Enhancing Chub Mackerel Catch Per Unit Effort (CPUE) Standardization through High-Resolution Analysis of Korean Large Purse Seine Catch and Effort Using AIS Data

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I have read and reviewed the paper entitled ‘Enhancing Chub Mackerel Catch Per Unit Effort (CPUE) Standardization through High-Resolution Analysis of Korean Large Purse Seine Catch and Effort Using AIS Data’. This paper performs well in terms of figures, but the logic of the article is not rigorous enough, and many contents lack specific introductions. So there is still a lot of work needs to be done to publish the written expression. Some technical issues also need to be clarified. The specific issues are as follows：

 

1.The introduction should clearly explain the research background and the main purpose of this study? Generally, at the end of the introduction, you should clearly emphasize your research motivation as much as possible. The introduction is very long without a clear structure, and not convincing when it explains the research problem justifying the need of this study. It is not interesting for the reader.

 

2.The second part of the manuscript conducted a systematic model construction, and the argumentation process was very rigorous. However, there seems to be some ambiguity in the presentation of the research results, which requires further adjustment and modification.

For example，About data sources: What is the data source used in the article and what is the scope of calculation?

 

3. There are many problems in the author's overall language expression. It is suggested that the author should make more use of scientific and technological language to express the conclusion and improve the accuracy of the article. The citation format of the article's references is not unified. The references should be proofread and modified according to the requirements of the Journal.

 

4.The article lacks the section of conclusion, and what is the significance of this study for other countries. There are still unresolved issues that have not been discussed. The conclusion should highlight the research focus, what problems the article has solved, why the research content is important, what theoretical basis it has provided, what value it has achieved, and what help it has given to decision makers, rather than general suggestions.

 

In overall, I suggest a major overhaul of the paper, otherwise it is not recommended for publication

Comments on the Quality of English Language

I have read and reviewed the paper entitled ‘Enhancing Chub Mackerel Catch Per Unit Effort (CPUE) Standardization through High-Resolution Analysis of Korean Large Purse Seine Catch and Effort Using AIS Data’. This paper performs well in terms of figures, but the logic of the article is not rigorous enough, and many contents lack specific introductions. So there is still a lot of work needs to be done to publish the written expression. Some technical issues also need to be clarified. The specific issues are as follows：

 

1.The introduction should clearly explain the research background and the main purpose of this study? Generally, at the end of the introduction, you should clearly emphasize your research motivation as much as possible. The introduction is very long without a clear structure, and not convincing when it explains the research problem justifying the need of this study. It is not interesting for the reader.

 

2.The second part of the manuscript conducted a systematic model construction, and the argumentation process was very rigorous. However, there seems to be some ambiguity in the presentation of the research results, which requires further adjustment and modification.

For example，About data sources: What is the data source used in the article and what is the scope of calculation?

 

3. There are many problems in the author's overall language expression. It is suggested that the author should make more use of scientific and technological language to express the conclusion and improve the accuracy of the article. The citation format of the article's references is not unified. The references should be proofread and modified according to the requirements of the Journal.

 

4.The article lacks the section of conclusion, and what is the significance of this study for other countries. There are still unresolved issues that have not been discussed. The conclusion should highlight the research focus, what problems the article has solved, why the research content is important, what theoretical basis it has provided, what value it has achieved, and what help it has given to decision makers, rather than general suggestions.

 

In overall, I suggest a major overhaul of the paper, otherwise it is not recommended for publication

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript attempts to apply vessel movement and tracking data, combined with logbook and fisheries data to provide a more refined and informative evaluation of chub mackerel stocks using CPUE data. The approach and application could prove valuable to the large purse seine fishery in Korea.

 

 

General Comments:

 - The weighted distribution methodology used to value the temporal aspect of catch (Lines 218-235) assumes a directly proportional increase between catch and fishing segment length. However, there is no citation to provide any justification for this assumption, and it is just as logical to believe that segments may be fished longer if catch is low. Thus, the interpolation of the is relatively arbitrary and I'm not sure that it can be said to have "ensured a comprehensive and just allocation of catches across the array of segments". The authors do mention that catch rates can influence handling times (Lines 84-85), but mention this can vary widely and that that relationship is still unknown (Line 86). Without having some information/citation about how this relationship may progress, I can't say that the weighted distribution method actually helps fill any knowledge gap.

