Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
Horizontal and vertical movements of Caribbean reef sharks
(Carcharhinus perezi): conservation implications of limited
migration in a marine sanctuary
Oliver N. Shipley, Lucy A. Howey, Emily R. Tolentino, Lance K. B. Jordan, Jonathan L. W.
Ruppert and Edward J. Brooks
Article citation details
R. Soc. open sci. 4: 160611.
http://dx.doi.org/10.1098/rsos.160611
Review timeline
Original submission:
1st revised submission:
2nd revised submission:
Final acceptance:
21 August 2016
22 November 2016
17 January 2017
18 January 2017
Note: Reports are unedited and appear as
submitted by the referee. The review history
appears in chronological order.
Review History
RSOS-160611.R0 (Original submission)
Review form: Reviewer 1
Is the manuscript scientifically sound in its present form?
Yes
Are the interpretations and conclusions justified by the results?
Yes
Is the language acceptable?
Yes
Is it clear how to access all supporting data?
Yes.
Do you have any ethical concerns with this paper?
No
© 2017 The Authors. Published by the Royal Society under the terms of the Creative Commons
Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use,
provided the original author and source are credited
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
2
Have you any concerns about statistical analyses in this paper?
No
Recommendation?
Major revision is needed (please make suggestions in comments)
Comments to the Author(s)
Congratulations to the authors. The data you’ve presented are needed to enhance our
understanding of the behavioral ecology of this species, assess its vulnerability to threats such as
pelagic long-line fisheries, and provide an aid to future conservation initiatives. This manuscript
is generally well-constructed and reasonably well-written, but still requires some work to
improve overall readability, clarity, and the interpretation of results. In an attached file, I have
provided some general recommendations as well as detailed line-by-line edits. (Appendix A.)
Review form: Reviewer 2
Is the manuscript scientifically sound in its present form?
Yes
Are the interpretations and conclusions justified by the results?
No
Is the language acceptable?
Yes
Is it clear how to access all supporting data?
I did not see reference to data being available.
Do you have any ethical concerns with this paper?
No
Have you any concerns about statistical analyses in this paper?
No
Recommendation?
Major revision is needed (please make suggestions in comments)
Comments to the Author(s)
In ‘Horizontal and vertical movements of Caribbean reefsharks (Carcharhinus perezi):
Conservation implications of limited migration in a marine sanctuary’ by Oliver N Shipley, Lucy
A. Howey, Emily R. Tolentino, Lance K. B., Jordan, Jonathan L. W. Ruppert and Edward J. Brook,
the authors tag Carribean Reef sharks in the Bahamas and analyze the horizontal and vertical
movements of these animals using satellite tags. The authors find these animals don’t move far
from their tagging locations. Also, they determine 3 broad categories of depth distribution
(behavior) when animals leave the shelf areas.
Though I appreciate the time and effort to collect and analyze these data, the rationale for this
study and novelty seem to have eluded me. The authors conducted some interesting analyses,
however the importance of these data were not clear- especially in light of older studies about C
perezi suggesting limited range and vertical movements and implications for MPAs (i.e.,
Chapman 2007). So I’m not sure why they need to be studied again here in the Bahamas. this
simply seems like a descriptive paper, which was the norm when tagging technology was novel,
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
3
and has already been covered for this species. There's no hypothesis testing etc, which would add
context to this study. Please develop the specific reasoning. Or state that this is the same study
but at a different location, and why that is important or why we would expect it would be
different.
Also, the introduction presents information about EEZs and the Bahamas, but does not justify
why information about vertical or horizontal movements add anything to this discussion or are
necessary here.
I don’t see any major errors in the analysis techniques, the justification and impact of the study
need significant improvement.
Line 3: Remove comma in Lance Jordan’s name on cover page
Line 49: I suggest authors change to ‘greater’
Lines 64-84: I think there is too much background here. The information seems to drag on a bit, I
would suggest cutting this down and streamlining to only the most relevant information.
Lin 84-90: I don’t see the connection to the background in the introduction to the study. Why is
vertical and horizontal movement important to the Bahamas? It’s poorly understood in
Bahamian waters, but a lot is known about their movements in general at other locations. There is
no justification why you can just apply that info here. Why do an entirely new study?
Is this study actually important to the Bahamas or just a descriptive study of their movement
(which has largely been done)?
Line 89: What do animal vertical movements have to do with the efficacy of the EEZ on their
conservation?
Line 214: 71.6km is well within the 200NM EEZ, so why is this important at all in reference to the
reasoning introduction?
Lines 244/252: I am curious why more deep dives occur in the winter, but the average depth is
shallower in the winter? Is that an error or is there an explanation for that?
Line 255: There are typographical errors in this sentence. I don’t understand what this sentence
is saying. Please clarify.
Decision letter (RSOS-160611)
20-Oct-2016
Dear Mr Shipley,
The editors assigned to your paper ("Horizontal and vertical movements of Caribbean reef sharks
(Carcharhinus perezi): Conservation implications of limited migration in a marine sanctuary")
have now received comments from reviewers. We would like you to revise your paper in
accordance with the referee and Subject Editor suggestions which can be found below (not
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
4
including confidential reports to the Editor). Please note this decision does not guarantee
eventual acceptance.
Please submit a copy of your revised paper within three weeks (i.e. by the 12-Nov-2016). If we do
not hear from you within this time then it will be assumed that the paper has been withdrawn. In
exceptional circumstances, extensions may be possible if agreed with the Editorial Office in
advance.We do not allow multiple rounds of revision so we urge you to make every effort to
fully address all of the comments at this stage. If deemed necessary by the Editors, your
manuscript will be sent back to one or more of the original reviewers for assessment. If the
original reviewers are not available we may invite new reviewers.
To revise your manuscript, log into http://mc.manuscriptcentral.com/rsos and enter your
Author Centre, where you will find your manuscript title listed under "Manuscripts with
Decisions." Under "Actions," click on "Create a Revision." Your manuscript number has been
appended to denote a revision. Revise your manuscript and upload a new version through your
Author Centre.
When submitting your revised manuscript, you must respond to the comments made by the
referees and upload a file "Response to Referees" in "Section 6 - File Upload". Please use this to
document how you have responded to the comments, and the adjustments you have made. In
order to expedite the processing of the revised manuscript, please be as specific as possible in
your response.
In addition to addressing all of the reviewers' and editor's comments please also ensure that your
revised manuscript contains the following sections as appropriate before the reference list:
• Ethics statement (if applicable)
If your study uses humans or animals please include details of the ethical approval received,
including the name of the committee that granted approval. For human studies please also detail
whether informed consent was obtained. For field studies on animals please include details of all
permissions, licences and/or approvals granted to carry out the fieldwork.
• Data accessibility
It is a condition of publication that all supporting data are made available either as
supplementary information or preferably in a suitable permanent repository. The data
accessibility section should state where the article's supporting data can be accessed. This section
should also include details, where possible of where to access other relevant research materials
such as statistical tools, protocols, software etc can be accessed. If the data have been deposited in
an external repository this section should list the database, accession number and link to the DOI
for all data from the article that have been made publicly available. Data sets that have been
deposited in an external repository and have a DOI should also be appropriately cited in the
manuscript and included in the reference list.
