Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon Through Microphyte Blooms

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript titled ‘Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon Through Microphyte Blooms’ is written in a very incomprehensible manner by Francesca Polonelli, Marco Leporatti Persiano, Chiara Melillo, and Mauro Lenzi.

Dear Authors,

I am very pleased that the authors have undertaken the task of investigating the issue of dystrophic crises in the Orbetello lagoon by promoting microphyte growth through fundamental research aimed at identifying its causes. However, I regret to inform you that, in its current form, the manuscript is unclear and cannot be considered for publication in the Phycology Journal under any circumstances. In the Abstract, the authors use somewhat obscure terms (18-24) instead of presenting the problem simply and clearly, as is typical for this part of the manuscript. Unfortunately, like the Abstract, the following sections also require much more detailed explanations and will need significant substantive corrections:

• Lines 28-61; This essential introductory section needs to be expanded to accurately describe the issue of macroalgae decomposition and dystrophy, highlighting the release of large quantities of nutrients, especially ammonium nitrogen and orthophosphates, as well as solid particles and dissolved organic matter. This should be explained in detail by including the most relevant diagrams and chemical reactions that clearly illustrate the problem. Only a comprehensive presentation of the previously discussed issues will clearly elucidate the ecological challenges in the Orbetello lagoon and the primary aim of the research described. This information is vital for the manuscript, and it must be explicitly defined – it is an ‘essence without which it cannot exist’ – it is ‘condicio sine qua non’ (!).
• Lines 64-89; Considering all the issues related to the Study Area presented by the authors, it remains unclear whether the samples collected for testing are highly relevant and representative of the entire lagoon (?). The authors did not provide a clear explanation of their methodology, which should also be described in detail, as it is crucial (!).
• Lines 130-136; The Authors noted that the chlorophyll powder obtained was contaminated and required purification before use in their studies. They did not describe the purification method employed nor mention how they verified the purity of chlorophyll after purification (?). After all, the purity of the reagents (materials) used is essential in these studies. The Authors also failed to characterise the properties of the antioxidative agents used in their studies (lines 138-149) in accordance with Pearson’s HSAB concept, nor did they specify their purity. This constitutes a significant oversight (!).
• Lines 90-183, including subsections 2.2–2.6 and unnumbered equations. Due to the climatic, atmospheric, and ecological changes occurring in the Orbetello lagoon, particularly the biological and biochemical changes, the frequency of sampling and the range of variations in the results obtained, along with their associated errors, must be described in detail. The lack of this information means that the results in the following sections are unreliable, and their interpretation is significantly compromised (!).
• Lines 184-329, in Chapter 3, Results, covering subsections 3.1–3.5, Tables 1–3, and Figures 2–10, present their results in a highly incorrect manner, i.e., without a detailed description of the errors, as I already mentioned in my opinion on the previous chapter. A significant omission in this chapter is the lack of descriptions for the photographs presented as Figures and Tables, which are ‘places to put very puzzling data’. Everything is also poorly done, and the authors have not bothered to present the chart titles in English - see Figure 6, page 13 (!).
• Lines 330-450, i.e., Chapter 4, Discussion, contains virtually no interpretation of the results obtained (although I have already pointed out that they are incorrect (!)), which is required in this chapter. This chapter gives the impression that it is thematically related to other studies. This is another glaring error in this manuscript.
• The authors’ omission of this essential requirement is a serious error (!). I deeply regret that the authors have not demonstrated a creative approach in their research aims. While authors are not expected to present their Figures solely as photos produced through giclée printing (fine art printing), it is understood that even lower-quality images must maintain a high level of clarity.
• The subsection 5. Conclusions contain overly general information; therefore, their content requires substantial revision. Dear Authors, please improve the clarity of all the subsections in the final version of this manuscript (!). The state of the peer-reviewed article is depressing. Without any offence to the authors, however, they are in the wrong aisle (!). Therefore, the authors should withdraw their manuscript from the Editorial Board of the Phycology Journal (?).

 

Comments on the Quality of English Language

Dear Authors, please revise your manuscript to conform to standard British English.

