Alien Macroalgal Rearrangement in the Soft Substrata of the Venice Lagoon (Italy): Impacts, Threats, Time and Future Trends

Round 1

Reviewer 1 Report

You can include recent references, do a larger search.
It can improve the description of how the research design was carried out, the questions, the hypotheses and the methods is not clear enough.

It is necessary to contrast the discussion with recent studies of the characteristics of the species and the impact or specific benefit mainly of the introduced species with greater mass.
What were the physicochemical conditions of their adaptation.

It is desirable to make a discussion from the impacts and ecosystem benefits and the importance of continuing to monitor, if there is a social effect on the population such as tourism.

Include a conclusion that considers the contribution and environmental public policies of the ecosystem.

Author Response

Comments and Suggestions for Authors

You can include recent references, do a larger search.
It can improve the description of how the research design was carried out, the questions, the hypotheses and the methods is not clear enough.
It is necessary to contrast the discussion with recent studies of the characteristics of the species and the impact or specific benefit mainly of the introduced species with greater mass.
What were the physicochemical conditions of their adaptation.

We have added an extensive general introduction on the alien species in the aquatic environments focusing of some invasive species and their impact from the environmental and economic point of view. Many references on the alien species have been added.

It is desirable to make a discussion from the impacts and ecosystem benefits and the importance of continuing to monitor, if there is a social effect on the population such as tourism.

In many parts of the text information on this topic was added.

Include a conclusion that considers the contribution and environmental public policies of the ecosystem.

It was done.

Reviewer 2 Report

The current manuscript entitled “Alien macroalgal rearrangement in the soft substrata of the Venice Lagoon (Italy). Impacts, threats and time trends.” by Sfriso et al. deals with a comprehensive overview of the problem of alien macroalgal rearrangement in the Venice Lagoon. The authors highlight the different types of macroalgae species that have invaded the lagoon and their impact on the local ecosystem. They also discuss the various factors that have contributed to the proliferation of these species, including climate change, nutrient pollution, and shipping activities. The problem taken by the authors is current and requires sustainable solutions. After a careful reading, I found this manuscript of good quality, however, certain improvements are required before it is considered by the Sustainability journal. I suggest a minor revision. My specific comments are:

1.      The English language of the manuscript should be scrutinized by a native speaker. The flow of reading is more passive where they can be just written directly without placing the main subject in end or between.

2.      Title: change it to: Alien macroalgal rearrangement in the soft substrata of the Venice Lagoon (Italy): Impacts, threats, and future trends

3.      Please consider rewriting the abstract more logically. A problem statement should be given at starting, followed by clear objectives, a brief method, major numerical results, their meaning, usefulness, and contribution of this work to current knowledge.

4.      Avoid placing keywords that already appeared in the title.

5.      Line 60: please replace “paper” with “study”. Same in other places.

6.      Figure 1: explain in the caption what the white dot means. Also, place a boundary around the study area.

7.      Too short paragraphs in the manuscript should be merged together to form big enough paragraphs (at least 150 words).

8.      Table 1: Please change the format according to the MDPI style. What does “???” mean in the first row?

9.      Change Tab to Tables and Fig to Figure.

10.   A conclusion section (200 words) should be added in order to summarize overall findings and suggest limitations/future needs of this study.

11.   Please consider eliminating outdated references and provide the latest (10-year) ones.

The English language of the manuscript should be scrutinized by a native speaker. The flow of reading is more passive where they can be just written directly without placing the main subject in end or between.

Author Response

All text additions and changes are shown in red.

Referee 2

Comments and Suggestions for Authors

The current manuscript entitled “Alien macroalgal rearrangement in the soft substrata of the Venice Lagoon (Italy). Impacts, threats and time trends.” by Sfriso et al. deals with a comprehensive overview of the problem of alien macroalgal rearrangement in the Venice Lagoon. The authors highlight the different types of macroalgae species that have invaded the lagoon and their impact on the local ecosystem. They also discuss the various factors that have contributed to the proliferation of these species, including climate change, nutrient pollution, and shipping activities. The problem taken by the authors is current and requires sustainable solutions. After a careful reading, I found this manuscript of good quality, however, certain improvements are required before it is considered by the Sustainability journal. I suggest a minor revision. My specific comments are:

1. The English language of the manuscript should be scrutinized by a native speaker. The flow of reading is more passive where they can be just written directly without placing the main subject in end or between.

