Dear Dr. Munkes
Thank you for your submission and preliminary response to the reviewers.

Both reviewers are generally positive but make a number of significant suggestions for improvement.

Of key importance, both reviewers note that you cover both the reductionist approach of modellers and the more complex view of ecologists, but that you have not reconciled or discussed the two approaches in enough detail. Are there key areas where increased complexity is needed to better reproduce key observations? A key purpose of reviews is to synthesise information and suggest future directions and it is important you address this point in some detail.

Please revise your manuscript addressing the reviewers comments and I will consider it further with input from one or both or the reviewers.
Regards
Perran Cook

Dear Dr. Munkes
Thanks for your revised manuscript. I note that you mention the changes but do not paste them into your response letter. To make it easier for me and the reviewers to assess your response without having to continuously refer back and forth between the document, I ask that you paste your change into the response letter.

For example
As suggested by the reviewer we have expanded on the reason for xyz.
Pg XX line YY now reads "abc led to the discovery of xyz"

Regards
Perran Cook

Dear Dr. Munkes

Thank you for your comprehensive revisions of the manuscript. It has been greatly improved and now makes an important and timely synthesis of the the current understanding of the factors controlling cyanobacteria in the Baltic.

Reading through the manuscript I noted the following typos, please address these before final acceptance.

Regards
Perran Cook

Pg2 Line 10 This sentence is unclear. …are motivated by concerns about low-oxygen condition….

Pg 18 line 14 reword to ‘there is little evidence’

3.3.1 salinity constraints