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An Update on the Marine Turtle Status in the
Northeast Semporna Priority Conservation Area
WWF-Malaysia Semporna PCA
Project Report
December 2014
© WWF-Malaysia / Mazidi Abd Ghani
Copyright © 2014 WWF-Malaysia.
All rights reserved. No part of this publication may be reproduced,
Stored in a retrieval system, or transmitted in any form
or by any means, electronic, mechanical, photocopying,
recording, or otherwise, without the prior permission of
the copyright owner.
The opinions of the authors articulated in this
publication do not necessarily reflect those of
WWF-Malaysia.
Design and layout by Gavin Jolis and Kimberly Chung.
Technical editor: Monique Sumampouw, Sharifah Ruqaiyah
Suggested citation:
Jolis, Gavin. (2014). An Update on the Marine Turtle Status in the Northeast
Semporna Priority Conservation Area: WWF-Malaysia.
Perpustakaan Negara Malaysia Cataloguing-in-Publication Data
Jolis, Gavin, 1987-
An Update on the Marine Turtle Status in the Northeast Semporna
Priority Conservation Area / by Gavin Jolis.
ISBN 978-967-0237-35-0
1. Sea turtles--Conservation--Sabah--Semporna.
2. Sea turtles--Sabah--Semporna.
I. Title.
597.92809592153
Printed in Malaysia.
iii
An Update on the Marine Turtle Status in the
Northeast Semporna Priority Conservation Area
By
Gavin Jolis
Report Produced Under Project MA010411000
WWF-Malaysia Marine Programme
December 2014
iv
Table of Contents
Acronyms ............................................................................................................ v
Preface ................................................................................................................ vi
Acknowledgments ............................................................................................. vii
Executive Summary ......................................................................................... viii
Ringkasan Eksekutif .......................................................................................... ix
1. Introduction ..................................................................................................... 1
2. Study Objectives and Geographic Scope ........................................................ 3
2.1 Study objectives ............................................................................................. 3
2.2 Geographic scope .......................................................................................... 3
3. Literature Review ............................................................................................ 5
4. Methods and Materials ................................................................................... 7
4.1. Monitoring of nests, eggs and emerging hatchlings .................................... 7
4.2 Nesting turtle morphometric........................................................................ 8
4.3 Tagging .......................................................................................................... 9
4.4 Determining annual clutch frequency and internesting intervals ............. 10
4.5 Determining clutch size .............................................................................. 10
4.6 Incubation period and incubation success ................................................. 10
4.7 Determining reproductive output ............................................................... 11
4.8 Determining sources and magnitude of mortality ...................................... 11
4.9 Nesting beach and seagrass bed areas survey and assessment .................. 12
5. Results ............................................................................................................ 14
5.1 Nesting and interseasonal ecology ............................................................... 14
5.2 Population and re-nesting dynamics .......................................................... 20
5.3 Morphometrics and growth ........................................................................ 22
5.4 Reproductive output ................................................................................... 25
5.5. Nesting beaches identification and assessment ........................................ 30
5.6 Seagrass bed identification and assessment .............................................. 33
5.7 Sources and magnitude of mortality ........................................................... 41
6. Discussion ..................................................................................................... 49
7. Conclusion and Recommendations .............................................................. 56
8. References ..................................................................................................... 58
9. Appendices .................................................................................................... 64
9.1 Permit to conduct aerial mapping survey in Sabah issued by Chief
Minister’s Department of Sabah (Ref: JKM/HEDN&P 100-24/2/1/158/ (29))
........................................................................................................................... 64
9.2 Permit to take aerial photographs in Sabah issued by Land and Surveys
Department (LSC 4068.22.Vol.11). .................................................................. 67
9.3 Schedule of the monthly monitoring of nests and turtles .......................... 68
9.4 Aerial photos of seagrass beds and nesting beaches .................................. 69
9.5 Ground thruthing photos of seagrass beds ................................................ 84
9.6 Flight path of aerial survey ......................................................................... 87
v
Acronyms
CCLmin Minimum curved carapace length
CCW Curved carapace width
CITES Convention on International Trade in Endangered
Species of Wild Fauna and Flora
cm Centimetre
DNA Deoxyribonucleic acid
et al. And others
GPS Global Positioning System
ha hectares
IUCN World Conservation Union
km Kilometre
km2 Kilometre square
m Metre
mm Millimetre
mtDNA Mitochondrial deoxyribonucleic acid
MY(S) Malaysia (Sabah)
n Sample size
PCA Priority Conservation Area
pers. comm. Personal communication
R2 Correlation coefficient
RM Ringgit Malaysia
SD Standard deviation
SSME Sulu-Sulawesi Marine Ecoregion
SIMCA Sugud Islands Marine Conservation Area
TRACC Tropical Research and Conservation Centre
WWF World Wide Fund for Nature
x Mean
vi
Preface
Marine turtles have survived on earth for centuries. Mankind’s actions have
brought many populations of marine turtles to the brink of extinction. Turtles
have been used for food and other commodities either for their shell, meat,
oils, or leather. Recently turtles have become important for non-consumptive
uses such as tourism, education and research activities, and other gains.
Furthermore, turtles are unique components of complex ecological systems
where they maintain the balance of the marine ecosystem. Malaysia has
significant nesting populations, especially the green and hawksbill turtles.
Within the Semporna district in the state of Sabah, turtles can be found
nesting and foraging. Seeing the importance of these populations in the
district, turtle conservation efforts are being carried out by various agencies
and organisations including WW-Malaysia. This technical report will provide
the result of the habitats assessment and an update of the status of marine
turtles in the northeast islands of Semporna Priority Conservation Area which
will be beneficial for management of the species and the habitats involved.
vii
Acknowledgments
This project was funded by WWF-Netherlands, the Adessium Foundation, the
Hupkes Family in the Netherlands, and WWF-Malaysia.
