Nearshore–offshore comparison of chlorophyll a and phytoplankton production in the dreissenid-colonized eastern basin of Lake Erie

2006 ◽  
Vol 63 (5) ◽  
pp. 1115-1129 ◽  
Author(s):  
David C Depew ◽  
Stephanie J Guildford ◽  
Ralph E.H Smith
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Lake Erie ◽  
Light Attenuation ◽  
Phytoplankton Production ◽  
Light Climate ◽  
Production Rates ◽  
Chl A ◽  
Underwater Light Climate

Planktonic primary production, chlorophyll a (chl a), underwater light climate, and total phosphorus were measured at 18 stations during 2001 and 2002 in eastern Lake Erie to characterize spatial and seasonal patterns in this system colonized by dreissenid mussels (Dreissena spp.). Areal production rates and chl a displayed a seasonal pattern typical of the Laurentian Great Lakes, with highest production in the early and late summer. Daily and seasonal (May–October) primary production was significantly lower nearshore than offshore. Although light attenuation was similar between nearshore and offshore, the nearshore light climate was generally more favorable for phytoplankton because of shallower mixing depths. However, chl a was significantly lower nearshore, which accounted for most of the depression in production rates. Nearshore chl a was lower than predicted from relationships with total phosphorus in comparable dreissenid-free systems. Offshore, subepilimnetic communities contributed up to 67% of daily production but only up to 19% of seasonal production. The depression of chl a and primary production in the nearshore was a reversal from historic patterns in eastern Lake Erie and from the pattern traditionally expected in large lakes. Decreased external nutrient loading and dreissenid colonization may both have contributed to this new spatial pattern, but dreissenids appear to be key agents.

Relationships of Phytoplankton Biomass with Soluble Nutrients, Primary Production, and Chlorophyll a in Lake Erie, 1970

1976 ◽  
Vol 33 (3) ◽  
pp. 601-611 ◽  
Author(s):  
M. Munawar ◽  
N. M. Burns
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Lake Erie ◽  
Soluble Reactive Phosphorus ◽  
Distribution Patterns ◽  
Statistical Procedure ◽  
Annual Average ◽  
Average Distribution ◽  
Reactive Phosphorus

Comparison of the annual average distribution patterns of phytoplankton biomass, chlorophyll a, primary production, soluble reactive phosphorus, nitrate + nitrite, and ammonia concentrations revealed that these six variables had very similar distributions in Lake Erie during 1970. However, statistical analysis of the data only revealed a few consistent relationships between these variables. The phytoplankton biomass was correlated with chlorophyll a only in the summer and fall as was primary production with chlorophyll a and biomass. There was no correlation between these three variables during the spring. Also, there was no consistent relationship between biomass and soluble nutrients. The primary production and activity coefficient (mg Cassimilated per milligram phytoplankton biomass per day) were found to be unrelated to temperature. The statistical procedure of factor analysis showed that in the spring, primary production correlated with the phosphorus and nitrogen soluble nutrients only, whereas during summer, primary production correlated with biomass, chlorophyll a, the major plankton groups (Cyanophyta, Chlorophyta, Chrysomonadinae, and Diatomeae), and the phosphorus nutrients. In the fall, production was positively correlated with phytoplankton biomass and with the Chlorophyta in particular. The use of chlorophyll a and temperature as variables in the equation to estimate phytoplankton growth in Lake Erie was found to be questionable.

scholarly journals Spatiotemporal variability of light attenuation and net ecosystem metabolism in a back-barrier estuary

Ocean Science ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 593-614
Author(s):  
Neil K. Ganju ◽  
Jeremy M. Testa ◽  
Steven E. Suttles ◽  
Alfredo L. Aretxabaleta
Keyword(s):  
Dissolved Oxygen ◽  
Primary Production ◽  
Chlorophyll A ◽  
Light Attenuation ◽  
Sediment Resuspension ◽  
Ecosystem Metabolism ◽  
Spatiotemporal Variability ◽  
Net Ecosystem Metabolism ◽  
Spatial Homogeneity

