Concentrations and Characteristics of Polybrominated Diphenyl Ethers (PBDEs) in Marine Zooplankton from the Gaoping Waters of Southwestern Taiwan

Round 1

Reviewer 1 Report

Authors should cite references properly. References have not been cited well in many places for example , page 2, line 57 and 58.

''[20] found that in comparison with other marine organisms 57 worldwide, PBDE concentrations in organisms from Bohai Bay were low '' This does not read well. Consider ''Wan et al [20] found that in comparison with other marine organisms 57 worldwide, PBDE concentrations in organisms from Bohai Bay were low.

Although the thrust of this study is on Concentrations and Characteristics of Polybrominated Diphe-1 nyl Ethers (PBDEs) in Marine Zooplankton, I believe the quality of the paper would have been enhanced by a more robust risk assessment evaluation of the data.

Author Response

Reviewer 1

Authors should cite references properly. References have not been cited well in many places for example , page 2, line 57 and 58. ''[20] found that in comparison with other marine organisms 57 worldwide, PBDE concentrations in organisms from Bohai Bay were low '' This does not read well. Consider ''Wan et al [20] found that in comparison with other marine organisms 57 worldwide, PBDE concentrations in organisms from Bohai Bay were low.

AUTHOR RESPONSE: We revised them. Thanks.

Although the thrust of this study is on Concentrations and Characteristics of Polybrominated Diphe-1 nyl Ethers (PBDEs) in Marine Zooplankton, I believe the quality of the paper would have been enhanced by a more robust risk assessment evaluation of the data.

AUTHOR RESPONSE: Thanks for reviewer’s suggestion. we added a result of non-linear relationships analysis among dominant taxa abundances and PBDE congeners concentrations of zooplankton (Figure 4) and some contents in the revised version.

Reviewer 2 Report

The paper is well written and structured. This study represents valuable infomration and results regarding PBDEs in marine zooplancton. Considering that the results of this study showed significantly high concentration of PBDEs, higher than in other areas, further investigations in this area should be related to sources of contamination but also to bioaccumulation, biomagnification and transport within the marine food web.

Author Response

Reviewer 2

The paper is well written and structured. This study represents valuable infomration and results regarding PBDEs in marine zooplancton. Considering that the results of this study showed significantly high concentration of PBDEs, higher than in other areas, further investigations in this area should be related to sources of contamination but also to bioaccumulation, biomagnification and transport within the marine food web.

AUTHOR RESPONSE: Thanks for your comments and suggestions. We agree your viewpoint. Indeed, further investigations in this study area focused on the biomagnification and transport in the marine food web are necessary. However, due to the limited cruise of the research ship, it is impossible for us to do that in the present study.

Reviewer 3 Report

Review for the paper "Concentrations and Characteristics of Polybrominated Diphenyl Ethers (PBDEs) in Marine Zooplankton from the Gaoping Waters of Southwestern Taiwan" by Hung-Yen Hsieh, Kuang-Ching Huang, Jing-O Cheng, Fung-Chi Ko, Pei-Jie Meng submitted to "JMSE".

General comment.

There is an increasing concern regarding the growing concentrations of various contaminants in aquatic environments worldwide. Global human activity has led to a several-fold increase in diphenyl ethers emissions into the oceans and rivers. In the environment, polybrominated diphenyl ethers may be considered chemicals of global concern, because of their long-range transport, subsequent bioaccumulation, and biomagnification in the marine food webs, and toxicity when reaching high concentrations causing adverse effects at higher trophic levels. While studies of the spatial distribution of PBDE in wildlife and seawater are quite extensive across several regions, knowledge of PBDE concentrations and dynamics for the coastal waters of Taiwan is scarce. Therefore, the present study may have good potential to be attractive for marine environmentalists dealing with aquatic toxicants and pollution of seawater in the coastal regions. Zooplankton can be recognized as one of the best indicators of marine pollution. Considering the key position of planktonic organisms in the aquatic food webs, data on the content of PBDE in their tissues provide a valuable base-line background for monitoring studies and further investigations in this field. The authors revealed high variability of total PBDE concentrations and concluded human activities to be the most responsible for enhanced levels of PBDE in zooplankton that may have postponed effects on higher trophic levels (invertebrates and fishes). Standard methods to collect samples and to treat the data were used in the study. The main results are visualized with relevant figures and tables. The data were interpreted in a clear manner and supported with relevant statistics. However, I feel that some parts of the ms should be revised and improved for better presentation of the main findings.

Specific remarks.

L28-33. Relevant references are needed.

L33. produced:. Delete semicolon.

L35. Consider replacing " According to [4], " with " According to Meironyté et al. [4], ".

L55. Consider replacing " from Baltic Sea " with " from the Baltic Sea ".

L80. Consider replacing " on August" with " in August".

L87. Consider replacing " of six different" with " at six different".

L94. Consider replacing " sampling station" with " sampling stations".

L114. Consider replacing " on the method of [33]" with " on the method by Welschmeyer [33]".

L132-133. Consider replacing " The preparation, extraction, and analysis procedures of [36,37] laid the foundation of the present study." with " The preparation, extraction, and PBDE determination were maid based on standard analytic procedures [36,37] .".

L139. Consider replacing " by [26]" with " by Ko et al. [26]".

L161.Clarify, which normalization was used.

L171. Consider replacing " much bigger" with " much higher".

Section 3.1. Environmental variables must be compared with previous published reports.

L225-228, 245-248. I suggest the authors round off the mean abundances of zooplankton to the nearest whole numbers.

L245-248. I suggest the authors round off the mean abundances of zooplankton and RA to the nearest whole numbers.

L319-326, 413. I suggest the authors round off the PBDE concentrations in zooplankton to the nearest whole numbers. Also, L19.

L337-339, 344. I suggest the authors round off the BDE concentrations in zooplankton to the nearest whole numbers.

L391. PBDEs: Delete semicolon.

L394. Consider replacing " distribution:  " with " distribution -  ".

L407. Consider replacing " by [13]" with " by Kelly et al. [13]".

Author Response

Reviewer 3

General comment.

There is an increasing concern regarding the growing concentrations of various contaminants in aquatic environments worldwide. Global human activity has led to a several-fold increase in diphenyl ethers emissions into the oceans and rivers. In the environment, polybrominated diphenyl ethers may be considered chemicals of global concern, because of their long-range transport, subsequent bioaccumulation, and biomagnification in the marine food webs, and toxicity when reaching high concentrations causing adverse effects at higher trophic levels. While studies of the spatial distribution of PBDE in wildlife and seawater are quite extensive across several regions, knowledge of PBDE concentrations and dynamics for the coastal waters of Taiwan is scarce. Therefore, the present study may have good potential to be attractive for marine environmentalists dealing with aquatic toxicants and pollution of seawater in the coastal regions. Zooplankton can be recognized as one of the best indicators of marine pollution. Considering the key position of planktonic organisms in the aquatic food webs, data on the content of PBDE in their tissues provide a valuable base-line background for monitoring studies and further investigations in this field. The authors revealed high variability of total PBDE concentrations and concluded human activities to be the most responsible for enhanced levels of PBDE in zooplankton that may have postponed effects on higher trophic levels (invertebrates and fishes). Standard methods to collect samples and to treat the data were used in the study. The main results are visualized with relevant figures and tables. The data were interpreted in a clear manner and supported with relevant statistics. However, I feel that some parts of the ms should be revised and improved for better presentation of the main findings.

Specific remarks.

 L28-33. Relevant references are needed.

AUTHOR RESPONSE: We added an appropriate literature. Thanks.

L33. produced:. Delete semicolon.

AUTHOR RESPONSE: We deleted the semicolon. Thanks.

L35. Consider replacing " According to [4], " with " According to Meironyté et al. [4], ".

AUTHOR RESPONSE: We revised it. Thanks.

L55. Consider replacing " from Baltic Sea " with " from the Baltic Sea ".

AUTHOR RESPONSE: We revised it. Thanks.

L80. Consider replacing " on August" with " in August".

AUTHOR RESPONSE: We revised it. Thanks.

L87. Consider replacing " of six different" with " at six different".

AUTHOR RESPONSE: We revised it. Thanks.

L94. Consider replacing " sampling station" with " sampling stations".

AUTHOR RESPONSE: We revised it. Thanks.

L114. Consider replacing " on the method of [33]" with " on the method by Welschmeyer [33]".

AUTHOR RESPONSE: We revised it. Thanks.

L132-133. Consider replacing " The preparation, extraction, and analysis procedures of [36,37] laid the foundation of the present study." with " The preparation, extraction, and PBDE determination were maid based on standard analytic procedures [36,37] .".

AUTHOR RESPONSE: We revised it. Thanks.

L139. Consider replacing " by [26]" with " by Ko et al. [26]".

AUTHOR RESPONSE: We revised it. Thanks.

L161.Clarify, which normalization was used.

AUTHOR RESPONSE: We deleted the sentence of “Prior to ANOVA the all data were normalized.”

L171. Consider replacing " much bigger" with " much higher".

AUTHOR RESPONSE: We revised it. Thanks.

Section 3.1. Environmental variables must be compared with previous published reports.

AUTHOR RESPONSE: Thanks for reviewer’s suggestion. we added some contents in the revised version.

L225-228, 245-248. I suggest the authors round off the mean abundances of zooplankton to the nearest whole numbers.

AUTHOR RESPONSE: We revised them following the reviewer’s suggestion. Thanks.

L245-248. I suggest the authors round off the mean abundances of zooplankton and RA to the nearest whole numbers.

AUTHOR RESPONSE: We revised them following the reviewer’s suggestion. Thanks.

L319-326, 413. I suggest the authors round off the PBDE concentrations in zooplankton to the nearest whole numbers. Also, L19.

AUTHOR RESPONSE: We revised them following the reviewer’s suggestion. Thanks.

L337-339, 344. I suggest the authors round off the BDE concentrations in zooplankton to the nearest whole numbers.

AUTHOR RESPONSE: We revised them following the reviewer’s suggestion. Thanks.

L391. PBDEs: Delete semicolon.

AUTHOR RESPONSE: We deleted semicolon. Thanks.

L394. Consider replacing " distribution:  " with " distribution -  ".

AUTHOR RESPONSE: We revised it following the reviewer’s suggestion. Thanks.

L407. Consider replacing " by [13]" with " by Kelly et al. [13]".

AUTHOR RESPONSE: We revised it. Thanks.

Round 2

Reviewer 1 Report

Authors have satisfactorily revised their manuscript to enhance the quality.

I would like to recommend it for acceptance now.