manuscript/f1000_revisions/wilson_comments.md
In USEPA/Microcystinchla: Code, Data, and Manuscript for NLA, microcystin, Chl analysis
Title and Abstract:
For clarity, the authors might consider replacing “various” with “World Health Organization and U.S. Environmental Protection Agency”.
Article content:
Using publicly available data produced from the 2007 USEPA National Lakes Assessment, the authors use conditional probability analysis to develop four chlorophyll concentration thresholds associated with two USEPA microcystin drinking water advisory targets, one WHO microcystin drinking water advisory target, and one WHO microcystin recreational use target. For most water resource managers, chlorophyll is much easier and cheaper to measure than microcystin. Given the threat that microcystins pose to human health, the purpose of this study is valuable. With that said, this study significantly overlaps with Yuan et al. (2014). The current study adds new advisory microcystin targets recently established by USEPA and uses a different statistical approach than Yuan et al. 2014. The authors cite relatively few studies. I think the authors need to more broadly consider the existing literature and describe how their findings relate to and build from past studies. Below, I provide some related studies that the authors might want to consider. I am certain that I have missed other relevant studies.
Ahn et al. (2011)
Beaver et al. (2014)
Chan et al. (2007)
Conti et al. (2005)
Dolman et al. (2012)
Downing et al. (2000)
Giani et al. (2005)
Graham et al. (2004)
Graham et al. (2010)
Jacoby et al. (2015)
Kotak et al. (2000)
Marion et al. (2012)
Orihel et al. (2012)
Sarnelle et al. (2010)
Scott and Haggard (2015)
Sinang et al. (2015)
Stow et al. (2015)
Su et al. (2015)
Yuan and Pollard et al. (2015)
Based on the 2007 National Lakes Assessment report, roughly two-thirds of the waterbodies reported no detectable microcystin (detection limit = 0.05 ug/L) despite covering a huge range of chlorophyll concentrations. And, Fig 2 suggests that a large number of sites had barely detectable concentration of microcystin across a wide range of chlorophyll. It is not clear from the text how the authors dealt with waterbodies with undetectable or barely detectable microcystin concentrations.
Presenting histograms of chlorophyll and microcystin concentrations for the study lakes would be useful.
I am not an expert on conditional probability analysis. Based on the authors’ text (second paragraph in Analytical Methods section), it appears that this analysis considers multiple events over time. If their dataset includes single measurements in a waterbody, I don’t understand where the temporal component comes into the analysis. Again, I could be totally misunderstanding how this analysis works and should probably read the relevant references the authors provided.
Based on increasing error in the conditional probability plots as chlorophyll increases, the reported chlorophyll thresholds should not include significant digits (i.e., ± 0.1) but instead be whole numbers.
I would organize the information in table 1 by either concentration (low to high) or advisory type (drinking or recreational) and concentration (low to high). It might also be useful to include the number of lakes represented in each category based on microcystin. In table 2, I would add the specific microcystin concentration target under each advisory type to avoid having to look back at table 1 for these data.
Conclusions:
The purpose of this study is to use a simple measurement (chlorophyll) to determine the threat that microcystins pose to a waterbody relative to existing microcystin concentration targets. Most waterbodies lacked microcystin and Figure 2 clearly shows that there are a huge number of waterbodies across a large chlorophyll range that apparently had microcystin concentrations at the detection limit of 0.05 ug/L. I am concerned about the microcystin data at the detection limit. They appear to be false positives. I agree with the authors who acknowledged that high chlorophyll is not always a good predictor of high microcystin. What should be done for those waterbodies with high concentrations of chlorophyll but that had no or barely detectable microcystin?
Data:
I am confused about the data collected and available for the 2007 National Lakes Assessment. For example, I organized this dataset in July 2010 and found that 1158 lakes were sampled once (1152 of these lakes included data for both chlorophyll and microcystin) and 95 of the 1158 originally sampled lakes were sampled a second time in 2007. Yuan et al. 2014 (Freshwater Biology) used data for 1077 sampled lakes. The current study (as well as the National Lakes Assessment website and report) describes data for 1028 lakes. Clarity about these discrepancies is not necessarily the authors’ job, but it would be good to understand why the differences exist across these datasets. Also, for this study, how were data used for lakes sampled twice in 2007?
