Zooplankton Community Structure in Shallow Saline Steppe Inland Waters
Round 1
Reviewer 1 Report
The work is written in a standard way. All text is spelled correctly. The introduction justifies the need for research. The methods are correct, so are the statistics. The results are presented as standard. The authors discuss all important and less important results. However, the aim of the work and conclusions are not very original. The authors explain nothing new, but rather confirm other research results. E.g "All results confirm the hypothesis that both chemical composition, salinity and trophic state have a significant effect on zooplankton density and community structure". It is not novel, it is very common at least since 50 years. This work can be used as a comparison to other research, I think so. So it's hard for me to decide, I will leave the decisions to the editor.
Author Response
Thank you for your comprehensive evaluation, comments.
Article title changed. New title:
Zooplankton community structure in shallow saline steppe inland waters
The novelty of the work lies in the fact that we conducted a study in a large-scale geographical region where data on the zooplankton population of shallow, steppe salt waters have not been available so far.
Our goal was to register the dominant as well as indicator organisms found in the rotifer and microcrustaea assemblages in these undisturbed, natural aquatic ecosystems. These results can serve as a basis for further survey of the area. As these include semistatic and summer-drying intermittent water bodies, only the spring aspect of the zooplankton community was measured by a single sampling, no temporal changes were made.
Our data could only have been compared in nature to other, medium or large lakes. Most of these water bodies are under some kind of regulation, anthropogenic influence, so we refrained from comparison. Appropriate literature references have been made to illustrate the relationships between salinity and zooplankton. Please evaluate the new version of the article in the light of the changes made.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Changes in the zooplankton community structure, taxonomic and functional diversity along salinity gradient in shallow saline steppe lakes
Zsuga et al. 2021
Summary:
The paper outlines the species and community assemblages of zooplankton across the shallow saline lakes of the steppe region of Central Asia. Samples were taken across a geographic and salinity gradient to examine species assemblage changes as related to certain environmental properties, in particular salinity. This study’s main contribution to the literature is a taxonomic overview of zooplankton specie that inhabit these unusual and somewhat inaccessible habitats across the Central Asian steppe. The authors make several hypotheses about species’ presence in different environments with broad strokes as they pertain to previous knowledge defined for those zooplankton groups, e.g., Artemia monodominate saline environments because they are halinophiles. The authors also attempt to make conclusions about trophic structure in these small ecosystems based on the zooplankton present.
Broad comments:
Strengths:
The additional taxonomic understanding we get from this addition is quite significant. These ecosystems are unique, and their species assemblages are not collected in such a concerted way across such a large stretch of land. This is especially important given the accelerated climate change of the region. Though none of the species in particular are ‘surprising,’ in my opinion, the catalogue generated in this study gives insight as to the natural history of vernal pools/transient aquatic environments in the Central Asian steppe. The authors are also adding an important amount of biophysicochemical properties of these ecosystems to the literature. Although they are, what appear to be, singular measurements, the abiotic factors measured in this study provide important baseline data for many aspects of these environments.
Weaknesses:
Although I appreciate and value the data and analyses presented here, the additions are really only a survey of taxonomy and the environment. Although this is incredibly valuable data, I am less confident in the ability to pull some of these conclusions out of the data as presented. For example, these are singular measurements of transient systems. There is little information about how succession or assemblages change throughout the season. I would have liked to have seen some sort of time series data and subsequent analyses to truly understand the dominant players in these systems. We know that portfolio effects and boom-bust dynamics govern these systems, so depending on the happenstance of the sampling day, we could be seeing very different results than the actual biological reality.
