Accuracy of a Simple Microplastics Investigation Method on Sandy Beaches

Round 1

Reviewer 1 Report

1. Why author did not perform a spectroscopic analysis to confirm the types of MPs? 

2. It would be more interesting and meaningful if the MPs images were captured using a microscope such as a scanning electron microscope.

3. Line 242 - what is the mass of CaCl₂ being added?

4.  The methodology section is better to be written in the past tense.

5. Line 286 - why the author used plastic bags for storing and transportation of the MPs? Could it lead to contamination of the MP sample from the bags?

6. Lines 290-292 & 341-343. Rewrite these sentences

7. Some of the obtained data might be more attractive and valuable to readers if they are presented in tabular form.

Recommended to use the past tense in the methodology section and passive verbs.

Author Response

Please see an attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors reported a simple method for land survey, MPs sampling, MPs sorting, and MPs analysis using simple tools. There some questions need to be further considered.

(1) The authors reported the method based on the weight rather than the number of particles in this study. However, both parameters are important. Especially for environmental impact assessment, the number and size distribution are very important information.

(2) The authors reported the results of the heavy liquid sorting, distribution in depth et al.  However, all these results can be greatly different in different countries and different coastal areas. Especially, the authors only investigated limited sites in Japan.   

Author Response

Please see an attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear author

Congratulation for the approach and method proposed which provide a simple approach for citizen preoccupied by MPls presence on beach and coastal region. Then I insert directly in your manuscript some questions, suggestions. I invite you to consider them.

Comments for author File: Comments.pdf

Author Response

Please see an attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have made revisions according to my comments. It is acceptable for publication now.