If you wish to submit your supporting data or code to Dryad (http://datadryad.org/), or modify
your current submission to dryad, please use the following link:
http://datadryad.org/submit?journalID=RSOS&manu=RSOS-160611
• Competing interests
Please declare any financial or non-financial competing interests, or state that you have no
competing interests.
• Authors’ contributions
All submissions, other than those with a single author, must include an Authors’ Contributions
section which individually lists the specific contribution of each author. The list of Authors
should meet all of the following criteria; 1) substantial contributions to conception and design, or
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
5
acquisition of data, or analysis and interpretation of data; 2) drafting the article or revising it
critically for important intellectual content; and 3) final approval of the version to be published.
All contributors who do not meet all of these criteria should be included in the
acknowledgements.
We suggest the following format:
AB carried out the molecular lab work, participated in data analysis, carried out sequence
alignments, participated in the design of the study and drafted the manuscript; CD carried out
the statistical analyses; EF collected field data; GH conceived of the study, designed the study,
coordinated the study and helped draft the manuscript. All authors gave final approval for
publication.
• Acknowledgements
Please acknowledge anyone who contributed to the study but did not meet the authorship
criteria.
• Funding statement
Please list the source of funding for each author.
Once again, thank you for submitting your manuscript to Royal Society Open Science and I look
forward to receiving your revision. If you have any questions at all, please do not hesitate to get
in touch.
Yours sincerely,
Andrew Dunn
Senior Publishing Editor
Royal Society Open Science
on behalf of Kevin Padian
Subject Editor, Royal Society Open Science
[email protected]
Comments to Author:
Reviewers' Comments to Author:
Reviewer: 1
Comments to the Author(s)
Congratulations to the authors. The data you’ve presented are needed to enhance our
understanding of the behavioral ecology of this species, assess its vulnerability to threats such as
pelagic long-line fisheries, and provide an aid to future conservation initiatives. This manuscript
is generally well-constructed and reasonably well-written, but still requires some work to
improve overall readability, clarity, and the interpretation of results. In an attached file, I have
provided some general recommendations as well as detailed line-by-line edits.
Reviewer: 2
Comments to the Author(s)
In ‘Horizontal and vertical movements of Caribbean reefsharks (Carcharhinus perezi):
Conservation implications of limited migration in a marine sanctuary’ by Oliver N Shipley, Lucy
A. Howey, Emily R. Tolentino, Lance K. B., Jordan, Jonathan L. W. Ruppert and Edward J. Brook,
the authors tag Carribean Reef sharks in the Bahamas and analyze the horizontal and vertical
movements of these animals using satellite tags. The authors find these animals don’t move far
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
6
from their tagging locations. Also, they determine 3 broad categories of depth distribution
(behavior) when animals leave the shelf areas.
Though I appreciate the time and effort to collect and analyze these data, the rationale for this
study and novelty seem to have eluded me. The authors conducted some interesting analyses,
however the importance of these data were not clear- especially in light of older studies about C
perezi suggesting limited range and vertical movements and implications for MPAs (i.e.,
Chapman 2007). So I’m not sure why they need to be studied again here in the Bahamas. this
simply seems like a descriptive paper, which was the norm when tagging technology was novel,
and has already been covered for this species. There's no hypothesis testing etc, which would add
context to this study. Please develop the specific reasoning. Or state that this is the same study
but at a different location, and why that is important or why we would expect it would be
different.
Also, the introduction presents information about EEZs and the Bahamas, but does not justify
why information about vertical or horizontal movements add anything to this discussion or are
necessary here.
I don’t see any major errors in the analysis techniques, the justification and impact of the study
need significant improvement.
Line 3: Remove comma in Lance Jordan’s name on cover page
Line 49: I suggest authors change to ‘greater’
Lines 64-84: I think there is too much background here. The information seems to drag on a bit, I
would suggest cutting this down and streamlining to only the most relevant information.
Lin 84-90: I don’t see the connection to the background in the introduction to the study. Why is
vertical and horizontal movement important to the Bahamas? It’s poorly understood in
Bahamian waters, but a lot is known about their movements in general at other locations. There is
no justification why you can just apply that info here. Why do an entirely new study?
Is this study actually important to the Bahamas or just a descriptive study of their movement
(which has largely been done)?
Line 89: What do animal vertical movements have to do with the efficacy of the EEZ on their
conservation?
Line 214: 71.6km is well within the 200NM EEZ, so why is this important at all in reference to the
reasoning introduction?
Lines 244/252: I am curious why more deep dives occur in the winter, but the average depth is
shallower in the winter? Is that an error or is there an explanation for that?
Line 255: There are typographical errors in this sentence. I don’t understand what this sentence
is saying. Please clarify.
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
7
Author's Response to Decision Letter for (RSOS-160611)
See Appendix B.
RSOS-160611.R1 (Revision)
Review form: Reviewer 1
Is the manuscript scientifically sound in its present form?
Yes
Are the interpretations and conclusions justified by the results?
Yes
Is the language acceptable?
Yes
Is it clear how to access all supporting data?
Yes
Do you have any ethical concerns with this paper?
No
Have you any concerns about statistical analyses in this paper?
I do not feel qualified to assess the statistics
Recommendation?
Accept with minor revision (please list in comments)
Comments to the Author(s)
Line 49 – A reference is needed for this statement.
Line 62 – As an official IUCN status, shouldn’t ‘near threatened’ be capitalized?
Lines 75-77 – This statement is about legislation from 2011 that protects sharks in The Bahamas.
But one of the references for this statement [24] is for a 2005 publication. I question whether
either of these two references are appropriate (as opposed to perhaps a footnote for the Bahamian
declaration itself). Please address this.
Line 79 – Banned where since 1993? It is not clear if we’re talking about The Bahamas here. The
two mid-sentence references are about stress. Therefore a reference is needed to support the
statement about longlining being banned since 1993.
Line 216 – When citing a figure, comply with the journal’s format and be consistent (i.e. Figure or
Fig.).
Line 226 – So the light-based tools used (X-Tags) did not provide the geographic resolution
needed to gain insight into the small scale migrations that Caribbean reef sharks are known to be
limited to. Then why was this tool chosen to address the question of movements of reef sharks
with respect to the Bahamian EEZ? We know that light-based methods of fish tracking (i.e.
PSATs) are useful when the animals are making broad ocean scale movements. Rather than
glossing over this in the paper, I think the authors need to clearly discuss the limitations of their
results given the type of tags they chose to use and perhaps allude to alternative approaches that
might provide better results.
Line 205 – Missing comma in 1035.
Line 348 – “importance” should be “important”.
Line 631 – I think there should be a hyphen in ‘steel headed’
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
8
Review form: Reviewer 2
Is the manuscript scientifically sound in its present form?
Yes
Are the interpretations and conclusions justified by the results?
Yes
Is the language acceptable?
