Combining Methods to Better Estimate Total Fish Richness on Temperate Reefs: The Case of a Mediterranean Coralligenous Cliff
Round 1
Reviewer 1 Report
Editorial Office of Journal
Journal of Marine Science and Engineering
Comments for review of manuscript: Combining methods to estimate total fish biodiversity on reefs: 2 an example from a single coralligenous cliff
The manuscript concern of on the evaluation of the use of two methods to assess the species richness of fish in the coralligenous cliff community in the area of the island of Hvar channel, Adriatic Sea. The study of this type of ecosystem is extremely difficult due to the very large diversity of habitats and the conditions prevailing in them. It requires very good technical preparation and practical experience. There are known research methods for this type of habitat, but due to the above arguments they are significantly inaccurate. In reviewed paper Authors tried to combine methods to optimize the results of the assessment of the species richness of fish in this type of habitat. In my opinion, in general, the paper touches on an interesting topic, but it is prepared with many shortcomings and in my opinion requires significant corrections. Nevertheless, the subject matter is interesting and with an appropriate description, it can be a valuable source of information.
Below are some comments on the manuscript under review.
Title
In my opinion, the title needs to be changed. The present title is too general and does not say about the content of the work. I would propose to include methods for assessing fish communities. Moreover, I would not use the word "biodiversity", as the Author/s mainly examined species richness (with elements of species traits). Biodiversity is a slightly broader term and requires the assessment of diversity indicators. I would suggest clarifying the title of the paper. In the whole paper (including abstract, line: 14) I would not use the term ".. a complete assessment of fish assemblages ...." because we never that know in the natural science research.
Introduction
Too long chapter. I propose to shorten and focus on the methods of researching these ecosystems in terms of fish. There is lack of overview of knowledge about this type of ecosystems, how many fish species, with what assessment methods, what is the effectiveness of the methods, etc. The aim of study is poorly justified. It should be more justified e.g. the text from the discussion - first paragraph. In addition, the aim should be specifically formulated - what the Authors wanted to tested, achieve.
In the paragraph about the aim of the study, the phrase "highest fish biodiversity and population density" has nothing to do with the data from the reviewed study, which which only concern the species composition, i.e. species richness. In addition, there isn’t a word about fish densities in all of this paper.
Materials and methods
As the Authors themselves describe, the data of research has already been partially published in two papers (references 12 and 16 from the manuscript). I would propose to specify what exactly was used in these articles, and what is new in the present manuscript. Too general data on sampling times. We do not know about this in the current version of the manuscript. Moreover, it is somehow worth justifying that the data of the compared methods come from different years (3 years interval).
No detailed information about transects (DVT method and modified DVT).
Were three methods used as described by the authors at the beginning of this chapter? In my opinion DVT and modified DVT is one method only adapted to depth. The results of these methods (DVT and DVT modified) are combined later in the manuscript. Maybe there should be two methods?
There is no detailed description of how to the specific trophic level fish were classified.
Lines 174 - 175– quotation: ”… while SAM was performed from 15 m ..? …. 62 m?
Lines 161 - 162 - no detailed description of what the square is? Maybe the sentence "The total number of performed squares was 54." should be moved after the description of the method e.g. line 169?
In my opinion the sentence from the methodology (lines 169 - 171) should be changed and Table 1 not be quoted. It is enough to say that the results are summarized separately. The Table 1 is the result table and should be cited in the Results section.
Data analysis and some methodology descriptions do not differentiate DVT from DVT and DVT modified - I wrote about it before – two methods.
Line 191 - 193 - ok I understand. The methods are incompatible, but the results can be presented because it may be important and interesting for other authors of articles of this topic.
In my opinion, it is worth describing more details in the methods of analysis, such as statistical analysis, what were the factors of the analysis, what were compared with what, etc. Maybe it is worth using a two-factor analysis (method and species traits)?
More details about of analysis of frequency. No information on how it was calculated.
I suggest not to quote result table 2 in the methodology !!!
