Microplastics as Emerging Contaminants: Challenges in Inland Aquatic Food Web

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript titled "Microplastics as Emerging Contaminants: Challenges in Inland Aquatic Food Web" provides a comprehensive overview of the sources, distribution, and ecological impacts of microplastics in freshwater ecosystems. The authors have done an excellent job in consolidating current knowledge on the topic and highlighting the potential risks to human health through the consumption of microplastic-contaminated fish. The review is well-structured and covers a wide range of aspects related to microplastic pollution, making it a valuable contribution to the field.

 

Strengths

-          Comprehensive Coverage: The manuscript covers a broad spectrum of topics related to microplastic pollution, including sources, distribution, persistence, and ecological consequences. This holistic approach provides a thorough understanding of the issue.

-          Detailed Literature Review: The authors have conducted an extensive literature review, citing numerous studies and reports to support their arguments. This adds credibility and depth to the manuscript.

-          Clear Objectives: The objectives of the study are clearly stated, focusing on the impact of microplastics on the aquatic food web and human health. This clarity helps in understanding the scope and significance of the research.

-          Relevant Figures and Tables: The inclusion of figures and tables enhances the readability and comprehension of the data presented. The visual aids effectively illustrate the flow of microplastics in the aquatic food chain and their impacts on various organisms.

-          Practical Recommendations: The manuscript provides practical recommendations and policies for minimizing microplastic pollution in inland waters. These suggestions are actionable and could guide future research and policy-making.

Weaknesses

Repetition and Redundancy: Some sections of the manuscript contain repetitive information, which could be streamlined for better flow and readability. For example, the introduction and the section on the impact of microplastics on fish overlap in content.

Lack of Quantitative Data: While the manuscript provides a qualitative overview, it could benefit from more quantitative data and statistical analysis to support the findings. This would strengthen the arguments and provide a more robust basis for the conclusions.

Methodology Details: The methodology section could be more detailed. Specifically, the criteria for selecting the literature and the methods used for data extraction and analysis could be elaborated further.

Citation Consistency: There are inconsistencies in the citation format throughout the MS. Also, some references are cited in the text but not listed in the reference section, and vice versa. Ensuring consistency in citation would enhance the manuscript's professionalism.

Grammatical Errors: The manuscript contains several grammatical errors and awkward phrasing, which can distract from the content. A thorough proofreading is recommended to improve the overall quality of the writing.

The primary aim of this study is to review the impact of microplastics in inland waters. However, several sections, including 5.1 (Impacts on Plankton), 5.2 (Impact on Aquatic Plants), 5.3 (Impact on Benthic Invertebrates), and 5.4 (Impact on Fish), contain a significant number of examples and discussions related to marine ecosystems rather than inland waters. This discrepancy dilutes the focus of the manuscript and may confuse readers.

Required Revisions

-          Line 7 and 10: Font size of ‘India’ should be edited.

-          Line 42: "Infact, it is also seen that" should be "In fact, it is also seen that".

-          Line 96-97: "MPs of fibres and fragments type with 800−1600 μm 800−1600 μm size" should be "MPs of fiber and fragment types with sizes of 800−1600 μm 800−1600 μm".

-          L107-109 should be edited as 'Rather, these water bodies might be facing more catastrophic impacts than marine environments, as rivers are considered gateways of plastic debris to the oceans.' Additionally, ensure that common nouns such as 'river' and 'ocean' are not capitalized unless they are part of a proper noun.

-          The title on line 128 (4. Methodology applied and analysis of literature) and subtitle on line 129 (4.1. Methodology followed) should be revised.

-          L151: 'Figure 1' should be in parentheses for consistency with standard academic formatting. It should read: '(Figure 1)'. Additionally, ensure that all figures and tables are consistently referenced in this manner throughout the manuscript.

-          Throughout the manuscript, ensure consistent formatting for subtitles. Currently, some subtitles end with a colon, while others do not. To maintain consistency, it is recommended to remove the colon from all subtitles.

-          L188-192 is too long.

-          Line 194: "Upon arrival of this xenobiotic compounds (MPs) in the aquatic ecosystems" should be "Upon the arrival of these xenobiotic compounds (MPs) in aquatic ecosystems".

-          Line 195: "The micro-plastics negatively impacts the aquatic organisms" should be "Microplastics negatively impact aquatic organisms".

-          What is the Ref. of L218-220?