 - There are several questions/issues that could be raised with the modeling portion of this study. In particular, the lack of interactions in the model (which are later mentioned, indirectly, to be of importance) and the complete separation of month and year data.

       - The paper talks extensively about the "complex" nature of the system and all of the interplay that occurs to determine when and where chub mackerel will be located; however, the models include only main effects when certain interactions seem to be crucial. For instance, the interaction of SST and SSS likely plays an important role in the taxa that may be in an area (this also likely differs between regions). Similarly, those changes are going to change seasonally, further expressing the importance of their interplay. During your explanation of the GLM/GAM background information (and in the Discussion), there is considerable discussion about GAM's ability to model nonlinear relationships and interactions, but the latter is completely excluded from all models.

        - Only treating "year" and "month" as completely separate variables severely limits the models' usefulness. Month is inherently nested within a given year, and months are not necessarily similar between years (as mentioned in passing for Lines 480-483).

 - There are several inconsistencies such as "chub" being capitalized when no needed, and several missing/incorrect punctuations throughout. I have not marked or correct them, but a read-through to correct these items is needed.

 - Table and Figure captions are, in general, lacking important information. Table captions do not specify whether they are for nominal or standardized CPUE models. Also, not units are provided the for variables. Figure Captions provide no detailed information about what the plots are showing (see more in specific comments).

 

Specific Comments:

[Line 44] remove "to fisheries management"

[Line 71] remove "Studies"

[Line 140] what the units for the salinities?

[Line 149] what is "EEZ", this has not been defined

[Line 212] Figures are referred to as "A" and "B" in the caption and should be labeled as such. Additionally, it is unclear what is being shown here. In Fig. 1A, is this the entire fishing grounds? What does the markings indicate - is that the path for just one ship/trip? In Fig. 1B, what do the colors of the points mean - if that is speed, then why are some of the other slow portions (presumed based on the red/orange color) marked as "fishing segments". Also, please provide coordinates for the two figures so the reader can better understand the spatial extent. Overall, this figure is not very informative and needs attention to explain what all is being shown. Different portions of the surrounding waters should also be labeled to explain where the different fishing regions are located.

[Lines 218-235] As stated in the general comments, this portion of the methods needs some form of justification. If other CPUE studies have used this approach to provide per haul estimates then cite them, or if studies have shown that increased haul segment lengths equates to proportionally increasing catch. But without a justification for this method I fail to see the usefulness of arbitrarily assigning a proportionally increasing catch to increased haul length.

[Line 237] Redefine the SST and SSS variables here (only done in the abstract). Also, include units for the variables in [Lines 237-238].

[Line 257] provide the citation for the "mgcv" package in R since this is a third party package.

[Lines 262-268] I'm not completely sure why CPUE data was log-transformed before inclusion in the GLM. GLMs are specifically designed to handle non-normal data types (hence the family/link functions). Transforming the data prior to GLM analysis seems like an unnecessary step. If transforming was important, why not simply transform the data and use a regular linear model? Some additional information for the transformation decision may be useful.

[Lines 266-268] The fact that "there were no zero values" is an issue that needs to addressed. Having no zero values will lead to an overestimate of the CPUE. I realize that you are limited by the data available to you, but this potential source of error in the CPUE should be explicitly detailed.

[Line279] include citation "33" for the sentence ending in this line.

[Line 299-300, 302-303, 303-305, 310-312] Delete all of these sentences, they are all nearly identical restatements of the information provided in the first paragraph of the this section (2.6).

[Line 329] change "was" to "were", and "indicated" to "indicating"

[Line 331] remove the "3" at the end of the sentence.

[Line 337] The 35% does not match Table 1 where it seems that Month only accounted for ~24% of the variation. If you got 35% from somewhere else, please explain.

[Line 341] "Table 3" should be changed to "Table 2"

[Line 343] According to the Table, Month and Year only accounted for 45% of variation, not 47%, and the remaining variables accounted for 7%.

