The Influence of Arctic Conditions on the Formation of Algae and Cyanobacteria Diversity and on the Water Quality of Freshwater Habitats on Kotelny Island, Lena Delta Wildlife Reserve, Yakutia

Round 1

Reviewer 1 Report

The manuscript is devoted to the study of the species composition of algae and cyanobacteria in 12 small, diverse water bodies of Kotelny Island. The authors identified indicator species and analyzed their spatial distribution, conducted an ecological-geographical analysis, and also identified environmental factors influencing the diversity of algae on Kotelny Island. The water bodies are located beyond the Arctic Circle in the zone of continuous occurrence of permafrost soils and is characterized by harsh climatic conditions. Research in the area is currently ongoing due to the potential for industrial development of the coastal territory and shelf. The study of the ecology and species diversity of algae in the Arctic is of particular importance in connection with the phenomena of global climate change. The results of the study are important for developing the basis for monitoring biodiversity under the conditions of anthropogenic and climatic changes in the Arctic.

Overall, the manuscript looks good, undoubtedly relevant for the field and presented in a well-structured manner. The cited references are mostly recent publications. Self-citation is 12%. The manuscript is scientifically based. The Materials and Methods section is clearly presented. The data is understandable, easy to interpret, and appropriate and consistent throughout the manuscript. Statistical analysis was carried out using correct methods. The conclusions are consistent with the evidence and arguments presented.

However, there are some small comments and questions:

 Line 145-154. Figure 3 completely repeats Table 2.

 Line 160-162. Table 3. What does the last "Sum" column mean? Maybe I don't understand. What is added up? Is the number of taxa below the genus of dominant taxa at the genus level in each habitat indicated? Are all the species within the genus not repeated in different bodies of water?

Line 206. I do not see information about Index S in table 4.

Class of Water Quality - no link. Please explain what the classes correspond to.

Line 262. In the caption "Index Saprobity S" and in the figure "Water Quality".

It was somewhat surprising that the use of groups of indicators of trophic status in the water bodies of the island. Kotelny showed that mesotrophic species predominate, in contrast to oligotrophic assessments of the waters of neighboring regions.

Author Response

Dear Editor,

Thank you and the Reviewer 1 for comments. Please consider the responses to each comment below.

With best regards,

Prof Sophia Barinova,

Corresponding author

Reviewer 1 Report 1

The manuscript is devoted to the study of the species composition of algae and cyanobacteria in 12 small, diverse water bodies of Kotelny Island. The authors identified indicator species and analyzed their spatial distribution, conducted an ecological-geographical analysis, and also identified environmental factors influencing the diversity of algae on Kotelny Island. The water bodies are located beyond the Arctic Circle in the zone of continuous occurrence of permafrost soils and is characterized by harsh climatic conditions. Research in the area is currently ongoing due to the potential for industrial development of the coastal territory and shelf. The study of the ecology and species diversity of algae in the Arctic is of particular importance in connection with the phenomena of global climate change. The results of the study are important for developing the basis for monitoring biodiversity under the conditions of anthropogenic and climatic changes in the Arctic.

Overall, the manuscript looks good, undoubtedly relevant for the field and presented in a well-structured manner. The cited references are mostly recent publications. Self-citation is 12%. The manuscript is scientifically based. The Materials and Methods section is clearly presented. The data is understandable, easy to interpret, and appropriate and consistent throughout the manuscript. Statistical analysis was carried out using correct methods. The conclusions are consistent with the evidence and arguments presented.

However, there are some small comments and questions:

 Line 145-154. Figure 3 completely repeats Table 2.

Response: corrected

 Line 160-162. Table 3. What does the last "Sum" column mean? Maybe I don't understand. What is added up? Is the number of taxa below the genus of dominant taxa at the genus level in each habitat indicated? Are all the species within the genus not repeated in different bodies of water?

Response: corrected.

Line 206. I do not see information about Index S in table 4.

Response: added Ref 47

Class of Water Quality - no link. Please explain what the classes correspond to.

Response: added Ref 47

Line 262. In the caption "Index Saprobity S" and in the figure "Water Quality".

Response: corrected

It was somewhat surprising that the use of groups of indicators of trophic status in the water bodies of the island. Kotelny showed that mesotrophic species predominate, in contrast to oligotrophic assessments of the waters of neighboring regions.

