Control of net community production by microbial community respiration at Station ALOHA

2018 ◽  
Vol 184 ◽  
pp. 28-35
Author(s):  
Sandra Martínez-García ◽  
Robert R. Bidigare ◽  
Daniela A. del Valle ◽  
Laurie W. Juranek ◽  
David P. Nicholson ◽  
...  
Keyword(s):  
Microbial Community ◽  
Community Respiration ◽  
Net Community Production ◽  
Station Aloha ◽  
Community Production

scholarly journals Rates and drivers of Red Sea plankton community metabolism

2018 ◽  
Author(s):  
Daffne C. López-Sandoval ◽  
Katherine Rowe ◽  
Paloma Carillo-de-Albonoz ◽  
Carlos M. Duarte ◽  
Susana Agusti
Keyword(s):  
Red Sea ◽  
Gross Primary Production ◽  
Environmental Drivers ◽  
Community Respiration ◽  
Net Community Production ◽  
Chl A ◽  
Warm Environment ◽  
Increasing Temperature ◽  
Community Production ◽  
Planktonic Communities

Abstract. Resolving the environmental drivers shaping planktonic communities is fundamental to understanding their variability, present and future, across the ocean. More specifically, resolving the temperature-dependence of planktonic communities in low productive waters is essential to predict the response of marine ecosystems to warming scenarios, as ocean warming leads to oligotrophication of the subtropical ocean. Here we quantified plankton metabolic rates along the Red Sea, a unique oligotrophic and warm environment, and analysed the drivers that regulate gross primary production (GPP), community respiration (CR) and the net community production (NCP). The study was conducted on six oceanographic surveys following a north-south transect along Saudi Arabian coasts. Our findings revealed that Chl-a specific GPP and CR rates increased with increasing temperature (R2 = 0.41 and 0.19, respectively, P 

scholarly journals Ecosystem metabolism in a temporary Mediterranean marsh (Doñana National Park, SW Spain)

2010 ◽  
Vol 7 (4) ◽  
pp. 6495-6521 ◽  
Author(s):  
O. Geertz-Hansen ◽  
C. Montes ◽  
C. M. Duarte ◽  
K. Sand-Jensen ◽  
N. Marbá ◽  
...  
Keyword(s):  
National Park ◽  
Submerged Macrophytes ◽  
Community Respiration ◽  
Production Rates ◽  
Doñana National Park ◽  
Net Community Production ◽  
Sw Spain ◽  
Respiration Rates ◽  
R Ratio ◽  
Community Production

Abstract. The metabolic balance of the open waters supporting submerged macrophytes of the Doñana marsh (SW Spain) was investigated in spring, when community production is highest. The marsh community was net autotrophic with net community production rates averaging 0.61 g C m−2 d−1, and gross production rates exceeding community respiration rates by, on average, 43%. Net community production increased greatly with increasing irradiance, with the threshold irradiance for communities to become net autotrophic being 42 to 255 μE m−2 s−1, below which communities became net heterotrophic. Examination of the contributions of the benthic and the pelagic compartments showed the pelagic compartment to be strongly heterotrophic (average P/R ratio = 0.27), indicating that the metabolism of the pelagic compartment is strongly subsidised by excess organic carbon produced in the strongly autotrophic benthic compartment (average P/R = 1.58).

scholarly journals Patterns in planktonic metabolism in the Mediterranean Sea

2009 ◽  
Vol 6 (12) ◽  
pp. 3081-3089 ◽  
Author(s):  
A. Regaudie-de-Gioux ◽  
R. Vaquer-Sunyer ◽  
C. M. Duarte
Keyword(s):  
Mediterranean Sea ◽  
Gross Primary Production ◽  
Western Mediterranean ◽  
Early Summer ◽  
Late Spring ◽  
Community Respiration ◽  
Net Community Production ◽  
R Ratio ◽  
The Mediterranean ◽  
Community Production