The monitoring activity was conducted collaboratively with government
agencies, resort operators and conservation organisations which I am grateful
t0, namely:
Sabah Wildlife Department
The Reef Dive Resort
Pom-Pom Island Resort
Celebes Beach Resort
Wawasan Gunung Emas S/B, and
Tropical Research and Conservation Centre (TRACC)
viii
Executive Summary
Three-year records from 2011 to 2013 of green and hawksbill turtle nesting at
the northeast Semporna Priority Conservation Area (PCA) along with seagrass
beds and nesting beach assessments are described. This is a continuation to a
previous study by Jolis & Kassem (2011). The inconsistent beach patrolling
documented a total of 753 green and 88 hawksbill nests, with over 85 green
and 10 hawksbill turtles nested at Pom-Pom and Mataking with lack of
movement between the islands. There is an increase of documented nests
between present and previous studies suggesting an increase effort of patrols
rather than an increase in nesting trends. The inconsistency was due to lack of
patrollers, bad weather and security reasons.
For green turtles, adult females at Mataking and Pom-Pom islands averaged
96.9cm in minimum curved carapace length (CCLmin) and 88.2cm in curved
carapace width (CCW). Average clutch size was 87.3 eggs. Average nesting
frequency was 1.5 nests per female, per season with an average interval of 15.5
days between clutches. Nesting season is extended year-round, peaking in
August and a drop in January with individual nesting seasons averaged at only
36.2 days. Recapture rates are low (less than 6.0%). Remigration interval
averaged 3.1 years, with averaged CCLmin growth rates of 6.0 cm yr-1. A total
of 40,123 hatchlings were produced at Mataking, Pom-Pom, and Pandanan
islands. Hatchery incubation period at Mataking and Pom-Pom averaged 56.4
and 54.1 days, respectively. Hatchery hatching success rates averaged 78.6%
and 80.4% inclusive of nests that did not hatch at all, while emergence success
rate averaged 77.8 and 79.2%, respectively. Nesting was spread across six
hours of night time, with a peak between 2100 and 2300 hours majority
during mid-tides. 26 dead turtles were recorded and 101 nests were poached
by humans. For hawksbill turtles, adult females at Mataking and Pom-Pom
islands averaged 79.8cm in CCLmin and 72.2cm in CCW. Average clutch size
was 126.4 eggs. Nesting season extended year-round, peaking in April and
June then a drop in December. A total of 7,269 hatchlings were produced at
Mataking, Pom-Pom and Pandanan islands. Hatchery incubation period at
Mataking and Pom-Pom islands averaged 57.9 and 57.4 days, respectively.
Hatchery hatching success rates at Mataking and Pom-Pom islands averaged
70.9% and 78.6% inclusive of nests that did not hatch at all. The emergence
success rate averaged 69.9% and 77.4%, respectively. Nesting was spread
across six hours of night time, with a peak between 2100 and 2300 hours
majority during mid-tides. Four stranded dead turtles were recorded, and
three nests were poached by humans.
Turtles and their nests are threatened primarily by human poaching and
beach erosion. An illegal head-starting program used to be carried out at
Pandanan island. Loss of seagrass beds (0.3-3.1%) and nesting beaches (0.0-
0.7%) due to tourism development was calculated but found insignificant
despite causing light pollution. Tourism development will impact the habitats
and the increased priority of safety measures is deemed to increase in coming
years, which may affect the consistency of data collection. Minor terrestrial
predation by monitor lizards and ghost crabs threatens eggs or hatchlings, as
eggs are incubated in hatcheries.
ix
Ringkasan Eksekutif
Rekod persarangan penyu hijau dan sisik di Timur Laut Kawasan
Pemuliharaan Keutamaan Semporna selama tiga tahun dari 2011 dan 2013
dan keputusan penilaian rumput laut dan pantai pendaratan dihuraikan.
Kajian ini merupakan sambungan kepada kajian Jolis dan Kassem (2011).
Perondaan pantai secara tidak konsisten telah merekod 753 dan 88 sarang
penyu hijau dan sisik, dengan sekurang-kurangnya 85 dan 10 penyu betina
hijau dan sisik mendarat di Pulau-pulau Pom-Pom dan Mataking. Pergerakan
persarangan enyu betina di antara pulau adalah amat kurang. Peningkatan
persarangan penyu telah direkod di antara kedua-dua kajian. Hal ini mungkin
kerana peningkatan usaha perondaan daripada peningkatan haluan
persarangan.
Untuk penyu hijau, penyu dewasa betina di Mataking dan Pom-Pom
mempunyai panjang purata sebanyak 96.9cm dan lebar 88.2cm. Purata saiz
sarang adalah 87.3 telur. Bilangan persarangan seekor penyu betina dalam
satu musim adalah 1.5 sarang dengan purata 15.5 hari di antara sarang.
Musim persarangan adalah selama setahun, dengan puncak pada bulan Ogos
dan menurun pada bulan Januari dengan purata tempoh musim persarangan
mengikut individu adalah 36.2 hari. Kadar penangkapan penyu betina dewasa
yang ditanda kurang dari 6.0%. Purata tempoh persarangan antara musim
adalah 3.1 tahun, dengan kadar tumbesaran sebanyak 6.0cm tahun-1. 40,123
anak tetasan telah dihasilkan di Pulau Mataking, Pom-Pom dan Pandanan.
Purata tempoh pengeraman sarang di dalam pusat penetasan adalah 56.4 hari
di Mataking dan 54.1 hari di Pom-Pom. Purata kadar penetasan sarang dalam
pusat penetasan adalah 78.6% di Mataking dan 80.4% di Pom-Pom, ini
termasuklah sarang-sarang yang tidak menetas langsung. Purata kadar
kemunculan sarang adalah sebanyak 77.8% di Mataking dan 79.2% di Pom-
Pom. Persarangan adalah tersebar dalam 6 jam pada waktu malam dengan
puncak di antara 2100 dan 2300 jam kebanyakan pada waktu pertengahan air
pasang-surut. Sebanyak 26 penyu mati dan 101 sarang yang diburu oleh
manusia telah direkod.