 

Author Response

• The manuscript titled ‘Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon Through Microphyte Blooms’ is written in a very incomprehensible manner by Francesca Polonelli, Marco Leporatti Persiano, Chiara Melillo, and Mauro Lenzi.

  Dear Authors,

  I am very pleased that the authors have undertaken the task of investigating the issue of dystrophic crises in the Orbetello lagoon by promoting microphyte growth through fundamental research aimed at identifying its causes. However, I regret to inform you that, in its current form, the manuscript is unclear and cannot be considered for publication in the Phycology Journal under any circumstances. In the Abstract, the authors use somewhat obscure terms (18-24) instead of presenting the problem simply and clearly, as is typical for this part of the manuscript. Unfortunately, like the Abstract, the following sections also require much more detailed explanations and will need significant substantive corrections:

  • Lines 28-61; This essential introductory section needs to be expanded to accurately describe the issue of macroalgae decomposition and dystrophy, highlighting the release of large quantities of nutrients, especially ammonium nitrogen and orthophosphates, as well as solid particles and dissolved organic matter. This should be explained in detail by including the most relevant diagrams and chemical reactions that clearly illustrate the problem. Only a comprehensive presentation of the previously discussed issues will clearly elucidate the ecological challenges in the Orbetello lagoon and the primary aim of the research described. This information is vital for the manuscript, and it must be explicitly defined – it is an ‘essence without which it cannot exist’ – it is ‘condicio sine qua non’ (!).
  • "condicio sine qua non" or "conditio sine qua non", the matter is a bit tricky.

   What Reviewer 1 asks for is well-known and established. The paper is not didactic, but technical and aimed at colleagues in the field. It seemed essentially superfluous to go into detail (relevant diagrams and chemical reactions!), However, accepting the criticism, we further developed the Introduction, which probably seemed sparse and essential, even though the citations reported referred to other works that addressed what Reviewer 1 requested.

   

  • Lines 64-89; Considering all the issues related to the Study Area presented by the authors, it remains unclear whether the samples collected for testing are highly relevant and representative of the entire lagoon (?). The authors did not provide a clear explanation of their methodology, which should also be described in detail, as it is crucial (!).

  We have clarified the methodology for macroalgae and LOM in M&M. Microphyte sampling was not done to determine how microphytes were distributed throughout the lagoon, but to examine the microphytic components of the blooms that determined the intense coloration of the waters, which flowed from west to east during the dystrophic phase.

   

  • Lines 130-136; The Authors noted that the chlorophyll powder obtained was contaminated and required purification before use in their studies. They did not describe the purification method employed nor mention how they verified the purity of chlorophyll after purification (?). After all, the purity of the reagents (materials) used is essential in these studies. The Authors also failed to characterise the properties of the antioxidative agents used in their studies (lines 138-149) in accordance with Pearson’s HSAB concept, nor did they specify their purity. This constitutes a significant oversight (!).

  we ask to the Referee to explain what means: in the lines indicated we did not mention chlorophyll powder obtaining or purification methods, but above all, we had not included any data in this paper concerning chlorophyll. Furthermore, we used  neutralized formaldehyde 37% (adding sodium tetraborate until pH 7 was reached) to preserve the samples. We add this in the text.

   

  • Lines 90-183, including subsections 2.2–2.6 and unnumbered equations. Due to the climatic, atmospheric, and ecological changes occurring in the Orbetello lagoon, particularly the biological and biochemical changes, the frequency of sampling and the range of variations in the results obtained, along with their associated errors, must be described in detail. The lack of this information means that the results in the following sections are unreliable, and their interpretation is significantly compromised (!).

  For subsection 2.2, the equations have been numbered. The biomass estimation method is well-established and standardized with a significant number of samples for macroalgae, where it was useful for establishing the average density of the mats. The same applies to the sampling in subsection 2.3. These methods have been proposed in numerous other international publications and have never been contested; however, we have attempted to describe them more accurately. In subsection 2.4, the records are hourly and provide a very specific temperature trend. Salinity, however, exhibits much less frequent variations, so periodic field measurements were used. For space reasons, we have only provided the range of pH values. Subsection 2.5 has undergone further revision.