Abstract. Planktonic gross community production (GPP), net community production (NCP) and community respiration (CR) across the Mediterranean Sea was examined in two cruises, Thresholds 2006 and 2007, each crossing the Mediterranean from West to East to test for consistent variation along this longitudinal gradient in late spring to early summer. GPP averaged 2.4±0.4 mmol O2 m−3 d−1, CR averaged 3.8±0.5 mmol O2 m−3 d−1, and NCP averaged – 0.8±0.6 mmol O2 m−3 d−1 across the studied sections, indicative of a tendency for a net heterotrophic metabolism in late spring to early summer, prevalent across studied sections of the Mediterranean Sea as reflected in 70% of negative NCP estimates. The median P/R ratio was 0.6, also indicating a strong prevalence of heterotrophic communities (P/R<1) along the studied sections of the Mediterranean Sea. The communities tended to be net heterotrophic (i.e. P/R<1) at GPP less than 2.8 mmol O2 m−3 d−1. The Western Mediterranean tended to support a higher gross primary production and community respiration than the Eastern basin did, but these differences were not statistically significant (t-test, p>0.05). The net heterotrophy of the studied sections of the Mediterranean Sea indicates that allochthonous carbon should be important to subsidise planktonic metabolism during the late spring.

Impacts of the non-native alga Sargassum horneri on benthic community production in a California kelp forest

2020 ◽  
Vol 637 ◽  
pp. 45-57 ◽  
Author(s):  
GH Sullaway ◽  
MS Edwards
Keyword(s):  
Temporal Dynamics ◽  
Kelp Forest ◽  
Fold Increase ◽  
Sargassum Horneri ◽  
Community Respiration ◽  
Ecosystem Change ◽  
Rocky Reef ◽  
Net Community Production ◽  
Benthic Chambers ◽  
Community Production

The arrival of Sargassum horneri throughout the Southern California Bight and the Baja Peninsula has raised concern regarding kelp forest resilience and ecosystem function following the invasion of this non-native species. To understand how S. horneri impacts native algal abundance and community production, we removed S. horneri from experimental plots over a period of 11 mo. We measured impacts on native algal communities and community productivity using SCUBA surveys and benthic chambers equipped with oxygen, temperature, and light sensors. We observed a nearly 4-fold increase in recruitment of Macrocystis pyrifera and a 9-fold increase in adult M. pyrifera stipe density in S. horneri removal plots, but no discernable changes in net community production among treatments. We found ephemeral increases in gross community production and community respiration in the non-removal plots that coincided with periods of peak S. horneri biomass. To understand the temporal dynamics of community production, we deployed benthic chambers across a rocky reef dominated by S. horneri. Here, temporal variation in community production was most strongly related to corresponding variation in water temperature and changes in S. horneri biomass related to its annual lifecycle. Overall, our study indicates that S. horneri presence contributed to ephemeral increases in gross community production and community respiration, but it did not affect net community production. Moreover, S. horneri removal can lead to increases in native algal abundances given favorable abiotic conditions. We suggest that S. horneri thrives in a disturbed ecosystem rather than being a driver of ecosystem change.

scholarly journals Metabolic balance of a plankton community in a pelagic water of a northern high latitude fjord in response to increased <i>p</i>CO<sub>2</sub>

2012 ◽  
Vol 9 (8) ◽  
pp. 11013-11039 ◽  
Author(s):  
T. Tanaka ◽  
S. Alliouane ◽  
R. G. J. Bellerby ◽  
J. Czerny ◽  
A. de Kluijver ◽  
...  
Keyword(s):  
High Latitude ◽  
Phase 1 ◽  
Plankton Community ◽  
Nutrient Addition ◽  
Community Respiration ◽  
Phase 3 ◽  
Net Community Production ◽  
Clear Trend ◽  
Northern High Latitude ◽  
Community Production

Abstract. The effect of ocean acidification on the balance between gross community production (GCP) and community respiration (CR) (i.e. net community production, NCP) of plankton communities was investigated in summer 2010 in Kongsfjorden, West of Svalbard. Surface water, which was characterized by low concentrations of dissolved inorganic nutrients and chlorophyll, was enclosed in 9 mesocosms and subjected to 8 pCO2 levels (2 replicated controls and 7 enhanced pCO2 treatments) for one month. Nutrients were added to all mesocosms on day 13 of the experiment, and thereafter increase of chlorophyll (index of phytoplankton biomass) was provoked in all mesocosms. No clear trend in response to increasing pCO2 was found in the daily values of NCP, CR, and GCP. For further analysis, these parameters were cumulated for the following three periods: phase 1: end of CO2 manipulation until nutrient addition (t4 to t13); phase 2: nutrient addition until the second chlorophyll minimum (t14 to t21); phase 3: the second chlorophyll minimum until the end of this study (t22 to t28). Significant response was detected as a decrease of NCP with increasing pCO2 during phase 3. CR was relatively stable throughout the experiment in all mesocosms. As a result, the cumulative GCP significantly decreased with increasing pCO2 during phase 3. After the nutrient addition, the ratios of cumulative NCP to cumulative consumption of NO3 and PO4 showed significant decrease during phase 3 with increasing pCO2. The results suggest that elevated pCO2 influenced cumulative NCP and stoichiometric C and nutrient coupling of the plankton community in a high latitude fjord only for a limited period. However provided that there were some differences or weak correlations between NCP data based on different methods in the same experiment, this conclusion should be taken with caution.