Untuk penyu sisik, penyu dewasa betina di Mataking dan Pom-Pom
mempunyai panjang purata sebanyak 79.8cm dan lebar 72.2cm. Purata saiz
sarang adalah 126.4 telur. Musim persarangan adalah selama setahun, dengan
puncak pada bulan April dan Jun serta menurun pada bulan Disember. 7,269
anak tetasan telah dihasilkan di Mataking, Pom-Pom dan Pandanan. Purata
tempoh pengeraman sarang di dalam pusat penetasan adalah 57.9 hari di
Mataking dan 57.4 hari di Pom-Pom. Purata kadar penetasan sarang dalam
pusat penetasan adalah 70.9% di Mataking dan 78.6% di Pom-Pom, ini
termasuklah sarang-sarang yang tidak menetas langsung. Purata kadar
kemunculan sarang adalah sebanyak 69.9% di Mataking dan 77.4% di Pom-
Pom. Persarangan adalah tersebar dalam 6 jam pada waktu malam dengan
puncak di antara 2100 dan 2300 jam kebanyakan pada waktu pertengahan air
pasang-surut. Sebanyak 4 penyu mati dan 3 sarang yang diburu oleh manusia
telah direkod.
x
Penyu dan sarang mengalami beberapa ancaman terumatamya dari
pemburuan sarang oleh manusia dan hakisan pantai. Program kolam
intepretasi tanpa kebenaran telah diperhatikan di Pandanan. Pembangunan
di kawasan rumput laut (di antara 0.00-0.73%) dan pantai pendaratan (0.0-
3.70%) telah menyebabkan kehilangan kedua-dua habitat namun begitu kesan
yang dialami adalah rendah. Walau bagaimanapun, pembangunan tersebut
menyebabkan pencemaran lampu. Situasi keselamatan yang ketat dan
pembangunan pelancongan yang berterusan mungkin akan memberikan
kesan kepada pengumpulan data pada masa akan datang. Kadar pemburuan
anak tetasan dan telur penyu oleh pemangsa semula jadi seperti biawak dan
ketam adalah minima disebabkan operasi pusat penetasan penyu.
1
1. Introduction
Marine turtles are cold-blooded reptiles that dwell in tropical and subtropical
seas throughout the world. There are seven species of marine turtles in the
world. Government agencies and environmental organisations recognise
them as globally important and a flagship species for both local and regional
conservation. Marine turtles are important indicators of coastal and marine
habitats, such as seagrass beds, coral reefs and sandy beaches. The green
turtle (Chelonia mydas) crop seagrasses and algae, keeping them healthy; and
the hawksbill (Eretmochelys imbricata) feed mostly on spongers found in
crevices between corals. The eggs and hatchlings provide the sandy beaches
with vital nutrients and predators with food source. Marine turtles also
provide economic benefits to countries by attracting tourists to see or dive
with turtles. For centuries, the green and hawksbill turtles have been
harvested by man for their shell and meat, and their eggs have been collected
for food. Both species are currently listed as Endangered and Critically
Endangered in the Red Data Book of the World Conservation Union (IUCN)
and listed (along other remaining 5 species) under Appendix I in Convention
on International Trade in Endangered Species of Wild Fauna and Flora
(CITES).
At the southeast corner of the Malaysian Bornean state of Sabah, lies the
Semporna district and Semporna town. The town, at the eastern tip of the
Semporna Peninsula is the main trading town for more than 50 islands. The
district and its waters are recognised as a Globally Outstanding Priority
Conservation Area (PCA) within the Sulu-Sulawesi Marine Ecoregion (SSME),
at the apex of the Coral Triangle (Figure 1). The Semporna PCA has a high
coral, fishnd shrimp taxa richness that rivals the top spots in the Coral
Triangle, productivity of its marine habitats is high and it is frequently used as
a migratory pathway by many marine species including marine turtles
(Kassem et al., 2012). There is one existing marine protected area in the
district which covers 350km2 out of the approximately 7,680km2 of the PCA,
which is the Tun Sakaran Marine Park. The Sipadan Island’s waters are
proposed as a park and the intention to gazette was published in mid-2009.
These two parks are known to host nesting and foraging green and hawksbill
turtles.
Seeing the importance of marine turtles in the PCA, WWF-Malaysia through
the “Semporna PCA Project” initiated a turtle conservation strategy in 2009
and carried out an assessment between November 2009 and April 2010 to
create a baseline of marine turtle status in the northeast islands of the PCA.
The islands were Mataking, Pom-Pom, Kulapuan, Boheyan, Timba-Timba and
Pandanan. The assessment included analysis of nesting records from 2006 to
2010. Recommendations suggested and implemented by WWF-Malaysia in
collaboration with island communities and resort operators include nests
protection, long-term monitoring, education and awareness, and responsible
eco-tourism.
As follow up to the recommendations of the assessment, WWF-Malaysia
assessed the turtle habitats from July to October 2012 in the northeast islands
2
of Semporna PCA. This survey is the second assessment of the same area after
Jolis & Kassem (2011). The result obtained from this survey will be compared
to the previous study and will present any changes in nests, eggs and hatchling
numbers. It is seen that a rapid tourism development occurred in those
islands after 2010; hence WWF-Malaysia deemed it necessary to assess the
nesting beaches and seagrass beds as well.
This technical report will provide the result of the habitats assessment and an
update of the marine turtle status in the northeast islands of Semporna PCA
by drawing nesting records collected by WWF-Malaysia and stakeholders
from 2011 to 2013.
Figure 1: The Semporna PCA
3
2. Study Objectives and Geographic Scope
2.1 Study objectives
The objectives of the study are to:
Provide an update on the marine turtles status in the six northeast
islands of Semporna PCA drawing nesting records from 2011 to 2013,
and
Identify and assess the status of the nesting beaches and seagrass beds
in the area.