Although all of the National Lakes Assessment data are publicly available, the authors should provide the dataset that they used for this study.
References
1. Ahn C, Oh H, Park Y: EVALUATION OF ENVIRONMENTAL FACTORS ON CYANOBACTERIAL BLOOM IN EUTROPHIC RESERVOIR USING ARTIFICIAL NEURAL NETWORKS1. Journal of Phycology. 2011; 47 (3): 495-504 Publisher Full Text
2. Beaver J, Manis E, Loftin K, Graham J, Pollard A, Mitchell R: Land use patterns, ecoregion, and microcystin relationships in U.S. lakes and reservoirs: A preliminary evaluation. Harmful Algae. 2014; 36: 57-62 Publisher Full Text
3. Chan WS, Recknagel F, Cao H, Park HD: Elucidation and short-term forecasting of microcystin concentrations in Lake Suwa (Japan) by means of artificial neural networks and evolutionary algorithms.Water Res. 2007; 41 (10): 2247-55 PubMed Abstract | Publisher Full Text
4. Conti AL, Guerrero JM, Regueira JM: Levels of microcystins in two Argentinean reservoirs used for water supply and recreation: differences in the implementation of safe levels.Environ Toxicol. 2005; 20 (3): 263-9 PubMed Abstract | Publisher Full Text
5. Dolman AM, Rücker J, Pick FR, Fastner J, Rohrlack T, Mischke U, Wiedner C: Cyanobacteria and cyanotoxins: the influence of nitrogen versus phosphorus.PLoS One. 2012; 7 (6): e38757 PubMed Abstract | Publisher Full Text
6. Downing J, Watson S, McCauley E: Predicting Cyanobacteria dominance in lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2001; 58 (10): 1905-1908 Publisher Full Text
7. Giani A, Bird D, Prairie Y, Lawrence J: Empirical study of cyanobacterial toxicity along a trophic gradient of lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2005; 62 (9): 2100-2109 Publisher Full Text
8. Graham JL, Jones JR, Jones SB, Downing JA, Clevenger TE: Environmental factors influencing microcystin distribution and concentration in the Midwestern United States.Water Res. 2004; 38 (20): 4395-404 PubMed Abstract | Publisher Full Text
9. Graham JL, Loftin KA, Meyer MT, Ziegler AC: Cyanotoxin mixtures and taste-and-odor compounds in cyanobacterial blooms from the Midwestern United States.Environ Sci Technol. 2010; 44 (19): 7361-8 PubMed Abstract | Publisher Full Text
10. Jacoby J, Burghdoff M, Williams G, Read L, Hardy J: Dominant factors associated with microcystins in nine midlatitude, maritime lakes. Inland Waters. 2015; 5 (2): 187-202 Publisher Full Text
11. Kotak B, Lam A, Prepas E, Hrudey S: Role of chemical and physical variables in regulating microcystin-LR concentration in phytoplankton of eutrophic lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2000; 57 (8): 1584-1593 Publisher Full Text
12. Marion JW, Lee J, Wilkins JR, Lemeshow S, Lee C, Waletzko EJ, Buckley TJ: In vivo phycocyanin flourometry as a potential rapid screening tool for predicting elevated microcystin concentrations at eutrophic lakes.Environ Sci Technol. 2012; 46 (8): 4523-31 PubMed Abstract | Publisher Full Text
13. Orihel D, Bird D, Brylinsky M, Chen H, Donald D, Huang D, Giani A, Kinniburgh D, Kling H, Kotak B, Leavitt P, Nielsen C, Reedyk S, Rooney R, Watson S, Zurawell R, Vinebrooke R, Smith R: High microcystin concentrations occur only at low nitrogen-to-phosphorus ratios in nutrient-rich Canadian lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2012; 69 (9): 1457-1462 Publisher Full Text
14. Sarnelle O, Morrison J, Kaul R, Horst G, Wandell H, Bednarz R: Citizen monitoring: Testing hypotheses about the interactive influences of eutrophication and mussel invasion on a cyanobacterial toxin in lakes.Water Res. 2010; 44 (1): 141-50 PubMed Abstract | Publisher Full Text
