Remedial strategy of algal proliferation in a regulated river system by integrated hydrological control: an evolutionary modelling framework

2014 ◽  
Vol 65 (5) ◽  
pp. 379 ◽  
Author(s):  
Dong-Gyun Hong ◽  
Kwang-Seuk Jeong ◽  
Dong-Kyun Kim ◽  
Gea-Jae Joo
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
River Flow ◽  
Winter Season ◽  
River System ◽  
Regulated River ◽  
Water Volume ◽  
Ample Evidence ◽  
Chlorophyll A Concentration ◽  
Rule Set

We simulated water-quality measures in a regulated river system (the lower Nakdong River) under simultaneous discharge control at upriver dams and an estuarine barrage with the goal of reducing phytoplankton biomass (chlorophyll a concentration). We used genetic programming (GP) to create a rule-set-based predictive model for the chlorophyll a concentration based on 16 years (1994–2009) of meteorological, hydrological, and limnological data. The rule-set model used eight variables, including water temperature, dam and estuarine barrage discharge, phosphate and silica concentrations, and accurately predicted the phytoplankton biomass (determination coefficients, r2, for training and test data were 0.52 and 0.45, respectively). According to sensitivity and scenario analyses, a larger water volume resulting from increased discharge from upriver dams and decreased discharge from an estuarine barrage would reduce chlorophyll a concentrations at the study site. This result provided ample evidence that simultaneous manipulation of dam and estuarine discharge rates could effectively increase river flow and flush aggregated algal populations downstream. Additionally, we considered that even small increases in river flow could play a role in diluting phytoplankton biomass during the dry winter season when estuarine discharge remains low. These two hydrological mechanisms could be used as selective strategies for water-resource management.

Measurements of Phytoplankton Absorption Other Than Per Unit of Chlorophyll a

Ocean Optics ◽  
1994 ◽  
Author(s):  
Mary Jane Perry
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Photosynthetic Pigments ◽  
Critical Role ◽  
Specific Effect ◽  
Water Volume ◽  
Phytoplankton Abundance ◽  
Chlorophyll A Concentration ◽  
Total Irradiance ◽  
Phytoplankton Absorption

Phytoplankton plays a critical role in determining light fields of the world’s oceans, primarily through absorption of light by photosynthetic pigments (see Chapters 1 to 5). Consequently there has been considerable interest from optical researchers in determining phytoplankton absorption. Conversely, from the biological point of view, this absorption assumes paramount importance because it is the sole source of energy for photosynthesis and thus should be central to direct estimates of primary production. There are two logical parts in determining this effect of phytoplankton and in estimating primary production. One is the estimation of abundance, and the other is estimation of specific effect or specific production rate. The earliest estimates of phytoplankton abundance were based on cell counts. From the time of Francis A. Richards’ Ph.D. dissertation, however, measurement of chlorophyll a concentration per unit of water volume, because of its relative ease, has assumed a central role in abundance estimation. Physiological studies and technological advances in optical instrumentation over the last decade lead me to question whether the continued use of chlorophyll a concentration to estimate phytoplankton abundance was wise either from the viewpoint of narrowing confidence intervals on estimates of absorption and production or from the viewpoint of mechanistic understanding of the processes involved. The measurement of chlorophyll a has become such a routine tool of biological oceanography, however, that the reasons for my heresy require elaboration. Some of the reasons are not too subtle. Chlorophyll a exists with other photosynthetic pigments in organized arrays associated with photosynthetic membranes. The function of these arrays is to harvest photons and transfer their energy to the specialized reaction center complexes that mediate photochemistry (see Chapter 9). The size of the arrays or packages and the ratio of chlorophyll a molecules to other light-harvesting pigments within the packages vary with phytoplankton cell size, total irradiance and its spectral distribution, as well as with other environmental parameters. It is well known that dark-adapted (= light-limited) cells increase their complements of photopigments. This plasticity in pigment packaging is evidenced in the variability of chlorophyll a-specific absorption coefficients. Simple optical models based only on chlorophyll a concentrations cannot be accurate or precise unless the effects of pigment packaging are considered.

scholarly journals Vertical distribution of chlorophyll <I>a</I> concentration and phytoplankton community composition from in situ fluorescence profiles: a first database for the global ocean

