Evaluation of Factors Related to the Unusually Low Chlorophyll Levels in Prairie Saline Lakes

1986 ◽  
Vol 43 (4) ◽  
pp. 846-854 ◽  
Author(s):  
C. E. Campbell ◽  
E. E. Prepas

Prairie saline lakes in Canada have remarkably low chlorophyll a (Chl a) levels relative to total phosphorus (TP) and total nitrogen (TN) levels. To evaluate factors related to low Chl a levels, three Alberta saline lakes (total dissolved solids > 5 g∙L−1) were studied in 1983 and 1984. Mean summer phytoplankton Chl a ranged from 3 to 10 μg∙L−1, mean summer periphyton Chl a was less than 70 mg∙m−2, while mean summer TP and TN ranged from 2 to 13 and from 4 to 11 mg∙L−1, respectively. Chl a and phytoplankton primary production were extremely low relative to predictions from measured TP and TN levels and empirical models for freshwaters. Bioassays indicated that inorganic phosphorus was not limiting, whereas inorganic nitrogen was limiting algal growth. Bacterial densities and zooplankton dry weight were high (> 107 cells∙mL−1 and > 1.0 mg∙L−1, respectively) relative to predictions from Chl a and empirical models for freshwaters. Phytoplankton biomass was insufficient to maintain the zooplankton populations; bacteria and detritus were likely a major food source for zooplankton. This study suggests that freshwater models are not applicable to prairie saline lakes.

2020 ◽  
Vol 8 (9) ◽  
pp. 674 ◽  
Author(s):  
Ario Damar ◽  
Franciscus Colijn ◽  
Karl-Juergen Hesse ◽  
Luky Adrianto ◽  
Yonvitner ◽  
...  

A study of nutrients, underwater light dynamics, and their correlation with phytoplankton biomass was conducted in the tropical estuary of Jakarta Bay, Indonesia, in the dry season during the period from 2001 to 2019. This study analyzed the spatial and temporal dynamics of phytoplankton biomass and its correlation with phytoplankton biomass. There was significant increase in nutrient concentration in Jakarta Bay, with annual means of 27.97 µM dissolved inorganic nitrogen (DIN) and 11.31 µM phosphates in 2001, increasing to 88.99 µM DIN and 25.92 µM phosphates in 2019. Increased mean nutrient concentrations were accompanied by increased mean phytoplankton biomass, from 15.81 µg Chl-a L−1 in 2001 to 21.31 µg Chl-a L−1 in 2019. The eutrophication status of Jakarta Bay waters was calculated using the Tropical Index for Marine Systems eutrophication index, which showed increased areas of hyper-eutrophic and eutrophic zones, while the mesotrophic area decreased. The hyper-eutrophic zone dominated the areas around river mouths and the inner part of the bay, while eutrophic status was observed in the middle part of the bay and mesotrophic status was found in the outer part of the bay. The area of hyper-eutrophic water increased 1.5-fold, from 75.1 km2 in 2001 to 114.0 km2 in 2019. Increasing eutrophication of the bay has had negative ecological consequences including algal blooms, hypoxic conditions, and mass mortality of marine biota, and it urgently requires remediation.


2014 ◽  
Vol 65 (3) ◽  
pp. 191 ◽  
Author(s):  
Kwee Siong Tew ◽  
Pei-Jie Meng ◽  
David C. Glover ◽  
Jih-Terng Wang ◽  
Ming-Yih Leu ◽  
...  

Algal bloom is a major concern worldwide. In this study, we characterised the physical and biochemical parameters during an algal bloom event in a coastal lagoon in an attempt to predict local blooms in the future. Results showed that the highest concentrations of dissolved inorganic phosphorus (DIP), chlorophyll a (chl a) and phytoplankton abundance were found in the inner area, whereas the highest dissolved inorganic nitrogen (DIN) concentration occurred near the inlet-outlet channel. Chl a was correlated with DIP, and there was a significant exponential relationship between chl a and the nitrogen to phosphorus ratio (N/P ratio) across all sampling stations and times. A higher proportion of the variation in chl a was explained by the N/P ratio than either DIP or DIN. We found that a N/P ratio <2.38 will likely trigger an algal bloom (chl a ≥ 10 µgL–1) in the lagoon. Our results suggest that the N/P ratio could be used as an expedient and reliable measure of the potential eutrophic status of coastal lagoons.


