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ORIGINAL PAPER
Shark diversity in the Arabian/Persian Gulf higher than
previously thought: insights based on species composition of shark
landings in the United Arab Emirates
Rima W. Jabado &Saif M. Al Ghais &Waleed Hamza &
Mahmood S. Shivji &Aaron C. Henderson
Received: 30 July 2014 /Revised: 29 August 2014 /Accepted: 23 September 2014
#Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg 2014
Abstract Although fish fauna in the Arabian/Persian Gulf
have been studied for decades, shark diversity has only been
recently investigated in the region. Here, we present a first
comprehensive account of shark diversity from the United
Arab Emirates based on fishery-dependent data collected at
market and landing sites over a two-year period of field
sampling. Landings across the country were dominated by
carcharhinids, and six species were found to be most abun-
dant, including the spot-tail shark, Carcharhinus sorrah,and
the milk shark, Rhizoprionodon acutus, contributing 31.8 %
and 29.9 %, respectively, of the total number of sharks. While
observed landings varied among regions and across seasons,
results showed that shark landings were dominated by small-
sized species, which may be a reflection of overexploitation.
We are now expanding the existing checklist of shark species
in the Persian Gulf from 27 to 31, having utilized both mor-
phological identification and genetic barcoding in validating
the existence of the grey bamboo shark, Chiloscyllium
griseum; the tawny nurse shark, Nebrius ferrugineus; the silky
shark, Carcharhinus falciformis; and the sandbar shark,
Carcharhinus plumbeus, in these waters. This inventory pro-
vides an urgently needed assessment of current regional di-
versity patterns that can now be used as a baseline for future
investigations evaluating the effect of fisheries on shark pop-
ulations. Results emphasize the need for research on life
history traits of the various species in order to determine their
regional conservation status, but also reveal that a precaution-
ary approach to conservation will be necessary to mitigate
anthropogenic impacts.
Keywords Shark .Species richness .United Arab Emirates .
Management .Conservation
Introduction
The Arabian/Persian Gulf (hereinafter referred to as the
‘Gulf’) is a highly stressed ecosystem as a result of the
prevailing environmental conditions as well as the anthropo-
genic activities that have introduced a number of stressors
threatening its ecological integrity and sustainability (Hamza
and Munawar 2009). With the rapid economic growth that has
taken place in the eight bordering countries of Iran, Iraq,
Kuwait, Saudi Arabia, Bahrain, Qatar, the United Arab Emir-
ates (UAE), and Oman, the marine environment is swiftly
changing.
Although the overall biodiversity at the species level is still
poorly understood compared to that of the Arabian Sea, the
Gulf is considered biologically impoverished, in part because
of its young age, but primarily due to its environmental
characteristics (Randall 1995; Sheppard et al. 2010). It is
believed that most organisms living in the Gulf survive at
Electronic supplementary material The online version of this article
(doi:10.1007/s12526-014-0275-7) contains supplementary material,
which is available to authorized users.
R. W. Jabado (*):S. M. Al Ghais :W. Hamza
Biology Department, College of Science, United Arab Emirates
University, P.O. Box 15551, Al Ain, United Arab Emirates
e-mail: rimajabado@hotmail.com
M. S. Shivji
Save Our Seas Shark Center, Nova Southeastern University
Oceanographic Center, 8000 North Ocean Drive, Dania Beach,
FL 33004, USA
A. C. Henderson
The School for Field Studies, Center for Marine Resource Studies,
South Caicos, Turks and Caicos Islands
Present Address:
R. W. Jabado
Gulf Elasmo Project, P.O. Box 29588, Dubai, United Arab Emirates
Mar Biodiv
DOI 10.1007/s12526-014-0275-7
the limits of their physiological tolerance and that marine taxa
here are derived from the penetration of Indian Ocean species
through the Strait of Hormuz (Price 1993; Beech 2004a).
Basson et al. (1977) reported low species richness in these
waters, which was confirmed by most later research on ben-
thic groups such as corals and echinoderms (Price and Coles
1992; Sheppard et al. 1992). On the other hand, the Gulf is
also recognized as home to at least four species of marine
turtles, over 10 cetacean species, the second-largest dugong
population in the world, as well as large numbers of endemic
and migratory birds, suggesting that it could be harboring high
levels of marine biodiversity (Hellyer and Aspinall 2005).
From a fisheries perspective, various research projects have
indicated that anywhere from 200 and up to 550 species have
been reported in the Gulf, including reef-associated fishes,
sharks, and rays (Krupp et al. 2000; Grandcourt 2012). In com-
parison to the fish fauna documented in Oman’s Arabian Sea, it is
clear that the Gulf is limited in its fish biodiversity, and few
species are endemic to these waters (Randall 1995; Carpenter
et al. 1997; Bishop 2003; Beech 2004b). Furthermore, it appears
that there are regional variations in species richness throughout
the Gulf, with fewer species identified in western and southern
areas, while northern and eastern areas, as well as the deeper
waters closer to the Strait of Hormuz, are richer in certain species
(Price 1993; Beech 2004b). This is believed to be related to
several factors, including bottom topography and sediment type
in the Gulf (Beech 2004b).
Fisheries in the region are described as artisanal, multi-gear,
and multi-species (Beech 2004b;Grandcourt2012). Fishermen
operate two types of boats: small fiberglass dories, or ‘tarad’,
and traditional wooden dhows, or ‘lansh’(Grandcourt 2012;
Jabado et al. 2014). The primary fishing gear utilized on these
vessels include drift nets, gill nets, handlines, traps, longlines,
and trolls (Jabado et al. 2014). Although sharks are an important
component of fisheries and fish trade, their diversity in the Gulf
is still poorly understood (Jabado et al. 2014).Basedona
literature review and results from market surveys, the most
recent account of shark species in this basin confirms the pres-
ence of 26 species (Moore et al. 2012b). Although these reports
are based on limited observations and do not reflect changes in
geographic and temporal trends that may be occurring in the
basin, they do hold relative value, as they remain the only
species records and measures of abundance levels for sharks in
the region. Furthermore, despite the fragmented nature of these
surveys, the rate of species discovery is relatively high, with
recent documentation and confirmation of new shark species,
including the slender weasel, Paragaleus randalli (Compagno,
Krupp and Carpenter, 1996); sliteye, Loxodon macrorhinus
(Müller and Henle, 1839); snaggletooth, Hemipristis elongatus
(Klunzinger, 1871); graceful, Carcharhinus amblyrhynchoides
(Whitley, 1934); and hardnose, C. macloti (Müller and Henle,
1839) (Compagno et al. 1996; Moore et al. 2010). More recent-
ly, a new species of whaler shark, Carcharhinus humani sp. nov.
