scholarly journals Rates of primary production in groundwater rival those in oligotrophic marine systems

2021 ◽  
Author(s):  
Will A Overholt ◽  
Susan Trumbore ◽  
Xiaomei Xu ◽  
Till L V Bornemann ◽  
Alexander J Probst ◽  
...  
Keyword(s):  
Primary Production ◽  
Surface Waters ◽  
Carbon Fixation ◽  
Euphotic Zone ◽  
Rate Data ◽  
Carbonate Aquifer ◽  
Marine Systems ◽  
Marine Surface ◽  
Terrestrial Subsurface

The terrestrial subsurface contains nearly all of Earth's freshwater reserves and harbors upwards of 60% of our planet's total prokaryotic biomass. While genetic surveys suggest these organisms rely on in situ carbon fixation, rather than the translocation of photosynthetically derived organic carbon, corroborating measurements of carbon fixation in the subsurface are absent. Using a novel ultra-low level 14C-labeling technique, we show that in situ carbon fixation rates in a carbonate aquifer reached 10% of the median rates measured in oligotrophic marine surface waters, and were up to six-fold greater than those observed in lower euphotic zone waters where deep chlorophyll levels peak. Empirical carbon fixation rates were substantiated by both nitrification and anammox rate data. Metagenomic analyses revealed a remarkable abundance of putative chemolithoautotrophic members of an uncharacterized order of Nitrospiria - the first representatives of this class expected to fix carbon via the Wood-Ljungdahl pathway. Based on these fixation rates, we extrapolate global primary production in carbonate groundwaters to be 0.11 Pg of carbon per year.

scholarly journals Comparison of Primary Production Using in situ and Satellite-Derived Values at the SEATS Station in the South China Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Yung-Yen Shih ◽  
Fuh-Kwo Shiah ◽  
Chao-Chen Lai ◽  
Wen-Chen Chou ◽  
Jen-Hua Tai ◽  
...  
Keyword(s):  
Primary Production ◽  
Carbon Fixation ◽  
Negative Relationship ◽  
Euphotic Zone ◽  
Production Model ◽  
Global Ocean ◽  
The South ◽  
Fixation Rate ◽  
Zone Depth

Satellite-based observations of primary production (PP) are broadly used to assess carbon fixation rate of phytoplankton in the global ocean with small spatiotemporal limitations. However, the remote sensing can only reach the ocean surface, the assumption of a PP vertically exponential decrease with increasing depth from the surface to the bottom of euphotic zone may cause a substantial and potential discrepancy between in situ measurements and satellite-based observations of PP. This study compared euphotic zone integrated PP derived from measurements based on ship-based in situ incubation (i.e., PPin situ) and those derived from the satellite-based vertically generalized production model (VGPM; PPVGPM) for the period 2003∼2016 at the South East Asian Time-series Study (SEATS) station. PP values obtained during the NE-monsoon (NEM: Nov∼Mar; PPin situ = 323 ± 134; PPVGPM = 443 ± 142 mg-C m–2 d–1) were ∼2-fold higher than those recorded during the SW-monsoon (SWM: Apr∼Oct; PPin situ = 159 ± 58; PPVGPM = 250 ± 36 mg-C m–2 d–1), regardless of the method used for derivation. The main reason for the higher PP values during the NEM appears to have been a greater abundance of inorganic nutrients were made available by vertical advection. Note that on average, PPin situ estimates were ∼50% lower than PPVGPM estimates, regardless of the monsoon. These discrepancies can be mainly attributed to differences from the euphotic zone depth between satellite-based and in situ measurements. The significantly negative relationship between PP measurements obtained in situ and sea surface temperatures observed throughout this study demonstrates that both methods are effective indicators in estimating PP. Overall, our PPin situ analysis indicates that a warming climate is unfavorable for primary production in low-latitude open ocean ecosystems.