Abstract. Quantifying system-wide biogeochemical dynamics and ecosystem metabolism in estuaries is often attempted using a long-term continuous record at a single site or short-term records at multiple sites due to sampling limitations that preclude long-term monitoring. However, differences in the dominant primary producer at a given location (e.g., phytoplankton versus benthic producers) control diel variations in dissolved oxygen and associated ecosystem metabolism, and they may confound metabolic estimates that do not account for this variability. We hypothesize that even in shallow, well-mixed estuaries there is strong spatiotemporal variability in ecosystem metabolism due to benthic and water-column properties, as well as ensuing feedbacks to sediment resuspension, light attenuation, and primary production. We tested this hypothesis by measuring hydrodynamic properties, biogeochemical variables (fluorescent dissolved organic matter – fDOM, turbidity, chlorophyll a fluorescence, dissolved oxygen), and photosynthetically active radiation (PAR) over 1 year at 15 min intervals at paired channel (unvegetated) and shoal (vegetated by eelgrass) sites in Chincoteague Bay, Maryland–Virginia, USA, a shallow back-barrier estuary. Light attenuation (KdPAR) at all sites was dominated by turbidity from suspended sediment, with lower contributions from fDOM and chlorophyll a. However, there was significant seasonal variability in the resuspension–shear stress relationship on the vegetated shoals, but not in adjacent unvegetated channels. This indicated that KdPAR on the shoals was mediated by submerged aquatic vegetation (SAV) and possibly microphytobenthos presence in the summer, which reduced resuspension and therefore KdPAR. We also found that gross primary production (Pg) and KdPAR were significantly negatively correlated on the shoals and uncorrelated in the channels, indicating that Pg over the vegetated shoals is controlled by a feedback loop between benthic stabilization by SAV and/or microphytobenthos, sediment resuspension, and light availability. Metabolic estimates indicated substantial differences in net ecosystem metabolism between vegetated and unvegetated sites, with the former tending towards net autotrophy in the summer. Ongoing trends of SAV loss in this and other back-barrier estuaries suggest that these systems may also shift towards net heterotrophy, reducing their effectiveness as long-term carbon sinks. With regards to temporal variability, we found that varying sampling frequency between 15 min and 1 d resulted in comparable mean values of biogeochemical variables, but extreme values were missed by daily sampling. In fact, daily resampling minimized the variability between sites and falsely suggested spatial homogeneity in biogeochemistry, emphasizing the need for high-frequency sampling. This study confirms that properly quantifying ecosystem metabolism and associated biogeochemical variability requires characterization of the diverse estuarine environments, even in well-mixed systems, and demonstrates the deficiencies introduced by infrequent sampling to the interpretation of spatial variability.

scholarly journals Water Quality Properties Derived from VIIRS Measurements in the Great Lakes

2020 ◽  
Vol 12 (10) ◽  
pp. 1605
Author(s):  
Seunghyun Son ◽  
Menghua Wang
Keyword(s):  
Water Quality ◽  
Great Lakes ◽  
Lake Erie ◽  
Infrared Imaging ◽  
Seasonal Pattern ◽  
Secchi Depth ◽  
Phytoplankton Production ◽  
Quality Properties ◽  
Chl A ◽  
Freshwater Inputs

Refined empirical algorithms for chlorophyll-a (Chl-a) concentration, using the maximum ratio of normalized water-leaving radiance nLw(λ) at the blue and green bands, and Secchi depth (SD) from nLw(λ) at 551 nm, nLw(551), are proposed for the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite in the Great Lakes. We demonstrated that water quality properties and phytoplankton production can be successfully monitored and assessed using the new regional Chl-a and SD algorithms, with reasonably accurate estimates of Chl-a and SD from the VIIRS-SNPP ocean color data in the Great Lakes. VIIRS-derived Chl-a and SD products using the proposed algorithms provide the temporal and spatial variabilities in the Great Lakes. Overall, Chl-a concentrations are generally low in lakes Michigan and Huron, while Chl-a data are highest in Lake Erie. The seasonal pattern shows that overall low Chl-a concentrations appear in winter and high values in June to September in the lakes. The distribution of SD in the Great Lakes is spatially and temporally different from that of Chl-a. The SD data are generally lower in summer and higher in winter in most of the Great Lakes. However, the highest SD in Lake Erie appears in summer, and lower values in winter. Significantly high values in Chl-a, and lower values in SD, in the nearshore regions, such as Thunder Bay, Saginaw Bay, and Whitefish Bay, can be related to the very shallow bathymetry and freshwater inputs from the land. The time series of VIIRS-derived Chl-a and SD data provide strong interannual variability in most of the Great Lakes.

scholarly journals Small phytoplankton contribution to the standing stocks and the total primary production in the Amundsen Sea

2017 ◽  
Vol 14 (15) ◽  
pp. 3705-3713 ◽  
Author(s):  
Sang H. Lee ◽  
Bo Kyung Kim ◽  
Yu Jeong Lim ◽  
HuiTae Joo ◽  
Jae Joong Kang ◽  
...  
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Nitrogen Uptake ◽  
Total Carbon ◽  
Phytoplankton Production ◽  
Carbon Uptake ◽  
Amundsen Sea ◽  
Carbon And Nitrogen ◽  
Uptake Rates ◽  
Small Phytoplankton

