Review Reports - Community-Based Monitoring for Rapid Assessment of Nearshore Coral Reefs Amid Disturbances in Teahupo’o, Tahiti

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I think this is a strong and interesting paper. I especially appreciate the citizen science aspect and the targeted application of the case study to the upcoming Olympics construction.

My comments are listed below. Most are minor suggestions and/or typos. My main comment is that the authors need to more explicitly describe how they calculated the total impact area for the Tower Footing location and the dredge area, since the final dollar value estimate hinges on this area estimate. I also think it would be a good idea to add a map and paragraph to the Materials and Methods section that describes the study area.

Thank you for your research and advocacy! Best of luck.

Abstract:

Page 1, Line 1: This is more a matter of opinion, so please feel free to ignore, but the title is a bit of a mouthful. I understand that it contains a lot of good info, but would it be feasible to streamline it a little bit?

Page 1, Line 17: Please insert a comma after "Tahiti".

Introduction:

Page 1, Line 38: Please insert a comma after "ecosystem".

Page 1, Line 39: I think there might be a typo here. Should this phrase instead read "the species richness ranges" or "their species richnesses range"? As currently written, there is subject-verb disagreement between "species richness" (singular) and "range" (plural).

Page 3, Line 100: Please insert a comma after "Tahiti".

Materials and Methods:

Page 3, Line 125: I think it would be a good idea to add a map and brief paragraph at the beginning of the Materials and Methods section that shows/describes the study area's location within the broader context of Teahupo'o and Tahiti as a whole. How many people live in Teahupo'o? Where is it located on the island? Do other threats/challenges exist for coral reef conservation? Etc.

Page 4, Line 143: Please add some more specifics to the caption for Figure 1. What was the source(s) of the orthophotos showing the the overall study area? Are the images in the inset boxes photos collected by citizen scientists? If so, please indicate as such.

Page 4, Line 143: I think it would be a good idea in the figure legend to specify that this is the proposed dredge area, rather than just saying "dredge area". I know y'all specify in the text above and below, but I think it would be good to also say it here in the figure legend.

Results:

Page 5, Line 209-210: I think there is a H' value missing from this sentence. Only two H' values are listed in the sentence, but Figure 2a shows that each of the three locations had a different H' value.

Page 7, Line 250: How did you calculate the impact area for the Tower Footing location? Please describe how you made this calculation, either here and/or in the Materials and Methods section.

Discussion:

Page 8, Line 277: The authors note that the existing concrete pilings have likely stimulated the growth of a diverse coral community. Would the proposed new pilings have the same effect in the long run?

Page 10, Line 323: Please remove the comma after "coral diversity".

Author Response

Reviewer 1:

I think this is a strong and interesting paper. I especially appreciate the citizen science aspect and the targeted application of the case study to the upcoming Olympics construction.

Thank you for your research and advocacy! Best of luck.

Abstract:

Thank you for your suggestion and we have revised the title to be more streamlined.

Page 1, Line 17: Please insert a comma after "Tahiti".

This has been added.

Introduction:

Page 1, Line 38: Please insert a comma after "ecosystem".

This has been added.

This sentence has been revised to pluralize “range” to “ranges”.

Page 3, Line 100: Please insert a comma after "Tahiti".

This has been added.

Materials and Methods:

Thank you for your suggestion, we have added a paragraph about Teahupo'o that describes the location, environment, population, and recognition in the surfing world. [lines 138-148]

We have added more specifics to this caption based on your suggestion and indicated that the inset orthophotos were generated from the community-based surveys and the larger map/orthophoto was generated from a UAV survey.

We have made this change as well to clarify it is a proposed dredging area and removed the proposed 2,500m2 area based on suggestion by Reviewer 4.

Results:

Thank you for catching this and we have added the third H’ value.

Page 7, Line 250: How did you calculate the impact area for the Tower Footing location? Please describe how you made this calculation, either here and/or in the Materials and Methods section.

We determined the survey area by simply imaging the entire area of the existing 12 footings with a 2-m buffer around the border. This information has been added to the Methods section. [lines 239-244]

Discussion:

We wish not to speculate as the Olympic Committee has not released detailed plans on the size or material of the proposed footings. We also don’t know how coral recruitment and growth may be affected by the construction and dredging and thus prefer not to speculate on something for which we lack data to make a reasonable speculation.