2.2 Geographic scope
As a continuation of the site chosen by Jolis & Kassem (2011), WWF-Malaysia
chose to survey the islands of northeast Semporna PCA (Table 1) (Figure 2).
The Semporna district and Semporna town are bounded on the west by the
districts of Kunak and Tawau, while to the north and south lays inlets of the
Sulawesi Sea, Darvel Bay and Cowie Bay respectively. Marine products are still
the mainstay of the local economy, as well as tourism. The northeast islands
within the district are located 30km northeast of Semporna (5°28’1.08”N,
116°59’33.24”E). There are villages ranging from 1,500 to 2,000 community
members consisting of Bajau, the nomadic Bajau Laut (or Sea Gypsies) and
Suluk in two islands. Resorts are found in the remaining islands.
Table 1: Islands of Northeast Semporna PCA.
Islands
Latitude
Longitude
Size (ha)
Inhabitants
Kulapuan
4°31’48.13”N
118°50’53.42”E
56.14
Resort and
about 500
community
(Bajau Laut
and Suluk)
Boheyan
4°28’19.44”N
118°56’10.28”E
20.82
200
community
(Bajaut Laut
and Suluk)
Pandanan
4°34’46.88”N
118°54’53.42”E
5.24
Resort (being
built)
Mataking*:
Mataking Kecil
Mataking Besar
4°35’23.34”N
4°34’36.70”N
118°56’44.04”E
118°56’55.52”E
1.73
23.54
Resort
Pom-Pom
4°35’45.20”N
118°51’53.31”E
35.90
Resort
Timba-Timba
4°33’19.81”N
118°55’15.45”E
2.00
Resort (being
built)
*Both islands are connected by a sand bar during low tide, and collectively
called Mataking Island (Sie, pers. comm.). Inhabitant data sourced from
Semporna district profile (2010).
4
The islands are made by coral cays (small, low-elevation, sandy island on the
surface of a coral reef) formed mainly from coral sands. Thorough description
of the islands can be found in a report by Jolis & Kassem (2011). The beaches
are fringed by halophytic vegetation including palm trees, shrubs and creeping
vegetation. Each island is surrounded by seagrass beds and coral reefs of
various types, species, abundance and coverage (Ho & Kassem, 2009; Ho et
al., 2012).
The wet season or the northeast monsoon occurs from December to January,
while the southeast monsoon is during June and July. The transition periods
bring variable wind patterns and rainfall (Wood, 1994). Tidal fluctuations are
semi diurnal and the tidal range varies between 1.2 and 2m (Wood, 1987).
Figure 2: Islands of the northeast Semporna PCA
5
3. Literature Review
The northeast Semporna PCA hosts three nesting turtle species; namely, the
green turtle (Chelonia mydas), hawksbill (Eretmochelys imbricata) and the
olive ridley (Lepidochelys olivacea) (Jolis & Kassem, 2011). The former two
species are predominant nesters while the latter has sporadic nestings. The six
islands in the northeast Semporna PCA namely Mataking, Pom-Pom,
Kulapuan, Boheyan, Timba-Timba and Pandanan islands have nesting
seasons that begin in March and extends through September. Annual nestings
range from six to 58 nests for green turtles and from five to 16 nests for
hawksbill turtles. Only one olive ridley nest was recorded in 2010 at Pandanan
Island. Detailed results of eggs incubated in hatcheries and hatchings can be
found in a report by Jolis & Kassem (2011).
In addition, green and hawksbill turtles are also found to nest at the nearby
island of Sipadan (Mortimer, 1991). The Sipadan island supports a large
density of green turtles, second only to the Turtle Islands Park (Palaniappan,
2001). At Sipadan island, most nestings were by green turtles (more than 900
nests per year) and the hawksbill was an uncommon nester (less than 40 nests
per year) (Basintal, 2002). The island’s peak season for green turtles is July to
December while for hawksbill is from January to June. Palaniappan (2001)
documented other sites in the Semporna district with potential nestings. The
Turtle Islands Park and Sugud Islands Marine Conservation Area (SIMCA) are
important nesting sites for green turtles in Sabah (Basintal, 2001). Gulisaan
island of the Turtle Islands Park provides a nesting habitat to the largest
hawksbill turtle population in the entire Southeast Asian region (Chan et al.,
1999).
Mortimer (1991) studied green population dynamics of resident turtles at
Sipadan island and showed that adult turtles were most abundant. However, a
recent study by Tinsung et al. (2011) indicates juveniles were most abundant.
The juvenile green turtles in Sipadan island consist of mix stocks, drawn
primarily from Sabah Turtle Islands and Philippines Turtle Islands, followed
by Australia, Micronesia, Papua New Guinea and Indonesia, confirming
Sipadan island as one of the important feeding grounds in Malaysia apart
from nestings (Joseph & Chong, 2014).
The turtle population in the northeast Semporna PCA is under increasing
pressure from discarded plastic bags, domestic and natural predators, nesting
beach erosion, removal of coastal vegetation, coastal development, fish
bombing, egg and turtle poaching, incidental captures, boat propellers and
conflicts with seaweed farmers (Jolis & Kassem, 2011). More than 10 years
ago, poaching of eggs from nests for sale, seawater intrusion to nests, and
resort development were threats to Sipadan island (Mortimer, 1991). Within
the Tun Sakaran Marine Park, Mantabuan Island is identified as a nesting site
and hunting of adult turtles for consumption is identified as a possible threat
(Wood, 1981; 2001). Recently, the discoveries of more than 60 turtle carcasses
at Kudat and five floating dead green turtles in Semporna have alarmed
government agencies and conservationists (Anon, 2014b & 2014c).