-          L199-202 should be edited; grammatical errors.

-          L207-19: The titles and subtitles of sections 5 and 5.1 are '5. Impact of Microplastics in Inland Aquatic Ecosystems' and '5.1. Impacts on Plankton,' respectively. However, many of the examples discussed in section 5.1 pertain to the effects of microplastics on marine plankton rather than inland plankton. This discrepancy is also observed in other sections, where the focus is more on marine creatures than inland organisms.

-          The primary aim of this study is to review the impact of microplastics in inland waters. However, several sections, including 5.1 (Impacts on Plankton), 5.2 (Impact on Aquatic Plants), 5.3 (Impact on Benthic Invertebrates), and 5.4 (Impact on Fish), contain a significant number of examples and discussions related to marine ecosystems rather than inland waters. This discrepancy dilutes the focus of the manuscript and may confuse readers. To align the content more closely with the study's objectives, it is recommended to:

1) Focus on Inland Waters: Revise the sections to include more examples and studies specifically addressing the impacts of microplastics on inland aquatic ecosystems. Ensure that the discussions and examples are relevant to rivers, lakes, and other freshwater bodies.

2) Remove or Minimize Marine Examples: If examples from marine ecosystems are included, clearly distinguish them from inland examples and explain their relevance to the overall discussion. Consider moving marine-focused content to an appendix or separate section if it is deemed necessary.

3) Consistency: Ensure that the titles, subtitles, and content of each section are consistent with the study's aim. This will help maintain a clear and coherent narrative throughout the manuscript.

-           

-          Line 243-246: "the rough sides of the plant surfaces through electrostatic forces and plant surface with the periphytic layer absorb more MPs due to higher retention of the microplastics with increased viscosity than the bare plant surfaces" should be "the rough sides of plant surfaces through electrostatic forces, and plant surfaces with a periphytic layer absorb more MPs due to higher retention of microplastics with increased viscosity than bare plant surfaces".

-          Line 241-242: "the MPs mediated oxidative stress, immunological disorder, impairment of the reproduction and retired developmental growth in decapod crustaceans" should be "MP-mediated oxidative stress, immunological disorders, impairment of reproduction, and retarded developmental growth in decapod crustaceans".

-          Lines 314-316 should be revised for clarity and grammatical correctness. The sentence can be rephrased as: 'Whether through direct ingestion or trophic transfer, microplastics (MPs) enter the fish body and accumulate in various organs, affecting the entire biological system. This accumulation can retard fish growth and health, and ultimately reduce the desired yield or production from aquatic systems.

-

 

Tables

-          There is no reference to Table 1 in the text. Please ensure that all tables are appropriately cited within the manuscript to provide context and relevance for the reader.

-          In Table 2, the 'Sl. No.' column is not necessary and can be removed to simplify the table. Additionally, the locations 'Southern and Northern Shores,' 'St. Lawrence River,' and 'Humber River' should specify the countries to which they belong for better context and clarity.

-           

Figures

-          Figure 2: L203: ‘Fow of microplastic’ should be edited as ‘Flow of microplastic’. Also this figure requires significant improvement in its design and presentation. The current figure appears amateurish and primitive, which detracts from the professionalism of the manuscript. Additionally, the title of the figure is too long and could be more concise.

Comments on the Quality of English Language

Needs major revision. Detailed required revisions are provided in the Review Report for the authors.

Author Response

The authors are thankful for the constructed suggestion by the esteemed reviewer and the necessary changes were made in the MS as per the suggestion. Most of the marine references are removed from the MS and more 12 freshwater references were added in the MS.