Abstract. Small phytoplankton are anticipated to be more important in a recently warming and freshening ocean condition. However, little information on the contribution of small phytoplankton to overall phytoplankton production is currently available in the Amundsen Sea. To determine the contributions of small phytoplankton to total biomass and primary production, carbon and nitrogen uptake rates of total and small phytoplankton were obtained from 12 productivity stations in the Amundsen Sea. The daily carbon uptake rates of total phytoplankton averaged in this study were 0.42 g C m−2 d−1 (SD  =  ± 0.30 g C m−2 d−1) and 0.84 g C m−2 d−1 (SD  =  ± 0.18 g C m−2 d−1) for non-polynya and polynya regions, respectively, whereas the daily total nitrogen (nitrate and ammonium) uptake rates were 0.12 g N m−2 d−1 (SD  =  ± 0.09 g N m−2 d−1) and 0.21 g N m−2 d−1 (SD  =  ± 0.11 g N m−2 d−1), respectively, for non-polynya and polynya regions, all of which were within the ranges reported previously. Small phytoplankton contributed 26.9 and 27.7 % to the total carbon and nitrogen uptake rates of phytoplankton in this study, respectively, which were relatively higher than the chlorophyll a contribution (19.4 %) of small phytoplankton. For a comparison of different regions, the contributions for chlorophyll a concentration and primary production of small phytoplankton averaged from all the non-polynya stations were 42.4 and 50.8 %, which were significantly higher than those (7.9 and 14.9 %, respectively) in the polynya region. A strong negative correlation (r2 = 0. 790, p<0. 05) was found between the contributions of small phytoplankton and the total daily primary production of phytoplankton in this study. This finding implies that daily primary production decreases as small phytoplankton contribution increases, which is mainly due to the lower carbon uptake rate of small phytoplankton than large phytoplankton.

Contribution of Particulate Phosphorus (> 250 μm) to the Total Phosphorus Pool in Lake Water

1984 ◽  
Vol 41 (2) ◽  
pp. 351-363 ◽  
Author(s):  
E. E. Prepas ◽  
J. Vickery
Keyword(s):  
Chlorophyll A ◽  
Total Phosphorus ◽  
Lake Water ◽  
Euphotic Zone ◽  
Particulate Phosphorus ◽  
Lake Productivity ◽  
Chl A ◽  
Relative Contribution ◽  
Residual Variation ◽  
Large Particles

Particulate phosphorus (PP) > 250 μm was concentrated in the euphotic zone of 17 lakes in central Alberta. When the euphotic zone extended below the epilimnion, PP >250 μm was concentrated deep in the euphotic zone. PP > 250 μm was a significant but variable portion of the total phosphorus (TP) pool in individual lakes; thus, samples should be collected from the euphotic zone on several dates to estimate the contribution of PP > 250 μm to the TP pool. As well, the contribution of this fraction varied among lakes: average summer values for the euphotic zone ranged from 3 to 19%. Among lakes, the contribution of large particles to the TP pool decreased proportionally as lake productivity (estimated by chlorophyll a (Chl a)) increased. The relative contribution of PP > 250 μm in summer accounted for a significant portion of the residual variation in the spring TP-summer Chl a relationship but not the summer TP-summer Chl a relationship in the study lakes. These apparently contradictory results can be explained by differences between lakes that mixed intermittently throughout the summer and those that remained permanently thermally stratified during this time.

Effects of a fluctuation in Fraser River discharge of primary production in the central Strait of Georgia, British Columbia, Canada

1997 ◽  
Vol 54 (5) ◽  
pp. 1015-1024 ◽  
Author(s):  
K Yin ◽  
P J Harrison ◽  
R J Beamish
Keyword(s):  
British Columbia ◽  
Primary Production ◽  
River Discharge ◽  
Euphotic Zone ◽  
Early Summer ◽  
Phytoplankton Production ◽  
Fraser River ◽  
Strait Of Georgia ◽  
Chl A ◽  
First Time

