Community Structure and Abiotic Characteristics of Pelagic Microalgal in Adjacent Areas of the Barents Sea and Kara Sea

Round 1

Reviewer 1 Report

Three major issue：

1. I cannot find the results of pigments concentration which the authors introduced in the methods.

2. The discussion should be improved to match the points metioned in the introudution section.

3. The quality of figures should be impoved.

The other comments are in the attached PDF file.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 1,

We thank you for your valuable suggestions and comments. We are deeply grateful for your time spent on our manuscript. All of your comments and correction we accepted and tried to enhance our manuscript as best as we could. The main changes are in figures, in abstract, materials and methods, and discussion. Also we added detailed data in appendix. The language corrections also applied all over the paper to improve the perception of the material.

We hope that, with changes made, the paper is more suitable for publication.

Author Response File: Author Response.docx

Reviewer 2 Report

Overall this paper has some interesting data to discuss, but the manuscript is not ready for publication in its current condition. Abundance and biomass figures should be created that relate to the actual species found, rather than just where in the water column they were found. The authors must have this breakdown available because differences of the sort are discussed within lines 344-348 and throughout the coinciding paragraph. Grammar and clarity should be improved throughout. Another figure should be added that show the currents described in the Discussion section. The figures deserve a bit more attention to detail (specifics are in the text below). A bit of restructuring may be in order, as portions of the results section seemed that they belonged within the discussion section. Some of the interpretations of results are unclear. Citing figures that support the claims made more often could help clarify those points. Not all claims in the results, discussion, and conclusion felt comfortably substantiated. The second to last paragraph in the conclusion seems to contradict itself in saying how there was low variability between results over long-term collections yet phytoplankton conservation is essential.

 

Numbers below refer to specific lines:

27: Marine phytoplankton “are” a base... or another change, the grammar seems off with this first line.

Grammar could be improved throughout the first few paragraphs.

62: Seems the most promising for what?

64: Example of “such seawater areas”? What do you mean by this?

65-66: can you describe what is relevant in the citation here, and what do you mean be assumption.

68: What do you mean “great importance” here? Why? Please substantiate the claim with evidence.

Figure 1: please include a scale bar.

104: please list the target depths for water collection.

112: Are there any citations that you could include for AlgaeBase and WORMS here?

106: Can you indicate why such a large range in volumes? Same with line 116.

In the methods, were there any steps not mentioned here? For example, was acetone added to chlorophyll-a samples before measurements were made? Other statements such as “according to standard methodology” in line 110 was also vague. A careful eye to include more detail would be encouraged for the methods section.

124: Add a citation for the Winkler method please.

131-133: Seems like you forgot to take this text out of a previous draft?

Figures 2 and 3 should include a map figure of how these transects were drawn for a quick reference. The axis text is also a bit distorted. If you are comparing these sites, I would keep the color bar along the same scale. Also, where did the bathymetry file used come from? What is it?

148: The results talk about station 21 but station 21 does not actually appear in Figures 2 or 3.

Figure 4: All of these plots were made from water collected at one station? The plots are overreaching with the interpolation used. That’s a big generalization for 4 degrees of latitude with bathymetric variability. If you have these measurements collected from more than one station, then they should be interpolated starting from the actual depths they were measured at from each station.

 

165: What is the “upper active seawater layer”?

Figure 5: Maybe change the color of the dots used based on the station locations for give more information here.

Figure 6: why do some plots have contour lines and labels while others do not? Why is this figure different from Figure 5 in design, though the caption is identical save for the location of the sample site.

Lines 204-206: Please cite something that supports that claim.

Figure 7: I would like to know which depths count as surface layer and how far from the seafloor is “near bottom layer” used here.

Figure 8 – for comparison of these two sites, it would be helpful if the color bars had the same scale. This was a good feature of your Fig 7. The axis labels are again distorted.

Figure 9: the color scale used here is nonintuitive and perhaps even confusing. Text is distorted.

221-223: Please add another line on what the direct correlation is that you mentioned. Or perhaps there is a more in-depth discussion on it within your Discussion section. If not, please address.

Line 227: This high value is not obvious – it looks like station 7 has the highest value within the trough. Maybe indicate what the turbidity value of station 6 actually was, and why you would expect to see it at the shallowest point (because it is not so obvious to the reader).

 

Table 1- so the white background indicates the species was found in both areas? Please say that explicitly in the caption.

 

Reference table 1 earlier when discussing the types within each study area.

 

Line 258: unsure of what you mean by “registered were organisms...”

Line 261: cosmopolitans made up the largest share of the algal communities found but these were absent in SEBS? Please make this point clearer.

Line 272 and on seem like they could belong in the discussion section as well. Figures 10 and 11 should be referenced earlier within the discussion of abundance and biomass (e.g lines 276 and 289). What may actually be more appropriate would be another type of figure that shows the abundance and biomass of the actual species found.

Lines 301-304 are unclear. Please reword.

Line 309 – how was the range of variation measured? Hos was significance determined?

Line 324: Instead of using language such as “The first region” please keep it straightforward by using the location names. “Scatter of values” is also unclear language. Maybe more distributed throughout the water column? Not sure what you are trying to say here.

