Seasonal Changes in Oxygen Uptake by Settled Particulate Matter and Sediments in a Marine Bay

1978 ◽  
Vol 35 (12) ◽  
pp. 1621-1628 ◽  
Author(s):  
B. T. Hargrave
Keyword(s):  
Oxygen Consumption ◽  
Particulate Matter ◽  
Oxygen Uptake ◽  
Seasonal Changes ◽  
Sediment Cores ◽  
Late Summer ◽  
Sediment Traps ◽  
Chemical Oxidation ◽  
Organic Content ◽  
Carbon Equivalent

Oxygen consumption by material deposited in sediment traps suspended at different depths in a coastal marine bay was highest during summer. Seasonal changes in respiration (Formalin sensitive oxygen uptake) were significantly correlated with organic content and highest rates on a dry and organic weight basis occurred during summer. There was no consistent depth-related change in oxygen uptake but seasonal changes in respiration were significantly correlated over consecutive 10-m depth intervals between 20 and 60 m. Rates of respiration and chemical oxidation by undisturbed sediment cores from 60 m, which were maximum during late summer, were not related to seasonal changes in temperature or dissolved oxygen concentration. A 1–2-mo delay existed between the deposition of particulate matter with maximum rates of oxygen consumption and maximum oxygen uptake by bottom sediments. Similar seasonal changes and calculation of the carbon equivalent of sediment respiration, however, show that oxidation of settled organic matter is largely complete within the year of deposition. Key words: sedimentation, particulate matter, biological and chemical oxidation, marine sediments

scholarly journals Estimating the effect of burrowing shrimp on deep-sea sediment community oxygen consumption

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3309 ◽  
Author(s):  
Daniel Leduc ◽  
Conrad A. Pilditch
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Continental Slope ◽  
Deep Sea ◽  
Sediment Cores ◽  
Chemical Oxidation ◽  
Community Respiration ◽  
Deep Sea Sediment ◽  
Benthic Respiration ◽  
Infaunal Community

Sediment community oxygen consumption (SCOC) is a proxy for organic matter processing and thus provides a useful proxy of benthic ecosystem function. Oxygen uptake in deep-sea sediments is mainly driven by bacteria, and the direct contribution of benthic macro- and mega-infauna respiration is thought to be relatively modest. However, the main contribution of infaunal organisms to benthic respiration, particularly large burrowing organisms, is likely to be indirect and mainly driven by processes such as feeding and bioturbation that stimulate bacterial metabolism and promote the chemical oxidation of reduced solutes. Here, we estimate the direct and indirect contributions of burrowing shrimp (Eucalastacus cf. torbeni) to sediment community oxygen consumption based on incubations of sediment cores from 490 m depth on the continental slope of New Zealand. Results indicate that the presence of one shrimp in the sediment is responsible for an oxygen uptake rate of about 40 µmol d−1, only 1% of which is estimated to be due to shrimp respiration. We estimate that the presence of ten burrowing shrimp m−2 of seabed would lead to an oxygen uptake comparable to current estimates of macro-infaunal community respiration on Chatham Rise based on allometric equations, and would increase total sediment community oxygen uptake by 14% compared to sediment without shrimp. Our findings suggest that oxygen consumption mediated by burrowing shrimp may be substantial in continental slope ecosystems.

SEASONAL CHANGES IN THE STANDARD RATE OF OXYGEN CONSUMPTION OF FISHES

1964 ◽  
Vol 42 (2) ◽  
pp. 189-194 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Brown Trout ◽  
Seasonal Changes ◽  
Brook Trout ◽  
Spawning Period ◽  
A Value ◽  
Late Fall ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate

The standard rate of oxygen consumption for brook and brown trout acclimated to 10 °C and exposed to natural daylight varied seasonally. For male brook trout, standard oxygen consumption increased from a low of 30 mg/kg hour during March and April to a maximum of 63 mg/kg hour during the late fall spawning period. The standard rates of the females approximated those for males. For male brown trout, standard oxygen uptake increased from a value of approximately 20 mg/kg hour during the winter and spring months to a high of roughly 30 mg/kg hour during the fall spawning period. Little change was observed in the standard oxygen consumption of female brown trout.

