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

Elem Sci Anth ◽  
2018 ◽  
Vol 6 ◽  
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.

scholarly journals Patterns in nutrient limitation and chlorophyll a along an anthropogenic eutrophication gradient in French Mediterranean coastal lagoons

2010 ◽  
Vol 67 (4) ◽  
pp. 743-753 ◽  
Author(s):  
Philippe Souchu ◽  
Béatrice Bec ◽  
Val H. Smith ◽  
Thierry Laugier ◽  
Annie Fiandrino ◽  
...  
Keyword(s):  
Nutrient Limitation ◽  
Chlorophyll A ◽  
Nutrient Enrichment ◽  
Coastal Waters ◽  
Coastal Lagoons ◽  
Inorganic Nitrogen ◽  
Nutrient Concentrations ◽  
Chl A ◽  
Mediterranean Lagoons ◽  
Ecosystem Comparison

A cross-ecosystem comparison of data obtained from 20 French Mediterranean lagoons with contrasting eutrophication status provided the basis for investigating the variables that best predict chlorophyll a (Chl a) concentrations and nutrient limitation of phytoplankton biomass along a strong nutrient enrichment gradient. Summer concentrations of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) comprised only a small fraction of total nitrogen (TN) and total phosphorus (TP). On the basis of inorganic nutrient concentrations, the most oligotrophic lagoons appeared to be phosphorus-limited, with a tendency towards the development of nitrogen limitation as eutrophication increased, as evidenced by decreasing DIN:DIP ratios. A weak but significantly positive relationship was found between dissolved silicate (DSi) and Chl a, reflecting DSi accumulation in the water column along the trophic state gradient and implying a progressive shift away from potential Si limitation of phytoplankton growth. Observed concentrations of Chl a were far better explained by TN and TP than by DIN and DIP concentrations, suggesting that a total nutrient based approach is likely to be the most appropriate for managing eutrophication in Mediterranean lagoons and other coastal waters. These results give credence to the idea that marine and freshwater environments respond in a similar fashion to nutrient enrichment.

Linkage between Epilithic Algal Growth and Water Column Nutrients in Softwater Lakes

1992 ◽  
Vol 49 (8) ◽  
pp. 1641-1649 ◽  
Author(s):  
G. Winfield Fairchild ◽  
John W. Sherman
Keyword(s):  
Nutrient Limitation ◽  
Water Column ◽  
Chlorophyll A ◽  
Standing Crop ◽  
Crop Production ◽  
Dissolved Inorganic Carbon ◽  
Inorganic Nitrogen ◽  
Algal Growth ◽  
Acidic Lakes ◽  
Softwater Lakes

We examined the dependence of epilithic algal standing crop, production, and nutrient limitation upon water column nutrients in 12 softwater lakes of northeastern Pennsylvania. Elevated dissolved inorganic nitrogen accompanied low dissolved inorganic carbon in the more acidic lakes, while P varied little within the study area. The growth of epilithon on clay flower pot substrata diffusing combinations of N (NaNO3), P (Na2HPO4), and C (NaHCO3) was compared with growth on control substrata to evaluate which of the three nutrients limited growth in each lake. Standing crop accrual as chlorophyll a on control substrata averaged 0.8 μg/cm2, with little variation among lakes. Nutrient limitation of growth, however, was strongly related to lake alkalinity. Chlorophyll a was typically enhanced by N and/or P only in lakes with alkalinity greater than ~100 μeq/L and responded strongly to C enrichment in the two most acidic lakes. Combined addition of all three nutrients produced the largest chlorophyll a accrual in all 12 lakes. Invertebrate grazer biomass, dominated by chironomids in the more acidic lakes and by snails at higher alkalinity, was negatively related to chlorophyll a on these NPC substrata (r = −0.57, p = 0.05) and may have reduced algal standing crop well below nutrient-sustainable levels in some lakes.

scholarly journals Short-Term Response of Chlorophyll a Concentration Due to Intense Wind and Freshwater Peak Episodes in Estuaries: The Case of Fangar Bay (Ebro Delta)