(White and Weigmann 2014), was also described in the Gulf,
bringing the total number of species to 27 (White and
Wei g mann 2014). The limited amount of research currently
being directed toward shark diversity, distribution, and biology
gives rise to doubts about the completeness and accuracy of
available regional checklists (Jabado et al. 2014). In the UAE,
there is no established list of shark species other than some
confirmed sightings within the Gulf recorded during a survey
conducted in 2002 by the Environment Agency –Abu Dhabi
(EAD) (Edwin Grandcourt, pers. comm.) and during a 10-day
visit to a landing site in Abu Dhabi by Moore et al. (2012a). This
general lack of knowledge on the number of shark species,
composition and quantities of catches, and the amount of fishing
efforts directed toward this fishery suggests that shark species
richness in the region could be higher than previously recorded.
This is especially true since it has been shown around the world
that with increased research and genetic studies, new species are
being discovered and described at a rapid rate (Naylor et al.
2012).
Globally, shark populations are facing increasing pressure,
and the advancement of conservation measures requires infor-
mation on their biodiversity and conservation status
(Simpfendorfer et al. 2011). In the UAE, fishermen have
indicated a general decline in shark catches, abundance, and
size over the last two decades, suggesting that the shark
fishery is currently overexploited (Jabado et al. 2014). How-
ever, protection of sharks in the Gulf is hampered by limited
available baseline scientific data, along with the challenge of
balancing conservation efforts with the provision of essential
resources for growing coastal populations. In order to main-
tain the ecological integrity of the Gulf, it is essential to
understand and evaluate potential changes in the marine bio-
diversity of this increasingly threatened aquatic ecosystem.
Here, we investigate the diversity of shark species captured
in the UAE artisanal fishery. We present the results of fishery-
dependent market and fish landing site surveys that can aid in
conservation initiatives both in the UAE and in the broader
region. Specifically, we (1) examine patterns of species com-
position, distribution, and relative abundance across sites; (2)
investigate temporal and spatial variability in landings com-
position; and (3) validate the field identification of each spe-
cies through genetic analysis of a representative sample of
individual species using the Cytochrome c oxidase subunit 1
gene (COI). We conclude with a discussion of general impli-
cations for the conservation of shark species in the Gulf.
Material and methods
Study sites
The Gulf is an epicontinental semi-enclosed sea lying in a
subtropical zone with hyper-arid climate, stretching 1,000 km
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in length from the Shatt al-Arab waterway to the Strait of
Hormuz, and varying in width from 75 to 350 km (Carpenter
et al. 1997)(Fig.1). The basin has an average depth of 35 m,
gradually becoming deeper, to 100 m, as it approaches its
entrance (Sheppard et al. 1992).Themarineenvironmentis
harsh and extreme, characterized by low hydrodynamic ener-
gy; relatively shallow depths; high evaporation rates, surface
water temperatures, and salinities; and minimal water
exchange.
The UAE lies along the southeastern Gulf coast and ex-
tends to the Gulf of Oman between 22° and 26° N latitude
and 51° and 57° E longitude. The country’s coastline stretches
roughly 740 km, including some 650 km of the western Gulf
coast (EAD 2011). The main study area was along the Gulf
coastline of the UAE. From April through June 2010, several
exploratory market and landing site visits were carried out to
determine sites with the largest concentrations of shark land-
ings. It was subsequently determined that this study would
focus on landing sites in the regions nationally defined as
Western (Mina Zayed, Abu Dhabi), Central (Jubail, Sharjah),
and Northern (Maarid, Ras Al-Khaimah (RAK)). While sev-
eral landing sites exist within each region, these three loca-
tions are found along the Gulf coastline where vessels offload
their catches directly, facilitating the collection of information
on capture location. Vessels operating and offloading in this
area fish exclusively in Gulf waters, and thus it was possible to
ensure that all species recorded were from the waters of the
Gulf and not the Arabian Sea. Furthermore, fishers from
nearby landing sites transport their landings to these markets
at the time of auction, enabling sampling of larger numbers of
specimens during each survey. Species composition of land-
ings from Dubai, as well as from specimens transported to
Dubai from these three regions, were opportunistically record-
ed at the Dubai Deira fish market while conducting separate
trade surveys and were included in this analysis.
Market and landing site surveys
Site visits were made prior to the start of the main daily
auction, when the majority of landings were on display, and
were at different times: 04:30–08:00 in Abu Dhabi, 16:00–
18:30 in Sharjah, 12:30–15:00 in RAK, and 17:00–20:00 in
Dubai. All sharks found at landing sites were caught from
UAE Gulf waters, whereas those found at markets were
sometimes transported from other emirates or from Oman.
Data were recorded on the origin of each shark at the markets,
and only those captured in UAE waters were considered in
this study.
Data collection commenced in October 2010 and was
ongoing until September 2012. With the exception of sites in
Dubai, each site was visited twice a month on a rotational
basis until January 2012, when visits were reduced to once a
month. In Dubai, data were collected four times a month, and
then reduced to twice a month in January 2012. After plotting
the cumulative number of species present at each market visit
against the number of market visits, it was determined that
even with a reduction in sampling frequency, surveys would
be sufficient to describe species composition at landing sites.
Each visit lasted three to four hours, depending on the quantity
of sharks landed. Specimens were always landed whole, and
therefore it was possible to identify them to the lowest possi-
ble taxonomic level using keys from Carpenter et al. (1997),
Compagno et al. (2005), and Last and Stevens (2009). Be-
cause shark trade among the emirates does occur, sharks
sampled were marked with cuts on their left gills, and visits
to markets did not occur on consecutive days and weeks in
order to avoid double-counting study specimens.
An analysis of species richness was undertaken using
Jaccard’s similarity index to determine the percentage of spe-
cies shared between landing sites (Magurran 2004). In addi-
tion, landings composition was compared across seasons,
which were defined as spring (March–May), summer (June–
August), autumn (September–November), and winter (De-
cember–February). Full seasons were sampled for both years,
with the exception of autumn, which was sampled for two
months in 2010 and one month in 2012 due to the limited time
frame of the project.
