PONE-D-23-00568Morphometric responses of two zooxanthellate octocorals along a water quality gradient in the Cuban northwestern coastPLOS ONE

Dear Dr. Rey Villiers,

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.

==============================

The reviewers agree that this is worthy of publication, but that there are some areas that need to be addressed before this can be accepted. Please see the reviewers comments below. Thank you!

==============================

Please submit your revised manuscript by Jul 08 2023 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 rebuttal 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,

Nikki Traylor-Knowles, Ph.D.

Academic Editor

PLOS ONE

Journal requirements:

When submitting your revision, we need you to address these additional requirements.

1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at

https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and

https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf.

2. In your Methods section, please provide additional information regarding the permits you obtained for the work. Please ensure you have included the full name of the authority that approved the field site access and, if no permits were required, a brief statement explaining why.

3. We note that [Figure 1] in your submission contain [map/satellite] images which may be copyrighted. All PLOS content is published under the Creative Commons Attribution License (CC BY 4.0), which means that the manuscript, images, and Supporting Information files will be freely available online, and any third party is permitted to access, download, copy, distribute, and use these materials in any way, even commercially, with proper attribution. For these reasons, we cannot publish previously copyrighted maps or satellite images created using proprietary data, such as Google software (Google Maps, Street View, and Earth). For more information, see our copyright guidelines: http://journals.plos.org/plosone/s/licenses-and-copyright.

We require you to either (1) present written permission from the copyright holder to publish these figures specifically under the CC BY 4.0 license, or (2) remove the figures from your submission:

a. You may seek permission from the original copyright holder of Figure 1 to publish the content specifically under the CC BY 4.0 license. 

We recommend that you contact the original copyright holder with the Content Permission Form (http://journals.plos.org/plosone/s/file?id=7c09/content-permission-form.pdf) and the following text:

“I request permission for the open-access journal PLOS ONE to publish XXX under the Creative Commons Attribution License (CCAL) CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). Please be aware that this license allows unrestricted use and distribution, even commercially, by third parties. Please reply and provide explicit written permission to publish XXX under a CC BY license and complete the attached form.”

Please upload the completed Content Permission Form or other proof of granted permissions as an ""Other"" file with your submission.

In the figure caption of the copyrighted figure, please include the following text: “Reprinted from [ref] under a CC BY license, with permission from [name of publisher], original copyright [original copyright year].”

b. If you are unable to obtain permission from the original copyright holder to publish these figures under the CC BY 4.0 license or if the copyright holder’s requirements are incompatible with the CC BY 4.0 license, please either i) remove the figure or ii) supply a replacement figure that complies with the CC BY 4.0 license. Please check copyright information on all replacement figures and update the figure caption with source information. If applicable, please specify in the figure caption text when a figure is similar but not identical to the original image and is therefore for illustrative purposes only.

The following resources for replacing copyrighted map figures may be helpful:

USGS National Map Viewer (public domain): http://viewer.nationalmap.gov/viewer/

The Gateway to Astronaut Photography of Earth (public domain): http://eol.jsc.nasa.gov/sseop/clickmap/

Maps at the CIA (public domain): https://www.cia.gov/library/publications/the-world-factbook/index.html and https://www.cia.gov/library/publications/cia-maps-publications/index.html

NASA Earth Observatory (public domain): http://earthobservatory.nasa.gov/

Landsat: http://landsat.visibleearth.nasa.gov/

USGS EROS (Earth Resources Observatory and Science (EROS) Center) (public domain): http://eros.usgs.gov/#

Natural Earth (public domain): http://www.naturalearthdata.com/.

Additional Editor Comments:

Dear Dr. Nèstor Rey Villiers,

I want to apologize for the length of time that it took for these reviews to come back to you. It has been challenging to find reviewers. Thank you for your patience.

Sincerely,

Nikki Traylor-Knowles

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

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: Yes

Reviewer #2: Partly

**********

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

Reviewer #1: Yes

Reviewer #2: I Don't Know

**********

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: Yes

Reviewer #2: No

**********

4. 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

**********

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: This is a novel manuscript that examines the morphology of two octocoral species in the north of Cuba. The corals occur across a gradient of anthropogenic influence, and the study shows interesting and convincing evidence of site/water quality related influences on the growth of the corals. I found the study design and analysis to be sound and the results interesting and insightful in terms of the influence of water quality.

The study builds off of a previous investigation of the study sites, including water quality work, which builds off of the previous Rey-Veilliers work (citations 12, 25). In the introduction, it would be helpful to set the stage of the previous work and then mention how this new work builds upon and extends that work. Since some of the data seem to be used in multiple publications (or else are related), it would be helpful to better explain these connections. For example, in lines 126-151 of the materials and methods, the authors present the overarching results of the water quality analysis, which is usually material that is presented in the Results. I understand that the authors are not actually showing that data here, but rather related data. Thus, the authors just need to make these differences clearer to the reader.