         The English was revised by a person fluent in English and modified where necessary, according to the suggestion.

2. Title: change it to: Alien macroalgal rearrangement in the soft substrata of the Venice Lagoon (Italy): Impacts, threats, and future trends

We prefer to add “future” to the original title as in the text we have examined the temporal trends of the single species.

3. Please consider rewriting the abstract more logically. A problem statement should be given at starting, followed by clear objectives, a brief method, major numerical results, their meaning, usefulness, and contribution of this work to current knowledge.

The abstract was rewritten supplying an initial problem statement, objectives, results and consideration on their ecosystem impact.

4. Avoid placing keywords that already appeared in the title.

         OK, we have deleted “soft substrata” and “Lagoon of Venice”.

     5. Line 60: please replace “paper” with “study”. Same in other places.

         It was done.

6. Figure 1: explain in the caption what the white dot means. Also, place a boundary around the study area.

         It was done.

7. Too short paragraphs in the manuscript should be merged together to form big enough paragraphs (at least 150 words).

Where it was possible without weighing down the text, we have modified the text as suggested.

8. Table 1: Please change the format according to the MDPI style. What does “???” mean in the first row?

         We have replaced “???” with “unknown” and adjusted the format    according to the MDPI style.

9. Change Tab to Tables and Fig to Figure.

         It was done.

10. A conclusion section (200 words) should be added in order to summarize overall findings and suggest limitations/future needs of this study.

         It was inserted.

11. Please consider eliminating outdated references and provide the latest (10-year) ones.

        Some outdated references were deleted and others more recent were added.

Comments on the Quality of English Language

The English language of the manuscript should be scrutinized by a native speaker. The flow of reading is more passive where they can be just written directly without placing the main subject in end or between.

The test was revised from a person fluent in English.

 

Author Response File: Author Response.docx

Reviewer 3 Report

In this manuscript, Authors describe the results of a study aimed at investigating the spatial and temporal distribution of non-native macroalgae species in the Venetian Lagoon. The research was conducted in late spring-autumn between 2011 and 2021 at 87 stations. In total, 21 taxa have been recorded, of which the most widespread species was Ulva australis. The authors conclude that the alien species found do not pose a serious threat to the environment, but rather increase biodiversity and may even have a positive impact on ecosystem services.

The manuscript is reasonably well written and presented, however Authors could put more effort into defining a purpose for these studies, as well as providing a proper conclusion.

Specific remarks

Abstract

Line 10                 not ten years, but actually 4 years in ten years, there’s a difference.

Line 17                 I’m not exactly sure what are Authors trying to convey here, is there a sentence missing? Please revise.

Introduction

Line 35                 gross tonnage – I think one, or both of those dots should be a coma.

I think it would be beneficial if authors provide more information about the lagoon, especially its environmental state as its being brought up later in the manuscript.

Material and Methods

Line 72-88           This paragraph would fit more into the Introduction.

Line 96                 Figure 1 caption states 87 stations, please clarify.

Line 97                 I don’t see that information being relevant.

Line 98-100         So there were more than 87 stations? Please clarify.

Line 107-108      I would like to see more information about the molecular part of this study.

I find it disappointing that no hydrological data were recorded, maybe Authors could obtain some relevant satellite data?

Adding some information about the substrate would also be useful.

Unfortunately work also lack in statistics, adding even simple analyses e.g., with hydrological data, would significantly improve the quality of this work.

Results

Results description is kind of lacking in the spatial dimension, maybe Authors could add some more descriptive information, or some graphs?

I would also strongly advise Authors to include some statistical analysis.

Discussion

Line 342-359      Line spacing.

For this type of work, it would be beneficial if Authors could provide some predictions regarding ecological state of the lagoon regarding non-native macrophytes, at which point they could become a threat, etc.