Zinc marine biogeochemistry in seawater: a review

2012 ◽  
Vol 63 (7) ◽  
pp. 644 ◽  
Author(s):  
Marie Sinoir ◽  
Edward C. V. Butler ◽  
Andrew R. Bowie ◽  
Mathieu Mongin ◽  
Pavel N. Nesterenko ◽  
...  
Keyword(s):  
Surface Waters ◽  
Phytoplankton Community ◽  
Conceptual Models ◽  
Biogeochemical Cycles ◽  
Phytoplankton Growth ◽  
Laboratory Studies ◽  
Marine Systems ◽  
Subtle Effect ◽  
Marine Biogeochemistry ◽  
Marine Surface

The interest in trace element biogeochemistry has arisen from the well demonstrated iron hypothesis that revealed the central role that iron exerts on oceanic primary and associated biogeochemical cycles. The essentiality of zinc for key biological enzymes, coupled with a nutrient-like vertical distribution with low dissolved concentrations in many marine surface waters, provided motivation to study zinc in marine systems. Laboratory studies have confirmed the importance of zinc to sustain phytoplankton growth and its influence on the composition of the phytoplankton community. However, mixed results were obtained in the field, which suggest a more subtle effect of zinc on oceanic phytoplankton growth than iron. As a consequence, consensus on its biological role, mechanisms at play or regional versus global relevance is currently lacking and highlights the need for new conceptual models of zinc in marine systems. The recent GEOTRACES program is generating new data approaches to discuss and understand further zinc behaviour in the ocean.

scholarly journals Spatio-Temporal Variability of Phytoplankton Primary Production in Baltic Lakes Using Sentinel-3 OLCI Data

2020 ◽  
Vol 12 (15) ◽  
pp. 2415
Author(s):  
Tuuli Soomets ◽  
Kristi Uudeberg ◽  
Kersti Kangro ◽  
Dainis Jakovels ◽  
Agris Brauns ◽  
...  
Keyword(s):  
Primary Production ◽  
Temporal Variability ◽  
Carbon Fixation ◽  
Remote Sensing Data ◽  
Spatial And Temporal Variation ◽  
Spatial And Temporal Variability ◽  
Phytoplankton Primary Production ◽  
Spatio Temporal ◽  
Lake Size

Phytoplankton primary production (PP) in lakes play an important role in the global carbon cycle. However, monitoring the PP in lakes with traditional complicated and costly in situ sampling methods are impossible due to the large number of lakes worldwide (estimated to be 117 million lakes). In this study, bio-optical modelling and remote sensing data (Sentinel-3 Ocean and Land Colour Instrument) was combined to investigate the spatial and temporal variation of PP in four Baltic lakes during 2018. The model used has three input parameters: concentration of chlorophyll-a, the diffuse attenuation coefficient, and incident downwelling irradiance. The largest of our studied lakes, Võrtsjärv (270 km2), had the highest total yearly estimated production (61 Gg C y−1) compared to the smaller lakes Lubans (18 Gg C y−1) and Razna (7 Gg C y−1). However, the most productive was the smallest studied, Lake Burtnieks (40.2 km2); although the total yearly production was 13 Gg C y−1, the daily average areal production was 910 mg C m−2 d−1 in 2018. Even if lake size plays a significant role in the total PP of the lake, the abundance of small and medium-sized lakes would sum up to a significant contribution of carbon fixation. Our method is applicable to larger regions to monitor the spatial and temporal variability of lake PP.

scholarly journals Incorporation of Glucose under Anoxic Conditions by Bacterioplankton from Coastal North Sea Surface Waters

2005 ◽  
Vol 71 (4) ◽  
pp. 1709-1716 ◽  
Author(s):  
Cecilia Alonso ◽  
Jakob Pernthaler
Keyword(s):  
North Sea ◽  
Surface Waters ◽  
Anaerobic Metabolism ◽  
Strictly Aerobic ◽  
Phylogenetic Groups ◽  
Anoxic Conditions ◽  
Membrane Filters ◽  
Coastal Marine ◽  
Marine Surface

ABSTRACT It has been hypothesized that the potential for anaerobic metabolism might be a common feature of bacteria in coastal marine waters (L. Riemann and F. Azam, Appl. Environ. Microbiol. 68: 5554-5562, 2002). Therefore, we investigated whether different phylogenetic groups of heterotrophic picoplankton from the coastal North Sea were able to take up a simple carbon source under anoxic conditions. Oxic and anoxic incubations (4 h) or enrichments (24 h) of seawater with radiolabeled glucose were performed in July and August 2003. Bacteria with incorporated substrate were identified by using a novel protocol in which we combined fluorescence in situ hybridization and microautoradiography of cells on membrane filters. Incorporation of glucose under oxic and anoxic conditions was found in α-Proteobacteria, γ-Proteobacteria, and the Cytophaga-Flavobacterium cluster of the Bacteroidetes at both times, but not in marine Euryarchaeota. In July, the majority of cells belonging to the α-proteobacterial Roseobacter clade showed tracer incorporation both in oxic incubations and in oxic and anoxic enrichments. In August, only a minority of the Roseobacter cells, but most bacteria affiliated with Vibrio spp., were able to incorporate the tracer under either condition. A preference for glucose uptake under anoxic conditions was observed for bacteria related to Alteromonas and the Pseudoalteromonas-Colwellia group. These genera are commonly considered to be strictly aerobic, but facultatively fermentative strains have been described. Our findings suggest that the ability to incorporate substrates anaerobically is widespread in pelagic marine bacteria belonging to different phylogenetic groups. Such bacteria may be abundant in fully aerated coastal marine surface waters.

Seasonal phytoplankton production in the western English Channel 1964–1974

1978 ◽  
Vol 58 (4) ◽  
pp. 943-953 ◽  
Author(s):  
G. T. Boalch ◽  
D. S. Harbour ◽  
E. I. Butler
Keyword(s):  
Primary Production ◽  
Carbon Fixation ◽  
Statistical Analyses ◽  
Annual Production ◽  
Phytoplankton Production ◽  
English Channel ◽  
Cell Counts

Over a period of 10 years, 1964–74, primary production has been measured at three stations across the western English Channel using the 14C method. Results for carbon fixation, cell counts and mean seasonal production are illustrated. Statistical analyses show that, at two of the three stations, carbon fixation in 1966 was significantly greater than expected and that annual production differs significantly at each of the stations. The variations observed are discussed in relation to other changes recorded in the area during the same period. A deck incubator used for simulated in situ14C experiments is illustrated.

scholarly journals Primary production in the Chukchi Sea with potential effects of freshwater content

2016 ◽  
Vol 13 (3) ◽  
pp. 737-749 ◽  
Author(s):  
M. S. Yun ◽  
T. E. Whitledge ◽  
D. Stockwell ◽  
S. H. Son ◽  
J. H. Lee ◽  
...  
Keyword(s):  
Primary Production ◽  
Chukchi Sea ◽  
Euphotic Zone ◽  
Northern Region ◽  
Current Status ◽  
Production Rates ◽  
Significant Relationships ◽  
Using Data ◽  
Seasonal And Interannual Variations

Abstract. The in situ primary production rates and various environmental variables were investigated in the Chukchi Sea during the RUSALCA expedition, which was conducted in 2012, to identify the current status of primary production. A 13C–15N dual-tracer technique was used to measure the daily primary production rates, which ranged from 0.02 to 1.61 g C m−2 d−1 (mean ±SD  =  0.42 ± 0.52 g C m−2 d−1). The primary production rates showed large regional differences, with the southern region (0.66 ± 0.62 g C m−2 d−1) producing approximately 5 times as much as the northern region (0.14 ± 0.10 g C m−2 d−1), which was primarily due to the differences in phytoplankton biomasses induced by regional nutrient conditions. The primary production rates in the Chukchi Sea were averaged using data acquired during the three different RUSALCA expeditions (2004, 2009, and 2012) as 0.33 g C m−2 d−1 (SD  =  0.40 g C m−2 d−1), which was significantly lower than previously reported rates. In addition to strong seasonal and interannual variations in primary production, recent decreases in the concentrations of major inorganic nutrients and chlorophyll a could be among the reasons for the recent low primary production in the Chukchi Sea because the primary production is mainly affected by nutrient concentration and phytoplankton biomass. The nutrient inventory and primary production appear to be largely influenced by the freshwater content (FWC) variability in the region due to the significant relationships between FWC, nitrate inventory (r  =  0.54, p < 0.05), and primary production rates (r  =  0.56, p < 0.05). Moreover, we found highly significant relationships between the nutrient inventory and the primary production rates (r  =  0.75, p < 0.001). In conclusion, the primary production in the Chukchi Sea is primarily controlled by nutrient availability, which is strongly related to the FWC variability. Our results imply that the predicted increase in freshwater accumulation might cause a decrease in primary production by lowering the nutrient inventory in the euphotic zone of the Chukchi Sea.

scholarly journals Saharan dust nutrients promote Vibrio bloom formation in marine surface waters

2016 ◽  
Vol 113 (21) ◽  
pp. 5964-5969 ◽  
Author(s):  
Jason R. Westrich ◽  
Alina M. Ebling ◽  
William M. Landing ◽  
Jessica L. Joyner ◽  
Keri M. Kemp ◽  
...  
Keyword(s):  
Microbial Community ◽  
Surface Waters ◽  
Fold Increase ◽  
Field Studies ◽  
Marine Ecology ◽  
Saharan Dust ◽  
Bloom Formation ◽  
Marine Surface ◽  
Nutrient Influx

Vibrio is a ubiquitous genus of marine bacteria, typically comprising a small fraction of the total microbial community in surface waters, but capable of becoming a dominant taxon in response to poorly characterized factors. Iron (Fe), often restricted by limited bioavailability and low external supply, is an essential micronutrient that can limit Vibrio growth. Vibrio species have robust metabolic capabilities and an array of Fe-acquisition mechanisms, and are able to respond rapidly to nutrient influx, yet Vibrio response to environmental pulses of Fe remains uncharacterized. Here we examined the population growth of Vibrio after natural and simulated pulses of atmospherically transported Saharan dust, an important and episodic source of Fe to tropical marine waters. As a model for opportunistic bacterial heterotrophs, we demonstrated that Vibrio proliferate in response to a broad range of dust-Fe additions at rapid timescales. Within 24 h of exposure, strains of Vibrio cholerae and Vibrio alginolyticus were able to directly use Saharan dust–Fe to support rapid growth. These findings were also confirmed with in situ field studies; arrival of Saharan dust in the Caribbean and subtropical Atlantic coincided with high levels of dissolved Fe, followed by up to a 30-fold increase of culturable Vibrio over background levels within 24 h. The relative abundance of Vibrio increased from ∼1 to ∼20% of the total microbial community. This study, to our knowledge, is the first to describe Vibrio response to Saharan dust nutrients, having implications at the intersection of marine ecology, Fe biogeochemistry, and both human and environmental health.

scholarly journals Dependence of the Photosynthesis Quantum Yield on Phytoplankton Light Absorption: Equations for Assessing Primary Production in the Black Sea

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
T. Ya. Churilova ◽  
V. V. Suslin ◽  
H. M. Sosik ◽  
◽  
◽  
...  
Keyword(s):  
Quantum Yield ◽  
Primary Production ◽  
Black Sea ◽  
Light Absorption ◽  
Euphotic Zone ◽  
The Black Sea ◽  
Absorption Coefficients ◽  
Phytoplankton Pigments ◽  
Downwelling Irradiance

Purpose. Based on the results of the investigations that were performed during the scientific cruise and included the water hydrophysical characteristics, the chlorophyll a concentration, the photosynthesis-light dependences, the spectral light absorption coefficients by phytoplankton, and the spectral quantum downwelling irradiance, the dependence of the photosynthesis quantum yield upon the environmental factors was studied with the purpose of adaptation of the developed for the Baltic Sea approach for assessing the photosynthesis quantum yield, to the Black Sea. Methods and Results. Complex hydrophysical and biological studies were carried out at several depths within the photosynthesis zone. Spectral bio-optical parameters were measured in accordance with the modern NASA protocol (2018). The experiments on studying the photosynthesis-light relationship were performed under the temperature and light conditions close to the in situ ones. The quantum yield of photosynthesis was calculated based on the parameters of photosynthesis-light dependences (photosynthesis efficiency, light saturation parameter) and the spectral light absorption coefficients by phytoplankton pigments. It was found out that the main photosynthetic characteristics of phytoplankton including the photosynthesis maximum quantum yield and the portion of photoprotective accessory pigments in the total light absorption by phytoplankton varied with depth within the euphotic zone due to phytoplankton adaptation to the environment factors during the period of water seasonal stratification. The relationship between the photosynthesis quantum yield and the number of solar energy quanta absorbed by the photosynthetically active phytoplankton pigments was revealed. The results of the performed research allowed for modifying the equation for calculating the quantum yield for the Black Sea environment conditions according to the approach developed for the other water areas. Conclusions. For the first time, comprehensive studies carried out in the Black Sea and including the measurements of the photosynthesis-light dependences, the spectral light absorption coefficients by phytoplankton and spectral downwelling irradiance at particular optical depths within the euphotic zone enabled to reveal the equation for calculating the photosynthesis quantum yield, which could be applied for calculating primary production of the Black Sea using the spectral approach based both on the results of in situ measurements and the remote sensing data.

