Determinants of pelagic metabolism in the Timor Sea during the inter-monsoon period

2011 ◽  
Vol 62 (2) ◽  
pp. 130 ◽  
Author(s):  
A. D. McKinnon ◽  
J. H. Carleton ◽  
S. Duggan
Keyword(s):  
Gross Primary Production ◽  
Vertical Mixing ◽  
Community Respiration ◽  
New Production ◽  
Net Community Production ◽  
Monsoon Period ◽  
Hydrocarbon Seeps ◽  
Timor Sea ◽  
Waves And Tides ◽  
High Production

The Timor Sea is a major conduit of the Indonesian Throughflow characterised by large internal waves and tides. To ascertain whether these result in high pelagic productivity, we conducted experiments to determine the metabolic balance between net community production (NCP) and community respiration (CR) on the Sahul Shelf, the Sahul Shoals and the Yampi Shelf, an area of active hydrocarbon seeps. The barrier to vertical mixing of subthermocline nutrients represented by the halocline allowed new production to dominate in March 2004, whereas production in June 2005 depended on recycled nutrients. CR was correlated with dissolved organic carbon (DOC) in 2004, but with chlorophyll in 2005, suggesting that respiration was dominated by microheterotrophs in 2004 but by autotrophs in 2005. Overall, area-specific CR averaged 120 ± 92 (s.d.), 101 ± 52 and 61 ± 6 mmol O2 m–2 day–1, NCP averaged 109 ± 85 (s.d.), 32 ± 41 and 57 ± 10 mmol O2 m–2 day–1, and average gross primary production (= CR+NCP) : R ratios were 1.9, 1.4 and 1.9 on the shelf, at the Sahul Shoals and the Yampi Shelf, respectively. We suggest that differences in water column structure and internal wave activity drive intermittent high production events in a predominantly oligotrophic sea.

scholarly journals Temperature dependence of planktonic metabolism in the subtropical North Atlantic Ocean

2014 ◽  
Vol 11 (16) ◽  
pp. 4529-4540 ◽  
Author(s):  
L. S. García-Corral ◽  
E. Barber ◽  
A. Regaudie-de-Gioux ◽  
S. Sal ◽  
J. M. Holding ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Temperature Dependence ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Gross Primary Production ◽  
Activation Energies ◽  
Community Respiration ◽  
Metabolic Rates ◽  
Net Community Production ◽  
Different Seasons

Abstract. The temperature dependence of planktonic metabolism in the subtropical North Atlantic Ocean was assessed on the basis of measurements of gross primary production (GPP), community respiration (CR) and net community production (NCP), as well as experimental assessments of the response of CR to temperature manipulations. Metabolic rates were measured at 68 stations along three consecutive longitudinal transects completed during the Malaspina 2010 Expedition, in three different seasons. Temperature gradients were observed in depth and at basin and seasonal scale. The results showed seasonal variability in the metabolic rates, the highest rates being observed during the spring transect. The overall mean integrated GPP / CR ratio was 1.39 ± 0.27 decreasing from winter to summer, and the NCP for the subtropical North Atlantic Ocean during the cruises exhibits net autotrophy (NCP > 0) in about two-thirds (66%) of the total sampled communities. Also, we reported the activation energies describing the temperature dependence of planktonic community metabolism, which was generally higher for CR than for GPP in the subtropical North Atlantic Ocean, as the metabolic theory of ecology predicts. Furthermore, we made a comparison of activation energies describing the responses to in situ temperature in the field (EaCR = 1.64 ± 0.36 eV) and those derived experimentally by temperature manipulations (EaCR = 1.45 ± 0.6 eV), which showed great consistency.

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 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.

scholarly journals Annual plankton community metabolism in estuarine and coastal waters in Perth (Western Australia)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5081 ◽  
Author(s):  
Susana Agusti ◽  
Lorena Vigoya ◽  
Carlos Manuel Duarte
Keyword(s):  
Organic Matter ◽  
Western Australia ◽  
Environmental Variability ◽  
Gross Primary Production ◽  
Marine Ecosystem ◽  
Community Respiration ◽  
Metabolic Rates ◽  
Metabolic Balance ◽  
Net Community Production ◽  
R Ratio

The planktonic metabolic balance that is the balance between gross primary production (GPP) and community respiration (CR) was determined in Matilda Bay (estuarine) and Woodman Point (coastal) in Perth, Western Australia. The rates of net community production (NCP = GPP – CR) and the ratio between GPP and CR (P/R) were assessed to evaluate whether the metabolic balance in the two coastal locations tends to be net autotrophic (production exceeding community respiration) or net heterotrophic (respiration exceeding production). We also analyzed environmental variability by measuring temperature, salinity, and nutrients and chlorophyll a concentration. Samples were collected biweekly from March 2014 to March 2015. During the study period the metabolic rates were three times higher in Matilda Bay than in Woodman Point. The predominant metabolism was net autotrophic at both sites with P/R ratios >1 in the majority of the sampling dates. In Matilda Bay, the metabolic rates were negatively correlated with salinity denoting river dynamics influence, and positively with chlorophyll a. In Woodman Point only the GPP was positively correlated with chlorophyll a. The positive correlation between P/R ratio and GPP in Matilda Bay and the positive correlations between the metabolic rates and chlorophyll a suggest that factors controlling autotrophic processes are modulating the planktonic metabolic balance in the coastal marine ecosystem in Perth. Significant correlations were found between CR and GPP-standardized to chlorophyll a and water temperature. The net autotrophic metabolic balance indicates that in both ecosystems planktonic communities are acting as a sink of CO2 and as a source of organic matter and oxygen to the system and are able to export organic matter to other ecosystems.