15. Scott JT, Haggard BE: Implementing Effects-Based Water Quality Criteria for Eutrophication in Beaver Lake, Arkansas: Linking Standard Development and Assessment Methodology.J Environ Qual. 2015; 44 (5): 1503-12 PubMed Abstract | Publisher Full Text
16. Sinang S, Reichwaldt E, Ghadouani A: Local nutrient regimes determine site-specific environmental triggers of cyanobacterial and microcystin variability in urban lakes. Hydrology and Earth System Sciences. 2015; 19 (5): 2179-2195 Publisher Full Text
17. Stow CA, Cha Y, Johnson LT, Confesor R, Richards RP: Long-term and seasonal trend decomposition of Maumee River nutrient inputs to western Lake Erie.Environ Sci Technol. 2015; 49 (6): 3392-400 PubMed Abstract | Publisher Full Text
18. Su X, Xue Q, Steinman AD, Zhao Y, Xie L: Spatiotemporal Dynamics of Microcystin Variants and Relationships with Environmental Parameters in Lake Taihu, China.Toxins (Basel). 2015; 7 (8): 3224-44 PubMed Abstract | Publisher Full Text
19. Yuan L, Pollard A: Deriving nutrient targets to prevent excessive cyanobacterial densities in U.S. lakes and reservoirs. Freshwater Biology. 2015; 60 (9): 1901-1916 Publisher Full Text
20. Yuan L, Pollard A, Pather S, Oliver J, D'Anglada L: Managing microcystin: identifying national-scale thresholds for total nitrogen and chlorophylla. Freshwater Biology. 2014; 59 (9): 1970-1981 Publisher Full Text
USEPA/Microcystinchla documentation built on May 9, 2019, 5:23 p.m.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
Title and Abstract: For clarity, the authors might consider replacing “various” with “World Health Organization and U.S. Environmental Protection Agency”.
Article content: Using publicly available data produced from the 2007 USEPA National Lakes Assessment, the authors use conditional probability analysis to develop four chlorophyll concentration thresholds associated with two USEPA microcystin drinking water advisory targets, one WHO microcystin drinking water advisory target, and one WHO microcystin recreational use target. For most water resource managers, chlorophyll is much easier and cheaper to measure than microcystin. Given the threat that microcystins pose to human health, the purpose of this study is valuable. With that said, this study significantly overlaps with Yuan et al. (2014). The current study adds new advisory microcystin targets recently established by USEPA and uses a different statistical approach than Yuan et al. 2014. The authors cite relatively few studies. I think the authors need to more broadly consider the existing literature and describe how their findings relate to and build from past studies. Below, I provide some related studies that the authors might want to consider. I am certain that I have missed other relevant studies.
Ahn et al. (2011) Beaver et al. (2014) Chan et al. (2007) Conti et al. (2005) Dolman et al. (2012) Downing et al. (2000) Giani et al. (2005) Graham et al. (2004) Graham et al. (2010) Jacoby et al. (2015) Kotak et al. (2000) Marion et al. (2012) Orihel et al. (2012) Sarnelle et al. (2010) Scott and Haggard (2015) Sinang et al. (2015) Stow et al. (2015) Su et al. (2015) Yuan and Pollard et al. (2015)
Based on the 2007 National Lakes Assessment report, roughly two-thirds of the waterbodies reported no detectable microcystin (detection limit = 0.05 ug/L) despite covering a huge range of chlorophyll concentrations. And, Fig 2 suggests that a large number of sites had barely detectable concentration of microcystin across a wide range of chlorophyll. It is not clear from the text how the authors dealt with waterbodies with undetectable or barely detectable microcystin concentrations.