Epibenthic Algal Production and Community Respiration in the Sediments of Marion Lake

1969 ◽  
Vol 26 (8) ◽  
pp. 2003-2026 ◽  
Author(s):  
Barry T. Hargrave
Keyword(s):  
Oxygen Consumption ◽  
Particulate Matter ◽  
Oxygen Concentration ◽  
Sediment Cores ◽  
Day Length ◽  
Community Respiration ◽  
Oxygen Production ◽  
Algal Production ◽  
Undisturbed Sediment

Gross epibenthic algal production and benthic community respiration in Marion Lake, British Columbia, were measured during 1968 by following changes in dissolved oxygen over undisturbed sediment cores. No measurable chemical uptake of oxygen occurred during short-term experiments. Multiple regression analyses showed that in situ oxygen production by epibenthic algae was directly related to temperature, light, and community respiration and inversely related to day length. Mean weekly values of these variables were substituted into the regression to estimate annual gross algal production on sediment at various depths in Marion Lake. Photosynthetic efficiency ranged from 0.4 to 3.1% and increased with depth of water over the sediment. Sedimentary chlorophyll was stratified with highest concentrations in the upper few centimeters of sediment which corresponded to the depth of oxygen penetration.Measurements of in situ oxygen consumption showed that community respiration was related to temperature, oxygen concentration, and day length in a curvilinear manner. Oxygen uptake was minimal at midday and increased during the night. A multiple linear regression was derived, after suitable transformations, and mean weekly values of variables substituted to estimate annual community respiration.Bacterial respiration was measured as the difference in total community respiration when antibiotics were added to water over undisturbed sediment cores. Less than 30% of community oxygen consumption was inhibited by antibiotic treatment during the summer, whereas over 45% reduction occurred during the winter. Bacterial respiration was directly related to temperature and showed no significant correlation with oxygen concentration or other variables shown to affect community respiration. Macrofauna respired 33% of the total oxygen consumed by sediment cores during June, and epibenthic algae were estimated to account for 23% of community respiration. Net epibenthic algal production, calculated by correcting gross oxygen production for estimated algal respiration, was 85% of gross production during the summer.Annual carbon flux across the sediment in Marion Lake was estimated by comparing processes of carbon addition and removal. From previous studies, phytoplankton and macrophytes added 0.8 and 18 g C m−2 year−1. Organic particulate matter from the inlet stream, other than macroscopic debris, contributed 143 g C m−2 year−1 and average gross epibenthic algal production was 40 g C m−2 year−1. Community respiration consumed 57 g C m−2 year−1. An additional 143 g C m−2 year−1 was lost as particulate matter in the outlet stream and emerging insects could remove 1.3 g C m−2 year−1. Only 8 g C m−2 was estimated to accumulate below the aerobic surface–sediment layer annually.

scholarly journals No major thermogenic role for (Na+ + K+)-dependent adenosine triphosphatase apparent in hepatocytes from hyperthyroid rats

1982 ◽  
Vol 202 (3) ◽  
pp. 661-665 ◽  
Author(s):  
D G Clark ◽  
M Brinkman ◽  
O H Filsell ◽  
S J Lewis ◽  
M N Berry
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Atpase Activity ◽  
Heat Production ◽  
Adenosine Triphosphatase ◽  
Heat Output ◽  
Liver Parenchymal ◽  
Dependent Atpase ◽  
Parenchymal Cells ◽  
Isolated Liver

(Na+ + K+)-dependent ATPase activity, heat production and oxygen consumption were increased by 59%, 62% and 75% respectively in hepatocytes from tri-iodothyronine-treated rats. Ouabain at concentrations of 1 and 10 mM decreased oxygen uptake by 2-8% in hepatocytes from euthyroid rats and by 5-15% in hepatocytes from hyperthyroid animals. Heat output was decreased by 4-9% with the glycoside in isolated liver parenchymal cells from the control animals and by 11% in the cells from the tri-iodothyronine-treated animals. These results do not support the hypothesis that hepatic (Na+ + K+)-ATPase plays a major role in increased heat production in hepatocytes from hyperthyroid rats.

