Phytoplankton primary production, chlorophyll-a and nutrient concentrations in the water column of mountainous Lake Phewa, Nepal

Abstract. A basin-wide study was conducted in the Tana River basin (Kenya) in February 2008 (dry season), September–November 2009 (wet season) and June–July 2010 (end of the wet season) to assess the dynamics and sources of dissolved inorganic carbon (DIC) as well as to quantify CO2 fluxes, community respiration (R), and primary production (P). Samples were collected along the altitudinal gradient (from 3600 to 8 m) in several headwater streams, reservoirs (Kamburu and Masinga), and the Tana River mainstream. DIC concentrations ranged from 0.2 to 4.8 mmol L−1, with exceptionally high values (3.5 ± 1.6 mmol L−1) in Nyambene Hills tributaries. The wide range of δ13CDIC values (−15.0 to −2.4‰) indicate variable sources of DIC, with headwater streams recording more positive signatures compared to the Tana River mainstream. With with only a few exceptions, the entire riverine network was supersaturated in CO2, implying the system is a net source of CO2 to the atmosphere. pCO2 values were generally higher in the lower Tana River mainstream compared to headwater tributaries, opposite to the pattern typically observed in other river networks. This was attributed to high suspended sediment in the Tana River mainstream fuelling in-stream community respiration and net heterotrophy. This was particularly evident during the 2009 wet season campaign (median pCO2 of 1432 ppm) compared to the 2010 end of the wet season (1002 ppm) and 2008 dry season (579 ppm). First-order estimates show that in-stream community respiration was responsible for the bulk of total CO2 evasion (77 to 114%) in the Tana River mainstream, while in the tributaries, this could only account for 5 to 68% of total CO2 evasion. This suggests that CO2 evasion in the tributaries was to a substantial degree sustained by benthic mineralisation and/or lateral inputs of CO2-oversaturated groundwater. While sediment loads increased downstream and thus light availability decreased in the water column, both chlorophyll a (0.2 to 9.6 μg L−1) and primary production (0.004 to 7.38 μmol C L−1 h−1) increased consistently downstream. Diurnal fluctuations of biogeochemical processes were examined at three different sites along the river continuum (headwater, reservoir and mainstream), and were found to be substantial only in the headwater stream, moderate in the reservoir and not detectable in the Tana River mainstream. The pronounced diurnal fluctuations observed in the headwater stream were largely regulated by periphyton as deduced from the low chlorophyll a in the water column.

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Contrasting glacial meltwater effects on post-bloom phytoplankton on temporal and spatial scales in Kongsfjorden, Spitsbergen

Elem Sci Anth ◽

10.1525/elementa.307 ◽

2018 ◽

Vol 6 ◽

Cited By ~ 7

Author(s):

Willem H. van de Poll ◽

Gemma Kulk ◽

Patrick D. Rozema ◽

Corina P. D. Brussaard ◽

Ronald J. W. Visser ◽

...

Keyword(s):