Yes
Is it clear how to access all supporting data?
No
Do you have any ethical concerns with this paper?
No
Have you any concerns about statistical analyses in this paper?
No
Recommendation?
Accept with minor revision (please list in comments)
Comments to the Author(s)
I apologize to the authors as only part of my initial comments seemed to have been included in
the first review. The context of my comments were unfortunately absent.
However, the authors addressed the majority of my comments satisfactorily.
My last comment is regarding the use of these data for MPAs. The authors suggest that these
data indicate the MPA is useful for CRS as it protects them in Bahamanian waters 'In conclusion,
the limited movements of Caribbean reef sharks suggests reduced interactions of this subpopulation with extrinsic fishing pressure, possibly sustaining ecological and economic vitality in
The Bahamas.' I would like to see the authors discuss the flip side of this information- that the
MPA in the bahamas therefore will likely not help any other sub-population of CRS outside of the
Bahamas. These data suggest that populations are discrete and a Bahamanian MPA cannot act as
a source for other deleted populations regionally. We often talk about spill-over as being a
benefit of MPAs, but obvious isn't in this case. I'd like to authors to atleast address this in the
discussion.
Decision letter (RSOS-160611.R1)
10-Jan-2017
Dear Mr Shipley:
On behalf of the Editors, I am pleased to inform you that your Manuscript RSOS-160611.R1
entitled "Horizontal and vertical movements of Caribbean reef sharks (Carcharhinus perezi):
Conservation implications of limited migration in a marine sanctuary" has been accepted for
publication in Royal Society Open Science subject to minor revision in accordance with the
referee suggestions. Please find the referees' comments at the end of this email.
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
9
The reviewers and Subject Editor have recommended publication, but also suggest some minor
revisions to your manuscript. Therefore, I invite you to respond to the comments and revise your
manuscript.
• Ethics statement
If your study uses humans or animals please include details of the ethical approval received,
including the name of the committee that granted approval. For human studies please also detail
whether informed consent was obtained. For field studies on animals please include details of all
permissions, licences and/or approvals granted to carry out the fieldwork.
• Data accessibility
It is a condition of publication that all supporting data are made available either as
supplementary information or preferably in a suitable permanent repository. The data
accessibility section should state where the article's supporting data can be accessed. This section
should also include details, where possible of where to access other relevant research materials
such as statistical tools, protocols, software etc can be accessed. If the data has been deposited in
an external repository this section should list the database, accession number and link to the DOI
for all data from the article that has been made publicly available. Data sets that have been
deposited in an external repository and have a DOI should also be appropriately cited in the
manuscript and included in the reference list.
If you wish to submit your supporting data or code to Dryad (http://datadryad.org/), or modify
your current submission to dryad, please use the following link:
http://datadryad.org/submit?journalID=RSOS&manu=RSOS-160611.R1
• Competing interests
Please declare any financial or non-financial competing interests, or state that you have no
competing interests.
• Authors’ contributions
All submissions, other than those with a single author, must include an Authors’ Contributions
section which individually lists the specific contribution of each author. The list of Authors
should meet all of the following criteria; 1) substantial contributions to conception and design, or
acquisition of data, or analysis and interpretation of data; 2) drafting the article or revising it
critically for important intellectual content; and 3) final approval of the version to be published.
All contributors who do not meet all of these criteria should be included in the
acknowledgements.
We suggest the following format:
AB carried out the molecular lab work, participated in data analysis, carried out sequence
alignments, participated in the design of the study and drafted the manuscript; CD carried out
the statistical analyses; EF collected field data; GH conceived of the study, designed the study,
coordinated the study and helped draft the manuscript. All authors gave final approval for
publication.
• Acknowledgements
Please acknowledge anyone who contributed to the study but did not meet the authorship
criteria.
• Funding statement
Please list the source of funding for each author.
Please note that we cannot publish your manuscript without these end statements included. We
have included a screenshot example of the end statements for reference. If you feel that a given
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
10
heading is not relevant to your paper, please nevertheless include the heading and explicitly state
that it is not relevant to your work.
Because the schedule for publication is very tight, it is a condition of publication that you submit
the revised version of your manuscript within 7 days (i.e. by the 19-Jan-2017). If you do not think
you will be able to meet this date please let me know immediately.
To revise your manuscript, log into https://mc.manuscriptcentral.com/rsos and enter your
Author Centre, where you will find your manuscript title listed under "Manuscripts with
Decisions". Under "Actions," click on "Create a Revision." You will be unable to make your
revisions on the originally submitted version of the manuscript. Instead, revise your manuscript
and upload a new version through your Author Centre.
When submitting your revised manuscript, you will be able to respond to the comments made by
the referees and upload a file "Response to Referees" in "Section 6 - File Upload". You can use this
to document any changes you make to the original manuscript. In order to expedite the
processing of the revised manuscript, please be as specific as possible in your response to the
referees.
When uploading your revised files please make sure that you have:
1) A text file of the manuscript (tex, txt, rtf, docx or doc), references, tables (including captions)
and figure captions. Do not upload a PDF as your "Main Document".
2) A separate electronic file of each figure (EPS or print-quality PDF preferred (either format
should be produced directly from original creation package), or original software format)
3) Included a 100 word media summary of your paper when requested at submission. Please
ensure you have entered correct contact details (email, institution and telephone) in your user
account
4) Included the raw data to support the claims made in your paper. You can either include your
data as electronic supplementary material or upload to a repository and include the relevant doi
within your manuscript
5) All supplementary materials accompanying an accepted article will be treated as in their final
form. Note that the Royal Society will neither edit nor typeset supplementary material and it will
be hosted as provided. Please ensure that the supplementary material includes the paper details
where possible (authors, article title, journal name).
Supplementary files will be published alongside the paper on the journal website and posted on
the online figshare repository (https://figshare.com). The heading and legend provided for each
supplementary file during the submission process will be used to create the figshare page, so
please ensure these are accurate and informative so that your files can be found in searches. Files
on figshare will be made available approximately one week before the accompanying article so
that the supplementary material can be attributed a unique DOI.
Once again, thank you for submitting your manuscript to Royal Society Open Science and I look
forward to receiving your revision. If you have any questions at all, please do not hesitate to get
in touch.
Best wishes
Andrew Dunn
Senior Publishing Editor
Royal Society Open Science
[email protected]
on behalf of Kevin Padian
Subject Editor, Royal Society Open Science
[email protected]
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
11
Comments to Author:
Reviewer: 1
Comments to the Author(s)
Line 49 – A reference is needed for this statement.
Line 62 – As an official IUCN status, shouldn’t ‘near threatened’ be capitalized?
Lines 75-77 – This statement is about legislation from 2011 that protects sharks in The Bahamas.
But one of the references for this statement [24] is for a 2005 publication. I question whether
either of these two references are appropriate (as opposed to perhaps a footnote for the Bahamian
declaration itself). Please address this.
Line 79 – Banned where since 1993? It is not clear if we’re talking about The Bahamas here. The
two mid-sentence references are about stress. Therefore a reference is needed to support the
statement about longlining being banned since 1993.
