AN EVALUATION OF SAS/GRAPH SOFTWARE FOR COMPUTER CARTOGRAPHY1

The SAS® computer software system, widely used and respected for its capabilities in statistical analysis and data base management, now includes a new set of graphic and cartographic procedures called SAS GRAPH?. We have used these cartographic procedures in research on mapping ethno-cultural census data from metropolitan areas in Ontario and in undergraduate and graduate courses in computer cartography. On the basis of that experience, we describe and evaluate SAS/GRAPH'S cartographic capabilities and illustrate with maps drawn by various devices.     

Combining pixel and object based image analysis of ultra-high resolution multibeam bathymetry and backscatter for habitat mapping in shallow marine waters

Habitat mapping data are increasingly being recognised for their importance in underpinning marine spatial planning. The ability to collect ultra-high resolution (cm) multibeam echosounder (MBES) data in shallow waters has facilitated understanding of the fine-scale distribution of benthic habitats in these areas that are often prone to human disturbance. Developing quantitative and objective approaches to integrate MBES data with ground observations for predictive modelling is essential for ensuring repeatability and providing confidence measures for habitat mapping products. Whilst supervised classification approaches are becoming more common, users are often faced with a decision whether to implement a pixel based (PB) or an object based (OB) image analysis approach, with often limited understanding of the potential influence of that decision on final map products and relative importance of data inputs to patterns observed. In this study, we apply an ensemble learning approach capable of integrating PB and OB Image Analysis from ultra-high resolution MBES bathymetry and backscatter data for mapping benthic habitats in Refuge Cove, a temperate coastal embayment in south-east Australia. We demonstrate the relative importance of PB and OB seafloor derivatives for the five broad benthic habitats that dominate the site. We found that OB and PB approaches performed well with differences in classification accuracy but not discernible statistically. However, a model incorporating elements of both approaches proved to be significantly more accurate than OB or PB methods alone and demonstrate the benefits of using MBES bathymetry and backscatter combined for class discrimination.     

Analysis of dislocations in some naturally deformed plagioclase feldspars

Dislocations in intermediate plagioclase feldspars, which were deformed under granulite facies conditions, have been analysed. The study reveals extensive ductile deformation by intracrystalline slip and by twinning. Six out of the seven possible Burgers vectors were identified: \(b = \left[ {001} \right],\tfrac{1}{2}\left[ {110} \right],\tfrac{1}{2}\left[ {1\bar 10} \right],\left[ {101} \right],\tfrac{1}{2}\left[ {112} \right]and\tfrac{1}{2}\left[ {1\bar 12} \right]\) . Most, perhaps all, dislocations are dissociated by up to 200 Å. The microstructure is dominated by [001] screw dislocations, most of which appear to be dissociated in (010). The dominant slip system appears to be (010) [001]. Large grain-to-grain variations in the density of free dislocations indicate that the plastic strain in individual grains depended upon the Schmid factor for (010) [001]. The microstructure suggests that the rate-controlling step for high-temperature creep of plagioclase is cross-slip of extended [001] screw dislocations. The rheological contrast between feldspar and quartz is partly due to a difference in stacking fault energy.     

Sources and distribution of organic matter in a river-dominated estuary (Winyah Bay, SC, USA)