   

  • Lines 184-329, in Chapter 3, Results, covering subsections 3.1–3.5, Tables 1–3, and Figures 2–10, present their results in a highly incorrect manner, i.e., without a detailed description of the errors, as I already mentioned in my opinion on the previous chapter. A significant omission in this chapter is the lack of descriptions for the photographs presented as Figures and Tables, which are ‘places to put very puzzling data’. Everything is also poorly done, and the authors have not bothered to present the chart titles in English - see Figure 6, page 13 (!).

  The chapter has been extensively revised and corrected for inconsistencies and careless errors.

   

  • Lines 330-450, i.e., Chapter 4, Discussion, contains virtually no interpretation of the results obtained (although I have already pointed out that they are incorrect (!)), which is required in this chapter. This chapter gives the impression that it is thematically related to other studies. This is another glaring error in this manuscript.

  The chapter has been extensively revised

   

  • The authors’ omission of this essential requirement is a serious error (!). I deeply regret that the authors have not demonstrated a creative approach in their research aims. While authors are not expected to present their Figures solely as photos produced through giclée printing (fine art printing), it is understood that even lower-quality images must maintain a high level of clarity.

  We have tried to improve the images as much as possible

   

  • The subsection 5. Conclusions contain overly general information; therefore, their content requires substantial revision. Dear Authors, please improve the clarity of all the subsections in the final version of this manuscript (!). The state of the peer-reviewed article is depressing. Without any offence to the authors, however, they are in the wrong aisle (!). Therefore, the authors should withdraw their manuscript from the Editorial Board of the Phycology Journal (?).

  A review has been done

   

  Dear Authors, please revise your manuscript to conform to standard British English.

  The manuscript is in British English

   

Reviewer 2 Report

Comments and Suggestions for Authors

Review for the paper “Evolution of a dystrophic crisis in a non-tidal lagoon through microphyte blooms” by Francesca Polonelli, Marco Leporatti-Persiano, Chiara Melillo, Mauro Lenzi submitted to “Phycology”.

 

The authors of this research paper conducted an analysis of a severe dystrophic event that transpired in the Orbetello lagoon, Italy, during the summer of 2024. They tired to attribute this event to a series of environmental factors. The study monitored pre-existing conditions of macroalgal masses and labile organic matter as well as variations in temperature and dissolved oxygen levels in the lagoon waters, both preceding and during the dystrophic event. The authors also cataloged the microphyte taxa and the relative abundance of dominant classes that significantly influenced the evolution of the dystrophic process. Satellite imagery were used to document the dynamics of the event over time. The results suggest that the dystrophy was driven by a combination of factors: an accumulation of LOM and the degradation of macroalgal masses, exacerbated by a notable increase in temperatures and inadequate water circulation.

The implications of this study could be profound, particularly in terms of understanding the dynamics of aquatic ecosystems under climate change.

 

However, some additional statistical analyses are required to more rigorously support the authors' conclusions

 

Recommendations.

 

Introduction.

 

L 31. The authors should clarify the types of human activities contributing to this nutrient increase.

 

L 37-38. The authors mentioned a trophic shift from angiosperms to opportunistic species and eventually to microphyte dominance in extreme conditions. They should clarify what time frame these trophic shifts generally follow.

 

L 54. The authors noted that Cyanobacteria blooms often occur during advanced macroalgal decay and dystrophic events. They should clarify whether these blooms result in additional negative environmental effects, such as toxin production or further oxygen depletion.

 

Materials and Methods.

 

L 70-72. The authors should mention the relative contributions of these sources (land-based fish-farm wastewater, agricultural runoff, and urban wastewater) to overall nutrient loading. It would be useful to specify which nutrient types (nitrogen, phosphorus) are most dominant from each source.

 

L 93-94. The authors should explain how frequently macroalgal biomass was collected during the study period. Were temporal variations accounted for? How representative the sampling points are for the basin as a whole?

 

L 100-101. What is the spatial resolution for satellite images? Did the authors validate the macroalgal extent derived from satellite imagery against field observations?

 

L 128. The authors' use of dissolved oxygen and pH data from June–September 2024 to analyze environmental conditions requires clarification. The authors should explain why these months were chosen. Is the data representative of annual or long-term lagoon conditions?

