Influences of Seasonal Variability and Potential Diets on Stable Isotopes and Fatty Acid Compositions in Dominant Zooplankton in the East Sea, Korea

Round 1

Reviewer 1 Report

The manuscript jmse-1992669 entitled “Influences of seasonal variability and potential diets on stable isotopes and fatty acid compositions of dominant zooplankton in the East Sea” explores the effects of seasonal changes in the zooplankton of East Sea.

This is an interesting manuscript. The idea is laid out efficiently and is the organization of the work is commendable.

I have only a few minor suggestions that the authors need to consider.

1.       Delete or replace keyword “zooplankton” – since it is already in the title.

2.       Line 32-33, 40-42 use the following citations to enhance on the point of effects of environmental variabilities on zooplankton. You can also check other sources, as required. <<“Zooplankton community of Bakreswar reservoir: Assessment and visualization of distribution pattern using self-organizing maps”>><<“Environmental factors as indicators of dissolved oxygen concentration and zooplankton abundance: Deep learning versus traditional regression approach>>.

3.       Lines 65-68: trophic network analysis is the only major approach to quantify ecosystem health on a holistic basis. This poinst should be elaborated with proper citations in the manuscript.

4.       Line 68: use the abbreviation “FA” along with the term fatty acid here. Later you can only use the abbreviated form.

5.       Figure 5: update or modify x-axis labels. They are hard to read.

6.       The multi-dimensional scaling shows a great difference at a seemingly minor differentiation between the stress values. The explanation of this observation is not clear from the discussions.

Author Response

Thank you for your comment. I have attached my response in the file below.

Author Response File: Author Response.docx

Reviewer 2 Report

Kim et al. researched the stable isotopes and fatty acid compositions of zooplankton and its relations with phytoplankton biomass in the East Sea. The diet intake of zooplankton can be reduced (restricted) due to the species succession to small-sized phytoplankton and it has important implications for predicting the impact of climate change on micro-ecosystems in the East Sea. The seasonal influences on the zooplankton that cannot convince me due to the only Five samples. The interannual repeats should be included in this manuscript or the authors could think about change the title adequately and revise the manuscript accordingly.

Why the authors collect the samples at the 100m not the surface or any other depth?

Please provide the information “the spatiotemporal dynamics of zooplankton taxa” and discuss it.

Author Response

Thank you for your comment. I have attached my response in the file below.

Author Response File: Author Response.docx

Reviewer 3 Report

This manuscript has an interesting subject dealing with the seasonal variability of potential diets for four major zooplankton groups in the East Sea in response to the fluctuation of primary producers coinciding with the environmental changes. This ms constitutes an interesting piece of work that fits well in the scope of this journal, providing information on the spatio-temporal dynamics of zooplankton feeding and their trophic niches as indicators to characterize the ecological and biochemical processing under current climate change. Overall, the theme is interesting, but there are some small problems in the manuscript for publication.

1) Figure 7: Authors presented the nMDS ordinations of fatty acids and stable isotopes from zooplankton groups. Which data did you use to analyze, especially fatty acids? Full fatty acid profiles? or more than 1% ?  Authors should explain the method in the "Statistical analysis".

2) Why did present the bi-plot of stable isotopes based on the size-fractionated POM and zooplankton groups? This figure may provide better information to understand the trophic niche of zooplankton groups.

3) Title: at the end, add " of Korea" or , ", Korea". 

 

 

 

Author Response

Thank you for your comment. I have attached my response in the file below.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

I don't have any further comments. 

Author Response

Thank you for your review.

We have attached the response as a separate file.
Please check the file.

Thank you

Author Response File: Author Response.docx