Dynamics of Lake Michigan Phytoplankton: Primary Production and Growth

1987 ◽  
Vol 44 (3) ◽  
pp. 499-508 ◽  
Author(s):  
Gary L Fahnenstiel ◽  
Donald Scavia
Keyword(s):  
Primary Production ◽  
Thermal Stratification ◽  
Lake Michigan ◽  
Production Model ◽  
Daily Production ◽  
Model Estimate ◽  
Phytoplankton Primary Production ◽  
Net Production ◽  
Assimilation Number

Primary production was measured with the 14C technique during May through July–August 1982–84. 14C experiments varied from short-term incubations (1–2 h) in a photosynthesis–irradiance (P–I) chamber to 24-h in situ incubations. The maximum assimilation number from six P–I experiments during thermal stratification averaged 2.1 mg C∙mg Chl−1∙h−1 which agreed well with estimates from the 1970s. Chlorophyll-corrected P–I curves were combined with incident irradiation, chlorophyll concentrations, and extinction coefficients to estimate daily production (model estimate). Summer average integral production estimates in 1983 and 1984 were 615–630 mg C∙m−2∙d−1. Approximately 50% of summer primary production occurred below the epilimnion. Daily model production estimates were higher than 24-h in situ estimates at light intensities above Ik, the light saturation parameter, and similar at intensities below Ik. Comparisons of production estimates converted to growth rates suggest that 24-h in situ estimates provide a measure close to net production whereas model estimates provide a measure greater than net production. Summer epilimnetic growth rate estimates were low (range 0.06–0.60∙d−1), reflecting the limited availability of phosphorus.

scholarly journals A 55-Year Time Series Station for Primary Production in the Adriatic Sea: Data Correction, Extraction of Photosynthesis Parameters and Regime Shifts

2018 ◽  
Vol 10 (9) ◽  
pp. 1460 ◽  
Author(s):  
Žarko Kovač ◽  
Trevor Platt ◽  
Živana Ninčević Gladan ◽  
Mira Morović ◽  
Shubha Sathyendranath ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Primary Production ◽  
Water Column ◽  
Seasonal Cycle ◽  
Adriatic Sea ◽  
Remotely Sensed ◽  
Linear Extrapolation ◽  
Daily Production ◽  
Assimilation Number

In 1962, a series of in situ primary production measurements began in the Adriatic Sea, at a station near the island of Vis. To this day, over 55 years of monthly measurements through the photic zone have been accumulated, including close to 3000 production measurements at different depths. The measurements are conducted over a six-hour period around noon, and the average production rate extrapolated linearly over day length to calculate daily production. Here, a non-linear primary production model is used to correct these estimates for potential overestimation of daily production due to linear extrapolation. The assimilation numbers are recovered from the measured production profiles and subsequently used to model production at depth. Using the recovered parameters, the model explained 87% of variability in measured normalized production at depth. The model is then used to calculate daily production at depth, and it is observed to give on average 20% lower daily production at depth than the estimates based on linear extrapolation. Subsequently, water column production is calculated, and here, the model predicted on average 26% lower water column production. With the recovered parameters and the known magnitude of the overestimation, the time-series of water column production is then re-established with the non-linearly-corrected data. During this 55-year period, distinct regimes were observed, which were classified with a regime shift detection method. It is then demonstrated how the recovered parameters can be used in a remote sensing application. A seasonal cycle of the recovered assimilation number is constructed along with the seasonal cycle of remotely-sensed chlorophyll. The two are then used to model the seasonal cycle of water column production. An upper and a lower bound on the seasonal cycle of water column production based on remotely-sensed chlorophyll data are then presented. Measured water column production was found to be well within the range of remotely-sensed estimates. With this work, the utility of in situ measurements as a means of providing information on the assimilation number is presented and its application as a reference for remote sensing models highlighted.

Modelling Primary Production in Water Bodies: A Numerical Approach that Allows Vertical Inhomogeneities

1973 ◽  
Vol 30 (10) ◽  
pp. 1469-1473 ◽  
Author(s):  
Everett J. Fee
Keyword(s):  
Primary Production ◽  
Algal Biomass ◽  
Numerical Approach ◽  
Light Responses ◽  
Phytoplankton Primary Production ◽  
Basic Approach ◽  
Mathematical Solution ◽  
Model Predictions ◽  
Vertical Variations

A new model for computing integral daily phytoplankton primary production is described. The model incorporates vertical variations of algal biomass, complex photosynthesis vs. light responses, nonexponential extinction of light vs. depth, and any distribution of surface light over a day. The basic approach is to combine measured relations for photosynthetic rate vs. light, light vs. depth, and light vs. time in an interpolative scheme rather than attempting to fit equations to the data and using the resulting equations to obtain a mathematical solution. The model is general and should have wide applicability. Model predictions agreed well with in situ measurements of production.