Line 327: Are you sure there is no noticeable differences between stations and seas? SEBS appears to consistently have more abundance at depth relative to what’s in the water compared to SWKS to me. Or are you determining vertical structure of algal communities by a different metric? Please be clear.

Line 332: remove “quite”

Lines353-360- please include  some illustration of the described figures.

Line 367- Not sure what “It shows” is referring to. Past literature that are uncited in this line? Your results?

Lines 384-387- this is a bit confusing. Maybe helpful to break up this sentence.

Lines 395-400-this sentence is also a bit long, and there should be some studies cited that use the technique explained within.

Line 402- what is the mixed-synthesis phase?

The last line (402-405) contains an argument that I’m not sure I see the full reasoning for. Perhaps more of an elaboration on mixed-phase and the specifics of studies within the paragraph could help support this claim.

I would leave out the word “obvious” throughout, it does not strengthen the connections described and alienates some readers. (e.g. line 411)

Line 415- unclear what is meant by “closeness.” Similarity in physical location, or in the hydrological characteristics? Here would be a good opportunity to more explicitly tie this back into the themes discussed in the introduction.

The paragraph that falls within lines 416-431 feels like it makes a lot of assumed conclusions drawn on the abundance and biomass values obtained by the data, but the link between the conclusions on phenology stage and species found is not very clear. I think more specifics are necessary here between the taxa that are found in the spring bloom based on previous work, but were not found in your data, and maybe why that might be would be helpful.

Line 447- another example of where to remove “its” to instead just say what it is.

Line 453- change “encreased” to “increased”

Line 455 – remove “out”

Line 462-464- this claim about sea ice not having an impact seems unfair without a description of ice conditions for the years of data that the authors results are being compared to.

 

 

Author Response

Dear Reviewer 2,

The authors are deeply grateful for the time spent on our manuscript. We thank you for your valuable suggestions and comments. All of your comments and correction we accepted and tried to enhance our manuscript as best as we could. The main changes are in figures, in abstract, materials and methods, and discussion. Also we added detailed data in appendix. The language corrections also applied all over the paper to improve the perception of the material. As for cartography issues: we used GEBCO base layer for bathymetry (Figure 1); scale bar is not very useful in case of Mercator projection, we have added scale value to the map. All other questions indicated by you, we tried to disclose in the text of the article.

We hope that, with changes made, the paper is more suitable for publication.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Thank you for your thorough response to the previous concerns. The manuscript has improved since the original copy. Most importantly, I think the inclusion of the Appendix is hugely helpful. Below I list some remaining concerns. I think after adequately addressing what’s below, the paper can be proof-read and published.

 

 

In the abstract, both “south-western” and “southeastern” are used. I would remove the “-“  from “south-western” in line 11.

Line 14: Remove extra space between the track changes text and “during a…”

Line 37: Citation [4] is in its own sentence, beginning and ending with a period.

Line 42: is the text supposed to read as “water masses”?

Line 46: Please replace “task at hand” with what you specifically mean.

Figs 2,3 and others with bathymetry: I see from the author response they’ve used GEBCO bathymetry, I think it would be beneficial to mention that within the figure caption (at least the first time it’s used, if not for all transect figures).

Lines 150-152: I’m a little confused on the observation of near-bottom water of station 21 being cited here as the maximum value of salinity when stations 25 and 26 seem more saline throughout? And wouldn’t weak influence of Atlantic water mean it would be fresher water? Maybe some clarification within the text would help relieve my confusion on this.

Figure 5: the text including the axis labels and the R^2 value are very difficult to read; please make these larger.

Lines 169-171: are these averages for all the areas combined? In lines 186-188 you discuss these averages for SEBS separately, so please make this clearer within the text.

Figure 6: It’s great that the colors are unified so stations can be compared, but in instances where you have contours on a solid color as is the case in figure 6 c (for example) there is no information to be gleaned here by a reader. To alleviate this, I suggest labeling the values of the contour lines within the figures.

Line 200: why is this 0.45 mg/m^3 limit important here? Is that the maximum that was reached? If so, please reword this to say this was the maximum, or why else that threshold was significant.

Line 387: missing a period after the citation.

Line 394: Spell check on “differe”

Lines 393-396 are supported by the references in [54, 55] in line 392? I would cite something to support within.

Line 421 and on stating “The analysis performed gives reasons to assert that the pelagic algal communities in the seawater regions under comparison, despite these differences, were at the same stage of the seasonal succession…” can you specifically describe the evidence on how you can determine they were at the same stage of succession?

Line 428 stating “All the parameters of algal communities corresponded to the summer and autumn phases of the annual growing cycle” deserves a reference that would describe summer and autumn communities expected there. It seems contradictory to the paragraph starting at line 397 which states this knowledge is a gap. Specific examples of community compositions for the comments at 428 would be helpful.

Author Response

Dear reviewer!

Here is an edited version of our manuscript. We thank you for your comments and attention to our manuscript.  All the reviewers’ comments and recommendations are carefully considered and accepted as far we understood them.

Thank you for your consideration!

Author Response File: Author Response.docx