municipal solid waste landfills has been shown to cause an enrichment of carbon stable isotope ratios of dissolved inorganic carbon and hydrogen stable isotope ratios of water in landfill leachate. In the present study, we investigate the universality of this enrichment in leachate obtained from four diverse landfill sites in New Zealand. At each site, surface water samples upstream and downstream of landfills were analysed to examine the applicability of stable isotope ratios as a tool for monitoring leachate contamination in landfill-associated streams. The design of leachate collection systems, operational history, and landfill location appeared to strongly influence leachate isotopic values and the effectiveness of isotope ratios as an environmental monitoring tool for surface water.

Effects of feeding glucose on substrate metabolism during cycling were studied. Trained (60.0 ± 1.9 mL · kg−1 · min−1) males (N = 5) completed two 75 min, 80% VO2max trials: 125 g 13C-glucose (CHO); 13C-glucose tracer, 10 g (C). During warm-up (30 min 30% VO2max) 2 ⋅ 2 g 13C-glucose was given as bicarbonate pool primer. Breath samples and blood glucose were analyzed for 13C/ 12C with IRMS. Protein oxidation was estimated from urine and sweat urea. Indirect calorimetry (protein corrected) and 13C/ 12C enrichment in expired CO2 and blood glucose allowed exogenous (Gexo), endogenous (Gendo), muscle (Gmuscle), and liver glucose oxidation calculations. During exercise (75 min) in CHO versus C (respectively): protein oxidation was lower (6.8 ± 2.7, 18.8 ± 5.9 g; P = 0.01); Gendo was reduced (71.2 ± 3.8, 80.7 ± 5.7%; P = 0.01); Gmuscle was reduced (55.3 ± 6.1, 65.9 ± 6.0%; P = 0.01) compensated by increased Gexo (58.3 ± 2.1, 3.87 ± 0.85 g; P = 0.000002). Glucose ingestion during exercise can spare endogenous protein and carbohydrate, in fed cyclists, without gly-cogen depletion.

Streams are important sites of nutrient transport and transformation in the landscape but little is known about the way in which individual taxa or individual habitats (riffles and pools) influence nutrient dynamics within stream reaches. We used 5-week additions of a stable isotope (15NH4Cl) tracer to investigate nitrogen dynamics in pools and riffles of two New Zealand streams, one with native fish (Galaxias depressiceps) and the other with invasive brown trout (Salmo trutta). In New Zealand, brown trout initiate a trophic cascade leading to increased algal biomass that we predicted would lead to higher N uptake and retention. Uptake of NO3, but not ammonium, was greater in the trout stream. Rather than causing a large increase in N demand, trout may induce a reallocation of N uptake and retention among food web compartments in different habitats. The largest differences between streams were apparent in riffles, where most uptake and retention of N occurred. In the trout stream, uptake rate by epilithon in riffles was more than six times greater than uptake rates of any other compartment. In the Galaxias stream, several compartments in both habitats had similar uptake rates. Epilithon also accounted for a larger percentage of the 15N retained in the study reach in the trout stream (51%) than the Galaxias stream (34%). Our results show that an individual predatory taxon (in our case an invader) can influence N dynamics in streams but that the magnitude and location of the impact depend on a range of abiotic and biotic factors involved in N dynamics in streams.

Although direct links between habitat conversion and human activities are often apparent, their causal mechanisms may be less obvious. We identified historic salinity change, attributed to freshwater input from a hydroelectric power plant, as a potential mechanism of intertidal habitat conversion and severe local decline of the New Zealand littleneck clam (Austrovenus stutchburyi) in Doubtful Sound, New Zealand. Live clams were abundant at sites distant from the power plant with relatively unaltered salinity regimes, and were absent from the inner fjord near the power plant outflow. Remnant shells indicate past habitation by A. stutchburyi at inner fjord sites. Historic salinity conditions inferred from oxygen isotope ratios in shell carbonates confirm that salinity previously reached higher values in the inner fjord, and that A. stutchburyi probably has not inhabited that area since salinity was at pre-power-plant levels. A laboratory experiment showed that A. stutchburyi from Doubtful Sound have a high tolerance for low salinity conditions, but that hyposaline conditions become lethal after extended exposure (37-day LC50 = 2.5). In situ transplant experiments demonstrated that present salinity conditions in the inner reaches of Doubtful Sound are lethal to this species. Our findings suggest that the increased fresh- water input maintained by the power plant has converted the habitat in the inner reaches of Doubtful Sound to one with sustained low salinity unsuitable for the survival of A. stutchburyi.

