Dear Johanna and Volker,

both reviewers are supportive of your study, but have raised several issues that require a major revision to improve the overall quality of the manuscript. Two major points both reviewer's highlighted are that the manuscript needs a more consistent organization (more clarity) and that some detailed information (both in methods and discussion) is missing. I am confident, based on your replies, that you will be able to accomplish both of the requests.

As for the request to provide a numerical model for your interpretations I leave the decision up to you depending on the applicability. I understand that given the simultaneous occurrence of different processes within the same sediment layers, a model appears difficult. It might at least be worth mentioning this complication in the discussion as it provides helpful guidance for future studies.

In cases where you disagree with the reviewers please consider at least if it is worth clarifying these aspects in the manuscript as some of these points raised by the reviewers might have just resulted from insufficient or misleading presentation.

After your submission of the revised manuscript, the manuscript will be sent back to the reviewers.

With kind regards
Tina Treude
BG Editor

Dear Dr. Sawicka, Dear Volker,

your manuscript was sent back to the most critical referee # 2 and returned with major revisions, because some of the aspects that you proposed to correct ultimately did not make it into the revised manuscript.

Please have a close look at the comments and follow the requests and advice of the referee where you can do so. Please make a step-by-step response to all requests and submit a revised manuscript with all edits highlighted.

In case the revision is satisfactory and easy to follow, there might be no need to send the manuscript back to the referee. I am confident that even though major revision has been requested you should be able to accomplish the requests relatively easily.

Best wishes
Tina Treude
BG Editor

Dear Johanna and Volker,

thank you for submitting your revised manuscript. I consider it now suitable for publications. I have just a few technical corrections, which you can easily accomplish. Please see below. The line numbers refer to the line numbers in the manuscript with tracked changes.

Merry X-Mas and a Happy New Year!
Tina Treude

Technical Corrections:

533: Please enter name of research vessel ("on-board" which vessel?)

633: Please provide a one sentence introduction of the purpose of this incubation at the beginning of the paragraph.

643 and 653: I suggest to make these sub-capters of 2.7, because they belong to the incubation (2.7.1 and 2.7.2)

654: Methane fluxes of what? Benthic fluxes? Please add information.

654: Was the water sample taken close to the sediment interface or in the bulk supernatant water. Please clarify.

679: Chapter must than be 2.8 (see above)

735: Please comment that the detection limit of the IC is 100 µM for sulfate (see your comment in the answers to the reviewer)

744: Rates integrated over which depth?

865: "comparable" should better read "similar"

908: "Sediment focusing" sounds a bit strange. Rewording?

933: Sentence has 2 x "to greater depth". Maybe re-wording?