Modeling of Water Quality in West Ukrainian Rivers Based on Fluctuating Asymmetry of the Fish Population

Round 1

Reviewer 1 Report (Previous Reviewer 2)

1.      Page 5: Please briefly describe the methodology of water sampling. What kinds of equipment you used in this sampling?

2.      Page 5: Water temperature is very sensitive for fish, especially for 3–4-month-old fish. Why did you choose these 13 hydro-chemical parameters? How about water temperature?

3.      Page 9: The Table 1 just shows water quality data in sampling site No. 6 of Ustya for four days. It is not enough to understand the characteristics of water quality in the study area. It is better to show the average values of water quality parameters for each site during the three months.

4.      Page 9: The most polluted river was the River Ustya. Why? Please explain it.

5.      Page 9: 3.2. Determination of the dominant fish populations in the studied rivers. Fishes were caught during between June and August 2021. Please describe the date and frequency of research fishing. Is it daily, weekly or monthly fishing? In the morning or afternoon?

6.      Page 11: Both in sampling site No. 1 and in sampling site No. 2, the highest FFA were in common roach. However, sampling site No. 3, the highest FFA were in common rudd; while in sampling site No. 5, the highest FFA were in common bleak. They are different from each other. Why? What is the most important reason?

7.      Page 14: In Table 11, ANN 4 model had the optimal results. The best values of MAPE and R2 were obtained at the 100th epoch and were equal to 6.7% and 0.97187, respectively. However, ANN 6 model also had wonderful results. The R2 was 0.97627 which was better than ANN 4. Why did you choose ANN 4?

Author Response

The authors sincerely thank the reviewer for their insightful comments. Our responses to comments in attachment file.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

Please refer to attached file.

Comments for author File: Comments.pdf

Author Response

The authors sincerely thank the reviewer for their insightful comments. Our responses to comments in attachment file.

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The general aims of the paper are:  

1)     Analysis of the fish species in the study area

2)     creating the model (ANN) for predicting water quality based on the FFA

 

The study lacks several introductory explanations, for example:

1)     What is WQI and how it is calculated? Please add more explanation on what is WQI in your paper, since the definition varies in different studies and can depend on different parameters.

2)     Is catching fish performed whenever samples of water are taken? Can FFA change within three months?

3)     ANN is not described properly or not modeled properly.

a.     Why have you chosen the presented structure of the ANN? It is said that it is optimal according to experiments. Which experiments? Which parameters did you try?

b.     You took the structure of ANN as it is and varied other parameters, that are not necessary to vary in a study like this. For example epochs…  

c.     How come the structure consists of 13 inputs and in the text, it is explained that 14 inputs are given (FFA missing maybe)?

d.     If the ANN takes 14 parameters then it is not a prediction of WQI from FFA (as it is claimed in the paper), but rather from chemicals and FFA. What is the benefit of the such model?

e.     Reporting ANN  - missing MSE and MAE introduced in the paper.

4)     There are too many numerical results, hard to read. Tables 3-10 should be presented more compactly – visually or numerically, with emphasized important results. Also missing p values in tables? Such tables can be put in Appendix.

 

 

Author Response

Dear reviewer, author's answer to comments in attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

 1.      Page 5: It is the same question for water sampling. It is very important to explain the sampling date and frequency of water quality survey. Please describe the sampling period. How long?

2.      Page 5: Why did you choose these 13 hydro-chemical parameters? How about water temperature?

3.      Page 9: The Table 1 just shows water quality data in sampling site No. 6 of Ustya for four days. It is not enough to understand the characteristics of water quality in the study area. It is better to show the average values of water quality parameters for each site during the three months.

4.      Page 9: The most polluted river was the River Ustya. Why? Please explain it.

5.      Page 9: 3.2. Determination of the dominant fish populations in the studied rivers. Fishes were caught during between June and August 2021. Please describe the date and frequency of research fishing. Is it daily, weekly or monthly fishing? In the morning or afternoon?

6.      Page 11: Both in sampling site No. 1 and in sampling site No. 2, the highest FFA were in common roach. However, sampling site No. 3, the highest FFA were in common rudd; while in sampling site No. 5, the highest FFA were in common bleak. They are different from each other. Why? What is the most important reason?

7.      Page 14: In Table 11, ANN 4 model had the optimal results. The best values of MAPE and R2 were obtained at the 100th epoch and were equal to 6.7% and 0.97187, respectively. However, ANN 6 model also had wonderful results. The R2 was 0.97627 which was better than ANN 4. Why did you choose ANN 4?

Author Response

Dear reviewer, author's answer to comments in attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Despite my previous comments, the manuscript is not revised properly. I was hoping that the authors' review will clarify some doubts. According to the authors' reply, I can only conclude that the modeling is not done appropriately.  

Modeling the water quality is the main contribution of the paper. Therefore, I will not repeat myself with the comments from the last review. I will rather emphasize the main drawbacks of modeling presented in the paper.

1. The ground truth (the water quality which is believed to be the truth, according to which the model is evaluated) is not explained. I can only assume that the quality is calculated (by usual monitoring) from 13 chemicals.

2. The model which takes all 13 chemicals and adds one more input parameter (measures of the fish) doesn't make the sense. If we can calculate quality from 13 parameters, why would we like to put a lot of effort into catching much fish, measuring a lot of parameters of the fish, and calculating FFA to end up with the model which takes 14 parameters and performs worse that the initial formula? The model should take only FFA or measures that FFA consists of as input parameters. Still, I would doubt the usefulness of the model, since I believe that measuring chemicals is easier than catching and measuring fish to estimate water quality.