scholarly journals Rates and drivers of Red Sea plankton community metabolism

2019 ◽  
Vol 16 (15) ◽  
pp. 2983-2995 ◽  
Author(s):  
Daffne C. López-Sandoval ◽  
Katherine Rowe ◽  
Paloma Carillo-de-Albonoz ◽  
Carlos M. Duarte ◽  
Susana Agustí
Keyword(s):  
Red Sea ◽  
Metabolic Response ◽  
Gross Primary Production ◽  
Environmental Drivers ◽  
Community Respiration ◽  
Metabolic Rates ◽  
Nutrient Inputs ◽  
Net Community Production ◽  
Increasing Temperature ◽  
Planktonic Communities

Abstract. Resolving the environmental drivers shaping planktonic communities is fundamental for understanding their variability, in the present and the future, across the ocean. More specifically, addressing the temperature-dependence response of planktonic communities is essential as temperature plays a key role in regulating metabolic rates and thus potentially defining the ecosystem functioning. Here we quantified plankton metabolic rates along the Red Sea, a uniquely oligotrophic and warm environment, and analysed the drivers that regulate gross primary production (GPP), community respiration (CR), and net community production (NCP). The study was conducted on six oceanographic surveys following a north–south transect along the Saudi Arabian coast. Our findings revealed that GPP and CR rates increased with increasing temperature (R2=0.41 and 0.19, respectively; p<0.001 in both cases), with a higher activation energy (Ea) for GPP (1.20±0.17 eV) than for CR (0.73±0.17 eV). The higher Ea for GPP than for CR resulted in a positive relationship between NCP and temperature. This unusual relationship is likely driven by the relatively higher nutrient availability found towards the warmer region (i.e. southern Red Sea), which favours GPP rates above the threshold that separates autotrophic from heterotrophic communities (1.7 mmol O2 m−3 d−1) in this region. Due to the arid nature, the basin lacks riverine and terrestrial inputs of organic carbon to subsidise a higher metabolic response of heterotrophic communities, thus constraining CR rates. Our study suggests that GPP increases steeply with increasing temperature in the warm ocean when relatively high nutrient inputs are present.

scholarly journals Decoupling of ΔO<sub>2</sub>∕Ar and particulate organic carbon dynamics in nearshore surface ocean waters

2020 ◽  
Vol 17 (12) ◽  
pp. 3277-3298
Author(s):  
Sarah Z. Rosengard ◽  
Robert W. Izett ◽  
William J. Burt ◽  
Nina Schuback ◽  
Philippe D. Tortell
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Mixed Layer ◽  
Vertical Mixing ◽  
Optical Measurements ◽  
Community Respiration ◽  
Carbon Export ◽  
Net Community Production ◽  
High Productivity ◽  
Lower Productivity

Abstract. We report results from two Lagrangian drifter surveys off the Oregon coast, using continuous shipboard sensors to estimate mixed-layer gross primary productivity (GPP), community respiration (CR), and net community production (NCP) from variations in biological oxygen saturation (ΔO2∕Ar) and optically derived particulate organic carbon (POC). At the first drifter survey, conducted in a nearshore upwelling zone during the development of a microplankton bloom, net changes in ΔO2∕Ar and [POC] were significantly decoupled. Differences in GPP and NCP derived from ΔO2∕Ar (NCPO2/Ar) and POC (NCPPOC) time series suggest the presence of large POC losses from the mixed layer. At this site, we utilized the discrepancy between NCPO2/Ar and NCPPOC, and additional constraints derived from surface water excess nitrous oxide (N2O), to evaluate POC loss through particle export, DOC production, and vertical mixing fluxes. At the second drifter survey, conducted in lower-productivity, density-stratified offshore waters, we also observed offsets between ΔO2∕Ar and POC-derived GPP and CR rates. At this site, however, net [POC] and ΔO2∕Ar changes yielded closer agreement in NCP estimates, suggesting a tighter relationship between production and community respiration, as well as lower POC loss rates. These results provide insight into the possibilities and limitations of estimating productivity from continuous underway POC and ΔO2∕Ar data in contrasting oceanic waters. Our observations support the use of diel POC measurements to estimate NCP in lower-productivity waters with limited vertical carbon export and the potential utility of coupled O2 and optical measurements to estimate the fate of POC in high-productivity regions with significant POC export.