Genetic analyses
Tissue samples were collected from fresh animals at the four
sampling sites. All samples were immediately placed in
Eppendorf Tubes, preserved in 95 % ethanol, and stored at
−20 °C until required for analysis. To validate species identity,
a set of 130 tissue samples comprising five samples from each
morphologically identified species, when available, were
analyzed.
Genomic DNA was extracted using the DNeasy Blood &
Tissue Kit (Qiagen Inc., Valencia, CA, USA) from 25 mg of
fresh tissue collected from whole specimens, according to
manufacturer instructions. Extracted DNA was checked on
0.8 % TBE agarose gels containing ethidium bromide for
DNA quality and concentration. A DNA fragment from the
COI gene comprising approximately 650 bp was amplified by
PCR using the individual primers Fish F1 (5’-TCAACCAA
CCACAAAGACATTGGCAC-3’), Fish F2 (5’-TCGACTAA
TCATAAAGATATCGGCAC-3’), Fish R1 (5’-TAGACTTC
TGGGTGGCCAAAGAATCA-3’), and Fish R2 (5’-ACTT
CAGGGTGACCGAAGAATCAGAA-3’) (Ward et al. 2005).
Amplification reactions were performed in50-μLvolumes,
containing 1 μL of the extraction genomic DNA, 10 pmol of
each primer, 10X PCR buffer (Qiagen Inc.), 50 μMdNTPs
mix (Illustra dNTP set, GE Healthcare), 1 unit of HotStarTaq
DNA Polymerase kit (Qiagen Inc.), and 33.3 μLHPLCpuri-
fied water (OmniSolv). The PCR thermal cycling employed
was: 95 °C initial denaturation for 15 min, followed by
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35 cycles of 94 °C for 1 min, 50 °C for 1 minute, 72 °C for
2 min, and a 2-min final extension step at 72 °C. Amplifica-
tions were performed using the BioRad iCycler thermal cy-
cler. Amplified fragments were confirmed on 1.2 % agarose
gel stained with ethidium bromide and viewed on a Foto/
spectrum Transilluminator (FotoDyne). PCR reactions were
cleaned with QIAquick PCR Purification Kit (Qiagen) and
eluted in 30 μL of Buffer EB. For each sample, 10 μLof
cleaned cycle sequencing reaction per well was loaded in a
MicroAmp 96-Well Reaction Plate (Applied Biosystems,
USA), and sequencing was completed using the dye-labeled
termination method (BigDye Terminator v3.1, Cycle Se-
quencing Kit, Applied Biosystems) on a 3130xl Genetic
Analyzer (Applied Biosystems) in either forward or
reverse direction.
Sequences were inspected and cleaned of ambiguous bases
by visualizing the corresponding chromatogram using the
BioEdit program (Hall 1999). Species identification was per-
formed using both the BOLD Identification Engine (www.
boldsystems.org) and GenBank nucleotide database (www.
ncbi.nlm.nih.ggoc/nucleotide). The BOLD and GenBank
engines each matched uploaded sequences with others
present in their databases, and provided high specimen
similarity or maximum identity percentages, respectively,
with matching sequences. All sequences were then aligned
using Clustal XI software and trimmed to 417 bp in order to
include as many species in the analysis as possible without
compromising its power. Taxonomic clustering among
barcoded samples was analyzed by constructing
phylogenetic trees using three different methods: neighbor-
joining (NJ), maximum likelihood (ML) and maximum par-
simony (MP). Estimation of the NJ (Kimura two-parameter
distance model [Kimura 1980]) and MP trees was performed
using 1,000 bootstrap replications (MEGA 4) (Tamura et al.
2007).
Results
Overall species composition
A total of 12,478 individual sharks originating from UAE
Gulf waters were recorded from 205 site visits. After 150
visits, from which 28 species of sharks were confirmed, the
frequency of surveys was reduced, as it was determined that
extra market visits would not serve to increase the diversity of
species encountered. An additional two species were docu-
mented in 2012, however, raising the number of confirmed
species to 30, which consisted of nine families from three
orders (Table 1). The family Carcharhinidae was the most
diverse, with 18 species, followed by Hemigaleidae with
three species, and Sphyrnidae and Hemiscylliidae with
two species each.
Fig. 1 Map indicating the
location of landing sites across the
UAE where sampling was
undertaken
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Tabl e 1 Taxonomic list of shark species, including IUCN Red List Status, recorded from UAE waters from 205 surveys
Family/Species IUCN status Abu Dhabi Dubai Sharjah Ras Al-Khaimah Autumn Winter Spring Summer TOTAL
n%n%n%n%n %
Hemiscylliidae
Chiloscyllium
arabicum
NT 1 3 1 0 1 0.02 2 0.06 1 0.02 1 0.04 50.04
Chiloscyllium
griseum
NT 0 0 1 0 0 0.0 0 0.0 1 0.02 0 0.0 10.01
Ginglymostomatidae
Nebrius ferrugineus VU 0 0 2 0 0 0.0 1 0.03 0 0.0 1 0.04 20.02
Stegostomatidae
Stegostoma
fasciatum
VU 0 5 4 0 1 0.02 0 0.0 7 0.2 1 0.04 90.07
Rhincodontidae
Rhincodon typus VU 0 1 0 0 0 0.0 1 0.03 0 0.0 0 0.0 10.01
Odontaspididae
Carcharias taurus VU 1 0 0 0 0 0.0 0 0.0 1 0.02 0 0.0 10.01
Triakidae
Mustelus mosis DD 1 17 55 131 37 0.9 48 1.6 101 2.8 18 0.8 204 1.63
Hemigaleidae
Chaenogaleus
macrostoma
VU 2 7 23 28 8 0.2 25 0.8 21 0.6 6 0.2 60 0.48
Hemipristis elongata VU 3 5 26 15 18 0.47 7 0.2 13 0.3 11 0.4 49 0.39
Paragaleus randalli NT 0 9 22 54 9 0.23 17 0.5 31 0.8 28 1.2 85 0.68
Carcharh inidae
Carcharhinus
amblyrhynchoides
NT 33 8 41 8 15 0.39 6 0.2 62 1.7 7 0.3 90 0.72
Carcharhinus
amblyrhynchos
NT 0 4 3 1 3 0.07 0 0.0 0 0.0 5 0.2 80.06
Carcharhinus
amboinensis
DD 61 16 42 8 19 0.5 32 1.0 61 1.7 15 0.6 127 1.02
Carcharhinus
brevipinna
NT 8 33 17 8 6 0.15 12 0.4 36 1.0 12 0.5 66 0.53
