Ecological Potential of Freshwater Dam Reservoirs Based on Fish Index, First Evaluation in Poland

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

All to do the manuscript it is good and well written But there are certain points which I need to mention here for the authors:

1. The study is very important for the ecological and freshwater conservation but I do not know how till date no study has been conducted as in the title it is written this is the first study

2. Authors Should remove first study from the title

3. Abstract need to show how this study will contribute in river conservation in one line

4. Introduction needed to be updated with mentioning why this lever water is not yet been studied or ignored

5.  Author should define a comparison with other rivers in the region

6. Conclusions should be mentioned with The importance of study and future prospects and recommendations after conducting the study

Comments on the Quality of English Language

enlgish is fine

Author Response

Comments 1.

1. Assessment for dam reservoirs for other ecosystem components is already underway. However, it has never been made for fish in Poland. This is a study commissioned by the Polish Government, which also used the statement in the project itself that it was the first.
2. Maintaining answer no. 1, we do not see the need to change the title, because it is consistent with the order for these studies by the Polish Government.
3. The indicators quoted in the introduction also correspond to rivers. One sentence will be added about the reference to rivers.  
4. Dam reservoirs have not been tested for ichthyofauna for a very prosaic reason: lack of financial resources. We do not intend to add this information.
5. This is a very interesting proposition and we have actually made such a comparison and it is often consistent with our results, but we have not found any such studies in the literature on the subject where such comparisons have been made. We are actually considering enlarging the discussion section. However, the article focuses on one method and goal and we are considering expanding the provisions. After making these changes, we will decide if the article will be consistent.
6. Such thoughts and proposals will be added for further monitoring.

Reviewer 2 Report

Comments and Suggestions for Authors

Review's comments on " Ecological potential of freshwater dam reservoirs based on Fish Index, first evaluation in Poland".

The author systematically developed an ichthyological indicator to assess the ecological potential of freshwater dam reservoirs in Poland. It is a significant and wonderful work to help us to understand the situation of eutrophication in Poland. However, some poor organization prevent readers to understand fully the findings of this study.

Major comments:

You mentioned TSI index, please specific How to get the TSI index? You should describe in Material and Method section.

Lines 51-56 you just simply listed many ichthyological indicators? What’s differences and discrepancy in these indicators? Brief introduce them.

Lines 81-99 The rules of characterized state of ichthyological indicators should be listed in Material and Method section, not in Introduction section.

Lines 195-239 Just briefly describe you used method to determine the correlation between the ichthyofauna and the selected pressure indicator. Too much background in these sections.

Lines 289-290 The figure is low quality.

Lines 368-369 The figure is low quality.

Line 340 How to unify these parameters eg. Tool type, factor specification?

Line 357 Whether to consider the independence of the two parameters when choosing combined?

How to choose not based on water quality indicator? What screening rules may take into consideration?

How to reduce the uncertainty of each indicator?

You mentioned fishing tools and techniques also effected the fish data (species, numbers) collection? Maybe improve the useful data for evaluation. How to the differences caused by fishing tools?

Minor comments:

Line 34: is not are

Line 137: add unit in Distance from source

Keep units consistently, you sometime used μgl-1 in Line 76, some time used mg/L in Line 169

Line 254: add units (m) in Secchi dis depth

Line 295: Keep valid values (R value) ​​consistent

Line 309, what means r>2?

Line 385 Pay attention to uppercase and lowercase

Comments on the Quality of English Language

Some format and spelling errors need be corrected.

Author Response

Comments 2

1. TSI index will be described.
2. The cited indicators will be briefly discussed.
3. The article focuses strongly on the method of performing such analyses. Therefore, the introduction of the article contains general explanations that guided the selection of the appropriate method used. There are also many references to methods in the discussion. According to the authors, this approach is consistent.
4. In identifying the topic, the types of correlations were explained in detail in the most important cited articles. It seems very important to us to show exactly what correlations were carried out and which ones were not. In the subsequent parts of the article, we also refer to the contextual correlations mentioned here.
5. Resolution will be corrected.
6. Resolution will be corrected.
7. We don't understand the question.
8. The association of these two parameters in their relationship has been selected in the master plan in order to make easy interpretation. However, mathematically this can be done separately as indicated. Various ichthyological indicators also often combine abundance and biomass with information about the type of fish and origin (invasive or alien or native species). We believe that many different paths lead to the correct formulation of the assessment. However, our intention was to simplify the result as much as possible, but using a very specific method of collecting the samples.
9. Fishing tools and technique are by far the most important in fish sampling. We have tried to explain this broadly. Further stages of work on this indicator will involve improving these methods. Thank you for this question and in conclusion we will increase the emphasis on further needs in research and greater attention to precision in collection methods.

Minor comments: All comments will be implemented.