scholarly journals Ballast minerals and the sinking carbon flux in the ocean: carbon-specific respiration rates and sinking velocities of macroscopic organic aggregates (marine snow)

2010 ◽  
Vol 7 (3) ◽  
pp. 3335-3364 ◽  
Author(s):  
M. H. Iversen ◽  
H. Ploug
Keyword(s):  
Respiration Rate ◽  
Skeletonema Costatum ◽  
Aggregate Size ◽  
Respiration Rates ◽  
Carbon Remineralization ◽  
Marine Aggregates ◽  
Organic Carbon Fluxes ◽  
Ocean Carbon ◽  
Sinking Velocities ◽  
Sinking Velocity

Abstract. Recent observations have shown that fluxes of ballast minerals (calcium carbonate, opal, and lithogenic material) and organic carbon fluxes are closely correlated in the bathypelagic zones of the ocean. Hence it has been hypothesized that incorporation of biogenic minerals within marine aggregates could either protect the organic matter from decomposition and/or increase the sinking velocity via ballasting of the aggregates. Here we present the first combined data on size, sinking velocity, carbon-specific respiration rate, and composition measured directly in three aggregate types; Emiliania huxleyi aggregates (carbonate ballasted), Skeletonema costatum aggregates (opal ballasted), and aggregates made from a mix of both E. huxleyi and S. costatum (carbonate and opal ballasted). Overall average carbon-specific respiration rate was ~0.13 d−1 and did not vary with aggregate type and size. Ballasting from carbonate resulted in 2- to 2.5-fold higher sinking velocities than aggregates ballasted by opal. We compiled literature data on carbon-specific respiration rate and sinking velocity measured in aggregate of different composition and sources. Compiled carbon-specific respiration rates (including this study) vary between 0.08 d−1 and 0.20 d−1. Sinking velocity increases with increasing aggregate size within homogeneous sources of aggregates. When compared across different particle and aggregate sources, however, sinking velocity appeared to be independent of particle or aggregate size. The calculated carbon remineralization length scale due to microbial respiration and sinking velocity of mm-large marine aggregates was higher for calcite ballasted aggregates as compared to opal-ballasted aggregates. It varied between 0.0002 m−1 and 0.0030 m−1, and decreased with increasing aggregate size.

scholarly journals Ballast minerals and the sinking carbon flux in the ocean: carbon-specific respiration rates and sinking velocity of marine snow aggregates

2010 ◽  
Vol 7 (9) ◽  
pp. 2613-2624 ◽  
Author(s):  
M. H. Iversen ◽  
H. Ploug
Keyword(s):  
Respiration Rate ◽  
Skeletonema Costatum ◽  
Aggregate Size ◽  
Respiration Rates ◽  
Marine Aggregates ◽  
Organic Carbon Fluxes ◽  
Ocean Carbon ◽  
Sinking Velocities ◽  
Sinking Velocity ◽  
Combined Data

Abstract. Recent observations have shown that fluxes of ballast minerals (calcium carbonate, opal, and lithogenic material) and organic carbon fluxes are closely correlated in the bathypelagic zones of the ocean. Hence it has been hypothesized that incorporation of biogenic minerals within marine aggregates could either protect the organic matter from decomposition and/or increase the sinking velocity via ballasting of the aggregates. Here we present the first combined data on size, sinking velocity, carbon-specific respiration rate, and composition measured directly in three aggregate types; Emiliania huxleyi aggregates (carbonate ballasted), Skeletonema costatum aggregates (opal ballasted), and aggregates made from a mix of both E. huxleyi and S. costatum (carbonate and opal ballasted). Overall average carbon-specific respiration rate was ~0.13 d−1 and did not vary with aggregate type and size. Ballasting from carbonate resulted in 2- to 2.5-fold higher sinking velocities than those of aggregates ballasted by opal. We compiled literature data on carbon-specific respiration rate and sinking velocity measured in aggregates of different composition and sources. Compiled carbon-specific respiration rates (including this study) vary between 0.08 d−1 and 0.20 d−1. Sinking velocity increases with increasing aggregate size within homogeneous sources of aggregates. When compared across different particle and aggregate sources, however, sinking velocity appeared to be independent of particle or aggregate size. The carbon-specific respiration rate per meter settled varied between 0.0002 m−1 and 0.0030 m−1, and decreased with increasing aggregate size. It was lower for calcite ballasted aggregates as compared to that of similar sized opal ballasted aggregates.