Carcharhinus
dussumieri
NT 136 63 212 150 187 4.94 189 6.3 96 2.7 86 3.8 561 4.50
Carcharhinus
falciformis
NT 0 6 0 0 6 0.15 0 0.0 0 0.0 0 0.0 60.05
Carcharhinus
leiodon
VU 1 2 0 0 2 0.05 1 0.03 0 0.0 0 0.0 30.02
Carcharhinus le ucas NT 93 44 18 12 19 0.5 62 2.0 68 0.0 18 0.8 167 1.34
Carcharhinus
limbatus
NT 906 300 516 64 581 15.3 455 15.3 516 14.7 234 10.4 1786 14.31
Carcharhinus
macloti
NT 0 60 11 102 73 1.93 42 1.4 43 1.2 15 0.6 173 1.39
Carcharhinus
melanopterus
NT 10 15 10 3 8 0.2 5 0.1 9 0.2 16 0.7 38 0.3
Carcharhinus
plumbeus
VU 1 0 6 6 4 0.1 5 0.1 1 0.02 3 0.1 13 0.1
Carcharhinus sorrah NT 615 716 1460 1182 997 26.3 675 22.7 1179 33.7 1122 50.2 3973 31.84
Galeocerdo cuvier NT 0 0 1 0 0 0.0 0 0.0 1 0.02 0 0.0 10.01
Loxodon
macrorhinus
LC 8 320 88 704 415 10.9 235 7.9 270 7.7 200 8.9 1120 8.98
Negaprion acutidens VU 30 3 7 1 19 0.5 4 0.1 11 0.3 7 0.3 41 0.33
Rhizoprionodon
acutus
LC 818 870 989 1060 1315 3.46 1083 36.4 924 26.4 415 18.5 3737 29.95
Rhizoprionodon
oligolinx
LC 0 0 1 11 4 0.1 8 0.2 0 0.0 0 0.0 12 0.1
Sphyrnidae
Sphyrna lewini EN 0 7 2 6 8 0.2 1 0.03 4 0.1 2 0.08 15 0.12
Sphyrna mokarran EN 80 8 30 6 17 0.4 50 1.6 45 1.2 12 0.5 124 0.99
TOTAL 2808 2522 3588 3560 3782 30.3 296 8 23.7 3495 2 8.0 2233 17. 8 12478 100
(EN Endangered; NT Near Threatened; VU Vulnerable; DD Data Deficient; LC Least Concern); species composition and quantities of sharks recorded
in Abu Dhabi, Dubai, Sharjah, and Ras Al-Khaimah, based on their location of origin, seasonal and total catch composition (n= number of individuals; %
of shark landings)
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Carcharhinids dominated landings in terms of number,
with 95.5 % (n=11,922) of the total shark landings, followed
by the triakids, consisting of one species, Mustelus mosis
(Hemprich and Ehrenberg, 1899), but accounting for 1.6 %
of the total landings. While the total number of species was
relatively high, many of them were found only in small
quantities and landings were dominated by a few species.
The most abundant species was Carcharhinus sorrah (Müller
and Henle, 1839), contributing 31.8 % to the total number of
sharks, followed by Rhizoprionodon acutus (Rüppell, 1837),
with 29.9 % of the total. In terms of number, C. limbatus
(Valenciennes, 1839), L. macrorhinus,C. dussumieri (Valen-
ciennes, in Müller and Henle, 1839), and M. mosis were also
relatively abundant, contributing 14.3 %, 8.9 %, 4.5 %, and
1.6 %, respectively, to the total shark numbers. The remaining
24 species comprised between 0.01 % and 1.4 % of the total
shark landings.
Spatial and seasonal species composition
With respect to the 30 shark species identified, Sharjah was
the region most rich in species, with a total of 26 species,
followed closely by Dubai, with 24 species. RAK had 21
species, while Abu Dhabi displayed the lowest species rich-
ness, with 19 species recorded. With regard to the similarity in
species composition among landing sites, Jaccard’s index
indicated that the degree of species overlap among regions
was moderately high, with regions sharing anywhere from
60.7 % to 80.7 % of species (Table 2).
Although the sampling effort was consistent in each loca-
tion and cross-seasonally, there was some degree of variability
in the number of observed landings among regions and across
seasons (Table 1). Among regions, Dubai had the fewest shark
landings, with 20.2 % of the total, followed by Abu Dhabi
with 22.5 %. When viewed from a regional perspective, the
Central region, comprising both the Dubai and Sharjah land-
ing sites, contributed 49.5 % of the total number of landings.
There was no significant difference in the number of spe-
cies across seasons, with 25 species recorded in autumn, 24 in
both winter and spring, and 23 in summer. There was varia-
tion, however, in the total number of landings, with autumn
yielding the highest number, with 30.3 % of the total captures,
whereas a significant decline was observed in the summer
(17.8 %). The numbers also varied with regard to seasonal
shark landings by site location. Abu Dhabi had the highest
landings in autumn (37.9 %), followed by winter (31.1 %) and
spring (25.9 %), while almost no shark landings were record-
ed in the summer (4 %). In Dubai, landings were stable during
autumn (30.9 %) and spring (32 %), but declined during
winter (16.2 %) and summer (20.7 %). Landings in Sharjah
were relatively stable across seasons, although spring yielded
the highest number, with 29 % of the total, followed by
summer (25.7 %), winter (23.8 %), and autumn (21.4 %).
RAK showed a different pattern as well, with landings
peaking in autumn (32.7 %), followed by spring (27 %),
winter (23 %), and summer (17.2 %). When landings in Dubai
and Sharjah were combined, Central region numbers showed
similar patterns to RAK, with a peak in spring (30.2 %), but
then followed by autumn (25.3 %), summer (23.7 %), and
winter (20.7 %) (Fig. 2).
Overall species composition varied across locations and
seasons. While six species dominated overall among the land-
ings, some variability in the dominant species was noted with
regard to regional occurrence and abundance (Fig. 3). The
most frequently observed species at all sites were C. sorrah
and R. acutus. With the exception of landings of M. mosis and
C. macloti, the most abundant species were similar between
Dubai and Sharjah, and landings composition for these two
sites were combined as the Central region.