Presenting histograms of chlorophyll and microcystin concentrations for the study lakes would be useful.
I am not an expert on conditional probability analysis. Based on the authors’ text (second paragraph in Analytical Methods section), it appears that this analysis considers multiple events over time. If their dataset includes single measurements in a waterbody, I don’t understand where the temporal component comes into the analysis. Again, I could be totally misunderstanding how this analysis works and should probably read the relevant references the authors provided.
Based on increasing error in the conditional probability plots as chlorophyll increases, the reported chlorophyll thresholds should not include significant digits (i.e., ± 0.1) but instead be whole numbers.
I would organize the information in table 1 by either concentration (low to high) or advisory type (drinking or recreational) and concentration (low to high). It might also be useful to include the number of lakes represented in each category based on microcystin. In table 2, I would add the specific microcystin concentration target under each advisory type to avoid having to look back at table 1 for these data.
Conclusions: The purpose of this study is to use a simple measurement (chlorophyll) to determine the threat that microcystins pose to a waterbody relative to existing microcystin concentration targets. Most waterbodies lacked microcystin and Figure 2 clearly shows that there are a huge number of waterbodies across a large chlorophyll range that apparently had microcystin concentrations at the detection limit of 0.05 ug/L. I am concerned about the microcystin data at the detection limit. They appear to be false positives. I agree with the authors who acknowledged that high chlorophyll is not always a good predictor of high microcystin. What should be done for those waterbodies with high concentrations of chlorophyll but that had no or barely detectable microcystin?
Data: I am confused about the data collected and available for the 2007 National Lakes Assessment. For example, I organized this dataset in July 2010 and found that 1158 lakes were sampled once (1152 of these lakes included data for both chlorophyll and microcystin) and 95 of the 1158 originally sampled lakes were sampled a second time in 2007. Yuan et al. 2014 (Freshwater Biology) used data for 1077 sampled lakes. The current study (as well as the National Lakes Assessment website and report) describes data for 1028 lakes. Clarity about these discrepancies is not necessarily the authors’ job, but it would be good to understand why the differences exist across these datasets. Also, for this study, how were data used for lakes sampled twice in 2007?
Although all of the National Lakes Assessment data are publicly available, the authors should provide the dataset that they used for this study.
References 1. Ahn C, Oh H, Park Y: EVALUATION OF ENVIRONMENTAL FACTORS ON CYANOBACTERIAL BLOOM IN EUTROPHIC RESERVOIR USING ARTIFICIAL NEURAL NETWORKS1. Journal of Phycology. 2011; 47 (3): 495-504 Publisher Full Text 2. Beaver J, Manis E, Loftin K, Graham J, Pollard A, Mitchell R: Land use patterns, ecoregion, and microcystin relationships in U.S. lakes and reservoirs: A preliminary evaluation. Harmful Algae. 2014; 36: 57-62 Publisher Full Text 3. Chan WS, Recknagel F, Cao H, Park HD: Elucidation and short-term forecasting of microcystin concentrations in Lake Suwa (Japan) by means of artificial neural networks and evolutionary algorithms.Water Res. 2007; 41 (10): 2247-55 PubMed Abstract | Publisher Full Text 4. Conti AL, Guerrero JM, Regueira JM: Levels of microcystins in two Argentinean reservoirs used for water supply and recreation: differences in the implementation of safe levels.Environ Toxicol. 