scholarly journals Temperature effects on carbon-specific respiration rate and sinking velocity of diatom aggregates – potential implications for deep ocean export processes

2013 ◽  
Vol 10 (6) ◽  
pp. 4073-4085 ◽  
Author(s):  
M. H. Iversen ◽  
H. Ploug
Keyword(s):  
Respiration Rate ◽  
Deep Ocean ◽  
Sediment Traps ◽  
Average Particle ◽  
Data Set ◽  
Direct Measurements ◽  
Ocean Sediment ◽  
Influence Of Temperature On ◽  
Ocean Carbon ◽  
Sinking Velocity

Abstract. Most deep ocean carbon flux profiles show low and almost constant fluxes of particulate organic carbon (POC) in the deep ocean. However, the reason for the non-changing POC fluxes at depths is unknown. This study presents direct measurements of formation, degradation, and sinking velocity of diatom aggregates from laboratory studies performed at 15 °C and 4 °C during a three-week experiment. The average carbon-specific respiration rate during the experiment was 0.12 ± 0.03 at 15 °C, and decreased 3.5-fold when the temperature was lowered to 4 °C. No direct influence of temperature on aggregate sinking speed was observed. Using the remineralisation rate measured at 4 °C and an average particle sinking speed of 150 m d−1, calculated carbon fluxes were similar to those collected in deep ocean sediment traps from a global data set, indicating that temperature plays a major role for deep ocean fluxes of POC.

scholarly journals Temperature effects on carbon-specific respiration rate and sinking velocity of diatom aggregates – potential implications for deep ocean export processes

2013 ◽  
Vol 10 (1) ◽  
pp. 371-399 ◽  
Author(s):  
M. H. Iversen ◽  
H. Ploug
Keyword(s):  
Respiration Rate ◽  
Deep Ocean ◽  
Sediment Traps ◽  
Average Particle ◽  
Data Set ◽  
Direct Measurements ◽  
Ocean Sediment ◽  
Influence Of Temperature On ◽  
Ocean Carbon ◽  
Sinking Velocity

Abstract. Most deep ocean carbon flux profiles show low and almost constant fluxes of particulate organic carbon (POC) in the deep ocean. However, the reason for the seemingly non-changing POC fluxes at depths is unknown. This study presents direct measurements of formation, degradation, and sinking velocity of diatom aggregates from laboratory studies performed at 15 °C and 4 °C during a three week experiment. The average carbon-specific respiration rate during the experiment was 0.12 ± 0.03 at 15 °C, and decreased 3.5-fold when the temperature was lowered to 4 °C. No direct influence of temperature on aggregate sinking speed was observed. Using the remineralisation rate measured at 4 °C and an average particle sinking speed of 150 m d−1, calculated carbon fluxes were similar to those collected in deep ocean sediment traps from a global data set, indicating that temperature plays a major role for deep ocean fluxes of POC.

EFFECT OF VARIOUS HORMONES ON THE KIDNEY RESPIRATION RATES IN THE CUTTHROAT TROUT (SALMO CLARKI CLARKI)

1960 ◽  
Vol XXXIII (III) ◽  
pp. 428-436 ◽  
Author(s):  
W. N. Holmes
Keyword(s):  
Single Dose ◽  
Respiration Rate ◽  
Cutthroat Trout ◽  
Adaptive Mechanism ◽  
Respiration Rates ◽  
Salmo Clarki

ABSTRACT Relatively large doses of vasopressin administered intraperitoneally to the trout significantly enhanced the kidney respiration rate. In contrast to vasopressin a single dose of oxytocin depressed the kidney Qo2 value. This depression continued throughout the observed 24 hour period after injection. Cortisol enhanced the kidney Qo2 values significantly and to a greater extent than vasopressin. These results are discussed in relation to possible adaptive mechanism in euryhaline species of teleosts.

Validation of On-line Respiration Meter and its Applications by Computer Simulation

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Respiration Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Mass Balances ◽  
Short Term ◽  
Respiration Rates ◽  
On Line ◽  
Made In

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.