Required Revisions

Comments	Reply to the comments
Line 7 and 10: Font size of ‘India’ should be edited	We are thankful for the suggestion and necessary changes were made in the MS.
Line 42: "Infact, it is also seen that" should be "In fact, it is also seen that".	We are thankful for the suggestion and necessary changes were made in the MS.
Line 96-97: "MPs of fibres and fragments type with 800−1600 μm 800−1600 μm size" should be "MPs of fiber and fragment types with sizes of 800−1600 μm 800−1600 μm".	The sentence has been modified in the revised MS.
L107-109 should be edited as 'Rather, these water bodies might be facing more catastrophic impacts than marine environments, as rivers are considered gateways of plastic debris to the oceans.' Additionally, ensure that common nouns such as 'river' and 'ocean' are not capitalized unless they are part of a proper noun.	The sentence has been modified in the revised MS.
The title on line 128 (4. Methodology applied and analysis of literature) and subtitle on line 129 (4.1. Methodology followed) should be revised.	Necessary changes were made in the MS.
'Figure 1' should be in parentheses for consistency with standard academic formatting. It should read: '(Figure 1)'. Additionally, ensure that all figures and tables are consistently referenced in this manner throughout the manuscript.	Necessary changes were made in the MS.
Throughout the manuscript, ensure consistent formatting for subtitles. Currently, some subtitles end with a colon, while others do not. To maintain consistency, it is recommended to remove the colon from all subtitles	Necessary changes were made in the MS
L188-192 is too long.	The sentence has been restructured
Line 194: "Upon arrival of this xenobiotic compounds (MPs) in the aquatic ecosystems" should be "Upon the arrival of these xenobiotic compounds (MPs) in aquatic ecosystems	Necessary changes were made in the MS
Line 195: "The micro-plastics negatively impacts the aquatic organisms" should be "Microplastics negatively impact aquatic organisms".	Necessary changes were made in the MS
What is the Ref. of L218-220?	Reference has been added
L199-202 should be edited; grammatical errors	Necessary changes were made in the MS
L207-19: The titles and subtitles of sections 5 and 5.1 are '5. Impact of Microplastics in Inland Aquatic Ecosystems' and '5.1. Impacts on Plankton,' respectively. However, many of the examples discussed in section 5.1 pertain to the effects of microplastics on marine plankton rather than inland plankton. This discrepancy is also observed in other sections, where the focus is more on marine creatures than inland organisms.	Most of the marine references were deleted and only freshwater information were discussed
The primary aim of this study is to review the impact of microplastics in inland waters. However, several sections, including 5.1 (Impacts on Plankton), 5.2 (Impact on Aquatic Plants), 5.3 (Impact on Benthic Invertebrates), and 5.4 (Impact on Fish), contain a significant number of examples and discussions related to marine ecosystems rather than inland waters. This discrepancy dilutes the focus of the manuscript and may confuse readers. To align the content more closely with the study's objectives, it is recommended to: 1) Focus on Inland Waters: Revise the sections to include more examples and studies specifically addressing the impacts of microplastics on inland aquatic ecosystems. Ensure that the discussions and examples are relevant to rivers, lakes, and other freshwater bodies. 2) Remove or Minimize Marine Examples: If examples from marine ecosystems are included, clearly distinguish them from inland examples and explain their relevance to the overall discussion. Consider moving marine-focused content to an appendix or separate section if it is deemed necessary. 3) Consistency: Ensure that the titles, subtitles, and content of each section are consistent with the study's aim. This will help maintain a clear and coherent narrative throughout the manuscript.	Most of the marine references were deleted and only freshwater information were discussed.
Line 243-246: "the rough sides of the plant surfaces through electrostatic forces and plant surface with the periphytic layer absorb more MPs due to higher retention of the microplastics with increased viscosity than the bare plant surfaces" should be "the rough sides of plant surfaces through electrostatic forces, and plant surfaces with a periphytic layer absorb more MPs due to higher retention of microplastics with increased viscosity than bare plant surfaces".	Necessary changes were made in the MS
Line 241-242: "the MPs mediated oxidative stress, immunological disorder, impairment of the reproduction and retired developmental growth in decapod crustaceans" should be "MP-mediated oxidative stress, immunological disorders, impairment of reproduction, and retarded developmental growth in decapod crustaceans".
Lines 314-316 should be revised for clarity and grammatical correctness. The sentence can be rephrased as: 'Whether through direct ingestion or trophic transfer, microplastics (MPs) enter the fish body and accumulate in various organs, affecting the entire biological system. This accumulation can retard fish growth and health, and ultimately reduce the desired yield or production from aquatic systems.	Necessary changes were made in the MS
Tables -          There is no reference to Table 1 in the text. Please ensure that all tables are appropriately cited within the manuscript to provide context and relevance for the reader. -          In Table 2, the 'Sl. No.' column is not necessary and can be removed to simplify the table. Additionally, the locations 'Southern and Northern Shores,' 'St. Lawrence River,' and 'Humber River' should specify the countries to which they belong for better context and clarity.	Table-1 now added in the text.         In Table-2- Sl. No – removed
Figures -          Figure 2: L203: ‘Fow of microplastic’ should be edited as ‘Flow of microplastic’. Also this figure requires significant improvement in its design and presentation. The current figure appears amateurish and primitive, which detracts from the professionalism of the manuscript. Additionally, the title of the figure is too long and could be more concise.	Figure-2 has been modified and a new improved figure has been added in the MS.

