Luyao and co-workers,

two experts have evaluated your manuscript and both come to rather similar conclusions: the data itself are interesting, yet both consider your discussion rather poorly. They have provided ample ideas on how to improve the manuscript and on this specific level, your answers seems to indicate that potential revisions from your side would tackel these problems. In addition the reviewers comments, I was missing a more extrapolative character of your MS. What do we learn from this rather specific Swiss lake and how can we apply this to other lakes in hte region and most importantly beyond. At the moment, the study is very much on a local level. While this is not bad, it is more in the sphere of interest of local journals. In conclusion, I would consider a revised version of your MS given that the reviewers criticism (which I fully agree with) is addressed adequately and if you can extrapolate from your case study to a more general/global level.

With the best wishes, Helge Niemann

Dear Luyao Tu,

the second round of revisions was more positive and I would thus like accept your MS pending some technical/minor revisions. Please follow the suggestions by the reviewers (listed below).

With the best wishes, Helge Niemann



Reviewer concerns:
The authors have appropriately addressed all comments and suggestions. I add some minor suggestions that may help improving the text:

Line 13: add “… on short time scales in shallow lakes”
Line 14: replace "eutrophication" by "trophic state"
Line 15: replace "reduce" by diminish"
Line 18-19: replace “…provides information…” by “…provide information on the bentic P retention under the influence…”.
Line 21: delete “restoration”. Delete “the operation of”
Line 25: replace “hypolimnetic had better…” by “…sediment overlaying water was seasonally oxic”
Line 26-27: I suggest: “…in the hypolimnion and due to hypolimnetic water withdrawal increasing the P export out of the lake, net burial rates of total and labile P fractions decreased considerably in surface sediments.”

Abstract: As you mention "mixing regime" in the title you should explain in the abstract if and how hypolimnetic withdrawal affected the general character of the mixing regime.

Line 88-89: Omit sentence
Line 93: replace “has operated in the lake” by “ is in operation”

Line 103: replace “agricultural lands” by “farmland”
Line 106: “The mean annual AIR temperature…”
Line 115: replace “algae” by “algal”.
Line 115: What does "oxygenation condition" mean in this context?
Line 128: Does "afterwards" mean that bulk elements were determined in the remains of the sediment samples after the P extraction procedure? If not, please clarify!
Line 287: delete “relatively”.
Line 288: replace “during” by “”within”
Line 289: delete “reduced”
Line 316: replace “had” by “received”
Line 319-320: “…Lake Burgäschi was likely oligo- to mesotrophic.”
Line 331: replace “and” by “indicating”.
Line 332-333: delete “reveal strong positive trends in lake eutrophic levels. The significant eutrophication in Lake Burgäschi might have caused”
Line 334: delete “many”
Line 350: replace “during” by “in zones I to III, Mn and Fe varied mostly independent…””
Line 353: Specify: What sort of ratios?
Line 386: delete “completely”
Line 387: replace “circulation” by “overturn”. Delete “still”
Line 414: are retention and NBR not synonyms?
Line 457: If the epilimnic P concentrations exceed about 10 µg/l phytoplankton growth is likely not P limited.
Line 460: “… the high lake external P load into the epilimnion…”

Dear Luyao Tu,

thank you very much for the edits; I would hereby like to finally accept the MS.

Best wishes, Helge Niemann