2015 ◽  
Vol 7 (2) ◽  
pp. 261-273 ◽  
Author(s):  
R. Sauzède ◽  
H. Lavigne ◽  
H. Claustre ◽  
J. Uitz ◽  
C. Schmechtig ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Chlorophyll A ◽  
Community Composition ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
Environmental Data ◽  
Global Ocean ◽  
Control Procedure ◽  
Chlorophyll A Concentration ◽  
Phytoplankton Community Composition

Abstract. In vivo chlorophyll a fluorescence is a proxy of chlorophyll a concentration, and is one of the most frequently measured biogeochemical properties in the ocean. Thousands of profiles are available from historical databases and the integration of fluorescence sensors to autonomous platforms has led to a significant increase of chlorophyll fluorescence profile acquisition. To our knowledge, this important source of environmental data has not yet been included in global analyses. A total of 268 127 chlorophyll fluorescence profiles from several databases as well as published and unpublished individual sources were compiled. Following a robust quality control procedure detailed in the present paper, about 49 000 chlorophyll fluorescence profiles were converted into phytoplankton biomass (i.e., chlorophyll a concentration) and size-based community composition (i.e., microphytoplankton, nanophytoplankton and picophytoplankton), using a method specifically developed to harmonize fluorescence profiles from diverse sources. The data span over 5 decades from 1958 to 2015, including observations from all major oceanic basins and all seasons, and depths ranging from the surface to a median maximum sampling depth of around 700 m. Global maps of chlorophyll a concentration and phytoplankton community composition are presented here for the first time. Monthly climatologies were computed for three of Longhurst's ecological provinces in order to exemplify the potential use of the data product. Original data sets (raw fluorescence profiles) as well as calibrated profiles of phytoplankton biomass and community composition are available on open access at PANGAEA, Data Publisher for Earth and Environmental Science. Raw fluorescence profiles: http://doi.pangaea.de/10.1594/PANGAEA.844212 and Phytoplankton biomass and community composition: http://doi.pangaea.de/10.1594/PANGAEA.844485

Productivity of the Psammic Algal Communities in the Near-Shore Zone of the Mesotrophic Lake Piaseczno (Eastern Poland)

2001 ◽  
Vol 36 (3) ◽  
pp. 537-564 ◽  
Author(s):  
Krzysztof Czernaś
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Major Ions ◽  
Shore Zone ◽  
Algal Communities ◽  
Chlorophyll A Concentration ◽  
Assimilation Number ◽  
Mesotrophic Lake ◽  
Near Shore

Abstract From 1986 to 1998, the primary productivity of psammic algae was investigated in the psammolittoral of Lake Piaseczno, a mesotrophic lake. The oxygen method was developed for the direct measurement of primary production of these algae based on light and dark bottles without disturbing the subsoil structure. This productivity was also estimated in an indirect way by measurement of chlorophyll a concentrations. The productivity of phytoplankton was also measured in the same zone. The correlation between the productivity of algae and the concentration of nutrients and major ions in water was calculated. During the study period, the highest production was found in the eupsammon (31.1 to 187.7 Cass·m-2·h-1), with the hydropsammon being lower (9.6 to 100.6 Cass·m-2·h-1). For phytoplankton biomass, the numbers were very low, which is typical of pristine lakes. The chlorophyll a concentration during the study period demonstrated a different pattern ranging from 53 mg·m-2 in the hydropsammon to 765 mg·m-2 in the eupsammon. The assimilation number for these communities was always &lt;1. A positive (r &gt;0.4) correlation was found between the primary production of the eupsammon and the psammolittoral phytoplankton, and the concentration of NH4-N, NO3-N, Ntot, PO4-P, Ptot. and K+ in the piezometer groundwater. No correlation was found between primary production, chlorophyll a concentration and the concentration of nutrients and major ions in the piezometer groundwater and psammolittoral water.

Temperature Rising (Two Celsius) Effect on Planktonic Biomass in Subtropical Marshes, Iraq

2021 ◽  
Vol 5 (1) ◽  
pp. 44-52
Author(s):  
Mohammed Al-Haidarey
Keyword(s):  
Climate Change ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Large Scale ◽  
Dissolved Inorganic Carbon ◽  
Winter Season ◽  
Heating System ◽  
Early Spring ◽  
Natural Sediment ◽  
Lake Ecosystems