As for the climate correlation analyses, I do not see where the authors have made an effort to do any corrections for multiple comparisons, e.g., Bonferroni. In the Spearman matrix, there are 6x20 comparisons—at least *some* of those may be spurious due to the number of tests implemented. I also must confess I do not fully understand the intention behind the authors’ use of PCA in this study. I could understand if using PCA to compress the number of comparisons in the environment—that makes sense to me—I do not understand the conclusion (from table 3) that rotifers, cladocerans, copepods, chlorophyll, and total organic carbon are positively correlated with PC1 and Artemia and TDS negatively. This is not a conclusion but a product of the data you have given the PCA. What you could say is that all crustacea (less Artemia), chlorophyll, and TOC are the most common features of all of your ecosystems together—but I am unconvinced that is a useful conclusion—that is nearly 50% of the variables you collected—at best you could say the systems are similar? I also never see reported the amount of variation explained by any of the PCs. I am confused by the use of this analysis in particular, and if the authors are intending to use it to explain a particular point, I encourage them to revisit the text there, else I missed it.
I would also caution the authors in their interpretation of functional feeding traits. Particularly in the transbaikalian region, we see zooplankton adopting feeding strategies not common to their sister taxa in other environments. The assumptions in these analyses are that these organisms are feeding in the same modes as have been previously noted in other systems—this may not be the case but certainly deserves more attention. For example, in the Baikal watershed, we see calanoids that are notoriously carnivorous instead exhibiting herbivory only and sometimes omnivory because of the unique species assemblages these environments contain. Not to say that all of these conclusions are not valid—in fact, I agree with most of them, especially that Artemia dominated systems de facto have simple trophic systems—but these conclusions deserve more exploration before necessarily being accepted as the contribution—possibly more in the discussion about this?
I would also caution the authors in using the terminology “lakes” to describe these ecosystems. Although many of them seem to be vernal pools, some of them also seem to be permanent—that is unclear from the manuscript. I would at least recommend switching to “ponds” based on the depth (Z) of these systems. If light reaches the sediment bank, which in this case, I believe, is always true, the proper terminology is “pond,” unless vernal pool is more appropriate.
Specific comments:
The manuscript needs significant English editing in terms of both diction and grammar. This is by no means a fatal flaw but will certainly need work before publication in an English language journal.
Figures/Tables:
Figure 1. Line 86 Can you show the sampling points on the map of Kazakhstan? It is difficult to place the outset into the map itself. For example, it is difficult to see how promixal these lakes are to the Russian Federation border.
Figures 2 & 3, lines 189 and 209—there is almost no information in the figure caption. In particular, does each point represent a sample? A lake? Is that the same thing? In figure three, you have defined the distinct clusters, but never tell us what they are. I assume they correspond to haline designations that you talk about elsewhere in the manuscript, but these figures need more information to make them useful.
Figure 4 line 234—I would caution the use of logarithmic models to describe what you are seeing here. You even mention in the lit review that the upper tolerance of these zooplankton in general is rather low compared to that of Artemia—the relationships here look especially weighted by those 0 values—did you try linear models? How did they fair?
Table 5, line 278 et al—These tables are useful, but I would also be interested in seeing abundance data. This is just reporting presence/absence.
Figure 6, line 292—I don’t understand how these data are represented. You are saying that this species occurred in salinity ranges from TDSmin-TDSmax—would this be better represented in a table or some sort? I do not understand putting it in a graph such as this.
Introduction:
Lines 66-68—this is the actual thesis of the study. I would expound upon the importance of that and shy away from more of the analyses and interpretation of feeding guild and functional diversity. This thesis is the point of the study and the contribution to the literature. The potentially spurious analysis an overinterpretation of the data distracts from this contribution! It is absolutely true, too! We have SO much data on large lakes in the region and almost nothing is known about the smaller aquatic systems that could be crucial local refugia from the larger systems of the region. Their connections and overlap are potentially very interesting and important to resilience.
Methods:
See above comments in Broad section to address data analyses.
Results/Discussion:
There are multiple points where causation is derived from correlation—I would be careful there. The environment very likely is dictating the species assemblages, but I would be cautious about drawing conclusions such as those at Lines 205-206, “salinity causes a decrease in the taxon richness.” That is a correlation to salinity, but until that hypothesis is tested, I would caution making statements such as that—there are several of these in the results section: lines 217-219, line 226, lines 238, et cetera. Speaking in these absolutes without proper hypothesis testing leads to inconsistencies in the literature.
