Neo- and Paleo-Limnological Studies on Diatom and Cladoceran Communities of Subsidence Ponds Affected by Mine Waters (S. Poland)

Round 1

Reviewer 1 Report

The paper is good and should be published in the journal. Methods of sampling, processing of samples, statistic analysis are adequate and well-conducted. Discussion is adequate and conclusions are sound. Combination of paleolimnological methods with study of existing planktonic community allow authors to clearly describe process of community changes after the end of active pollution. The paper, in my opinion, will be valuable for wide range of paleolimnologists and hydrobiologists dealing with pollution and recovery of water bodies.

I have only onу significant comment 

Authors took samples of Cladocera from the water column central point of the ponds only. Such sampling can lead to potential bias in form of under-sampling of substrate-associated cladocera – but it is aссeptable if pond is shallow and owergrown. The reasons for choosing such type of sampling should be clarified in Material and Methods.  This also can be a reason for higher diversity of Chydoridae in sediments.

In discussion, author state “Generally, planktonic Cladocera were a more differentiated group (5 family and 13 taxa) than in sediment (3 families and 15 taxa).” This result can be attained because subfossils of species of Daphnidae and  Moinidae are frequently poorly preserved  in sediments, the only well-preserved part is ephippium of gamogenetic females, which can be rather rare. And some less common Chydoridae can be absent from plankton species list samples because substrate-associated cladocera were not specifically sampled.   

Also, there are some minor remarks.

At lines 393-394 authors wrote “Chydorus sphaericus  negatively correlated with all heavy metals, but Alona affinis and A.quadrangularis positively correlated with Pb.”, but in Table 7 and Figure 5 these correlations are negative.

In figure 3, RXII one of the species is Alona excisa – this species is Alonella, not Alona.

Alona rectangula presently transferred to the genus Coronatella - see the following paper

Van Damme, K. & Dumont, H.J. (2008a) Further division of Alona Baird, 1843: separation and position of Coronatella Dybowski & Grochowski and Ovalona gen.n. (Crustacea: Cladocera). Zootaxa, 1960, 1–44.

Author Response

Reviewer 1

 

1.  

Answer:

Authors would like to thank Reviewer for the essential comments which improve manuscript.

2.

„I have only onу significant comment. Authors took samples of Cladocera from the water column central point of the ponds only. Such sampling can lead to potential bias in form of under-sampling of substrate-associated cladocera – but it is aссeptable if pond is shallow and owergrown. The reasons for choosing such type of sampling should be clarified in Material and Methods.  This also can be a reason for higher diversity of Chydoridae in sediments.

In discussion, author state “Generally, planktonic Cladocera were a more differentiated group (5 family and 13 taxa) than in sediment (3 families and 15 taxa).” This result can be attained because subfossils of species of Daphnidae and  Moinidae are frequently poorly preserved  in sediments, the only well-preserved part is ephippium of gamogenetic females, which can be rather rare. And some less common Chydoridae can be absent from plankton species list samples because substrate-associated cladocera were not specifically sampled.”

 Answer:

In Material and Methods we added information about a physical characteristics of the ponds e.g. depths and areas and describe sampling area.

 

We agree with the Reviewer's opinion on comments on Cladocera taxa results in plankton and sediments. The authors actually wanted to confirm how many taxa were found in water and sediments, despite some limitations resulting from the methodology and research. The studied reservoirs were homogeneous, shallow and covered with macrophytes, with a similar area.

 3.

„Also, there are some minor remarks.

1. At lines 393-394 authors wrote “Chydorus sphaericus  negatively correlated with all heavy metals, but Alona affinis and A.quadrangularis positively correlated with Pb.”, but in Table 7 and Figure 5 these correlations are negative.
2. In figure 3, RXII one of the species is Alona excisa – this species is Alonella, not Alona.
3. Alona rectangula presently transferred to the genus Coronatella - see the following paper”

Answer:

All minor remarks were improved:

1. We changed word positively on negatively. It was our mistake.
2. It was our mistake. We changed name Alona excisa on correct name Alonella excisa.
3. The name of Alona rectangula is changed on Coronatella rectangula in the text, tables and figures.

 

 

Reviewer 2 Report

Reviewer comments: Manuscript Number: Water-791062

Title:  Neo- and paleo - limnological studies on diatom and cladoceran communities of subsidence ponds affected by mine waters (S. Poland)

Overall impression:  Despite the well-executed field work there are important questions that need answering: why it is assumed that the comparison is between the three DOWN ponds are an UP pond (most recent after mining cessation in 2009). Other important questions, how the authors can discriminate the impact of urban inflow from previous mining? These topics are mentioned in the discussion but are not mentioned in the introduction appearing as a new insight from the authors which should be presented in the introduction. Please find a detailed issues that need addressing.

Abstract: Gives an insight of what the research is about.

Aim: Clear, concise and informative

Keywords: appropriate

Introduction: Clear and easy to follow.

Methods/Model: Please provide physical characteristics of the pond e.g. depths and areas. Describe sampling area e.g. macrophyte presence, colouration etc.  turbidity.

Line 98 – Please undisclosed what is WTW.

Line 114 – Please revise this sentence, how could you collect 10 litres of water with a 10 µm plankton net?

Line 115 – how close, please provide an approximate figure of the proximity.

Line 124- correct 0,2% to 0.2%

Lines 131-132 Please explain why this is. Is it due to slope? Depth? Wind direction?

Line 149- Please explain what is and what does and why are you using the Wald-Wolfowitz instead of other more conventional tests to find significant differences of the physicochemical variables.