Line 216 – When citing a figure, comply with the journal’s format and be consistent (i.e. Figure or
Fig.).
Line 226 – So the light-based tools used (X-Tags) did not provide the geographic resolution
needed to gain insight into the small scale migrations that Caribbean reef sharks are known to be
limited to. Then why was this tool chosen to address the question of movements of reef sharks
with respect to the Bahamian EEZ? We know that light-based methods of fish tracking (i.e.
PSATs) are useful when the animals are making broad ocean scale movements. Rather than
glossing over this in the paper, I think the authors need to clearly discuss the limitations of their
results given the type of tags they chose to use and perhaps allude to alternative approaches that
might provide better results.
Line 205 – Missing comma in 1035.
Line 348 – “importance” should be “important”.
Line 631 – I think there should be a hyphen in ‘steel headed’
Reviewer: 2
Comments to the Author(s)
I apologize to the authors as only part of my initial comments seemed to have been included in
the first review. The context of my comments were unfortunately absent.
However, the authors addressed the majority of my comments satisfactorily.
My last comment is regarding the use of these data for MPAs. The authors suggest that these
data indicate the MPA is useful for CRS as it protects them in Bahamanian waters 'In conclusion,
the limited movements of Caribbean reef sharks suggests reduced interactions of this subpopulation with extrinsic fishing pressure, possibly sustaining ecological and economic vitality in
The Bahamas.' I would like to see the authors discuss the flip side of this information- that the
MPA in the bahamas therefore will likely not help any other sub-population of CRS outside of the
Bahamas. These data suggest that populations are discrete and a Bahamanian MPA cannot act as
a source for other deleted populations regionally. We often talk about spill-over as being a
benefit of MPAs, but obvious isn't in this case. I'd like to authors to atleast address this in the
discussion.
Author's Response to Decision Letter for (RSOS-160611.R1)
See Appendix C.
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
12
Decision letter (RSOS-160611.R2)
18-Jan-2017
Dear Mr Shipley,
I am pleased to inform you that your manuscript entitled "Horizontal and vertical movements of
Caribbean reef sharks (Carcharhinus perezi): Conservation implications of limited migration in a
marine sanctuary" is now accepted for publication in Royal Society Open Science.
You can expect to receive a proof of your article in the near future. Please contact the editorial
office ([email protected] and [email protected]) to let us know if
you are likely to be away from e-mail contact. Due to rapid publication and an extremely tight
schedule, if comments are not received, your paper may experience a delay in publication.
Royal Society Open Science operates under a continuous publication model
(http://bit.ly/cpFAQ). Your article will be published straight into the next open issue and this
will be the final version of the paper. As such, it can be cited immediately by other researchers.
As the issue version of your paper will be the only version to be published I would advise you to
check your proofs thoroughly as changes cannot be made once the paper is published.
In order to raise the profile of your paper once it is published, we can send through a PDF of your
paper to selected colleagues. If you wish to take advantage of this, please reply to this email with
the name and email addresses of up to 10 people who you feel would wish to read your article.
On behalf of the Editors of Royal Society Open Science, we look forward to your continued
contributions to the Journal.
Best wishes,
Alice Power
Editorial Coordinator
Royal Society Open Science
[email protected]
from http://rsos.royalsocietypublishing.org/ on June 17, 2017
AppendixDownloaded
A
Review of Manuscript ID RSOS-160611
"Horizontal and vertical movements of Caribbean reef sharks (Carcharhinus perezi):
Conservation implications of limited migration in a marine sanctuary."
Comments to Authors:
Congratulations to the authors. The data you’ve presented are needed to enhance our
understanding of the behavioral ecology of this species, assess its vulnerability to threats such
as pelagic long-line fisheries, and provide an aid to future conservation initiatives. This
manuscript is generally well-constructed and reasonably well-written, but still requires some
work to improve overall readability, clarity, and the interpretation of results. In an attached file, I
have provided some general recommendations as well as detailed line-by-line edits.
General Recommendations:
- In a few instances, there are long run-on sentences. For better clarity, try to economize on
words and if necessary, divide into two sentences (examples are noted under Specific
Recommendations).
- I think it would be simpler and clearer to identify each shark/tag by using a series of sequential
numbers (e.g. Shark 1, Shark 2 etc.) rather than utilizing the 5 or 6 digit Agros PTT number.
This is just a suggestion.
- A significant part of the paper’s main conclusions are related to foraging. But in my opinion,
the authors have done an inadequate job of digging into the literature to better establish the diet
of this shark species in order to support their hypotheses. Without this support, I feel their
conclusions are too speculative.
- When attempting to interpret their results, I would like to see the authors explore (and offer)
some alternative explanations.
- The table and figure headings are generally not descriptive enough. They should be able to
stand alone and provide enough for the reader to understand the main idea of the figure/table.
For example, none of the headings tell the reader what species we’re dealing with.
Specific Recommendations:
Abstract
Line 32 – Should make it clear that you’re talking about depth here. Perhaps modify with “down
to a depth of 436.1 m”.
Introduction
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
Line 40 – Specify what measurement this is (e.g. TL).
Line 44 – Insert space after 200.
Lines 46-48 – Does the prevalence of Caribbean reef sharks really “mean” this? Please clarify
and/or back this up with a reference.
Lines 56-60 – This is a very long run-on sentence that needs to be modified for clarity.
Line 61 – Should be “the Caribbean reef shark”.
Line 66 – Multi reference citations are not punctuated consistently. Line 46 uses commas
between them. This line does not.
Line 75 – Use the EEZ abbreviation.
Line 79 – End sentence with “regions”. Start new sentence with “For example, …”
Line 80 – Rather than “one”, should this not say “an order of” in reference to magnitude?
Lines 87-90 – Please economize on words here or divide this into two sentences.
Methods
Line 112 – Add the word “first” if referring to the first dorsal fin. I further ask that further detail be
added on how the hole was made in that fin in order to pass the monofilament bridle through.
Line 172 – The word “familywise” should be “family-wise”.
Results
Lines 204-206 – This seems like interpretation of the data and therefore should be in the
Discussion.
Line 214 – This is not worded clearly as you’re talking about multiple tags/positions. I would
suggest, “The initial Argos-estimated positions…”
Lines 217/221 – There seems to be inconsistencies with how numbers are written. Numbers
less than 10 are spelled out here. But in other cases they are written as numbers (e.g. Line
122).
Line 219-220 – This is indicating that wind would be the prevailing factor in the movement of
detached tags. But wouldn’t the drift of these small, relatively low-profile tags not be more
prone to the effects of prevailing water currents?
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
Line 255 – Inconsistent use of commas for thousands separator. No commas used in other 4
digit numbers (e.g. Line 96). But were used for 6 digit numbers (e.g. Line 207).
Line 261 – The dive itself is not “V-shaped”. Rather it’s the time-depth profile of the dive.
Please clarify.