During Refueling Outage 18 (RFO18, April 2011) Pilgrim Nuclear Power Station (PNPS) identified crack-like indications on the Steam Separator Lifting Lugs. A multi-disciplinary engineering effort was undertaken to determine the cause of the cracking and prepare the technical justification for long term operation of the lifting lugs. This approach focused on addressing the potential for future degradation due to the existing indications, and the resulting effects on the hardware and its function. A materials evaluation concluded that intergranular stress corrosion cracking (IGSCC), most likely associated with cold work present in the as-fabricated steam separator, was the cause of the indications found on the lifting lugs. To support long term operation of the lifting lugs at PNPS, a structural evaluation was completed using ANSI N14.6 and NUREG-0612 criteria with a conservative bounding configuration. Crack growth rates, based on BWRVIP-76 guidance of 5E-5 in/hr for length and 2.2E-5 in/hour for depth, were used in the analyses. The evaluation concluded that PNPS could continue with long term operation of the Steam Separator. Consistent with standard practice, a general heavy loads examination was performed in 2013 (RFO19), confirming no discernable changes. The general examination will be repeated in 2015 (RFO20), and an examination of the lifting lugs is planned for the 2017 Refueling Outage (RFO21) to confirm that the indication behavior is consistent with the evaluation results.

During the 13 day Southern Ocean Iron RE-lease Experiment (SOIREE), dissolved iron concentrations decreased rapidly following each of three iron-enrichments, but remained high (>1 nM, up to 80% as FeII) after the fourth and final enrichment on day 8. The former trend was mainly due to dilution (spreading of iron-fertilized waters) and particle scavenging. The latter may only be explained by a joint production-maintenance mechanism; photoreduction is the only candidate process able to produce sufficiently high FeII, but as such levels persisted overnight (8 hr dark period) —ten times the half—life for this species—a maintenance mechanism (complexation of FeII) is required, and is supported by evidence of increased ligand concentrations on day 12. The source of these ligands and their affinity for FeII is not known. This retention of iron probably permitted the longevity of this bloom raising fundamental questions about iron cycling in HNLC (High Nitrate Low Chlorophyll) Polar waters.

We have investigated the effect of iron supply and increased phytoplankton growth on the cycling of the macronutrients phosphate, nitrate and silicic acid as well as the micronutrients copper (Cu), nickel (Ni), zinc (Zn) and cadmium (Cd). Nutrient levels were measured in situ in an iron-induced phytoplankton bloom at 61°S 140°E in the Southern Ocean Iron Release experiment (SOIREE). Nutrient ratios upon arrival at the study site indicate that much of the seasonal phytoplankton productivity was by iron-limited diatoms growing at low mean light levels. The addition of iron (Fe) induced a bloom that led to a draw-down in the macronutrients in ratios consistent with the growth of diatoms under iron-replete conditions. None of the bioutilised trace metals Cu, Ni, Zn or Cd showed any indication of co-limitation, with Fe, of phytoplankton growth. Zn concentrations did not decrease by algal uptake as expected. Cd was partitioned to the particulate phase indicating consumption by the algae. Cd was preferentially utilised with respect to P with a α Cd/P =5.8. Interpretation of the Cd/Ca data from the sedimentary record using this higher induced α Cd/P value would imply even higher Southern Ocean surface water P during the last glacial maximum.

Dendritic crystals of platelet ice appear beneath the columnar land-fast sea ice of McMurdo Sound, Antarctica. These leaf-like crystals are frozen into place by the advancing columnar growth. The platelets most probably begin to appear during July although in some parts of the Sound they may not appear at all. In addition, the amount and extent of platelet ice within the Sound varies from year to year. Previous authors have suggested that the formation of platelet ice is linked to the presence of the nearby ice shelf. It is a matter of debate whether these platelets form at depth and then float upwards or whether they grow in slightly supercooled water at the ice/water interface. The phenomenon is similar to that observed in the Weddell Sea region, but previous authors have suggested the two regions may experience different processes. This paper presents the results of field-work conducted in McMurdo Sound in 1999. Ice-structure analysis, isotopic analysis and salinity and temperature measurements near the ice/water interface are presented. Freezing points are calculated, and the possible existence of supercooling is discussed in relation to existing conjectures about the origin of platelets.