2021 ◽  
Author(s):  
Marta F.-Pedrera Balsells ◽  
Manel Grifoll ◽  
Margarita Fernández-Tejedor ◽  
Manuel Espino ◽  
Marc Mestres ◽  
...  

Abstract. Phytoplankton primary production in coastal bays and estuaries is influenced by multiple physical variables, such as wind, tides, freshwater inputs or light availability. In a short-term perspective these factors may influence the composition of biological variables such as phytoplankton biomass, as well as the amount of nutrients within the waterbody. Observations in Fangar Bay, a small, shallow, stratified and micro-tidal bay in the Ebro Delta (NW Mediterranean Sea), have shown that during wind episodes the biological variables undergo sudden variations in terms of concentration and distribution within the bay. The Regional Ocean Model System (ROMS) coupled with a nitrogen-based nutrient, phytoplankton, zooplankton, and detritus (NPZD) model has been applied to understand this spatio-temporal variability of phytoplankton biomass in Fangar Bay. Idealised simulations prove that during weak wind events (< 6 m·s−1), the stratification is maintained and therefore there is not dynamic connection between surface and bottom layers, penalizing phytoplankton growth in the whole water column. Conversely, during intense wind events (> 10 m·s−1) water column mixing occurs, homogenising the concentration of nutrients throughout the column, and increasing phytoplankton biomass in the bottom layers. In addition, shifts in the wind direction generate different phytoplankton biomass distributions within the bay, in accordance with the dispersion of freshwater plumes from existing irrigation canals. Thus, the numerical results prove the influence of the freshwater plume evolution on the phytoplankton biomass distribution, which is consistent with remote sensing observations. The complexity of the wind-driven circulation due to the bathymetric characteristics and the modulation of the stratification implies that the phytoplankton biomass differs depending on the prevailing wind direction, leading to sharp Chl a gradients and complex patterns.


2014 ◽  
Vol 42 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Md Almujaddade Alfasane ◽  
Md Sharif Ullah ◽  
Moniruzzaman Khondker

In lake Rainkhyongkain, water temperature, pH, conductivity and total dissolved solids (TDS) were recorded 33.5°C, 7.39, 308 ?S/cm and 49 mg/l, respectively. The mean values (n = 4) of dissolved oxygen content (DO), alkalinity, soluble reactive phosphorus (SRP), soluble reactive silicate (SRS) and NO3-N were 7.93 ± 0.78 mg/l, 1.70 ± 0.12 meq/l, 17.25 ± 0.62 ?g/l, 10.44 ± 0.72 mg/l and 34.00 ± 4.00 ?g/l, respectively. The phytoplankton biomass as chlorophyll a (chl a) was found very low (4.93 ± 0.51 ?g/l) with a phaeopigment concentration of 1.97 ± 0.51 ?g/l. A total of 16 phytoplankton taxa were recorded of which Cyclotella comensis (V. Keissler) Lemm. was dominant followed by Protoperidinium conicum (Gran) Balech, Coelosphaerium kuetzingianum Näg., Euglena spp. and Mallomonas paxillata Bardley. For the first time in Bangladesh Marchantia polymorpha L. var. aquatica Nees was found to grow in masses in the shallow littoral of the lake. Among the dominant macrophytes of the littoral, Nymphaea stellata Willd., Nymphoides indicum (L.) O. Kuntze and Monochoria hastata (L.) Solms were common. DOI: http://dx.doi.org/10.3329/bjb.v42i2.18023 Bangladesh J. Bot. 42(2): 223-229, 2013 (December)


2018 ◽  
Author(s):  
Widya Ratmaya ◽  
Dominique Soudant ◽  
Jordy Salmon-Monviola ◽  
Nathalie Cochennec-Laureau ◽  
Evelyne Goubert ◽  
...  

