Dear authors:
I have now received two reviewers comments on your paper and read through your reply to the reviewers' comments. It is obvious that particularly one reviewer is very critical about the original paper. As you indicated in your reply, you are willing to address the reviewers concerns in a revised version of the paper. Particularly, I ask you to incorporate the reviewers' comments in the revised version of the manuscript and do a thorough revision including an expansion of the analyses including also large rivers. Along with the revised manuscript please provide a statement how you addressed the reviewers' concerns in the revised version. The revised manuscript will be sent out to the reviewers again.
Looking forward to receiving a thoroughly revised manuscript.
Best wishes, Gerhard Herndl

Dear authors:
I have now received two reviewers' comments on your revised manuscript. As you can see, the two reviewers are very different in their opinion on scientific merit of the paper. While reviewer 1 finds it acceptable for publication, reviewer # 2 expresses major concerns on the quality of the paper and offers substantial criticism. After reading through the manuscript myself, I find that reviewer #2 has made some major and important points in his/her evaluation. Hence, I cannot accept publication of the paper in its present form, unfortunately. I do recommend that you take the comments of reviewer #2 seriously and address his/her concern adequately in a revised form of the manuscript. Alternatively, you might submit the manuscript to a more specialized journal and withdraw it from Biogeosciences.
If you consider a re-submission to Biogeosciences, please state point by point how you addressed the reviewer's concerns on the manuscript.
Sincerely yours, Gerhard Herndl

Dear authors:
please find attached a reviewer comment on the revised version of manuscript. Although the reviewer acknowledges that the paper is now potentially acceptable for publication, the reviewer also notes that there are still a number of awkwardly phrased sentences and apparently wrong Figure indications in the text among other issues.
Hence, I ask you to carefully go through the manuscript again, check the Figures and the references to them in the text and amend the text as indicated by the reviewer. Please let me have the revised manuscript at your earliest convenience.
Best wishes, Gerhard Herndl

Dear authors:
I have now gone through the revised manuscript. While the reviewer comment have been adequately addressed, I realized that throughout the manuscript the units are wrong! you frequently write "m(icro)m/L" this is the abbreviation of micrometer; please change that to "m(icro)M" or alternatively to "m(icro)mol L^-1; microM/L would also be wrong!
Fig. 12: units missing

please change this throughout the text including the figures.
Once this is done please submit the corrected manuscript again.
Best wishes, Gerhard Herndl