Author Response File: Author Response.pdf

Reviewer 2 Report

Title: The influence of Arctic conditions on the formation of algae diversity and water quality on the Kotelny Island, Lena Delta Wildlife Reserve, Yakutia

 General comments

The authors have studied freshwater ‘algae’ and Cyanobacteria in twelve sites of the Arctic island of Kotelny (Yakutia). More than 210 taxa are reported. The authors deserve admiration for sampling under such harsh conditions. Although the analysis is only qualitative (which is regrettable), it will provide a valuable baseline in the context of climate change.

English language is often very difficult to understand, sometimes really incomprehensible, especially in the introduction. Sorry if some of my comments are due to a misunderstanding of the text. The text should be proofread by a native English speaker.

The authors should clarify that 'algae' is taken in its customary sense. Algae do not constitute a taxon, but a highly polyphyletic group; the authors should make this clear and cite a reference, e.g. (but other references can be chosen as well):

Boudouresque C.F., Caumette P., Bertrand J.C., Normand P., Sime-Ngando T., 2015. Systematic and evolution of microorganisms: general concepts. In: Environmental microbiology: Fundamentals and applications. Microbial ecology. Bertrand J.C., Caumette P., Lebaron P., Matheron R., Normand P., Sime-Ngando T. (eds.), Springer publ.: 107-144.

Boudouresque C.F., 2015. Taxonomy and phylogeny of unicellular eukaryotes. In: Environmental microbiology: Fundamentals and applications. Microbial ecology. Bertrand J.C., Caumette P., Lebaron P., Matheron R., Normand P., Sime-Ngando T. (eds.), Springer publ.: 191-257.

The authors sometimes include bacteria (as cyanobacteria or Cyanophyceae) within ‘algae’, which should be avoided. The title mentions only ‘algae’, while the text usually deals with algae AND cyanobacteria.

Ulvophyceae are absent. Authors should clarify whether they were excluded from sampling. Otherwise, they should emphasize their absence from the freshwater habitats studied.

The authors list not only species, but varieties and non-identified taxa (see e.g. Oedogonium sp., Spirogyra sp. ster., table A1). They should therefore replace 'species' with ‘taxa'. everywhere.

Only freshwater habitats were studied. This should be mentioned in the title and in the abstract.

The authors should specify the sampling effort per station. Obviously, a 1-min sampling time probably provide less taxa than e.g. a 6-hour sampling time.

The analysis is only qualitative (presence or absence of taxa). It is understandable that sampling allowing quantitative analysis, under such harsh conditions, would have been very time-consuming, if not even impossible. But it is clear that this greatly limits the scope of the discussion and conclusions. Additionally, qualitative data is more sensitive to sampling effort than quantitative data. When comparing with other islands and with the work of other authors, the sampling effort of the latter is unfortunately unknown, while this could account for observed differences.

The discussion seems confused; it is mixing data taking in account, or not, plankton, benthos and fossils. The comparisons therefore seem of poor interest. The discussion should be rewritten and greatly shortened.

Other remarks

Lines 20 and 414. Zygnematophycen? zygnematophycean.

Line 37. I cannot understand the meaning of ‘the stability of ecosystems at the border of survival’

Line 40. What is the meaning of CAFF?

Line 64. Protist is a customary term deprived of taxonomic value. Please delete.

Lines 103-105. What is the sampling effort per station? Obviously, a 1-min sampling time could provide less taxa than e.g. a 6-hour sampling time.

Lines 113-115. Figure 1. Please add a metric scale (Kotelny Island). Latitude and longitude are not enough.

Lines 116-118. Please indicate the number and name of the photographed waterbodies.

Line 123. The legend for table 1 is missing.

Table 1. Sampling dates: day/month/year would be better than month/day/year. 4x5 m is not a surface area but a length (i.e. 20 m): you should repeat the unit (4 m x 5 m). Station 8: altitude 38 m (short description) or 53 m (elevation)?

Table 2. Cyanophyceae (vs. cyanobacteria in the text): please standardize. What is the meaning of a-a, b, Ha and k? Although defined elsewhere, should also be defined in the legend of Table 2.

Figure 3. Cyanophyceae? Or Cyanobacteria. Why is station 8 omitted?

Figure 6. What is the meaning of a-a, b, Ha and k? Although defined elsewhere, should also be defined in the legend of Figure 6.

Table A1. Please indicate that '0' means 'absent' and '1' means 'present'.

Author Response

Dear Editor,

Thank you and the Reviewer 2 for comments. Please consider the responses to each comment below.

