Presence, Spatial Distribution, and Characteristics of Microplastics in Beach Sediments Along the Northwestern Moroccan Mediterranean Coast

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear author/authors,

I am pleased to review the manuscript (MS) titled “Presence, Spatial Distribution and Characteristics of Microplastics in Beach Sediments along the Northwestern Moroccan Mediterranean Coast”. In general, the manuscript contains original and valuable research information. The manuscript is well written and organized, obtaining relevant results that focused on quantifying and characterizing microplastics in sand collected from beach sediments along the Northestern Moroccan Mediterranean Coast. However, some content is necessary to be addressed. The manuscript could be reconsidered after carefully addressing the following issues and also looking into the manuscript.

 

Comment: The objective is not clearly stated. Please provide a clear statement of objective.

Comment: Section 2-study area should be under the Materials and Methods section.

Comment: Section 3-Method: Methodology seems redundant. Please organize and write the methods with subheadings.

Comment: Results and Discussion: Did you measure the ecological risk assessment of microplastics?

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The research could be expressed more clearly with better English.

Author Response

Dear Reviewer 1,

Thank you for your valuable comments and suggestions. We have taken all of them into account in the revised version of the manuscript. Our responses to your comments and suggestions are provided below:

Comment: The objective is not clearly stated. Please provide a clear statement of objective.

Response:

• DONE. A clear statement of the objective of the study has been added to the manuscript in the final part of the Introduction.

Comment: Section 2-study area should be under the Materials and Methods section.

Response:

• DONE. The description of the study area has been moved to the ‘Materials and Methods’ section, as you recommended.

Comment: Section 3-Method: Methodology seems redundant. Please organize and write the methods with subheadings.

Response:

• DONE. The methodology has been improved with more detailed explanations, reorganized, and rewritten with subheadings to make it easier for readers to understand.

Comment: Results and Discussion: Did you measure the ecological risk assessment of microplastics?

Response:

• In this study, we did not assess the ecological risk of microplastics, as it was not part of our main objective. The focus of this study is to determine the prevalence and spatial distribution of microplastic debris along the northwest Mediterranean coast of Morocco. However, in future research, we plan to examine the ecological risks associated with microplastics. In this paper we added only some indications.....

Reviewer 2 Report

Comments and Suggestions for Authors

Introduction:
A paragraph explaining the link between the problem of microplastic pollution and the area studied is missing. In fact, we need to justify the interest of the project here, apart from a simple description of its condition.

Study site:
Why were these 14 beaches chosen? Are they representative of the habitats encountered? If so, in what proportions?

Methods:
Why a sampling campaign in November? Given that the samples are taken in the first 5 cm, it's possible that the composition is affected by environmental conditions. Have there been storms before? What would be the results if sampling had been carried out at other times of the year?
The relevance of non-parametric tests is questionable, given the low n of the samples. An ANOVA, even with a non-normal distribution, would be more powerful.

 

Results and Discussion
Comparisons of MPs with other sites are not justified, only one reference is cited. For each comparison, it would be necessary to detail how it is comparable, and whether the causes are identical, such as the presence of tourists.
As for the presence of restaurants, which would explain the presence of PMs, the authors should go into more detail. What percentage of the coastline is occupied by restaurants compared with the reference cited, etc.?
Can we really compare the densities of tourists visiting the beaches studied with those cited in the references? We'd need to go into more detail.
Strong CVs on microplastic type data show wide variations. How to explain the interpretation of the data. We need to put the results into perspective, given the low sample size (one sampling campaign with 3 replicates). We need to put things into perspective.

All the findings need to be put into perspective with the sampling plan. What's more, the authors merely describe the results and compare them with data in the literature. The article would gain a lot if the authors put the results obtained into perspective with the impacts on littoral and marine flora and fauna. We need to go beyond the descriptive stage.

 

Author Response

Dear Reviewer 2,

Thank you for your valuable comments and suggestions. We have taken all of them into account in the revised version of the manuscript. Our responses to your comments and suggestions are provided below:

Introduction:
A paragraph explaining the link between the problem of microplastics pollution and the area studied is missing. In fact, we need to justify the interest of the project here, apart from a simple description of its condition.