It is difficult to say whether salinity is causing the change in functional diversity or is salinity is preferencing a dominance of a particular species which then dictates species dynamics. For example, does salinity cause a simpler trophic system or is Artemia the only organism that is successful as a predator in some systems because of present or historical conditions.
Conclusion:
The conclusion largely focuses on comparisons and analyses done, but I think it would be more opportune to talk about the species assemblages and diversity present and wrap back around to the importance of understanding the ecosystems as they are very likely going to experience large swings in climate. The English in this section in particular is weak, and I think obscures the threads the authors want to showcase most. Again, I would caution saying this in absolutes without prior testing such as Lines 402-403, “large size zooplankton organisms can adapt better, than small one.” Not only is this unsupported by the current study, but likely is not true in general. I am unsure about some of these statements in the conclusion section; they seem to be unrelated to the goals of the manuscript overall and are a detriment to the study/data at hand.
Author Response
Thank you for your comprehensive evaluation and valuable comments and suggestions.
Our oblique answers are given below.
1- The line numbers referenced in the answers correspond to the new version
| Evaluation, comments, old serial numbers |
Answer, changes |
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Article title changed. New title: Zooplankton community structure in shallow saline steppe inland waters |
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The summary and introduction contain minor fixes. The purpose of the research is presented in detail in the introduction Line 15-77 |
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There is little information about how succession or assemblages change throughout the season. I would have liked to have seen some sort of time series data and subsequent analyses to truly understand the dominant players in these systems. |
No studies have been performed on the seasonal evolution of time changes, taking into account the following. Considering their hydrological regime, the waters are intermittent and semistatic with small volumes, their water level can significantly decrease in July, while some of them might even dry out, the sampling was done in the spring. The weather conditions (temperature, precipitation) at both periods were similar. |
| Criticism of PCA we have clarified the terminology as follows | This analysis has been removed from the article |
| I would also caution the authors in their interpretation of functional feeding traits. | Understanding your comments, the insufficiently thorough and thoughtful analysis, we have taken the Functional analysis part out of the article. Line 297-375 |
| I would at least recommend switching to “ponds” based nt he depth (Z) of these systems. | We have clarified the terminology as follows:In terms of water balance, the aquatic ecosystems studied are classified as semistatic and astatic intermittent shallow waters including lakes, ponds pans and playas according to the terminological classification. |
| The manuscript needs significant English editing in terms of both diction and grammar. | The English language has been revised |
| Figure 1. Line 86 | Line 101. Sampling points are marked on the map |
| Figures 2 Line 189 | Figure 2 192, legend replaced |
| New Figure 3 Line 215 Percent abundance of zooplankton groups in waterbodies along the salinity gradient | |
| Figure 3 Line 209 | This figure was given a new serial number Figure 4,Line 223 because a new figure 3 was inserted in front of it. Legend replaced. |
| Figure 4 Line 234 | New number Figure 5 Line 247linear model was tried but was not correctThere is Nonlinear relationship between salinity and taxon diversity |
| Table 5 Line 278 |
New number Table 4 Line 267 List of Rotifera taxa along the salinity gradient Abundance data were also loaded into the table |
| New Table 5 Line 296 List of Cladocera taxa along the salinity gradientNew Table 6 Line 313 List of Copepoda taxa along the salinity gradientNew Table 7 Line 324 List of Artemia along the salinity gradient | |
| Lines 66-68 Actual thesis of study | We precisely defined the purpose of the studyLine 69-77 |
| 3.3.4. Grouping of waters according to zooplankton species compositionIn this new chapter, we grouped the studied waters based on the composition of the zooplankton communityLine 327-347 | |
| Figure 6 Line 334 Similarity of water bodies based on species composition | |
| Conclusion | This section has been clarifiedLine 349-364 |
| References | Line 385-453 The numbering has been changed in line with the recast |
Please evaluate the new version of the article in the light of the changes made.