The ratio of oxygen-18 to oxygen-16 (expressed as per mille deviations from Vienna Standard Mean Ocean Water, 18O) is reported for seawater samples collected from seven full-depth CTD casts in the northern North Atlantic between 20° and 41°W, 52° and 60°N. Water masses in the study region are distinguished by their 18O composition, as are the processes involved in their formation. The isotopically heaviest surface waters occur in the eastern region where values of 18O and salinity (S) lie on an evaporation–precipitation line with slope of 0.6 in 18O–S space. Surface isotopic values become progressively lighter to the west of the region due to the addition of 18O-depleted precipitation. This appears to be mainly the meteoric water outflow from the Arctic rather than local precipitation. Surface samples near the southwest of the survey area (close to the Charlie Gibbs Fracture Zone) show a deviation in 18O–S space from the precipitation mixing line due to the influence of sea ice meltwater. We speculate that this is the effect of the sea ice meltwater efflux from the Labrador Sea. Subpolar Mode Water (SPMW) is modified en route to the Labrador Sea where it forms Labrador Sea Water (LSW). LSW lies to the right (saline) side of the precipitation mixing line, indicating that there is a positive net sea ice formation from its source waters. We estimate that a sea ice deficit of ?250 km3 is incorporated annually into LSW. This ice forms further north from the Labrador Sea, but its effect is transferred to the Labrador Sea via, e.g. the East Greenland Current. East Greenland Current waters are relatively fresh due to dilution with a large amount of meteoric water, but also contain waters that have had a significant amount of sea ice formed from them. The Northeast Atlantic Deep Water (NEADW, 18O=0.22‰) and Northwest Atlantic Bottom Waters (NWABW, 18O=0.13‰) are isotopically distinct reflecting different formation and mixing processes. NEADW lies on the North Atlantic precipitation mixing line in 18O–salinity space, whereas NWABW lies between NEADW and LSW on 18O–salinity plots. The offset of NWABW relative to the North Atlantic precipitation mixing line is partially due to entrainment of LSW by the Denmark Strait overflow water during its overflow of the Denmark Strait sill. In the eastern basin, lower deep water (LDW, modified Antarctic bottom water) is identified as far north as 55°N. This LDW has 18O of 0.13‰, making it quite distinct from NEADW. It is also warmer than NWABW, despite having a similar isotopic composition to this latter water mass.

Changes in iron supply to oceanic plankton are thought to have a significant effect on concentrations of atmospheric carbon dioxide by altering rates of carbon sequestration, a theory known as the 'iron hypothesis'. For this reason, it is important to understand the response of pelagic biota to increased iron supply. Here we report the results of a mesoscale iron fertilization experiment in the polar Southern Ocean, where the potential to sequester iron-elevated algal carbon is probably greatest. Increased iron supply led to elevated phytoplankton biomass and rates of photosynthesis in surface waters, causing a large drawdown of carbon dioxide and macronutrients, and elevated dimethyl sulphide levels after 13 days. This drawdown was mostly due to the proliferation of diatom stocks. But downward export of biogenic carbon was not increased. Moreover, satellite observations of this massive bloom 30 days later, suggest that a sufficient proportion of the added iron was retained in surface waters. Our findings demonstrate that iron supply controls phytoplankton growth and community composition during summer in these polar Southern Ocean waters, but the fate of algal carbon remains unknown and depends on the interplay between the processes controlling export, remineralisation and timescales of water mass subduction.

Measurements of the ratio of stable isotopes of oxygen (18O and 16O) from samples collected on World Ocean Circulation Experiment sections SR1b (eastern Drake Passage) and A11 (Punta Arenas to Cape Town) are used, together with hydrographic data, to deduce information about the formation and variability of South Atlantic and Southern Ocean water masses. The Drake Passage surface waters south of the Polar Front (PF) are isotopically light (δ18O around −0.4‰) owing to the influence of meteoric waters. The salinity and δ18O of the A11 surface waters yield an apparent freshwater end-member which is much isotopically lighter than the local precipitation, thus advection of these waters from farther south dominates over local effects in determining the surface water properties. The Drake Passage section shows unusual proximity of the two main fronts of the Antarctic Circumpolar Current (the PF and Subantarctic Front (SAF)), and we observe cold, fresh, and isotopically light water derived from the temperature-minimum Winter Water at the SAF. This water is of the correct density to freshen the intermediate water north of the SAF and thus play a role in the formation of the comparatively fresh Antarctic Intermediate Water (AAIW) of the South Atlantic. This confirms the role of Antarctic water in forming the South Atlantic variety of AAIW. Across the A11 section the oxygen isotope and salinity data at the AAIW core show very similar traces, with waters in the Malvinas Current loop showing lowest values of both. At the eastern boundary of the South Atlantic, the input of Red Sea Water from east of South Africa is observed via the presence of anomalously isotopically heavy AAIW. We deduce potentially significant temporal variability in the isotopic composition of Weddell Sea Deep Water (WSDW) by comparing the Drake Passage data to earlier data covering the outflow of the Weddell Sea. The A11 data show WSDW consistent with such variability, indicating that its effects could persist in the waters as they flow north into the western South Atlantic. We speculate that such variability could be due to small changes in the amount of glacial ice melt in WSDW.

