Coastal Ecological Connectivity between Seagrass Bed and Marine Ranching 30 km Apart: A Case STUDY of Apostichopus japonicus Feeding on Seagrass Debris in the Bohai Sea, China

Round 1

Reviewer 1 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

The introduction section has too many paragraphs. I suggest condensing it into three sections: one for introducing the background and significance, another for explaining the purpose of the article. Overall, the findings of the article seem quite localized. Drawing the conclusions the author describes from such limited results is challenging.

Details:

Figure 3, I am not able to effectively obtain the standard deviation you described in the results, only the mean.

Please use the full name the first time an abbreviation appears. e.g. SCUBA

Try to use simple sentences in the article and avoid complex ones. e.g. Within this system lies China's largest seagrass bed—the eelgrass bed—spanning 3,217.32 hectares and exhibiting a perennial life cycle.

Revise the citation section to include opinions along with references. e.g. Xu, et al. [62] confirmed the presence of floating seagrass northeast of the bed, further affirming the transport of seagrass towards the marine ranching area. Verified presence of floating seagrass northeast of the bed strongly supports the idea that seagrass is being transported towards the marine ranching area (Xu et al., xxxx).

Comments on the Quality of English Language

The language still needs careful polishing and refinement

Author Response

The introduction section has too many paragraphs. I suggest condensing it into three sections: one for introducing the background and significance, another for explaining the purpose of the article.

Response:

We thank the reviewer’s positive and constructive comments, which are very helpful to improve the quality of our manuscript. According to reviewer’s suggestions, we have made extensive editing of English language. We use more recent references (complement or replace) in introduction and discussion. Detailed responses to the mentioned comments and suggestions are listed point by point.

According to reviewer’s suggestions, we have revised the Introduction, and we have mergeg 9 paragraphs into 5 paragraphs.

 

Details:

Figure 3, I am not able to effectively obtain the standard deviation you described in the results, only the mean.

Response:

According to reviewer’s suggestions, we have added the standard deviation in Figure 3.

 

Please use the full name the first time an abbreviation appears. e.g. SCUBA

Response:

According to reviewer’s suggestions, we have added the full name of SCUBA (Self-Contained Underwater Breathing Apparatus).

 

Try to use simple sentences in the article and avoid complex ones. e.g. Within this system lies China's largest seagrass bed—the eelgrass bed—spanning 3,217.32 hectares and exhibiting a perennial life cycle.

Response:

According to reviewer’s suggestions, we have revised the sentence.

“Within this system lies China's largest eelgrass bed. The seagrass bed covers 3,217.32 ha, and the foundation species Z. marina exhibits a perennial life cycle”

 

Revise the citation section to include opinions along with references. e.g. Xu, et al. [62] confirmed the presence of floating seagrass northeast of the bed, further affirming the transport of seagrass towards the marine ranching area. Verified presence of floating seagrass northeast of the bed strongly supports the idea that seagrass is being transported towards the marine ranching area (Xu et al., xxxx).

Response:

According to reviewer’s suggestions, we have revised the sentence.

Author Response File: Author Response.docx

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

Dear authors:

Your manuscript is not original, but it is good (consistent and easy for understand), I suggest these minor (obligatory changes):

1- In tittle, you must include what is "Apostichopus japonicus" (Echinodermata?).

2- In introduction, the first time that you cite "Apostichopus japonicus", you must mention the author of year of first description in according to taxonomical rules.

2- Use more recent references (complement or replace) in introduction and discussion.

3- In material and methods (data analysis), it is easy for understand, but I have a question:
       - Did you use R software? (R Development Core Team), if you used it, you must cite it.

       - Did you use R libraries ?

Thank you for your consideration, with my best wishes and blessings

Author Response

Dear authors:

Your manuscript is not original, but it is good (consistent and easy for understand), I suggest these minor (obligatory changes):

Response:

We thank the reviewer’s positive and constructive comments, which are very helpful to improve the quality of our manuscript. Detailed responses to the mentioned comments and suggestions are listed point by point.

 

1- In tittle, you must include what is "Apostichopus japonicus" (Echinodermata?).

Response:

According to reviewer’s suggestions, we have revised the title.

“Coastal ecological connectivity between seagrass bed and ma-rine ranching 30 km apart: A case study of the sea cucumber Apostichopus japonicus (Echinodermata: Holothuroidea) feed-ing on seagrass debris in the Bohai Sea, China”

 

2- In introduction, the first time that you cite "Apostichopus japonicus", you must mention the author of year of first description in according to taxonomical rules.

Response:

According to reviewer’s suggestions, we have added the author of year of first description in according to taxonomical rules.

“the sea cucumber Apostichopus japonicus (Selenka 1867)”

 

2- Use more recent references (complement or replace) in introduction and discussion.

Response:

According to reviewer’s suggestions, we have updated more recent references (complement or replace) in introduction and discussion.

 

3- In material and methods (data analysis), it is easy for understand, but I have a question:
- Did you use R software? (R Development Core Team), if you used it, you must cite it.