 

Results.

 

Section 3.2. It would be useful to statistically compare data between the two basins (Figures 4 and 5) and between different months (Table 2).

 

L 244. Change "Table 3" to "Table 2".

 

L 245-249. The authors should format the references according to the recommended style, using numbers in square brackets.

 

Section 3.3. It would be useful to statistically compare data between the two basins (Figure 6 and 5) and between different months (Table 2).

 

L 282. The authors stated, "The list is compared with lists of microphytic developments observed in the past." However, this statement is unclear in light of the following text. Did the authors intend to say that these lists were comparable?  If so, they should perform a relevant statistical analysis, such as PERMANOVA, based on abundance or presence/absence data, to confirm this statement.

 

Figure 9. The authors should explain the meaning of the values reported under each column (e.g., 63.30, 9.32…).

 

Discussion.

 

L 420-421. The authors clarify which specific genera or species were likely responsible for the initial pink coloration of waters and if any direct microbiological observations or measurements were conducted to confirm this.

 

L 449. The authors referenced forced water changeovers ending in mid-September as potentially influencing bloom dynamics. They should clarify what “forced water changeovers” entailed (mechanical pumping or natural inflows).

 

The authors should discuss the results presented in Section 3.5.

Comments on the Quality of English Language

Minor revisions are required.

Author Response

Review for the paper “Evolution of a dystrophic crisis in a non-tidal lagoon through microphyte blooms” by Francesca Polonelli, Marco Leporatti-Persiano, Chiara Melillo, Mauro Lenzi submitted to “Phycology”.

The authors of this research paper conducted an analysis of a severe dystrophic event that transpired in the Orbetello lagoon, Italy, during the summer of 2024. They tired to attribute this event to a series of environmental factors. The study monitored pre-existing conditions of macroalgal masses and labile organic matter as well as variations in temperature and dissolved oxygen levels in the lagoon waters, both preceding and during the dystrophic event. The authors also cataloged the microphyte taxa and the relative abundance of dominant classes that significantly influenced the evolution of the dystrophic process. Satellite imagery were used to document the dynamics of the event over time. The results suggest that the dystrophy was driven by a combination of factors: an accumulation of LOM and the degradation of macroalgal masses, exacerbated by a notable increase in temperatures and inadequate water circulation.

The implications of this study could be profound, particularly in terms of understanding the dynamics of aquatic ecosystems under climate change.

However, some additional statistical analyses are required to more rigorously support the authors' conclusions

 

Recommendations.

 

Introduction.

L 31. The authors should clarify the types of human activities contributing to this nutrient increase.

Done and inserted in M&M study area

 

L 37-38. The authors mentioned a trophic shift from angiosperms to opportunistic species and eventually to microphyte dominance in extreme conditions. They should clarify what time frame these trophic shifts generally follow.

What is reported in the Introduction in this regard concerns a general aspect of the changes in submerged populations that occur following eutrophication, as reported by Duarte (1995). This shift is also mentioned for the Orbetello lagoon and this aspect is reported in the citation Lenzi et al. (2012).

 

L 54. The authors noted that Cyanobacteria blooms often occur during advanced macroalgal decay and dystrophic events. They should clarify whether these blooms result in additional negative environmental effects, such as toxin production or further oxygen depletion.

Done

 

Materials and Methods.

L 70-72. The authors should mention the relative contributions of these sources (land-based fish-farm wastewater, agricultural runoff, and urban wastewater) to overall nutrient loading. It would be useful to specify which nutrient types (nitrogen, phosphorus) are most dominant from each source.

Done

 

L 93-94. The authors should explain how frequently macroalgal biomass was collected during the study period. Were temporal variations accounted for? How representative the sampling points are for the basin as a whole?

We clarified that sampling was conducted during the period of greatest growth and extension of the mats, i.e. May-June (excluding February 2024). The number of samples taken for mat density varied according to their extent. The field operation was intended to establish only the density of the mats, while their extent was estimated remotely. It is clear that the method may have margins of uncertainty, but it has been applied over time using the same procedures, so we believe that the results are comparable.