Noteworthy species occurrence included M. mosis, ac-
counting for a low proportion of catches in most locations
(n= 1 in Abu Dhabi) but common in RAK, thereby increasing
its abundance in the national catch composition overall;
C. macloti, which was absent in Abu Dhabi landings but
was recorded at all other locations across seasons, with
58.9 % of catches recorded in RAK; C. leucas (Müller and
Henle, 1839), which was found in catches across seasons but
predominantly in Abu Dhabi (55.6 %), where it was abundant;
C. leiodon (Garrick, 1985), which was only present in Dubai
and Abu Dhabi in autumn and winter; C. falciformis (Müller
and Henle, 1839), which was recorded in Dubai in autumn but
not present at other landing sites or during other seasons;
R. oligolinx (Springer, 1964), which was only found in RAK
(n=11) and Dubai (n=1) during autumn and winter; and
Tabl e 2 Jaccard’s similarity index values illustrating the degree of sim-
ilarity in the species composition among sampling sites in the UAE
Abu Dhabi Dubai Sharjah Ras Al-Khaimah
Abu Dhabi * 0.65 0.60 0.66
Dubai * * 0.72 0.73
Sharjah * * * 0.80
Ras Al-Khaimah * * * *
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Abu Dhabi Dubai Sharjah Ras Al
Khaimah
Central region
Number of sharks
Location
Autumn
Winter
Spring
Summer
Fig. 2 Seasonal shark landings recorded for each landing site location,
with Dubai and Sharjah landings shown separately as the Central region
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P. randalli,C. amblyrhynchos (Bleeker, 1856), and Sphyrna
lewini (Griffith and Smith, 1834), which were not recorded in
Abu Dhabi but present at other sites.
Range extensions and new species confirmations in the Gulf
Four previously unconfirmed species in this basin were re-
corded, extending their current known distribution. They in-
cluded the grey bamboo shark, Chiloscyllium griseum (Müller
and Henle, 1839);the tawny nurse shark, Nebrius ferrugineus
(Lesson, 1830);the silky shark, C. falciformis; and the sand-
bar shark, C. plumbeus (Nardo, 1827). Furthermore,
Galeocerdo cuvier (Peron and Lesueur, 1822) and
C. amblyrhynchoides specimens were confirmed for the first
time in southern Gulf waters.
DNA Barcoding
DNA COI barcoding was attempted on 130 samples from the
30 species identified morphologically in this study. The final
barcode data set comprised 120 sequences from 29 species,
with sequence lengths varying from 485 to 637 bp. Sequences
have been deposited in the GenBank database under accession
numbers: KM973088-KM973199. Ten samples were exclud-
ed from the analysis: three of them yielded ambiguous species
identifications, while seven samples failed to provide good
sequences, including the only sample of C. griseum collected.
All sequences were compared with those in BOLD and GenBank
databases to confirm initial morphological identification, and the
results of matching sequences, along with the amplicon size
produced for each sample, are provided in Appendix A.
Genetic analysis based on morphological characteristics un-
equivocally confirmed 24 species among those recorded in this
study. Of these, 12 sequences were the first available from the
Gulf for C. arabicum (Gubanov and Schleib 1980),
N. ferrugineus, Stegostoma fasciatum (Hermann, 1783),
Rhincodon typus (Smith, 1828), Carcharias taurus (Rafinesque,
1810), C. amblyrhynchos, C. falciformis, C. melanopterus (Quoy
and Gaimard, 1824), C. plumbeus, Negaprion acutidens
(Rüppell, 1837),G.cuvier,and S. lewini. Taxonomic identifica-
tion from barcodes, however, was ambiguous for five species.
Only two of five samples of C. arabicum provided good
sequence quality, and although results from both BOLD and
GenBank assigned these sequences to the Chiloscyllium ge-
nus, species resolution was not possible. Rhizoprionodon
oligolinx sequences provided a 100 % match with the same
species in BOLD, but the closest match in GenBank was 93 %
with R. porosus (Poey, 1861). For P. randalli and
Chaenogaleus macrostoma (Bleeker, 1852), there was no
consistency in the nomenclature of records between BOLD
and GenBank. Finally, although sequences for C. limbatus
samples had slightly different barcodes between them, they all
29.9%
31.8%
14.3%
8.9%
4.5%
1.6%
8.7%
29.7%
33.2%
19.7%
4.2%
3.6%
1.8% 7.5%
29.1%
21.9%
32.2%
4.8%
3.3% 2.8% 5.7%
30.4%
35.6%
13.3%
6.6%
4.5% 0.9%
7.5% 0.9%
Fig. 3 Relative landings composition (%) of the top six species for each of the three regions (Western, Central, and Northern). The chart at the upper left
shows the overall species composition for the three regions combined.
Mar Biodiv
matched this species in both databases. However, sequences
from C. amblyrhynchoides yielded ambiguous results, and
matched both C. limbatus and C. amblyrhynchoides.
Tax ono mic cl ust erin g
While there were differences in classifications at the family
and order levels, all three trees provided similar outcomes in
terms of taxonomic clustering. In all trees, specimens from
database sequence matches that could have been either
C. limbatus or C. amblyrhynchoides were all assigned to one
cluster and were not distinguishable. Some P. randalli and
C. macrostoma samples clustered as one species, while one
C. macrostoma sample stood out as a separate species. Results
based on the NJ tree are illustrated in Appendix B.
Discussion
This fishery-dependent assessment is the first comprehensive
study on shark species found in southern Gulf waters, and it
has enabled the development of an updated regional checklist
of species by providing an overview of the composition of
shark landings at various sites in the UAE. The study greatly
improves the current knowledge regarding species richness,
relative abundance, and distribution of sharks exploited by the
UAE fishery. Although data are still incomplete, and in some
cases insufficient to draw conclusions regarding the abun-
dance and conservation status of each species in the region,
our results indicate that sharks are an important component of
the marine biodiversity of the Gulf. Here, we discuss the
various results from this study and their implications for shark
conservation in the region, and then offer some recommenda-
tions for further study and management measures.