Abstract. The evolution of eutrophication (i.e., phytoplankton biomass) during recent decades was examined in the coastal waters of Vilaine Bay (VB, France) in relation to those in their main external nutrient sources, the Loire and Vilaine Rivers. Dynamic Linear Models, corroborated by the Mann-Kendall test, were used to study long-term trends and seasonality of dissolved inorganic nutrient and chlorophyll a concentrations (Chl a) in rivers and coastal waters between 1980 and 2013. The reduction in dissolved riverine inorganic phosphorus concentrations (DIP) from the early 1990s led to the decrease in their Chl a levels. However, dissolved inorganic nitrogen concentrations (DIN) decreased only slightly in the Vilaine and actually increased in the Loire, especially during summer. Simultaneously, phytoplankton in the VB has undergone profound changes with: (1) increase in biomass, (2) change in the position of the annual peak from spring to summer, and (3) increase in diatom:dinoflagellate ratios, especially in summer. The increase in phytoplankton biomass in VB, particularly in summer, was probably due to increased DIN loads from the Loire, sustained by internal regeneration of DIP and dissolved silicate from sediments. This long-term ecosystem-scale analysis reports the consequence of nutrient management scenarios focused solely on P reduction. Freshwater ecosystems upstream reveal successful recoveries through the control of P alone, while eutrophication continues to increase downstream, especially during the period of N limitation. Therefore, nutrient management strategies, paying particular attention to diffuse N-sources, are required to control eutrophication in receiving coastal waters.


2015 ◽  
Vol 63 (4) ◽  
pp. 443-454 ◽  
Author(s):  
Marina Cavalcanti Jales ◽  
Fernando Antônio do Nascimento Feitosa ◽  
Maria Luise Koening ◽  
Manuel de Jesus Flores Montes ◽  
Moacyr Cunha de Araújo Filho ◽  
...  

Abstract The Rocas Atoll Biological Reserve is located in the Atlantic Ocean, at 3º 51' S and 33º 49' W. It lies 143 nautical miles from the City of Natal, Rio Grande do Norte (Brazil). The purpose of this study was to analyze the hydrology, water masses, currents and chlorophyll a content to determine the dynamics of phytoplankton biomass around the Rocas Atoll. Samples were collected in July 2010 in the area around the Atoll, using the Research Vessel Cruzeiro do Sul of the Brazilian Navy. Two transects were established according to the surface currents, one of which at the southeast of the Atoll (SE) and the other at norwest (NW). Three collection points were determined on each of these transects. Samples were collected at different depths (surface and DCM - Deep Chlorophyll Maximum) and different times (day and night). According to PCA (Principal Component Analysis), the nutrients analyzed, DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus) and silicate, were inversely correlated with temperature and dissolved oxygen. Most environmental variables showed a significant increase due to the turbulence on the Northwest transect. There was an increase in the concentration of chlorophyll a and nutrients when the temperature and oxygen in the mixed layer was reduced due to the influence of the SACW (South Atlantic Central Water). Despite the increase observed in some variables such as nutrient salts and chlorophyll a, the temperature in the mixed layer attained a mean value of 23.23 ºC due to the predominance of Tropical Water. The increase of the phytoplankton biomass on the NW transect was, therefore, caused by the "island effect" and not by upwelling.


1985 ◽  
Vol 42 (10) ◽  
pp. 1588-1594 ◽  
Author(s):  
J. F. H. Bierhuizen ◽  
E. E. Prepas

We collected data from 20 saline lakes (total dissolved solids from 1000 to 91 000 mg∙L−1) in southeastern Alberta to compare relationships between phosphorus, nitrogen, and phytoplankton standing crop with those in freshwater lakes. In 18 lakes, Na+, Mg2+, SO42−, and HCO3−-CO32− were the dominant ions. In these lakes there was a significant positive correlation between Ca2+ and chlorophyll a (Chl a), and there were significant negative correlations between Chl a and conductivity, pH, Na+, Mg2+, SO42−, HCO3−, and CO32−. When all 20 lakes were considered there were no significant relationships between Chl a and phosphorus or nitrogen. Empirical relationships for freshwater lakes, based on spring or summer total phosphorus (TP) or total nitrogen (TN), overestimated Chl a in all the study lakes. However, in saline lakes with similar ionic composition and TN to TP ratios greater than 12 (by weight), there was a significant positive relationship between TP and Chl a. For the saline lakes with TN to TP ratios greater than 12, the deviations between the Chl a levels predicted from models developed for freshwater lakes and the observed levels were positively correlated with conductivity, total dissolved solids, and Na+ (r2 = 0.78–0.82, P < 0.001). We developed the first empirical model that describes nutrient – Chl a relationships for inland saline lakes. The deviation of measured phytoplankton biomass from that predicted by models developed for freshwater lakes can be explained by conductivity or dominant ion concentration.


2019 ◽  
Vol 16 (6) ◽  
pp. 1361-1380 ◽  
Author(s):  
Widya Ratmaya ◽  
Dominique Soudant ◽  
Jordy Salmon-Monviola ◽  
Martin Plus ◽  
Nathalie Cochennec-Laureau ◽  
...  

