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Whale Shark (Rhincodon typus) Habitat Use at an Aggregation in the Saudi Arabian Red Sea, Royale Hardenstine [et al.]

Whale Shark (Rhincodon typus) Habitat Use at an Aggregation in the Saudi Arabian Red Sea, Royale Hardenstine [et al.]

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D2/ Indo-Pacific Predators: Biology,

ecology, conservation and

management



303



First characterization of the Cookie-cutter

sharks (Isistius sp.) predation pattern on

different cetacean species in Martinique

(FWI).

Virginie Scanga ∗ 1 , Aurore Feunteun 2 , Catalina Schrevel 2 , Marie

Verhaegen 2 , Damien Chevallier 3 , Matthieu Duchemin 4 , Nicolas Ziani 5 ,

Benjamin De Montgolfier† 1,2

1



Aquasearch-Polyn´esie – BP 21215, 98713 Papeete, French Polynesia

2

Aquasearch – ZAC Les coteaux, 97228 Sainte-Luce, Martinique

3

´

´

D´epartement Ecologie, Physiologie et Ethologie

(DEPE), Institut Pluridisciplinaire Hubert Curien

(IPHC), UMR 7178 CNRS et Universit´e de Strasbourg – Universit´e de Strasbourg, IPHC, CNRS, UMR

7178 – 23 rue Becquerel, F-67087 Strasbourg Cedex 2, France

4

DM Conseil – DM Conseil – 7 all´ee du bois rond, 69360 Serezin du Rhˆone, France

5

Groupe phoc´een d’´etude des requins (GPER) – Groupe phoc´een d’´etude des requins – 118 rue du

Rouet, 13008 Marseille, France



Cookie-cutter sharks (Isistius sp.) are small squaloid sharks that live in tropical and subtropical oceans. Their name comes from their unique tactic of feeding, which enables them

to parasitize marine mega-fauna, like cetaceans. Due to their morphological and anatomical

characteristics, they are responsible of crater-like wounds on the skin of marine mammals. Little

is known on Isistius sp. around the globe especially in Martinique, which represents a potential

habitat. The main goal of this study was to assess the impact of cookie-cutter sharks on cetaceans

by determining (1) seasonal changes in the occurrence of bites, (2) intra- and interspecific

differences in frequencies and locations of bites within cetacean, and (3) link behavior patterns of

both cookie-cutter sharks and cetaceans. Data were collected from a 3-year photo-identification

database of Cetaceans in Caribbean coast of Martinique. Four hundred and thirty one wounds of

various stages on 396 individuals from 9 species of marine mammals were recorded. Results did

not show any significant variation in the occurrence of wounds between seasons. Intermediate

state was more important, most injuries were observed on the SCF and in a lesser extent on

young individuals (3.25%). The parasitic lifestyle of cookie-cutter sharks has been confirmed

consistently on cetacean species in Martinique. Further studies are required with both scientists

and fishermen to better understand their specific role in this marine ecosystem.









Speaker

Corresponding author: b.montgolfier@aquasearch.fr



304



From sink to source: effects of declining fin

demand on shark fishing livelihoods in

Indonesia

Vanessa Jaiteh



∗ 1,2,3



, Neil Loneragan



2,3



, Carol Warren



2



1



Coral Reef Research Foundation Palau (CRRF) – PO Box 1765 Koror, PW-96930 Palau, Palau

Asia Research Centre, School of Management and Governance, Murdoch University – 90 South Street,

Murdoch, Western Australia 6150, Australia

3

Centre for Fish and Fisheries Research, School of Veterinary and Life Sciences, Murdoch University –

