Dear Authors,

thank you for submitting your responses to the reviewers.

The two available evaluations are very different ("accept as is" and "major revision"); however, all detailed ratings from both reviewers are "good". I therefore decided to go the middle route and suggest minor revision. Reviewer #2 was very engaged and provided an extensive lists of comments. However, you were able to clarify all questions and propose qualitatively well prepared adaptations. I therefore feel comfortable to review the revised manuscript myself (editor review), since the research is also distantly related to mine.

To help me with the review, I would appreciate if you could prepare a revised manuscript with all edits highlighted (track changes).

Let me know in case you have any questions.
All the best
Tina Treude

Dear Martin Schroth and Co-Workers,

thank you for submitting your revised manuscript. The reviewer's suggestions have been implemented well and it is my pleasure to accept your manuscript subject to just one minor technical addition:

In your introduction you write that microbial (meaning biological) methane "is produced by methanogenic archaea (methanogens) under anoxic conditions." We know today that fungi (Eukaryrotes) can produce methane and that some microbes produce methane also under oxic conditions in the surface ocean. I therefore suggest to add this information to your introduction (very briefly). Below are two examples of literature on these topics (but of course feel free to use alternative citations).

All the Best
Tina Treude

Lenhart K, Bunge M, Ratering S, Neu TR, Schüttmann I, Greule M, Kammann C, Schnell S, Müller C, Zorn H, Keppler F. Evidence for methane production by saprotrophic fungi. Nature communications. 2012 Sep 4;3(1):1-8.

Metcalf WW, Griffin BM, Cicchillo RM, Gao J, Janga SC, Cooke HA, Circello BT, Evans BS, Martens-Habbena W, Stahl DA, van der Donk WA. Synthesis of methylphosphonic acid by marine microbes: a source for methane in the aerobic ocean. Science. 2012 Aug 31;337(6098):1104-7.