 

 

 

 

 

 

 

 

 

 

Reviewer 2 Report

Comments and Suggestions for Authors

I have reviewed the manuscript, and in my best judgement, there is a need for some important revisions.

1. The first sentence in the manuscript (MS) requires a citation. How did you know that 'Plastics are the most versatile and omnipresent material in the world'? Secondly, it is important for the authors to include some discussion about how the water chemistry and local hydrodynamics in freshwater ecosystems are different from those of marine ecosystems and how these processes influence the distribution and impacts of MPs. This will give some depth to the choice of freshwater, rather than a superficial mention. The link below could be helpful: https://www.sciencedirect.com/science/article/pii/S0921344924001733

2. Lines 42-44: Citation is required

3. Lines 56-58: Delete the hyperlink and include a proper citation.

4. Lines 60-62: The definition of microplastics is incorrect. MPs are not just particles but 'plastic' particles.

5. Lines 67-69 is a repetition of lines 63-66. Please harmonise them.

6. Line 72: The authors did not justify the statement that 'MP sources are not well characterised. What is the use of that statement? Neither did the authors provide any characterisation different from already known sources. Please justify or delete the statement.

7. Lines 107-109 need to be restructured to be meaningful.

8. Lines 111-114: The statement here is contradictory and has grammatical error.

9. Remove the gridlines in Figure 1 for clarity.

10. Line 203: Typographic error 'Fow'

11. Line 212: Typographic error 'inhabit' should be 'inhibit'

12. Lines 361-364: Citation required.

Comments on the Quality of English Language

The article needs English editing as there are many grammatical errors and sentence construction issues in the manuscript.

Author Response

The authors are thankful for the constructed suggestion by the esteemed reviewer and the necessary changes were made in the MS as per the suggestion.

Comments	Reply to the comments
1. The first sentence in the manuscript (MS) requires a citation. How did you know that 'Plastics are the most versatile and omnipresent material in the world'? Secondly, it is important for the authors to include some discussion about how the water chemistry and local hydrodynamics in freshwater ecosystems are different from those of marine ecosystems and how these processes influence the distribution and impacts of MPs. This will give some depth to the choice of freshwater, rather than a superficial mention. The link below could be helpful: https://www.sciencedirect.com/science/article/pii/S0921344924001733	We are thankful for the suggestion and necessary changes were made in the MS.
2. Lines 42-44: Citation is required	As per the suggestion, reference added
3. Lines 56-58: Delete the hyperlink and include a proper citation.	As per the suggestion, the hyperlink was deleted
4. Lines 60-62: The definition of microplastics is incorrect. MPs are not just particles but 'plastic' particles.	As per the suggestion, necessary changes were made
5. Lines 67-69 is a repetition of lines 63-66. Please harmonise them.	As per the suggestion, necessary changes were made
6. Line 72: The authors did not justify the statement that 'MP sources are not well characterised. What is the use of that statement? Neither did the authors provide any characterisation different from already known sources. Please justify or delete the statement.	The line has been restructured
7. Lines 107-109 need to be restructured to be meaningful.	As per the suggestion, necessary changes were made
8. Lines 111-114: The statement here is contradictory and has grammatical error.	The sentence has been restructured.
9. Remove the gridlines in Figure 1 for clarity.	The gridlines were removed
10. Line 203: Typographic error 'Fow'	necessary changes were made
11. Line 212: Typographic error 'inhabit' should be 'inhibit'	necessary changes were made
12. Lines 361-364: Citation required.	References added

 

Reviewer 3 Report

Comments and Suggestions for Authors

This is a paper that could be tremendously useful for generating consensus and influencing the next steps for understanding and living with MP pollution. However, more relevant and current information needs to be provided. There have been several papers that are not included here, and as a review article, it is largely incomplete. With the addition of more new and emerging research, this could be an excellent paper. 

Comments on the Quality of English Language

It is unclear whether this is an issue with the copyediting or the original text - I have never received a pre-formatted paper for review like this. I'm not sure why it has gotten to that point. There are dozens or grammatical errors throughout and several typos where words are combined where a space is needed. I'm not able to support publication of something that, in its current form, is not going to be received by a scientific audience as credible - due not to the content, but the presentation. 