Thank you for your comprehensive evaluation and valuable comments and suggestions.
Our oblique answers are given below.
1- The line numbers referenced in the answers correspond to the new version
| Evaluation, comments, old serial numbers |
Answer, changes |
|
|
Article title changed. New title: Zooplankton community structure in shallow saline steppe inland waters |
|
|
The summary and introduction contain minor fixes. The purpose of the research is presented in detail in the introduction Line 15-77 |
|
There is little information about how succession or assemblages change throughout the season. I would have liked to have seen some sort of time series data and subsequent analyses to truly understand the dominant players in these systems. |
No studies have been performed on the seasonal evolution of time changes, taking into account the following. Considering their hydrological regime, the waters are intermittent and semistatic with small volumes, their water level can significantly decrease in July, while some of them might even dry out, the sampling was done in the spring. The weather conditions (temperature, precipitation) at both periods were similar. |
| Criticism of PCA we have clarified the terminology as follows | This analysis has been removed from the article |
| I would also caution the authors in their interpretation of functional feeding traits. | Understanding your comments, the insufficiently thorough and thoughtful analysis, we have taken the Functional analysis part out of the article. Line 297-375 |
| I would at least recommend switching to “ponds” based nt he depth (Z) of these systems. | We have clarified the terminology as follows:In terms of water balance, the aquatic ecosystems studied are classified as semistatic and astatic intermittent shallow waters including lakes, ponds pans and playas according to the terminological classification. |
| The manuscript needs significant English editing in terms of both diction and grammar. | The English language has been revised |
| Figure 1. Line 86 | Line 101. Sampling points are marked on the map |
| Figures 2 Line 189 | Figure 2 192, legend replaced |
| New Figure 3 Line 215 Percent abundance of zooplankton groups in waterbodies along the salinity gradient | |
| Figure 3 Line 209 | This figure was given a new serial number Figure 4,Line 223 because a new figure 3 was inserted in front of it. Legend replaced. |
| Figure 4 Line 234 | New number Figure 5 Line 247linear model was tried but was not correctThere is Nonlinear relationship between salinity and taxon diversity |
| Table 5 Line 278 |
New number Table 4 Line 267 List of Rotifera taxa along the salinity gradient Abundance data were also loaded into the table |
| New Table 5 Line 296 List of Cladocera taxa along the salinity gradientNew Table 6 Line 313 List of Copepoda taxa along the salinity gradientNew Table 7 Line 324 List of Artemia along the salinity gradient | |
| Lines 66-68 Actual thesis of study | We precisely defined the purpose of the studyLine 69-77 |
| 3.3.4. Grouping of waters according to zooplankton species compositionIn this new chapter, we grouped the studied waters based on the composition of the zooplankton communityLine 327-347 | |
| Figure 6 Line 334 Similarity of water bodies based on species composition | |
| Conclusion | This section has been clarifiedLine 349-364 |
| References | Line 385-453 The numbering has been changed in line with the recast |
Please evaluate the new version of the article in the light of the changes made.
Reviewer 3 Report
There are many shallow saline lakes in Central Asia under arid steppe climate. Compared with fresh water lakes, the composition of zooplankton in these lakes is special. The authors investigated and analyzed the composition and diversity of zooplankton in saline Lake and gave new information about zooplankton in the studied area. Unfortunately, this paper lacks innovation and the readability is poor. Also, the English language needs to be revised. Considering the special compositions of zooplankton in saline lakes, I suggested that the authors reorganize this paper and resubmit it.
Author Response
Thank you for your comprehensive evaluation, comments.
Article title changed. New title:
Zooplankton community structure in shallow saline steppe inland waters
The novelty of the work lies in the fact that we conducted a study in a large-scale geographical region where data on the zooplankton population of shallow, steppe salt waters have not been available so far.