 

L 100-101. What is the spatial resolution for satellite images? Did the authors validate the macroalgal extent derived from satellite imagery against field observations?

Done

 

L 128. The authors' use of dissolved oxygen and pH data from June–September 2024 to analyze environmental conditions requires clarification. The authors should explain why these months were chosen. Is the data representative of annual or long-term lagoon conditions?

Dystrophies occur at temperatures above 25-26°C and, as we explain in the text, normally at temperatures well above those, but in any case in relation to poor hydrodynamics and high LOM. This phenomenon therefore normally occurs between June and August. We have therefore taken a sufficiently long period, between June and September. It would have been pointless, for the purposes of this study, to consider periods with significantly lower temperatures, as these periods have no influence whatsoever on the onset of the phenomenon. We clarify this in the text.

 

Results.

 

Section 3.2. It would be useful to statistically compare data between the two basins (Figures 4 and 5) and between different months (Table 2).

In reality, the trends are not very different, but even if we established that DO or T were significantly different in the two basins, this would not prove anything, because dystrophic conditions occurred in both basins. Furthermore, the variables at play are not only DO and T, but numerous others, including the distribution of macroalgal masses, including species, some of which are easily perishable, others resistant to stress. Furthermore, temperatures reached relatively high values in both basins, even in relation to the period 2013-2024.

 

L 244. Change "Table 3" to "Table 2".

Done

 

L 245-249. The authors should format the references according to the recommended style, using numbers in square brackets.

Done

 

Section 3.3. It would be useful to statistically compare data between the two basins (Figure 6 and 5) and between different months (Table 2).

The variance is high and there are no significant differences between the two basins, but what was said in paragraph 3.2 also applies to paragraph 3.3.

 

L 282. The authors stated, "The list is compared with lists of microphytic developments observed in the past." However, this statement is unclear in light of the following text. Did the authors intend to say that these lists were comparable?  If so, they should perform a relevant statistical analysis, such as PERMANOVA, based on abundance or presence/absence data, to confirm this statement.

No, no comparison is made between the lists. We simply report what has been found in other papers at different times. We have clarified that the 1996 list comes from a study carried out during a very critical phase, while the 2003 list, on the contrary, is the result of a study conducted during a non-critical phase of the lagoon basin. This is reflected in the number of species.

 

Figure 9. The authors should explain the meaning of the values reported under each column (e.g., 63.30, 9.32…).

we corrected

 

Discussion.

 

L 420-421. The authors clarify which specific genera or species were likely responsible for the initial pink coloration of waters and if any direct microbiological observations or measurements were conducted to confirm this.

We identified, to the best of our knowledge and laboratory availability, only microalgal species and not bacterial species, so, as we say in the text, the pink colouring could be due to purple sulphur-oxidising bacteria. In those initial samples, Bacillariophyceae were abundant, which should have given them a brown colour. However, this microalgal population did not affect the DO, so either it was unable to counteract the anoxic conditions - and therefore it is likely that aerobic sulphur-oxidising bacteria were present - or they were highly stressed organisms, no longer able to photosynthesise, previously attached to the benthos and brought into suspension by the dystrophic event. We discuss this in the text.

 

 

L 449. The authors referenced forced water changeovers ending in mid-September as potentially influencing bloom dynamics. They should clarify what “forced water changeovers” entailed (mechanical pumping or natural inflows).

This is described in M&M, which mentions the pumping of sea water between April and September from two pumping stations in the West Basin, to the outlet of the lagoon waters into the sea, via the sea-lagoon canal in the East Basin.

 

The authors should discuss the results presented in Section 3.5.

We have attributed the ability to counteract dystrophic criticalities to the microphyte developments of photosynthetic organisms. The evolution of these populations can, more or less quickly, depending on the characteristics of the population, resolve these criticalities. Furthermore, we report the composition of these populations in relation to DO concentration.

 

Comments on the Quality of English Language

Minor revisions are required.

