A Study on the Characteristics of Fishery Resources Distribution in Coastal Waters of Yeongil Bay Using Acoustic Survey

Round 1

Reviewer 1 Report

A very important and relevant work. Please make the necessary minor corrections shown in the revised pdf.

Comments for author File: Comments.pdf

Author Response

Thank you for your careful review of the paper.

Please see the attachment 

Author Response File: Author Response.docx

Reviewer 2 Report

Efficient management of fishery resources is of paramount importance for the economy of worldwide coastal areas. In this context, the identification of the fish stocks is crucial to assess spatio-temporal distribution of each fish species. In this paper the authors propose a hydroacoustic survey based on acoustic data to identify the presence of marine organisms. The paper is well written and the idea to support the management of fishery resources is worthy of attention. The overall scientific soundness of the paper is fair. The proposed hypothesis, methods and discussions are robust and consistent enough. However, the structure of the manuscript must be revised before being accepted for publication:

• the target is not clearly stated in the introduction. Please provide more information concerning issues and consequences of wrong assessment of fish stocks;
• discussion on the limits of the proposed methodology appears to be not exhaustive, since a more in-depth analysis, should be performed;
• conclusions are missing (again, the target must be reported also in this section);
• the paper would finally benefit from a thorough English proofreading.

Author Response

Thank you for your careful review of the paper.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Overview:

In this study, the identification of dominant fish species in the East Sea was conducted using the dB-difference method. The survey was conducted using the two frequencies of 38, 120 14 kHz in transects 6 of the southern part of the East Sea. Information on fish species was identified 15 using fishing gear and e-DNA.

The area of expertise of this reviewer is in acoustics but not in the field of this publication. Having this as a given, this reviewer failed to understand the innovation of this publication. The authors fail to inform what the significance of this publication is. A better presentation of relevant publications as well as a comparison with older results may have been helpful.

Lines 47-49: ‘Among the techniques of hydro-acoustic survey, dB-difference method is actively utilized as a tool for evaluating the density and biomass of the target organisms as the method identifies fish species by difference in frequency characteristics’. Authors need to present more about the method.

The introduction is particularly weak. The authors do not present alternative methods, nor why this method was chosen.

Figure 1 should be in a vector format.

Lines 84-89: ‘When the frequency difference for each fish species has been clearly identified, a data range bitmap is created by setting the range of the frequency values, and a mask is created with the echo set in this range and the echo matching the cell size of the frequency 38 kHz, and this is then divided by the ping interval, and the echo matches with the echo of 38kHz with noise removed is considered as the echo of the applicable fish species’. This sentence needs restructuring.

Lines 89-91: ‘Using the above method and procedure, each species can be identified by separating the echoes of the respective fish species suitable for the characteristics’. It is not clear what the exact application of the method is. Better presentation of the method would be useful (using more math).

Figure 2 should be in a vector format.

Table 2 must be presented differently (smaller size).

Lines 99-100: References are needed.

Line 148: Equation should not be presented in a graph form.

Lines 217-229: References should be included

(e.g. The results of previous studies (?) on the distribution of fish species by water depth showed that Engraulis japonicus shoal was mainly distributed at a depth range of 12 m…….. )

Author Response

Thank you for your careful review of the paper.

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors have revised the Paper to meet the main requests for change and the suggestions I recommended.
I feel that the review process led to an improved manuscript, and I suggest the acceptance of the paper for publication in Applied Science.Overall, the linguistic component of the paper is good, even if some parts require minor improvements.

Sincerely yours,

Reviewer 3 Report

Dear authors, I am afraid that the conclusions of my initial review still apply. In my initial review, a better presentation of the alternative methods was asked something that was not done. Also a better presentation of the methodology was asked. Instead a reference to a software manual was provided, something that is not adequate.  I believe this paper unfortunately is not ready to be published to the prestigious Applied Sciences journal.