Resilience Approach for Assessing Fish Recovery after Compound Climate Change Effects on Algal Blooms

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors Dear authors, Please find attached your manuscript with my minor suggestions. Best Regards, Reviewer

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

we are very thankful for your comments and suggestions, which helped us to substantially improve the manuscript. You will find below in detail, how we handled each single comment and suggestion. Our responses are given in italics.

Although you list IPCC as a reference in the list of references, please write the full name of the abbreviation.

IPCC is given in full name now.

 

This paragraph (Line 77 – 83 in version 1.0) seems redundant. I suggest moving either part of the paragraph or the whole paragraph to Materials and methods.

Following your suggestion, we moved the description of Oder River from the introduction to the Material and Method section (Line 105 – 111).

 

This bracket is redundant.

The redundant bracket has been deleted.

 

In the tables you refer to the periods before and after August 2022. Please indicate in the text when it is the period before and when it is the period after.

We have added the specific time ranges of the two periods in lines 154-156: “The before August 2022 period was sampled between June 1998 and May 2022. Samples after the catastrophe were taken between end of September 2022 and November 2023.”.

 

Italic.

The species name “Prymnesium parvum” has been formated to italics, throughout the text

Reviewer 2 Report

Comments and Suggestions for Authors

This paper presents the results of an important research giving a way towards prevention of loss of freshwater fish stocks and keep river resilience and should be published.

Authors must consider including (1) species names along the text and (2) add a taxonomic table.

(1)   Adopt the scientific names (instead of common name) along the text. This is specially important to understand which species are more resilient, and which not. Such information may facilitate future collaborative works, as we have an international river.

 

(2)   Add a Taxonomic list of nominal species assigned to the river Oder and the status of those species recognized in the area, if native or introduced species.

 

About the organization of a taxonomic table- Nominal species arranged in alphabetical order (names as originally described containing scientific name plus authorship) followed by columns with the names as in Catalog of fishes- as in Fishbase- as assignment herein (author results) and finally a last column indicating if native/ allien species. This information will give the reader a detailed understanding of the results.

 

This is a signed review. I take this opportunity to congratulate the authors for the ineditity of the study taken. International rivers are in need of research, towards future collaborations without borders.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

we are very thankful for your comments and suggestions, which helped us to substantially improve the manuscript. You will find below in detail, how we handled each single comment and suggestion. Our responses are given in italics.

This paper presents the results of an important research giving a way towards prevention of loss of freshwater fish stocks and keep river resilience and should be published.

Thank you very much for this very positive assessment

 

Authors must consider including (1) species names along the text and (2) add a taxonomic table.

 

(1)   Adopt the scientific names (instead of common name) along the text. This is specially important to understand which species are more resilient, and which not. Such information may facilitate future collaborative works, as we have an international river.

Following your suggestion, we have changed common names to scientific names throughout the text.

 

(2)   Add a Taxonomic list of nominal species assigned to the river Oder and the status of those species recognized in the area, if native or introduced species.

Thank you very much for your suggestion! We have provided a table of all species occurring in our catches as supplementary material (Suppl. Table S1). This checklist of species gives the English and local common names as well information about nativeness as requested. We refer to the supplement in line 188: “The complete checklist of species recorded is provided as supplementary material (Table S1).”.

 

About the organization of a taxonomic table- Nominal species arranged in alphabetical order (names as originally described containing scientific name plus authorship) followed by columns with the names as in Catalog of fishes- as in Fishbase- as assignment herein (author results) and finally a last column indicating if native/ allien species. This information will give the reader a detailed understanding of the results.

See our previous answer. Information is provided as supplementary Table S1. We provided the valid taxonomic names and authorities according to Eschmayers catalog of fishes, but without original names and synonymes, because details of nomenclature are beyond the scope of our study.

 

This is a signed review. I take this opportunity to congratulate the authors for the ineditity of the study taken. International rivers are in need of research, towards future collaborations without borders.

Thank you very much!

 

All these fish species are native from the river basin? Please inform in text.

A sentence stating that all species discussed in this paper are native to the River Oder has been added after the list of fish species in line 176-177.

 

Better use species names, instead of common local name.

Done. See paragraph (1) above

 

Ictalyze species names, as done with the fish taxa.

Done. The species name “Prymnesium parvum” has been formatted to italic

Reviewer 3 Report

Comments and Suggestions for Authors

This study uses a resilience approach to assess the consequences of the River Oder catastrophe for the fish population as well as its recovery potential.The topic is timely and relevant, particularly in the context of climate change and its impact on aquatic ecosystems. The study's methodology is sound, and the results provide valuable insights into the factors influencing fish recovery. However, there are several areas where the manuscript could be improved to enhance its clarity and impact.

Specific Comments:

1. Introduction: The introduction provides a good overview of the context and significance of the study. However, it could benefit from a more detailed explanation of the resilience approach used in the study.

2. Materials and Methods: (1) The description of the study area is clear, but the methods section could be improved by providing more detail on the sampling procedures. For example, it would be helpful to specify the duration of each sampling event and the criteria used for selecting sampling sites. (2) The bootstrapping approach used for data analysis is appropriate, but the rationale for choosing this method should be explained in more detail. Additionally, a brief description of the ggplot2 package and its relevance to the study would be useful for readers unfamiliar with this tool.

3. Results: The results are well-presented, with clear figures and tables. However, some of the tables (e.g., Table 1 and Table 2) are quite dense and could be made more reader-friendly by highlighting key findings or trends.

4. Conclusion: The conclusion provides a good summary of the study's main findings. However, it could be expanded to include a more detailed discussion of the study's implications for future research and practice. For example, the authors could suggest specific areas for further investigation or potential applications of their findings in river management.

Minor Comments:

(1) There are a few typographical errors and inconsistencies in the manuscript that should be corrected. For example, on page 3, line 89, "disentangling" is misspelled as "disentangeling."

(2) The tables should be standardized, and it is recommended to use three-line tables.

Recommendation:

Major Revision: The manuscript presents valuable research but requires significant revisions to improve its clarity and impact. The authors should address the specific comments provided above and consider reorganizing the manuscript to enhance its readability.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Dear Reviewer,

we are very thankful for your comments and suggestions, which helped us to substantially improve the manuscript. You will find below in detail, how we handled each single comment and suggestion. Our responses are given in italics.

This study uses a resilience approach to assess the consequences of the River Oder catastrophe for the fish population as well as its recovery potential.The topic is timely and relevant, particularly in the context of climate change and its impact on aquatic ecosystems. The study's methodology is sound, and the results provide valuable insights into the factors influencing fish recovery. However, there are several areas where the manuscript could be improved to enhance its clarity and impact.

Thank you very much for this assessment!

 

Specific Comments:

1. Introduction:

The introduction provides a good overview of the context and significance of the study. However, it could benefit from a more detailed explanation of the resilience approach used in the study.

More detail on the resilience approach is provided now, in lines 87-90: “Resilience considers the process-based response to environmental fluctuations resulting in natural variation [33]. The two pillars of resilience resistance and recovery are mediated by refuges and dispersal, respectively [34], which are both explicitly considered here.”

 

2. Materials and Methods:

(1) The description of the study area is clear, but the methods section could be improved by providing more detail on the sampling procedures. For example, it would be helpful to specify the duration of each sampling event and the criteria used for selecting sampling sites.

We have added the information on average fishing time for an electrofishing and trawl sample (lines 146-147: “Sampling time for a 400 m stretch is on average 30 minutes but is heavily depending upon fish abundance. The average time spent for a trawl is around 10 minutes”); however, we standardized our fish samplings according to area fished, because it better accounts for spatially explicit differences in fish densities.

 

(2) The bootstrapping approach used for data analysis is appropriate, but the rationale for choosing this method should be explained in more detail. Additionally, a brief description of the ggplot2 package and its relevance to the study would be useful for readers unfamiliar with this tool.

The reasons for using the bootstrapping approach were already explained in the sentence before” “non-normal distributed [data], with high variances and variance heterogeneity between groups.”. For the ggplot2 package we added the source and main application (line 180).

 

3. Results:

The results are well-presented, with clear figures and tables. However, some of the tables (e.g., Table 1 and Table 2) are quite dense and could be made more reader-friendly by highlighting key findings or trends.

Significant changes in percantage changes have ben highlighted in red to enhance the readability.

 

4. Conclusion:

The conclusion provides a good summary of the study's main findings. However, it could be expanded to include a more detailed discussion of the study's implications for future research and practice. For example, the authors could suggest specific areas for further investigation or potential applications of their findings in river management.

Thank you for this suggestion! We have added a paragraph on management implications in lines 406-414: “. From the results two practical management implications can be derived: First, in the short run, efforts need to be increased to further reduce nutrient loads and conductivity, especially during elongated periods of low flow. To achieve this, discharge permits must be changed from regulating loads to discharge to maximum allowable concentrations in the receiving water body. Second, in the middle and long run, the resilience of rivers needs to be enhanced by rehabilitating hydromorphologic processes that generate structural complexity, allow for depth and width variability, island creation and anabranching to create functionally connected refuges and resources.“

 

Minor Comments:

(1) There are a few typographical errors and inconsistencies in the manuscript that should be corrected. For example, on page 3, line 89, "disentangling" is misspelled as "disentangeling."

Thank you for spotting this; has been corrected

 

(2) The tables should be standardized, and it is recommended to use three-line tables.

All tables have been formated with the three-line table format provided by MDPI.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Accept after minor revision

I believe there are more suitable references that need to be cited. Excessive citation of personal literature does not comply with academic norms and the requirements of this journal. It is recommended to replace some of the references Refs.8,10,17,35,36,37,39,40,48,49 and select appropriate references for citation

Author Response

Dear Reviewer 3,

 

you´ll find below in detail, how we handled each single citation. Our response is given in italics.

I believe there are more suitable references that need to be cited. Excessive citation of personal literature does not comply with academic norms and the requirements of this journal. It is recommended to replace some of the references Refs.8,10,17,35,36,37,39,40,48,49 and select appropriate references for citation

 

References 8 (Radinger et al. (2016) and 40 Wolter & Bischoff (2001) have been deleted.  Further, references 36, 37 and 39 have been removed and all replaced by reference 35 as the most comprehensive study on the River Oder fish assemblage before the catastrophe in August 2022. Reference 48 (Wolter et al. (2016) has been replaced by Pearsons et al. (1992) and Marques et al. (2018).

In total, we removed and replaced six out of the ten noted self-citations from the manuscript.

Reference 10 (Markovic et al. (2013) was kept because of being the only example from the region with an evidenced spring warming shift. Reference 17 Parasiewicz et al. (2019) is the only one conceptualizing the response of floods and droughts to climate change that is referred to here. Same with reference 49 (van Treeck et al. 2020), which is the first and only sensitivity classification of European fishes. The remaining reference 35 Wolter et al. (2023) is essential source for the pre- catastrophe data used and analysed here.

With all citations changed, the self-citation rate drops to 8%, which we hope is sufficiently low, because we see no further replacement opportunities without omitting credits to previous work.

 

On behalf of both authors

Sincerely,

Sascha Starck