Limnological Response of Las Curias Reservoir, San Juan, Puerto Rico: Successful Management of the Invasive Aquatic Fern, Salvinia molesta
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsReview of Water paper 2677873 Limnological Response of Las Curias Reservoir, San Juan Puerto Rico; Successful Management of Invasive Aquatic Fern Salvinia molesta
This is a well written paper on a topic of interest and is worthy of publication.
The following revisions should be made before the paper is published
In Line 27 the first sentence should list a starting date with 100% Salvinia coverage. The next sentence should give the date January 29 2021 with 71% coverage and an end of period date with the very low observed coverage.
In Line 28 remove the extraneous -1 after mg/L
In Section 2.1 Site description should include the history of the Las Curias reservoir beginning with its construction in 1946, the main purpose of the reservoir being a municipal water source, and a statement of the trophic state of the reservoir.
In Line 121 it is not clear whether all the harvested salvinia was deposited in the lake or whether any of the salvinia was deposited on a land surface. The sentence should be rewritten to make the location od disposal clear.
There are 13 references to changes over time that are expressed as a stated number-times less or more than a previous value. I do not regard this form of expression as proper scientific usage. The change over time should be expressed in each case as a percentage change from the original value.
These changes are needed in lines 207, 208, 212. 293, 294, 312, 313, 318, 320, 321.
Comments on the Quality of English LanguageSee above comments on correct usage of percent change to express trends
Author Response
Dear Reviewer,
We greatly value your thorough examination and the feedback provided to improve our manuscript. Herein, we outline in italics the rebuttal to each comment and describe the changes made to the manuscript:
- In Line 27 the first sentence should list a starting date with 100% Salvinia coverage. The next sentence should give the date January 29 2021 with 71% coverage and an end of period date with the very low observed coverage.
R: Agreed, correction made.
- Elimination of "-1" from mg/L:
R: Noted. We established "mg L^-1" in the manuscript. All instances have been corrected to "mg/L" as recommended.
- In Section 2.1 Site description should include the history of the Las Curias reservoir beginning with its construction in 1946, the main purpose of the reservoir being a municipal water source, and a statement of the trophic state of the reservoir.
R: Agreed. The historical details of Las Curias reservoir have been included. We also added a statement of the trophic state of the reservoir.
- In Line 121 it is not clear whether all the harvested salvinia was deposited in the lake or whether any of the salvinia was deposited on a land surface. The sentence should be rewritten to make the location on disposal clear.
R: Agreed, the location of salvinia disposal has been clarified.
- Usage of 'number-times' expression:
R: Understood. All instances using the 'number-times less/more' expression were revised and replaced with percentage changes as per your suggestion.
Additional reviewer comments:
- Abstract: L20: 176,974 m2 - site description L100: 19.2 ha
R: Agreed, change made. We established 176,974m2.
- Introduction : Missing is the rôle of submerged macrophytes respectively of phytoplankton, it is necessary to mention the competition of floating / submerged macrophytes and phytoplankton.
R: To address this concern, we have expanded our introduction section about the competition between floating/submerged macrophytes and phytoplankton.
- One problem is the there is no related information in the results concerning submerged macrophyte and phytoplankton, transparency point out no phytoplankton mass development, and maybe submerged macrophytes has not developed, but some information should be added to the text.
R: We added the suggested information on the discussion.
- Site description: No data are given to water depth...
R: Agreed, change made. We have incorporated a bathymetric map as suggested. Additionally, we provided details in the methods, results, and discussion sections regarding the alterations in the nominal capacity.
- Information of inflow (only diffuse discharge of rain water?) and outflow...
R: Agreed, we clarified the inflow and outflow dynamics.
- Results: The description of data and trends of data by `x-times less´ is not correct...
R: Agreed. To provide clarity, we have adjusted our descriptions and replaced the "x-times less" expressions with percentages throughout the paper..
- L 218: I am wondering about 12 m settled biomass of Salvinia – where, all over the lake bottom? How did the authors determine the thickness of the biomass? I cannot believe it……The reservoir has a maximum water depth of 19 m (see L461) and is covered by 12 m Salvinia – resting 7 m water body??
R: Agreed. We have expanded on our methodology and discussion to measure the thickness of sunken salvinia and other organic materials and provided additional context for clarity.
- L284: No abbreviation in the legends of figures/tables
R: Agreed, change made. C. salviniae was changed for Cyrtobagous salviniae.