Page 10, Line 323: Please remove the comma after "coral diversity".

This has been removed.

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors, I have read and reviewed with vivid interest your manuscript submitted to the "Remote Sensing" journal as "Communication". Besides, a few days before receiving the review request, I came across a story on social media about the Teahupo'o reef. I was impressed by the videos and the people who were fighting to save the reef environment from the construction of a new platform for the 2024 Olympic Surf Event. I think that the presented manuscript highlights the power of citizen science as an effective method to collect fast and reliable data that can be used to monitor the areas, assess the ecological structure of coral communities and estimate the potential impacts that could be derived from direct anthropogenic disturbances. The manuscript well explains how local communities can easily learn how to use underwater photogrammetry to obtain 2D and 3D models of coral reefs. These models can then be processed to obtain functional parameters, which can be used to assess the status of the reefs and estimate the monetary value of benthic environments.

The manuscript is suitable for the "Remote Sensing" journal, and I recommend publishing it after making a few minor revisions listed here below.

-Materials and Methods: It is not specified how deep the three surveyed sites are and what is needed (time x area) to complete the surveys. I suggest adding this information to the "three-dimensional photogrammetry surveys" paragraph.

-Results: LINE 198-200, please check the GSD values. I think there is something wrong with the scale.

I suggest separating the last part of the discussion (LINE320-333) and add to a "Conclusion" paragraph.

Best regards and good luck!

Author Response

Reviewer 2:

The manuscript is suitable for the "Remote Sensing" journal, and I recommend publishing it after making a few minor revisions listed here below.

This information (depth and time) has been added to the 3D photogrammetry survey paragraph in the methods section.

-Results: LINE 198-200, please check the GSD values. I think there is something wrong with the scale.

The GSD and RSME values have been checked and are correct. They are small values because the surveys are shallow and thus the camera was a short distance from the photographed subject (reef habitat).

I suggest separating the last part of the discussion (LINE320-333) and add to a "Conclusion" paragraph.

We appreciate this suggestion and have moved the last part of the discussion into a “Conclusion” paragraph.

Best regards and good luck!

Thanks!

Reviewer 3 Report

Comments and Suggestions for Authors

Assessment:

This manuscript was a short assessment of a dredging project on coastal reefs. It includes a lot of claims about community education and communication science that were never assessed “qualitatively and quantitatively”. These are science branches that have a lot of tools for assessing what the authors claimed in this manuscript. I would add one of these scientists as a reviewer to tell how these claims were thrown out in the text. I made some comments criticizing the title and also at the last lines of my review. Also, no assessment of remote sensing techniques was included. It was all about some biological data. No conclusion section is in this manuscript and all the sections have major problems. This manuscript I think needs to be rewritten and revised and is not good enough for publication in this journal.

Major Comments:

Title: The claim about the word “rapid” was never assessed in this manuscript and is just a claim. This needs to be removed from the title. The same is true about “community-based monitoring”. The other claim about “disturbance from coastal development” is not accurate, too. The only thing I saw was a dredging project and other aspects of “coastal development” were not discussed.

The introduction section needs a major revision because of three main reasons:

1- No information about modeling and the importance of monitoring critical use in modeling was discussed in the Introduction section.

2- Endangered coral in the Red Sea and other parts of the world due to desalination and climate change effects were not discussed in the introduction section.

3- The sudden start of talking about Teahupoʻo, Tahiti community at line 100 without any background about the location, characteristics, etc is very disappointing. This needs to be organized as a separate section under the introduction section so that we know where you start talking about and then move to the Olympic event.

The Methods section:

1- Again no information about the region, its characteristics, people, source of income, climate, etc. How should people from other parts of the world know about this location? This section can also be a subsection of Methods.

2- The community people are not fishermen?

3- No information about the sites. Why were they selected, their location in the study region, and their characteristics?

4- This section needs a flowchart showing the process described in the text.

Results:

1- What do you mean by “dredging through the lagoon and construction” in line 252? Please get into details of this. I did not see any assessment of potential climate and anthropogenic change effects in this manuscript. You need to dig into such situations.