With best regards,

Prof Sophia Barinova,

Corresponding author

Responses to the Reviewer 2 Report 1

Comments and Suggestions for Authors

Title: The influence of Arctic conditions on the formation of algae diversity and water quality on the Kotelny Island, Lena Delta Wildlife Reserve, Yakutia

General comments

The authors have studied freshwater ‘algae’ and Cyanobacteria in twelve sites of the Arctic island of Kotelny (Yakutia). More than 210 taxa are reported. The authors deserve admiration for sampling under such harsh conditions. Although the analysis is only qualitative (which is regrettable), it will provide a valuable baseline in the context of climate change.

English language is often very difficult to understand, sometimes really incomprehensible, especially in the introduction. Sorry if some of my comments are due to a misunderstanding of the text. The text should be proofread by a native English speaker.

RESPONSE: thank you for your comments, text was accordingly corrected

The authors should clarify that 'algae' is taken in its customary sense. Algae do not constitute a taxon, but a highly polyphyletic group; the authors should make this clear and cite a reference, e.g. (but other references can be chosen as well):

Boudouresque C.F., Caumette P., Bertrand J.C., Normand P., Sime-Ngando T., 2015. Systematic and evolution of microorganisms: general concepts. In: Environmental microbiology: Fundamentals and applications. Microbial ecology. Bertrand J.C., Caumette P., Lebaron P., Matheron R., Normand P., Sime-Ngando T. (eds.), Springer publ.: 107-144.

Boudouresque C.F., 2015. Taxonomy and phylogeny of unicellular eukaryotes. In: Environmental microbiology: Fundamentals and applications. Microbial ecology. Bertrand J.C., Caumette P., Lebaron P., Matheron R., Normand P., Sime-Ngando T. (eds.), Springer publ.: 191-257.

RESPONSE: corrected on the lines 211-213. Added two references

The authors sometimes include bacteria (as cyanobacteria or Cyanophyceae) within ‘algae’, which should be avoided. The title mentions only ‘algae’, while the text usually deals with algae AND cyanobacteria.

RESPONSE: corrected

Ulvophyceae are absent. Authors should clarify whether they were excluded from sampling. Otherwise, they should emphasize their absence from the freshwater habitats studied.

RESPONSE: inserted on the lines 284-285

The authors list not only species, but varieties and non-identified taxa (see e.g. Oedogonium sp., Spirogyra sp. ster., table A1). They should therefore replace 'species' with ‘taxa'. everywhere.

RESPONSE: changed as taxa over the text and figures 3 and 6.

Only freshwater habitats were studied. This should be mentioned in the title and in the abstract.

RESPONSE: done

The authors should specify the sampling effort per station. Obviously, a 1-min sampling time probably provide less taxa than e.g. a 6-hour sampling time.

RESPONSE: Sorry, we did not find the relevant content to comment

The analysis is only qualitative (presence or absence of taxa). It is understandable that sampling allowing quantitative analysis, under such harsh conditions, would have been very time-consuming, if not even impossible. But it is clear that this greatly limits the scope of the discussion and conclusions. Additionally, qualitative data is more sensitive to sampling effort than quantitative data. When comparing with other islands and with the work of other authors, the sampling effort of the latter is unfortunately unknown, while this could account for observed differences.

The discussion seems confused; it is mixing data taking in account, or not, plankton, benthos and fossils. The comparisons therefore seem of poor interest. The discussion should be rewritten and greatly shortened.

RESPONSE: Thank you for your comments, we try to follow all of them and hope that all questions were answered.

Other remarks

Lines 20 and 414. Zygnematophycen? zygnematophycean.

RESPONSE: thank you for comment, corrected

Line 37. I cannot understand the meaning of ‘the stability of ecosystems at the border of survival’

RESPONSE: This is Odum's term when environmental factors push the existence of an ecosystem to the brink of existence. That is, the survival of a community, an ecosystem in critical environmental factors, on the border of changing conditions of existence.

Line 40. What is the meaning of CAFF?

RESPONSE: added Добавил пояснение на строках 40-41

Line 64. Protist is a customary term deprived of taxonomic value. Please delete.

RESPONSE: the term was changed

Lines 103-105. What is the sampling effort per station? Obviously, a 1-min sampling time could provide less taxa than e.g. a 6-hour sampling time.

RESPONSE: Sorry, we did not find the relevant content to comment

Lines 113-115. Figure 1. Please add a metric scale (Kotelny Island). Latitude and longitude are not enough.

RESPONSE: done

Lines 116-118. Please indicate the number and name of the photographed waterbodies.

RESPONSE: done

Line 123. The legend for table 1 is missing.

RESPONSE: Thank you, corrected.

Table 1. Sampling dates: day/month/year would be better than month/day/year. 4x5 m is not a surface area but a length (i.e. 20 m): you should repeat the unit (4 m x 5 m). Station 8: altitude 38 m (short description) or 53 m (elevation)?

RESPONSE: corrected. Thank you for comment.

Table 2. Cyanophyceae (vs. cyanobacteria in the text): please standardize. What is the meaning of a-a, b, Ha and k? Although defined elsewhere, should also be defined in the legend of Table 2.

RESPONSE: done

Figure 3. Cyanophyceae? Or Cyanobacteria. Why is station 8 omitted?

RESPONSE: The figure lists the classes. Class Cyanophyceae, Phylum Cyanobacteria. There's no mistake here. Figure 3 replaced.

Figure 6. What is the meaning of a-a, b, Ha and k? Although defined elsewhere, should also be defined in the legend of Figure 6.

RESPONSE: done

Table A1. Please indicate that '0' means 'absent' and '1' means 'present'.

RESPONSE: Added Note under Table A1 with explanation

Author Response File: Author Response.pdf

Reviewer 3 Report

Review of "The influence of Arctic conditions on the formation of algae diversity and water quality on the Kotelny Island, Lena Delta Wildlife Reserve, Yakutia"

Overall Impression:

This manuscript presents an interesting study on the diversity and water quality of aquatic habitats on Kotelny Island, a protected area in the Russian Arctic. The authors have identified 210 species of algae and cyanobacteria, conducted bioindicator analysis, and investigated the influence of environmental factors on the formation of these communities. The manuscript is well-written and organized, with clear methods and results. The authors have collected a large dataset of species diversity and environmental variables, which allows for a detailed analysis of the studied ecosystems. The use of bioindicators provides valuable insights into the ecological status of the water bodies and the potential impacts of environmental factors. The authors have employed appropriate statistical methods to analyze their data, including network correlation analysis and Pearson similarity calculations. The manuscript is well-written and organized, with clear figures and tables that effectively present the results. While there a few comment that will improve the MS as fellows:

·        While the authors mention the influence of environmental factors, they could provide a more detailed discussion of how these factors specifically affect the observed patterns of diversity and water quality. Check these paper: https://doi.org/10.1016/j.ecolind.2024.111721

·        The authors could suggest future research directions, such as investigating the long-term effects of climate change on the aquatic ecosystems of Kotelny Island.

·        The authors could consider using a more consistent format for the species names throughout the manuscript.

·        The authors could consider adding a glossary of terms for readers who are not familiar with the ecological terminology used in the manuscript.

·        Choose one format (either "St.1" or "1") and use it consistently throughout the manuscript. Make sure that all figures, tables, and references also use the same format.

·        I would like to suggest that you avoid using personal pronouns such as "we" and "our" throughout the manuscript.

·        I also recommended using palmer index for organic pollution indicators. https://doi.org/10.1007/s00477-020-01809-w

Overall, this is a well-written and informative manuscript that provides valuable insights into the diversity and water quality of aquatic habitats on Kotelny Island. The authors could strengthen their manuscript by addressing the weaknesses and suggestions for improvement outlined above.

Comments for author File: Comments.pdf

Author Response

Dear Editor,

Thank you and the Reviewer 3 for comments. Please consider the responses to each comment below.

With best regards,

Prof Sophia Barinova,

Corresponding author

Responses to the Reviewer 3 Report 1

Review of "The influence of Arctic conditions on the formation of algae diversity and water quality on the Kotelny Island, Lena Delta Wildlife Reserve, Yakutia"

Overall Impression:

This manuscript presents an interesting study on the diversity and water quality of aquatic habitats on Kotelny Island, a protected area in the Russian Arctic. The authors have identified 210 species of algae and cyanobacteria, conducted bioindicator analysis, and investigated the influence of environmental factors on the formation of these communities. The manuscript is well-written and organized, with clear methods and results. The authors have collected a large dataset of species diversity and environmental variables, which allows for a detailed analysis of the studied ecosystems. The use of bioindicators provides valuable insights into the ecological status of the water bodies and the potential impacts of environmental factors. The authors have employed appropriate statistical methods to analyze their data, including network correlation analysis and Pearson similarity calculations. The manuscript is well-written and organized, with clear figures and tables that effectively present the results. While there a few comment that will improve the MS as fellows:

• While the authors mention the influence of environmental factors, they could provide a more detailed discussion of how these factors specifically affect the observed patterns of diversity and water quality. Check these paper: https://doi.org/10.1016/j.ecolind.2024.111721

RESPONSE: Sorry, we didn't find any suitable content for this comment. We familiarized ourselves with it but did not find an opportunity to somehow mention it in our work, and the regions are completely different. And they discuss other environmental parameters - there is hydrochemistry, which we do not have.

• The authors could suggest future research directions, such as investigating the long-term effects of climate change on the aquatic ecosystems of Kotelny Island.

RESPONSE: the relevant fragment added in lines 800-804

• The authors could consider using a more consistent format for the species names throughout the manuscript.

RESPONSE: It is not clear what "more uniform format for species names" means, species are listed according to the cited resource - a modern taxonomic database of algae, cited as [44].

• The authors could consider adding a glossary of terms for readers who are not familiar with the ecological terminology used in the manuscript.

RESPONSE: A description of each group of indicators is given in the footer of Table 4 and Appendix Table A2 and reference [47]

• Choose one format (either "St.1" or "1") and use it consistently throughout the manuscript. Make sure that all figures, tables, and references also use the same format.

RESPONSE: done. Unified "St.1" in Tables

• I would like to suggest that you avoid using personal pronouns such as "we" and "our" throughout the manuscript.

RESPONSE: done across the text

• I also recommended using palmer index for organic pollution indicators. https://doi.org/10.1007/s00477-020-01809-w

RESPONSE: Unfortunately, we cannot calculate the Palmer index, since we do not have the abundance of each species in the communities and, especially, cannot compare with chemical indicators, which were not determined due to the inaccessibility of the study area and, therefore, limited sampling or instrumentation capabilities. Our hope was to establish environmental indicators using bioindicators, which was carried out in a detailed analysis.

Overall, this is a well-written and informative manuscript that provides valuable insights into the diversity and water quality of aquatic habitats on Kotelny Island. The authors could strengthen their manuscript by addressing the weaknesses and suggestions for improvement outlined above.

Author Response File: Author Response.pdf

Reviewer 4 Report

It is an interesting topic. The bioindication method used for the first time on Kotelny Island. Some suggestions:

Line 12, what kind of environmental risks?

Line 19, under what conditions were the samples collected in 2018 stored and when were they analysed? What was the temperature in August?

Line 56, where were 148 species discovered?

Line 88, please write the environmental factors affecting the diversity of photosynthetic microorganisms.

Although the results found were presented well, the lack of discussion with similar studies conducted in different locations was found inadequate.

For Table 4 note, lines 98-101, lines 119-122, similarities should be checked again using iThenticate report

Author Response

Dear Editor,

Thank you and the Reviewer 4 for comments. Please consider the responses to each comment below.

With best regards,

Prof Sophia Barinova,

Corresponding author

Responses to the Reviewer 4 Report 1

Comments and Suggestions for Authors

It is an interesting topic. The bioindication method used for the first time on Kotelny Island. Some suggestions:

Line 12, what kind of environmental risks?

RESPONSE: Risks associated with the development of oil fields on the Arctic shelf

Line 19, under what conditions were the samples collected in 2018 stored and when were they analysed? What was the temperature in August?

RESPONSE: in subsection ‘2.2 Sampling and laboratory study’ it is noted that fixed material was studied. This made it possible to save algological samples and process them later in the laboratory. During sampling, the temperature was positive, above zero Celsius.

Line 56, where were 148 species discovered?

RESPONSE: These 148 species were discovered in the water bodies of the Faddeevsky Peninsula as a result of the work of L. A. Ushnitskaya et al. Cited in text as [4]: [Ushnitskaya, L.A.; Gorodnichev, R. M.; Spiridonova, I. M.; Pestryakova, L. A. Preliminary limnological characteristics of water bodies of the Faddeevsky Peninsula (New Siberian Islands). International Journal of Applied and Fundamental Research 2013, 8(2), pp. 189–192.]

Line 88, please write the environmental factors affecting the diversity of photosynthetic microorganisms.

RESPONSE: In the Conclusion, we noted that cold northeastern winds have the greatest influence on aquatic communities of microorganisms.

Although the results found were presented well, the lack of discussion with similar studies conducted in different locations was found inadequate.

RESPONSE: A detailed comparison was made with previously published research results from various authors in the region of this Arctic archipelago. However, comparison with studies in other regions, such as tropical or even temperate ones, would not be adequate, since the Arctic flora is not only different from others, but is also very individual even on the Arctic coast, which is cited. However, perhaps the authors did not understand what “different locations” means.

For Table 4 note, lines 98-101, lines 119-122, similarities should be checked again using iThenticate report

RESPONSE: Sorry, we did not find content for correction because Table 4 is in lines 198-215. So lines 98-101 is site description about weather, and lines 119-122 is about the method for diatom shells cleaning.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Fo not forget to delete the words and sentences that have been replaced by a new word or sentence!