Screening for Organic Pollutants in the Black Sea Turbot (Scophthalmus maeoticus)

Round 1

Reviewer 1 Report

Comments to the Authors

The paper ‘Screening for Persistent Organic Pollutants in the Black Sea turbot (Scophthalmus maeoticus)’ aims to evaluate POPs concentrations in its main tissues. In this paper, POPs - polycyclic aromatic hydrocarbons, organochlorine pesticides and polychlorinated biphenyls were determined in water, sediment, and turbot tissues (muscle tissue, gills, gonads, and liver) to explore their accumulation level. The manuscript deals thus with an important topic relevant to the environment and humans. We need such an integrative approach to assess the health status of any explored aquatic area. The paper is well-written and the language is of good quality. In my opinion, the writing manner is very effective in the uptake of prominent and key points of each research work, herein, the presentation way of the manuscript is very well and simple. The background provides a sufficient literature review, the methodology is sound, results are explanatory and well-discussed. Overall, a good read.

Abstract, introduction, and conclusions:

These sections are well-written and focused on the main questions the authors intend to explore. However, in the Conclusions sections, the authors did not presented the answers to their questions. In these two sections, the authors explained why they used the applied approach and what are their findings which could, in my opinion, improve the quality of future studies in biomonitoring of the aquatic ecosystems. The statistical side must be introduced to support the trends observed.

 

To sum up, I found the paper very original and interesting, so I support its publication in the journal after a revision focucing especially on the statistical processing that I think might increase a the quality of the manuscript. All my detailed comments and suggestions are reported below:

 

 

Specific comments :

-lines 188-197 : please support by adding references.

- Fig 4 : replace photos by better ones. Separate them.

-lines 218-224 and 227-237 : please support by adding references.

-Fig 7 (and all figures): are you presenting average values ? if yes .. how many resplicates you used ? compare the means by using statistical tests (ANOVA and eventually HSD Tukey test)

-Fig 12 : Which software you used ? Statistica ?

-Avoid using ‘we’ and ‘our’ in the main text. Instead use the passive voice.

-The conclusions section must be rewritten and the main results obtained summarized.

 

 

Author Response

Dear Reviewer,

Thank you for your thorough evaluation of our paper and the feedback you provided. As a result, we have extensively revised the paper to address all of the comments, corrections, and suggestions. We believe that these revisions have greatly enhanced the quality of the paper. We described in the attachment the major modifications made to address the primary weaknesses identified by the review.

Yours sincerely,

The Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript reported levels of PAHs, OCPs, and PCBs in fish, water, and sediment from Black Sea. The method used to extract and quantify of PAH, OCPs, and PCBs was not right. Therefore, the results obtained are highly suspicious. PAH was extract with MeOH. PAH is hydrophobic substance. How can you extract them with MeOH? The results is not corrected. The concentration up to ug/g dry weight. This is impossbble.   

Author Response

Dear Reviewer,

Thank you for your thorough evaluation of our paper and the feedback you provided. As a result, we have extensively revised the paper to address all of the comments, corrections, and suggestions. We believe that these revisions have greatly enhanced the quality of the paper. We described in the attachment the major modifications made to address the primary weaknesses identified by the review.

Yours sincerely,

The Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript entitled “Screening for Persistent Organic Pollutants in the Black Sea turbot (Scophthalmus maeoticus)” is important study the presence and the severity of pollution with POPs and it has become evident with their detection in areas such as the Arctic Zone, where they have never been used or produced. Their use in industrially developed contries has been realized as coolants, lubricants, hydraulic fluids, plasticizers, and additives in dyes. PCBs studied in this work are PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, PCB180. Overexploitation and habitat loss and degradation have recently been identified as major threats to marine fish biodiversity, and as the impacts of climate change have become more apparent, pollution has been considered a significant threat risks to both wildlife and for human health. 

The introduction is relevant but must include new references. The discussion, in the light of results and knowledge, is relevant.  

Based on these comments, I recommend a moderate revision of analytical aspects of this manuscript before final decision about its acceptance. 