Nutrient Limitation ◽

Water Column ◽

Chlorophyll A ◽

Carbon Fixation ◽

Spatial Scales ◽

Nutrient Concentrations ◽

Fixation Rate ◽

Glacial Meltwater ◽

Chl A ◽

N Limitation

Glacial meltwater discharge in fjords on the west coast of Spitsbergen is increasing due to climate change. The influence of this discharge on phytoplankton nutrient limitation, composition, productivity and photophysiology was investigated in central (M) and inner (G) Kongsfjorden (79°N, 11°40’E). Freshwater influx intensified stratification during June 2015, coinciding with surface nutrient depletion. Surface nutrient concentrations were negatively correlated with stratification strength at station M. Here, nitrate addition assays revealed increasing N limitation of surface phytoplankton during the second half of June, which was followed by a pronounced compositional change within the flagellate-dominated phytoplankton community as dictyochophytes (85% of chl a) were replaced with smaller haptophytes (up to 60% of chlorophyll a) and prasinophytes (20% of chlorophyll a). These changes were less pronounced at station G, where surface phosphate, ammonium and nitrate concentrations were occasionally higher, and correlated with wind direction, suggesting wind-mediated transport of nutrient-enriched waters to this inner location. Therefore, glacial meltwater discharge mediated nutrient enrichment in the inner fjord, and enhanced stratification in inner and central Kongsfjorden. Surface chlorophyll a and water column productivity showed 3–4-fold variability, and did not correlate with nutrient limitation, euphotic zone depth, or changed taxonomic composition. However, the maximum carbon fixation rate and photosynthetic efficiency showed weak positive correlations to prasinophyte, cryptophyte, and haptophyte chlorophyll a. The present study documented relationships between stratification, N limitation, and changed phytoplankton composition, but surface chlorophyll a concentration, phytoplankton photosynthetic characteristics, and water column productivity in Kongsfjorden appeared to be driven by mechanisms other than N limitation.

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Importance of Latitude and Organic Color on Phytoplankton Primary Productivity in Florida Lakes

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f91-138 ◽

1991 ◽

Vol 48 (7) ◽

pp. 1145-1150 ◽

Cited By ~ 11

Author(s):

John R. Beaver ◽

Thomas L. Crisman

Keyword(s):

Primary Production ◽

Chlorophyll A ◽

Primary Productivity ◽

Phytoplankton Biomass ◽

Nutrient Concentrations ◽

Empirical Equations ◽

Strongly Correlated ◽

Florida Lakes ◽

Vegetative Season

A characterization of primary productivity patterns in subtropical Florida lakes along increasing gradients of both dissolved organic color and phytoplankton biomass is presented. Volumetric expression of gross primary productivity was more strongly correlated with chlorophyll a and nutrient concentrations than was areal expression. Primary production in clearwater (<75 Pt units) lakes was more predictable than colored (>75 Pt units) lakes. Areal production in Florida lakes was intermediate to the tropical and temperate regions, although volumetric productivity during the vegetative season (May–September) was not significantly different from temperate zone lakes for the same period. Predictive abilities of empirical equations describing primary productivity in Florida lakes are improved by distinguishing colored and clear lakes.

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Seasonal variability and annual Laptev sea phytoplankton primary production using MODIS-aqua data

Исследования Земли из космоса ◽

10.31857/s0205-96142019648-65 ◽

2019 ◽

pp. 48-65

Author(s):

A. B. Demidov ◽

S. V. Sheberstov ◽

V. I. Gagarin

Keyword(s):

Primary Production ◽

Water Column ◽

Seasonal Variability ◽

Sea Water ◽

Laptev Sea ◽

Phytoplankton Primary Production ◽

Production Values ◽

Northwestern Region ◽

Maximum Water ◽

Southeastern Region

Studies of seasonal variability of Laptev Sea water column primary production and evaluation of its annual values were performed using MODIS-Aqua data (20022018). To reach that result regional-specific primary production and chlorophyll algorithms were used for the first time. Based on multiyear averaged daily primary production Northwestern and Southeastern regions were distinguished in the Laptev Sea. Seasonal variations in water column primary production in the Northwestern region were characterized by the maximum in June (245 mgC m‑2 d‑1). In the Southeastern region and for all Laptev Sea the maximum water column primary production values were denoted from May to July, 273282 mgC m‑2 d‑1 and 256281 mgC m‑2 d‑1, respectively. Daily primary production and annual values of total primary production in the Southeastern region were, respectively, 1.9 and 3 fold higher than in the Northwestern region. Multiyear averaged value of Laptev Sea water column primary production was equal to 125 mgC m‑2 d‑1 and total annual primary production was equal to 8 1012 gC.

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Influence of anthropogenic nutrient inputs on rates of coastal ocean nitrogen and carbon cycling in the Southern California Bight, United States

Elem Sci Anth ◽

10.1525/elementa.2020.00145 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Karen McLaughlin ◽

Meredith D. A. Howard ◽

George Robertson ◽

Carly D. A. Beck ◽

Minna Ho ◽

...