The sources and distribution of organic matter (OM) in surface waters and sediments from Winyah Bay (South Carolina, USA) were investigated using a variety of analytical techniques, including elemental, stable isotope and organic biomarker analyses. Several locations along the estuary salinity gradient were sampled during four different periods of contrasting river discharge and tidal range. The dissolved organic carbon (DOC) concentrations of surface waters ranged from 7 mg l⁻¹ in the lower bay stations closest to the ocean to 20 mg l⁻¹ in the river and upper bay samples. There was a general linear relationship between DOC concentrations and salinity in three of the four sampling periods. In contrast, particulate organic carbon (POC) concentrations were significantly lower (0.1–3 mg l⁻¹) and showed no relationship with salinity. The high molecular weight dissolved OM (HMW DOM) isolated from selected water samples collected along the bay displayed atomic carbon:nitrogen ratios ([C/N]a) and stable carbon isotopic compositions of organic carbon (δ¹³C_OC) that ranged from 10 to 30 and from −28 to −25‰, respectively. Combined, such compositions indicate that in most HMW DOM samples, the majority of the OM originates from terrigenous sources, with smaller contributions from riverine and estuarine phytoplankton. In contrast, the [C/N]a ratios of particulate OM (POM) samples varied significantly among the collection periods, ranging from low values of 5 to high values of >20. Overall, the trends in [C/N]a ratios indicated that algal sources of POM were most important during the early and late summer, whereas terrigenous sources dominated in the winter and early spring.In Winyah Bay bottom sediments, the concentrations of the mineral-associated OM were positively correlated with sediment surface area. The [C/N]a ratios and δ¹³C_OC compositions of the bulk sedimentary OM ranged from 5 to 45 and from −28 to −23‰, respectively. These compositions were consistent with predominant contributions of terrigenous sources and lesser (but significant) inputs of freshwater, estuarine and marine phytoplankton. The highest terrigenous contents were found in sediments from the river and upper bay sites, with smaller contributions to the lower parts of the estuary. The yields of lignin-derived CuO oxidation products from Winyah Bay sediments indicated that the terrigenous OM in these samples was composed of variable mixtures of relatively fresh vascular plant detritus and moderately altered soil OM. Based on the lignin phenol compositions, most of this material appeared to be derived from angiosperm and gymnosperm vascular plant sources similar to those found in the upland coastal forests in this region. A few samples displayed lignin compositions that suggested a more significant contribution from marsh C₃ grasses. However, there was no evidence of inputs of Spartina alterniflora (a C₄ grass) remains from the salt marshes that surround the lower sections of Winyah Bay.     

Estimation of meiobenthic nematode diversity by non-specialists

A methodology is presented for the estimation of nematode diversity using Cairns' technique of sequential comparisons. The accuracy and precision of the method are examined and a test presented for the comparison of diversity estimates.     

Cadmium and phosphorus cycling in the water column of the South China Sea: The roles of biotic and abiotic particles

The concentrations of cadmium, phosphorus, and aluminum in size-fractionated phytoplankton, zooplankton, and sinking particles are determined using ICPMS to evaluate the roles of biotic and abiotic particles on the cycling and ratios of Cd and P in the water column. Plankton were collected with a filtration apparatus equipped with 10-, 60-, and 150-μm aperture plankton nets on two occasions (2002 and 2006), and sinking particles were sampled by moored sediment traps deployed at depths of 120, 600, and 3500 m from 2004 to 2005. In contrast to what our previous study revealed, i.e., that most of the other bioactive trace metals in plankton were strongly correlated with abiotic Al and adsorbed on phytoplankton [Ho, T.Y., Wen, L.S., You, C.F., Lee, D.C., 2007. The trace metal composition of size-fractionated plankton in the South China Sea: biotic versus abiotic sources. Limnol Oceanogr 52, 1776–88.], Cd/P ratios, ranging from 0.12 to 0.34 mmol/mol P, did not vary with Al and exhibited fairly consistent values among different sizes of plankton, showing that Cd was mostly incorporated on an intracellular basis. In terms of the sinking particles, fluxes in Cd and P as well as in Cd/P ratios were strongly influenced by both biotic and abiotic particles. Overall, the Cd/P ratios in the sinking particles ranged from 0.03 to 1.2 mmol/mol, with the highest value observed in traps at 120 m during the productive season. The lowest value was observed in deep water during high flux periods for lithogenic particles. At surface depth, flux and Cd/P ratios were elevated during the most productive season in the region. The elevated ratios in the traps at 120 m were most likely related to preferential uptake of Cd for the dominant species (coccolithophores) during the productive period. Relatively, Cd/P ratios sharply decreased with increasing Al flux in deep water and ratios were much lower than the expected Cd/P ratios obtained from the relative portion of lithogenic and biogenic particles, indicating that the adsorption of soluble P into lithogenic particles was significant in the deep water during high lithogenic particle flux periods. Using averaged annual fluxes and standing stock in the water column, the residence time of biogenic Cd and P are 0.10 and 0.20, 250 and 100, and 9100 and 5000 years respectively in the top 120 m, 600 m, and water column as a whole, also showing preferential removal for Cd in the euphotic zone but relatively higher removal rates for P in the deep water. Our study suggests that the shift in microalgal community structure along with input of lithogenic minerals are both potentially important factors in influencing Cd/P ratios in oceanic water on a geological time scale.     