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 701
Author(s):  
Marta F-Pedrera Balsells ◽  
Manel Grifoll ◽  
Margarita Fernández-Tejedor ◽  
Manuel Espino
Keyword(s):  
Water Column ◽  
Chlorophyll A ◽  
Temporal Variability ◽  
Ebro Delta ◽  
Small Scale ◽  
Local Wind ◽  
Short Term ◽  
Chlorophyll A Concentration ◽  
Chl A ◽  
Coastal Bays

Estuaries and coastal bays are areas of large spatio-temporal variability in physical and biological variables due to environmental factors such as local wind, light availability, freshwater inputs or tides. This study focuses on the effect of strong wind events and freshwater peaks on short-term chlorophyll a (Chl a) concentration distribution in the small-scale and microtidal, Fangar Bay (Ebro Delta, northwestern Mediterranean). The hydrodynamics of this bay are primarily driven by local wind episodes modulated by stratification in the water column. Results based on field-campaign observations and Sentinel-2 images revealed that intense wind episodes from both NW (offshore) and NE-E (onshore) caused an increase in the concentration of surface Chl a. The mechanisms responsible were horizontal mixing and the bottom resuspension (also linked to the breakage of the stratification) that presumably resuspended Chl a containing biomass (i.e., micropyhtobentos) and/or incorporated nutrients into the water column. On the other hand, sea-breeze was not capable of breaking up the stratification, so the chlorophyll a concentration did not change significantly during these episodes. It was concluded that the mixing produced by the strong winds favoured an accumulation of Chl a concentration, while the stratification that causes a positive estuarine circulation reduced this accumulation. However, the spatial-temporal variability of the Chl a concentration in small-scale estuaries and coastal bays is quite complex due to the many factors involved and deserve further intensive field campaigns and additional numerical modelling efforts.

scholarly journals Impact of an anticyclonic eddy on the summer nutrient and chlorophyll a distributions in the Ulleung Basin, East Sea (Japan Sea)

2011 ◽  
Vol 69 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Dongseon Kim ◽  
Eun Jin Yang ◽  
Kyung Hee Kim ◽  
Chang-Woong Shin ◽  
Jisoo Park ◽  
...  
Keyword(s):  
Water Column ◽  
Chlorophyll A ◽  
Surface Waters ◽  
Japan Sea ◽  
Anticyclonic Eddy ◽  
East Sea ◽  
Ulleung Basin ◽  
Surface Mixed Layer ◽  
High Concentration ◽  
Chl A

Abstract Kim, D., Yang, E. J., Kim, K. H., Shin, C-W., Park, J., Yoo, S., and Hyun, J-H. 2012. Impact of an anticyclonic eddy on the summer nutrient and chlorophyll a distributions in the Ulleung Basin, East Sea (Japan Sea). – ICES Journal of Marine Science, 69: 23–29. The impact of the anticyclonic Ulleung Warm Eddy (UWE) on the vertical distributions of nutrient and chlorophyll a (Chl a) concentrations in the Ulleung Basin (UB) was investigated during the contrasting summers of 2005 and 2007. The physical structure of the water column was characterized by an intrathermocline eddy (ITE) in 2005, whereas the UWE remained distant from the sampling transect in 2007. Water column structures appeared to be highly stratified, and nutrients in the surface waters were totally depleted at all stations. In 2005, an exceptionally high concentration of Chl a (5.5 mg m−3) was measured below the surface mixed layer in the eddy core (station D3), and values of ∼2.5 mg m–3 were observed at the eddy edge (stations D2 and D4). Formation of an ITE efficiently mixed surface and deep-ocean waters, the latter supplying sufficient nutrients to generate an extremely high concentration of Chl a at the base of the subsurface layer. Overall, the results indicated that the anticyclonic UWE plays a key ecological role in supporting substantial phytoplankton biomass in the nutrient-depleted surface waters in summer and maintaining high benthic mineralization in the deep-sea sediments of the UB.