The effect of the acanthocephalan Pomphorhynchus laevis upon the respiration of its intermediate host, Gammarus pulex

Parasitology ◽  
1974 ◽  
Vol 68 (2) ◽  
pp. 271-284 ◽  
Author(s):  
A. E. Rumpus ◽  
C. R. Kennedy
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Host Population ◽  
Gammarus Pulex ◽  
Multiple Infections ◽  
Pomphorhynchus Laevis ◽  
Respiration Rates ◽  
Physiological Processes ◽  
Stage Of Development ◽  
Host Parasite

The respiration rates of individual Gammarus pulex infected by larval Pomphorhynchus laevis were investigated with particular reference to the stage of development of the host and parasite and to the water temperature. At 20°C the oxygen consumption of Gammarus of all sizes was reduced by an average of 19·3 % by the presence of cystacanths of the parasite, but was unaffected by the presence of acanthellae. It is considered that the small size of this larval stage, in relation to that of its host, is responsible for the failure to detect an effect. Multiple infections did not exert any greater effect upon host respiration than single cystacanths, nor did it appear that the parasite had different effects upon hosts of different sexes. At 10°C no significant differences were observed between the respiration rates of infected and uninfected gammarids. The parasite was probably still depressing the host respiration rate at this temperature, but the oxygen uptake of G. pulex is so low that the differences between infected and uninfected individuals were too small to be detected. The parasite has a direct effect upon the physiological processes of the host, but neither the mechanism of this nor the reasons for the different effects found in different host-parasite systems are yet understood. Despite the pronounced effect of P. laevis on respiration of individual hosts, its effect upon the oxygen consumption of a natural host population is small since only a small proportion of the population carries infections and water temperatures remain below 10°C for over half the year.

Seasonal changes in aerobic fitness indices in elite cyclists

2008 ◽  
Vol 33 (4) ◽  
pp. 735-742 ◽  
Author(s):  
Aldo Sassi ◽  
Franco M. Impellizzeri ◽  
Andrea Morelli ◽  
Paolo Menaspà ◽  
Ermanno Rampinini
Keyword(s):  
Oxygen Consumption ◽  
Aerobic Fitness ◽  
Power Output ◽  
Seasonal Changes ◽  
Peak Power Output ◽  
Time To Exhaustion ◽  
Absolute Maximum ◽  
Maximum Oxygen Consumption ◽  
Main Effect ◽  
Elite Cyclists

The primary purpose of this study was to compare seasonal changes in cycling gross efficiency (GE) and economy (EC) with changes in other aerobic fitness indices. The secondary aim was to assess the relationship between maximum oxygen consumption, GE, and EC among elite cyclists. The relationships of maximum oxygen consumption with GE and EC were studied in 13 cyclists (8 professional road cyclists and 5 mountain bikers). Seasonal changes in GE and EC, predicted time to exhaustion (pTE), maximum oxygen consumption, and respiratory compensation point (RCP) were examined in a subgroup of 8 subjects, before (TREST) and after (TPRECOMP) the pre-competitive winter training, and during the competitive period (TCOMP). GE and EC were assessed during a constant power test at 75% of peak power output (PPO). Significant main effect for time was found for maximum oxygen consumption (4.623 ± 0.675, 4.879 ± 0.727, and 5.010 ± 0.663 L·min–1; p = 0.028), PPO (417.8 ± 46.5, 443.0 ± 48.0, and 455 ± 48 W; p < 0.001), oxygen uptake at RCP (3.866 ± 0.793, 4.041 ± 0.685, and 4.143 ± 0.643 L·min–1; p = 0.049), power output at RCP (330 ± 64, 354 ± 52, and 361 ± 50 W; p < 0.001), and pTE (17 ± 4, 30 ± 8, and 46 ± 17 min; p < 0.001). No significant main effect for time was found in GE (p = 0.097) or EC (p = 0.225), despite within-subject seasonal changes. No significant correlations were found between absolute maximum oxygen consumption and GE (r = –0.276; p = 0.359) or EC (r = –0.328; p = 0.272). However, cyclists with high maximum oxygen consumption values (i.e., over 80 mL·kg–1·min–1), showed low efficiency rates. Despite within-subject seasonal waves in cycling efficiency, changes in GE and EC should not be expected as direct consequence of changes in other maximal and submaximal parameters of aerobic fitness (i.e., maximum oxygen consumption and RCP).

Lipid accumulation by migrating monarch butterflies (Danaus plexippus L.)