High-resolution vertical profiles of salinity, temperature, fluorescence, and nutrients (NO3 and SiO4) were taken along a transect in the central Strait of Georgia, British Columbia. The Fraser River discharge increased rapidly over 4 days and then decreased over the following 3 days (June 16-19, 1991). The thickness and extent of the estuarine plume increased as a response to the increased river discharge. As the estuarine plume flowed seaward, the nutricline (NO3) became shallower and broader, resulting in an increase in NO3 in the euphotic zone. Entrainment of NO3 may explain the increase in NO3 in the surface layer, and the amount of NO3 entrained was estimated to be 5-10 times higher than river-borne NO3. The utilization of entrained nutrients increased Chl a concentrations and primary production to levels comparable with spring bloom values. Our results clearly demonstrated for the first time that entrainment of nutrients and phytoplankton production in the central Strait of Georgia are closely coupled to fluctuations in the Fraser River discharge as the estuarine plume moves seaward. The timing and magnitude of the May-June freshet could control the entrainment of nutrients and thus maintain high primary productivity in late spring - early summer.

Primary Production in Lakes Ontario and Erie: A Comparative Study

1974 ◽  
Vol 31 (3) ◽  
pp. 253-263 ◽  
Author(s):  
Walter A. Glooschenko ◽  
James E. Moore ◽  
Mohiuddin Munawar ◽  
R. A. Vollenweider
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Lake Erie ◽  
Lake Ontario ◽  
Early Summer ◽  
Central Basin ◽  
Western Basin ◽  
Eastern Basin ◽  
Production Values ◽  
Rate Of Increase

Primary production values in Lake Ontario were low in winter, reached a maximum in midspring, declined during summer, and slightly increased in fall. Rate of increase of production for inshore waters (< 20 m depth) was greater especially in spring and early summer with a greater maximum reached earlier than in offshore waters. Assimilation numbers, mgC fixed/mg chlorophyll a per hour, in Lake Ontario were fairly constant over the lake with a yearly range of 1.2–1.6. Primary production showed a linear relationship to chlorophyll a concentration, as also occurred in Lake Erie.Lake Erie primary production varied in its three basins. Seasonally, in the Eastern Basin, production was highest in spring with a midsummer decline, and small peaks in fall. The Western Basin had a maximum in midsummer whereas the Central Basin had peaks in late summer and early fall. Assimilation numbers were highest in the Western Basin (up to 3.5 mgC/mg chlorophyll a per hour) and lowest in the mid-Central Basin and Eastern Basin with values of approximately 1.4 mgC/mg chlorophyll a per hour. A definite westerly increase of assimilation number was observed.Up to early summer, the two lakes were fairly equal in surface production but integral photosynthesis, mgC/m2 per hour was higher in Lake Ontario than in Lake Erie. The same was valid in November and December. In summer, Lake Erie was higher in production on both a mgC/m3 per hour and mgC/m2 per hour basis. For the period, April–December, Lake Ontario's total estimated yield was 170 gC/m2, whereas for Lake Erie values of 160, 210, and 310 gC/m2 were found for the Eastern, Central, and Western basins, respectively.

Chlorophyll–Phosphorus Relationships for Subarctic Lakes in Western Canada

1987 ◽  
Vol 44 (4) ◽  
pp. 775-781 ◽  
Author(s):  
M. L. Ostrofsky ◽  
F. H. Rigler
Keyword(s):  
British Columbia ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Chlorophyll Concentration ◽  
Yukon Territory ◽  
Western Canada ◽  
Subarctic Lakes ◽  
Empirical Relationships ◽  
Chl A ◽  
The Relationship

Concentrations of total phosphorus and chlorophyll a were measured weekly in 49 lakes in the vicinity of Yellowknife, N.W.T., Canada, from May to September 1977. The relationship between [TPspr] and [Chl asu] was significantly different from the Dillon–Rigler model, but similar to relationships developed for lakes in Alberta, British Columbia, and the Yukon Territory. Empirical relationships were developed between [TPspr] and maximum chlorophyll a concentrations and the probability of exceeding critical concentrations of chlorophyll a. These models may be potentially more useful than models which predict only a mean summer chlorophyll concentration.

Bacterial abundance and production, and their relation to primary production in tropical coastal waters of Peninsular Malaysia

2008 ◽  
Vol 59 (1) ◽  
pp. 10 ◽  
Author(s):  
Choon Weng Lee ◽  
Chui Wei Bong
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Coastal Waters ◽  
Bacterial Production ◽  
Bacterial Abundance ◽  
Net Primary Production ◽  
Correlation Coefficients ◽  
Peninsular Malaysia ◽  
Chl A ◽  
The Relationship