scholarly journals Effect of increased <i>p</i>CO<sub>2</sub> on the planktonic metabolic balance during a mesocosm experiment in an Arctic fjord

2013 ◽  
Vol 10 (1) ◽  
pp. 315-325 ◽  
Author(s):  
T. Tanaka ◽  
S. Alliouane ◽  
R. G. B. Bellerby ◽  
J. Czerny ◽  
A. de Kluijver ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Phase 1 ◽  
Nutrient Addition ◽  
Community Respiration ◽  
Phase 3 ◽  
Net Community Production ◽  
Clear Trend ◽  
Dissolved Inorganic Nutrients ◽  
Low Concentrations ◽  
Community Production

Abstract. The effect of ocean acidification on the balance between gross community production (GCP) and community respiration (CR) (i.e., net community production, NCP) of plankton communities was investigated in summer 2010 in Kongsfjorden, west of Svalbard. Surface water, which was characterized by low concentrations of dissolved inorganic nutrients and chlorophyll a (a proxy of phytoplankton biomass), was enclosed in nine mesocosms and subjected to eight pCO2 levels (two replicated controls and seven enhanced pCO2 treatments) for one month. Nutrients were added to all mesocosms on day 13 of the experiment, and thereafter increase of chlorophyll a was provoked in all mesocosms. No clear trend in response to increasing pCO2 was found in the daily values of NCP, CR, and GCP. For further analysis, these parameters were cumulated for the following three periods: phase 1 – end of CO2 manipulation until nutrient addition (t4 to t13); phase 2 – nutrient addition until the second chlorophyll a minimum (t14 to t21); phase 3 – the second chlorophyll a minimum until the end of this study (t22 to t28). A significant response was detected as a decrease of NCP with increasing pCO2 during phase 3. CR was relatively stable throughout the experiment in all mesocosms. As a result, the cumulative GCP significantly decreased with increasing pCO2 during phase 3. After the nutrient addition, the ratios of cumulative NCP to cumulative consumption of NO3 and PO4 showed a significant decrease during phase 3 with increasing pCO2. The results suggest that elevated pCO2 influenced cumulative NCP and stoichiometric C and nutrient coupling of the plankton community in a high-latitude fjord only for a limited period. However provided that there were some differences or weak correlations between NCP data based on different methods in the same experiment, this conclusion should be taken with caution.

scholarly journals Consequences of respiration in the light on the determination of production in pelagic systems

2007 ◽  
Vol 4 (1) ◽  
pp. 105-114 ◽  
Author(s):  
O. Pringault ◽  
V. Tassas ◽  
E. Rochelle-Newall
Keyword(s):  
Primary Production ◽  
Dark Respiration ◽  
Gross Primary Production ◽  
Community Respiration ◽  
Metabolic Balance ◽  
Net Community Production ◽  
Respiration Rates ◽  
Seawater Samples ◽  
Community Production

Abstract. Oxygen microprobes were used to estimate Community Respiration (R), Net Community Production (NCP) and Gross Primary Production (GPP) in coastal seawater samples. Using this highly stable and reproducible technique to measure oxygen change during alternating dark and light periods, we show that respiration in the light could account for up to 640% of respiration in the dark. The light enhanced dark respiration can remain elevated for several hours following a 12 h period of illumination. Not including Rlight into calculations of production leads to an underestimation of GPP, which can reach up to 650% in net heterotrophic systems. The production: respiration (P:R) ratio is in turn affected by the higher respiration rates and by the underestimation of GPP. While the integration of Rlight into the calculation of P:R ratio does not change the metabolic balance of the system, it decreases the observed tendency, thus net autotrophic systems become less autotrophic and net heterotrophic systems become less heterotrophic. As a consequence, we propose that efforts have to be focused on the estimation and the integration of Rlight into the determination of GPP and R for a better understanding of the aquatic carbon cycle.

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