Abstract. The evolution of eutrophication parameters (i.e., nutrients and phytoplankton biomass) during recent decades was examined in coastal waters of the Vilaine Bay (VB, France) in relation to changes in the Loire and Vilaine rivers. Dynamic linear models were used to study long-term trends and seasonality of dissolved inorganic nutrient and chlorophyll a concentrations (Chl a) in rivers and coastal waters. For the period 1997–2013, the reduction in dissolved riverine inorganic phosphorus (DIP) concentrations led to the decrease in their Chl a levels. However, while dissolved inorganic nitrogen (DIN) concentrations decreased only slightly in the Vilaine, they increased in the Loire, specifically in summer. Simultaneously, phytoplankton in the VB underwent profound changes with increase in biomass and change in the timing of the annual peak from spring to summer. The increase in phytoplankton biomass in the VB, manifested particularly by increased summer diatom abundances, was due to enhanced summer DIN loads from the Loire, sustained by internal regeneration of DIP and dissolved silicate (DSi) from sediments. The long-term trajectories of this case study evidence that significant reduction of P inputs without simultaneous N abatement was not yet sufficient to control eutrophication all along the Loire–Vilaine–VB continuum. Upstream rivers reveal indices of recoveries following the significant diminution of P, while eutrophication continues to increase downstream, especially when N is the limiting factor. More N input reduction, paying particular attention to diffuse N sources, is required to control eutrophication in receiving VB coastal waters. Internal benthic DIP and DSi recycling appears to have contributed to the worsening of summer VB water quality, augmenting the effects of anthropogenic DIN inputs. For this coastal ecosystem, nutrient management strategies should consider the role played by internal nutrient loads to tackle eutrophication processes.


2013 ◽  
Vol 64 (10) ◽  
pp. 938 ◽  
Author(s):  
N. K. Carrasco ◽  
R. Perissinotto ◽  
A. Whitehead

The encroachment of agriculture and human population is placing increasing levels of stress on estuarine ecosystems worldwide. The catchment of the Seteni Estuary, a small temporarily open/closed estuary in South Africa, has been under extensive sugar cultivation for over 60 years. The present study reports on the impact of agricultural practices on the structure and dynamics of its pelagic communities over a 1-year period, from April 2008 to March 2009. The physico-chemical characteristics of the system were strongly linked to seasonality, with the system exhibiting a distinct open- and closed-mouth phase in response to rainfall. Concentrations of dissolved inorganic nitrogen (DIN) were exceptionally high in comparison to concentrations of dissolved inorganic phosphorus (DIP), resulting in high DIN : DIP ratios. Despite this, microalgal biomass remained relatively low, exhibiting maximum values of 91.7 mg chl a m–2 and 18.0 mg chl a m–3 for microphytobenthos and phytoplankton, respectively. Zooplankton abundance and biomass were significantly higher during the dry phase, with Pseudodiaptomus hessei dominating the zooplankton community both in terms of abundance and biomass throughout the study period. The ichthyofaunal community was dominated by Ambassis ambassis and Myxus capensis in terms of abundance and biomass, respectively. Results suggest that the system remains functional, but there is potential for deterioration, should the catchment become more nutrient-rich through poor management or land-use changes.


2015 ◽  
Vol 36 (2) ◽  
pp. 37-49
Author(s):  
M.S. Nugrahadi

Brantas River basin and Madura Strait in East Java Indonesia, are subject to heavily change in land use and land cover, and Brantas River Basin is a very important densely populated area in East Java, Indonesia for agriculture, industry as well as for settlement. The aim of the research is to elucidate the fate of transformation of bio-elements (organic carbon, Nitrogen (N), Phosphorus (P), and Silicate (Si)) and its seasonal variability. The contrast river discharge combined with tide generates the distinctive mixing zone during rainy and dry season. Dissolved Inorganic Nitrogen (DIN) and Dissolved Inorganic Phosphorus (DIP) concentrations in the river are high and decrease to the very low value seaward. N:P ratio has seasonal variation due to large discrepancy of DIN and DIP supply from land to the sea. Dissolved Inorganic Silicate (DSi) in river and estuaries is extremely higher than the average in the world (> 150 mM). Chlorophyll-a (Chl-a) in dry season in the coastal water is higher than the rainy season. Due to high Total Suspended Matter (TSM), the primary production is limited by the light in the coastal water.


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