Response:

We used R software, and according to reviewer’s suggestions, we cited it now.

 

- Did you use R libraries ?

Response:

We used the R package MixSIAR, and we have cited this package.

Author Response File: Author Response.docx

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

Overall an very well-written and engaging manuscript. That said, I am not really sure or any real scholarship or advancement of science attendant to the paper. Here are a few  minor issues:

Lines 43-44: Seems that fish as a major user of seagrass beds should be mentioned here

Line 100: I have no idea what (Short) refers to.

Lines 261-289: Why the blue shading?

Lines 311-315: Again, why the blue shading?

 

Author Response

Overall an very well-written and engaging manuscript. That said, I am not really sure or any real scholarship or advancement of science attendant to the paper. Here are a few  minor issues:

Response:

We thank the reviewer’s positive and constructive comments, which are very helpful to improve the quality of our manuscript. Detailed responses to the mentioned comments and suggestions are listed point by point.

 

Lines 43-44: Seems that fish as a major user of seagrass beds should be mentioned here

Response:

According to reviewer’s suggestions, we have added fish in this sentence.

 

Line 100: I have no idea what (Short) refers to.

Response:

It should be (Green and Short, 2003), and we have revised it.

 

Lines 261-289: Why the blue shading?

Response:

The blue shading is the part we modified based on the reviewers' comments last time. Sorry for the confusion caused to you, and we have canceled the blue shading.

 

Lines 311-315: Again, why the blue shading?

Response:

The blue shading is the part we modified based on the reviewers' comments last time. Sorry for the confusion caused to you, and we have canceled the blue shading.

 

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

Comments and Suggestions for Authors

Review of Xu et al.

The paper presents an isotope-connectivity study to relate one mariculture resource (A. japonicus) with its food sources, with a focus on a distant seagrass beds that the same authors have heavily studied in the past based on the references published in international journals. It is an interesting study.

I am not sure if it is suitable for Sustainability as it is an ecological study without much of a management or human component at this stage (although I am sure there is potential).

I have to say that I am not competent specifically for the MixSIAR bayesian analysis, hence I will trust the authors. Assuming this part is correct, the other aspects requires minor modifications and modifications to enhance the manuscript.

English : the English is generally more than correct, but I have flagged some sentences to check. See at the end of the review.

Methods:

The location map needs to include a regional map to present where are the Bohai and Yellow Seas, and all the cites sites.

Sampling strategy: eventually it is not clear how many samples are processed for each sampling period. This need to be stated clearly. For example it is said that A. japonicus are sampled at each period, and that each sample is made of the tissue from 3 individuals, and that the standards is measured every 10 samples… but eventually how many specimens were collected to make how many samples. Pease add this information in table 1;

Results

In itself the results are not impressive, as seagrass only contribute to a narrow margin of the A. japonicus diet. Yet it is interesting to have demonstrated this link, 30 km apart.

Fig 2 should show the standard deviation shown in Table 2, not just the average.

Discussion:

Line <286- to 304 are not suitable here. They belong to the Introduction, but need to be shortened if added in the Introduction as a general information for seagrass as a food source.

The discussion should include at the end some thoughts beyond the study site. What other mariculture activities worldwide could benefit from similar isotopic/connectivity studies? Considering seagrasses but also other coastal systems (mangroves, estuaries, cities, etc.).

 

Minor comments:

References 3 and 64 are the same. Double check the reference list.

I would add in the title the distance (30km) between seagrass and ranching areas, hence… ‘between seagrass bed and marine ranching 30 km apart: A case …’.

Keywords could include mariculture

Line 42: remove ‘could

L65: ‘at’, not as

L91-99 should be better after Line 85. Better flow.

L115: ‘way means’ ?? rewrite

L133: remove ‘one of the form…connectivity’

L160-162 are off topic as we don’t really care here what was the impact of arificail oyster reefs. I would remove these lines

L207-208: check sentences

L231-232 I assume this list is sorted by feeding role importance.; so add ‘…in the region include, by order of decreasing importance:’ ; otherwise remove.

END OF REVIEW.

Comments on the Quality of English Language

see general comments.

Author Response

We are grateful to the reviewers' positive comments and constructive suggestions, which are very helpful to improve the quality of our manuscript. We have modified the manuscript accordingly. According to the reviewers’ suggestions, we found some interesting points in the discussion section. 

we have uploaded all reviewers in a file.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

General

It is an interesting study with relevant results about the connectivity between two ecosystems; the natural one and the artificial algae-shellfish reef ecosystem. However, although the isotopes methodology is suitable to accomplish the main objective, and the results can be useful for decision makers, the lack of a control sampling site makes difficult to establish the robustness of the results. Additionally, the discussion section appears to be more like a summary of information related to the topic than a formal discussion. It is necessary to work on this section thoroughly.

It would be convenient to include ocean circulation dynamics in figure 1 to better understand how material from the sea grass bed is transported to the artificial algae-shellfish reef area.

It is necessary to check spelling and grammar throughout the document and a thorough review by a native english speaker is advisable.

Particulars

Lines 32-35. The writing is confusing, so the idea you want to point out can not be understood.

Lines 55-58. It seems that the sentence is missing words, making the idea unclear.

Lines 106-108. Its necessary to improve writing.

Lines 108-114. Its necessary to improve writing.

Lines 212-214. It is unnecessary to describe what the results tables are; instead describe in the text the results you want to highlight and refer to the tables.

Lines 230-232. Maybe the authors wanted to say primary consumers. Please review.

Lines 248-250. This general information on the use of carbon and nitrogen isotopes is out of place in the discussion.

Lines 257-277. All this information seems more like a statement of the problem than a discussion. The authors should focus on the discussion of their results in this section.

Lines 278-280. This is the second time that the objective of the study is stated in this section of the document, which is excessive.

Figure 4. It is advisable to include in figure 1 the information contained in this scheme.

Lines 286-306. The authors made an extensive summary of the different organisms and mechanisms involved in the transfer of food energy on sea grasses in order to support their hypothesis, but a formal discussion is still needed.

Lines 307-311. Instead of well structured examination of the data, the authors present a mix of results with a bit of general information.

Lines 244-347. This information is the exactly same as that of lines 337-339.

Comments on the Quality of English Language

An extensive editing of English language is required

Author Response

We are grateful to the reviewers' positive comments and constructive suggestions, which are very helpful to improve the quality of our manuscript. We have modified the manuscript accordingly. According to the reviewers’ suggestions, we found some interesting points in the discussion section. 

we have uploaded all reviewers in a file.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript titled "Coastal ecological connectivity between seagrass bed and marine ranching: A case study of Apostichopus japonicus feeding on seagrass debris in the Bohai Sea, China" by  Xu et al., focuses on the ecological connectivity between seagrass beds and marine ranching. The study provides evidence of coastal ecological connectivity between seagrass beds and marine ranching. This is shown through the diet of Apostichopus japonicus, which includes seagrass, even though the marine ranching area is far from the seagrass bed. This is the only one key point for this study. The research methodology in this article primarily involves the collection of floating seagrass leaves and other biological samples (such as Japanese sea cucumbers and primary producers) for stable isotope analysis to determine the dietary sources of consumers. However, the authors do not provide a clear description of the sample collection and quantities, and I am uncertain that the conclusions described in the article can be drawn from such limited samples. Additionally, the highly regional nature of this study may not yield universally applicable conclusions. Therefore, I would not recommend the publication of this article.

Comments on the Quality of English Language

The manuscript titled "Coastal ecological connectivity between seagrass bed and marine ranching: A case study of Apostichopus japonicus feeding on seagrass debris in the Bohai Sea, China" by  Xu et al., focuses on the ecological connectivity between seagrass beds and marine ranching. The study provides evidence of coastal ecological connectivity between seagrass beds and marine ranching. This is shown through the diet of Apostichopus japonicus, which includes seagrass, even though the marine ranching area is far from the seagrass bed. This is the only one key point for this study. The research methodology in this article primarily involves the collection of floating seagrass leaves and other biological samples (such as Japanese sea cucumbers and primary producers) for stable isotope analysis to determine the dietary sources of consumers. However, the authors do not provide a clear description of the sample collection and quantities, and I am uncertain that the conclusions described in the article can be drawn from such limited samples. Additionally, the highly regional nature of this study may not yield universally applicable conclusions. Therefore, I would not recommend the publication of this article.

Author Response

We are grateful to the reviewers' positive comments and constructive suggestions, which are very helpful to improve the quality of our manuscript. We have modified the manuscript accordingly. According to the reviewers’ suggestions, we found some interesting points in the discussion section. 

we have uploaded all reviewers in a file.

Author Response File: Author Response.docx

Reviewer 4 Report

Comments and Suggestions for Authors

The study is important and may have relevance for future work on ecological connectivity in ecosystems, however, the discussion is very descriptive about processes and relationships that have already been described and focuses little on explaining more broadly the causes that originate the results obtained. The representativeness of seagrass in the sea cucumber diet is low and need of more solid arguments to explain and convince why this should be considered very important.

Author Response

We are grateful to the reviewers' positive comments and constructive suggestions, which are very helpful to improve the quality of our manuscript. We have modified the manuscript accordingly. According to the reviewers’ suggestions, we found some interesting points in the discussion section. 

we have uploaded all reviewers in a file.

Author Response File: Author Response.docx

Round 2

Reviewer 4 Report

Comments and Suggestions for Authors

The document has been  improved, however, the weakest section of the paper continues to be the discussion, since despite the fact that information was added, the importance of seagrass beds in marine ranching is still not clearly explained or highlighted. There are mentions about connectivity and in fact, the title of the paper refers to connectivity, however, it is not extensively addressed, nor is it explained why, despite the fact that grasses constitute a low proportion of the sea cucumber diet, should be important for oyster farming. I consider that this is the main weakness of the paper, the results do not provide enough elements to highlight that seagrass beds are essential for marine ranching, at least in this particular case.