Species diversity and occurrence
The latest annotated checklist confirmed the presence of 26
shark species in the Gulf (Moore et al. 2012b). The present
study has raised this number to 31 and has validated the
occurrence of species such as C. griseum,C. plumbeus,
N. ferrugineus,andC. falciformis that had been previously
mentioned in the literature but with no supporting evidence
such as photographs or samples (Gubanov and Schleib 1980;
Randall 1986;Bishop2003; Compagno et al. 2005). Since the
number of species encountered rose very little after the first
year of study, it is likely that the actual species composition of
sharks in the region, along with the abundant species found in
UAE Gulf waters, have been accurately documented. How-
ever, it is important to note that these surveys may have
underestimated protected, discarded, rare, or even migratory
species. For instance, while only one whale shark, R. typus,
was recorded in this study, that species has historically been
reported in the Gulf, and more recently, large aggregations
have been documented in the offshore waters of Qatar (Rob-
inson et al. 2013). While incidental bycatch of this species
may still occur, they presumably go unreported or catches
may not be retained since they are protected in the UAE
(Jabado et al. 2014). Similarly, reports of C. melanopterus
from the Gulf are widespread, but few specimens have been
confirmed (Gubanov and Schleib 1980;Bishop2003). Moore
et al. (2011) suggested that this species may have been re-
placed by C. leiodon in shallow water habitats of the Gulf.
However, in the UAE, C. melanopterus is common around
many coastal and offshore islands (RWJ, personal observa-
tion) where fishing is prohibited, and the low number of
sharks (n=38) recorded in this study may not reflect their
abundance. Furthermore, as noted by Jabado et al. (2014),
most carpet shark species with low market value, such as
C. arabicum and S. fasciatum, are generally discarded at sea
and thus are presumably not accurately represented in land-
ings. This could also be due to fishing practices and the
positioning of fishing gear, which may preclude the capture
of demersal or bottom-associated species such as these. Final-
ly, it is possible that other, less abundant species or seasonal
migrants would have been documented if more frequent sam-
pling had been undertaken or if the study had focused on
certain remote areas where targeted shark fisheries were pres-
ent. For instance, the C. taurus in this study was reported
opportunistically when a fisherman showed the project inves-
tigator pictures of his catches on an offshore island in Abu
Dhabi (Jabado et al. 2013).
The presence of species documented in this study that had
not been previously reported from southern Gulf waters, in-
cluding C. amblyrhynchos and G. cuvier, may indicate that
they are either less abundant or migratory. For instance, the
C. leiodon specimens were recorded only in November and
December, suggesting that this species may be present in these
waters during limited times of the year (Moore et al. 2013). To
date, however, the only evidence of the occurrence of
N. acutidens was from a photograph in Saudi Arabia (Basson
et al. 1977). The collection of 41 individuals during the
present study suggests that this species is more common than
previously thought. Finally, the actual number of shark spe-
cies in the Gulf may be even higher, as the sighting of a
thresher shark, Alopias sp., was reported by a diver at an
offshore wreck in Dubai. It was recognized based on its
‘shark’appearance and its elongated tail (David Holdman,
pers. comm.), a characteristic feature in this family of sharks
(Compagno et al. 2005). While verification of this sighting is
not possible, it is important to note that thresher sharks have
been reported in the literature, and the remains of four caudal
vertebrae belonging to threshers have been documented at
archeological sites in Abu Dhabi (Beech 2004b). Furthermore,
both the pelagic thresher, Alopias pelagicus (Nakamura,
Mar Biodiv
1935), and the big eye thresher, A. superciliosus (Lowe,
1841), are present in Omani waters (Henderson et al. 2007).
Considering that the Gulf is regarded as a highly stressful
environment for many species, the total number of shark
species recorded from this study is high. Indeed, studies from
the Red Sea, an enclosed body of water considered a marine
biodiversity hotspot, have confirmed only 29 species of sharks
(Golani and Bogorodsky 2010; Spaet et al. 2011). Surveys
conducted in Omani waters have documented 36 shark spe-
cies from the Arabian Sea, while 34 species have been report-
ed in the Maldives (Anderson and Ahmed 1993; Henderson
and Reeve 2011). However, compared with other countries in
the broader Indian Ocean region such as India, which has
documented 66 shark species, and Sri Lanka with 61 species,
the species richness in the Gulf is significantly lower (Joseph
1999;Rajeetal.2002;Herath2012). This may be due to a
variety of reasons, including the diversity of fishing gear used
in other countries as well as exploited habitats. Indeed, in
countries that fish in the Gulf, operations are characterized
by artisanal fisheries limited to wooden dhows and fiberglass
dories using traditional gear (Carpenter et al. 1997), whereas
other countries in the region utilize a diversity of fishing
vessels that operate with a variety of gear at different depths
(Joseph 1999).
The limited bathymetry of the Gulf likely precludes habi-
tation by deepwater species such as the bramble shark,
Echinorhinus brucus (Bonnaterre, 1788), that has been docu-
mented in Oman, or even small species favoring deep waters,
such as the bigeye hound shark, Iago omanensis (Norman,
1939), that are commonly found in the Arabian Sea (Hender-
son et al. 2007; Javadzadeh et al. 2010; Henderson and Reeve
2011). The global deepwater chondrichthyan fauna, for exam-
ple, is highly biodiverse yet remains largely undocumented
(Kyne and Simpfendorfer 2007). Several studies have now
indicated that shark species richness can be affected by both
bottom-water temperature and depth, with distinctive fauna
characterized by spatial distribution of species (Menni et al.
2010; Guisande et al. 2013). Therefore, since the deepest
waters in the Gulf are close to the Strait of Hormuz, where
there is a lack of fisheries data and research, it is possible that
shark species not previously recorded for this basin may be
present, and that these could be subdivided based on different
variables such as depth and temperature.
Carcharhinidae was the dominant species (95.5 %) among
landings investigated in this study. It has been shown that this
family is very important in both commercial and artisanal
fisheries across the world, and species within the family
dominate shark landings in many tropical areas (Castillo-
Geniz et al. 1998;Compagnoetal.2005; Henderson et al.
2007;White2007; Last and Stevens 2009). The most abun-
dant species recorded in this study, C. sorrah and R. acutus,
are also widespread regionally, dominating landings in areas
where they occur (Krishnamoorthi and Jagadis 1986;
Anderson and Ahmed 1993;Bonfil2001; Capapé et al.