Nutrient uptake, chlorophyll a and carbon fixation by Rhodomonas sp. (Cryptophyceae) cultured at different irradiance and nutrient concentrations

2006 ◽  
Vol 35 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Fabiola Lafarga-De la Cruz ◽  
Enrique Valenzuela-Espinoza ◽  
Roberto Millán-Núñez ◽  
Charles C. Trees ◽  
Eduardo Santamaría-del-Ángel ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Chlorophyll A ◽  
Carbon Fixation ◽  
Nutrient Concentrations

scholarly journals Response of chlorophyll a to total nitrogen and total phosphorus concentrations in lotic ecosystems: a systematic review

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Micah G. Bennett ◽  
Sylvia S. Lee ◽  
Kate A. Schofield ◽  
Caroline E. Ridley ◽  
Benjamin J. Washington ◽  
...  
Keyword(s):  
Systematic Review ◽  
Water Column ◽  
Total Nitrogen ◽  
Effect Size ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Effect Sizes ◽  
Nutrient Concentrations ◽  
Lotic Ecosystems ◽  
Chl A

Abstract Background Eutrophication of freshwater ecosystems resulting from nitrogen and phosphorus pollution is a major environmental stressor across the globe. In this systematic review, we compiled and synthesized literature on sestonic and benthic chlorophyll a (chl-a) responses to total nitrogen (TN) and total phosphorus (TP) concentrations in the water column in streams and rivers to provide a state-of-the-science summary of nutrient impacts on these endpoints. This review was motivated by the need for comprehensive information on stressor-response relationships for the most common nutrient and biotic response measures used by state-level environmental managers in the United States to assess eutrophication of lotic ecosystems and support environmental decision making. Methods Searches for peer-reviewed and non-peer-reviewed articles were conducted using bibliographic databases, specialist websites, and search engines. These returns were supplemented with citation mapping and requests for material from experts. Articles were screened for relevance using pre-determined eligibility criteria, and risk of bias was evaluated for each included article based on study type-specific criteria. Narrative summaries and meta-analysis were used to evaluate four primary stressor-response relationships: TN-benthic chl-a, TP-benthic chl-a, TN-sestonic chl-a, and TP-sestonic chl-a. Potential effects of modifying factors and study validity on review conclusions were assessed via sensitivity and sub-group analysis and meta-regression. Results Meta-analysis of 105 articles, representing 439 cause-effect pairs, showed that mean effect sizes of both benthic and sestonic chl-a responses to TN and TP were positive. Of the four stressor-response relationships examined, TP-sestonic chl-a had the most positive relationship, followed by TN-benthic chl-a, TN-sestonic chl-a, and TP-benthic chl-a. For individual U.S. states, mean effect sizes for the four stressor-response relationships were mostly positive, with a few exceptions. Chlorophyll measurement method had a moderately significant influence on mean effect size for TP-sestonic chl-a, with chl-a responding more strongly to TP if fluorometry versus spectrophotometry was used. Year of publication had a significant negative effect on mean effect size, as did mean nutrient concentration for both sestonic chl-a nutrient relationships. When the same study measured both TN and TP, chl-a tended to respond similarly to both nutrients. Sensitivity analysis indicated that conclusions are robust to studies with high risk of bias. Conclusions This systematic review confirms that nutrients consistently impact primary producer biomass in streams and rivers worldwide. It builds on previous literature syntheses evaluating chl-a responses to nutrient concentrations and confirms that benthic and sestonic chl-a respond positively to nutrients across a range of stream and river conditions, but also points to limits on these relationships (e.g., potential saturation at high nutrient concentrations). Lack of consistent reporting of contextual data limited our ability to examine how moderating factors influenced these stressor-response relationships. Overall, we provide nutrient managers responsible for protecting the quality of lotic ecosystems with a comprehensive evidence base for chl-a responses to TN and TP concentrations in the water column.

scholarly journals Short-term variability and transport of nutrients and Chlorophyll-a in Bertioga Channel, São Paulo State, Brazil

2005 ◽  
Vol 53 (3-4) ◽  
pp. 99-114 ◽  
Author(s):  
Sônia Maria Flores Gianesella ◽  
Flávia Marisa Prado Saldanha-Corrêa ◽  
Luiz Bruner de Miranda ◽  
Marco Antonio Corrêa ◽  
Gleyci Aparecida Oliveira Moser
Keyword(s):  
Chlorophyll A ◽  
Neap Tide ◽  
Inorganic Nitrogen ◽  
Spring Tide ◽  
Southeastern Brazil ◽  
Nutrient Concentrations ◽  
P Availability ◽  
Short Term ◽  
Chl A ◽  
Short Term Variability