Lines 291-294 – The word “suggest” comes up twice in this sentence. As the reader, I don’t
sense/gain a lot of confidence in what is being reported here. Caution should be taken in
drawing too far a conclusion from this unpublished genetic study. Also, this Ph.D. Dissertation
is from 2014 and not 2013 (according to the NSU website).
Line 303 – Perhaps replace “indicate and drive” with something like “identify and facilitate”.
Line 315 – Rather than “presents”, probably intended “represents”.
Line 320 – The word “Annually” is not appropriate here. Perhaps “seasonally” would be better.
Line 323/324 – This statement should be supported with more or better references. This lone
tiger shark reference isn’t enough. Is there nothing available for C. perezi to support this? If
not, then perhaps provide some evidence that other more comparable reef shark species exhibit
this behavior.
Line 325/326 – You’re hypothesizing that the vertical excursions of C. perezi are to exploit
vertically migrating prey. But you haven’t established anything about the diet of this shark
species at this point. Citing this squid reference [60] is only meaningful if you have some
evidence that Caribbean reef sharks actually feed on squid. Otherwise its total speculation and
does not belong in the paper.
Lines 329-331 – This is not the only possible explanation for these observations….especially
given the relatively low sample size and short duration of many tracks. Alternative explanations
should be explored and offered in the Discussion.
Line 335 – Replace “indicating” with “indicate”.
Line 343 – Space needed after 100.
Line 344 – A reference to the diet of C. perezi is provided here. But it would be useful to know if
the cephalopods reported were squid (as per comments from Lines 325/326). Also see Tavares
(2009) for more diet info for this species.
Lines 347/348 – The genus Carcharhinus has appeared earlier…hence these sci. names can
be abbreviated to C. amblyrhynchos and C. melanopterus.
Line 356 – Instead of always referring to the species as the ‘Caribbean reef shark’, I would
suggest occasionally substituting it with C. perezi to avoid repetition.
Lines 357-359 – One of the main conclusions of your paper hinges on foraging behavior, but
you have not dug deep enough into what is known about the diet of C. perezi to draw these
conclusions.
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
References
General – Many references do not end with periods. And the formatting has a number of
inconsistencies. For example, spaces follow author initials in most references, but not in all.
Line 372 – Italicize the sci. name.
Lines 388-390 – Some formatting of indents required in this reference (and others).
Line 418 - Line needs indent.
Lines 445/448 – The journal abbreviations incorporate periods (between words) in most cases
but not consistently.
Line 459 – Punctuation immediately following journal title is not consistent either. No comma
here but a comma is used in other examples.
Line 494 – Capitalize the publication’s title.
Line 502 – Journal issue number should be bold for consistency.
Line 518 – Please double-check this reference. The Nova Southeastern University website
shows this Doctorate thesis to be from 2014.
Line 524 – This reference lists 6 authors then abbreviates the remaining with “et al.” Reference
26 lists 10 authors with no “et al.” Should be consistent and/or follow the journal’s guidelines.
Line 534 – Journal name is not abbreviated.
Other sections
Lines 559/562 – Should be X-Tags (with capital T)
Lines 576/577 – Table 1 heading needs a period. There is a vertical line in the left margin that
may be a holdover from tracked changes that were not accepted.
Line 582. Table 2 heading needs to be more explanatory.
Line 614. Table 5 heading is similarly not very informative.
Lines 621 and 623 – Abbreviations (e.g. HR and SR) are not normally used in figure captions.
Figures
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
Fig. 1 – In the caption, should specify “first” dorsal fin. And for clarity, could also mention that
yellow conventional tags can be seen in the photo.
Fig. 2. I do not find this a very effective figure in its present form. The caption indicates that all
start and end points are connected by a line. But it’s just the 7-day drift tags that have this line. I
would suggest a more zoomed-in version that has the start and end points for individual sharks
connected. A scale bar in km is also needed.
Fig. 3. The caption should be more explanatory. The x-axis should be labelled (Date).
Appendix B
Manuscript ID RSOS-160611 – Shipley et al. Horizontal and vertical habitat use of
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
the Caribbean reef shark (Carcharhinus perezi): Conservation implications of
limited migration in a marine sanctuary.
Response to reviewers
Reviewer 1
Comments to Authors:
Congratulations to the authors. The data you’ve presented are needed to enhance our
understanding of the behavioral ecology of this species, assess its vulnerability to
threats such as pelagic long-line fisheries, and provide an aid to future conservation
initiatives. This manuscript is generally well-constructed and reasonably well-written,
but still requires some work to improve overall readability, clarity, and the
interpretation of results. In an attached file, I have provided some general
recommendations as well as detailed line-by-line edits.
General Recommendations:
In a few instances, there are long run-on sentences. For better clarity, try to
economize on words and if necessary, divide into two sentences (examples are noted
under Specific Recommendations).
We have improved the clarity of expression outlined in the specific recommendations.
- I think it would be simpler and clearer to identify each shark/tag by using a
series of sequential numbers (e.g. Shark 1, Shark 2 etc.) rather than utilizing
the 5 or 6 digit Agros PTT number.
We find it clearer for the authors to refer to each shark by the PSAT ID. This has been
the convention in many other articles citied in this paper. Additionally, this
convention allows for consistency across studies if these individual datasets are
incorporated into other future studies and publications.
This is just a suggestion.
A significant part of the paper’s main conclusions are related to foraging. But in my
opinion, the authors have done an inadequate job of digging into the literature to
better establish the diet of this shark species in order to support their hypotheses.
Without this support, I feel their conclusions are too speculative.
We provide further evidence from Motta et al. (1999) and Tavares et al. (2009)
suggesting this species has a broad diet range which encompasses prey items found on
neritic and mesophotic reefs, as well as deeper mesopelagic/bathyal habitats.
However, there is little diet information for Caribbean reef sharks in this specific
study locale.
When attempting to interpret their results, I would like to see the authors explore (and
offer) some alternative explanations.
We cite alternative explanations for these behaviors; however there is a significant
amount of evidence illustrating the use of deeper habitats as prey pools for coastal
requiem sharks. We therefore discuss this in much greater detail as we believe it to be
the most plausible explanation for this behavior. In addition, there is little evidence to
suggest Downloaded
the vertical
movements
of Caribbean reefonsharks
are
associated with any other
from
http://rsos.royalsocietypublishing.org/
June 17,
2017
possible hypotheses, in-part due to the lack of life-history data on this species.
-The table and figure headings are generally not descriptive enough. They should be
able to stand alone and provide enough for the reader to understand the main idea of
the figure/table. For example, none of the headings tell the reader what species we’re
dealing with.
We have added the name of this species to every table and figure caption as well as
provided more details in figure and table legends.
Specific Recommendations:
Abstract
Line 32 – Should make it clear that you’re talking about depth here. Perhaps modify
with “down to a depth of 436.1 m”.
Changed and now reads ‘down to a depth of 436.1 m’
Introduction
Line 40 – Specify what measurement this is (e.g. TL).
Changed to ‘maximum total length 295 cm’
Line 44 – Insert space after 200.
Changed
Lines 46-48 – Does the prevalence of Caribbean reef sharks really “mean” this?
Please clarify and/or back this up with a reference.
We have changed the sentence structure and removed confusing term; it now reads
‘Caribbean reef sharks are considered one of the major top-predators on coral reefs
throughout the Caribbean, and are pivotal to the health, and subsequent resources
provided by these ecosystems
Lines 56-60 – This is a very long run-on sentence that needs to be modified for
clarity.
We have split this into two sentences and improved clarify of expression. The
sentences now read as follows ‘Although Caribbean reef sharks show high relative
abundance compared to other predators across their range [10], artisanal [11]
and commercial fishing [12] as well as coastal development [11] [13] threaten
their populations. This is likely exacerbated by their tendency to move across
relatively large spatial scales through a multitude of ecosystems including
coastal reefs, open-ocean and deep-water habitats (> 200 m) [4].’
Line 61 – Should be “the Caribbean reef shark”.
Changed
Line 66 – Multi reference citations are not punctuated consistently. Line 46 uses
commas between them. This line does not.
We have removed all commas between multi reference citations throughout the
manuscript for consistency.
Line 75 – Use the EEZ abbreviation.
This does not follow proper grammar, on its first use; the full term should be used
prior to abbreviation. We therefore have not changed this.
Line 79 – End sentence with “regions”. Start new sentence with “For example, …”
Changed.
Line 80 – Rather than “one”, should this not say “an order of” in reference to
magnitude?
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
Changed
Lines 87-90 – Please economize on words here or divide this into two sentences.
We have removed words, this sentence now reads ‘Therefore, we used pop-up
satellite archival tags (PSATs), which have proven valuable in assessing shark
movements [29] [30] [31] [21], to examine horizontal and vertical movements
exhibited by Caribbean reef sharks in The Bahamas.’
Methods
Line 112 – Add the word “first” if referring to the first dorsal fin. I further ask that
further detail be added on how the hole was made in that fin in order to pass the
monofilament bridle through.
We have added this section, which reads ‘A small pilot hole was made through the
leading edge of the dorsal fin using a sterile, stainless steel scalpel prior to tag
attachment.’
Line 172 – The word “familywise” should be “family-wise”.
Changed.
Results
Lines 204-206 – This seems like interpretation of the data and therefore should be in
the Discussion.
We have removed this sentence from the results.
Line 214 – This is not worded clearly as you’re talking about multiple tags/positions.
I would suggest, “The initial Argos-estimated positions…”
Changed.
Lines 217/221 – There seems to be inconsistencies with how numbers are written.
Numbers less than 10 are spelled out here. But in other cases they are written as
numbers (e.g. Line122).
Numbers of ten and below, which do not have specific units, are written as words, all
others are now numbers. This is consistent throughout the manuscript.
Line 219-220 – This is indicating that wind would be the prevailing factor in the
movement of detached tags. But wouldn’t the drift of these small, relatively low
profile tags not be more prone to the effects of prevailing water currents?
We have changed the terminology so this now reads ‘up-current’.
Line 255 – Inconsistent use of commas for thousands separator. No commas used in
other 4 digit numbers (e.g. Line 96). But were used for 6 digit numbers (e.g. Line
207).
All four-digit numbers now have consistent use of commas throughout.
Line 261 – The dive itself is not “V-shaped”. Rather it’s the time-depth profile of the
dive.
Please clarify.
We have changed expression and improved clarity, this now reads ‘Dive switch count
ranged from 1 to 55 among dive events, however, the majority of excursions (77.2%)
only contained
onefrom
change
in direction (switch count
= 1),
such that the time-depth
Downloaded
http://rsos.royalsocietypublishing.org/
on June
17, 2017
profile appeared as a ‘V-shaped’ dive.
Lines 291-294 – The word “suggest” comes up twice in this sentence. As the reader, I
don’t sense/gain a lot of confidence in what is being reported here. Caution should be
taken in drawing too far a conclusion from this unpublished genetic study. Also, this
Ph.D. Dissertation is from 2014 and not 2013 (according to the NSU website).
We have removed this sentence and reference from our manuscript.
Line 303 – Perhaps replace “indicate and drive” with something like “identify and
facilitate”.
Changed to ‘identify and facilitate’.
Line 315 – Rather than “presents”, probably intended “represents”.
Changed presents to ‘indicates’ as to avoid the double-use of ‘represents’ in this
sentence.
Line 320 – The word “Annually” is not appropriate here. Perhaps “seasonally” would
be better.
Changed to ‘seasonally’.
Line 323/324 – This statement should be supported with more or better references.
This lone tiger shark reference isn’t enough. Is there nothing available for C. perezi to
support this? If not, then perhaps provide some evidence that other more comparable
reef shark species exhibit this behavior.
We have replaced this reference with a new review paper by Hammerschlag et al. (In
Press), which focuses specifically on the nocturnal behaviours of elasmobranchs,
including foraging.
Line 325/326 – You’re hypothesizing that the vertical excursions of C. perezi are to
exploit vertically migrating prey. But you haven’t established anything about the diet
of this shark species at this point. Citing this squid reference [60] is only meaningful
if you have some evidence that Caribbean reef sharks actually feed on squid.
Otherwise its total speculation and does not belong in the paper.
We now mention the broad diet of this species. We also propose foraging on
mesophotic reefs and draw on work from similar taxa to support this statement (e.g.
Papastamatiou et al. 2014). We keep the potential prey items broad, as we agree that
we cannot determine the specific species, on which Caribbean reef sharks are foraging
in this study.
Lines 329-331 – This is not the only possible explanation for these
observations….especially given the relatively low sample size and short duration of
many tracks. Alternative explanations should be explored and offered in the
discussion
We feel there is significant evidence across the literature to suggest these directed
movements pertain largely to foraging. However, we have added other potential
solutions for this behavior (lines 329 – 333). Studies on the movement and dietary
composition of other reef sharks (McCauley et al., 2012; Papastamatiou et al., 2014)
show a significant contribution of epi- and mesopelagic prey items to the diets of
coastal requiem sharks (Carcharhinus spp.). Therefore, we feel this is the most
plausible explanation for such deep excursions during the night time. The reviewer
states ‘short
duration
of many tracks’; however we
a number
of longer term
Downloaded
from http://rsos.royalsocietypublishing.org/
on have
June 17,
2017
tracks (>30 days) so that we were able to make inferences as to why foraging
strategies (depth use) may change by season – i.e. deepening of the mixed layer.
Line 335 – Replace “indicating” with “indicate”.
Changed
Line 343 – Space needed after 100.
Changed
Line 344 – A reference to the diet of C. perezi is provided here. But it would be useful
to know if the cephalopods reported were squid (as per comments from Lines
325/326). We are unsure whether the cephalopods reported were in-fact squid.
Therefore, we suggest movements may pertain to foraging on mesophotic reefs as
well as diel-vertically migrating prey items.
Also see Tavares (2009) for more diet info for this species.
We have used this reference to illustrate foraging on mesophotic coral reefs.
Lines 347/348 – The genus Carcharhinus has appeared earlier…hence these sci.
names can be abbreviated to C. amblyrhynchos and C. melanopterus.