We present measurements of the stable isotopes of oxygen ( 18 O and 16 O) from seawater samples collected during the Antarctic Deep Outflow Experiment (ADOX) cruises in the Southern Ocean and southern Indian Ocean, February to March, 1993 and 1994. The data are used in conjunction with hydrographic data to infer characteristics of the formation and circulation of water masses found in the region. The waters on the continental shelf of Antarctica (adjacent to the Princess Elizabeth Trough; PET) are isotopically the lightest found due to the injection of about 1% of glacial meltwater, and are probably advected to the region from farther east by the current associated with the Antarctic Slope Front. They appear to be locally disassociated from the Antarctic Surface Water and Winter Water (WW) farther north in the PET. The WW of the Enderby Basin is isotopically lighter than the PET WW and also fresher, indicating the presence of an additional component of glacial meltwater or high-latitude precipitation. North of the Antarctic Circumpolar Current, the surface δ 18 O values correlate strongly with salinity, but extrapolate to an apparent freshwater endmember which is isotopically too light to be reasonable; advection and mixing of the water masses dominate over the local water balance at this location. The Subantarctic Mode Water of the southern Indian Ocean lies on the line of the surface waters in salinity-δ 18 O space due to its local formation by deep convection. The Antarctic Intermediate Water also lies on this line, but it is known that the major sources for this water mass are outside the region. Consequently this observation does not necessarily imply formation by local deep convection. The δ 18 O measurements have shown that the major sources for PET Antarctic Bottom Water (AABW) lie outside the Weddell and Ross seas. Based on the potential temperature-salinity of the PET AABW we further deduce that the PET itself is not the formation location of a significant amount of AABW. Its major component is advected to the region from the Australian-Antarctic Basin farther east.

Arhopalus ferus (Mulsant) (Coleoptera: Cerambycidae) is a forest pest that does not occur in Australia. In February 2010, the container ship Tatiana Schulte, en route from New Zealand, was refused permission to enter Australia following the discovery of numerous A. ferus aboard. The place where the infestation occurred was unknown, representing an uncontrolled biosecurity-risk pathway. Hydrogen isotope analysis of the beetles' wings showed that the infestation most likely originated from Auckland, New Zealand.

The aim of this study was to investigate the correlation of δ²H and δ¹³C of bulk milk powder and milk powder fatty acids to their production region. A total of 46 milk powder samples from across New Zealand were collected and analyzed. Principal component analysis (PCA) showed that the δ²H and δ¹³C of four fatty acids (C4:0, C14:0, C16:0, C18:1) and bulk milk powder were found to be correlated with regional production area. Linear discriminant analysis (LDA) models were prepared using different combinations of bulk and fatty acid δ²H and δ¹³C. All models were effective in discriminating samples from the North and South Islands. The LDA model using just fatty acid δ²H and δ¹³C provided the best separation. Therefore, the isotopic composition of the aforementioned fatty acids can be utilized as a good biomarker in milk powder that conveys reliable isotopic information to track milk powders to their regional origin.

The water column distributions of cadmium (Cd) and phosphorus (P) in the region of the subtropical convergence (STC) south of New Zealand have been studied. Mixed layer Cd concentrations were extremely low throughout the study area, varying from 0.012 to 0.059 nmol kg−1. In subantarctic waters south of the STC, deep-water Cd concentrations were intermediate between those of the North Atlantic and the North Pacific oceans, consistent with deep-water circulation. Cd varied linearly with P with a slope of 0.35 × 10−3 mol Cdmol P, but waters in the upper 1000 m were significantly depleted in Cd compared to temperate waters (zero-P intercept at − 0.23 nmol Cd kg−1). The lowest Cd concentrations were observed in subtropical waters north of the STC. Here the Cd-P slope was only 0.08 × 10−3 mol Cdmol P, indicating that the Cd-P properties in this region are dominated by mixing of low-Cd, high-P subantarctic water across the STC. Freshwater sources of Cd and P were found to be negligible. This work implies that the northern region of the Southern Ocean plays a major role in the global Cd-P relationship. Two mechanisms are suggested: (1) the ventilation of low-Cd-P subantarctic water to intermediate depth through Antarctic Intermediate Water formation, and (2) the remineralisation of low-Cd-P detritus from biota produced in waters formed at the STC.