2005; 20 (3): 263-9 PubMed Abstract | Publisher Full Text 5. Dolman AM, Rücker J, Pick FR, Fastner J, Rohrlack T, Mischke U, Wiedner C: Cyanobacteria and cyanotoxins: the influence of nitrogen versus phosphorus.PLoS One. 2012; 7 (6): e38757 PubMed Abstract | Publisher Full Text 6. Downing J, Watson S, McCauley E: Predicting Cyanobacteria dominance in lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2001; 58 (10): 1905-1908 Publisher Full Text 7. Giani A, Bird D, Prairie Y, Lawrence J: Empirical study of cyanobacterial toxicity along a trophic gradient of lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2005; 62 (9): 2100-2109 Publisher Full Text 8. Graham JL, Jones JR, Jones SB, Downing JA, Clevenger TE: Environmental factors influencing microcystin distribution and concentration in the Midwestern United States.Water Res. 2004; 38 (20): 4395-404 PubMed Abstract | Publisher Full Text 9. Graham JL, Loftin KA, Meyer MT, Ziegler AC: Cyanotoxin mixtures and taste-and-odor compounds in cyanobacterial blooms from the Midwestern United States.Environ Sci Technol. 2010; 44 (19): 7361-8 PubMed Abstract | Publisher Full Text 10. Jacoby J, Burghdoff M, Williams G, Read L, Hardy J: Dominant factors associated with microcystins in nine midlatitude, maritime lakes. Inland Waters. 2015; 5 (2): 187-202 Publisher Full Text 11. Kotak B, Lam A, Prepas E, Hrudey S: Role of chemical and physical variables in regulating microcystin-LR concentration in phytoplankton of eutrophic lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2000; 57 (8): 1584-1593 Publisher Full Text 12. Marion JW, Lee J, Wilkins JR, Lemeshow S, Lee C, Waletzko EJ, Buckley TJ: In vivo phycocyanin flourometry as a potential rapid screening tool for predicting elevated microcystin concentrations at eutrophic lakes.Environ Sci Technol. 2012; 46 (8): 4523-31 PubMed Abstract | Publisher Full Text 13. Orihel D, Bird D, Brylinsky M, Chen H, Donald D, Huang D, Giani A, Kinniburgh D, Kling H, Kotak B, Leavitt P, Nielsen C, Reedyk S, Rooney R, Watson S, Zurawell R, Vinebrooke R, Smith R: High microcystin concentrations occur only at low nitrogen-to-phosphorus ratios in nutrient-rich Canadian lakes. Canadian Journal of Fisheries and Aquatic Sciences. 2012; 69 (9): 1457-1462 Publisher Full Text 14. Sarnelle O, Morrison J, Kaul R, Horst G, Wandell H, Bednarz R: Citizen monitoring: Testing hypotheses about the interactive influences of eutrophication and mussel invasion on a cyanobacterial toxin in lakes.Water Res. 2010; 44 (1): 141-50 PubMed Abstract | Publisher Full Text 15. Scott JT, Haggard BE: Implementing Effects-Based Water Quality Criteria for Eutrophication in Beaver Lake, Arkansas: Linking Standard Development and Assessment Methodology.J Environ Qual. 2015; 44 (5): 1503-12 PubMed Abstract | Publisher Full Text 16. Sinang S, Reichwaldt E, Ghadouani A: Local nutrient regimes determine site-specific environmental triggers of cyanobacterial and microcystin variability in urban lakes. Hydrology and Earth System Sciences. 2015; 19 (5): 2179-2195 Publisher Full Text 17. Stow CA, Cha Y, Johnson LT, Confesor R, Richards RP: Long-term and seasonal trend decomposition of Maumee River nutrient inputs to western Lake Erie.Environ Sci Technol. 2015; 49 (6): 3392-400 PubMed Abstract | Publisher Full Text 18. Su X, Xue Q, Steinman AD, Zhao Y, Xie L: Spatiotemporal Dynamics of Microcystin Variants and Relationships with Environmental Parameters in Lake Taihu, China.Toxins (Basel). 2015; 7 (8): 3224-44 PubMed Abstract | Publisher Full Text 19. Yuan L, Pollard A: Deriving nutrient targets to prevent excessive cyanobacterial densities in U.S. lakes and reservoirs. Freshwater Biology. 2015; 60 (9): 1901-1916 Publisher Full Text 20. Yuan L, Pollard A, Pather S, Oliver J, D'Anglada L: Managing microcystin: identifying national-scale thresholds for total nitrogen and chlorophylla. Freshwater Biology. 2014; 59 (9): 1970-1981 Publisher Full Text
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
Embedding an R snippet on your website
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.