Planktonic species may respond to climate change through their niche across three axes which include self, space and time. This study was designed to investigate the effect of increasing winter temperature on the plankton biomass, the mesocosm was constructed as a collection of 16 enclosures with a water-outlet system and natural sediment, two aquatic plant species and heating system. This research was conducted over 12 weeks (beginning on Dec. 2018) when the temperature of eight enclosures was 2±0.2 °C higher than the ambient temperature. Weekly abiotic parameters (salinity, pH, PO4, NO3, DIC) and biotic (chlorophyll-a, zooplankton and phytoplankton biomass) were reported. The obtained results showed that there were no major improvements in salinity, pH, PO4, NO3 and dissolved inorganic carbon (DIC). Whereas, chlorophyll-a, zooplankton and phytoplankton biomass have dramatically improved. Therefore, this research has indicated that water temperature change during the winter season due to climate change could affect planktonic biomass and early spring in subtropical marshes, but this study was performed in the mesocosm experiment and it needs to be studied in large-scale natural lake ecosystems.

scholarly journals Chlorophyll a concentration across a trophic gradient of lakes: An estimator of phytoplankton biomass?

Limnologica ◽  
2008 ◽  
Vol 38 (3-4) ◽  
pp. 327-338 ◽  
Author(s):  
Peter Kasprzak ◽  
Judit Padisák ◽  
Rainer Koschel ◽  
Lothar Krienitz ◽  
Frank Gervais
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Trophic Gradient ◽  
Chlorophyll A Concentration

scholarly journals Assessment of chlorophyll-a and sea surface temperature variability around the Mascarene Plateau, Nazareth Bank (Mauritius) using satellite data

2017 ◽  
Vol 64 (4) ◽  
Author(s):  
V. Ramchandur ◽  
Soonil D. D. V. Rughooputh ◽  
R. Boojawon ◽  
B. A. Motah
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Chlorophyll A ◽  
Satellite Data ◽  
Phytoplankton Biomass ◽  
Winter Season ◽  
Sea Surface ◽  
Chl A ◽  
The Past ◽  
Western Side

The Mascarene Plateau is characterised by shallow banks namely Saya de Malha and Nazareth which are known to harbour high phytoplankton biomass along the slope down to the ridge. Correlation between sea surface temperature (SST) and Chlorophyll-a (Chl-a) distribution surrounding the plateau was investigated. Higher Chl-a concentration was observed during the period July to September, indicating higher productivity due to upwelling. The regions east (61-630E) and west (57-590E) of the Mascarene Plateau were also studied along latitudes 130S up to 180S in the exclusive economic zone of Mauritius, where most of the fishing activities are concentrated. In general, 2008 was observed to be less warm during the past 14 years registering a drop with respect to the maximum monthly mean records, whilst 2006 was the most productive during winter season in the region of study. Chl-a bloom was observed after cyclone Imelda in April 2013 showing Chl-a concentration above 0.3 mg m-3 along latitude 130S and longitude 570E. The study reveals that the western side of the plateau is more productive with relatively warmer surface temperature compared to the eastern side of the plateau.

scholarly journals Akumulasi Biomasa Fitoplankton yang Diukur sebagai Klorofil-a di Perairan Teluk Doreri, Provinsi Papua Barat

2020 ◽  
Vol 23 (2) ◽  
pp. 247-254
Author(s):  
Alianto Alianto ◽  
Yorry Kambanussy ◽  
Luky Sembel ◽  
Baigo Hamuna
Keyword(s):  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Water Sampling ◽  
Chlorophyll A Concentration ◽  
Measurement Results ◽  
West Papua ◽  
Papua Barat ◽  
Negative Relationships

The accumulation of phytoplankton biomass measured as chlorophyll-a is highly depends on the availability of ammonia and silicate in the waters. The purpuses of the study were examining the concentration of chlorophyll-a and its relation with ammonia and silicate in the waters of Doreri Bay, Manokwari Regency, West Papua Province. Water sampling is carried out at 10 stations. Parameters measured include chlorophyll-a, ammonia and silicate. The measurement results of chlorophyll-a concentration ranged from 0.23-3.77 μg/L with an meanof 0.82 μg/L. Ammonia and silicate concentrations ranged from 2.35-4.11 μM with an mean of 2.64 μM and 2.00-7.50 μM with an mean of 3.91 μM, respectively. The relationships of chlorophyll-a concentration with ammonia and silicate showed positive and negative relationships, respectively.  Akumulasi biomasa fitoplankton yang diukur sebagai klorofil-a sangat tergantung pada ketersediaan amonia dan silikat di perairan. Penelitian bertujuan untuk mengetahui konsentrasi klorofil-a serta hubungannya dengan amonia dan silikat di perairan Teluk Doreri, Kabupaten Manokwari, Provinsi Papua Barat. Pengambilan contoh air dilakukan pada 10 stasiun. Parameter yang diukur meliputi klorofil-a, amonia dan silikat. Hasil pengukuran konsentrasi klorofil-a berkisar dari 0,23-3,77 μg/L dengan rata-rata sebesar 0,82 μg/L. Konsentrasi amonia dan silikat secara berturut-turut berkisar dari 2,35-4,11 μM dengan rata-rata sebesar 2,64 μM dan 2,00-7,50 μM dengan rata-rata sebesar 3,91μM. Hubungan konsentrasi klorofil-a dengan amonia dan silikat secara berturut-turut menunjukkan hubungan positif dan negatif. 