Changed.
Line 356 – Instead of always referring to the species as the ‘Caribbean reef shark’, I
would suggest occasionally substituting it with C. perezi to avoid repetition.
We don’t agree with switching between the two, as this may confuse the reader; we
therefore keep the consistent use of ‘Caribbean reef shark’.
Lines 357-359 – One of the main conclusions of your paper hinges on foraging
behavior, but you have not dug deep enough into what is known about the diet of C.
perezi to draw these conclusions.
We do not stress that movements are solely associated with foraging. Our conclusions
are short and concise and simply mention that movements may correspond to
foraging on deeper prey pools. We draw conclusions from studies relating to similar
taxa (e.g. Papistamatiou et al. 2014) suggesting coastal requiem sharks feed on deeper
mesophotic reefs, as well as deeper mesopelagic/bathypelagic prey items during the
night. The broad diet-type of this species, as referenced in the discussion, suggests
that cephalopods and other pelagic fishes, known to perform diel-vertical movements
could serve as important prey for these species. We do not discount other potential
hypotheses (lines 239 – 333) however due to the ambiguity and lack of evidence
(especially within Carcharhinids) associated with these hypotheses, they are not
discussed further.
References
General – Many references do not end with periods. And the formatting has a number
of inconsistencies. For example, spaces follow author initials in most references, but
not in all.
Line 372 – Italicize the sci. name.
Changed.
Lines 388-390 – Some formatting of indents required in this reference (and others).
Changed.
Downloaded from http://rsos.royalsocietypublishing.org/ on June 17, 2017
Line 418 - Line needs indent.
Changed.
Lines 445/448 – The journal abbreviations incorporate periods (between words) in
most cases but not consistently.
Changed.
Line 459 – Punctuation immediately following journal title is not consistent either. No
comma here but a comma is used in other examples.
Changed periods now only follow an abbreviation.
Line 494 – Capitalize the publication’s title.
Changed.
Line 502 – Journal issue number should be bold for consistency.
Changed.
Line 518 – Please double-check this reference. The Nova Southeastern University
website shows this Doctorate thesis to be from 2014.
Changed to 2014.
Line 524 – This reference lists 6 authors then abbreviates the remaining with “et al.”
Corrected in line with journal guidelines.
References 26 lists 10 authors with no “et al.” Should be consistent and/or follow the
journal’s guidelines.
Corrected
Line 534 – Journal name is not abbreviated.
Corrected
Other sections
Lines 559/562 – Should be X-Tags (with capital T)
Corrected.
Lines 576/577 – Table 1 heading needs a period. There is a vertical line in the left
margin that may be a holdover from tracked changes that were not accepted.
Corrected.
Line 582. Table 2 heading needs to be more explanatory.
This has been corrected.
Line 614. Table 5 heading is similarly not very informative.
This heading has been extended.
Lines 621 and 623 – Abbreviations (e.g. HR and SR) are not normally used in figure
captions.
Changed to full with abbreviation in parentheses.
Figures
Fig. 1 – Downloaded
In the caption,
should specify “first” dorsal
fin. 17,
And
for clarity, could also
from http://rsos.royalsocietypublishing.org/
on June
2017
mention that yellow conventional tags can be seen in the photo.
Changed and now reads ‘X-Tag attachment through the leading (anterior) edge of the
first dorsal fin. Conventional, yellow steel headed dart tag is also visible’.
Fig. 2. I do not find this a very effective figure in its present form. The caption
indicates that all start and end points are connected by a line. But it’s just the 7-day
drift tags that have this line. I would suggest a more zoomed-in version that has the
start and end points for individual sharks connected. A scale bar in km is also needed.
The figure legend has been clarified and a distance scale bar has been added.
However, we wanted the figure to be zoomed-out enough to display the surrounding
study area, particularly, since the horizontal tracks of the sharks could not be
resolved. Further, all start and end point pairs are actually connected with a straight
line; however, most of the tags reported close to the tagging sites so that the straight
lines could not be resolved (this is now noted in the figure legend). The displacement
lines are only noticeable in the cases such that the tag drifted for seven days.
Consequently, this figure illustrates the lack of confirmed net movement in all tracked
sharks.
Fig. 3. The caption should be more explanatory. The x-axis should be labeled (Date).
This caption has been extended to better describe the figure.
Reviewer 2
Line 3: Remove comma in Lance Jordan’s name on cover page
Change.
Line 49: I suggest authors change to ‘greater’
Now reads ‘greater Caribbean’.
Lines 64-84: I think there is too much background here. The information seems to
drag on a bit, I would suggest cutting this down and streamlining to only the most
relevant information.
In a study that is focusing on a single species, we feel it pertinent to provide a
thorough background as to why this study is necessary, as well as a brief history on
the conservation status of the study species. We therefore feel this paragraph provides
important background as to why the study of Caribbean reef sharks is necessary.
Lin 84-90: I don’t see the connection to the background in the introduction to the
study. Why is vertical and horizontal movement important to the Bahamas? It’s
poorly understood in Bahamian waters, but a lot is known about their movements in
general at other locations. There is no justification why you can just apply that info
here. Why do an entirely new study?
We do not understand this statement. Firstly, we stress the importance of quantifying
horizontal movements with regards to the efficacy of the Bahamian MPA in
protecting highly mobile shark populations. In text examples include the statement
‘The Bahamas, therefore, offers a unique opportunity to quantify the movements and
interactions of an apex predatory shark which reside fully, or for part of its life-
history, within a single marine management zone [21] [22]’.
Secondly,
we disagree
that ‘a lot’ is known about on
the
movements
of this species in
Downloaded
from http://rsos.royalsocietypublishing.org/
June
17, 2017
general. The reviewer is supposedly basing this point on the small collection of
tracking studies (primarily acoustic), which have extremely limited spatial limitations.
For example, the Chapman et al. (2007) study, used PSAT’s to study the long-term
movements of this species on Glovers reef atoll, Belize, and is currently the only
study to track this species over larger spatial scales. However, this study was
conducted on an isolated atoll, with tracking periods between 7 and 20 days.
Therefore, the suggestion that we could simply apply this tracking data to species that
reside at a completely different locale, with a different mosaic of habitats, could be
erroneous. In addition, Chapman et al. (2007) did not provide any long-term tracking
data for this species, again stressing the novelty and importance of the data presented
in this manuscript (tracking days ranging from 30–243 days).
Is this study actually important to the Bahamas or just a descriptive study of their
movement (which has largely been done)?
We disagree with the reviewer that a study describing Caribbean reef shark movement
has ‘largely been done’, and we find this comment surprising if the reviewer is
familiar with Chapman, Pikitch and Brooks et al. papers. Movement data for this
species is limited, especially within the greater Caribbean. We stress in multiple
sections of the introduction and discussion that Caribbean reef sharks constitute the
most commonly seen shark on tourism dives and therefore are responsible for
significant economic income to the Bahamas. The tagged sub-population of
Caribbean reef sharks did not move beyond the Bahamian EEZ suggesting that their
populations are likely to be sustained, which, in turn, sustains dive tourism operations.
We make this point clear in the discussion and in the introduction with the statement
‘In addition to their ecological role as top predators, common sightings on
recreational shark dives, especially within the great Caribbean, creates a significant
economic reliance upon healthy Caribbean reef shark populations [8].’
Line 89: What do animal vertical movements have to do with the efficacy of the EEZ
on their conservation?
Assessing the vertical movements of animals increases our knowledge as to their
ecological role as vectors of ecosystem connectivity between multiple ecosystems.
This again, stresses the need to maintain their populations, and thus quantify whether
they remain ‘protected’ during their life-history.
Line 214: 71.6km is well within the 200NM EEZ, so why is this important at all in
reference to the reasoning introduction?
This point confuses us. We are suggesting that Caribbean reef sharks, large mobile
predators, who have the potential to perform longer migrations outside of the
Bahamas EEZ, stay relatively resident. This is therefore important to their
conservation as they remain ‘protected’ throughout the year. Furthermore, the longest
prior track reported by Chapman et al. 2007 provided little information on long-term
movements.
Lines 244/252: I am curious why more deep dives occur in the winter, but the
average depth is shallower in the winter? Is that an error or is there an explanation for
that?
The depth of the mixed layer is deeper during winter, which could result in increased
food-pulses
to depths
of diving. On average thermoregulation
Downloaded
from http://rsos.royalsocietypublishing.org/
on June 17, 2017likely results in the
shallower depth preference during this time. However, as the text states, a larger
sample size is required to further assess these seasonal affects.
Line 255: There are typographical errors in this sentence. I don’t understand what
this sentence is saying. Please clarify.
We have removed errors and provided clarity; this sentence now reads ‘Individuals
with high-resolution datasets (n = 7) demonstrated 2,118 excursions below 50 m
indicating use of deeper habitats adjacent to the Great Bahamas Bank (Table 4).’
Appendix C
Comments to Author:
Reviewer:
1
Downloaded
from http://rsos.royalsocietypublishing.org/ on June 17, 2017
Comments to the Author(s)
Line 49 – A reference is needed for this statement.
We have cited the papers of Chapman et al. (2007) and Brooks et al. (2013) which
cover this topic well across the Caribbean.
Line 62 – As an official IUCN status, shouldn’t ‘near threatened’ be capitalized?
We have changed this to ‘Near Threatened’.
Lines 75-77 – This statement is about legislation from 2011 that protects sharks in
The Bahamas. But one of the references for this statement [24] is for a 2005
publication. I question whether either of these two references are appropriate (as
opposed to perhaps a footnote for the Bahamian declaration itself). Please address
this.
We disagree removing the citation of Howey-Jordan et al. (2013). This paper clearly
explains the implications of the Bahamian shark sanctuary for mobile oceanic
whitetip sharks. This paradigm is directly related to the point we are outlining here.
We add an additional reference by Hoyte (2014), which is a book chapter making
several references to the Bahamian shark sanctuary, and its associated benefits. We
have removed the 2005 reference.
Line 79 – Banned where since 1993? It is not clear if we’re talking about The
Bahamas here. The two mid-sentence references are about stress. Therefore a
reference is needed to support the statement about longlining being banned since
1993.
We have reworded this sentence, and aligned with the Howey et al. (2013) reference,
which states that longlining is banned in the Bahamas.
Line 216 – When citing a figure, comply with the journal’s format and be consistent
(i.e. Figure or Fig.).
All figures are now referred to as ‘Figure’ in-text.
Line 226 – So the light-based tools used (X-Tags) did not provide the geographic
resolution needed to gain insight into the small scale migrations that Caribbean reef
sharks are known to be limited to. Then why was this tool chosen to address the
question of movements of reef sharks with respect to the Bahamian EEZ? We know
that light-based methods of fish tracking (i.e. PSATs) are useful when the animals are
making broad ocean scale movements. Rather than glossing over this in the paper, I
think the authors need to clearly discuss the limitations of their results given the type
of tags they chose to use and perhaps allude to alternative approaches that might
provide better results.
As satellite-tracking data for Caribbean reef sharks is extremely limited, we did not
know whether individuals would make more extensive migrations than observed at
other locales. Therefore PSAT’s were an informed approach to test this hypothesis.
Caribbean reef sharks are commonly spotted off the coast of Florida, and it is well
within the bounds of possibility that individuals could have followed similar
movements
to thatfrom
of http://rsos.royalsocietypublishing.org/
bull, tiger, and hammerheadonsharks
Downloaded
June 17,(See
2017 Graham et al., 2016).
We state that our observations remain inconclusive, and draw on prior knowledge e.g.
reproduction to offer possible solutions to why animals may move away from
Eleuthera. We have added a sentence indicating how alternative approaches can be
used to better inform finer-scale movements, in relation to specific locations with
associated citations: ‘Although light-based geolocation estimates proved somewhat
limited in their ability to discern finer-scale movements, in relation to the EEZ
boundary, this could be achieved in future studies through the use of passive
telemetry, or chemical tracer approaches such as stable isotope analysis.’
However, we do not feel it necessary to rigorously draw on limitations of geolocation,
as we do not go into detail, nor make extensive claims regarding the specific
horizontal movement of individual sharks.
Line 205 – Missing comma in 1035.
Changed.
Line 348 – “importance” should be “important”.
Changed.
Line 631 – I think there should be a hyphen in ‘steel headed’
Changed.
Reviewer: 2
Comments to the Author(s)
I apologize to the authors as only part of my initial comments seemed to have been
included in the first review. The context of my comments were unfortunately absent.
However, the authors addressed the majority of my comments satisfactorily.
My last comment is regarding the use of these data for MPAs. The authors suggest
that these data indicate the MPA is useful for CRS as it protects them in Bahamanian
waters 'In conclusion, the limited movements of Caribbean reef sharks suggests
reduced interactions of this sub-population with extrinsic fishing pressure, possibly
sustaining ecological and economic vitality in The Bahamas.' I would like to see the
authors discuss the flip side of this information- that the MPA in the bahamas
therefore will likely not help any other sub-population of CRS outside of the
Bahamas. These data suggest that populations are discrete and a Bahamanian MPA
cannot act as a source for other deleted populations regionally. We often talk about
spill-over as being a benefit of MPAs, but obvious isn't in this case. I'd like to authors
to atleast address this in the discussion.
We are not sure the reviewer has fully read through our discussion. We feel
this comment is addressed in lines 295 – 301, which reads: ‘However, the relatively
localised movements, if uniform across sub-populations, may have greater
implications for individuals in unprotected regions. For example, the bottom longline
fisheries of Columbia target Caribbean reef sharks for their skin, oil, and fins [2] and
may be contributing to significant population declines within unprotected subpopulations. Although this was beyond the scope of this study, assessing Caribbean
reef shark movements across multiple locations will help identify and facilitate more
appropriate
management
strategies within and between
Downloaded
from http://rsos.royalsocietypublishing.org/
on June nations.’
17, 2017