Decrease in soil microbial activity and biomasses owing to nitrogen amendments

1983 ◽  
Vol 29 (11) ◽  
pp. 1500-1506 ◽  
Author(s):  
B. Söderström ◽  
E. Bååth ◽  
B. Lundgren
Keyword(s):  
Respiration Rate ◽  
Laboratory Experiments ◽  
Coniferous Forest ◽  
Soil Microbial Activity ◽  
Urea Treatment ◽  
Soil Microbial ◽  
Respiration Rates ◽  
Nitrate Addition ◽  
Transitory Effect ◽  
Forest Podzols

Microbial biomass and soil respiration rate decreased after application of 150 kg NH4NO3–N∙ha−1 to different coniferous forest podzols. The decrease was already found 3 months after fertilization and was still evident after 3–5 years. Changes in pH, organic matter, or water content in the soils could not explain the decreases. In laboratory experiments, several unfertilized forest soils were treated with 2 mg of NH4NO3–N or of urea–nitrogen∙g wet soil−1. The ammonium nitrate addition resulted in severe depressions of the respiration rates during and up to 175 days of incubation and the decrease was evident after about 1 week. The urea treatment initially increased the respiration rate of the soils, but this appeared to be a transitory effect.

Stress level in wild harbour porpoises (Phocoena phocoena) during satellite tagging measured by respiration, heart rate and cortisol

2009 ◽  
Vol 89 (5) ◽  
pp. 885-892 ◽  
Author(s):  
I.G. Eskesen ◽  
J. Teilmann ◽  
B.M. Geertsen ◽  
G. Desportes ◽  
F. Riget ◽  
...  
Keyword(s):  
Heart Rate ◽  
Respiration Rate ◽  
Serum Cortisol ◽  
Phocoena Phocoena ◽  
Heart Rates ◽  
Stress Effects ◽  
Respiration Rates ◽  
Stressed Animal ◽  
Cortisol Levels ◽  
Satellite Tagging

During satellite tagging of harbour porpoises (Phocoena phocoena), heart rate, respiration rate and cortisol value were measured to evaluate stress effects during handling and tagging. Respiration rates were obtained using video recordings, heart rates were recorded and serum cortisol levels were analysed from blood samples. Differences in heart rates, respiration rates and cortisol levels before and during the tagging events were investigated. An overall significant decrease of 31.5% in respiration rate was found during the tagging event period, while mature porpoises respired significantly more often than immature individuals. Though significant differences in heart rates were found for some individuals, no general significant change for all animals was detected. We found no correlation between cortisol concentration and either heart rate or respiration rate, nor did we find any relationships between cortisol and month of year, sex and body length. As high individual variations occurred in response to tagging of harbour porpoises, it is not possible to give general advice based on the factors investigated, on how to reduce stress during handling. However, pouring water over the animal and lowering it into the water seem to stabilize a stressed animal. Therefore, general precaution and individual judgement based on experience is essential when handling wild harbour porpoises.

scholarly journals The Influence of Plankton Community Structure on Sinking Velocity and Remineralization Rate of Marine Aggregates

2019 ◽  
Vol 33 (8) ◽  
pp. 971-994 ◽  
Author(s):  
L. T. Bach ◽  
P. Stange ◽  
J. Taucher ◽  
E. P. Achterberg ◽  
M. Algueró‐Muñiz ◽  
...  
Keyword(s):  
Community Structure ◽  
Plankton Community ◽  
Marine Aggregates ◽  
Plankton Community Structure ◽  
Sinking Velocity

scholarly journals The role of predator removal by fishing on ocean carbon dynamics

2021 ◽  
Author(s):  
Rick Stafford ◽  
Zach Boakes ◽  
Alice Hall ◽  
Georgia Jones
Keyword(s):  
Predatory Fish ◽  
Fish Biomass ◽  
Predator Removal ◽  
High Productivity ◽  
Respiration Rates ◽  
Total Fish ◽  
Ocean Carbon ◽  
Global Carbon ◽  
Phytoplankton Photosynthesis

Abstract The ocean is a net sequester of carbon dioxide, predominantly through low biomass, high productivity phytoplankton photosynthesis. Selective removal of predatory fish through extractive fishing alters the community structure of the ocean, with an increased biomass of more productive, low trophic level fish and higher overall respiration rates, despite possible decreases in total fish biomass. High pressure fishing on predators may result in as much as a 19% increase in respiration from fish communities and could prove highly significant in global carbon budgets.

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