- Table 1: Water Cspecific – what does this mean?*
R: Agreed, change made.
- Use fewer decimal places...
R: Agreed, change made across the document for temperature, conductivity and DO.
- Don´t use mean for pH, pH 6 and pH 7 are not 6.5 as mean!
R: We understand the reviewers thought pH being whole number based, however we do not entirely agree with their viewpoint. The instruments we use to measure pH are one or two decimal points, thus we need to round backwards to get whole numbers. Since the probe gives results in decimal points, we think that using decimal points when reporting values, including mean values, is acceptable. This article also is relating to Wahl et al 2020 to determine how pH changed. They report pH in decimals, thus our comparison of decimals to decimals is appropriate. While we understand the point of their review, we do not think it is appropriate for our results and not rounding them into whole numbers will result in a better understanding of how the ecosystem is recovering. No change applied.
- L 314: the peaking of water temperature in September is given by 4.7 °C in the figure 5d, but the author give a gradient of 5-6 °C – this should be corrected.
R: Agreed, correction made.
- L 410: mean pH = 7.73 – see above
R: This point refers to our decision on point 11 regarding pH values.
- L 415: mean dissolved oxygen – where?
R: Agreed, change made. Mean DO of the surface water.
- References: Please use the WATER format for references...
R: We have revised the references as per your suggestions and aligned them with the MDPI citation format in Zotero software.
Additional minor changes:
Figure 7 has been corrected. The data for secchi and rain accumulation had different date formats, which caused the secchi to not align properly with the representative rain bar. In addition, the size of the points in the secchi graph was excessively large, occasionally obscuring the standard error; this detail has also been rectified. An erroneous data point corresponding to October was identified and removed.
The maps in figure 3 were recreated for better resolution and visualization.
We hope that our revisions meet your expectations. We are truly grateful for your expert insights and believe they have greatly improved the quality of our work. Looking forward to further guidance.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper “Limnological Response of Las Curias Reservoir ….” is overall a well written paper, and after some corrections has a sufficient quality for publication in Water.
First of all, this is no Review!!! This is a case study of the Las Curias Reservoir, and the authors point out the `overcharging goal …. response of the Las Curia Reservoir during salvinia control project.´
Abstract: L20: 176,974 m2 - site description L100: 19.2 ha
Introduction : Missing is the rôle of submerged macrophytes respectively of phytoplankton, it is necessary to mention the competition of floating / submerged macrophytes and phytoplankton.
One problem is the there is no related information in the results concerning submerged macrophyte and phytoplankton, transparency point out no phytoplankton mass development, and maybe submerged macrophytes has not developed, but some information should be added to the text.
Site description: No data are given to water depth, a bathymetric maps should be added.
Information of inflow (only diffuse discharge of rain water?) and outflow (where is the water outlet, what about the outlet rate) are needed.
Results: The description of data and trends of data by `x-times less´ is not correct, this is a non-defined expression. (e.g., 10 apples are the basis, this means 10 apples are X, 2-times more are 20 apples (=2 X), 1 time less are zero apples (X - X = 0). Overall the expression x-times less is confusing. More understandable is to used percentages. This must be changed allover the paper.
L 218: I am wondering about 12 m settled biomass of Salvinia – where, all over the lake bottom? How did the authors determine the thickness of the biomass? I cannot believe it……
The reservoir has a maximum water depth of 19 m (see L461) and is covered by 12 m Salvinia – resting 7 m water body??
L284: No abbreviation in the legends of figures / tables
Table 1: Water Cspecific – what does this mean?
Use less decimal places – considering the accuracy of the methods, for conductivity no decimal places, for oxygen, pH and temperature only 1 decimal place, this must be changed all over the text.
Don´t use mean for pH, pH 6 and pH 7 are not 6.5 as mean!
L 314: the peaking of water temperature in September is given by 4.7 °C in the figure 5d, but the author give a gradient of 5-6 °C – this should be corrected.
L 410: mean pH = 7.73 – see above
L 415: mean dissolved oxygen – where?
References: Please use the WATER format for references, e.g. only for the first 15 references I have seen: L 535, L543, bold year; L 545 spaces; L 548 bold year; L 548: I think it is pp 40 (or 1-40)? L550 no pp; L550 bold year
Author Response
Dear Reviewer,
Thank you for the thorough review and valuable suggestions provided for our manuscript. Herein, we outline in italics the rebuttal to each comment and describe the changes made to the manuscript:
Response:
- Abstract: L20: 176,974 m2 - site description L100: 19.2 ha
R: Agreed, change made. We established 176,974m2.
