Latitudinal Dynamics of Vibrio along the Eastern Coastline of Australia
, Nachshon Siboni 1, William L. King 2, Varunan Balaraju 1, Anna Bramucci 1 and Justin R. Seymour 1,*
Round 1
Reviewer 1 Report
The subject of this manuscript is very interesting and important for the safety of water serving people and animals. In my opinion, this manuscript gets thematically to the WATER journal and therefore should be allowed to be published in this journal.
A valuable advantage of this research is to demonstrate correlation between northern and southern locations, temperature and salinity, as well as ecological relationships with phytoplankton.
The authors could still try to develop a statistical model describing the influence of the above -mentioned factors on pathogenic and non -patient Vibrio species taking into account climate change (e.g. water temperature changes). The conclusion resulting from such modelling would be valuable.
Author Response
Reviewer 1
The subject of this manuscript is very interesting and important for the safety of water serving people and animals. In my opinion, this manuscript gets thematically to the WATER journal and therefore should be allowed to be published in this journal.
A valuable advantage of this research is to demonstrate correlation between northern and southern locations, temperature, and salinity, as well as ecological relationships with phytoplankton.
The authors could still try to develop a statistical model describing the influence of the above-mentioned factors on pathogenic and non -patient Vibrio species taking into account climate change (e.g., water temperature changes). The conclusion resulting from such modelling would be valuable.
Reply: We sincerely thank the reviewer for their positive comments on our work. In relation to developing a statistical model to describe the influence of water temperature changes on Vibrio spp. we feel that our data does not fit the scope, or criteria to develop a robust model for accurate predictions of Vibrio spp. abundances in future climate change-induced scenarios. Moreover, robust models have already been made by Trinanes and Martinez-Urtaza, (2021) and Baker-Austin, (2013). To acknowledge the usefulness of these models, we have added the following text to our discussion (P27. L530) “ Models of future SST scenarios predict 38000 km of new coastal areas by 2100 being suitable for Vibrio growth as a result of climate change (Trinanes and Martinez-Urtaza, 2021), as well as an increase in Vibrio cases of 1.93 times for every 1 °C increase in SST (Baker-Austin et al., 2013). This is particularly concerning for Australia, whereby the SST is predicted to rise 1.5 °C – 3 °C by 2070, translating to a 2.9 – 5.8 times increase in the abundance of Vibrio spp in Australian waters”.
Reviewer 2 Report
The manuscript is accepted for publication.
Author Response
Reviewer 2
The manuscript is accepted for publication.
Reply: We sincerely thank the reviewer for their positive assessment of our work.
Reviewer 3 Report
The present study describes the patterns of Vibrio spp. Along the eastern coastline of Australia and observed correlations with latitude, temperature and salinity. The data provide new insights in the dynamics of pathogenic Vibrio spp linked to environmental factors, which might help to predict future outbreak scenarios. I recommend publication after a minor revision.
Specific comments
Introduction:
L36: Is there also a more recent study as Roy et al. 1998 is quite old
L50-61: What about environmental Vibrio species (Independent of animals) and are they particle-asscociated or free-living?
L91-101: Could you please describe in more detail what is new in the present study in comparison to the previos studies (L94-97) and mention when and where did you sampled?
Methods:
L104-107: Did you take the samples at each site only once, so that the samples from each site are from different dates? If so, what about temporal dynamics? Are the differences in Vibrio spp. abundance and diversity due to temporal changes?
Results:
3.3. (L272) I do not know if the heading is approiate as you do not describe the diversity and the bacterial communitiy composition. You mainly mention diversity indices and how they differ as well as some indicator groups.
Figure 2 and L286-291: Are the colours of North and South exchanged? There are squares instead of minus‘ on the axes.
Figure 4: What unit on the axis? Is it possible to increase the font size and choose darker colours?
Figure 5: What are these squares in front of the values in the R value legend? Negative values? I guess you can remove them.
Discussion:
Vibrio spp (including pathogenic ones) are known to be part of biofilms on microplastic particles and play an important role in this global health issue. I suggest to additionally discuss your data (in a few sentences) linking to the microplastic problem.
Author Response
Reviewer 3
The present study describes the patterns of Vibrio spp. Along the eastern coastline of Australia and observed correlations with latitude, temperature, and salinity. The data provide new insights in the dynamics of pathogenic Vibrio spp linked to environmental factors, which might help to predict future outbreak scenarios. I recommend publication after a minor revision.
Reply: We would like to thank the reviewer for taking the time to assess our work. We are grateful for their feedback and their helpful suggestions.
Specific comments:
Introduction:
L36: Is there also a more recent study as Roy et al. 1998 is quite old.
Reply: We would like to thank the reviewer for their suggestion. We have now added the reference (Raes et al., 2018). Raes, E.J., Bodrossy, L., van de Kamp, J., Bissett, A., Waite, A.M., 2018. Marine bacterial richness increases towards higher latitudes in the eastern Indian Ocean. Limnology And Oceanography Letters 3, 10–19. https://doi.org/10.1002/lol2.10058
L50-61: What about environmental Vibrio species (Independent of animals) and are they particle-associated or free-living?
Reply: We thank the reviewer for their insightful comment. We have now changed the text (P3. L54) to read “Within coastal and estuarine ecosystems, members of the Vibrio genus, which can be particle associated (Liang et al., 2019), or free-living (Li et al., 2020), are notable members of natural bacterial assemblages because of their often-important ecological relationships”.
L91-101: Could you please describe in more detail what is new in the present study in comparison to the previous studies (L94-97) and mention when and where did you sampled?
Reply: We thank the reviewer for their comment and have now changed the text (P5. L99-L102) to read “we aimed to determine the patterns of abundance and diversity of the Vibrio community during the Australian summer using the high throughput hsp60 gene amplicon sequencing assay to characterise the Vibrio community across a large latitudinal transect spanning the entire eastern coastline of Australia, one of the largest latitudinal Vibrio ecology gradients studied to date.” And (P5. L105) “Previous studies ... but neither of these studies have investigated Vibrio ecology on such a large scale.”
Methods:
L104-107: Did you take the samples at each site only once, so that the samples from each site are from different dates? If so, what about temporal dynamics? Are the differences in Vibrio spp. abundance and diversity due to temporal changes?
Reply: We thank the reviewer for their insightful comment. Unfortunately, we were unable to sample each site more than once. While the samples were taken on different dates, we accounted for these differences by sampling in the same season, during summer, within a period of 48 days. To clarify this, we have changed the text (P6. L113) “Water samples were collected once each from... over a period of 48 days”. We have added this point to the discussion (P24. 458) “Another potential reason for these differences may be due to temporal changes, which were not accounted for in this study, with each site being sampled once within a period of 48 days during the Australian summer.”
Results:
3.3. (L272) I do not know if the heading is appropriate as you do not describe the diversity and the bacterial community composition. You mainly mention diversity indices and how they differ as well as some indicator groups.
Reply: We thank the reviewer for their comment. We have changed the title to read “3.3 Bacterial Community Analysis”.
Figure 2 and L286-291: Are the colours of North and South exchanged? There are squares instead of minus‘ on the axes.
Reply: We thank the reviewer for picking up on this error. The minus signs have been corrected. The colours of North and South are not exchanged. As per the legend, the red circles represent Northern samples, and the blue circles represent Southern samples.
Figure 4: What unit on the axis? Is it possible to increase the font size and choose darker colours?
Reply: We thank the reviewer for identifying this error. We have now changed the colour scheme and added the unit to the axis.
Figure 5: What are these squares in front of the values in the R value legend? Negative values? I guess you can remove them.
Reply: We thank the reviewer for picking up on this error. We have now corrected the box issue, as they were indeed intended to be minus signs.
Discussion:
Vibrio spp (including pathogenic ones) are known to be part of biofilms on microplastic particles and play an important role in this global health issue. I suggest to additionally discuss your data (in a few sentences) linking to the microplastic problem.
Reply: We thank the reviewer for this insightful suggestion. We have now added the following line to the discussion (P24. L.453) “ While not examined in this study, in a recent study, Vibrio spp. were discovered to form biofilms on microplastic particles and, their occurrence on these microplastics was correlated to proximity to major cities (Kesy et al., 2021),which may explain high levels of Vibrio bacteria at these locations, which are all highly urbanised.”
