Benthic foraminiferal abundances in Late Cretaceous sediments of the Tethys

Benthic foraminiferal distribution patterns throughout the late Maastrichtian Tethyan deep sea are analyzed. Many species are ubiquitously distributed throughout this region and therefore it is hard to assess their ecological preferences. However, five species show distribution patterns, which suggest that they may have distinctive paleoenvironmental preferences. These preferences are interpreted from hypothesized surface circulation and upwelling patterns. Additional information comes from Recent benthic foraminiferal ecology and from responses to the Cretaceous/Paleogene (k/Pg) boundary event. This enables us to assess the ecological preferences of these late Maastrichtian taxa, and establish them as ecological-marker (ecomarker) species for paleoenvironmental interpretation of the late Maastrichtian bathyal-abyssal Tethyan realm. (1) Eouvigerina subsculpturu is suggested to be indicative of reasonably oxygenated upper-middle bathyal environments, though with high abundance of utilizable organic matter. (2) Sliteria varsoviensis is linked to areas of late Maastrichtian upwelling and seems to have been an epibenthic species with an opportunistic life mode. (3) Guvelinellu beccuriiformis and (4) Nuttullides truempyi are considered to be indicative of oligotrophic conditions unless they occur with a large proportion of endobenthic morphotypes. (5) Guvelinellu pertusu is proposed to indicate neritic-middle bathyal environments of the 'boreal' realm, which might be influenced by more seasonal food-fluxes and by higher oxygen levels than similar settings in the (sub)tropics. Finally, the anomalous high abundances of the buliminid species Sitella cf. plunu in deep open ocean environments is discussed in terms of possible mechanisms permitting such a (morphologically) opportunistic species to thrive in such an assumedly oligotrophic environment.

(Table 2, page 1376) Chemical analyses of manganese nodules and crusts from the South-western Pacific

Phosphate deposits which apparently formed during the Miocene climatic optimum are widespread on the Chatham Rise and Camp bell Plateau, and on seamounts in the north Tasman Sea. They formed under oxidising conditions by the phosphatisation of older or contemporaneous foraminiferal oozes (Campbell Plateau and Chatham Rise) and coral limestones (Tasman Sea). The phosphorites of the rise and plateau were formed where current activity was sufficiently strong to prevent normal sedimentation, and now form lag deposits. After the Miocene, phosphorite formation ceased and was followed by manganese oxide deposition where conditions were highly oxidising on the eastern Campbell Plateau and north Tasman seamounts, and by glauconite formation in the much less oxidising environments of the western Campbell Plateau and the Chat ham Rise. The manganese deposits are not volcanogenic, as was formerly thought, but formed by slow precipitation from well oxygenated sea water.

Mineralogical, geochemical and magnetic signatures of surface sediments from the Canadian Beaufort Shelf and Amundsen Gulf (Canadian Arctic)

Mineralogical, geochemical, magnetic, and siliciclastic grain-size signatures of 34 surface sediment samples from the Mackenzie-Beaufort Sea Slope and Amundsen Gulf were studied in order to better constrain the redox status, detrital particle provenance, and sediment dynamics in the western Canadian Arctic. Redox-sensitive elements (Mn, Fe, V, Cr, Zn) indicate that modern sedimentary deposition within the Mackenzie-Beaufort Sea Slope and Amundsen Gulf took place under oxic bottom-water conditions, with more turbulent mixing conditions and thus a well-oxygenated water column prevailing within the Amundsen Gulf. The analytical data obtained, combined with multivariate statistical (notably, principal component and fuzzy c-means clustering analyses) and spatial analyses, allowed the division of the study area into four provinces with distinct sedimentary compositions: (1) the Mackenzie Trough-Canadian Beaufort Shelf with high phyllosilicate-Fe oxide-magnetite and Al-K-Ti-Fe-Cr-V-Zn-P contents; (2) Southwestern Banks Island, characterized by high dolomite-K-feldspar and Ca-Mg-LOI contents; (3) the Central Amundsen Gulf, a transitional zone typified by intermediate phyllosilicate-magnetite-K-feldspar-dolomite and Al-K-Ti-Fe-Mn-V-Zn-Sr-Ca-Mg-LOI contents; and (4) mud volcanoes on the Canadian Beaufort Shelf distinguished by poorly sorted coarse-silt with high quartz-plagioclase-authigenic carbonate and Si-Zr contents, as well as high magnetic susceptibility. Our results also confirm that the present-day sedimentary dynamics on the Canadian Beaufort Shelf is mainly controlled by sediment supply from the Mackenzie River. Overall, these insights provide a basis for future studies using mineralogical, geochemical, and magnetic signatures of Canadian Arctic sediments in order to reconstruct past variations in sediment inputs and transport pathways related to late Quaternary climate and oceanographic changes.