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.

scholarly journals Plankton Community Metabolism in Western Australia: Estuarine, Coastal and Oceanic Surface Waters

2021 ◽  
Vol 7 ◽  
Author(s):  
Lara S. Garcia-Corral ◽  
Carlos M. Duarte ◽  
Susana Agusti
Keyword(s):  
Western Australia ◽  
Gross Primary Production ◽  
Community Respiration ◽  
Thermal Dependence ◽  
Net Community Production ◽  
Oceanic Surface ◽  
Autotrophic Metabolism ◽  
Estuarine Coastal ◽  
Plankton Communities ◽  
Community Production

Net community production (NCP) is a community level process informing on the balance between production and consumption, determining the role of plankton communities in carbon and nutrient balances fueling the marine food web. An assessment of net and gross community production (NCP, GPP) and community respiration (CR) in 86 surface plankton communities sampled between 15° and 36° South along coastal Western Australia (WA) revealed a prevalence of net autotrophic metabolism (GPP/CR &gt; 1), comprising 81% of the communities sampled. NCP, GPP, and CR decreased with decreasing nutrient and chlorophyll-a concentrations, from estuarine, to coastal and oceanic waters. CR, standardized per unit chlorophyll-a, increased with temperature, with higher activation energies (Ea) than GPP per unit chlorophyll-a (Ea 1.07 ± 0.18 eV and 0.65 ± 0.15 eV, respectively) either across ecosystem types and for coastal and estuary communities alone, indicating plankton CR to increase much faster with warming than GPP. These results characterize surface plankton communities across Western Australia as CO2 sinks, the stronger thermal-dependence of respiration that gross primary production rates suggests that their role may weaken with future warming.

scholarly journals Temperature-dependence of planktonic metabolism in the Subtropical North Atlantic Ocean

2014 ◽  
Vol 11 (2) ◽  
pp. 3241-3269
Author(s):  
L. S. García-Corral ◽  
E. Barber ◽  
A. Regaudie-de-Gioux ◽  
S. Sal ◽  
J. Holding ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Temperature Dependence ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Gross Primary Production ◽  
Activation Energies ◽  
Community Respiration ◽  
Metabolic Rates ◽  
Net Community Production ◽  
Different Seasons

Abstract. The temperature dependence of planktonic metabolism in the Subtropical North Atlantic Ocean was assessed on the basis of measurements of gross primary production (GPP), community respiration (CR) and net community production (NCP), as well as experimental assessments of the response of CR to temperature manipulations. Metabolic rates were measured at 68 stations along three consecutive longitudinal transects completed during the Malaspina 2010 Expedition, in three different seasons. Temperatures gradients were observed in depth and at basin and seasonal scale. The results showed seasonal variability in the metabolic rates, being the highest rates observed during the spring transect. The overall mean integrated GPP/CR ratio was of 1.39 ± 0.27 decreasing from winter to summer and the NCP for the Subtropical North Atlantic Ocean during this cruises, was net autotrophy (NCP > 0) in about two-thirds of the total sampled communities (68.2%). Here, we reported the activation energies describing the temperature-dependence of planktonic community metabolism, which generally was higher for CR than for GPP in the Subtropical North Atlantic Ocean, as the metabolic theory of ecology predicts. Also, we performed an assessment of the activation energies describing the responses to in situ temperature at field (EaCR = 1.64 ± 0.36 eV) and those derive experimentally by temperature manipulations (EaCR = 1.45 ± 0.6 eV), which showed a great consistency.

scholarly journals Patterns in planktonic metabolism in the Mediterranean Sea

2009 ◽  
Vol 6 (4) ◽  
pp. 8569-8588
Author(s):  
A. Regaudie-de-Gioux ◽  
R. Vaquer-Sunyer ◽  
C. M. Duarte
Keyword(s):  
Mediterranean Sea ◽  
Gross Primary Production ◽  
Western Mediterranean ◽  
Community Respiration ◽  
Net Community Production ◽  
R Ratio ◽  
Heterotrophic Metabolism ◽  
The Mediterranean ◽  
Net Heterotrophy ◽  
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. GPP averaged 2.4±0.4 mmol O2m−3 d−1, CR averaged 3.8±0.5 mmol O2m−3 d−1, and NCP averaged -0.8&amp;plusmn0.6 mmol O2m−3 d−1across the studied sections, indicative of a tendency for a net heterotrophic metabolism, prevalent across studied sections of the Mediterranean Sea as reflected in 70% of negative NCP estimates. The median P/R ratio was 0.58, 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 3.5 mmol O2m−3 d−1. Although the Western Mediterranean supports a higher gross primary production than the Eastern basin does, it also supported a higher community respiration. The net heterotrophy nature of the studied sections of the Mediterranean Sea indicates that allochthonous carbon should be important to subsidise planktonic metabolism, and that the planktonic communities in the Mediterranean Sea acted as CO2 sources to the atmosphere during the study.

Sign in / Sign up

Export Citation Format

Share Document