Near-surface waters close to the Antarctic continent are found to have high cadmium concentrations with respect to phosphorus. These waters have been shown to be the major component in the local formation of Antarctic Bottom Water in this region. It is demonstrated that Antarctic Bottom Water so formed would have a high preformed cadmium to phosphorus ratio. The ventilation of the abyssal ocean with this water would contribute to the observed kink in the global cadmium to phosphorus relationship. This is an important conclusion for paleochemical studies and may account for part of the discrepancy between cadmium and carbon-13 paleochemical tracers observed in the Southern Ocean.

Data from a hydrographic survey located in the Princess Elizabeth Trough, near the Antarctic continent (63–65 ° S, 85 ° E) are presented and discussed. This region is covered by sea-ice for most of the year with the ice-edge retreating to the southern edge of the Trough during summer. Water samples were collected during the Austral summer, February 1993, to determine the ratio of the oxygen-18 to oxygen-16 isotope, δ18O. Four water bodies are characterised by their temperature, salinity and δ18O properties, Surface Water (0.0–1.2 ° C, 33.1–34.0, −0.39‰), Winter Water (−1.7 ° C, 34.4, −0.39‰), Warm Deep Water (2.0 ° C, 34.69, 0.02‰) and Bottom Water (−0.43 ° C, 34.669, −0.25‰). The Bottom Water is warmer, saltier and heavier isotopically than Weddell Sea Bottom Water (−0.9 ° C, 34.65, −0.29‰); and has T-S properties close to that of classical Antarctic Bottom Water (−0.4 ° C, 34.66). This Bottom Water is isotopically distinct from the Weddell Sea derived Bottom Water that ventilates the Indian ocean through the Kerguelen-Crozet gap. A mechanism for local formation of the Bottom Water involving freezing of Surface Water and entrainment of Warm Deep Water is described.

The carbon isotope method (AOAC 998.12) compares the bulk honey carbon isotope value with that of the extracted protein; a difference greater than 1‰ suggesting that the protein and the bulk carbohydrate have different origins. New Zealand Manuka honey is a high value product and often fails this test. It has been suggested such failures are due to the pollen in the Manuka honey and an adaptation of the method to remove pollen prior to testing has been proposed. Here we test 64 authentic honey samples collected directly from the hives and find that a large proportion (37%) of Manuka honeys fail the test. Of these 60% still fail the adapted method. These honey samples were collected and processed under stringent conditions and have not been adulterated post-harvest. More work is required to ascertain the cause of these test failures.

Diversity in guilds of primary producers enhances temporal stability in provision of organic matter to consumers. In the Antarctic ecosystem, where temporal variability in phytoplankton production is high, sea ice contains a diatom and microbial community (SIMCO) that represents a pool of organic matter that is seasonally more consistent, although of relatively small magnitude. The fate of organic material produced by SIMCO in Antarctica is largely unknown but may represent an important link between sea ice dynamics and secondary production in nearshore food webs. We used whole tissue and compound-specific stable isotope analysis of consumers to test whether the sea ice microbial community is an important source of organic matter supporting nearshore communities in the Ross Sea. We found distinct gradients in delta13C and delta15N of SIMCO corresponding to differences in inorganic carbon and nitrogen acquisition among sites with different sea ice extent and persistence. Mass balance analysis of a suite of consumers demonstrated large fluxes of SIMCO into the nearshore food web, ranging from 5% to 100% of organic matter supplied to benthic species, and 0-10% of organic matter to upper water column or pelagic inhabitants. A delta13C analysis of nine fatty acids including two key biomarkers for diatoms, eicosapentaenoic acid (EPA, 20:5omega3), and docosahexaenoic acid (DHA, 22:6omega3), confirmed these patterns. We observed clear patterns in delta13C of fatty acids that are enriched in 13C for species that acquire a large fraction of their nutrition from SIMCO. These data demonstrate the key role of SIMCO in ecosystem functioning in Antarctica and strong linkages between sea ice extent and nearshore secondary productivity. While SIMCO provides a stabilizing subsidy of organic matter, changes to sea ice coverage associated with climate change would directly affect secondary production and stability of benthic food webs in Antarctica.

第2回極域科学シンポジウム 共通セッション「大気-海洋-雪氷-固体地球の相互作用」 11月15日（火） 統計数理研究所 3階リフレッシュフロア