Ostracoda in surface sediments of the Arctic Ocean

Ostracodes were studied from deep Arctic Ocean cores obtained during the Arctic 91 expedition of the Polarstern to the Nansen, Amundsen and Makarov Basins, the Lomonosov Ridge, Morris Jesup Rise and Yermak Plateau, in order to investigate their distribution in Arctic Ocean deep water (AODW) and apply these data to paleoceanographic reconstruction of bottom water masses during the Quaternary. Analyses of coretop assemblages from Arctic 91 boxcores indicate the following: ostracodes are common at all depths between 1000 and 4500 m, and species distribution is strongly influenced by water mass characteristics and bathymetry; quantitative analyses comparing Eurasian and Canada Basin assemblages indicate that distinct assemblages inhabit regions east and west of the Lomonosov Ridge, a barrier especially important to species living in lower AODW; deep Eurasian Basin assemblages are more similar to those living in Greenland Sea deep water (GSDW) than those in Canada Basin deep water; two upper AODW assemblages were recognized throughout the Arctic Ocean, one living between 1000 and 1500 m, and the other, having high species diversity, at 1500-3000 m. Downcore quantitative analyses of species' abundances and the squared chord distance coefficient of similarity reveals a distinct series of abundance peaks in key indicator taxa interpreted to signify the following late Quaternary deep water history of the Eurasian Basin. During the Last Glacial Maximum (LGM), a GSDW/AODW assemblage, characteristic of cold, well oxygenated deep water > 3000 m today, inhabited the Lomonosov Ridge to depths as shallow as 1000 m, perhaps indicating the influence of GSDW at mid-depths in the central Arctic Ocean. During Termination 1, a period of high organic productivity associated with a strong inflowing warm North Atlantic layer occurred. During the mid-Holocene, several key faunal events indicate a period of warming and/or enhanced flow between the Canada and Eurasian Basins. A long-term record of ostracode assemblages from kastenlot core PS2200-5 (1073 m water depth) from the Morris Jesup Rise indicates a quasi-cyclic pattern of water mass changes during the last 300 kyr. Interglacial ostracode assemblages corresponding to oxygen isotope stages 1, 5, and 7 indicate rapid changes in dissolved oxygen and productivity during glacial-interglacial transitions.

(Table 2) Location, age of accompanied sediments, chemical and Sr isotopic compositions of manganese nodules in DSDP/ODP cores

Strontium isotopic compositions of acetic acid (HOAc) leachate fractions of eight manganese oxide deposits from the modern seafloor, and of twenty-one buried manganese nodules from Cretaceous to Recent sediments in DSDP/ODP cores were measured. ratios of HOAc leachates in all modern seafloor manganese oxides of various origins are identical with present seawater. The ratios of the HOAc leachates of buried nodules from DSDP/ODP cores are significantly lower than those of nodules from the modern seafloor and are mostly identical with coeval seawater values estimated from the age of associated sediments. It is suggested that the buried nodules in DSDP/ODP cores are not artifacts transported from the present seafloor during the drilling process, but are in situ fossil deposits from the past deep-sea floor during Cretaceous to Quaternary periods. The formation of deep-sea fossil nodules prior to the formation of Antarctic Bottom Water (AABW) indicates that the circulation of oxygenated deep seawaters have activately deposited manganese oxides since the Eocene Epoch, or earlier.