2006; Henderson et al. 2007;FAO2009;LastandStevens
2009; Moore et al. 2012a).There are few available historical
records of C. limbatus in the Gulf region, and it is not fre-
quently found in landings from Kuwait, Qatar, or Bahrain
(Moore et al. 2012a; Moore and Peirce 2013). However, it
represents one of the eight most abundant species in Omani
landings (Henderson et al. 2007), which is consistent with
findings in this study. Loxodon macrorhinus has been docu-
mented in Oman landings as the third most abundant, and in
Maldives, where it represented 70 % of sharks caught based
on a research survey (Anderson and Ahmed 1993). During the
first year of their study, Henderson et al. (2007) noted that
L. macrorhinus was absent from landings in Al Batinah, Al
Wusta, and Musandam, but subsequently became the most
abundant landed species in Musandam. In our study, individ-
uals were recorded from all sites and were most common in
RAK (comprising 62.8 % of landings), which is situated
adjacent to the Musandam Peninsula. However, they were
rare in Abu Dhabi (n = 8), and it is likely that the high number
of records from Abu Dhabi (155 individuals) reported by
Moore et al. (2012a), which lack information regarding their
place of capture, reflect the transport of sharks overland from
other areas in the UAE or Oman for sale at the market
(unpublished data). Reports of C. dussumieri suggest that this
species is widespread and abundant in the Gulf, especially in
Kuwait and Iran, although it is not frequently recorded in
Bahraini or Omani landings (Blegvad and Loppenthin 1944;
Basson et al. 1977; Gubanov and Schleib 1980; Henderson
et al. 2007;FAO2009; Moore et al. 2012a; Moore and Peirce
2013). Mustelus mosis has been reported in various publica-
tions (Blegvad and Loppenthin 1944; Basson et al. 1977;
Gubanov and Schleib 1980), but information regarding its
abundance remains scarce. Moore and Peirce (2013)notedit
as the second most abundant species from landings in Bahrain,
and while it was documented in Oman by Henderson et al.
(2007), no details were provided regarding its occurrence.
All species reported from Kuwait, Qatar, and Bahrain
landings were also present in UAE landings (Moore et al.
2012a; Moore and Peirce 2013). The lower number of species
recorded in northwestern Gulf surveys may be a result of the
limited temporal sampling there, which occurred only during
April. Indeed, even in the UAE, some species were recorded
only at specific times of the year, such as C. falciformis in the
autumn months. Furthermore, with the exception of the two
Chiloscyllium species, N. ferrugineus, and R. oligolinx, the
majority of species reported here were also documented in
Omani landings (Henderson and Reeve 2011).
Spatial and seasonal distribution
A total of 26 species of sharks were recorded in Sharjah, while
only 19 species were recorded in Abu Dhabi, and these two
Mar Biodiv
sites had the lowest species overlap. While these differences
are likely not due to fishing methods utilized, since similar
gear is used across the country, they may be explained by the
variability in fishing grounds used by fishermen in these two
emirates and differences in habitat and environmental condi-
tions in the two areas. Although Abu Dhabi waters include
some offshore islands with deeper waters, most of the western
inshore is characterized by shallow embayments with higher
water temperatures and salinities (EAD 2011). On the other
hand, fishermen in Sharjah largely utilize offshore and deeper
waters towards the northeastern UAE region, which are
supplied with oceanic water inflowing from the Arabian
Sea (Price 1993). Studies have shown that the richest areas
for fish fauna within the Gulf are closer to the Strait of
Hormuz, where waters are deeper (Price 1993). The simi-
larities in species recorded for Sharjah, RAK, and even
Dubai likely reflect the use of similar fishing grounds.
Landings of M. mosis, on the other hand, were notable in
RAK but less frequent in Dubai and Sharjah, potentially
indicating a difference in species behavior.
While there were some seasonal variations in the numberof
species caught, the overall dominant species did not change
throughout the sampling period. However, there was a shift in
seasonal dominance between C. sorrah and R. acutus,where
C. sorrah was more common during spring and summer,
while R. acutus was more abundant in autumn and winter
landings. All other species were caught in lower numbers
during the summer, which was also the season that yielded
the lowest number of landed species overall, comprising only
17.8 % of total landings. Studies on demersal teleost fish
species in the Gulf show patterns of distribution and abun-
dance that vary seasonally and among habitat types (Basson
et al. 1977; Shallard and Associates 2003). Grandcourt (2012)
suggested that this was likely due to higher water temperatures
during the summer and the lower volume of fishing activity at
that time of the year. In fact, it is believed that the reduced
abundance of reef fish during the summer is a result of the
movement of species to deeper and cooler waters (Shallard
and Associates 2003). Some studies have shown that the most
common species of sharks can change seasonally (Bizzarro
et al. 2009). Data from the artisanal shark fishery in Mexico
showed landings that were highly seasonal and that varied
among regions, which was attributed to the migratory behav-
ior of various species of sharks (Castillo-Geniz et al. 1998).
Similarly, landings in Oman showed marked differences
among seasons and across survey sites, also believed to be a
result of the migration patterns of different shark species
(Henderson et al. 2008). Lastly, seasonal differences in
landings may be due to variations in relative abundance
of shark species in local waters. Indeed, as fishermen
were found to be highly opportunistic, and as most areas
within UAE waters have been utilized for fishing, the
species composition of landings across seasons and
locations likely are a true reflection of local relative
abundance (Jabado et al. 2014).
With the exception of C. limbatus, the dominant species in
the UAE are relatively small sharks, measuring less than
1,500 mm L
T
, that commonly form large schools in inshore
waters (Compagno et al. 2005; Last and Stevens 2009). While
little is known about the behavior of M. mosis,itmostlikely
forms groups in inshore areas in a similar fashion to other
species of triakids known to be abundant in coastal waters
(Compagno et al. 2005). Likewise, C. limbatus, a larger shark
reaching over 2,500 mm L
T
, is known to prefer inshore areas
and is commonly found in large surface schools (Compagno
et al. 2005). This aggregating behavior and preference for
inshore waters may explain the particularly high abundance
of these species in landings. Similarly, the market dominance
of predominantly small-bodied sharks from a limited number
of species has been recorded in other areas. Data from Oman
have reported that the dominance of eight species among
landings (Henderson et al. 2007). Five species represented
64 % of landings in the northeastern Gulf (Moore et al.
2012a); three species were dominant in Iran (FAO 2009); 12
species were most abundant in Sri Lankan catches (Herath
2012);andfivespeciescomprisedupto90%ofshark
specimens recorded in Chinese markets (Lam and Sadovy
de Mitcheson 2011). In this study, while some species of
large-bodied sharks were found in landings, they were largely
either immature specimens (unpublished data), such as
C. limbatus, or species that did not contribute substantially
to landings, such as C. brevipinna and S. mokarran.