In the abstract Authors state that non-native species are not a thread to the lagoon ecosystem, jet it is not clearly stated in the discussion, please add few sentences as a conclusion.

Kind regards

Reviewer

Author Response

All text additions and changes are shown in red.

 Referee 3

Comments and Suggestions for Authors

In this manuscript, Authors describe the results of a study aimed at investigating the spatial and temporal distribution of non-native macroalgae species in the Venetian Lagoon. The research was conducted in late spring-autumn between 2011 and 2021 at 87 stations. In total, 21 taxa have been recorded, of which the most widespread species was Ulva australis. The authors conclude that the alien species found do not pose a serious threat to the environment, but rather increase biodiversity and may even have a positive impact on ecosystem services.

The manuscript is reasonably well written and presented, however Authors could put more effort into defining a purpose for these studies, as well as providing a proper conclusion.

A conclusion section was added with a discussion of the main results of the paper.

Specific remarks

Abstract

Line 10: not ten years, but actually 4 years in ten years, there’s a difference.

This part was adjusted reporting the 4 years of surveys.

Line 17: I’m not exactly sure what are Authors trying to convey here, is there a sentence missing? Please revise.

The abstract was completely revised.

Introduction

Line 35: gross tonnage – I think one, or both of those dots should be a coma.

Yes, we have changed the points with commas.

 I think it would be beneficial if authors provide more information about the lagoon, especially its environmental state as its being brought up later in the manuscript.

It was done.

Material and Methods

Line 72-88: This paragraph would fit more into the Introduction.

In our opinion the description of the study area in all the papers is reported as a sub-paragraph of “Materials and Methods”.  However, additional information was also inserted in the "Introduction" paragraph.

Line 96: Figure 1 caption states 87 stations, please clarify.

In the map the stations common to the 4 sampling campaigns were only reported. In the text this part has been made clearer.

Line 97: I don’t see that information being relevant.

It was deleted

Line 98-100: So there were more than 87 stations? Please clarify.

This sentence was re-written.

 Line 107-108: I would like to see more information about the molecular part of this study.

The molecular part of this study was reported in all the papers were the NIS or other taxa were identified. However, according to the referee suggestions, we have inserted a new paragraph (2.3. Molecular analyses) with a concise information on this part.

I find it disappointing that no hydrological data were recorded, maybe Authors could obtain some relevant satellite data?

The number of environmental data collected during the 4 campaigns is very high and the subject of other in-depth studies. The purpose of this study is to make an analysis of the alien species present in the soft bottoms of the entire lagoon which present different species in areas with different environmental characteristics. A study of their relationship with environmental characteristics has been done in other papers that analyze single introductions and the idea to insert this analysis in the present paper would be too complex.

 Adding some information about the substrate would also be useful.

As reported above the lagoon present very different soft substrata ranging from very fine to sandy sediment. Some information has been added in the text.

Unfortunately work also lack in statistics, adding even simple analyses e.g., with hydrological data, would significantly improve the quality of this work.

For the same reason no statistical analyses have been added. Indeed, to produce significant results the analysis should be very thorough and detailed and this is not the aim of this study.

Results

Results description is kind of lacking in the spatial dimension, maybe Authors could add some more descriptive information, or some graphs?

In the text we have analysed the distribution and abundance of the single species supplying information on the trophic status, sediment texture and their preferential habitat. More in-deep information is then available in the cited papers.  

I would also strongly advise Authors to include some statistical analysis.

As reported above, due to the relevant amount of data, an analysis of the relationship between macroalgal taxa and environmental parameters is not the aim of this study. In-deep statistical analyses are reported in other papers in preparation where all algal taxa are considered.

Discussion

Line 342-359. Line spacing.

It was adjusted.

For this type of work, it would be beneficial if Authors could provide some predictions regarding ecological state of the lagoon regarding non-native macrophytes, at which point they could become a threat, etc.

It was done

 In the abstract Authors state that non-native species are not a thread to the lagoon ecosystem, jet it is not clearly stated in the discussion, please add few sentences as a conclusion.

We have supplied more information on the non-native species and added a “Conclusion” paragraph with prediction on the ecological status and its evolution.