[Line 364] The p-value has an extra "0" compared to everything on the table. Is this p-value from a global test? If so, information from the global test should be provided somewhere within the text or tables.

[Line 378-380] the mention of the "density of points" is misused here. The density of points does not provide any information on the "effect of depth on CPUE". The known range of chub mackerel is discussed in the introduction and listed as 10-100m, and that is where the vast majority of the seines were fished. This not provide information on the "effect of depth"; this only tells you that nearly all of your data came from those depths.

[Line 393] Should "2022" be changed to "2021"?

[Lines 395-397] You state the fishing is closed April-June and you have no catch data for that portion of the year, but you still included those months in the dataset. How are you incorporating that data? Where is it coming from? What does it mean? It is probably better to treat July as "month 1" and run the figure/model from July - March.

[Lines 410-412] The indices are not "explaining" any peaks. Yes, there are peaks there, but the model is not explaining that, it is simply providing that estimate. It is up to you to explain that using the data/fishery information you have.

[Line 415] The models differed from the GLM between Feb-Aug. This is 3/4 of the year, and includes the "closed" period. What can you actually say about this difference? More explanation/discussion is needed to provide some context of importance here.

[Line 415-418] delete these 2 sentences, they are restatements of information already provided.

[Line 418] Again, the model is not "explain[ing] the peak", it is just showing one.

[Lines 419-420] You say that they differed, but provided no statistical evidence of it. The confidence bands appear to be overlapping, and do not look to be higher/lower than anything else across most of the timeframe. If they are different, then statistics need to be provided.

[Lines 424-432] Plots should be labeled as A/B for Figures 4 and 5. Why no confidence bands on the Figure 5A? Inclusion of months 4-6 (Apr-June) still makes no sense as there is no fishing during this period, so it is unclear where the data comes from other than an interpolation by the models, but there is no information on the process for this interpolation.

[Lines 454-457] You models completely ignore interactions of different variables, so I'm not sure you can claim it provides "comprehensive coverage of potential relationships".

[Line 460] Again, p-value is an order of magnitude lower than anything provided in tables. Results from any global tests need to be provided.

[Lines 484-486] Here you mention changes in environmental factors across time (which suggests an interaction). To this point, you have provided no information/discussion/results on the changes of factors over time, so you can not claim that the changes in CPUE across years is due to changes in environmental changes.

[Lines 486-489] Remove this sentence, it provides no useful information. Yes, banning fishing for a portion of the year is going to stopping CPUE, but that doesn't really show the "link between regulatory measures and fishery performance" because there is no "fishery performance" during that time.

[Lines 489-491] The post-ban catch MIGHT be due to increased fishing pressure, but you provide no information in your study to corroborate that claim. Did you see an increased number of fishing vessels, or longer fishing trips following the ban period? Maybe it is simply an increase in fish density as this would be the post-spawning period also, which may suggest a congregation of chub mackerel in specific areas. Increased fishing pressure would have to be an increase in effort, but that information is not provided anywhere in the manuscript. This part of the "ban season" COULD show the link between policy and fishery effects, but you have to present that information if you want to make that claim.

[Line 498] Should that be 125, instead of 12.5?

[Line 499] remove "high" before "chub mackerel"

[Lines 499-502] split this into 2 sentences. It is very difficult to follow when written as one.

[Line 500] "2009" should be in parentheses

[Line 502] Remove "However" and start the sentence with "Optimal"

[Lines 510-512] This is the same information as the previous sentence, remove it and move citation "18" to be included in the previous sentence

[Line 513] You have no defined "Yellow Sea" as "YS" yet.

[Line 537] italicize the scientific name for S. japonicus

[Line 544] remove the extra bracket around [56-69]

[Line 563-564] This sentence is very confusing. The zooplankton are the food for the fish larvae and juveniles, so I'm confused how their peak abundance is synchronized with high food concentrations for the fish. I'm assuming this is just a simple grammatical mistake, but I think the sentence needs to be rewritten or removed.

[Lines 571-573] You talk about diurnal movement patterns, but then reference/cite seasonal patterns?