1993 ◽  
Vol 71 (1) ◽  
pp. 76-82 ◽  
Author(s):  
David L. Gibo ◽  
Jody A. McCurdy
Keyword(s):  
Lipid Accumulation ◽  
Seasonal Changes ◽  
Late Phase ◽  
Danaus Plexippus ◽  
Late Summer ◽  
Dry Mass ◽  
Middle Phase ◽  
Southern Ontario ◽  
Lipid Mass ◽  
Peak Abundance

The migration of Danaus plexippus during the late summer in southern Ontario in 1986 lasted for about 8 weeks and consisted of three phases, an early phase characterized by increasing abundance, a middle phase of peak abundance, and a late phase characterized by declining abundance. As the season progressed, systematic changes were observed in wet mass, dry mass, lean dry mass, lipid mass, and forewing length. Wet mass, lean dry mass, and forewing length were similar for early- and middle-phase individuals, but declined in late-phase migrants. Lipid mass peaked in the middle phase of the migration and then declined abruptly in the late phase. Dry mass also peaked in the middle phase, reflecting changes in lipid mass and lean dry mass. We hypothesize that the observed changes in lipid mass and lean dry mass over the 8 weeks resulted from changes in population structure as well as seasonal changes in the weather, and in availability of nectar. Opposing conclusions reached in previous studies of lipid accumulation in D. plexippus are probably the result of failure to control for phase of migration.

scholarly journals Oxygen uptake during mineralization of photosynthesized carbon from phytoplankton of the Barra Bonita Reservoir: a mesocosm study

2008 ◽  
Vol 68 (1) ◽  
pp. 115-122 ◽  
Author(s):  
MB. Cunha-Santino ◽  
SP. Gouvêa ◽  
I. Bianchini Jr ◽  
AAH. Vieira
Keyword(s):  
Electrical Conductivity ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Dissolved Oxygen ◽  
Water Samples ◽  
Microbial Respiration ◽  
Co2 Concentration ◽  
Ph Values ◽  
Organic Products ◽  
Aulacoseira Granulata

This study aimed to discuss and describe the oxygen consumption during aerobic mineralization of organic products (cells and excretion products) from five unialgal cultures: Cryptomonas sp., Microcystis aeruginosa, Anabaena spiroides, Thalassiosira sp. and Aulacoseira granulata. These species were isolated from Barra Bonita reservoir (22º 29’ S and 48º 34’ W) and cultivated in the laboratory. From each culture, two decomposition chambers were prepared; each chamber contained about 130 mg.L-1 of carbon from water samples of the reservoir. The chambers were aerated and incubated in the dark at 20.0 ºC. The concentration of dissolved oxygen, pH values and electrical conductivity of the solutions were determined during a period of 10 days. The results indicated increases in oxygen consumption for all the solutions studied and also for electrical conductivity. The pH values presented a decreasing tendency throughout the experiment. Oxygen consumption varied from 43 (Aulacoseira granulata chamber) to 345 mg O2 g-1 C (Anabaena spiroides chamber). Decrease in pH values was probably due to increase in CO2 concentration from microbial respiration. Increase in electrical conductivity might be due to the liberation of ions during decomposition. The results demonstrate the potentiality of the studied genera in influencing oxygen availability followed by a die-off event. It also indicates the possibility of changing of the electrical conductivity and pH values in the water column due the aerobic algae mineralization.

scholarly journals The Paths of the Suspended Particulate Inorganic and Organic Matter in a Small Urban Estuary: The Aarhus Harbour Estuary

1986 ◽  
Vol 17 (1) ◽  
pp. 31-46 ◽  
Author(s):  
K. B. Kronvang ◽  
C. Christiansen
Keyword(s):  
Organic Matter ◽  
Particulate Matter ◽  
Organic Content ◽  
Temporal And Spatial Distribution ◽  
Urban Estuary ◽  
Inorganic Matter ◽  
Organic Sediment ◽  
Suspended Particulate ◽  
Good Agreement ◽  
Inorganic And Organic

The nverine supply of suspended inorganic and organic sediment, its temporal and spatial distribution and its exchange with the bay, were estimated for an urban estuary (Aarhus Harbour Estuary, Denmark) during 1983-84. The river supplies high levels of particulate matter to the estuary. Export from the estuary averages one fifth of the river introduced particulate matter resulting in the accumulation of terrigenous material in the estuary. River discharge determines whether the high depletion of particulate matter in the upper estuary follows an exponential(flocculation) or a lineary curve (dilution). Preferential deposition of organic as opposed to inorganic matter in the upper estuary depletes the particulate matter of organic matter and associated pollutants. The estuary is divided into three depositional zones identified on the basis of sediment activity, grain-size and organic content. A sediment budget is precented for the estuary. Good agreement is shown between the actually dredged sediment quantity and the mass to sedimentation from the budget.

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