In the present study, the relationship between bacteria and phytoplankton in tropical coastal waters was investigated. The bacterial abundance, bacterial production, chlorophyll a concentration and net primary production were measured at several locations in the coastal waters of Peninsular Malaysia. Chlorophyll a concentration ranged from 0.40 to 32.81 μg L–1, whereas bacterial abundance ranged from 0.1 to 97.5 × 106 cells mL–1. Net primary production ranged from 8.49 to 55.95 μg C L–1 h–1, whereas bacterial production ranged from 0.17 to 70.66 μg C L–1 h–1. In the present study, the carbon conversion factor used to convert bacterial production (cells mL–1 h–1) into carbon units ranged from 10 to 32.8 fg C cell–1, and was estimated from the bacterial size distribution measured at each location. Both phototrophic and heterotrophic biomass (bacteria–chlorophyll a) and activity (bacterial production–net primary production) were significantly correlated, although their correlation coefficients (r2) were relatively low (r2 = 0.188 and r2 = 0.218 respectively). Linear regression analyses provided the following equations to represent the relationship between: bacteria and chlorophyll a (Chl a), log Bacteria = 0.413 log Chl a + 6.057 (P = 0.003); and between bacterial production (BP) and net primary production (NPP), log BP = 0.896 log NPP – 0.394 (P = 0.004), which fitted with published results well. Comparison of annual carbon fluxes confirmed the prevalence of net heterotrophy in these coastal waters, and together with the low correlation coefficients, suggested the role of allochthonous organic matter in supporting heterotrophic activity.

scholarly journals Spatiotemporal variability of light attenuation and net ecosystem metabolism in a back-barrier estuary

2019 ◽  
Author(s):  
Neil K. Ganju ◽  
Jeremy M. Testa ◽  
Steven E. Suttles ◽  
Alfredo L. Aretxabaleta
Keyword(s):  
Dissolved Oxygen ◽  
Primary Production ◽  
Chlorophyll A ◽  
Submerged Aquatic Vegetation ◽  
Aquatic Vegetation ◽  
Light Attenuation ◽  
Sediment Resuspension ◽  
Ecosystem Metabolism ◽  
Net Ecosystem Metabolism

Abstract. Quantifying system-wide biogeochemical dynamics and ecosystem metabolism in estuaries is often attempted using a long-term continuous record at a single site, or short-term records at multiple sites due to sampling limitations that preclude long-term monitoring at multiple sites. However, differences in the dominant primary producer at a given location (e.g., phytoplankton versus submerged aquatic vegetation; SAV) control diel variations in dissolved oxygen and associated ecosystem metabolism, and may confound metabolism estimates that do not account for this variability. We hypothesize that even in shallow, well-mixed estuaries there are strong spatiotemporal gradients in ecosystem metabolism due to the influence of submerged aquatic vegetation (SAV), and ensuing feedbacks to sediment resuspension, light attenuation, and primary production. We tested this hypothesis by measuring hydrodynamic properties, biogeochemical variables (fluorescent dissolved organic matter (fDOM), turbidity, chlorophyll-a fluorescence, dissolved oxygen), and photosynthetically active radiation (PAR) over one year at 15 min intervals at paired channel (unvegetated) and shoal (vegetated) sites in Chincoteague Bay, Maryland/Virginia, USA, a shallow back-barrier estuary. Light attenuation (KdPAR) at all sites was dominated by turbidity from suspended sediment, with lower contributions from fDOM and chlorophyll-a. However, there was significant seasonal variability in the resuspension-shear stress relationship on the vegetated shoals, but not in adjacent unvegetated channels. This indicated that KdPAR on the shoals was mediated by SAV presence in the summer, which reduced resuspension and therefore KdPAR. We also found that gross primary production (Pg) and KdPAR were significantly negatively correlated on the shoals and uncorrelated in the channels, indicating that Pg over the vegetated shoals is controlled by a feedback loop between SAV presence, sediment resuspension, and light availability. Metabolic estimates indicated substantial differences in net ecosystem metabolism between vegetated and unvegetated sites, with the former tending towards net autotrophy in the summer. Ongoing trends of SAV loss in this and other back-barrier estuaries suggests that these systems may also shift towards net heterotrophy, reducing their effectiveness as long-term carbon sinks. With regard to temporal variability, we found that varying sampling frequency between 15 min and 1 d resulted in comparable mean values of biogeochemical variables, but extreme values were missed by daily sampling. In fact, daily re-sampling minimized the variability between sites and falsely suggested spatial homogeneity in biogeochemistry, emphasizing the need for high-frequency sampling. This study confirms that properly quantifying ecosystem metabolism and associated biogeochemical variability requires characterization of the diverse estuarine environments, even in well-mixed systems, and demonstrates the deficiencies introduced by infrequent sampling on the interpretation of spatial gradients.

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