90 South Street, Murdoch, Western Australia 6150, Australia



2



For three decades, a booming demand for shark fin on Asian markets has provided important livelihoods for remote fishing communities in Indonesia, a major source country for

internationally traded shark fin. Fishery and interview data collected from three case studies in

the Halmahera, Arafura and Timor Seas were used to examine changes in shark fishers’ livelihoods over the preceding 20 years. While recent reductions in shark fin demand have had a

substantial impact on fishers’ livelihoods, the fishery’s vast geographic range and its political

complexity in general have meant that government and international development agencies have

largely been unaware of this impact. Many respondents remembered the Asian Financial Crisis in 1997-98 and the turn of the millennium as a time when sharks were still abundant and

shark fin prices high, but were concerned about the on-going fall of shark fin prices since March

2012. High-value species, particularly guitarfish, hammerhead and sandbar sharks were most

affected, losing up to 40% of their pre-2012 value. These changes, combined with the loss of

fishing grounds, few attractive options for alternative income and restrictive debt relationships

with shark fin bosses, have led some fishers to resort to high-risk activities such as blast fishing,

illegal transboundary fishing, and even people smuggling. This paper examines the multi-layered

causes and consequences of fishers’ decision-making in response to adverse economic and ecological changes in their fishery, and explores options and obstacles to pursuing livelihoods that

carry lower environmental, financial and personal risks.







Speaker



305



Genetic connectivity of a coastal apex

predator: The population genetic structure

reveals a potential spatial isolation of Fijian

bull sharks

Kerstin Glaus ∗† 1 , Sharon Appleyard 2 , Mahmood Shivji 3 , Juerg

Brunnschweiler 4 , Amandine Marie 5 , Ciro Rico 5,6

1



The University of the South Pacific (USP) – School of Marine Studies, Faculty of Science, Technology

and Environment, Laucala Campus, Suva, Fiji

2

CSIRO National Research Collections Australia, Australian National Fish Collection – Hobart, TAS.,

Australia

3

Guy Harvey Research Institute, Nova Southeastern University Oceanographic Center – 8000 North

Ocean Drive, Dania Beach, FL 33004, United States

4

Independent Researcher – Gladbachstrasse 60 Zurich, Switzerland

5

The University of the South Pacific – School of Marine Studies, Faculty of Science, Technology and

Environment, Laucala Campus, Suva, Fiji

6

Estaci´

on Biol´

ogica de Do˜

nana, Consejo Superior de Investigaciones Cient´ıficas – Sevilla 41092, Spain,

Spain



Knowledge about the genetic population structure is fundamental to fields ranging from

evolutionary biology to species conservation management. To date and for sharks, the genetic

population structure of only a few coastal species is known. Moreover, the application of whole

genome-scans for non-model organisms allows genetic studies to enter a vast new stage of genomic

exploration. The bull shark (Carcharhinus leucas) is a large, mobile, circumglobally distributed

species that inhabits a variety of coastal habitats including freshwater environments. Combining

the bull sharks’ capability for long-distant movements and the species’ longevity, significant

genetic exchange is generally assumed. Here, using Single Nucleotide Polymorphisms (SNPs), we

test the null-hypothesis that bull sharks are panmictic throughout a subset of the species’ IndoPacific range. We analyzed 2793 high-quality neutral SNP markers in 150 individual bull sharks

from Fiji, the east, north, and west coasts of Australia, Banda Aceh in Indonesia, and South

Africa. Genomic diversity and population connectivity estimates including average observed

heterozygosity (Ho) and pairwise FST were calculated. Observed heterozygosities ranged from

0.291 + 0.165 to 0.335 + 0.173. The analyses revealed significant genetic partitioning between

Fiji and all other locations sampled (FST > 0.037, P < 0.001). Contrastingly, gene flow within

all the remaining locations was apparent, with highest levels of genetic connectivity between

West Australia and Banda Aceh, Indonesia. The absence of population structure across the

Sunda Shelf barrier indicates that oceanic expanses and land barriers in Southeast Asia are not

impediments to bull shark dispersal. Our results demonstrate, that a remote island archipelago,

such as Fiji, offers a great opportunity to study genetic population structure in a mobile, coastal

shark. We anticipate our genomic approach to be the starting point for our future research







Speaker

Corresponding author: kerstin glaus@outlook.com



306



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