Lines 166-178 Please correct, this paragraph is of different font size.

Line 189 – incomplete sentence, While Cl- - when compared to those at sites CH1, CH4 and CH5. It does not make sense.

Line 211- Table 1. Please indicate if the values are mean, median, SE or SD. These variables should be presented as medians with a range of min and max values.

Please explain what the test

Results: A clumped information without a narrative that tires the reader. It does not flow.  

• The results need to be organized in a way that is easier to follow.
• Table presentations need to improve in a more simple and clear manner, less lines perhaps?
• Tables with physicochemical variables need to indicate the measure of dispersion used e.g. median, mean, SE, or SD; the reader does not know. It is advisable for this type of results to provide the range of the values (min and max values.

Discussion Please provide signposts for the reader in the discussion as in the results. It is confusing and difficult to read. However, the discussion seems to be a more readable version of the results. It relies excessively on the data which made feel the reader be reading again the results.

In the end the reader does not have a clear idea of the relevance of the diatom and cladoceran taxa found. The discourse is lost and is not consistent with the introduction.

Author Response

Reviewer  2

 

1.

Answer:

Authors would like to thank the Reviewer for the essential comments which improve manuscript.

 

2.

” Overall impression:  Despite the well-executed field work there are important questions that need answering: why it is assumed that the comparison is between the three DOWN ponds are an UP pond (most recent after mining cessation in 2009). Other important questions, how the authors can discriminate the impact of urban inflow from previous mining? These topics are mentioned in the discussion but are not mentioned in the introduction appearing as a new insight from the authors which should be presented in the introduction. Please find a detailed issues that need addressing.”

Answer:

The authors added sentences to the Introduction (line: 70-73), Material and Methods (line: 86-88; 90-92), as well as to the Disscusion (line: 634-639) to make the article more readable.

 

3.

„Methods/Model: Please provide physical characteristics of the pond e.g. depths and areas. Describe sampling area e.g. macrophyte presence, colouration etc.  turbidity.”

Answer:

In Material and Methods we added information about a physical characteristics of the pond and described the sampling area (line: 90-92).

 

4.

„Line 98 – Please undisclosed what is WTW.”

Answer:

Remark is improved (line: 109).

 

„Line 114 – Please revise this sentence, how could you collect 10 litres of water with a 10 µm plankton net?”

Answer:

10 µm plankton net is a widely recommended method used for diatoms analyses.

 

„Line 115 – how close, please provide an approximate figure of the proximity.”

Answer:

The recent samples and subfossil samples were taken from the same localities (line: 126).

 

„Line 124- correct 0,2% to 0.2%”

Answer:

Corrected.

 

„Lines 131-132 Please explain why this is. Is it due to slope? Depth? Wind direction?”

Answer:

The sentence is corrected (line: 142-143)

 

„Line 149- Please explain what is and what does and why are you using the Wald-Wolfowitz instead of other more conventional tests to find significant differences of the physicochemical variables.”

Answer:

Wald-Wolfowitz test allows comparison of groups with a small number of samples (minimum 4), while other non-parametric tests require samples with more record. The samples of water were taken four times a year (April, July, September and October 2016). Therefore, to find significant differences in the values of the studied physicochemical va riables in water between the examined sites (CH1-CH5) the Wald-Wolfowitz test was chosen.

However, to simplify the table and text, instead of differences between individual ponds, we provided differences in the physico-chemical parameters of water between the UP and DOWN ponds (New Table 2). For this aim we use the Mann-Whitney test (line:159-160).

 

„Lines 166-178 Please correct, this paragraph is of different font size.”

Answer:

We  unified the whole text in terms of font size and type.

 

„Line 189 – incomplete sentence, While Cl- - when compared to those at sites CH1, CH4 and CH5. It does not make sense.”

Answer:

We changed the paragraph and this sentence (line:197-206).

 

„Line 211- Table 1. Please indicate if the values are mean, median, SE or SD. These variables should be presented as medians with a range of min and max values.”

Answer:

We changed  Table 1 and added medians with a range of min and max values.

 

5.

 

„Please explain what the test

Results: A clumped information without a narrative that tires the reader. It does not flow.  

• The results need to be organized in a way that is easier to follow.
• Table presentations need to improve in a more simple and clear manner, less lines perhaps?
• Tables with physicochemical variables need to indicate the measure of dispersion used e.g. median, mean, SE, or SD; the reader does not know. It is advisable for this type of results to provide the range of the values (min and max values.

Discussion Please provide signposts for the reader in the discussion as in the results. It is confusing and difficult to read. However, the discussion seems to be a more readable version of the results. It relies excessively on the data which made feel the reader be reading again the results.

In the end the reader does not have a clear idea of the relevance of the diatom and cladoceran taxa found. The discourse is lost and is not consistent with the introduction.”

 

Answer:

 

All the above remarks are improved in the text and tables.

 

Round 2

Reviewer 2 Report

I would like to thank the authors for taking in the recommendations, I agree the paper has improved tremendously, particularly the presentation of results. It is now inviting for reading and appreciate the work conducted by the authors.

Lines 217-218 - Just a minor thing is that there is an empty table prior to Table 1 which I believe might be an editing error.

There are also a couple of large empty spaces (blank pages) which I assume will resume in the final version for publication.

Author Response

I would like to thank the Reviewer for finding minor mistakes. We improved it and tried to minimize the empty space (empty pages).
We also improved the font in line 163-167 and moved the text from line 292-299 to line 281-289.