Baseline Marine Litter Surveys along Vietnam Coasts Using Citizen Science Approach

Round 1

Reviewer 1 Report

This paper compares the results of citizen science at the sites selected according to the criteria, and was written scientifically, logically, and appropriately as a baseline study in Vietnam. There are some corrections, but it can be published with minor revision.

1. Please redraw Figure 1 with a higher resolution. Provide the GPS information of each site. (The supplementary link was incorrect and could not be verified.)
2. There are several criteria for selecting sites, and a supplementary explanation is needed on how the results change depending on the criteria. Are rural and urban standards set at the population level?
3. In Table 1, it is unclear who is concerned about plastic waste by awareness.
Page 10: “In addition, the mean density of litter was approximately ten times higher in non-tourism areas than in tourism areas.” Is it correct expression? Figure 2 shows no ten-time difference.
4. There are too many typos and styles to be corrected.
5. Page 15: "New country-specific marine litter categories". If there is a rationale for organizing the country-specific items, please suggest them.

Author Response

Response to Reviewer 1 Comments

Point 1: Please redraw Figure 1 with a higher resolution. Provide the GPS information of each site. (The supplementary link was incorrect and could not be verified.).

Response 1: The authors team would thank the comments, we redrew Figure 1 with a higher resolution and provided the GPS information of each site. We sorried for the supplementary link; however, it will be updated when the paper is published.

Point 2: There are several criteria for selecting sites, and a supplementary explanation is needed on how the results change depending on the criteria. Are rural and urban standards set at the population level?

Response 2: The author team thanks the reviewer's comments; however, we thought it was not neccessary to add a supplementary explanation for this since they are relatively easy to understand in the criteria and only need to select the beaches that fit these criteria. The rural and urband standars set based on administrative division of local authority.

Point 3: In Table 1, it is unclear who is concerned about plastic waste by awareness.

Page 10: “In addition, the mean density of litter was approximately ten times higher in non-tourism areas than in tourism areas.” Is it correct expression? Figure 2 shows no ten-time difference.

Response 3: Thank you for your comment, we added information of who is concerned about plastic waste by awareness (local residents and tourists).

And we revised Figure 2 in page 10 along with the text to be more approriate, we appologize for this mistake.

Point 4: There are too many typos and styles to be corrected

Response 4: Thank you for your suggestion. The authors have corrected the typing mistakes in the paper

Point 5: Page 15: "New country-specific marine litter categories". If there is a rationale for organizing the country-specific items, please suggest them.

Response 5: Thank you for your suggestion. We introduced the “New country-specific marine litter categories” in Supplementary 1.

Reviewer 2 Report

Comments to the authors

The manuscript entitled “Baseline marine litter surveys along Vietnam coasts using citizen science approach” aimed to quantify and characterize marine litter using the GESAMP marine litter monitoring guideline.

The manuscript is easy to read and the material and Methods section has not been well organized.

There was no page number and line number.

I encourage more and in detailed discussion of effects of anthropogenic activities on the results of this study. Such as data for fisheries and aquaculture activities, population and… in the study areas.

Introduction Section: “Due to its persistence, it takes tens to hundreds of years to remove or degrade marine litter in the natural environment.” Put the citation/s.

Section Study area; part6: check “If the survey is at only only one coastal site in a location, we choose either”

Page 15, line 11: check “per cent”.

Section 3.2. Comparisons of marine litter compositions, quantities and distribution among locations; line 5: “In some cases, … have poor public awareness.” How the authors measure poor public awareness? Or cite the statement.

“However, the … that there is a trend towards lower debris in tourism areas.” Why? Due to clean up activities or …? Please state.

Author Response

Response to Reviewer 2 Comments

Point 1: The manuscript entitled “Baseline marine litter surveys along Vietnam coasts using citizen science approach” aimed to quantify and characterize marine litter using the GESAMP marine litter monitoring guideline.

Response 1: Thank you for your suggestion, we revised the objective of this study.

Point 2: The manuscript is easy to read and the material and Methods section has not been well organized.