6
In Sabah, there are two government bodies overseeing the management of
turtles, which are Sabah Parks (for marine protected areas under their
jurisdiction) and the Sabah Wildlife Department. Marine turtles are
legislatively protected under the Parks Enactment 1984 and Wildlife
Conservation Enactment 1997. The green and hawksbill turtles are listed
under their legislation as Totally Protected Animals. Under Section 41 of the
Wildlife Conservation Enactment 1997, offenders risk being fined up to RM
50,000 or five years jail, or both upon conviction. Nonetheless, turtle eggs are
still being sold illegally in Sabah with recent news reporting turtle egg seizures
in Sandakan (Anon, 2012 & 2014a).
Turtles’ nesting beaches and feeding grounds are also majorly threatened
primarily by humans through coastal development. These habitats are
important to provide opportunities for female turtles to nest on the beaches,
or turtles to forage and feed on seagrass beds. There are no published reports
on quantifiable seagrass distributions per islands around Semporna. Reports
on species and seagrass coverage at limited and selected sites were done
through the Seagrass-Watch protocol method by Ho et al. (2011). There are
eight species of seagrass in Semporna PCA, and of these, seven species were
documented in the northeast islands which are; Enhalus acoroides, Thalassia
hemprichii, Halophila ovalis, Cymodocea rotundata, Cymodocea serrulata,
Halodule pinifolia and Halodule uninervis.The former five species were the
most frequently spotted species. The Thalassia hemprichii is a major part of
green turtles’ diet (Bjorndal, 1997) and is assumed to be the reason for the
high number of this species found in Sipadan island (Lelian et al., 2008).
7
4. Methods and Materials
4.1. Monitoring of nests, eggs and emerging hatchlings
Monthly monitoring by WWF-
Malaysia and Sabah Wildlife
Department (Figure 3)
commenced on 14 May 2011 and
continued until 5 December 2012
in the six islands. The monitoring
was designed to be a 1-day trip
from 0900 to 1700 hrs or as
overnight stays of up to 3 days. A
team of five persons monitored
the beach during the day to
search for turtle tracks or
disinterred nests indicating
presence of emergence. In light of
the safety measures taken by
WWF-Malaysia and Sabah Wildlife Department, monitoring was halted from
January to December 2013.
In addition, night monitoring by
resort operators (The Reef Dive
Resort, Pom-Pom Island Resort,
and Wawasan Gunung Emas S/B)
and non-profit organisation
Tropical Research and
Conservation Centre (TRACC)
(Figure 4) commenced on 1
January 2011 and continued until
31 December 2013 in Mataking,
Pom-Pom and Pandanan islands.
A team of two to five personnel
monitored the beaches for nests
and turtles. Monitoring
commenced after nightfall (from 1900 to 2000 and sometimes extended until
0200). Occasionally, frequent but irregular monitoring during the day was
also carried out to check for daytime nestings.
Both monthly and nightly monitoring were based on the technique described
by Schroeder & Murphy (1999). During monitoring, the teams:
Recorded nesting and non-nesting emergences,
Recorded nesting emergences location with Global Positioning System
(GPS),
Recorded nesting time,
Recorded tidal height,
Recorded morphometric measurements of the nesting females,
Figure 3: Staff from WWF-Malaysia and
Sabah Wildlife Department doing their
monitoring
Figure 4: Staff from the Reef Dive Resort
doing their monitoring
© WWF-Malaysia / Mazidi Abd Ghani
© WWF-Malaysia / Mazidi Abd Ghani
8
Tagged the nesting females,
Recorded total counts of eggs, and
Transferred all nests to hatcheries.
Nesting beaches on each island were divided into sectors of 200m per sector.
For islands with established sectors of various lengths that is Pom-Pom Island
through the resort, the present study adopted the said sectors for analysis.
Sectors were formed in alphabetic order, starting from “A” at the beginning on
the south side and ran clockwise around the western side to the north and east
of each island, with an exception to Mataking Kecil and Timba-Timba islands
due to its very narrow beach.
Eggs were collected either during
oviposition or shortly thereafter
and transferred to hatcheries
(Figure 5) where they were
reburied following Mortimer
(1999). Weight and
measurement of eggs were not
taken. Each nest was surrounded
by a mesh screen (3mm mesh
size) to contain emerging
hatchlings. Incubation
temperatures were not taken.
Once hatched, hatchlings were
documented and released, nests
were excavated, and the contents were examined and recorded after two days
of the first emergence. Hatchlings weight and measurements were not taken.
4.2 Nesting turtle morphometric
Nesting females were measured on beaches to monitor growth rates. Adult
females were measured following Bolten (1999). Measurements were taken
with a flexible fiberglass tape measure (± 0.1cm) including (Figure 6):
Minimum Curved Carapace Length (CCLmin) – measured over the
curve of the carapace along the midline from the anterior point at the
midline of the nuchal scute to the posterior tip of the supracaudal
scutes, and
Curved Carapace Width (CCW) – measured over the curve of the
carapace perpendicular to the midline across the widest portion of the
carapace.
© WWF-Malaysia / Mazidi Abd Ghani
Figure 5: The hatchery on Mataking Island
9
Figure 6: Minimum curved carapace length and width (Pilcher, 2004).
Each measurement was recorded only one time for each nesting female.
Measurement accuracy was calculated from repeated measurements of the
same individual within the same nesting season.
4.3 Tagging
Nesting females were tagged with
stainless steel Monel No. 49 BJ
(Period of 2012 and 2013) and
Inconel tags No. 681 MY(S) (Period
of 2011 and 2012) (National Band
and Tag Co.) at a proximal
location, in between the flattened
scutes of the posterior edge of both
front flippers following Balazs
(1999) (Figure 7). Double tagging
was implemented to minimize
problem of tag loss. A 0.5 – 1.0 cm
gap was left between the trailing
edge of the flipper and the rear
edge of the tag to allow for growth
in the coming years. The tags contains return address and contact numbers.
Turtles were tagged and measured when they had completed covering the nest
cavity or as they return to the sea after nesting, regardless of whether the
nesting attempt was successful or not. Remigratory intervals were calculated
from the last successful nest of one season to the first successful nest of the
following season (Pilcher & Ali, 1999).
