Oxygen solubility in seawater: Better fitting equations

Garcia, Herncin E.; Gordon, Louis

doi:10.4319/lo.1992.37.6.1307

Cited by 1,020 publications

(886 citation statements)

References 13 publications

Supporting

Mentioning

829

Contrasting

Unclassified

Order By: Relevance

“…Linear calibration of the microprobe was determined from the electrode readings in air-saturated water above the microbialite and in the anoxic part of the microbialite. Oxygen concentration in air-saturated water was calculated from the solubility equation according to Garcia and Gordon [19].…”

Section: Sampling Sitementioning

confidence: 99%

Irradiance Regulation of Photosynthesis and Respiration in Modern Marine Microbialites Built by Benthic Cyanobacteria in a Tropical Lagoon (New Caledonia)

2005

View full text Add to dashboard Cite

Microbialites are organosedimentary deposits that have built up as a result of the growth and binding of detrital sediment by a benthic microbial community. This study focuses on microbialites built by monospecific populations of cyanobacteria in the south-west lagoon of New Caledonia, where they have been observed down to 20-25 m depth. The aim was to study their photosynthetic and respiratory responses to various light intensities. The Phormidium sp. TK1 microbialite was collected at 19 m depth and the P. crosbyanum (Tilden) microbialite was collected at 0.5 and 13 m depth. Phormidium sp. TK1 showed all the characteristic features of a low-light adapted species. The initial slope of the Photosynthesis versus Irradiance curve for this microbialite was close to the maximum quantum yield indicating an efficient light absorption and utilization at low light. The photosynthesis maximum was located 0.2-0.4 mm below the surface and did not shift with changing light intensity. Respiration rates were low and not enhanced by light; photoinhibition was observed at higher light intensities. In Phormidium crosbyanum (Tilden) microbialites, the photosynthesis maximum shifted downward to lower depths with increasing light, probably as a result of phototactic migration of cyanobacterial filaments, and light-enhanced respiration was observed at light intensities above light saturation. The photosynthetic parameters measured in P. crosbyanum indicate that P. crosbyanum is capable of photo-acclimation at high light intensities. The gross productivity of the different microbialites was comparable to values measured in cyanobacterial stromatolites observed in other shallow environments. However, the microbialites studied here were characterized by a lower respiration / production ratio which indicates a higher growth efficiency.

show abstract

Section: Sampling Sitementioning

confidence: 99%

Irradiance Regulation of Photosynthesis and Respiration in Modern Marine Microbialites Built by Benthic Cyanobacteria in a Tropical Lagoon (New Caledonia)

2005

View full text Add to dashboard Cite

show abstract

“…The temperature and the salinity were kept constant during the incubation time at 20 "C and 35 %, , respectively. Thus, the oxygen concentration in the overlying water was 230 pM (Garcia & Gordon, 1992). The medium in the lower chamber was anoxic, and prepared under a headspace of nitrogen.…”

Section: Methodsmentioning

confidence: 99%

Growth of green sulphur bacteria in experimental benthic oxygen, sulphide, pH and light gradients

et al. 1998

View full text Add to dashboard Cite

The green sulphur bacterium Prosthecochloris aestuarii (strain CE 2401) was cultured in a benthic gradient chamber to study its growth and photosynthetic activity in experimental gradients of oxygen, sulphide and light. An axenic biofilm was obtained within evenly inoculated artificial sediment after 5 weeks of incubation. The phototrophic biofilm was located 2.2-3.5 mm below the sediment surface, i.e. below the maximal penetration depth of oxygen, thus confirming that growth of P. aestuarii was restricted to strictly anoxic sediment layers. The activity was limited by the diffusive flux of sulphide, showing the role of molecular diffusion in growth of this benthic species. Scalar irradiance was attenuated strongly in the biofilm, with distinct attenuation maxima at 750 nm corresponding to bacteriochlorophyll c (Bchl c) absorption and at 800 nm corresponding to bacteriochlorophyll a (Bchl a) absorption. Using radiance attenuation data as a proxy for photopigment contents it was shown that the ratio Bchl a/Bchl c changed with depth. This indicates chromatic adaptation to changing light climates in the sediment. Total sulphide oxidation was estimated from the sulphide fluxes from below into the reaction zone. Measurements of sulphide oxidation as a function of scalar irradiance in the reaction zone showed that anoxygenic photosynthesis of the biofilm was saturated at a scalar irradiance (430-830 nm)>2 μmol photons m-2 s-1.

show abstract

“…These sub-samples were stored in the dark at room-temperature until analysis by membrane inlet mass spectrometry (MIMS) (Tortell 2005). Analytical grade water (18.2 MX Millipore-MilliQ) and seawater (salinity 37) were equilibrated with air at 25°C and used as standards, given temperature and salinity dependence of O 2 solubility (Garcia and Gordon 1992). Oxygen uptake was calculated as the difference in O 2 concentration between incubated and initial samples.…”

Section: Incubation Experiments Bmentioning

confidence: 99%

Oxygen dynamics in shelf seas sediments incorporating seasonal variability

et al. 2017

View full text Add to dashboard Cite

Shelf sediments play a vital role in global biogeochemical cycling and are particularly important areas of oxygen consumption and carbon mineralisation. Total benthic oxygen uptake, the sum of diffusive and faunal mediated uptake, is a robust proxy to quantify carbon mineralisation. However, oxygen uptake rates are dynamic, due to the diagenetic processes within the sediment, and can be spatially and temporally variable. Four benthic sites in the Celtic Sea, encompassing gradients of cohesive to permeable sediments, were sampled over four cruises to capture seasonal and spatial changes in oxygen dynamics. Total oxygen uptake (TOU) rates were measured through a suite of incubation experiments and oxygen microelectrode profiles were taken across all four benthic sites to provide the oxygen penetration depth and diffusive oxygen uptake (DOU) rates. The difference between TOU and DOU allowed for quantification of the fauna mediated oxygen uptake and diffusive uptake. High resolution measurements showed clear seasonal and spatial trends, with higher oxygen uptake rates measured in cohesive sediments compared to the permeable sediment. The significant differences in oxygen dynamics between the sediment types were consistent between seasons, with increasing oxygen consumption during and after the phytoplankton bloom. Carbon mineralisation in shelf sediments is strongly influenced by sediment type and seasonality.

show abstract

Oxygen solubility in seawater: Better fitting equations

Cited by 1,020 publications

References 13 publications

Irradiance Regulation of Photosynthesis and Respiration in Modern Marine Microbialites Built by Benthic Cyanobacteria in a Tropical Lagoon (New Caledonia)

Irradiance Regulation of Photosynthesis and Respiration in Modern Marine Microbialites Built by Benthic Cyanobacteria in a Tropical Lagoon (New Caledonia)

Growth of green sulphur bacteria in experimental benthic oxygen, sulphide, pH and light gradients

Oxygen dynamics in shelf seas sediments incorporating seasonal variability

Contact Info

Product

Resources

About