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 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.

scholarly journals Validation of a Primary Production Algorithm of Vertically Generalized Production Model Derived from Multi-Satellite Data around the Waters of Taiwan

2020 ◽  
Vol 12 (10) ◽  
pp. 1627
Author(s):  
Kuo-Wei Lan ◽  
Li-Jhih Lian ◽  
Chun-Huei Li ◽  
Po-Yuan Hsiao ◽  
Sha-Yan Cheng
Keyword(s):  
Primary Production ◽  
Production Model ◽  
Dark Bottle ◽  
Kuroshio Water ◽  
Chl A ◽  
Basin Scale ◽  
Mean Square Difference ◽  
The Kuroshio ◽  
China Coast

Basin-scale sampling for high frequency oceanic primary production (PP) is available from satellites and must achieve a strong match-up with in situ observations. This study evaluated a regionally high-resolution satellite-derived PP using a vertically generalized production model (VGPM) with in situ PP. The aim was to compare the root mean square difference (RMSD) and relative percent bias (Bias) in different water masses around Taiwan. Determined using light–dark bottle methods, the spatial distribution of VGPM derived from different Chl-a data of MODIS Aqua (PPA), MODIS Terra (PPT), and averaged MODIS Aqua and Terra (PPA&T) exhibited similar seasonal patterns with in situ PP. The three types of satellite-derived PPs were linearly correlated with in situ PPs, the coefficients of which were higher throughout the year in PPA&T (r2 = 0.61) than in PPA (r2 = 0.42) and PPT (r2 = 0.38), respectively. The seasonal RMSR and bias for the satellite-derived PPs were in the range of 0.03 to 0.09 and −0.14 to −0.39, respectively, which suggests the PPA&T produces slightly more accurate PP measurements than PPA and PPT. On the basis of environmental conditions, the subareas were further divided into China Coast water, Taiwan Strait water, Northeastern upwelling water, and Kuroshio water. The VPGM PP in the four subareas displayed similar features to Chl-a variations, with the highest PP in the China Coast water and lowest PP in the Kuroshio water. The RMSD was higher in the Kuroshio water with an almost negative bias. The PPA exhibited significant correlations with in situ PP in the subareas; however, the sampling locations were insufficient to yield significant results in the China Coast water.

A Numerical Model for Determining Integral Primary Production and its Application to Lake Michigan

1973 ◽  
Vol 30 (10) ◽  
pp. 1447-1468 ◽  
Author(s):  
Everett J. Fee
Keyword(s):  
Primary Production ◽  
Lake Michigan ◽  
Model Parameters ◽  
Time Interval ◽  
Actual Distribution ◽  
In Situ Experiments ◽  
Routine Basis ◽  
Computer Based ◽  
Large Water

A computer-based model for determining production by phytoplankton, integrated over depth and over an arbitrary time interval, is described. The solution incorporates light inhibition and uses the actual distribution of surface irradiance for the time interval of interest, since it is not possible to predict the detailed nature of cloudiness. Statistical procedures for estimating the model parameters from experimental data relating the rate of carbon uptake to irradiance are described. The model is applied to data collected from May 27, 1970 through February 3, 1971 from Lake Michigan.Integral primary production was bimodal at inshore and offshore stations with minimum production in midsummer and winter. There was great daily variability of integral production, due solely to variation of light. From this it is inferred that occasional in situ measurements would give a very poor knowledge of true seasonal trends.The model output was verified by performing two in situ experiments. The agreement was better than 95% on both dates. The model makes it possible to estimate integral primary production on a routine basis in large water bodies with well-mixed photic zones.

scholarly journals Preliminary Investigation on Phytoplankton Dynamics and Primary Production Models in an Oligotrophic Lake from Remote Sensing Measurements

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5072
Author(s):  
Ilaria Cesana ◽  
Mariano Bresciani ◽  
Sergio Cogliati ◽  
Claudia Giardino ◽  
Remika Gupana ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Primary Production ◽  
Preliminary Investigation ◽  
Fluorescence Emission ◽  
Phytoplankton Primary Production ◽  
Chl A ◽  
Production Models ◽  
Solar Noon ◽  
Lake Waters

The aim of this study is to test a series of methods relying on hyperspectral measurements to characterize phytoplankton in clear lake waters. The phytoplankton temporal evolutions were analyzed exploiting remote sensed indices and metrics linked to the amount of light reaching the target (EPAR), the chlorophyll-a concentration ([Chl-a]OC4) and the fluorescence emission proxy. The latter one evaluated by an adapted version of the Fluorescence Line Height algorithm (FFLH). A peculiar trend was observed around the solar noon during the clear sky days. It is characterized by a drop of the FFLH metric and the [Chl-a]OC4 index. In addition to remote sensed parameters, water samples were also collected and analyzed to characterize the water body and to evaluate the in-situ fluorescence (FF) and absorbed light (FA). The relations between the remote sensed quantities and the in-situ values were employed to develop and test several phytoplankton primary production (PP) models. Promising results were achieved replacing the FA by the EPAR or FFLH in the equation evaluating a PP proxy (R2 > 0.65). This study represents a preliminary outcome supporting the PP monitoring in inland waters by means of remote sensing-based indices and fluorescence metrics.

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