The tagging programme on nesting females started in 2009 and onwards by
The Reef Dive Resort at Mataking island, while Pom-Pom Island Resort
started at Pom-Pom island in 2012. WWF-Malaysia and Sabah Wildlife
Department participation in the tagging programme started in 2011, hence the
present study will only analyse tagged nesting females from 2011 to 2013.
Figure 7: Location of tag
© George Balazs
10
4.4 Determining annual clutch frequency and internesting
intervals
Two methods were used to estimate clutch frequency of individuals. The
observed clutch frequency was obtained by dividing the number of clutches
laid by tagged females by the number of tagged females, and the estimated
mean clutch frequency was calculated as the observed clutch frequency
corrected for the missing nests that had not been observed (Johnson &
Ehrhart, 1996; Broderick et al., 2002; Garnier et al., 2012). Corrections were
based on the assumptions that for internesting intervals > 20 days and < 60
days one clutch had been missed, and for internesting intervals > 60 days two
clutches had been missed.
Internesting intervals were calculated as the number of days between a
successful nesting and subsequent nesting attempt, after excluding intervals <
7 days, which were considered to represent aborted nesting events (Bourjea et
al., 2007). Calculations also exclude turtles nesting more than 30 days after
first sighting as the turtle might have nested during this period but was not
observed.
4.5 Determining clutch size
Clutch size is the number of eggs laid into the nest, excluding yolkless eggs,
and was determined by counting eggs at oviposition (the time of laying) or, if
the clutch was transferred, counting was accomplished at reburial (Miller,
1999).
4.6 Incubation period and incubation success
Incubation period was recorded as the number of days from when the eggs
were laid until the date of when the first hatchling emerged from the nest
(Niethammer et al., 1997).
After incubation and hatchling emergence, nests were excavated to determine
the following:
E = Emerged Number of hatchlings leaving or have departed
from nest,
S = Shells Number of empty shells – only those more than
50% complete were counted,
L = Live in nest Live hatchlings left in the nest,
D = Dead in nest Dead hatchlings left in the nest,
UD = Undeveloped Unhatched eggs with no obvious embryo,
11
UH = Unhatched Unhatched eggs with obvious embryo (excluding
UHT),
UHT = Unhatched term Unhatched apparently full term embryo in shell or
pipped eggs, and
P = Depredated Eggs that have been predated on (open; nearly
complete shells with egg residue inside)
Hatching success and emergence successes were established to assess
incubation success. Hatching success was the number of hatchlings that hatch
out of their egg shell (equals the number of empty egg shells in the nest), while
emergence success was the number of hatchlings that reach the beach surface
(equals the number of empty egg shells minus the number of live and dead
hatchlings remaining in the nest chamber) (Miller, 1999). Both parameters
were computed based on the below formulas:
Hatching success (%) = #shells __ x 100
#shells + #UD + #UH + #UHT + #P
Emergence success (%) = #shells – (#L + #D) __ x 100
#shells + #UD + #UH + #UHT + #P
4.7 Determining reproductive output
Total reproductive output (O) based on Pilcher (2004) was computed based
on the below formula:
O = T x R x C x I
Where:
T = estimated number of turtles
R = average clutch frequency
C = average clutch size
I = average incubation
4.8 Determining sources and magnitude of mortality
Actual and potential sources of mortality at all life stages for marine turtles
were determined for eggs and hatchlings through the monthly and nightly
monitoring. The mortality of adults was estimated through investigations of
dead turtles stranded on the beach, drifted on the water surface or submerged
underwater reported to WWF-Malaysia, Sabah Wildlife Department, local
communities and resort operators.
12
4.9 Nesting beach and seagrass bed areas survey and assessment
The nesting beaches and seagrass
bed areas were first identified
through satellite imageries and aerial
surveys in 1 October 2012.
The aerial survey employed a
technique described by Rasheed et
al. (2001), and Pilcher (2010) and
were adapted for the survey area.
Flights were conducted using a Bell
206 Jet Ranger helicopter owned by
Sabah Air Aviation Sdn. Bhd. (Figure
8). Date of survey was selected based on suitable low tides when seagrass
meadows were exposed or covered by less than 0.5m of water. Survey was not
conducted during peak nesting season. Flight for monitoring was flown during
morning at no higher than 300 feet, travelling at approximately 70 knots or
slower where required. Surveys were conducted along randomized transect
lines (typically oriented in a NW to SE). Flight paths were created from
satellite imagery data using ARCGIS 9.3. Transect lines were uploaded to a
Garmin GPS276C which was used by the captain for navigation. Observer 1
and 2 stationed on the left and right side of the helicopter respectively took
photographs of seagrass beds on each island, while Observer 3 counted
sighted swimming turtles and turtle tracks on the beach for the duration of the
flight. Permits to fly to conduct aerial mapping survey in Sabah were obtained
through Chief Minister’s Department of Sabah (Ref: JKM/HEDN&P 100-
24/2/1/158/(29)) (See Appendices 1), and permission to take aerial
photographs were obtained through Land and Surveys Department (LSC
4068.22.Vol.11) (See Appendices 2).
Spot checks (ground-truthing visits) at the
nesting beaches and seagrass beds were
conducted during October 2012 after the aerial
survey. Spot checks were conducted to further
verify the spotted and identified seagrass beds
in the satellite images and aerial survey. The
nesting beaches were characterised through
detailed surveys by foot, during which, human
impacts and its extent and condition were
assessed. The seagrass bed areas were
characterized by selecting points (Pom-Pom, 10
points; Mataking, 40 points; Pandanan, 25
points; Timba-Timba, 35 points; Boheyan, 34
points; and Kulapuan, 39 points) depending on
the size of the seagrass bed per island and in a
fixed line circling the island and each point
were visited. Surveys were conducted 1) by
walking through the seagrass bed and sand, 2)
kayaks and 3) small boats for safe verification
Figure 8: Aerial survey
Figure 9: Seagrass spot
checking
© WWF-Malaysia / Mazidi
Abd Ghani
© WWF-Malaysia
13
(Figures 9 & 10).
