Assessment of ammonia toxicity in tests with the microalga, Nephroselmis pyriformis, Chlorophyta

Källqvist, Torsten; Svenson, Anders

doi:10.1016/s0043-1354(02)00361-5

Cited by 153 publications

(62 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4). This is at the lower end of reported ammonium concentrations with inhibitory effects on algal growth, and insensitivity to much higher concentrations (up to 440 µmol L −1 ) of marine algal species have also been found (Thomas et al, 1980;Bates et al, 1993;Kallqvist and Svenson, 2003). Nevertheless, a combined effect of hypoxia and ammonium inhibition remains a possibility and, since they are correlated, could reinforce each other.…”

Section: Figmentioning

confidence: 75%

“…In such a reduced environment (Billen et al, 1988), benthic and pelagic sulfide production might have toxic effects on phytoplankton. And also elevated ammonium concentrations are known to be harmful to algae (Thomas et al, 1980;Bates et al, 1993;Kallqvist and Svenson, 2003). Therefore we hypothesize that algal growth was inhibited as a result of high organic waste and ammonia loading, leading to elevated ammonium concentrations, oxygen depletion and a strongly reduced environment.…”

Section: Water Quality In the Fw Schelde From The 1960s To Presentmentioning

confidence: 95%

See 1 more Smart Citation

A macro-tidal freshwater ecosystem recovering from hypereutrophication: the Schelde case study

et al. 2009

View full text Add to dashboard Cite

Abstract. We report a 40 year record of eutrophication and hypoxia on an estuarine ecosystem and its recovery from hypereutrophication. After decades of high inorganic nutrient concentrations and recurring anoxia and hypoxia, we observe a paradoxical increase in chlorophyll-a concentrations with decreasing nutrient inputs. We hypothesise that algal growth was inhibited due to hypereutrophication, either by elevated ammonium concentrations, severe hypoxia or the production of harmful substances in such a reduced environment. We study the dynamics of a simple but realistic mathematical model, incorporating the assumption of algal growth inhibition. It shows a high algal biomass, net oxygen production equilibrium with low ammonia inputs, and a low algal biomass, net oxygen consumption equilibrium with high ammonia inputs. At intermediate ammonia inputs it displays two alternative stable states. Although not intentional, the numerical output of this model corresponds to observations, giving extra support for assumption of algal growth inhibition. Due to potential algal growth inhibition, the recovery of hypereutrophied systems towards a classical eutrophied state, will need reduction of waste loads below certain thresholds and will be accompanied by large fluctuations in oxygen concentrations. We conclude that also flow-through systems, heavily influenced by external forcings which partly mask internal system dynamics, can display multiple stable states.

show abstract

Section: Figmentioning

confidence: 75%

Section: Water Quality In the Fw Schelde From The 1960s To Presentmentioning

confidence: 95%

A macro-tidal freshwater ecosystem recovering from hypereutrophication: the Schelde case study

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Samples for nutrient analysis were filtered through 0.7 µm pore size GF/F filters prior to analysis. No effort was made in the present study to separate the concentration of NH 4 + from that of un-ionized ammonia (NH 3 ), which is toxic at relatively low concentrations (Källqvist & Svenson 2003). The concentration of ammonia as a fraction of the total ammonia pool (NH 4 + +NH 3 ) is typically below 1% at pH 7 and below 2% at pH 8 (Collos & Harrison 2014), therefore of minor concern in the present investigation.…”

Section: Methodsmentioning

confidence: 89%

Impact of atypical ammonium concentrations on phytoplankton abundance and composition in fresh versus estuarine waters

Esparza¹,

Farrell²,

Craig³

et al. 2014

Aquat. Biol.

View full text Add to dashboard Cite

“…Toxicity of NH 4 + ions were found to be 100 times less toxic than neutral NH 3 to microalga, Nephroselmis pyriformis, as determined by comparing EC50 levels required to elicit toxicity responses (Källqvist and Svenson, 2003). Ammonia toxicity has been associated with reduced tissue respiration of roots, perhaps due to disruption of membrane integrity (Vines and Wedding, 1960).…”

Section: Core Ideasmentioning

confidence: 99%

Ammonia/Ammonium Toxicity Root Symptoms Induced by Inorganic and Organic Fertilizers and Placement

et al. 2016

View full text Add to dashboard Cite

Ammoniacal fertilizers can cause seedling damage. The present aims were to characterize spatial and temporal, root morphological NH3/NH4+ toxicity symptoms, assess the extent of the toxicity zone, and relate species‐specific responses to their root architecture. Wheat (Triticum aestivum L.) and canola (Brassica napus L.) were exposed to seed and deep placed urea. Faba (Vicia faba L) seedlings were grown above organic amendments. Time‐sequential images of canola root apex and root hair die‐back, discoloration, and accelerated lateral rooting were captured with soil‐buried, high resolution digital scanners. Seed‐placed urea stunted wheat shoot and root radicles, while slow‐release urea reduced these symptoms. Primary axes of all three species were damaged by encountering the deep fertilizer zones. The multiple seminal axes and lateral root growth away from the fertilizer allowed greater wheat seedling survival, while toxicity‐damage to a single tap root of the germinating canola and faba often resulted in seedling mortality. Urea and chicken manure developed expanded NH3/NH4+ toxicity zones 1.5 to 5 cm, eliciting similar toxicity symptoms initiated at the root apex. Within 3 d after planting, canola tap root elongation stopped, followed by progressive basal directed necrosis and shrinking of the root axis, root hairs. These characteristic symptoms may be used for future toxicity diagnostics of soil‐grown plants. Elevated pH in the soil zone above the chicken manure suggested NH3 gas transported through soil pores followed by H+ consumption and elevated NH4+. Ammonia gas toxicity and species‐specific root system architecture should be considered in N placement and source selection.Core Ideas NH3/NH4+ toxicity initiates at the root apex and moves basipetally. Symptoms include tissue discoloration, axis shrinkage, root hair disfigurement, and seedling death. Toxicity zones ranged from 1 to 5 cm from the ammonia sources. Putative upward movement of ammonia raised soil pH and NH4+ above chicken manure. Most wheat axes avoided NH3/NH4+ toxicity zones, improving survival over tap‐rooted species.

show abstract

Assessment of ammonia toxicity in tests with the microalga, Nephroselmis pyriformis, Chlorophyta

Cited by 153 publications

References 12 publications

A macro-tidal freshwater ecosystem recovering from hypereutrophication: the Schelde case study

A macro-tidal freshwater ecosystem recovering from hypereutrophication: the Schelde case study

Impact of atypical ammonium concentrations on phytoplankton abundance and composition in fresh versus estuarine waters

Ammonia/Ammonium Toxicity Root Symptoms Induced by Inorganic and Organic Fertilizers and Placement

Contact Info

Product

Resources

About