scholarly journals High chlorophyll a concentration in a low nutrient context: discussions in a subtropical lake dominated by Cyanobacteria

2016 ◽  
Author(s):  
Mariana C. Hennemann ◽  
Mauricio M. Petrucio
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Cylindrospermopsis Raciborskii ◽  
P Availability ◽  
Chlorophyll A Concentration ◽  
Subtropical Lake ◽  
Total P

<p>Temporal variability in some water quality parameters can play an important role in determining the presence and abundance of primary producers, and consequently in the trophic state and other characteristics and uses of lake ecosystems. In this sense, the present study aimed at understanding temporal dynamics of some trophic relevant water quality parameters in different time scales and their correlation and influence in phytoplankton biomass (chlorophyll <em>a</em>) in a shallow subtropical coastal lake. Peri Lake is located in Florianópolis island in Southern Brazil and samples were taken monthly between March 2007 and February 2013. The lake showed low dissolved nutrients concentration, especially phosphorus (P) (median dissolved P: 2.0 µg.l<sup>-1</sup>)  and high chlorophyll <em>a</em> (median: 20.8 µg.l<sup>-1</sup>) concentration. Total nitrogen (TN) concentration varied broadly, with a median of 672.8 µg L<sup>-1</sup>, and total P (TP) concentration was low (median: 13.5 µg L<sup>-1</sup>). A seasonal pattern of variation concerning dissolved and total P and chlorophyll a concentration was observed, associated mainly with temperature and wind speeds, but no clear pattern was observed for nitrogen (N) fractions. Significant differences were observed in different years for some parameters, with higher chlorophyll a and lower N concentration in the last three years sampled. The lake was considered potentially P limited during the majority of the study period and a positive correlation was found between chlorophyll <em>a</em> and total and dissolved P concentration. Phytoplankton biomass (as chlorophyll <em>a</em>) was apparently controlled by water temperature and P availability (TN:TP ratio and dissolved P). Water transparency (as Secchi depth) was strongly and negatively influenced by chlorophyll <em>a</em> concentration. <em>Cylindrospermopsis raciborskii</em> abilities to compete for P and light seem to be important factors determining its success and dominance in this low P coastal ecosystem. The fluctuating P supply, probably associated to sediment resuspension by wind in this shallow waterbody, is an advantageous factor for cyanobacteria and has an important role in chlorophyll <em>a</em> dynamics. Thus, high chlorophyll <em>a</em> concentration in this subtropical lake seems to be related to the P-limited condition, shallowness and low water column transparency, which are probably favouring the dominance of <em>C. raciborskii</em>, especially in higher summer temperatures, and leading to high chlorophyll <em>a</em> concentration even in a low dissolved nutrient environment.</p>

scholarly journals Vertical distribution of chlorophyll <i>a</i> concentration and phytoplankton community composition from in situ fluorescence profiles: a first database for the global ocean

2015 ◽  
Vol 8 (1) ◽  
pp. 365-399
Author(s):  
R. Sauzède ◽  
H. Lavigne ◽  
H. Claustre ◽  
J. Uitz ◽  
C. Schmechtig ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Chlorophyll A ◽  
Community Composition ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
Environmental Data ◽  
Global Ocean ◽  
Control Procedure ◽  
Chlorophyll A Concentration ◽  
Phytoplankton Community Composition