scholarly journals The potential effects of fresh water content on the primary production in the Chukchi Sea

2015 ◽  
Vol 12 (16) ◽  
pp. 13511-13544
Author(s):  
M. S. Yun ◽  
T. E. Whitledge ◽  
D. Stockwell ◽  
J. H. Lee ◽  
J. W. Park ◽  
...  
Keyword(s):  
Primary Production ◽  
Chukchi Sea ◽  
Euphotic Zone ◽  
Northern Region ◽  
Current Status ◽  
Production Rates ◽  
Significant Relationships ◽  
Using Data ◽  
Seasonal And Interannual Variations

Abstract. The in situ primary production rates and various environmental variables were investigated in the Chukchi Sea during the 3rd RUSALCA expedition, which was conducted in 2012, to identify the current status of primary production. A 13C-15N dual tracer technique was used to measure the daily primary production rates, which ranged from 0.02 to 1.61 g C m−2 d−1 (mean ± SD = 0.42 ± 0.52 g C m−2 d−1). The primary production rates showed large regional differences, with the southern region (0.66 ± 0.62 g C m−2 d−1) producing approximately five times as much as the northern region (0.14 ± 0.10 g C m−2 d−1), which was primarily due to the differences in phytoplankton biomasses induced by regional nutrient conditions. The primary production rates in the Chukchi Sea were averaged using data acquired during the three different RUSALCA expeditions (2004, 2009, and 2012) as 0.33 g C m−2 d−1 (SD = 0.40 g C m−2 d−1), which was significantly lower than previously reported rates. In addition to strong seasonal and interannual variations in primary production, recent decreases in the concentrations of major inorganic nutrients and chlorophyll a could be among the reasons for the recent low primary production in the Chukchi Sea because the primary production is mainly affected by nutrient concentration and phytoplankton biomass. The nutrient inventory and primary production appear to be largely influenced by the freshwater content (FWC) variability in the region due to the significant relationships between FWC, nitrate concentrations (r = 0.54, p < 0.05) and primary production rates (r = 0.56, p < 0.05). Moreover, we found highly significant relationships between the nutrient levels and the primary production rates (r = 0.75, p < 0.001). In conclusion, the primary production in the Chukchi Sea is primarily controlled by nutrient availability which is strongly related to the FWC variability. Our results imply that the predicted increase in freshwater accumulation might cause a decrease in primary production by lowering the nutrient inventory in the euphotic zone of the Chukchi Sea.

The Utility of Light-Saturation Models for Estimating Marine Primary Productivity in the Field: A Comparison with Conventional "Simulated" In Situ Methods

1985 ◽  
Vol 42 (5) ◽  
pp. 864-872 ◽  
Author(s):  
W. G. Harrison ◽  
T. Platt ◽  
M. R. Lewis
Keyword(s):  
Surface Waters ◽  
Euphotic Zone ◽  
Light Level ◽  
Light Sources ◽  
Production Rates ◽  
Average Model ◽  
Direct Measurements ◽  
In Situ Methods ◽  
Marine Primary Productivity

Primary production rates derived from model photosynthesis–light (P–l) curves and daily solar radiation data were compared with direct measurements using "simulated" in situ incubations in arctic and temperate marine waters. On the average, model estimates were slightly higher in surface waters and significantly lower at the bottom of the euphotic zone (1% light level) than were the measured values. This could be partially explained by spectral differences in incubation light sources. However, areal production rates were statistically indistinguishable. Use of P-l models without a photoinhibition term and incorporating P-l pararmeters from mixed-layer populations gave the best overall agreement with directly measured production rates.

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