Response:

• A paragraph explaining the link between the problem of microplastic pollution and the study area has been added, and a clear statement of the purpose and significance of the study has been provided.

Study site:

Why were these 14 beaches chosen? Are they representative of the habitats encountered? If so, in what proportions?

Response:

• Done. The criteria considered for the selection of the beaches have been mentioned in the Study Area section.

Methods:
Why a sampling campaign in November? Given that the samples are taken in the first 5 cm, it's possible that the composition is affected by environmental conditions. Have there been storms before? What would be the results if sampling had been carried out at other times of the year?

Response:

• DONE. The rationale for conducting the sampling campaign in November has been provided in the manuscript. This is explained by the fact that the fieldwork was carried out in November 2021, before the arrival of relevant winter rains and marine storms that could influence the abundance and distribution of plastic debris in beach sediments. Therefore, the conditions were favorable for sampling.

The relevance of non-parametric tests is questionable, given the low n of the samples. An ANOVA, even with a non-normal distribution, would be more powerful.

Response:

• An ANOVA with a non-normal distribution has been conducted and included in the manuscript.

Results and Discussion

Comparisons of MPs with other sites are not justified, only one reference is cited. For each comparison, it would be necessary to detail how it is comparable, and whether the causes are identical, such as the presence of tourists.

Response:

• The comparisons with other sites have been justified in the manuscript. We clarified that the comparisons were based on the use of the same methodological protocols for sampling and laboratory analysis of microplastics, ensuring consistency between studies, in addition to considering potential influencing factors such as tourist activities and fishing.

As for the presence of restaurants, which would explain the presence of MPs, the authors should go into more detail. What percentage of the coastline is occupied by restaurants compared with the reference cited, etc.?

Response:

• Due to the lack of information regarding the percentage of coastline occupied by restaurants in the area cited, the sentence has been removed.

Can we really compare the densities of tourists visiting the beaches studied with those cited in the references? We'd need to go into more detail.

Response:

• The primary purpose of our reference to other studies was not to compare the study area with other sites around the world, but rather to provide examples of some studies that have found a strong correlation between the prevalence of microplastics and tourist activities. The paragraph in the paper has been revised to better clarify the meaning of this point.

Strong CVs on microplastics type data show wide variations. How to explain the interpretation of the data. We need to put the results into perspective, given the low sample size (one sampling campaign with 3 replicates). We need to put things into perspective.

Response:

• The interpretation of the results has been put into perspective accordingly.

All the findings need to be put into perspective with the sampling plan. What's more, the authors merely describe the results and compare them with data in the literature. The article would gain a lot if the authors put the results obtained into perspective with the impacts on littoral and marine flora and fauna. We need to go beyond the descriptive stage.

Response:

• Done. The results have been analyzed in the context of their impacts on coastal and marine organisms, providing a deeper understanding of their ecological significance.

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Comments for Authors

This manuscript has improved over the original version. The authors also note their response to most of the suggested changes. Thank you! Though one of my comments wasn’t addressed, the authors explained these. I am satisfied. However, some attention should be given, especially to discussion and reference formatting, before accepting the manuscript.

Author Response

Dear Reviewer 1,

Thank you for your valuable comments and suggestions. We have taken all of them into account in the revised version of the manuscript. Our responses to your comments and suggestions are provided below:

Comment: This manuscript has improved over the original version. The authors also note their response to most of the suggested changes. Thank you! Though one of my comments wasn’t addressed, the authors explained these. I am satisfied. However, some attention should be given, especially to discussion and reference formatting, before accepting the manuscript. 

Response:

• DONE. To further elucidate the results, supplementary paragraphs have been added to the discussion section. In addition, the references have been formatted in accordance with established standards.

Reviewer 2 Report

Comments and Suggestions for Authors

Corrections requested during the first session have been taken into account.

I have no major comments on English. It seems to me, however, that Latin abbreviations such as i.e., via should be italicized.

Author Response

Dear Reviewer 2,

Thank you for your valuable comments and suggestions. We have taken all of them into account in the revised version of the manuscript. Our responses to your comments and suggestions are provided below:

Comment: Corrections requested during the first session have been taken into account. I have no major comments on English. It seems to me, however, that Latin abbreviations such as i.e., via should be italicized.  

Response:

• DONE. Latin abbreviations have been formatted in italics.