Abstract. In vivo chlorophyll a fluorescence is a proxy of chlorophyll a concentration, and is one of the most frequently measured biogeochemical properties in the ocean. Thousands of profiles are available from historical databases and the integration of fluorescence sensors to autonomous platforms led to a significant increase of chlorophyll fluorescence profile acquisition. To our knowledge, this important source of environmental data has not yet been included in global analyses. A total of 268 127 chlorophyll fluorescence profiles from several databases as well as published and unpublished individual sources were compiled. Following a robust quality control procedure detailed in the present paper, about 49 000 chlorophyll fluorescence profiles were converted in phytoplankton biomass (i.e. chlorophyll a concentration) and size-based community composition (i.e. microphytoplankton, nanophytoplankton and picophytoplankton), using a~method specifically developed to harmonize fluorescence profiles from diverse sources. The data span over five decades from 1958 to 2015, including observations from all major oceanic basins and all seasons, and depths ranging from surface to a median maximum sampling depth of around 700 m. Global maps of chlorophyll a concentration and phytoplankton community composition are presented here for the first time. Monthly climatologies were computed for three of Longhurst's ecological provinces in order to exemplify the potential use of the data product. Original data sets (raw fluorescence profiles) as well as calibrated profiles of phytoplankton biomass and community composition are available in open access at PANGAEA, Data Publisher for Earth and Environmental Science. Raw fluorescence profiles: http://doi.pangaea.de/10.1594/PANGAEA.844485.

scholarly journals Enhanced chlorophyll-a concentration in the wake of Sable Island, eastern Canada, revealed by two decades of satellite observations: a response to grey seal population dynamics?

2021 ◽  
Author(s):  
Emmanuel Devred ◽  
Andrea Hilborn ◽  
Cornelia den Heyer
Keyword(s):  
Time Series ◽  
Chlorophyll A ◽  
Phytoplankton Biomass ◽  
Satellite Observations ◽  
Eastern Canada ◽  
Chlorophyll A Concentration ◽  
Chl A ◽  
Seal Population ◽  
Good Agreement

Abstract. Elevated surface chlorophyll-a concentration, an index of phytoplankton biomass, has been previously observed and documented by remote sensing in the waters to the southwest of Sable Island (SI) on the Scotian Shelf in eastern Canada. Here, we present a detailed analysis of this phenomenon using a 20-year time series of satellite-derived chlorophyll-a concentration (chl-a), paired with information on the particle backscattering coefficient at 443 nm (bbp(443)) and the detritus/gelbstoff absorption coefficient at 443 nm (adg(443) ) in an attempt to explain the possible mechanisms that lead to the increase in surface biomass in the surroundings of SI. We compared the seasonal cycle, climatology and trends of surface waters near SI to two control regions located both upstream and downstream of the island, away from terrigenous inputs. Application of the self-organizing maps approach (SOMs) to the time series of satellite-derived chl-a over the Scotian Shelf revealed the annual spatio-temporal patterns around SI and, in particular, persistently high phytoplankton biomass during winter and spring in the leeward side of SI, a phenomenon that is not observed in the control boxes. Time series analysis of the satellite archive evidenced a long-term increase in chl-a and adg(443), and a long-term decrease in bbp(443) in all regions. In the close vicinity of SI, the increase of chl-a and adg(443) during the winter months occurred at a rate twice that of the ones observed in the control boxes. In addition to the increase of the chl-a and adg(443) within the plume southward of SI, the surface area of the plume itself has also expanded by a factor of five over the last 20 years. While the island mass effect (IME) is certainly contributing to the enhanced biomass around SI, we hypothesize that the large increase in chl-a over the last 20 years is due to an injection of nutrients by the island’s grey seal colony, which has increased by about 300 % over the last twenty years. The contribution of nutrients from seals may sustain high phytoplankton biomass at a time of year when it is usually low. A conceptual model was developed to describe the annual variation of seal abundance on SI and estimate the standing stock of chl-a concentration that can be sustained by the release of nitrogen. Comparison between satellite observations and model simulations showed a very good agreement between the seal population increase on SI during the breeding season and the phytoplankton biomass increase during the winter. In addition, the 20-year satellite-derived trend in chlorophyll-a concentration showed a good agreement with the increasing trend in seal population on SI during the same time period. The satellite data analysis supports the concept of top-down control of marine mammals over lower trophic levels through a fertilisation mechanism, although these results could not be confirmed without in situ measurements for ground truthing. Our findings challenge the idea that the IME is restricted to islands with strong bathymetric slope located in oligotrophic waters of mid-latitudes and tropics, and demonstrate that enhanced marine production can occur in other oceanic regions, with potentially substantial implications for conservation and fisheries.

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