Whitefish wars: Pangasius, politics and consumer confusion in Europe

Rapid growth in production of the farmed Vietnamese whitefish pangasius and its trade with the European Union has provoked criticism of the fish's environmental, social and safety credentials by actors including WWF and Members of the European Parliament and associated negative media coverage. This paper reviews the range of claims communicated about pangasius (identified as a form of mass mediated risk governance), in light of scientific evidence and analysis of data from the EU's Rapid Alert System for Food and Feeds food safety notification system for imported seafood. This analysis shows pangasius to be generally safe, environmentally benign and beneficial for actors along the international value chains that characterise the trade. The case is made that increasingly politicised debates in Europe around risk and uncertainty are potentially counterproductive for EU seafood security and European aquaculture industry, and that the trade in pangasius can contribute to sustainable seafood consumption in a number of ways. Transparent evidence-based assessment and systems for communicating complex issues of risk for products such as pangasius are required in order to support continuance of fair and mutually beneficial trade.     

Iron(III) accumulations in inland saline waterways,Hunter Valley,Australia: Mineralogy,micromorphology and pore-water geochemistry

Discharge of Fe(II)-rich groundwaters into surface-waters results in the accumulation of Fe(III)-minerals in salinized sand-bed waterways of the Hunter Valley, Australia. The objective of this study was to characterise the mineralogy, micromorphology and pore-water geochemistry of these Fe(III) accumulations. Pore-waters had a circumneutral pH (6.2–7.2), were sub-oxic to oxic (Eh 59–453 mV), and had dissolved Fe(II) concentrations up to 81.6 mg L⁻¹. X-ray diffraction (XRD) on natural and acid-ammonium-oxalate (AAO) extracted samples indicated a dominance of 2-line ferrihydrite in most samples, with lesser amounts of goethite, lepidocrocite, quartz, and alumino-silicate clays. The majority of Fe in the samples was bound in the AAO extractable fraction (Fe^Ox) relative to the Na-dithionite extractable fraction (Fe^Di), with generally high Fe^Ox:Fe^Di ratios (0.52–0.92). The presence of nano-crystalline 2-line ferrihydrite (Fe₅HO₃·4H₂O) with lesser amounts of goethite (α-FeOOH) was confirmed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM) coupled with selected area electron diffraction (SAED). In addition, it was found that lepidocrocite (γ-FeOOH), which occurred as nanoparticles as little as ∼5 lattice spacings thick perpendicular to the (0 2 0) lattice plane, was also present in the studied Fe(III) deposits. Overall, the results highlight the complex variability in the crystallinity and particle-size of Fe(III)-minerals which form via oxidation of Fe(II)-rich groundwaters in sand-bed streams. This variability may be attributed to: (1) divergent precipitation conditions influencing the Fe(II) oxidation rate and the associated supply and hydrolysis of the Fe(III) ion, (2) the effect of interfering compounds, and (3) the influence of bacteria, especially Leptothrix ochracea.     

Minimum Bedrock Exposure Ages and Their Implications: Larsemann Hills and Neighboring Bolingen Islands, East Antarctica

<正>Considerable controversy exists over whether or not extensive glaciation occurred during the global Last Glacial Maximum(LGM) in the Larsemann Hills.In this study we use the in situ produced cosmogenic nuclide ~(10)Be(half life 1.51 Ma) to provide minimum exposure ages for six bedrock samples and one erratic boulder in order to determine the last period of deglaciation in the Larsemann Hills and on the neighboring Bolingen Islands.Three bedrock samples taken from Friendship Mountain(the highest peak on the Mirror Peninsula,Larsemann Hills;～2 km from the ice sheet) have minimum exposure ages ranging from 40.0 to 44.7 ka.The erratic boulder from Peak 106(just at the edge of the ice sheet) has a younger minimum exposure age of only 8.8 ka.The minimum exposure ages for two bedrock samples from Blundell Peak(the highest peak on Stornes Peninsula,Larsemann Hills;～2 km from the ice sheet) are about 17 and 18 ka.On the Bolingen Islands(southwest to the Larsemann Hills;～10 km from the ice sheet),the minimum exposure age for one bedrock sample is similar to that at Friendship Mountain(i.e.,44 ka).Our results indicate that the bedrock exposure in the Larsemann Hills and on the neighboring Bolingen Islands commenced obviously before the global LGM(i.e.,20-22 ka),and the bedrock erosion rates at the Antarctic coast areas may be obviously higher than in the interior land.