Boundaries and area of seagrass bed
were determined by using satellite
imagery. Satellite imagery recorded
on 3 April 2012 and 6 May 2009 with
sensor of WorldView-2 was applied
to guide the estimation of seagrass
area extant. Satellite imagery were
purchased from Digital Globe with
varies size of area of interest, 3-59
km2. Software ArcGIS version 9.3
and ERDAS IMAGINE 11 were used
to produce reliable maps by using
GIS layers as base map to plot decimal degree.
Figure 10: Seagrass spot checking
© WWF-Malaysia / Mazidi Abd Ghani
14
5. Results
5.1 Nesting and interseasonal ecology
Nesting volumes – 15 monthly monitoring trips documented a total of 103
green and 4 hawksbill nesting emergences on the northeast islands (Tables 2
& 3). Of these, 13 trips were day-trips while the remaining two were overnight
trip up to 3 days each (See Appendix 9.3 for the schedule).
Table 2: Number of green turtle nesting emergences on the northeast islands,
2011–2012 (non-nesting emergences given in parentheses).
Year
Mataking
Pom-
Pom
Timba-
Timba
Boheyan
Kulapuan
Pandanan
Total
2011
2
1
1
1
4
0
9
2012
8 (1)
4 (1)
12
39 (4)
30 (1)
1
94 (7)
Table 3: Number of hawksbill turtle nesting emergences on the northeast
islands, 2011–2012 (non-nesting emergences given in parentheses).
Year
Mataking
Pom-
Pom
Timba-
Timba
Boheyan
Kulapuan
Pandanan
Total
2011
2
0
0
0
0
0
2
2012
1
0
0
2 (1)
1
0
4 (1)
Approximately 1,095 days of nightly monitoring trips between 2011 and 2013
documented a total of 666 green and 85 hawksbill nesting emergences on
Mataking, Pom-Pom and Pandanan islands (Tables 4 & 5).
Table 4: Number of green turtle nesting emergences in Mataking, Pom-Pom
and Pandanan islands, 2011–2013 (non-nesting emergences given in
parentheses).
Year
Mataking
Pom-Pom
Pandanan
Total
2011
124 (1)
46
27
197 (1)
2012
178 (4)
72 (50)
26 (3)
276 (57)
2013
120
72 (1)
1
193 (1)
Table 5: Number of hawksbill turtle nesting emergences in Mataking, Pom-
Pom and Pandanan islands, 2011–2013 (non-nesting emergences given in
parentheses).
Year
Mataking
Pom-Pom
Pandanan
Total
2011
25
5
3
33
2012
33
7 (3)
3
43 (3)
2013
6
3
0
9
All trips collectively documented a total of 753 green and 88 hawksbill nesting
emergences on the northeast islands inclusive of in situ nests of 6 green and 2
hawksbill nests (Tables 6 & 7).
15
Table 6: Number of green turtle nesting emergences on the northeast islands,
2011–2013 (non-nesting emergences given in parentheses).
Year
Mataking
Pom-
Pom
Timba-
Timba
Boheyan
Kulapuan
Pandanan
Total
2011
124 (1)
46
1
1
4
27
203 (1)
2012
178 (4)
72 (50)
12
39 (4)
30 (1)
26 (3)
357 (62)
2013
120
72 (1)
0
0
0
1
193 (1)
Table 7: Number of hawksbill turtle nesting emergences on the northeast
islands, 2011–2013 (non-nesting emergences given in parentheses).
Year
Mataking
Pom-
Pom
Timba-
Timba
Boheyan
Kulapuan
Pandanan
Total
2011
25
5
0
0
0
3
33
2012
33
7 (3)
0
2 (1)
1
3
46 (4)
2013
6
3
0
0
0
0
9
Nesting procedure – The nesting
procedure observed turtles that
emerged at night (occasionally by
day) and crawled up to a suitable
nesting area. The body pit was
shallow, and excavated primarily
using the front flippers.
Subsequently an egg chamber was
dug using the rear flippers, into
which the eggs were laid, in groups
of one to four. After a brief pause,
the nests were reburied by
compacting moist sand over the
eggs using their rear flippers,
followed by loose, dry sand thrown backward over the nest by their front
flippers (Figures 11 & 12). After a variable time covering the nest, the female
headed directly back down to the water.
Nesting season – Green and
hawksbill turtles nest on the
northeast islands year round. Green
nesting peaked in August and
decreased in January (Figure 13).
Though low hawksbill nesting
continues year round, most nesting
occurs from April to July with peaks
in April and June and lowest
nesting frequency occurred in
December (Figure 14).
© Pom-Pom Island Resort / Melissa
Mangalis Mangalis
Figure 11: Green turtle nesting
Figure 12: Hawksbill turtle nesting
© Pom-Pom Island Resort / Melissa Mangalis
16
Figure 13: Monthly green nesting frequency on the northeast islands, 2011-
2013. Symbols represent mean values, squares represent the standard
deviation, and bars represent the range.
Figure 14: Monthly hawksbill nesting frequency on the northeast islands,
2011-2013. Symbols represent mean values, squares represent the standard
deviation, and bars represent the range.
17
Nesting timing – The majority (87.3%) of green nesting took place at night.
The nesting began at around 1900 hr, peaking between 2100 and 2300 hrs.
Only 27.8% of green turtles chose to nest at high tide, when the land distance
to suitable nesting sites is shortest, with the majority (53.5%) nesting during
mid- (receding or advancing) tides (Figure 15). Hawksbill nesting were
moderate during daylight hours (41.9%) and generally began at around 1900
hrs, peaking between 2100 and 2300 hrs, and gradually decreasing to 0200,
before peaking again at 0600 hr. 38.7% of these turtles nested between 2100
hrs and midnight. These turtles emerged predominantly (67.7%) during mid-
(receding or advancing) tides while 21% chose to nest at high tide (Figure 16).