Seasonal variability in microbial methanol utilisation in coastal waters of the western English Channel

Methanol is ubiquitous in seawater and the most abundant oxygenated volatile organic compound (OVOC) in the atmosphere where it influences oxidising capacity and ozone formation. Marine methylotrophic bacteria utilise methanol in seawater both as an energy and/or growth substrate. This work represents the first fully resolved seasonal study of marine microbial methanol uptake dynamics. Rates of microbial methanol dissimilation in coastal surface waters of the UK varied between 0.7 – 11.2 nmol l-1 h-1 and reached a maximum in February. Rates of microbial methanol assimilation varied between 0.04 – 2.64 x 10-2 nmol l-1 h-1 and reached a maximum in August. Temporal variability in microbial methanol uptake rates shows that methanol assimilation and dissimilation display opposing seasonal cycles, although overall <1% of methanol was assimilated. Correlative approaches with 16S rRNA pyrosequencing data suggested that bacteria of the SAR11 clade and Rhodobacterales could be significantly influencing rates of methanol dissimilation and assimilation, respectively, at station L4 in the western English Channel

Seasonal variability in microbial methanol utilisation in coastal waters of the western English Channel

Methanol is ubiquitous in seawater and the most abundant oxygenated volatile organic compound (OVOC) in the atmosphere where it influences oxidising capacity and ozone formation. Marine methylotrophic bacteria utilise methanol in seawater both as an energy and/or growth substrate. This work represents the first fully resolved seasonal study of marine microbial methanol uptake dynamics. Rates of microbial methanol dissimilation in coastal surface waters of the UK varied between 0.7 – 11.2 nmol l-1 h-1 and reached a maximum in February. Rates of microbial methanol assimilation varied between 0.04 – 2.64 x 10-2 nmol l-1 h-1 and reached a maximum in August. Temporal variability in microbial methanol uptake rates shows that methanol assimilation and dissimilation display opposing seasonal cycles, although overall <1% of methanol was assimilated. Correlative approaches with 16S rRNA pyrosequencing data suggested that bacteria of the SAR11 clade and Rhodobacterales could be significantly influencing rates of methanol dissimilation and assimilation, respectively, at station L4 in the western English Channel

Essential scientific mapping of the value chain of thermochemical converted second-generation bio-fuels

As the largest contributor to renewable energy, biomass (especially lignocellulosic biomass) has significant potential to address atmospheric emission and energy shortage issues. The bio-fuels derived from lignocellulosic biomass are popularly referred to as second-generation bio-fuels. To date, several thermochemical conversion pathways for the production of second-generation bio-fuels have shown commercial promise; however, most of these remain at various pre-commercial stages. In view of their imminent commercialization, it is important to conduct a profound and comprehensive comparison of these production techniques. Accordingly, the scope of this review is to fill this essential knowledge gap by mapping the entire value chain of second-generation bio-fuels, from technical, economic, and environmental perspectives. This value chain covers i) the thermochemical technologies used to convert solid biomass feedstock into easier-to-handle intermediates, such as bio-oil, syngas, methanol, and Fischer-Tropsch fuel; and ii) the upgrading technologies used to convert intermediates into end products, including diesel, gasoline, renewable jet fuels, hydrogen, char, olefins, and oxygenated compounds. This review also provides an economic and commercial assessment of these technologies, with the aim of identifying the most adaptable technology for the production of bio-fuels, fuel additives, and bio-chemicals. A detailed mapping of the carbon footprints of the various thermochemical routes to second-generation bio-fuels is also carried out. The review concludes by identifying key challenges and future trends for second-generation petroleum substitute bio-fuels.

Geochemical analysis at ODP Site 207-1261 from the Demerara Rise in the western equatorial Atlantic

A high-resolution geochemical record of a 120 cm black shale interval deposited during the Coniacian-Santonian Oceanic Anoxic Event 3 (ODP Leg 207, Site 1261, Demerara Rise) has been constructed to provide detailed insight into rapid changes in deep ocean and sediment paleo-redox conditions. High contents of organic matter, sulfur and redox-sensitive trace metals (Cd, Mo, V, Zn), as well as continuous lamination, point to deposition under consistently oxygen-free and largely sulfidic bottom water conditions. However, rapid and cyclic changes in deep ocean redox are documented by short-term (~15-20 ka) intervals with decreased total organic carbon (TOC), S and redox-sensitive trace metal contents, and in particular pronounced phosphorus peaks (up to 2.5 wt% P) associated with elevated Fe oxide contents. Sequential iron and phosphate extractions confirm that P is dominantly bound to iron oxides and incorporated into authigenic apatite. Preservation of this Fe-P coupling in an otherwise sulfidic depositional environment (as indicated by Fe speciation and high amounts of sulfurized organic matter) may be unexpected, and provides evidence for temporarily non-sulfidic bottom waters. However, there is no evidence for deposition under oxic conditions. Instead, sulfidic conditions were punctuated by periods of anoxic, non-sulfidic bottom waters. During these periods, phosphate was effectively scavenged during precipitation of iron (oxyhydr)oxides in the upper water column, and was subsequently deposited and largely preserved at the sea floor. After ~15-25 ka, sulfidic bottom water conditions were re-established, leading to the initial precipitation of CdS, ZnS and pyrite. Subsequently, increasing concentrations of H2S in the water column led to extensive formation of sulfurized organic matter, which effectively scavenged particle-reactive Mo complexes (thiomolybdates). At Site 1261, sulfidic bottom waters lasted for ?90-100 ka, followed by another period of anoxic, non-sulfidic conditions lasting for ~15-20 ka. The observed cyclicity at the lower end of the redox scale may have been triggered by repeated incursions of more oxygenated surface- to mid-waters from the South Atlantic resulting in a lowering of the oxic-anoxic chemocline in the water column. Alternatively, sea water sulfate might have been stripped by long-lasting high rates of sulfate reduction, removing the ultimate source for HS**- production.

Structural aspects of reversible molecular oxygen uptake

The system IrX(CO)[P(C6H5)3]3 in benzene solution adds molecular oxygen reversibly if X is chlorine and irreversibly if X is iodine. The crystal structure of the complex IrIO 2(CO)[P(C6H5)3]2 · CH2Cl2 is reported here and compared with a previous study of the structure of IrClO2(CO)[P(C6H 5)3]2. The O-O bond length is 1.47 ± 0.02 angstroms in the irreversibly oxygenated iodo-compound and 1.30 ± 0.03 angstroms in the reversibly oxygenated chlorocompound.

Seep communities from two mud volcanoes in the deep eastern Mediterranean Sea: faunal composition, spatial patterns and environmental control

The Mediterranean Sea constitutes a unique environment to study cold-seep ecosystems due to the presence of different geodynamic settings, from an active margin along the Mediterranean Ridge (MR) to a passive margin in the Nile Deep-Sea Fan (NDSF). We attempted to identify the structure of benthic communities associated with the Napoli and Amsterdam mud volcanoes (MVs) located on the MR and to establish the links between faunal distribution and environmental conditions at different spatial scales. Comparison between the 2 MVs revealed that the faunal distribution seemed to be mainly controlled by the characteristics of the microhabitats. On both geological structures, the variability between the different microhabitats was higher than the variability observed between replicates of the same microhabitat, and the distribution of macro-fauna was apparently linked to gradients in physico-chemical conditions. The peripheral sites from Napoli were generally more oxygenated and harboured lower species richness than the active sites. The reduced sediment microhabitat from Amsterdam presented the highest methane concentrations and was mainly colonised by symbiont-bearing vesicomyid bivalves and heterotrophic dorvilleid polychaetes. Overall, a higher taxonomic diversity was observed on Napoli. Sub-stratum type was hypothesised to be the second factor influencing faunal distribution. The results of this study highlight the high heterogeneity of faunal communities associated with seep ecosystems within this region and the need to pursue investigations at various spatial and temporal scales.

Towards balanced exploitation and management of the fishery resources of Uganda

A casual study of the hydrological map of Uganda would convince every serious fisherman and fisheater that he is most favoured to be in Uganda. The extent and distribution of the country's aquatic system plus the rich variety of fish species there is promises a fishery potential of considerable magnitude: The open waterways comprised by the Uganda portions of Lakes Victoria, Albert and Edward; and Lakes Kyoga, George plus minor lakes Wamala, Kijanebarora, mutanda, etc. occupy about 15% of the total surface area (91,000 m2; Depart. Land Survey, 1962). Most of the nation's fish supplies are currontly from this source. 1.2. A rich network of permanent and seasonal rivers and streams filling and/or emptying various water systems covers most of Uganda. This aquatic network is associated with a fish fauna whose immense significance as a source of protein is perhaps better appreciated by the local subsistance fisherman and consumer than by the fisheries scientist and manager in this country. Many species of this fish fauna have strong affinities with the open water systems while some are typically riverine. 1.3. Then there are wetlands composed mainly of expanses of swamp, but including some areas of bog. These cover about 2% of the country. While the variety of fish fauna found here is limited by the rather hostile nature of the environment (comparatively de-oxygenated under a canopy of dense stands of emergont vegetation) several specialised fishes e.g. Clarias spp. and Protpterus aethiopicus (Kamongo) occur here. Availability of permanent and seasonal sources of water, well distributed throughout most areas of Uganda, opens up immense potential for a variety of aquaculture practices. However, while active exploitation of much of these fishery resources is currently underway, important questions regarding the magnitudes of the various resource potentials and dynamics, and about suitable levels and modes of exploitation, are yet unanswered. These gaps in knowledge go about the fishery resources of Uganda would hinder formulation of adequate development and management schemes. This short paper examines some of the above problems and suggests some approaches towards balanced oxploitation and management of the fisheries of Uganda.

Formation of seep carbonates along the makran convergent margin, northern Arabian sea and a molecular and isotopic approach to constrain the carbon isotopic composition of parent methane

Authigenic carbonate deposits have been sampled with the remotely operated vehicle ‘MARUM-QUEST 4000 m’ from five methane seeps between 731 and 1823 m water depth along the convergent Makran continental margin, offshore Pakistan (northern Arabian Sea). Two seeps on the upper slope are located within the oxygen minimum zone (OMZ; ca. 100 to 1100 m water depth), the other sites are situated in oxygenated water below the OMZ (below 1100 m water depth). The carbonate deposits vary with regard to their spatial extent, sedimentary fabrics, and associated seep fauna: Within the OMZ, carbonates are spatially restricted and associated with microbial mats, whereas in the oxygenated zone below the OMZ extensive carbonate crusts are exposed on the seafloor with abundant metazoans (bathymodiolin mussels, tube worms, galatheid crabs). Aragonite and Mg-calcite are the dominant carbonate minerals, forming common early diagenetic microcrystalline cement and clotted to radial-fibrous cement. The δ18Ocarbonate values range from 1.3 to 4.2‰ V-PDB, indicating carbonate precipitation at ambient bottom-water temperature in shallow sediment depth. Extremely low δ13Ccarbonate values (as low − 54.6‰ V-PDB) point to anaerobic oxidation of methane (AOM) as trigger for carbonate precipitation, with biogenic methane as dominant carbon source. Prevalence of biogenic methane in the seepage gas is corroborated by δ13Cmethane values ranging from − 70.3 to − 66.7‰ V-PDB, and also by back-calculations considering δ13Cmethane values of carbonate and incorporated lipid biomarkers. These calculations (Δδ13Cmethane–carbonate, Δδ13CANME–methane, Δδ13CMOX–methane) prove to be useful to assess the carbon stable isotope composition of seeping methane if this has not been determined in the first place; such an approach represents a useful tool to reconstruct fluid composition of ancient seeps. AOM is also revealed by lipid biomarkers of anaerobic methane oxidizing archaea such as crocetane, pentamethylicosane (PMI), and sn2-hydroxyarchaeol strongly depleted in 13C (δ13C values as low as − 127‰ V-PDB). Biomarkers of sulphate-reducing bacteria are also abundant, showing slightly less negative δ13C values, but still significantly 13C-depleted (average values as low as − 101‰). Other bacterial biomarkers, such as bacteriohopanepolyols (BHPs), hopanols, and hopanoic acids are detected in most carbonates, but are particularly common in seep carbonates from the non-OMZ sites. The BHP patterns of these carbonates and their low δ13C values resemble patterns of aerobic methanotrophic bacteria. In the shallower OMZ sites, BHPs revealed much lower contents and varying compositions, most likely reflecting other sources than aerobic methanotrophic bacteria. 230Th/U carbonate ages indicate that AOM-induced carbonate precipitation at the deeper non-OMZ seeps occurred mainly during the late Pleistocene-Holocene transition, i.e. between 19 and 15 ka before present, when the global sea level was lower than today.

Caracterização química, atividade antioxidante e antimicrobiana do óleo essencial de Baccharis oreophila Malme