2- I did not see any assessment of tools that were used, their accuracy, errors, etc. This is a Remote Sensing journal and not a biology journal. I would like to see some graphs related to techniques and assessment of different techniques and their effect on the quality of results.

Minor and Specific Comments:

Line 131: What do you mean by 3D photogrammetry techniques? Details and more examples are needed.

Line 138-139: No information up to now about these sites. Very vague.

Line 140: Why one representative?

Line 160: Citation for the software.

Line 180: Shannon diversity index needs citation.

Line 190: m2 area????

Figure 1: Where’s the location of this area in the country and province? This should be shown by a small map in the top right corner. This map needs lat-long. Also, 2500 m2??? Check all the superscripts that need to be corrected.

Line 194: covers is correct.

Line 194-195: The sentence has two verbs. Rewrite it, please.

Line 197: These what? Images?

Line 205: “A high value of species richness” is a too general sentence. Be specific.

Figure 2a and b: The worst choice for selecting color.

Line 320-322: This needs to be assessed by communication and community education scientists. You made a claim here but no data (qualitative and quantitative) were shown. This a science field and the claims need to be proved. How should I accept this without knowing the previous knowledge of the people selected, and without any data about the timing, etc…

Comments on the Quality of English Language

Some English problems that can be solved easily

Author Response

Reviewer 3:

Assessment:

Major Comments:

The title has been revised based on comments from reviewer 1. The surveys were completed in one day, and took no longer than 15-min. The time to complete the surveys was added to the materials and methods section and can certainly be classified as “rapid” due to the short time to complete this work. We also explain in the methods and discussion that the community members completed the surveys. The training details are provided in the methods. Considering that community members completed and organized the surveys it is reasonable to refer to this work as “community-based”. To be more specific, we removed “coastal development” and replaced it with “disturbances” in the title and “construction” in the abstract and introduction.

The introduction section needs a major revision because of three main reasons:

1- No information about modeling and the importance of monitoring critical use in modeling was discussed in the Introduction section.

This information is provided in the introduction. We are not referring to statistical modeling, but instead 3D modeling. This is covered in detail in lines 86-137 in two paragraphs. The paper is not about using any other form of modeling.

2- Endangered coral in the Red Sea and other parts of the world due to desalination and climate change effects were not discussed in the introduction section.

Since this is a communication article, we are keeping the information specific and relevant to reefs in Tahiti and the South Pacific region. The paper highlights how 3D tools can be used for ecological monitoring and rapid assessments, but the focus is not on global stressors such as climate change or local stressors such as desalination.

We have added another paragraph based on your suggestion and reviewer 1. This paragraph provides details on characteristics of Teahupoʻo such as location, environment, and demographics. [lines 138-148]

The Methods section:

As mentioned above, we added this information to the introduction section.

2- The community people are not fishermen?

We have added this category to the community description.

3- No information about the sites. Why were they selected, their location in the study region, and their characteristics?

Site information and selection is described in the introduction and methods section. It is stated that the sites were selected due to the proposed tower construction location and the dredging path in the lagoon. We added another statement as to why these sites were selected in the methods to clarify that they are in directly located where proposed activities will damage the reef substrate. [lines 206-212]

4- This section needs a flowchart showing the process described in the text.

The workflow for 3D photogrammetry has been well detailed in prior publications and since this is a “Communications” article we want to keep the content specific to the work conducted to assess potential damage to the reef. We cited the relevant literature that documents the workflow in detail.

Results:

As described in the manuscript, the lagoon sites surveyed for this study were in the path planned to be used to dredge a path for the barge to access the tower construction site. This is mentioned in the abstract, described in the introduction, referred to in the methods and results, and described again in the discussion. The dredging we are referring to is to remove benthic organisms to clear a path for the barge. That is the focus of the paper (the tower construction activities), and not other climate or local stressors, thus we only focus on this and wish not to speculate about other factors we do not have data to support. This is a communication piece specifically aimed at assessing potential impacts from the construction activities. We have added more information to the methods section to further clarify the proposed dredging activities. (lines 209-212)

The accuracy of the resulting methods and errors for the 3D reconstructions are all provided in the first paragraph of the results section. These are standard reporting values for structure-from-motion photogrammetry data products and are consistent with other publications using this remote sensing tool. We specifically reference other studies published in the Remote Sensing journal that use the same 3D approach.