While little information is available on whether larger
sharks were more common at one time, fishermen have stated
that the size of sharks in the Gulf has greatly diminished
(Jabado et al. 2014). As such, it is possible that many larger
species have been overfished to some extent, and that the
fishery is now reliant on smaller sharks that are dominant in
landings. It is important to note that individual species may
have different levels of susceptibility or resilience to exploi-
tation (Stevens et al. 2000; Bonfil 2001). Small-bodied
carcharhinids such as R. acutus tend to grow fast, mature
early, have short life spans, and display aseasonal reproductive
cycles (Wourms 1977; Stevens and McLoughlin 1991). On
the other hand, larger sharks such as C. brevipinna mature
much later and exhibit slower growth rates, while typically
displaying seasonal breeding cycles and producing annual,
biennial, or triennial litters (Wourms 1977; Last and Stevens
2009). Thus the overall lifehistory traits ofsmall shark species
generally lead to higher biological productivity, making them
less susceptible to fishing pressure, which may explain their
dominance at various markets. Musick et al. (1993) noted that
overexploitation of large sharks in areas off southeastern
Africa and the northwest Atlantic could have led to the pro-
liferation of small-bodied sharks. A declining trend in the
number of large sharks and a shift in efforts towards smaller
Mar Biodiv
individuals have also been documented in Mexico, China, and
Madagascar, where species composition of landings for the
whole area has been affected (McVean et al. 2006;Bizzarro
et al. 2009;LamandSadovydeMitcheson2011). Henderson
et al. (2007) documented such a shift in the Omani shark
fishery, where in just a few years, larger sharks such as
C. limbatus and S. lewini were displaced by the smaller
L. macrorhinus and C. macloti.
A change in species composition or size of fished sharks
could have serious implications for the sustainability of a
fishery (Stevens et al. 2000). Furthermore, population studies
of coastal shark species have indicated that even a slight
increase in juvenile mortality can greatly impair the sustain-
ability of coastal shark fisheries (Cortes 1998). It is well
known that anthropogenic impacts such as overfishing and
habitat degradation have altered populations of sharks around
the world (Stevens et al. 2000). The risk to many species is
also believed to be depth-related, where species occupying
shallower waters are more accessible to fishing activities
(Dulvy et al. 2014). Considering the relatively small size and
shallow depth characteristics of the Gulf, as well as the in-
creasing anthropogenic disturbances that this entire basin is
facing, it is important to monitor shark catches in the UAE in
order to document changes in species and size composition of
shark landings.
Species identification
A complete and reliable taxonomic account of shark species is
the most crucial, albeit challenging, aspect of fishery sam-
pling, and is an integral component of effective fishery man-
agement, as it allows identification of species richness and
diversity (White and Last 2012). In many instances, molecular
methods such as the use of the COI gene sequence have
become important identification tools for distinguishing be-
tween closely related species (White and Last 2012). In most
cases here, morphologically identified species were congru-
ently matched in the BOLD and GenBank COI databases and
conspecific species clustered together in the NJ analysis.
However, some questions about specimen identification
remain.
The inability to assign C. arabicum to a species in either
database is due to the fact that a barcode for this species is not
available for comparison. Similarly, the lack of a match for
R. oligolinx in GenBank also indicates a lack of sequences for
this species within the database. The clustering of P. randalli
and C. macrostoma sequences that also matched P. tengi
(Chen, 1963), a species that has not been recorded from the
western Indian Ocean (Compagno et al. 2005), may be due to
a variety of reasons, including the possibility that these species
share haplotypes, or that there was misidentification in the
field, mislabeling errors for the samples, or misidentification
of species associated with COI sequences in the databases
(White and Last 2012).
The success of barcoding is dependent upon low levels of
sequence variation within species and much higher levels
between species (Holmes et al. 2009). As such, some closely
related species may not be easily identifiable despite their
morphological differences. In our study, the C. limbatus and
C. amblyrhynchoides species pair could not be convincingly
differentiated by barcoding. Ward et al. (2008)reportedlow
COI sequence divergence and low bootstrap support for these
species, and Moore et al. (2011)statedthattheCOIgenewas
barely distinguishable between them. Similar outcomes were
also reported for the closely related species C. plumbeus and
C. altimus (Springer, 1950), leading to the conclusion that the
COI barcode may not be suitable for discriminating among
some closely related shark species, and that an additional
marker with a higher rate of evolution would be necessary
(Ward et al. 2008).
It has been recommended that developing a voucher col-
lection is a necessity when undertaking genetic analysis in
order to resolve questions about specimen identification
(Ward et al. 2005). A collection could not be started in this
study because of limited resources and lack of storage facili-
ties necessary when dealing with large animals such as sharks.
Only one study has focused on developing a specimen and
barcode collection for fish species in the Gulf, which included
two shark species, C. macrostoma and M. mosis (Asgharian
et al. 2011). Therefore, it seems that to better understand the
evolution of species within the Gulf, a centralized facility
would be warranted.
Considerations for shark conservation
A number of species considered to be of global conservation
concern were recorded in this study, including C. limbatus,
C. dussumieri,C. falciformis,C. plumbeus,S. lewini, and
S. mokarran, which are listed either as threatened or Near
Threatened on the IUCN Red List (IUCN 2012). However,
because IUCN assessments generally lack information from
the Gulf, accurate data obtained locally are needed to deter-
mine which species here are most threatened. While data
collected in this study are not a clear indication of the status
of shark stocks in the UAE, they do provide a baseline that
should prove beneficial for effective future monitoring and
sustainable exploitation of targeted shark stocks. Results sug-
gest that there may be a depletion of larger shark species in
these waters, where there is a clear lack of species-specific
regional life history data and quantitative mortality
assessments.
While some laws for shark management already exist in the
UAE, they should be reexamined in light of the data gathered
from this study and before unmonitored catches further com-
promise the recovery of already-depleted stocks in the Gulf.
Mar Biodiv
Globally, the conservation of sharks has been confounded by
delayed responses regarding fishery restrictions, typically
resulting in the implementation of management strategies
following overexploitation of targeted shark populations (Ste-
vens et al. 2000). Although there is no baseline information
with which to compare the results from this study, all of the
data here and from interviews with Emirati fishermen indicate
that there is a high level of pressure on shark populations in
UAE Gulf waters (Jabado et al. 2014). In view of the life
history traits and the possible detrimental impacts of fishing
on many shark species, a precautionary approach to managing
these resources is warranted.
Acknowledgments We are grateful for the grant from the United Arab
Emirates University to Rima W. Jabado that supported this project. The
genetic analysis of the samples was supported by the Save Our Seas
Foundation. We are grateful to Kimberley Atwater for the laboratory
genetic work and to the volunteers who participated in the field surveys,
without whom this study would not have been possible.
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