- Introduction : Missing is the rôle of submerged macrophytes respectively of phytoplankton, it is necessary to mention the competition of floating / submerged macrophytes and phytoplankton.
R: To address this concern, we have expanded our introduction section about the competition between floating/submerged macrophytes and phytoplankton.
- One problem is the there is no related information in the results concerning submerged macrophyte and phytoplankton, transparency point out no phytoplankton mass development, and maybe submerged macrophytes has not developed, but some information should be added to the text.
R: We added the suggested information on the discussion.
- Site description: No data are given to water depth...
R: Agreed, change made. We have incorporated a bathymetric map as suggested. Additionally, we provided details in the methods, results, and discussion sections regarding the alterations in the nominal capacity.
- Information of inflow (only diffuse discharge of rain water?) and outflow...
R: Agreed, we clarified the inflow and outflow dynamics.
- Results: The description of data and trends of data by `x-times less´ is not correct...
R: Agreed. To provide clarity, we have adjusted our descriptions and replaced the "x-times less" expressions with percentages throughout the paper..
- L 218: I am wondering about 12 m settled biomass of Salvinia – where, all over the lake bottom? How did the authors determine the thickness of the biomass? I cannot believe it……The reservoir has a maximum water depth of 19 m (see L461) and is covered by 12 m Salvinia – resting 7 m water body??
R: Agreed. We have expanded on our methodology and discussion to measure the thickness of sunken salvinia and other organic materials and provided additional context for clarity.
- L284: No abbreviation in the legends of figures/tables
R: Agreed, change made. C. salviniae was changed for Cyrtobagous salviniae.
- Table 1: Water Cspecific – what does this mean?*
R: Agreed, change made.
- Use fewer decimal places...
R: Agreed, change made across the document for temperature, conductivity and DO.
- Don´t use mean for pH, pH 6 and pH 7 are not 6.5 as mean!
R: We understand the reviewers thought pH being whole number based, however we do not entirely agree with their viewpoint. The instruments we use to measure pH are one or two decimal points, thus we need to round backwards to get whole numbers. Since the probe gives results in decimal points, we think that using decimal points when reporting values, including mean values, is acceptable. This article also is relating to Wahl et al 2020 to determine how pH changed. They report pH in decimals, thus our comparison of decimals to decimals is appropriate. While we understand the point of their review, we do not think it is appropriate for our results and not rounding them into whole numbers will result in a better understanding of how the ecosystem is recovering. No change applied.
- L 314: the peaking of water temperature in September is given by 4.7 °C in the figure 5d, but the author give a gradient of 5-6 °C – this should be corrected.
R: Agreed, correction made.
- L 410: mean pH = 7.73 – see above
R: This point refers to our decision on point 11 regarding pH values.
- L 415: mean dissolved oxygen – where?
R: Agreed, change made. Mean DO of the surface water.
- References: Please use the WATER format for references...
R: We have revised the references as per your suggestions and aligned them with the MDPI citation format in Zotero software.
Additional reviewer comments:
- In Line 27 the first sentence should list a starting date with 100% Salvinia coverage. The next sentence should give the date January 29 2021 with 71% coverage and an end of period date with the very low observed coverage.
R: Agreed, correction made.
- Elimination of "-1" from mg/L:
R: Noted. We established "mg L^-1" in the manuscript. All instances have been corrected to "mg/L" as recommended.
- In Section 2.1 Site description should include the history of the Las Curias reservoir beginning with its construction in 1946, the main purpose of the reservoir being a municipal water source, and a statement of the trophic state of the reservoir.
R: Agreed. The historical details of Las Curias reservoir have been included. We also added a statement of the trophic state of the reservoir.
- In Line 121 it is not clear whether all the harvested salvinia was deposited in the lake or whether any of the salvinia was deposited on a land surface. The sentence should be rewritten to make the location on disposal clear.
R: Agreed, the location of salvinia disposal has been clarified.
- Usage of 'number-times' expression:
R: Understood. All instances using the 'number-times less/more' expression were revised and replaced with percentage changes as per your suggestion.
Additional minor changes:
* Figure 7 has been corrected. The data for secchi and rain accumulation had different date formats, which caused the secchi to not align properly with the representative rain bar. In addition, the size of the points in the secchi graph was excessively large, occasionally obscuring the standard error; this detail has also been rectified. An erroneous data point corresponding to October was identified and removed.