[Lines 577-580] This sentence, again, suggests that you looked at interactions of depth and temperature, but you provide no information/results on this within the text. If you investigated this relationship, it needs to be provided in the results. Otherwise, you can not discuss it here as if is part of the study.

[Line 538] italicize scientific name for E. japonicus

[Line 595] potential missing word in "connection cold bottom". I think it was supposed to say "connection with cold bottom", but I'm not sure. Revise as needed.

[Line 598] change "which" to "and"

[Line 601] remove the word "Celsius"

 

Overall, I think this manuscript has real potential and the inclusion of spatial and temporal data provide a great avenue to bolster CPUE estimates for this and other industries. There are several important issues that need to be addressed within the manuscript, but most are fairly simple fixes.

Comments on the Quality of English Language

Overall, the quality of English in the manuscript is fine. A few minor edits to addressed add/unnecessary words or to fix improper tense use is needed. But, again, these are minor and most will be caught by a thorough read-through by someone well-versed in the English language.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Using fishing vessel trajectory data to quantify fishing effort, calculate high resolution CPUE information, and standardize CPUE is veru importance for fisheries resource assessment, and there are already some papers on this topic. While this work is significant, but there isn't much innovation in this paper. The impact of the marine environment on CPUE has already been addressed in existing standardized articles.

The impression I get from this article, which calculates CPUE using AIS data and standardizes it, is that it is similar to articles that directly use fisheries data for CPUE standardization. However, the author claims that using AIS data accurately determines fishing effort, improves CPUE estimation, and enhances precise spatial management.

So I don't understand the research objectives and significance of this article, specifically how the spatiotemporal high-precision CPUE calculated in this paper improves spatial fisheries management. I also haven't seen the advantages of the CPUE calculated in this paper over traditional methods in fisheries management. If the environmental impacts obtained in this paper are similar to traditional methods, what is the significance of doing so?

My understanding is that what I expected to see is the difference between CPUE calculated with AIS and CPUE calculated without AIS, perhaps even including the differences after standardization.

Based on the points mentioned above, I feel that this article needs to be restructured.

Comments on the Quality of English Language

/

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

the paper provides an intersecting new approach to assessing chub mackerel catch. The text of the paper is robust and thoroughly describes each of the sections/chapters required by a scientific publication. However, in some points, clarity and formatting might be improved, which can be done in the following parts:

1. The introduction is a bit too long and could be shortened to fit to at most one and a half page. Additionally, for the last paragraph, I propose enumerating the aims of the paper rather than summarizing what has already been done (lines 121-130). Lines 131-133 could be moved either to the Discussion chapter or to the Conclusion.
2. Please unify the writing chub mackerel in the text, since in the text can be found “Chub mackerel” and “chub mackerel”.
3. As for the Study area – I believe that it would be interesting for readers to know more details about the area of concern. Therefore, I propose providing data about the size of the study area and a map delineating the area. I understand that Figure 1 is representing also the area, but I believe that this map with a trajectory of a vessel might be also kept in the text.
4. Line 206: Figure 1 (Line 2018) could be moved below the text under line 206, since there is a lot of space. Please check the instructions if it is allowed to provide a smaller figure. The main point of the figure is the trajectory of the vassal and the point will not be omitted by diminishing it.
5. Tables 1 and 2: Please check the size of the font of the captions of the tables’ titles it seems to be bigger than the rest of the text.
6. The Discussion chapter is too long I propose condensing it to up to 2 pages. All relevant points are presented, but the abundance of details makes it difficult to follow.
7. It seems that the Conclusion is an extended Discussion since numerous references are included. I propose to make the conclusion more concrete, i.e. to point out the main results and conclusions arising from the paper itself and eventually to emphasize novelties and advantages in comparison to some former practices.
8. Numbers in front of some references are wrongly written, e.g. line 803 and line 882. Please correct this.

 

 

Comments on the Quality of English Language

Dear authors,

I have not detected significant mistakes in English language within the paper, but I propose to be checked by a native English translator.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript has been improved. I accept the modifications made by the authors and agree to its publication.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf