-->PONE-D-25-29750-->-->Valuing conservation and natural wealth: The blue economy of manta ray watching in the Maldives-->-->PLOS One

Dear Dr. Moloney,

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Additional Editor Comments:

You will see that both reviewers generally have a favourable view of the manuscript, but that some changes are required. Please take care to address all of the points raised by the reviewers when making your revision.;

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-->Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. -->

Reviewer #1: No

Reviewer #2: Yes

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-->2. Has the statistical analysis been performed appropriately and rigorously? -->

Reviewer #1: No

Reviewer #2: Yes

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-->3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.-->

Reviewer #1: No

Reviewer #2: Yes

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-->4. Is the manuscript presented in an intelligible fashion and written in standard English?

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Reviewer #1: Yes

Reviewer #2: Yes

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-->5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)-->

Reviewer #1: Review of PONE-D-25-29750

This article is an important contribution to the literature on the economic value of nature-based tourism. It serves as an important piece of information to highlight often hidden benefits of biodiversity conservation for local economies. There are significant shortcomings related to the methods used that need to be addressed before considering publication.

1. Is the manuscript technically sound, and do the data support the conclusions?

Due to methodological issues, the manuscript is not technically sound and does not support the conclusion in its current state. The manuscript requires major revisions in the methods to be considered for publication.

2. Has the statistical analysis been performed rigorously and appropriately?

• The term “total economic value” or total economic benefit” is not appropriate. Check Randall 1987. You are only looking at direct use of the use value category.

• Operator surveys: some questions are worded as if the questions were targeting the visitors, not the operators. “What was the cost per guest dive …?” is vague. Since it’s an operator survey, I assume you asked about operating costs, what the dives cost the operator, not cost the diver/customer. If so, why did you not specify subcategories to then more precisely model these expenditures in the wider economy? In any case, revenue = dives * price, not dives * cost.

• Given this issue, how sure are you that operators actually responded with their operating costs and not price charged, or vice versa? I think what you really were after was “price”, not “cost”, in order to calculate revenue. E.g. L239: In this sentence it looks like you used the term “cost” as meaning the price the operator charged for a package/experience/dive, etc.

• For non-respondents, how did you determine the number of dives these non-responding operators had in the study year? On their websites, did you look for their capacity, e.g. number of vessels or dive guides, etc. to give you a better sense than just taking the average of whatever grouping the operator fell into? How did you verify your assumptions?

• L272 – L277: What if the tour operator didn’t update the website to reflect current prices? How did you deal with outliers? Did you employ any statistical approach to identify them? Citation missing.

• With many experiences sold as packages, it’s unclear how you divided packages offered on websites into the categories you outlined in Equation 1.

• One major issue is double counting in Eq1. Tour operator revenue already includes taxes eventually paid to the government, thus you are counting them twice in Eq1, once as part of TOR and again as TX. Similar double counting occurs with guide license fees that are part of MPAR, occurring twice in Eq1, once in the TOR and again in the MPAR.

• TE is problematic with packages as opposed to paying for dives solely. Again, how did you divide up what visitors paid for packages into diving/viewing and accommodations, etc.

• Check all other equations for issues of double counting.

• Converting from Rufiya to US$ you used an exchange rate on a certain date instead of purchasing power parity that considers differences in the cost of living and is the economic approach necessary in this instance .

• Eq6 calculation of LV is not theoretically sound as it must consider the opportunity cost of natural capital, some sort of discount rate, or if omitted a discussion that justifies it.

3. Have the authors made all the data underlying the findings in their manuscript fully available?

Not yet. The authors should specify what data archive will host the data. Usually, it is better practice to publish the data in a data depository, providing the DOI to reviewers.

4. Is the manuscript presented in an intelligible fashion and written in standard English?

Well written manuscript. The following are minor suggestions to improve clarity and flow.

• Check spelling of the short title: economic or economy

• Abstract: second to last sentence, eliminate “were”. Language is a bit pretentious and inflated.

• Consider “charismatic” instead of “flagship species”. Animals are not manufactured assets, such as ships.

• Change “economic evaluation” to “economic valuation”. You are not comparing economic performance against some sort of evaluation metric or a standard but instead you quantify values, thus, use “economic valuation.” Evaluation is a different social science method.

• Many instances of the use of “this” without actually naming what this is, specifically this followed by an object. Search and replace any “this”, and either eliminate or name what “this” is. I can read that mostly you refer to the prior sentence, but your writing becomes so much more clear if you synthesize the prior sentence using a term. L 54 for example, instead of “Despite this” write: “Despite the public intent to conserve, policy makers … “

5. Additional comments:

Introduction

• Usually, intros are 2 double-spaced pages. Consider condensing significantly, perhaps to less than half the current length. Be concise on how your research fits into the broader literature. Perhaps, insert a subheading for manta ray ecology. Unless you compare the economic numbers from the literature to your results, there isn’t much need to present them all here.

• L163: unclear what negative pressure. From development or unenforced viewing regulations or some other factor.

Methods

• The first section belongs into the intro. This is background material, not methods. Instead, the methods section should start with your study design.

• What was your sample size and response rate for the pilot?

• L262, comparing response rates to other studies belongs into the discussion.

• L366: United States not “stated”

• L387-390: how did you estimate this?

• L399-404: how was this “text mining” done? A careful analysis of text is usually done following qualitative data analysis that includes determining coding categories before analyzing text. This approach can then be used to carefully assess motivations. Word clouds are problematic and should not be used in academic publications as there is no analysis, no rigor. They are good for presentations and data exploration.

Reviewer #2: This MS is well written, and the authors successfully highlight its value. First of all, as an updated study of the economic value of Maldives MRW after more than a decade is very important for future management. This study also highlights the discrepancy in staff salary revenue between Maldivian and expatriate staff, as well as the need for more stable funding that supports in-country conservation from tourism. Further, this study is also very important for backing arguments against unsustainable fishing practices (such as the recent plan to legalise shark fishing in the Maldives in 2024) and any future threats to biodiversity. Minor improvements are needed, including elaboration on fisheries and cultural significance.

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Reviewer #1: No

Reviewer #2: Yes: Muhammad Ichsan

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Attachments

Attachment

Submitted filename: Review MI.docx

-->PONE-D-25-29750R1-->-->Valuing conservation and natural wealth: The blue economy of manta ray watching in the Maldives-->-->PLOS One

Dear Dr. Moloney,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Apr 20 2026 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:-->

• A letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

-->If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Joel Harrison Gayford

Academic Editor

PLOS One

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If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise.;

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

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Reviewers' comments:

Reviewer's Responses to Questions

-->Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.-->

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

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-->2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. -->

Reviewer #1: Yes

Reviewer #2: Yes

**********

-->3. Has the statistical analysis been performed appropriately and rigorously? -->

Reviewer #1: Yes

Reviewer #2: Yes

**********

-->4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.-->

Reviewer #1: Yes

Reviewer #2: Yes

**********

-->5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.-->

Reviewer #1: Yes

Reviewer #2: Yes

**********

-->6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)-->

Reviewer #1: I thank the authors for their continued and quite extensive efforts to improve this manuscript. I can accept the revisions and the paper should be published after some additional minor modifications, that I may suggest as follows:

• Figures are all low dpi, increase dpi to at least 300dpi, Fig 3 fonts need to be legible, Fig. 4 has missing axis and missing labels … what are you showing?

• Lines 574-577. Explain the different methods used in the past and that you use and then give an honest assessment of your estimate describing factors contributing to over and underestimating the true value. It’s good that you cite numbers to validate growth but your estimate needs more discussion how it fits past estimates and how not. Also, check the statement in the quoted lines. To me it is a bit contradictory. Consider revising to eliminate the contradiction.

The discussion section could benefit from a few suggested points:

- Discrepancy between foreign and Maldivian staff salaries, despite the latter most likely having better local knowledge. You could specifically point out the distribution of benefits between local and foreign staff with policy implications. Why are foreign guides needed? Could the government levy a tax for foreign guides and use that income to bolster local guides’ workforce development, education, etc. Also, note that the involvement of locals in conservation-oriented tourism such as manta ray guiding and promoting local employment in this sector with rising wages could significantly play into competing successfully against opportunities locals have in the illegal harvesting sector of the manta ray economy. Harvesters may have traditional knowledge that they could immediately deploy in the tourism sector if wages are better there.

- Hanifaru seems to have much higher ray density. Why is that? Are protections working? If so, could those be applied to other areas to increase ray habitat and populations there and perhaps distribute visitor pressure across more viewing locations? Your numbers speak to implementing the same rules that Hanifaru has to other areas. Are any of the visitation rates limited by regulation, managing congestion and negative impact on ray health?

Reviewer #2: All my comments have been satisfactorily addressed by the authors.

Publications on manta ray tourism values in the Maldives are mostly non-species-specific, and some targeting manta rays are outdated, making this publication an original and updated source of information.

The authors acquired and stated the ethics permit and permit exemption required and ensured the anonymity of respondents in the MS.

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-->7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

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Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.-->

Reviewer #1: No

Reviewer #2: No

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[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

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NAAS will assess whether your figures meet our technical requirements by comparing each figure against our figure specifications.

-->

Valuing conservation and natural wealth: The blue economy of manta ray watching in the Maldives

PONE-D-25-29750R2

Dear Dr. Moloney,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Joel Harrison Gayford

Academic Editor

PLOS One

Additional Editor Comments (optional):

Reviewers' comments: