Methodology and Results of Satellite Monitoring of Karenia Microalgae Blooms, That Caused the Ecological Disaster off Kamchatka Peninsula

Round 1

Reviewer 1 Report

With global climate change and urbanization, the coastal ecosystem suffers serious disturbance, especially for phytoplankton. This paper attempt to develop a spectral shape algorithm for the detection of intensive growth, blooming, and change in the dominant algal species. This is very meaningful and useful. This paper has a strong guiding significance for understanding the occurrence and change of microalgae Karenia spp. bloom. However, the authors need to do much more to improve the paper and make a good scientific story. Kindly, see below for detailed comments:

 1 In the abstract, the methods and advantages of satellite image processing in this study should be introduced in detail. The guiding significance of the study needs to be described in detail.

2 Introduction, the purpose and significance of effective methods for detecting HAB, monitoring, and prediction techniques need further description.

3 Materials and Methods, what is the resolution of the MODIS data of level 0? An analysis of the wind was carried out using data from the WindSat satellite. I haven't seen relevant method and data analysis. It was shown in [40] that the efficiency of phytoplankton photosynthesis is inversely proportional to the fluorescence value. This quotation is not reasonable, just put it after the sentence. Simplify the language and emphasize the selection and calculation of the spectral shape algorithm. 13 samples corresponded to satellite images with a one-day time interval. How does this study apply this data? Whether to take RMSE to evaluate the accuracy of data and remote sensing data?

4 Figure 1, 2, 3, and 4. The east longitude and north latitude should be added. The figure of the geographical location of the research area should be added, including the world location. The basic situation of the research area also needs to be explained. Figures 2, 3, and 4, please add zone 1 and zone 2. Figure 5. Relationship between spectrum shape parameter F488 and biomass of Karenia spp. I don't see any relationship, please provide the relevant data support.

5 Table 2. The data should add SD value and inter-group difference significance.

6 Results. The hotspot area and its ratio change characteristics of Chlorophyll-a concentration should be identified. What is the correlation of research indicators?

7 Please strengthen the effect of upwelling and wind in the discussion, whether the shape of the coastline has an impact on relevant indicators. This will make the paper more meaningful and instructive.

8 Conclusions, please highlight the significance and guiding role of this study.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

I appreciate the opportunity to review the article titled Ecological disaster off Kamchatka Peninsula: Satellite monitor-2 ing of microalgae Karenia spp. bloom. After careful reading, I'd say the article has number of flaws which need to be fixed. Having said that, I have recommendations that I believe the authors will find useful and that, if implemented, would make this research suitable for publication in the journal.

ü  Title –Title of the article is not explicit and somewhat unclear!! I would recommend to authors to revise their title and make it more simple and meaningful.

ü  Abstract – The given abstract requires a slight modification in terms of motivation and implication because it is not acceptable at its current stage. An abstract should begin with a general statement about the topic. Methods and possible results/outcomes are not expressed academically. The study's implication is unclear. At the end of the abstract, kindly include a statement outlining the study's implications having more explicit information regarding the main idea of this article. 

ü  Introduction – The Introduction section should have been improvised, a description of other studies that are related, and most crucially, the research gap that guided the development of this specific research, authors introduced this topic without proper background. I would recommend to establish research idea of the article more explicitly. Without scientific referencing and detailed analysis of those approaches, the conclusion and argument of the article do not sound appropriate. In doing so if required Please rearrange the keywords so that the background of the study sounds appropriate. Having said this, I have the following observations on top of my generic observations mentioned above

(a)   Shorten this chapter and put only relevant informations

(b)  Relevant in text citations are required in many places ( e.g., 144-147 and many other places), try to use recent and relevant citation

(c)   Research objectives should be revised

 

ü  Provide a rationale why the study area has been selected for the study, too much of information need to shorten in the materials and method section and needs to be organized. Provide a presentative study area map with main cartographic element such as index map.

ü  Entire methodology section is poor and vague which make the research unclear in terms of methodological design. It is hard to understand the direction of this research. It is necessary to reorganize the hierarchy of Materials and Methods such, overview of the method, Data Collection, and Data Analysis, validation etc. Please include a brief flowchart to help readers who are unfamiliar with this topic comprehend the study methodology. I do not see any flowchart for this study, please provide a brief but robust flowchart so that reader can be benefited from the study.Writing is not scientifically appropriate in this section. Please shorten this section and only put relevant information.

ü  Figure 2, 3 and 4 are not explicit consider revising them with map scale, unit in the legend etc.  

ü  Need a proper validation process of this work, in the manuscript I do not see any.

ü  Result section is somewhat unclear, authors need to provide an overview what they are going to demonstrate in this section before, provide a brief overview at the beginning of this chapter.

ü  This article does not have a proper discussion section from where the reader can get comparative discussion on data and techniques being utilized for this study and their result and implication for future study, limitation should be included in this study.

ü  Conclusion should be revised, too much of generic sort of discussion here, I cannot see the brief of results of this study here. Please revise conclusion according.

 

please revised plagiarized sentences

 

 

 

 

 

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript presents an explanation of the occurrence of a harmful algal bloom (genus Karenia) which occurred in 2020 and its deleterious consequences on the coastal waters of southern Kamchatka, by using remote sensing images analysis, in situ data regarding algal biomass and meteorological conditions. The manuscript has its merits as it has critically discussed the approach of combining remote sensing with in situ sampling of phytoplankton. The introduction contains all the necessary information but some sections should be rewritten and restructured in order to improve its clarity to the reader. The materials and methods have been adequately described and critically evaluated. The employed methodology and approach are adequate to assess and describe the case study which has been presented.

The discussion has been solidly developed but could be improved by adding other similar studies for comparison and confirmation.

The conclusions should be rewritten to better fit the aim of the manuscript.

The concept of the ecological disaster is important but it is only a possible outcome of the process presented, thus the authors should perhaps focus in the conclusions more on the general issue of bloom monitoring rather than the specific case.

I think that the title of the manuscript could also be modified. As a suggestion: Satellite monitoring of microalgae Karenia spp. bloom that caused the ecological disaster off Kamchatka Peninsula.

As a specific comment in situ should be written in italic.

In the abstract on line 17 the sentence could begin with: In addition, cases of an increase…

Line 18. Instead of writing “The following explanation of events has been offered “, the authors could write: „After analyzing the available data, the events that caused the ecological disaster can be summarized as follows: “

Finally, I think that the graphical presentation of the images should be improved. I would suggest to edit each picture and improve the representation of the coastline, making it bolder or with a higher contrast in order to increase the readability of the images.

Overall, I would recommend the publication after a major revision of the manuscript.

Author Response

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Reviewer 4 Report

The manuscript contains the results of satellite monitoring of a HAB event in Kamchatka in the autumn of 2020. The authors used a variety of techniques to detect the dominant organisms and recognize the stages of algal bloom combining the satellite and ground-based methods. The results obtained show the potential of monitoring in predicting the evolution of HABs and patterns of harmful metabolites distribution.  

There are some points that should be addressed.

The abstract is a bit overloaded and should be reduced to reflect the main contribution of the work to the remote sensing science.

L. 73. a significant number of cells in a sample may contains some species  - please rephrase. Did you mean “may belong to several/different species”?

Materials and methods section: please use past tense throughout the section.

L. 162, Table 1. If there is any data cited from reference 37 in Table 1, please specify it.

 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The revised version meets the requirements of Remote Sensing

Author Response

Thank you for your review

Reviewer 2 Report

I am happy with the revisions. 

Author Response

Thank you for your review

Reviewer 3 Report

The authors improved the overall quality of the manuscript its graphical presentation and have chosen a better title. The English level has been improved. Therefore I would recommend to accept the publication.

Author Response

Thank you for your review