Figure 1- very similar to the previous articles by these authors (references 12 and 16). This is not surprising because the study concern the same area and scope of research. So mayby give up this map and quote the earlier papers with that figure 1.
Results
The fish species that have been observed during the dives are described, and both methods have not shown them. Maybe it is worth writing something about it in the methodology?
Line 231 - I propose a sentence not to start with the "%".
I would suggest putting density values in the results, maybe in different units, depending on the method. I my opinion this would provide important information.
Table 3 - subtitle description not needed in the title of the table. They are in the table. Unnecessary duplication of headings.
In the Results chapter statistical differences and not the obtained results - values were described. In my opinion it is incorrect. Statistical differences are only evidence of differences between the values (see lines 246-248, 251-253 and more). In my opinion, the results chapter should be rewritten.
Discussion
I think, the first paragraph (from the lines 282-296) perfectly justifies the research undertaken and should be included in the Introduction.
Lines 295 - 296 - species richness not biodiversity.
In the Discussion chapter, we have information about visual limitations and there is not word about it in the methodology or the results (lines 302 - 304).
The part of the Discussion without reference to literature sources (lines 323 - 342). Perhaps it is worth discussing this information with the literature on these methods.
Line 346 - “…. the aim is to determine total fish biodiversity…. " - species richness to be exact.
The discussion does not answer the question posed for the purpose of research - it is known that two methods should be more effective than one method.
In this chapter no reference to other publications comparing how many species were different methods, what species were similar or different, what species richness, possible density depending on the method, etc.
The chapter needs to be improved.
After reviewing this paper I suggest reject of the manuscript in its present form. I believe that after taking into account reviewers comments, redrafting paper and maybe another review it could be published in the Journal of Marine Science and Engineering as a research article.
Author Response
Review report 1: all the comments and suggestion of reviewer 1 have been incorporated in the text with the following exceptions:
Line 191 - 193 - ok I understand. The methods are incompatible, but the results can be presented because it may be important and interesting for other authors of articles of this topic.
Reply: we feel that there is no sense to provide the quantitative data and not analyzing them later, which is not possible as explained in the ms.
In my opinion, it is worth describing more details in the methods of analysis, such as statistical analysis, what were the factors of the analysis, what were compared with what, etc. Maybe it is worth using a two-factor analysis (method and species traits)?
Reply: It is not possible to perform suggested analysis without quantitative data.
Figure 1- very similar to the previous articles by these authors (references 12 and 16). This is not surprising because the study concern the same area and scope of research. So mayby give up this map and quote the earlier papers with that figure 1.
Reply: There was no map figure in reference 19, and the map is different from the map in reference 15, although it covers the same geographic area, so we prefer to keep the original map as it is.
I would suggest putting density values in the results, maybe in different units, depending on the method. In my opinion this would provide important information.
Reply: It is not possible to provide density without quantitative data.
In the Results chapter statistical differences and not the obtained results - values were described. In my opinion it is incorrect. Statistical differences are only evidence of differences between the values (see lines 246-248, 251-253 and more). In my opinion, the results chapter should be rewritten.
Reply: The compared values are presented in the Table 3, and the most important values were repeated in the text. Regarding test statistics, contrary to other test, Fisher exact test gave probability as the only outcome calculated from the values.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
See attached table
Comments for author File: Comments.pdf
Author Response
Review report 2: all the comments and suggestion of the reviewer 2 have been incorporated in the text. The only exception is the comment on tables and suggestions that might be placed in an annex at the end of the paper. The length of the tables is due to the high number of species which are essential for future comparisons, thus we prefer to keep the tables as the integral part of the manuscript and its results.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The most of my comments were taken into account by the Authors. Responses to my comments in review are sufficient.
Author Response
Reply to a member of the editorial board:
It is impossible to compare the quantitative data from the transect method where each transect has an area of 250m2 and from the square method where the area is 1m2. Thus, it makes no sense to provide the quantitative data and not to analyze them later. The point is that any kind of analysis which uses quantitative data is useless in this case as it does not give any kind of reliable result or info.