The maps in figure 3 were recreated for better resolution and visualization.
Thank you once again for your constructive feedback. We believe these revisions have significantly improved the quality of our manuscript and hope it meets the journal's standards.
Warm regards,
Xavier
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors considered most of the recommendations, ut there are still some mistakes / insufficient formulations in the text.
L 28/29/30: please write 17.6 ha etc. – the exact value in m2 is not so easy to readd.
L 31: chage to 2.4 mg L-1
L 274/275/275: the authors write: 165.6 g +/- 113.40 – it is not useful to give more decimal places for the SE than for the mean data
Table 1: pH are not whole number based, that is correct. But pH 7.2 means a H+ concentration of
10-7.2, and pH 6 = 10-6, to describe pH it is necessary to give the range (e.g. pH = 6.6 – 7.2), too because pH effects are given by the extremes.
What does it mean, the pH increased by 12 % and 5 % - what is the basis (these mean pH data do not have the same percentage basis), better write increase by x pH units.
For Specific conductivity, oxygen and water temperature you give more decimal places for the SE than for the mean data!
References – many mistakes: years are not in bold, at the end of the line ;.
This concerns the references: 5, 9, 11, 12, 22, 28, 30, 31, 32, 39 45, 46, 64, 65, 75, 78
Ref. 48: no year of publication
The references 34 – 38 do not give any information to the source. The different software release data must be putted in one reference as version number, access link
Ref. 42 and 43 dito, give source of the software and put the two versions in one reference (version number), access link
Ref. 44: no information about the version number, access link
Author Response
Dear Reviewer,
Thank you for your insightful comments and suggestions in this second round of the review. We have carefully considered each point and have made the corresponding revisions to our manuscript as detailed below:
- L 28/29/30: please write 17.6 ha etc. – the exact value in m^2 is not so easy to read.
Response: Agreed. We have changed the units to hectares (ha) in the abstract and results section for consistency.
- L 31: change to 2.4 mg L^-1.
Response: Agreed. The necessary correction has been made.
- L 274/275/275: the authors write: 165.6 g +/- 113.40 – it is not useful to give more decimal places for the SE than for the mean data.
Response: Agreed. We have made this change throughout the document, including the table.
- Table 1: pH are not whole numbers based, that is correct. But pH 7.2 means an H^+ concentration of 10^-7.2, and pH 6 = 10^-6, to describe pH it is necessary to give the range (e.g., pH = 6.6 – 7.2), too because pH effects are given by the extremes.
Response: Agreed. We have added the pH range in Table 1 as suggested.
- does it mean, the pH increased by 12 % and 5 % - what is the basis (these mean pH data do not have the same percentage basis), better write increase by x pH units.
Response: Agreed. The manuscript now reflects the increase in pH units. L 409 – 412.
- Original Comment: For Specific conductivity, oxygen, and water temperature you give more decimal places for the SE than for the mean data!
Response: Agreed. Corrections have been made throughout the document and tables to ensure consistency in decimal places.
- References – many mistakes: years are not in bold, at the end of the line ;. This concerns the references: 5, 9, 11, 12, 22, 28, 30, 31, 32, 39, 45, 46, 64, 65, 75, 78.
Response: Agreed. All identified errors in the references have been corrected.
- Ref. 48: no year of publication.
Response: The year of publication has been added to reference. Reference 43.
- The references 34 – 38 do not give any information about the source. The different software release data must be put in one reference as version number, access link.
Response: The Esri software is now referenced under a single citation, but I emphasize that I cannot include more than one link per citation in Zotero. A link to Esri's page has been included, where the latest versions of the software can be obtained. The same has been done for R. Additionally, a specific link has been integrated into the Python reference. References 34, 38, and 39.
- 42 and 43 dito, give the source of the software and put the two versions in one reference (version number), access link.
Response: Agreed. References have been consolidated into one reference with the appropriate version number and access link. References 34 and 38.
- Ref. 44: no information about the version number, access link.
Response: Agreed. The version number and access link have been included in the reference. Reference 39.
We appreciate the opportunity to enhance our manuscript and thank you again for your constructive feedback. Please do not hesitate to contact us should there be any further queries or clarifications needed.
Sincerely,
Mr. García López and Coauthors
Author Response File: Author Response.pdf
