Larval Fish Assemblages in Coastal Waters of Bangladesh: Spatial and Seasonal Dynamics

Round 1

Reviewer 1 Report

Journal：Conservation

Title: Larval fish assemblages in coastal waters of Bangladesh

Comments: This study established the baseline of the richness and evenness of fish larvae in the coastal waters of Bangladesh using bongo net for two-year sampling. The results indicated that Clupeidae and Engraulidae were the predominant. The environmental factors including water temperature, pH, salinity, and DO significantly impact the abundance of fish larvae. The surveillance design is interesting, and the obtained data can promote the development on the fishery resource management in bay of Bangle. There are some minor comments as below:

1.    Abstract: The parameters of the different environmental variables correlated with the abundance of the fish larvae in different area and time points should be showed as absolute values. As such, the readers can directly understand the correlations.

2.    Introduction: Its better to review the primary fish species in the coastal water and Bangladesh reported by previous studies in this section.

3.    Figure 3: Please detailedly portrait the characteristics of the fish showed in this figure, which meet the criteria proposed in the guidelines (Ref: 17, 29, and 30).

The English language of this manuscript is good.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

English must be improved. Discussion should be re-written. Comments on the attached copy

Comments for author File: Comments.pdf

As above

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The Authors carried out an interesting project and collected valuable data. Right away a technical remark: the towing speed declared by the Authors (2 km/10 min ≈ 6 knots) exceeded that recommended for a bongo-net (up to 4 knots). Some explanation would be welcome.

The present paper summarising project’s findings does not fully illustrate what has been achieved. To improve it, I would suggest returning to and exploring the results of anova analysis, and particularly of the Tukey test. Results of the latter are nowhere to be found, and in my opinion, Figure 2 (which should be re-worked anyway) would be a good place to show them. Although the figure in question is not overly precise, it indicates some differences between years, like a drop in salinity in summer 2021, to name one.

1. There are also some technical remarks needing Author’s attention:

2. l. 38: There are too few keywords; what about adding “Bay of Bengal”, for example?

3. l. 262ff. Perhaps opening paragraph of Discussion could be turned into a table.

4. Figure 1a is in need of improvement:

   1. The administrative division of Bangladesh is of no relevance to the paper,

   2. The map suggests that India and Myanmar had been inundated by the sea, and Bangladesh has remained as a lonely island.

   3. The points marking the sampling sites are too small, and their colours quite similar. The Authors should use different not only colours, but also shapes.

5. Figure 2 needs thorough re-working:

   1. Font throughout the figure needs enlarging.

   2. The ordinate axes in the graphs are too short, making any differences look inconspicuous.

   3. Colours of data points marks are too similar to one another. Use more contrasting colours and different shapes.

   4. Grey background should be removed.

6. Figure 4 is also in need of changes:

   1. Too small font throughout,

   2. Longer ordinate axes would make graphs more legible,

   3. Contrary to expectations grey background does not make graphs more legible.

   4. Colours in bar graphs are not contrasting enough.

7. Figures 5 and 6 should follow the abovementioned remarks.

8. Footnote of the Table 1. should be moved to the table heading.

9. Footnote of the Table 2. should be moved to the table heading.

10. l. 159ff.: In chapter 2.7 the statistical software is improperly cited. What is more, citations of the software should also appear in the references section, but the Authors neglected this.

11. l. 137: wrong formula for the H’ index. What does the part in square brackets mean?

12. ll. 141&144: What does the right square bracket mean in formulae?

13. ll. 197/198: What does “August 2, 2020” mean in the figure caption.

14. English is in need of substantial overhaul. Some examples justyfying such recommendation:

    1. l. 77ff.: in a phrase like: “ecology of the larval fisheries” the word “fisheries” is misused. “Ecology of fish larvae” is a safer alternative.

    2. l. 26: not: “four Estuary”, but “four estuaries”.

    3. ll. 45/46: the sentence: “Larval fishes show unique behaviours and other anatomical characteristics from adulthood” is unclear and needs re-working:

       • The words “and other” suggest that behaviours are anatomical characteristics.

       • Larvae are fish which have not reached adulthood yet. How then can they show behaviours […] from adulthood?

    4. l. 42: the phrase: “all of which are enhanced with nutrients” is unclear. Please rephrase.

As pointed out in the review, English requires thorough revision, preferably by a native speaker.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

Dear Editor and authors,

I have reviewed the manuscript entitled "Larval fish assemblages in coastal waters of Bangladesh". This is an interesting and relevant content for fish conservation and management and deserves to be published. However, I highlighted some points before to be accepted for publication. My concerns are related to the lack of a clear hypothesis and some unclearity in statistical analysis, especially RDA, which put in doubt some results. In addition, in the Discussion section, the authors just discuss spatial variation on fish larvae distribution and diversity like if there were significant differences among sites even if they didn't find any. Also, the authors didn't discuss anything about the significant seasonal variation observed. Please, find attached my minor comments that I hope to help the authors.

Comments for author File: Comments.pdf

See my comments on the PDF attached.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Please attend to the questions & points made in an attached file

Comments for author File: Comments.pdf

Vast improvement. Minor issues still present.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The Authors did improve the manuscript, yet they should be given more time to fine-tune it. I would like to draw their attention to the following points:

1. ll.63-72: Is this lengthy piece about fish species identification really necessary in this paper?

2. It would suffice to state once that in this study no accidental families were encountered. There is no need to repeat this several times throughout the manuscript. The paragraph in lines 146-148 should be rewritten accordingly.

3. Tables:

   1. Table 1:

      • Change scientific notation into “<0.001”

      • Is “1.34e-15” really bigger than 0.001?

   2. Table 3: There is no need for the last column. Stating in the text that there were no accidental species suffices (see 2. above).

   3. Table 4: The title is misleading. The table does not compare fish families, it compares results of different studies in regard to the number of recorded fish families. The sentence in line 284 should be changed accordingly.

4. The graphs in the Figure 2 are too dense to be legible. At least they should be arranged in one column, as in the Figure 5, with x-axes twice as long as at present. Colours should be contrasting (yellow for sure is not!). I would also suggest enlarging the symbols and the thickness of lines.

5. Do not allow page breaks split tables or figure captions.

6. Entire text is still in need of thorough language review! Just few examples of related issues:

   1. l. 26: “at four sites”, NOT: “in four sites”.

   2. l. 28: “representing”, rather than “consisting of”.

   3. l. 88: data “serve”, not “serves”.

   4. l. 141: “in [29]”, not “as [29]”.

   5. l. 155: remove “where”.

   6. l. 236: Figure 4 presents.

   7. Spelling of the Rezukhal site (Rezu Khal? — Fig. 2)

   8. The “3” in cubic metres should be printed as a superscript.

None apart from what I wrote in my review.

Author Response

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Author Response File: Author Response.pdf