The Baccharis oreophila Malme belongs to the Asteraceae family. In Brazil are reported 120 species of Baccharis, most located in the South and Southeast regions, the latter presents the highest prevalence, especially in the state of São Paulo. Asteraceae is well known for the production of essential oils, which are liquid, volatile and aromatic substances produced by plants specialized for metabolism possess antibacterial, antifungal, and antioxidant properties. Thus, this study aimed, perform chemical and evaluate the antimicrobial and antioxidant activity of essential oil from dried leaves of B. oreophila collected in winter in Piraquara, Paraná. Obtaining essential oil was given by hydrodistillation in Clevenger apparatus, in triplicate, and the analysis was done using a gas chromatograph coupled to mass spectrometry GC / MS. The identification of the components was made based on retention indices calculated from the co-injection of a series of n-alkanes, followed by comparison of their mass spectra with literature. The antimicrobial activity was assessed by disk diffusion method and microdilution. The antioxidant activity was evaluated by the methods DPPH equivalent Trolox, ABTS and FRAP equivalent Trolox equivalent ferrous sulfate. The essential oil showed 0.47% yield. They identified 57 components (89.38%), 1.51% were classified as hydrogenated monoterpenes, oxygenated monoterpenes 15.14%, 34.84% and 37.87% hydrogenated sesquiterpenes sesquiterpenes oxygenates. As the major components were detected kusimono (16.37%), spathulenol (16.12%), the δ-cadinene (5.68%) and bicyclogermacrene (4.09%). The antimicrobial activity of essential oil was performed for the microorganisms Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Candida albicans ATCC 18804 and Candida tropicalis ATCC 13803, the results showed that the essential oil showed activity against S. aureus Inhibitory Concentration minimum (CIM) 1250 g/mL. In the evaluation of antioxidant activity essential oil showed antioxidant potential for the three methods evaluated, with values of 1,468 m.mol.L-1, 7.126 m.mol.L-1 and 45.515 m.mol.L-1 for ABTS, DPPH and FRAP, respectively. These results demonstrate that the essential oil of B. oreophila showed antimicrobial potential against S. aureus and interesting antioxidant activity, especially for the reducing power of iron ion, demonstrating their potential for future industrial applications. It is important to emphasize that were not observed in the literature reports highlighting such biological properties of B. oreophila oil.

Aspects of the biology of Lutraria lutraria (L.) (bivalvia : Mactracea)

The life history of a population of Lutraria lutraria in a depth of 7m at Hunterston, Ayrshire is discussed. Much of the present population Is thought to have settled in 1967. The functional morphology of Lutraria is described and related to its life as a large, deep-burrowing bivalve. Lutraria spawned in late spring and continued to do so through the summer in 1979 and 1980. Animals became spent in August and September. Unsuccessful attempts were made to induce spawning in the laboratory. Artificial fertilization was successful but development did not proceed beyond the ciliated gastrula stage. Larvae of Lutraria were not identified in plankton samples and young stages were not encountered in sieved sediment samples. The biochemical cycle of the total animal and five component parts (gonad and visceral mass, digestive gland, adductor muscle, siphon and 'other' tissue) is investigated. A marked increase in weight, reflected in an increase in weight of the component parts, was recorded in Autumn 1979. This is thought to be related to an exceptional increase in the phytoplankton at this time. Although a relationship between the biochemical cycle and reproductive cycle remains uncertain, definite seasonal changes were recorded in the respiration rate of Lutraria. At 10°C, the maximum rate of a standard 20g animal was 0.1283m1s 02/g. dry wt./hr. in May 1980 and the minimum rate was 0.O59mls 02/g. dry wt./hr. in October 1980. The effect of temperature on respiration rate was also investigated. Significant differences were recorded for five experimental temperatures (10°C, 15°C, 20°C, 25°C and 30 °C) in August and October but only between two temperatures (10 C and 30 C) in April. There was a decrease in respiration rate at 30 C in August and October, but an increase in April. Respiration rate is affected by a reduction in oxygen tension. A variety of responses were recorded with a small degree of regulation shown. Individuals of Lutraria were able to survive 48 hours under anaerobic conditions. In fully oxygenated conditions heart rate ranged from 4-15 beats per minute with an average of 8 beats per minute. Heart beat was markedly affected by changes in temperature and oxygen tension, increasing to a maximum 22 beats per minute at 25 C, and decreasing to a minimum 2 beats per minute in anaerobic conditions. Heart rate is reduced (12 beats per minute to 5 beats per minute) on exposure to air. Lutraria exhibits an intermittent pattern of pumping activity. Under normal conditions 35% of the time is spent pumping and this Increases as oxygen is reduced (3.00mls 02/litre) to 65% of the time spent pumping. 15. Under normal conditions the respiratory flow varies between 0.382 litres per hour and 1.023 litres per hxir. Adult Lutraria maintain their ability to burrow, albeit slowly.