|This is a very interesting paper, and it surely deserve publication.|
I have only one “concern”: authors seem to suggest that this work is able to provide estimates of future fishery yield. They state this in the title of the paper, as well as in the title of section 5 and at the begininning of the conclusions (line 456). This study is a very valuable contribution in understanding the sensitivity of the ecosystem and of fishery to climate change and OA, but in my opinion it has far too many caveats to give plausible indication of trends. Authors themselves are very honest and transparent on these caveats and limitation, for instance at line 164 “More observations on a size spectrum scale are necessary to allow for any quantitative application of the size-based model” (and more during the discussion). My suggestion would be to be more cautious and talk about sensitivity of fishery yields in shelf water, rather than potential future yields. The latter would require in my opinion a more comprehensive consideration of the impact of climate change and OA on sehlf sea ecosystem.
few minor comments
Line 92: 1DV : what V stays for? Vertical?
Line 93: a space between water and column is missing
section 2.3: Authors point out that mesozooplankton overlap in size with the HTL model. However they do not highlight that also the benthic community represented in ERSEM-BFM partly overlap with the one described by the HTL model (e.g. deposit feeders). While I understand that given the different structure of the model, avoiding both of this overlapping it's really difficult, authors should discuss how this overlapping could impact the outcomes
line 150: what are these calibration factors?
Figure 2: is the model being validated on the annual mean, or the observed dataset is able to describe seasonal variability as well?
Line 163: it is not entirely clear to me what authors mean when they say that that high correlation coefficients reflect “the general size-based structure of the marine ecosystem and the small geographic area”.
Tables 4,5,6: I would suggest to explain in the caption what T and Act. stay for (I assume T is climate only scenario and Act. Stays for all active, but having in the caption would make more immediate to interpret the table
Tables 4, 5,6: my understanding is that the rows “fish” and “detritivore” refer to the changes in the total biomass of fish (and detritivore) simulated by the model, while “fish yield” represents the catches. If my interpretation is correct than I would suggest to change the name of the first column from “fisheries biomass” to “HTL biomass” or similar.
section 3. the title “effects on lower trophic levels” is quite misleading, because it suggests that here only impacts on LTL is described while lines 240-246, 258-265, 285-291 are all about fish and fishery. I understand that authors want to refer to their scenario definition, what about “Upscaling OA impact on nitrification”? Similarly for section 4 where I suggest something on the line of “Upscaling OA impact on detritivore growth”
Line 381: Artioli et al BGD 2013 has been published as Artioli et al., biogeosciences, 2014
line 388: As authors state later in the discussion (line 443-444), changes in circulation patterns is not the only way for global impact of climate change to affect local environment.
figures 3,4,5: I acknowledge that authors decided to keep the current format of the picture. I suggest authors to highlight which difference the bar plots (a and b) are showing. I guess is the difference between 1979-2008 and 2069-2098, however it would be clearer if they write it in the caption for a and b