Dear Daffne C. López-Sandoval,
Thank you for submitting your manuscript “Rates and drivers of Red Sea plankton community metabolism” to Biogeosciences.
After considering the reviewers’ comments and your detailed answers, I believe your manuscript may be suitable for publication after major revisions.
In fact, both the reviewers recognized the high relevance of the scientific question you addressed and the value of the dataset you presented. At the same time, they had significant concerns on the methods and their presentation, including the quality of the text. I appreciated that you believe there was a misunderstanding about the processes you measured and presented in the manuscript, as you are going to clarify in your revision.
The revised version should take into account all the feedbacks provided in the referees’ assessment and it should include all the changes that you agreed in your answers to the reviewers. For your information, I will send your revision for a second round of reviews.
I look forward to receiving your revised manuscript.
Sincerely,
Stefano Ciavatta

Dear Daffne C. Lopez-Sandoval,
Your revised manuscript was re-assessed by the second reviewer and by me. You responded satisfactorily to all the issues that were raised in the first round of reviews. You improved the description of the methods and results, enhancing the clarity of your work and its impact on our knowledge on the functioning of the Red Sea ecosystem.
I am kindly asking you to please address the few comments of mines below. Afterwards, I will finalize my decision on the publication of your manuscript.
Thank you in advance,
Kind regards
Stefano

My suggested changes to the text:
1) Please make clear in the abstract and elsewhere that your results can not be extended to warm oligotrophic tropical regions. In fact, the warmest part of the Red Sea is also the less oligotrophic, to my understanding.
It seemed to me that you suggested your study could be useful to investigate warmer, more oligotrophic oceans in the framework of climate changes (line 11). But this is not the case, as you recognized at line 19-20.
2) At line 24, please replace “demonstrate” with “suggest”, as you wrote at line 361.
3) The activation energies of GPP and CR are reported with positive values at times (e.g. line 17), with negative values at other times (e.g. lines 293-294). Please use signs coherently throughout the text.
4) Please be consistent in rounding the correlation coefficient values in Table 1. E.g., the correlation between NOx and CR and NCP is 0.19 at line 206-207, and 0.1 in Table 1. On the other hand, the correlation of chlorophyll and GPP is 0.69 at line 200, but 0.7 in Table 1.
5) Please do not overestimate the relevance of correlation coefficients and of their statistical significance to identify links or even causality between environmental factors (see e.g. https://www.tandfonline.com/doi/full/10.1080/00031305.2019.1583913).
In this regards, is it possible that the correlations between GPP, CR and NCP with NOx were less significant than the ones with temperature because of a lower number of NOx data? Please specify in the text how many data of each variable you have measured and included in the statistical analysis.

Dear Daffne C. López-Sandoval,

Thank you for addressing my comments positively. I am pleased to accept your manuscript, "Rates and drivers of Red Sea plankton community metabolism”, for publication in Biogeosciences.

Sincerely,
Stefano Ciavatta
Associate Editor