The manuscript was overall very well written and I appreciate the time that the non-native English speakers took to make the work presentable. I found a few sentences that were oddly worded, and offer suggestions below.

Line 37: Change to ‘Octocoral abundance is increasing on Caribbean reefs’

Line 40: change to ‘The aim of this study was to determine….’

Line 42: change to ‘on eight forereefs of northwest Cuba’

Line 43: change to ‘within a belt transect’

Lines 47/48: change to ‘hydrodynamic stress was the factor most negatively affecting P. kukenthali morphophometry’

Line 48: define hydrodynamic stress

Lines 48/49: The chronic effect of poor water quality over time resulted in more small sized colonies at the polluted site’

Line 53/54: change ‘water quality degradation’ to ‘poor water quality’

Lines 53-56: change to ‘This study suggests that poor water quality decreases the size and thus availability of octocoral habitat (e.g., E. flexuosa) while other tolerant species (e.g., P. kukenthali) are more tolerant of pollution.

Lines 116-117: change to ‘does the chronic effect of decreased water quality impact the height of both species over 9 years?’

Lines 118-120: Here it indicates that you will be describing the water quality measurements that you took for this study – this is part of the reason it is confusing as to what data was presented previously compared to what data is novel or set within a new context in this manuscript.

Reviewer #2: Review comments for “Morphometric responses of two zooxanthellate octocorals along a water quality gradient in the Cuban northwestern coast”

COMMENTS TO AUTHORS

Summary

This manuscript review examines the morphometric response of two octocoral species, Eunicea flexuosa and Plexaura kükenthali, in a water quality gradient within Caribbean reefs. The authors investigate the potential causes behind the increasing abundance of octocorals in this region, focusing on the species' vertical morphological plasticity and their ability to adapt to environmental gradients. The study was conducted between 2008 and 2016, encompassing eight fore reefs in the Cuban northwestern area. Various morphometric indicators were measured in colonies of both species along belt transects at each site. The findings reveal that E. flexuosa exhibited lower morphometric values (height, diameter, number of terminal branches/colony, cover index, and arborescent colonies) in areas with higher anthropogenic pollution. In contrast, the morphometry of P. kükenthali was primarily affected by hydrodynamic stress rather than water quality, although the authors’ methods for determination of hydrodynamic stress are unclear. Over the study period, water quality degradation led to a higher percentage of smaller-sized colonies of E. flexuosa, likely due to increased mortality. Similarly, the size distribution of P. kükenthali exhibited a similar trend but correlated with sites experiencing greater hydrodynamic stress. Overall, the study sheds light on the complex relationships between water quality, morphometric characteristics, and octocoral species dynamics in Caribbean reefs, and represents a valuable contribution that should be accepted following major revisions to provide context and clarity.

Major comments

1. Please expand the introduction and discussion to highlight the systematic relationship between the octocoral species studied here – how might these results extrapolate to other octocoral species or genera with comparable life histories and morphological traits? Other genera and their tolerances to various stressors are casually mentioned throughout the manuscript, but it is difficult for the reader to understand how these octocorals are related to one another and how different responses to water quality can impact their ecological success.

2. I would encourage the authors to include photographs of their study species, and a depiction of the morphometric characters that are being measured in the current study. This will help readers understand the differences in morphology that exist between the species. Representative photos showing the differences in morphology between E. flexuosa along the water gradient would also help illustrate the morphometric changes discussed in the manuscript.

3. Lastly, I politely recommend that the authors revise sentences for proper English grammar and improve phrasing for clarity and conciseness throughout the manuscript. There are many cases of extraneous prepositional phrases and inverted sentence structure that make it difficult to understand the main points of a paragraph. Also, the repetition of paragraph structure for results presented for E. flexuosa and P. kükenthali makes it hard to determine which species is the focus.

Minor comments

Abstract

Line 37: a grammatical correction is needed here: “The abundance of octocorals is increasing on Caribbean reefs...”

Line 40: correct to “The aim of this study was to determine...”

Line 47 – 48: consistent use of the correct tense is needed here: “..., however hydrodynamic stress was the factor that most negatively affected the morphometry of P. kükenthali.”

Introduction

Lines 60 – 61: The first sentence has awkward phrasing, please consider revising, for example, “Coral reef ecosystems are biodiversity hotspots that support high biological productivity and provide goods and services to society.”

Lines 61 – 63: Consider rephrasing to “Octocorals contribute substantially to supporting coral reef biodiversity and are the second most common group of sessile organisms on the reefs of the Caribbean and Indo-Pacific.”

