Dear Martijn Hermans and Co-Authors,

thank you for submitting your responses to the reviewers to Biogeosciences. As you probably noticed, one of the referees suggested minor, while the other one suggested major revisions.

I decided to go with minor revisions (i.e., editor review), because the main criticism that lead to the suggestion of major revisions was the presentation style and I am confident from your responses that you will take good care of clarifying issues such as the comparability between artificial experiment and natural (Black Sea) environment in your revision.

A few additional comments from my side:

- Instead of 'bottom water' you could also use the term "supernatant" or 'bottom-near" water. I was in the past criticized by physical oceanographers for using the term 'bottom water' in my sediment studies, because it is a fixed term in oceanography and covers a large volume (an entire water mass).

- The term "suboxic" opposite to oxic and anoxic is not ideal, because suboxic is also anoxic. But I am aware that the term is frequently used together with cable bacteria biogeochemistry. I am OK with keeping the term, but please double check that your final manuscript has a proper definition of the terms at the beginning (oxic = with O2, suboxic = anoxic but not sulfidic, anoxic = anoxic and sulfidic).

- In Fig. 2B a red and a green profile are shown in the same graphs. Please use a different color to allow green-red handicapped people to enjoy it.

Let me know in case you have any questions.
Looking forward to receive your revised manuscript.
Best
Tina Treude

Dear Martijin and Co-workers,
thank you for submitting your revised manuscript to Biogeosciences. Requests from reviewers have been implemented satisfactory. It is my pleasure to accept your manuscript.
With kind regards
Tina Treude