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Abstracts

Abstracts must be submitted on-line at this website. Registered delegates can submit a maximum of two abstracts as the first author. All abstracts must be in English.


 

Abstract submission deadline: February 28, 2018

Authors notification deadline: The Organizing Committee will notify authors whether abstracts have been selected or not and their presentation modality (oral or poster) by April 15th, 2018.


 

FORM AND PREPARATION OF ABSTRACTS:

Text must be in Word for Windows (docx). Use 12 point Times New Roman font, 1.0 spacing and fully justified text. Generic and specific taxon names and Latin terms should be italics. Do not cite references, unless needed (in that case use only the author’s name). Figures and Tables are not allowed in the Abstract. Please refer to the given abstract model. If you have any questions or problems in abstract preparation or submission please contact us at contact@sharksinternational.org.br.


 

Abstracts must contain the following items, in the cited order:


 

Title. Title in lower case and bold. Title must not exceed 30 words or 180 characters;

Author(s) name(s). Use only initials in uppercase and first author’s name in bold. Never abbreviate first names. Use commas to separate names of multiple authors and sequential superscript numerals to indicate authors’ affiliations and addresses;

Address. Indicate authors’ affiliations and addresses. Include e-mail address of at least the first author;

Abstract. The Abstract must be in running text (no paragraphs) and show the essential qualities of the presentation, including an objective statement on the obtained results. Text must be 200 to 400 words, excluding other items. Text and findings should not have been published elsewhere;

Key words. Include at least one and no more than five key words or expressions; do not repeat title words or expressions;

Financial support. Acknowledge financial support (if needed).


 

ABSTRACT MODEL

 

How many are there? An integrated approach for estimating the size of the white shark population in South Africa

 

Sara Andreotti1, Michael Rutzen2, Sophie von der Heyden1, Michael Meÿer3, Herman Oosthuizen3 and Conrad A Matthee1

 

1Evolutionary Genomics group, Department of Botany and Zoology, Private bag x1, Stellenbosch University, Stellenbosch 7600, South Africa. Email: andreottisara@gmail.com.

2Shark Diving Unlimited, Kleinbaai, Gansbaai, 7220, South Africa

3Department of Environmental Affairs, Branch Oceans and Coasts, Private bag x2, Roggebaai 8012, South Africa


 

White sharks (Carcharodon carcharias) are a vulnerable species with a wide geographic distribution globally. The elusive nature of this predator makes its monitoring, and thus conservation, extremely challenging, particularly when attempting to estimate population abundance. In this study we propose an integrated approach combining, for the first time, genetic as well as mark-recapture (photo identification-based) techniques on free ranging sharks, in order to assess population estimates on both regional and national scales in South Africa. Two-hundred and seventy one biopsy samples were collected (between 2010 and 2013) from 219 white sharks in five sampling locations with known shark aggregations. The analyses of eight polymorphic microsatellite markers for C. carcharias reveals a contemporary effective population size (CNe) of 580 individuals (95% confidence, Pcrit = 0.01) for the South African coastline and CNe of 490 individuals when only analyzing Gansbaai (95% confidence, Pcrit = 0.02). Additionally, between 2009 and 2011, 4389 dorsal fin photo identifications in the vicinity of Gansbaai were collected, from which we could confidently identify 426 individual sharks, to obtain a population estimate based mark-recapture. Saturation of new sightings occurred once 400 individuals were catalogued. Notably, the estimate based on 877 re-sightings (1304 total capture events) obtained with the open population model POPAN ranges between 353-522 individuals (95% confidence), which is similar to that obtained using genetic approaches. Both population estimates are an order of magnitude less than expected. Based on the results of this study we strongly suggest maximizing and reinforcing protection measures currently in place, as well as the continued monitoring of population sizes at regional and international levels.

 

Keywords: white shark, microsatellites, population size, mark-recapture, photo identification