Line 65: give the definition of “hermatypic” (reef-building) here in parentheses for unfamiliar readers, or use “scleractinian corals” for taxonomic clarity throughout the manuscript.

Lines 78 – 80: The evidence that shows certain octocorals’ morphologies are differentially susceptible to water quality should be discussed in more detail – which species/taxa exhibit these responses, and to which specific water quality parameters?

Line 95: What is the systematic relationship between P. kükenthali and E. flexuosa? Understanding the evolutionary relatedness of the study species will help the readers contextualize the results. Do these species have other differences in life history strategies?

Lines 108 – 110: Consider rephrasing to “Therefore, other morphometric indicators including the total length of the branches, height, diameter, height/diameter ratio, cover index and surface area are measured to determine octocoral size.” Also, two sentences starting with “Therefore” in a row is awkward and not appropriate.

Lines 116 – 117: rephrase poor wording, consider “Does the chronic effect of water quality degradation result in a decrease in height of both species over a 9 year (2008-2016 period)?”

Methods

Lines 131 – 132: rephrase for clarity, consider “The sampling sites were located on fore reefs approximately 120 to 700 m from the coast, at a depth of 10 m (Fig 1).”

Lines 171 – 174: Can you provide more information on how the HSI was determined? Which 11 octocoral species are used? If the HSI is not independent of P. kükenthali relative abundances, how can the morphometric response of P. kükenthali be driven by the hydrodynamic stress? This methodological approach and the consequences for the manuscript’s conclusions must be made clearer.

Lines 195 – 196: Please also report the mean and standard deviation of numbers of colonies per site.

Lines 219 – 221: Move the sentence on testing for normality earlier in the paragraph, it reads as an afterthought here.

Results

Lines 252 – 253: unclear, change to “similar variation as the colony diameter”, also was this lack of difference in variation confirmed with a statistical test?

Lines 295 – 297: Report which test was used to determine the percent variation in morphometric indicators explained by the water quality gradient, and clarify phrasing with the next sentence, consider “... E. flexuosa, indicating that water quality...”

Line 305: correct to “significant negative correlation” and cite a figure or table that contains these results.

Line 307: correct to “significant positive correlation” here and wherever this occurs (Lines 309, 310, 312, etc.)

Discussion

Lines 390 – 393: This sentence is too long and confusing, please separate the two discussion points or rephrase to state the conclusion first, followed by the lines of supporting evidence.

Lines 400 – 404: Also unclear, please correct for clarity and conciseness – what does “latter” refer to? Consider replacing use of “coincide” with a different phrase, for example “is similar to”.

Lines 412 – 418: Provide more specific evidence that suggests there are differences in tolerance of organic pollution between species. The linkages between the data, results, and conclusions here are tenuous and require more explanation.

Lines 422 – 426: These sentences are unclear, but it seems obvious that decreases in abundance would also result in smaller sizes of remaining colonies. Rephrase and clarify.

Lines 438 – 440: This sentence is not concise and needs to be edited to remove unnecessary prepositional phrases (“in the abundance”, “of the group”, etc.).

Lines 441 – 443: This sentence hangs on to the end of the paragraph and needs to be given more context or be removed – the genera Eunicea and Pseudoplexaura are not the focus of this study, and so the fact that these octocorals have developed tolerance mechanisms to heavy metals in the Red Sea must be put in context with the impacts of the water quality gradient in Cuba.

Lines 541 – 542 & Lines 548 – 549: Please explain the apparent contradiction in conclusions and clarify these sentences.

**********

6. 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.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

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

**********

[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.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Morphometric responses of two zooxanthellate octocorals along a water quality gradient in the Cuban northwestern coast

PONE-D-23-00568R1

Dear Dr. Rey Villiers,

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.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

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,

Nikki Traylor-Knowles, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

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 #2: All comments have been addressed

**********

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 #2: Yes

**********

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

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 #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 #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 #2: I am impressed with the thorough response to the previous comments, and recommend the manuscript for publication.

The introduction, methods, results and discussion sections are much improved, and benefit from a clearer contextualization of this work in relation to previous studies. I have also noted that you addressed some minor language and grammatical issues, which have improved the overall readability of the manuscript. Thank you for your diligence in improving the phrasing and logical flow of the manuscript's paragraphs.

The included images of the study species in the supplemental figure 1 are much appreciated, and help connect the reader to the differing geometry of the species under investigation. In addition, thank you for providing additional information about the different life history strategies of these species, and how within-genera evolutionary relationships may not offer clear explanations for octocorals' ecological niches, but rather specific life history strategies (such as height, morphology) are more important.

Considering the quality of your work and the efforts you have put into addressing the reviewers' feedback, I am pleased to accept your manuscript for publication.

**********

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.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

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 #2: No

**********