 

 

Reviewer 3 Report

Comments and Suggestions for Authors

The authors talked about Microphyte Bloom Dynamics Shaping the Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon. Below are my concerns/comments:

1. Extend the monitoring period before and after the dystrophic event to better capture long-term environmental shifts and ecosystem recovery dynamics.
2. Characterize anaerobic bacterial and broader microbial communities during different dystrophy phases to understand their contribution to oxygen depletion and organic matter degradation.
3. Identify critical thresholds (e.g., dissolved oxygen <X mg/L, temperature >Y °C, LOM levels) that could be used to develop an early-warning system for future dystrophic events.
4. Compare the 2024 dystrophy with previous events to highlight similarities and differences in drivers (e.g., climatic anomalies, hydrodynamics, algal composition).
5. Suggest practical management interventions, such as controlled macroalgal biomass removal, artificial aeration, or restoration of hydrodynamics (e.g., water exchange with the sea), to reduce recurrence risk.
6. Discuss how projected warming trends and extreme temperature events may increase the frequency and intensity of dystrophic processes in Mediterranean lagoons.

Author Response

The authors talked about Microphyte Bloom Dynamics Shaping the Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon. Below are my concerns/comments:

1 - Extend the monitoring period before and after the dystrophic event to better capture long-term environmental shifts and ecosystem recovery dynamics.

These phenomena are not easily predictable, so monitoring was triggered at a certain point, missing some moments. However, we had available temperature and dissolved oxygen values, LOM, and macroalgal mass.

 

2 - Characterize anaerobic bacterial and broader microbial communities during different dystrophy phases to understand their contribution to oxygen depletion and organic matter degradation.

This is no longer possible. Unfortunately, the study was not planned, as the phenomenon was not anticipated, so we attempted to collect data while it was occurring

 

3 - Identify critical thresholds (e.g., dissolved oxygen <X mg/L, temperature >Y °C, LOM levels) that could be used to develop an early-warning system for future dystrophic events.

a protocol for this purpose exists and has been included in the text, although the event remains difficult to predict. We mentioned it in the Introduction.

 

4 - Compare the 2024 dystrophy with previous events to highlight similarities and differences in drivers (e.g., climatic anomalies, hydrodynamics, algal composition).

This would be desirable, unfortunately we do not have enough information to make a comparison, furthermore, it must be said, the variables are many and I can say that each time a dystrophy has a different history and shows different effects. A specific mathematical model would be needed

 

5 - Suggest practical management interventions, such as controlled macroalgal biomass removal, artificial aeration, or restoration of hydrodynamics (e.g., water exchange with the sea), to reduce recurrence risk.

This is not the objective of the paper. In other studies, environmental management solutions to prevent dystrophies and to manage emerging critical conditions (pre-dystrophic state) have been proposed.

 

6 - Discuss how projected warming trends and extreme temperature events may increase the frequency and intensity of dystrophic processes in Mediterranean lagoons.

Done

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript titled ‘Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon Through Microphyte Blooms’ is still incomprehensibly written by Francesca Polonelli, Marco Leporatti Persiano, Chiara Melillo, and Mauro Lenzi.

Dear Authors,

As I noted in my review of the previous version of this manuscript, I am very honoured that the Authors have undertaken to investigate dystrophic crises in the Orbetello lagoon by promoting microphyte growth through foundational research aimed at identifying their causes. This effort was, and remains, highly significant, but it must be articulated with great precision; therefore, the current version of the manuscript still requires some clarification. The Abstract subsection is now edited consistently and unambiguously, thereby communicating effectively. The Authors also write the Introduction subsection clearly and effectively. However, the final part (lines 224–229) should be slightly expanded to provide unambiguous information for the subsequent subsections.

 Nevertheless, the following sections also demand more detailed explanations and will require significant substantive corrections:

• Lines 332-344: The equations VI–VIII(?) are crucial for this section of the manuscript, and therefore, the Authors must precisely describe the application of these equations! Additionally, the last of these equations should be labelled as VIII.
• Lines 420-422: Was the activity of anaerobic bacteria at high summer temperatures controlled in any way in the lagoon?
• Lines 629-692: A very detailed commentary on Table 1 is necessary, for example, explaining what caused the approximately 40% decline in the standing crops (SC) in 2022. The Authors entirely overlook this very puzzling result (?).
• Lines 909(?)-915: There is an apparent discontinuity in line numbering, and Figures 5-6 need to be properly described (!). This information is vital for the manuscript, and it must be explicitly defined — it is an ‘essence without which it cannot exist’ — it is ‘condiciosine qua non’ (!).
• Lines 1061-1077: Both Table 3, which is essential for this manuscript, and Figures 8 A-F, which are equally necessary, must be discussed in detail. It is also ‘condiciosine qua non’ (!).
•  
• Lines 184-329, in Chapter 3, Results, covering subsections 3.1—5, Tables 1—3, and Figures 2–10, present their results in a highly incorrect manner, i.e., without a detailed description of the errors, as I already mentioned in my opinion on the previous chapter. A significant omission in this chapter is the lack of descriptions for the photographs presented as Figures and Tables, which are ‘places to put very puzzling data’. Everything is also poorly done, and the authors have not bothered to present the chart titles in English — see Figure 6, page 13 (!).
• Only a comprehensive presentation of the previously discussed issues will clearly elucidate the ecological challenges in the Orbetello lagoon and the primary aim of the research described. This information is vital for the manuscript, and it must be explicitly defined — it is an ‘essence without which it cannot exist’ — it is ‘condicio sine qua non’ (!).
• The subsection Conclusions currently includes valuable additions and relevant summaries based on the previous subsections. Dear Authors, please revise the manuscript in accordance with the recommendations to produce the final version. The reviewed article is not discouraging, but it still requires essential corrections (!).

 

Comments on the Quality of English Language

Dear Authors, please revise your manuscript to conform to standard British English.

Author Response

The manuscript titled ‘Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon Through Microphyte Blooms’ is still incomprehensibly written by Francesca Polonelli, Marco Leporatti Persiano, Chiara Melillo, and Mauro Lenzi.

Dear Authors,

As I noted in my review of the previous version of this manuscript, I am very honoured that the Authors have undertaken to investigate dystrophic crises in the Orbetello lagoon by promoting microphyte growth through foundational research aimed at identifying their causes. This effort was, and remains, highly significant, but it must be articulated with great precision; therefore, the current version of the manuscript still requires some clarification. The Abstract subsection is now edited consistently and unambiguously, thereby communicating effectively. The Authors also write the Introduction subsection clearly and effectively. However, the final part (lines 224–229) should be slightly expanded to provide unambiguous information for the subsequent subsections.

 

The lines reported do not correspond to those in the manuscript, both those in question and in the subsequent references

 Nevertheless, the following sections also demand more detailed explanations and will require significant substantive corrections:

• Lines 332-344: The equations VI–VIII(?) are crucial for this section of the manuscript, and therefore, the Authors must precisely describe the application of these equations!

These aspects, although very important, are beyond the scope of our study. Furthermore, they are well-known phenomena found in the cited literature.

• Additionally, the last of these equations should be labelled as VIII.

Done

 

• Lines 420-422: Was the activity of anaerobic bacteria at high summer temperatures controlled in any way in the lagoon?

No specific study on bacterial populations has been carried out

 

• Lines 629-692: A very detailed commentary on Table 1 is necessary, for example, explaining what caused the approximately 40% decline in the standing crops (SC) in 2022. The Authors entirely overlook this very puzzling result (?).

The decay in macroalgal biomass is essentially due to summer conditions; this is explained in the text. Although all the aspects discussed in the manuscript are worthy of further exploration, explaining in detail the causes of macroalgal mats decay in a given year, taking into account the numerous variables, would require excessive text size, and furthermore, it is not required by the objectives of the manuscript.

 

• Lines 909(?)-915: There is an apparent discontinuity in line numbering, and Figures 5-6 need to be properly described (!). This information is vital for the manuscript, and it must be explicitly defined — it is an ‘essence without which it cannot exist’ — it is ‘condicio sine qua non’ (!).

             In Discussion, we examined the trends of DO and T during June-September 2024, for T emphasizing the high values ​​reached and their duration, for DO emphasizing the duration of the anoxic phase and the "strange" coincidence with anoxia and high densities of Bacillariophyceae, for which we hypothesized that either this microalgal development was unable to counteract the dystrophic phenomenon, or these organisms were previously benthic, epiphytic on the macrovegetation and carried in suspension by the gas flow, under strong stress.