Minor and Specific Comments:

Line 131: What do you mean by 3D photogrammetry techniques? Details and more examples are needed.

The technique is described in detail in the introduction with references. We have added additional details to the methods section to clarify the key components included in the training. (lines 146-149)

Line 138-139: No information up to now about these sites. Very vague.

More information about the sites has been added to the introduction (lines 138-148) and the methods section (lines 180-206)

Line 140: Why one representative?

Only one representative plot was used for analyses of the benthic habitat because each community member conducted a 3D survey for each of the three survey locations (Tower Footings Plot, Lagoon Plot 1, and Lagoon Plot 2). Thus, we obtained multiple replicate surveys for each survey site, but only one is needed to conduct the analyses since the same plot was surveyed by each individual only for training purposes. We revised this sentence for clarity.

Line 160: Citation for the software.

The software is cited on line 255; “(Agisoft LLC, St. Petersburg, Russia)”

Line 180: Shannon diversity index needs citation.

A citation has been added for the mention of this index.

Line 190: m2 area????

This has been revised to “m²”, as we are referring to the area of each live rock feature.

A small map of the island of Tahiti has been added to show the location of Teahupoo.

Line 194: covers is correct.

“Covers” has been changed to “were conducted”.

Line 194-195: The sentence has two verbs. Rewrite it, please.

As mentioned above, we have revised this sentence to use a past tense verb “conducted” to clarify that we used three survey locations for training and analysis of the reef habitat.

Line 197: These what? Images?

This sentence has been moved to the start of the results section to clarify we are referring to the three survey plots used for the analysis.

Line 205: “A high value of species richness” is a too general sentence. Be specific.

This sentence has been revised to, “The highest value of species richness was observed at the Tower Footing location.”

Figure 2a and b: The worst choice for selecting color.

The color palette used for this figure is a color-blind palate available in the ggplot package. We use this color to ensure all readers can clearly interpret the figure.

Our lab recently published a paper on engaging and supporting citizen science (Kapono et al. 2023), which is referenced in this manuscript. Based on our work in this area, specifically using 3D photogrammetry for citizen science, we are qualified to speak on the success of the training and ability to train the community members to successfully create 3D habitat maps in a short time. We have also provided details on the time required to complete all training components in the introduction. We have also taken other reviewers’ suggestions and placed this paragraph under the “Conclusion” section, where it is appropriate for us to provide a qualitative perspective on the success of the citizen science efforts for this project.

Reviewer 4 Report

Comments and Suggestions for Authors

Dear authors,

I read your article carefully. Some parts of the text need to be corrected according to the template; I marked these one by one on the PDF.

I also marked any grammatical errors I could see.

Again, I suggested making a few sentences more understandable; it's up to you.

My suggestion for the work area in Figure 1 is to add the Tahiti map to the upper left corner (I made it as an example and will add it). You also showed your work areas on the satellite image. Add information about which image this is. Also, include the coordinates of your study area.

Comments for author File: Comments.zip

Comments on the Quality of English Language

There were minor grammatical mistakes. I marked the ones I could see. Again, I suggested making a few sentences more understandable.

Author Response

Reviewer 4:

I read your article carefully. Some parts of the text need to be corrected according to the template; I marked these one by one on the PDF. I also marked any grammatical errors I could see. Again, I suggested making a few sentences more understandable; it's up to you. My suggestion for the work area in Figure 1 is to add the Tahiti map to the upper left corner (I made it as an example and will add it). You also showed your work areas on the satellite image. Add information about which image this is. Also, include the coordinates of your study area.

All suggested revisions in the PDF you provided have been incorporated into the manuscript, and we thank you for this input. The only change we did not make was citing the first sentence of the introduction. This is a general and well-known information about coral reefs and should not require a citation for this commonly known description. We have also revised Figure 1 to provide an inset map of Tahiti as well as coordinates. We revised the figure legend to clarify the sources of the orthoimages used in the figure.