Keyword(s):

Primary Production ◽

Chlorophyll A ◽

Southern California ◽

Regional Scale ◽

Nitrogen Loading ◽

Southern California Bight ◽

Treated Wastewater ◽

Nutrient Concentrations ◽

Reference Area ◽

Nutrient Inputs

Coastal nitrogen enrichment is a global environmental problem that can influence acidification, deoxygenation, and subsequent habitat loss in ways that can be synergistic with global climate change impacts. In the Southern California Bight, an eastern boundary upwelling system, modeling of wastewater discharged through ocean outfalls has shown that it effectively doubles nitrogen loading to urban coastal waters. However, effects of wastewater outfalls on rates of primary production and respiration, key processes through which coastal acidification and deoxygenation are manifested, have not been directly linked to observed trends in ambient chlorophyll a, oxygen, or pH. Here, we follow a “reference-area” approach and compare nutrient concentrations and rates of nitrification, primary production, and respiration observed in areas within treated wastewater effluent plumes to areas spatially distant from ocean outfalls where we expected minimal plume influence. We document that wastewater nutrient inputs had an immediate, local effect on nutrient stoichiometry, elevating ammonium and nitrite concentrations by 4 µM and 0.2 µM (on average), respectively, and increasing dissolved nitrogen-to-phosphorus ratios 7-fold within the plume. Chlorophyll a increased slightly by 1 µg L–1 in the upper 60 m of the water column (on average), and δ13C and δ15 N of suspended particulate matter, an integrated measure of primary production, increased by 1.3% and 1%, respectively (on average). Nitrification rates within the plume increased by 17 nmol L–1 day–1 (on average). We did not observe a significant near-plume effect on δ18O and δ15 N of dissolved nitrate + nitrite, an indicator of nitrogen assimilation into biomass, on rates of primary production and respiration or on dissolved oxygen concentration, suggesting that any potential impact from wastewater on these key features is moderated by other factors, notably water mass mixing. These results indicate that a “reference-area” approach may be insufficient to document regional-scale impacts of nutrients.

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Satellite estimation of chlorophyll-a concentration and phytoplankton primary production in the Sea of Azov

Doklady Biological Sciences ◽

10.1134/s0012496610030142 ◽

2010 ◽

Vol 432 (1) ◽

pp. 216-219 ◽

Cited By ~ 4

Author(s):

G. G. Matishov ◽

V. V. Povazhnyi ◽

S. V. Berdnikov ◽

W. J. Moses ◽

A. A. Gitelson

Keyword(s):

Primary Production ◽

Chlorophyll A ◽

Sea Of Azov ◽

Phytoplankton Primary Production ◽

Chlorophyll A Concentration ◽

The Sea Of Azov

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Productivitatea fitoplanctonului fluviului Nistru și lacului de acumulare Dubăsari în condițiile impactului factorilor naturali și antropici

10.53937/9789975151979.08 ◽

2021 ◽

Author(s):

Laurentia Ungureanu ◽

◽

Daria Tumanova ◽

Grigore Ungureanu ◽

◽

...

Keyword(s):

Primary Production ◽

Vegetation Period ◽

Nutrient Concentrations ◽

Organic Substances ◽

Phytoplankton Primary Production ◽

Structure Changes ◽

R Ratio ◽

Production Values ◽

Spatial Fluctuations ◽

Negative Balance

The article presents the results on the study of productivity of phytoplankton and destruction of organic matter in the Dniester River and Dubasari reservoir in 2020. The values of primary production in Dniester River varied during the vegetation period within the limits of 0.81-3.79 gO2/m-2 24h, and of the destruction of organic substances between 3.9-45.12 gO2/m-2 24h. In the Dubasari reservoir, the primary production of phytoplankton was significantly influenced by the hydrochemical and hydrobiological state of the waters from the middle sector of the Dniester River and varied within 0.572.82 gO2/m-2 24h. The values of destruction of organic substances exceeded the values of primary production and registering values between 2.1623.66 gO2/m-2 24h. The seasonal and spatial fluctuations of phytoplankton primary production values in Dniester river and Dubasari reservoir are followed by successions of phytoplankton structure, changes in nutrient concentrations and oscillations of water transparency values. The values of destruction of organic substances were higher than primary production values. The A/R ratio reflect a negative balance of formation of organic substances in Dniester River and Dubasari reservoir.