Author Response

 

Comments	Reply to the comments
This is a paper that could be tremendously useful for generating consensus and influencing the next steps for understanding and living with MP pollution. However, more relevant and current information needs to be provided. There have been several papers that are not included here, and as a review article, it is largely incomplete. With the addition of more new and emerging research, this could be an excellent paper.	The authors are thankful for the suggestion of the esteemed reviewer, and 12 new references are now discussed in the MS. It is not possible to add all the references, we have added all recent and most relevant references in the article in the revised MS.
Comments on the Quality of English Language It is unclear whether this is an issue with the copyediting or the original text - I have never received a pre-formatted paper for review like this. I'm not sure why it has gotten to that point. There are dozens or grammatical errors throughout and several typos where words are combined where a space is needed. I'm not able to support publication of something that, in its current form.	We have restructured the sentences in the whole MS and taken care that words should not be joined together.

 

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The revised manuscript titled "Microplastics as Emerging Contaminants: Challenges in Inland Aquatic Food Web" demonstrates significant improvements compared to the original submission. The authors have addressed the major concerns raised during the initial review, and the revised version aligns more closely with the intended scope of the study. The revised manuscript focuses more effectively on microplastics in freshwater ecosystems, providing a clear and relevant discussion of their sources, distribution, and ecological impacts. The authors have successfully incorporated additional references that enhance the comprehensiveness and scientific foundation of the manuscript. Furthermore, the language has been improved significantly, and the grammatical issues noted in the original version have been corrected, resulting in a more professional and polished presentation. Overall, the revised manuscript effectively addresses the concerns raised and meets the standards for publication.

Author Response

Comment:

The revised manuscript titled "Microplastics as Emerging Contaminants: Challenges in Inland Aquatic Food Web" demonstrates significant improvements compared to the original submission. The authors have addressed the major concerns raised during the initial review, and the revised version aligns more closely with the intended scope of the study. The revised manuscript focuses more effectively on microplastics in freshwater ecosystems, providing a clear and relevant discussion of their sources, distribution, and ecological impacts. The authors have successfully incorporated additional references that enhance the comprehensiveness and scientific foundation of the manuscript. Furthermore, the language has been improved significantly, and the grammatical issues noted in the original version have been corrected, resulting in a more professional and polished presentation. Overall, the revised manuscript effectively addresses the concerns raised and meets the standards for publication.

 

Reply:

The authors express their gratitude to the esteemed reviewer for the valuable suggestions that helped improve the manuscript. We sincerely appreciate and acknowledge the reviewer’s contribution.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript still requires some revision. The authors have not fully addressed the initial comments.

1. Table 1 is unnecessary and should be removed. It is merely a repetition of what has already been stated in the previous section and does not provide any new information.

2. Lines 102-107 read like a copy and paste from a textbook. Phrases like'such a review' and 'the review can' indicate that the authors are not referring to their own review but a text from somewhere else. Please recast.

3. The methodology section should be written in reported speech. The process has already been carried out, and this should reflect in the report. For example, 'the process begins' should be 'the process began' etc.

4. Line 62: I still do not understand why the authors state that 'the sources of MPs are not well defined' and yet they fail to provide any reason for this. Please delete the statement.

 

Author Response

Reviewer -2

The authors are thankful for the constructed suggestion by the esteemed reviewer and the necessary changes were made in the MS as per the suggestion.

 

Comment-1

Table 1 is unnecessary and should be removed. It is merely a repetition of what has already been stated in the previous section and does not provide any new information

Reply :

Table 1 is deleted as per the suggestion and all the tables were renumbered

 

Comment-2

Lines 102-107 read like a copy and paste from a textbook. Phrases like 'such a review' and 'the review can' indicate that the authors are not referring to their own review but a text from somewhere else. Please recast

Reply:

The objective portion was rewritten as per the suggestion

Comment-3

The methodology section should be written in reported speech. The process has already been carried out, and this should reflect in the report. For example, 'the process begins' should be 'the process began' etc.

Reply:

The methodology section has been reframed to reported speech, as per the suggestion

 

Comment-4

Line 62: I still do not understand why the authors state that 'the sources of MPs are not well defined' and yet they fail to provide any reason for this. Please delete the statement.

Reply:

The sentence was deleted from MS as per the suggestion