When and Where Did They Strand? The Spatio-Temporal Hotspot Patterns of Cetacean Stranding Events in Indonesia

Round 1

Reviewer 1 Report

This article report relevant information about the stranding events in Indonesia. The reported data can be used to improve the stranding assistance of cetacean. However, the discussion is not supported by scientific literature, as in the whole section only three references are made. 

I believe that this report can be strongly condensed, as relevant epidemiological information about cetacean health is presented, but the discussion must be improved in a way that the readership could benefit from it. The strategical areas for the stranding events can be of interest to researchers in Indonesia and for the local government, but maybe not for the general public unless you support it correctly with scientific literature. 

Other minor concerns are discussed in the attached version of the manuscript.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer 1,

Thank you very much for your time and energy in reviewing our manuscript. We have taken your input into consideration and we think the manuscript is now much improved because of your input.

Sincerely,

Authors

Author Response File: Author Response.docx

Reviewer 2 Report

Despite the results are clearly biassed by the heterogeneous sampling effort along the geographical range, the information gathered by the authors is worth to be published ,as it comprises the historical knowledge on the cetacean strandings in the region and it will be of interest in the future. Besides, the study can be used as an argument to improve the stranding networks in the region. Hence, my comments are mainly focused on making sure that these two aspects are clear in the manuscript.

The authors have clarified hrough  the manuscript the problem caused by the heterogeneous sampling effort, but in my opinion it should be also highlighted in some sections for clarity.

Line 25.- Abstract should be self-contained, avoid the reference to Getis-Ord Gi*, I would just mention Optimized Hot Spot here

Line 28-29.- Please clarify that this could be heavily affected by the limitations of the sampling

Line 55.- The military SONAR linked to the mass strandings of beaked whales is the Mid Frequency Active (MFA) SONAR.

Jepson, P. D. et al. Gas-bubble lesions in stranded cetaceans - Was sonar responsible for a spate of whale deaths after an Atlantic military exercise? Nature 425, 575–576, https://doi.org/10.1038/425575a (2003)

Fernandez, A. et al. “Gas and fat embolic syndrome” involving a mass stranding of beaked whales (Family Ziphiidae) exposed to anthropogenic sonar signals. Veterinary Pathology 42, 446–457 (2005).

Tyack, P. L., Zimmer, W. M. X., Moretti, D., Southall, B. L., Claridge, D. E., Durban, J. W., … Boyd, I. L. (2011). Beaked whales respond to simulated and actual navy sonar. PLoS ONE, 6(3). https://doi.org/10.1371/journal.pone.0017009

Line 215.- Figure 3 needs to be improved with information on data dispersion (SD or Confidence Intervals) in order to be clear for the readers. If the discussion is going to describe diferences between months there should be information on statistical analysis and significance of the mean differences.

Line 218.- To improve readability of figure 2 please highlight the two time periods referred in the text periods at the figure

Figure 5.- need to be improved in the same way than figure 3

Line 258.- Please add statistical analysis information to enhance results this difference can be just a statistical fluctuation and not a real difference.

Figure 5 caption.- Sperm whale is misspelled. The last phrase of the caption should be considered after statistical analysis of the data

Line 295.-  An analysis of the stranding events considering the population density would be also interesting, to see if the results are also biased by how the human population is distributed.

Line 422.- Please consider that the high rate of strandings in a particular region can not only reflect threats but also a high abundance of cetaceans with a normal mortality rate.

Line 435.-  More important than the survivorship of the stranded cetaceans (hard to improve because live strandings of viable cetaceans are very rare events) in to increase the knowledge on the pathologies of the stranded individuals, which will allow to monitor anthropogenic threats and reduce them. Please revise:

Arbelo M, de los Monteros AE, Herra´ez P, Andrada M, Sierra E, Rodrı´guez F, et al. Pathology and causes of death of stranded cetaceans in the Canary Islands (1999–2005). Dis Aquat Organ. 2013; 103 (2): 87–99. https://doi.org/10.3354/dao02558 PMID: 23548359

Díaz-Delgado, J., Fernández, A., Sierra, E., Sacchini, S., Andrada, M., Vela, A. I., … Arbelo, M. (2018). Pathologic findings and causes of death of stranded cetaceans in the Canary Islands (2006-2012). PLoS ONE, 13(10), e0204444. https://doi.org/10.1371/journal.pone.0204444

A proper stranding network with a good pathological research is probably one of the most important tools to improve the conservation of the wild cetacean populations in a region.

Line 429.- I would emphasize the importance of building capacity or establishing a stranding network at least to perform basic necropsies, obtain essential samples and create the capacity to preserve the samples for analysis in central laboratories.

Author Response

Dear Reviewer 2,

Thank you very much for your time and energy in reviewing our manuscript. We have taken your input into consideration and we think the manuscript is now much improved because of your input.

Sincerely,

Authors

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

After the initial revision I think this article have considerably improved. 

However I have some questions about what you say in the lines 224-226 of the revised version: "Survival rate for single stranding events was quite high in Indonesia (~74.8%), but it dropped to only 52.03% for the mass stranding events."

How can you assess the survival rate in an stranding event? 

Do you monitorate the animals after reintroduction? 

Is this high "survival rate" related to stranding assistance? in such case you need to define the assistance protocol in material and methods. 

For me, if animals are not closelly monitored after reintroduction you can not stipulate a survival rate, it is quite possible that the animal died soon after reintroduction and the corpse appears after several days or even weeks. 

Author Response

Apologies for taking this long to reply to this comment. We agree with the reviewer’s assertion. Thus, we have replaced “Survival rate” with “The rate of refloating”. Now, the sentence reads as "The refloating rate for single stranding events was ~74.8% in Indonesia, but it dropped to only 52.03% for the mass stranding events."

We do not feel the need to define “refloating” because that is a common term used during stranding response [1]. This term also does not refer to a warranted success of returning the stranded individuals to sea [2]; it’s just merely describing the activity of returning them to sea. We hope that this revision is sufficient to address Reviewer 1’s comment.

The attached is the revised manuscript after addressing this comment, with track changes. Thank you.

Reference

1. Geraci, J.R.; Lounsbury, V.J. Marine Mammals Ashore: A Field Fuide for Strandings; Texas A&M University Sea Grant College Program: Texas, 1993.
2. Mazzariol, S.; Centelleghe, C.; Cozzi, B.; Povinelli, M.; Marcer, F.; Ferri, N.; Di Francesco, G.; Badagliacca, P.; Profeta, F.; Olivieri, V. Multidisciplinary studies on a sick-leader syndrome-associated mass stranding of sperm whales (Physeter macrocephalus) along the Adriatic coast of Italy. Scientific reports 2018, 8, 1-18.

Author Response File: Author Response.docx

Reviewer 2 Report

All my previous comments have been addressed by changes made by the authors. Congratulations on sharing this important piece of scientific information.

Author Response

Thank you very much for contributing your time, energy, suggestions and passion to this paper, truly appreciate it.

Sincerely,

Authors

Round 3

Reviewer 1 Report

I believe that hits work has substantially improved and can be published.