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Dynamics of dissolved inorganic carbon and aquatic metabolism in the Tana River Basin, Kenya

Biogeosciences Discussions ◽

10.5194/bgd-10-5175-2013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 5175-5221 ◽

Cited By ~ 3

Author(s):

F. Tamooh ◽

A. V. Borges ◽

F. J. R. Meysman ◽

K. Van Den Meersche ◽

F. Dehairs ◽

...

Keyword(s):

Primary Production ◽

Water Column ◽

Chlorophyll A ◽

Inorganic Carbon ◽

Dissolved Inorganic Carbon ◽

Community Respiration ◽

Wet Season ◽

Stream Community ◽

Tana River ◽

Diurnal Fluctuations

Abstract. A basin-wide study was conducted in the Tana River Basin (Kenya), in February 2008 (dry season), September–November 2009 (wet season), and June–July 2010 (end of the wet season) to assess the dynamics and sources of dissolved inorganic carbon (DIC) as well as to quantify CO2 fluxes, community respiration (R), and primary production (P). Samples were collected along the altitudinal gradient (from 3600 m to 8 m) in several headwater streams, reservoirs (Kamburu and Masinga), and main Tana River. DIC concentrations ranged from 0.2 mmol L–1 to 4.8 mmol L–1 but with exceptionally high values (3.5 ± 1.6 mmol L–1) in Nyambene Hills tributaries. The wide range of δ13CDIC values (−15.0‰ to −2.4‰) indicate variable sources of DIC with headwater streams recording higher signatures compared to main Tana River. With few exceptions, the entire riverine network was supersaturated in CO2, implying the system is a net source of CO2 to the atmosphere. pCO2 values were generally higher in the lower main Tana River compared to headwater tributaries, opposite to the pattern typically observed in other river networks. This was attributed to high suspended sediment in the main Tana River fuelling in-stream community respiration and net heterotrophy. This was particularly evident during 2009 wet season campaign (median pCO2 of 1432 ppm) compared to 2010 end of wet season (1002 ppm) and 2008 dry season (579 ppm). First-order estimates show in-stream community respiration was responsible for the bulk of total CO2 evasion (59% to 89%) in main Tana River while in tributaries respiration accounted for 4% to 52% of total CO2 evasion, suggesting CO2evasion in tributaries was sustained by processes than respiration, such as CO2-oversaturated groundwater input. While sediment loads increase downstream and thus light availability decreases in the water column, both chlorophyll a (0.2 μg L–1 to 9.6 μg L–1) and primary production (0.004 μmol L–1 h–1 to 7.38 μmol L–1 h–1) increased consistently downstream. Diurnal fluctuations of biogeochemical processes were examined at three different sites along the river continuum (headwater, reservoir, and mainstream), and were found to be substantial only in the headwater stream, moderate in the reservoir and not detectable at main Tana River. The pronounced diurnal fluctuations observed in the headwater stream were largely regulated by periphyton as deduced from the low chlorophyll a in the water column.

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Spatial and Temporal Dynamics of Phytoplankton Primary Production in the Teterev River

Hydrobiological Journal ◽

10.1615/hydrobj.v44.i1.10 ◽

2008 ◽

Vol 44 (1) ◽

pp. 3-15

Author(s):

V. I. Shcherbak ◽

Yu. S. Kuzminchuk

Keyword(s):

Primary Production ◽

Temporal Dynamics ◽

Phytoplankton Primary Production ◽

Spatial And Temporal Dynamics

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