Respiration and dissolution in sediments of the western Atlantic

We present in situ microelectrode measurements of sediment formation factor and porewater oxygen and pH from six stations in the North Atlantic varying in depth from 2159 to 5380 m. A numerical model of the oxygen data indicates that fluxes of oxygen to the sediments are as much as an order of magnitude higher than benthic chamber flux measurements previously reported in the same area. Model results require dissolution driven by metabolic CO2 production within the sediments to explain the pH data; even at the station with the most undersaturated bottom waters >60% of the calcite dissolution occurs in response to metabolic CO2. Aragonite dissolution alone cannot provide the observed buffering of porewater pH, even at the shallowest station. A sensitivity test of the model that accounts for uncertainties in the bottom water saturation state and the stoichiometry between oxygen consumption and CO2 production during respiration constrains the dissolution rate constant for calcite to between 3 and 30% day**-1, in agreement with earlier in situ determinations of the rate constant. Model results predict that over 35% of the calcium carbonate rain to these sediments dissolves at all stations, confirmed by sediment trap and CaCO3 accumulation data.

Physical characteristics and bacterial production and respiration at stations sampled during 2008 in the eastern Beaufort Sea

Bacterial carbon demand, an important component of ecosystem dynamics in polar waters and sea ice, is a function of both bacterial production (BP) and respiration (BR). BP has been found to be generally higher in sea ice than underlying waters, but rates of BR and bacterial growth efficiency (BGE) are poorly characterized in sea ice. Using melted ice core incubations, community respiration (CR), BP, and bacterial abundance (BA) were studied in sea ice and at the ice-water interface (IWI) in the Western Canadian Arctic during the spring and summer 2008. CR was converted to BR empirically. BP increased over the season and was on average 22 times higher in sea ice as compared with the IWI. Rates in ice samples were highly variable ranging from 0.2 to 18.3 µg C/l/d. BR was also higher in ice and on average ~10 times higher than BP but was less variable ranging from 2.39 to 22.5 µg C/l/d. Given the high variability in BP and the relatively more stable rates of BR, BP was the main driver of estimated BGE (r**2 = 0.97, P < 0.0001). We conclude that microbial respiration can consume a significant proportion of primary production in sea ice and may play an important role in biogenic CO2 fluxes between the sea ice and atmosphere.

Data compilation of marine pelagic organism biomasses, swimming velocities, clearance and respiration rates

Jellyfishes have functionally replaced several overexploited commercial stocks of planktivorous fishes. This is paradoxical, because they use a primitive prey capture mechanism requiring direct contact with the prey, whereas fishes use more efficient visual detection. We have compiled published data to show that, in spite of their primitive life-style, jellyfishes exhibit similar instantaneous prey clearance and respiration rates as their fish competitors and similar potential for growth and reproduction. To achieve this production, they have evolved large, water-laden bodies that increase prey contact rates. Although larger bodies are less efficient for swimming, optimization analysis reveals that large collectors are advantageous if they move through the water sufficiently slowly.

Autotrophic denitrification using sulphur electron donors /

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A study of nitrate respiration in the activated sludge process /

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On the organs of respiration of the oniscidae.

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Catalogue descriptif des principaux appareils balnéaires : appareils d'hydrothérapie de vapeur, de chauffage et de respiration ... /

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Recherches sur le mécanisme de la respiration et sur la circulation du sang : essais... /

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A dissertation on suspended respiration from drowning, hanging and suffocation : in which is recommended a differect mode of treatment to any hitherto pointed out /

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A radical and expeditious cure for a recent catarrhous cough : preceded by some observations on respiration, with occasional and practical remarks on some other diseases of the lungs ; To which is added a chapter on the Vis Vitae, so far as it is concerned in preserving and reinstanting the health of an animal ; Accompanied with some strictures on the treatment of compound fractures /

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A radical and expeditious cure for a recent catarrhous cough : preceded by some observations on respiration, with occasional and practical remarks on some other diseases of the lungs ; To which is added a chapter on the Vis Vitae, so far as it is concerned in preserving and reinstanting the health of an animal ; Accompanied with some strictures on the treatment of compound fractures /

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Dissertation sur le mechanisme et les usages de la respiration : : ouvrage couronné par l'Académie des Sciences, des Belles-Lettres & des Arts de Rouen, le 7 Août 1765 /

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