Short-term variability of nutrients, chlorophyll-a (Chl-a) and seston (TSS) concentrations were followed up at a fixed station in the Bertioga Channel (BC), Southeastern Brazil, over two full tidal cycles of neap and spring tides, during the winter of 1991. Simultaneous data on hydrographic structure, tidal level and currents allowed the computation of the net transport of those properties. Tidal advection and freshwater flow were the main forcing agents on the water column structure, nutrient availability and Chl-a distribution. Dissolved inorganic nitrogen and phosphate average values were high (16.88 and 0.98 ¼M, respectively, at neap tide and 10.18 and 0.77¼M at spring tide). Despite N and P availability, Chl-a average values were low: 1.13 in the neap and 3.11 mg m-3 in the spring tide, suggesting that the renovation rate of BC waters limits phytoplankton accumulation inside the estuary. The highest Chl-a was associated with the entrance of saltier waters, while the high nutrient concentrations were associated with brackish waters. Nutrients were exported on both tides, TSS and Chl-a were exported on the spring tide and Chl-a was imported on the neap tide. The study of the main transport components indicated that this system is susceptible to the occasional introduction of pollutants from the coastal area, thus presenting a facet of potential fragility.

Unifying Nutrient–Chlorophyll Relationships in Lakes

1989 ◽  
Vol 46 (7) ◽  
pp. 1176-1182 ◽  
Author(s):  
Yves T. Prairie ◽  
Carlos M. Duarte ◽  
Jacob Kalff
Keyword(s):  
Nutrient Limitation ◽  
Chlorophyll A ◽  
Nutrient Concentrations ◽  
Regression Equations ◽  
Independent Data ◽  
Nitrogen And Phosphorus ◽  
Nutrient Levels ◽  
Tn:Tp Ratio ◽  
Over Time

We used data drawn from the literature to test some basic predictions derived from nutrient limitation theory. Contrary to expectation, nitrogen was not better correlated to chlorophyll in nitrogen limited lakes (as measured by the total nitrogen:total phosphorus (TN:TP) ratio). We also examined whether the variability in published relationships between chlorophyll a (Chla) and nutrient levels in lakes can be explained by differences in the relative concentrations of nitrogen and phosphorus (TN:TP ratio). Our results show that the coefficients and precision of the Chla = f(TP) and Chla = f(TN) regression equations vary systematically and concomitantly with TN:TP ratios, and are highest for lakes with TN:TP ratios of 23–28 (by weight). These findings were confirmed with independent data and explain the variability of published Chla = f(TP) relationships. We propose a model that predicts the coefficients of Chla = f(TP) and Chla = f(TN) equations for lakes with different TN:TP ratios. This model proved useful in predicting the chlorophyll trajectories of lakes over time. The results imply an "optimal" TN:TP ratio beyond which the relative rates of increase in chlorophyll with increasing nutrient concentrations are reduced.

Dynamics of annual nutrinets and bloom-forming cyanobacteria, revealed by daily observation in a hyper-eutrophic lake

2020 ◽  
Author(s):  
Mengyuan Zhu ◽  
Guangwei Zhu ◽  
Hans Paerl ◽  
Wei Zhang ◽  
Hai Xu
Keyword(s):  
Water Column ◽  
Phytoplankton Biomass ◽  
Lake Taihu ◽  
Eutrophic Lake ◽  
Trophic Levels ◽  
Monitoring Data ◽  
Limiting Factors ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Chl A

<p>Daily monitoring over a period of one year in Lake Taihu, China, included chlorophyll a (Chl-a) and nutrient measurements, determining the taxonomic composition of the phytoplankton community and various water column physicochemical parameters. Chl-a and nutrient concentrations showed strong circadian variations ‒ Chl-a rised during daylight hours, while ammonium and phosphate rised at night. Chl-a concentrations also showed strong seasonal variations, with one annual peak in spring and another from summer to autumn, dominated by Dolichospermum spp. and Microcystis spp. respectively. Temperature appeared to exert the most important effect in this species succession. A nutrient‒Chl-a balance calculation indicated that both nitrogen and phosphorus in the water column could be limiting factors for phytoplankton growth during bloom periods. Over two thirds of particulate nutrients was attributed to phytoplankton biomass during blooms. Daily (or weekly) monitoring data provided more precise description of water quality, capturing short-term peaks in phytoplankton biomass, and reduced risks of under- or overestimating trophic levels in lakes, which always happened when using monthly monitoring data.</p>

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