Minor comment:

Introduction: 

L28-174: rewrite this part with new bibliographical references, there is only an ancient research (El-Shahawi, M. S., et al.; 2015) and (Fillaudeau, L., et al.; 2006); (Pitcher, T. J., et al.; 2002) 

It’s necessary to insert new references about the toxicological tests have demonstrated the toxic effects of endocrine exposure of pollutants, reproductive system, immune system, nervous system, cardiovascular, fetus toxicity, cellular toxic effects… as well as being a risk factor for the onset of various diseases such as anemia, mononucleosis, see below reference:

Francesco Fazio, Concetta Saoca, Gregorio Costa, Alessandro Zumbo, Giuseppe Piccione, Vincenzo Parrino. Flow cytometry and automatic blood cell analysis in striped bass Morone saxatilis (Walbaum, 1792): A new hematological approach, Aquaculture 513 - 734398 (2019).

Basova Marina, Svetlana Krasheninnikova, Parrino Vincenzo - Intra-Decadal (2012–2021) Dynamics of Spatial Ichthyoplankton Distribution in Sevastopol Bay (Black Sea) Affected by Hydrometeorological Factors. ANIMALS; 12, 3317; https://doi.org/10.3390/ani12233317; (2022).

2. Materials and Methods: 

Was the detected concentration in the water and sediments often high due to the PCB emission by industries that use these substances for industrial purposes in their production processes and could this have contaminated agricultural land and surface and groundwater? Is there any previous research in these areas??……. if not, clarify this aspect better!

Please insert approval to use organism for research: Statement of Ethics Approval

3. Results: 

All sampled fish were clinically healthy?

Please described the absence of lesion.

Please the units of measure for the average weight of fish should be checked. 

Please the guidelines followed to carry out the validation should be specified.

Statistical:

The statistical analysis used is appropriate.

4. Discussion:

The authors should be reduce this part, please the results shown in figures.

This part is very long, reduce it and discuss only the obtained results.

Did the authors think about expanding the work to include larger fish?

Figures and Tables:

Check it out in all legend… (insert the species name of fish)

5. Conclusion:

Despite the presence of pollutants which also indicates a possible bioaccumulation in the food chain, fishing is allowed and it is important to underline the continuous monitoring for human health... please explain this aspect better.

 

Author Response

Dear Reviewer,

Thank you for your thorough evaluation of our paper and the feedback you provided. As a result, we have extensively revised the paper to address all of the comments, corrections, and suggestions. We believe that these revisions have greatly enhanced the quality of the paper. We described in the attachment the major modifications made to address the primary weaknesses identified by the review.

Yours sincerely,

The Authors

Author Response File: Author Response.pdf

Reviewer 4 Report

Submitted for review "Screening for Persistent Organic Pollutants in the Black Sea 2 turbot (Scophthalmus maeoticus) “ The article is a very good scientific work. It's a good read, interesting. There are many methodological details, which will certainly be of interest to readers working with similar equipment or matrices. I have only few comments to consider:

I don't know if chromatograms from a gas chromatograph are needed, so I would consider removing it.

In the Results chapter, I don't like the numerical format of the results, is it necessary to provide such a large number of uncertain digits, such high accuracy. Certainly, the reception of these results would be better if the numbers were rounded to two/three digits after coma point.

I am also missing information about the quantification limit. Are these numbers, e.g. :0.004, the limit of determination? If so, please indicate it in the text.

Please improve the quality of the images, e.g. Figure 9,10,11. Axis captions in the chart are fuzzy. In addition, the charts from the statistical program have terrible quality, they are illegible.

In general, the work is good, it needs a few minor corrections. After minor improvement, it will be suitable for publication in this scientific journal.

Author Response

Dear Reviewer,

Thank you for your thorough evaluation of our paper and the feedback you provided. As a result, we have extensively revised the paper to address all of the comments, corrections, and suggestions. We believe that these revisions have greatly enhanced the quality of the paper. We described in the attachment the major modifications made to address the primary weaknesses identified by the review.

Yours sincerely,

The Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I insistant my view that the result of this manuscript is not trustworthy. It's impossible to extract PAH with MeOH as solvent。 Meanwile, it also impossible that the OCP or PCB concentration reach up to 150 ug/g dry weight and 1200 ug/g dry weight. The concentrations of OCPs and PCBs generally was at levels of ng/g lipid weight. The lipid content were generally 1% of dry weight, which means the OCP concentration can reach to 120000 ug/g lipid? Exposure experiment in the labrotary using spiked food did'nt reach this high concentration . It's would be inconceivable for PCB levels in sea water fish to 15000 ug/g lipid or 15000000 ng/g lipid. Therefore, I do'nt recomment publish this manuscript.

Author Response

Dear Reviewer,

Attached you can find our answer. 

Best regards

 

Author Response File: Author Response.pdf