• Lines 1061-1077: Both Table 3, which is essential for this manuscript, and Figures 8 A-F, which are equally necessary, must be discussed in detail. It is also ‘condiciosine qua non’ (!).

For Table 3, we do not have the information to provide a thorough comparison between the reported microphyte lists, except for the difference between a non-critical and dystrophic environmental condition, which we mentioned earlier.

We have added discussion points to section 4.2, including the environmental conditions of the 2003 list, and specie comparison between the dystrophic periods 1986-89 and 2024. However, we felt it was important to provide the available microphyte lists as information for any future comparisons. The fluctuations of these populations are unclear and the variables at play are many, so the lists, when accurate, become a valuable resource.

Regarding Figure 8, we described the process from the formation of white water due to the development of hydrogen sulfide to the development of intense pink/red-brown colors. Initially, we could only hypothesize the development of SOB, and subsequently attribute the color to the various microalgae.

 

• Lines 184-329, in Chapter 3, Results, covering subsections 3.1—5, Tables 1—3, and Figures 2–10, present their results in a highly incorrect manner, i.e., without a detailed description of the errors, as I already mentioned in my opinion on the previous chapter. A significant omission in this chapter is the lack of descriptions for the photographs presented as Figures and Tables, which are ‘places to put very puzzling data’. Everything is also poorly done, and the authors have not bothered to present the chart titles in English — see Figure 6, page 13 (!).

We don't understand which errors the reviewer is referring to.

In Figure 6, temperature trend, the title was present. In Figure 5, DO trend, the title is missing, but the caption is clear. We believed a title is not a necessary condition when the caption is sufficiently clear.

We have enriched the captions of Figures 8, 10, 11 and 12.

 

• Only a comprehensive presentation of the previously discussed issues will clearly elucidate the ecological challenges in the Orbetello lagoon and the primary aim of the research described. This information is vital for the manuscript, and it must be explicitly defined — it is an ‘essence without which it cannot exist’ — it is ‘condicio sine qua non’ (!).

We understand the reviewer's concerns, but we would like him to also consider the objectives of the manuscript, which are not so ambitious as to clarify the ecological challenges of the Orbetello lagoon, a complex and chaotic system where predictions are difficult due to chronic hypertrophy. The objective was simply to link photosynthetic microphyte developments with dystrophies, which can evolve more or less rapidly precisely as a result of those developments. This study, with its limitations, is a first step in evaluating the coupling of these two phenomena, with the ultimate goal of being able, in the future, to manage microalgal developments to mitigate their critical issues

 

• The subsection Conclusions currently includes valuable additions and relevant summaries based on the previous subsections. Dear Authors, please revise the manuscript in accordance with the recommendations to produce the final version. The reviewed article is not discouraging, but it still requires essential corrections (!).

We thank the Reviewer for his patience in carefully reviewing the manuscript and allowing us to improve the previous, excessively hasty exposition and expand the description of the problem.

Reviewer 2 Report

Comments and Suggestions for Authors

No further comments.

Author Response

We thank the Reviewer for his patience in carefully reviewing the manuscript and allowing us to improve the previous, excessively hasty exposition and expand the description of the problem

Reviewer 3 Report

Comments and Suggestions for Authors

The authors had replied to the questions/concerns. The paper can be accepted in its present form.

Author Response

We thank the reviewer for their contribution.

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript titled ‘Evolution of a Dystrophic Crisis in a Non-Tidal Lagoon Through Microphyte Blooms’ is quite clearly written by Francesca Polonelli, Marco Leporatti Persiano, Chiara Melillo, and Mauro Lenzi.

Dear Authors,

Having analysed the current version of this manuscript, it has been written in accordance with the general standards for experimental scientific articles and, once approved by the Editorial Board, should be forwarded to the subsequent stages of the publication process.

Comments on the Quality of English Language

Dear Authors, I still ask you to correct the manuscript to comply with standard British English — it is an ‘essence without which it cannot exist’ — it is ‘condicio sine qua non’ (!).

 

Author Response

We have converted all text to British English. In addition, we have made minor changes to some captions. We thank the reviewer for the contribution.