Response 2: The author team thanks the reviewer's comments; however, we are not sure what suggestion is being made. We have organised the methods into separate sections for study area, sampling methods, and data analysis. This seems like a sensible organisation; however we do welcome specific comments on this topic.

Point 3: There was no page number and line number.

Response 3: We thanks for your comment; we added page number and line number at first.

Point 4: I encourage more and in detailed discussion of effects of anthropogenic activities on the results of this study. Such as data for fisheries and aquaculture activities, population and… in the study areas.

Response 4: Thank you for your valuable comments. In the discussion, we did discuss the effects of anthropogenic activities on the results of this study; however, data for fisheries and aquaculture activities are very difficult to collect, and there is almost no announcement from the authorities. We will try to perfect for the following studies.

Point 5: Section Study area; part6: check “If the survey is at only only one coastal site in a location, we choose either”

Response 5: We revised the sentence.

Point 6: Page 15, line 11: check “per cent”.

Response 6: Thank you for your comment, we rechecked it.

Point 7: Section 3.2. Comparisons of marine litter compositions, quantities and distribution among locations; line 5: “In some cases, … have poor public awareness.” How the authors measure poor public awareness? Or cite the statement.

Response 7: Thank you for you comment, we did some interviews with local residents and tourists to measure their awareness of plastic waste in the area.

Point 8: “However, the … that there is a trend towards lower debris in tourism areas.” Why? Due to clean up activities or …? Please state.

Response 8: We thanks for your comment and we have made clarification at line 280-281

Reviewer 3 Report

The manuscript is well-organized, with well-developed sections and clearly explained methodology, therefore it is easy to understand. 

In Abstract and Tables 1. and 3. is stated that surveys were organized from September 2020 to January 2021, while in text is written that the locations were surveyed between July 2020 and January 2021, therefore it should be corrected.

Moreover, from the data presented in the manuscript, it can be concluded that each location was surveyed once (it should be stated in the text), therefore for future researches replicas should be considered in each location.

The authors should add some explanation, or data to the Table 1., regarding a number of people conducting surveys in different locations, considering the text line "In each location, at least two members of the experienced survey team and 6 to 10 local volunteers carried out the survey." Moreover, numbers should be listed in the same way throughout the text, either in numbers or words (for example 2 members and 6 volunteers, or two members and six volunteers).

There are minor grammatical errors that should be corrected and some of the words repeted twice (minor spell check required), while some of the cited references could be revised and replaced with current ones.

This manuscript confirmed that citizen science approach can be useful in collecting marine litter data, although there are some limitations that should be considered and improved in future researches.

The manuscript should be accepted after minor revision.

Author Response

Response to Reviewer 3 Comments

Point 1: In Abstract and Tables 1. and 3. is stated that surveys were organized from September 2020 to January 2021, while in text is written that the locations were surveyed between July 2020 and January 2021, therefore it should be corrected.

Response 1: Thank you for your suggestion, we revised the text accordingly.

Point 2: Moreover, from the data presented in the manuscript, it can be concluded that each location was surveyed once (it should be stated in the text), therefore for future researches replicas should be considered in each location.

Response 2: The author team thanks the reviewer's comments; and we confirmed it in the text.

Point 3: The authors should add some explanation, or data to the Table 1., regarding a number of people conducting surveys in different locations, considering the text line "In each location, at least two members of the experienced survey team and 6 to 10 local volunteers carried out the survey." Moreover, numbers should be listed in the same way throughout the text, either in numbers or words (for example 2 members and 6 volunteers, or two members and six volunteers)..

Response 3: We thanks for your comment; however, we explained the number of people conducting suveys in each location; therefore, we thought that it was not necessary to add this information in Table 1.

We corrected the way of number listed in the text .

Point 4: There are minor grammatical errors that should be corrected and some of the words repeted twice (minor spell check required), while some of the cited references could be revised and replaced with current ones.

Response 4: Thank you for your valuable comments. We corrected grammatical errors and repeted words.

We rechecked the cited references; however, we would love to keep them because they were suitable for citation in the manuscript.