Immediate Impact of the 2021 Harmful Algal Bloom in Southeast Hokkaido on the Rocky Intertidal Benthic Community and Its Spatial Variation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper, titled "Immediate impact of the 2021 harmful algal bloom in southeast Hokkaido on the rocky intertidal benthic community and its spatial variation," is an intriguing study that investigates the effects of a large-scale bloom of the harmful alga Karenia selliformis on diverse rocky intertidal benthic communities. The differences in the effect size of functional groups and regional groups after the large-scale bloom of K. selliformis presented by the authors clearly demonstrate which organisms were affected (by Effect Size), and I believe this approach is reasonable. Furthermore, this approach could be highly effective in evaluating the ecosystem impacts of Harmful Algal Blooms (HABs). However, there are some points of concern and suggested revisions.

   Firstly, graphs showing the population before and after HAB events for each functional group should be added. This would allow for a more objective evaluation and provide more information. (Additionally, to facilitate reasonable interpretation, displaying the number of samples is also necessary.)

  Secondly, molluscan grazers are mobile, so is there a possibility that their density could decrease independently of HABs due to their own movement?

  Lastly, the "decreasing rate" in Table 1 denotes a decrease, but the minus (-) sign in front of the value can be confusing. It should be clearly indicated (e.g., use a plus sign for increases and omit any sign for decreases).

 With these improvements, I believe this paper could be published in JMSE.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Generally, this manuscript needs to go into more detail about the actual toxins produced by the HAB, particularly in the introduction. Also, there several times that the text mentions that the algae species caused mortality, but doesn't the toxins cause the mortality? Finally, were there any new species discovered after the HAB event and what happened with the organism recovery?

Minor note, text line 376-379 has italics throughout the sentence.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

There was a good faith response to the review comments and subsequent revisions. We believe it is suitable for publication in JMSE.

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for responding to my comments.