Dear Dr. Schmidt:

Thank you for submitting your paper to Biogeosciences. I have read your paper, the reviews and your rebuttal and believe that a revised would make a nice contribution to the field. I therefore invite you to submit a revision incorporating the feedback and along the lines of your rebuttal.

With best regards, Jack Middelburg, Associate Editor

Dear Dr.Schmidt:

Thank you for submitting this nice paper to Biogeosciences. I enjoyed reading and very much appreciated the comprehensive approach. I am therefore happy to inform you that your paper is now accepting for publication in Biogeosciences.

While reading I identified a few potentially minor textual corrections:
- line 151: you write is in line with a depleted dissolvled inorganic carbon pool... This is correct but as written the reader may get the impression that you hint at 13C depleted DIC rather than small DIC pool. Try to reformulate.
- Line 332: same applies
- line 421: from -18 to 7% in adults... Is the minus sign correct here?
-line 435: On the other hand, where is the on the one hand? re-write.
-line 592: same applies

I am looking forward seeing this lasting paper being published.

With best regards, Jack Middelburg, Associate Editor