Effects of filtration timing and pore size on measured nutrient concentrations in environmental water samples

Reed, Megan H.; Strope, Erica K.; Cremona, Fabien; Myers, Justin A.; Newell, Silvia E.; McCarthy, Mark J.

doi:10.1002/lom3.10529

Cited by 6 publications

(2 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous ecological models 18,19 and conceptual considerations 4 have proposed stoichiometric limits to phytoplankton N and P cell contents depending on relative water N and P concentrations, with accumulation of reactive nutrients when these are available in excess. Based on this, we hypothesise high TP model slopes, high R², and low concentrations of reactive pelagic P in the form of soluble reactive phosphorus (SRP) at higher TN : TP, and high TN model slopes, high R² and low concentrations of reactive pelagic N as nitrate-N at lower TN : TP (d).Ammonium-N most energetically favorable inorganic N form for algal growth 20,21 , but concentration measurements are scarce and unreliable due to its bioreactivity 22 . We chose nitrate-N, as it is less energetically favorable, and thus more prone to accumulate at measurable concentrations, and more likely to accumulate over long-term periods 23,24 .…”

Section: Mainmentioning

confidence: 99%

Consistent stoichiometric long-term relationships between nutrients and chlorophyll-a across lakes

Graeber,

McCarthy,

Shatwell

et al. 2023

Preprint

View full text Add to dashboard Cite

Aquatic ecosystems are threatened by eutrophication from nutrient pollution1. In lakes, eutrophication causes a plethora of deleterious effects, such as harmful algal blooms, fish kills2 and increased methane emissions3. However, lake-specific responses to nutrient changes are highly variable, complicating eutrophication management4. These lake-specific responses could result from short-term stochastic drivers overshadowing lake-independent, long-term relationships between phytoplankton and nutrients5. Here we show that strong stoichiometric relationships exist between nutrients and chlorophyll a (Chla) for 5-year simple moving averages (SMAs, median R² = 0.87) along a gradient of total nitrogen to total phosphorus (TN : TP) ratios. These stoichiometric relationships are consistent across 159 shallow lakes from a cross-continental, open-access database. We calculated 5-year SMA residuals to assess short-term variability and found substantial short-term Chla variation which was weakly related to nutrient concentrations (median R² = 0.12). Our findings are robust and broadly relevant. We found consistent statistical estimates based on a rigorous bootstrap approach and included all data from lakes under six meters average depth, a category that includes 89% of global lakes. These stoichiometric long-term relationships can improve quantitative nutrient management in lakes and their catchments through a nutrient-ratio-based strategy.

show abstract

Section: Mainmentioning

confidence: 99%

Consistent stoichiometric long-term relationships between nutrients and chlorophyll-a across lakes

Graeber,

McCarthy,

Shatwell

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…1 ). Of the inorganic, reactive N forms, ammonium-N is most energetically favorable for algal growth 17 , 18 , but concentration measurements are scarce and unreliable due to its bioreactivity 19 . Instead, we chose nitrate-N, as it is less energetically favorable, and thus more prone to accumulate at measurable concentrations, and more likely to accumulate over long-term periods 20 , 21 .…”

Section: Introductionmentioning

confidence: 99%

Consistent stoichiometric long-term relationships between nutrients and chlorophyll-a across shallow lakes

Graeber,

McCarthy,

Shatwell

et al. 2024

Nat Commun

Self Cite

View full text Add to dashboard Cite

Aquatic ecosystems are threatened by eutrophication from nutrient pollution. In lakes, eutrophication causes a plethora of deleterious effects, such as harmful algal blooms, fish kills and increased methane emissions. However, lake-specific responses to nutrient changes are highly variable, complicating eutrophication management. These lake-specific responses could result from short-term stochastic drivers overshadowing lake-independent, long-term relationships between phytoplankton and nutrients. Here, we show that strong stoichiometric long-term relationships exist between nutrients and chlorophyll a (Chla) for 5-year simple moving averages (SMA, median R² = 0.87) along a gradient of total nitrogen to total phosphorus (TN:TP) ratios. These stoichiometric relationships are consistent across 159 shallow lakes (defined as average depth < 6 m) from a cross-continental, open-access database. We calculate 5-year SMA residuals to assess short-term variability and find substantial short-term Chla variation which is weakly related to nutrient concentrations (median R² = 0.12). With shallow lakes representing 89% of the world’s lakes, the identified stoichiometric long-term relationships can globally improve quantitative nutrient management in both lakes and their catchments through a nutrient-ratio-based strategy.

show abstract

Subtropical stormwater ponds are more frequently net nitrogen fixing compared to natural ponds

Goeckner,

Smyth,

Holgerson

et al. 2024

Biogeochemistry

View full text Add to dashboard Cite

Urban stormwater ponds (SWPs) are engineered ecosystems designed to prevent flooding and protect downstream ecosystems by retaining nutrients associated with stormwater runoff, including nitrogen (N). Despite these expectations, multiple studies have found that SWPs have low N removal efficiencies and can be sources of N to downstream ecosystems. To understand mechanisms controlling the fate of N in SWPs, we quantified dinitrogen (N2) gas saturation to characterize net N2 exchange as either net denitrification or net N-fixation. We assessed temporal and spatial patterns of N2 dynamics in fifteen SWPs and six naturally occurring ponds in undisturbed watersheds (Florida, USA) by sampling in two seasons (dry and wet) and from multiple depths of the water column. Samples from SWPs were equally likely to exhibit N2 supersaturation (net denitrification; 50%) or undersaturation (net N-fixation; 50%). In contrast, the majority (82%) of samples from natural ponds were supersaturated with N2, indicating net denitrification. The mean SWP air–water N2 flux was − 1.7 μg N2-N m−2 h−1 (range − 500 to 433 μg N2-N m−2 h−1), which was lower than clear (40 μg N2-N m−2 h−1; range − 68 to 74 μg N2-N m−2 h−1) and humic (202 μg N2-N m−2 h−1; range 41 to 407 μg N2-N m−2 h−1) natural ponds despite considerably higher variation in SWPs. These results indicate that SWPs may have low N removal efficiencies in part due to N-fixation adding new N to the system. Overall, this study shows that SWPs are less effective than natural ponds at removing reactive N from the environment, potentially impacting downstream water quality.

show abstract

Effects of filtration timing and pore size on measured nutrient concentrations in environmental water samples

Cited by 6 publications

References 24 publications

Consistent stoichiometric long-term relationships between nutrients and chlorophyll-a across lakes

Consistent stoichiometric long-term relationships between nutrients and chlorophyll-a across lakes

Consistent stoichiometric long-term relationships between nutrients and chlorophyll-a across shallow lakes

Subtropical stormwater ponds are more frequently net nitrogen fixing compared to natural ponds

Contact Info

Product

Resources

About