Our goal was to register the dominant as well as indicator organisms found in the rotifer and microcrustaea assemblages in these undisturbed, natural aquatic ecosystems. These results can serve as a basis for further survey of the area. As these include semistatic and summer-drying intermittent water bodies, only the spring aspect of the zooplankton community was measured by a single sampling, no temporal changes were made.
The article has been redrafted as suggested. We performed a detailed analysis of the quantitative and qualitative composition of rotifera and crustacea assemblage, as well as the dominant and indicator species.
Three groups of shallow inland saline waters were divided into characteristic groups based on the combined composition of zooplankton.
The English language has been revised Please evaluate the new version of the article in the light of the changes made.
Round 2
Reviewer 1 Report
I have no comments . The MS is well written.
Author Response
Answer for Reviewer Thank you for your review and evaluation. We are grateful to recommend the manuscript for publication. We have made some clarifications in the manuscript, which can be found in last modified version.
Reviewer 2 Report
Figure 6 needs to be improved visual. It's very difficult to read and discern anything usable from it. I'm also not sure its necessary. You basically just show everything is similar--maybe put this in the supplement if you think it's necessary.
Glad to see the PCA has been taken out.
Put the thesis statement into sentences? It's awkward and reads like a powerpoint slide as-is (lines 65-77).
Extensive review of English required. This needs a native speaker because most issues are grammar and diction. I am happy with the study and the new analyses, but the manuscript itself is still not sufficiently well-written to be published as is. I can understand what the authors are saying throughout, but the manuscript shouldn't have to be decoded so regularly throughout.
Author Response
Answer for reviewer
Thank you for your comprehensive evaluation and valuable comments and suggestions.
Answers and amendments to the comments are given below
| Evaluation, comments, old serial numbers |
Answer, changes, new line number |
|
Figure 6 needs to be improved visual. It's very difficult to read and discern anything usable from it. I'm also not sure its necessary. You basically just show everything is similar--maybe put this in the supplement if you think it's necessary. |
Thank you for your suggestion. Understanding and accepting its reasons, Figure 6. has been deleted
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Put the thesis statement into sentences? It's awkward and reads like a powerpoint slide as-is (lines 65-77). |
In our opinion, the communication of theses in this form is logical and clear. Therefore, only minimal change was applied. Lines 66-78. |
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Extensive review of English required. |
English language review was performed |
We have made some clarifications in the manuscript, which can be found in last modified version.Please evaluate the new version of the article in the light of the changes made.
Reviewer 3 Report
This paper has made a good revision according to the opinions. It can be accepted after minor revision.
Specific comments:
- Table 3, the significant level (0.05 or 0.01) should be showed.
- In Fig. 2, no significant level.
- In Fig. 5, the curve fitting of data should be done.
- P146, results should be changed into "Results and discussion".
Author Response
Answer for reviewer
Thank you for your comprehensive evaluation and valuable comments and suggestions.
Answers and amendments to the comments are given below
| Evaluation, comments, old serial numbers |
Answer, changes, new line number |
|
1. Table 3, the significant level (0.05 or 0.01) should be showed |
The significant level was indicated below Table 3. Line 184. |
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2. In Fig. 2, no significant level.
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Figure 2, has been modified.The significant level was indicated below Figure 2.Line195-198. |
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Figure 4, has been modified.The significant level was indicated below Figure 4.Line 226-229. |
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3. In Fig. 5, the curve fitting of data should be done. |
Figure 5, has been modified. Curve fitting of the data was performed, indicating the significant level. Line 252-255. |
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4. P146, results should be changed into "Results and discussion". |
The change “Results and discussion” has been made. Line 146. |
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Table 6. was changed, the previous version was missing a column.
Line 322-323 |
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Figure 6. has been deleted |
| English language and style are fine/minor spell check required |
English language review was performed |
We have made some clarifications in the manuscript, which can be found in last modified version.Please evaluate the new version of the article in the light of the changes made.