0
5
10
15
20
25
30
35
40
45
50
910 11 12 13 14 15 16 17 18 19 20 21 22 23 0 1 2 3 4 5 6 7 8
Nesting frequency
Time (24h)
Low
Medium
High
Figure 15: Green turtles nesting occurrences in relation to time and tidal
height
18
0
1
2
3
4
5
6
7
8
9
10
910 11 12 13 14 15 16 17 18 19 20 21 22 23 0 1 2 3 4 5 6 7 8
Nesting frequency
Time (24h)
Low
Medium
High
Figure 16: Hawksbill nesting occurrences in relation to time and tidal height.
Internesting intervals – Calculated in 31 cases, the green turtle nesting
indicated an interval of 15.5 days (SD = 5.30, range: 8-27). Classified into 1st,
2nd, 3rd, 4th and 5th renesting occurrence, the internesting intervals were 15.1
(SD = 4.1; n = 15), 17.6 (SD = 6.3, n = 9), 17.0 (SD = 6.7, n = 3), 11.0 (SD = 1.0,
n = 2) and 11.5 days (SD = 0.5, n = 2). The modal observed internesting
interval was 13 days (Figure 17). Internesting intervals for hawksbill could not
be calculated due to limited data.
Length of nesting season – The length of nesting seasons were calculated
individually for 18 green turtles, excluding turtles that nested only once.
Among these, the nesting season lasted an average of 36.2 days (SD = 20.1;
range = 11-73). Over 77.6% were accomplished during 10-50 day nesting
periods (Figure 18). Length of nesting seasons for hawksbill turtle could not
be calculated due to limited data.
19
Figure 17: Internesting intervals between successful nesting attempts for
green turtles on Pom-Pom and Mataking islands, 2011-2013.
0
1
2
3
4
5
6
7
10 20 30 40 50 60 70
Frequency
Nesting season (days)
Figure 18: Individual season lengths for green turtle nesting on Pom-Pom and
Mataking islands.
1st interval
x = 15.1
2nd interval
x = 17.6
3rd interval
x = 17.0
4th interval
x = 11.0
5th interval
x = 17.0
20
5.2 Population and renesting dynamics
Number of tagged females – A total of 85 green and 10 hawksbill turtles were
tagged between 2011 and 2013 (Table 8), and only 3 recaptured green were
recorded (Table 9). However, it was informed that the patrolling efforts were
inconsistent between 2011 and 2013, and it was estimated that not 100% of
the nesting turtles were tagged.
Table 8: Number of green and hawksbill nesting females on Mataking and
Pom-Pom islands, 2011 – 2013 (No tagging on Pom-Pom island in 2011).
Year
Green
Hawksbill
Mataking
Pom-
Pom
Total
Mataking
Pom-
Pom
Total
2011
15
-
15
4
-
4
2012
28
23
51
2
3
5
2013
8
11
19
0
1
1
Table 9: Recapture of green and hawksbill nesting turtles since 2009.
Year
Green
Hawksbill
New
Recap
Total
New
Recap
Total
2009
18
0
18
5
0
5
2010
24
0
24
6
0
6
2011
15
0
15
4
0
4
2012
51
1
52
5
0
5
2013
19
2
21
1
0
1
Total
127
3
130
21
0
21
Recapture rates – Rates for green turtles are less than 6.0% in any year, with
the highest incidents of recaptures being 5.0% of individuals tagged in 2009
returning in 2012 and 2013 (Table 10). No recaptured hawksbill turtles
recorded.
Table 10: Recapture of green turtles.
Year
Number
of
tagged
Recaptures of tagged individuals. Percentage in ()
2009
2010
2011
2012
2013
Total
2009
20
0 (0)
0 (0)
1 (5.0)
1 (5.0)
2 (10.0)
2010
23
0 (0)
0 (0)
1 (4.3)
1 (4.3)
2011
15
0 (0)
0 (0)
0 (0)
2012
51
0 (0)
0 (0)
Remigration interval – The interval was recorded for 3 individuals, and
averaged 3.1 years (SD = 211.31, range = 2.8–3.8).
On 20th July 2012, a green turtle with measurements of CCLmin 84cm and
CCW 79cm tagged with PH1609G was found in attempt to nest on Pom-Pom
island. Investigation on the turtle made by WWF-Malaysia reached the key
21
agencies from the Philippines. The green turtle was first encountered on 22nd
March 2012, and again on 23rd May 2012, at Baguan island, Philippines Turtle
Islands Park, 300km north of Semporna where she was tagged PH1608G and
PH1609G for right and left front flipper respectively (Ramoso, pers. comm.).
The turtle travelled roughly more than 300km to Pom-Pom from the Baguan
islands.
22
5.3 Morphometrics and growth
Measurements – Adult minimum curved carapace length and width were
recorded for 79 green females nesting between 2011 and 2013. The average
CCLmin was 96.9cm (SD = 5.99, range = 71.0–110.5). Average CCW was
88.2cm (SD = 6.08, range = 60.0–99.0) (Table 11). Data accuracy was
considered to be moderately reliable with an average error of 2.6cm among
repeated measurements of the same individuals within a season (SD = 3.24,
range = 1.0-18.0).
Table 11: Summary of morphometric data for adult female green turtles at
northeast islands. Measurements recorded in centimetre.
2011
2012
2013
Total
CCLmin
x
94.7
97.3
97.6
96.9
SD
7.07
5.72
5.25
5.99
Min
71.0
85.0
88.0
71.0
Max
102.5
110.5
106.0
110.5
n
15
46
18
79
CCW
x
85.5
87.8
91.5
88.2
SD
8.36
5.20
4.19
6.08
Min
60.0
75.0
86.0
60.0
Max
90.7
99.0
98.0
99.0
n
15
46
18
79
Distribution of adult female sizes were found to be normal whereby 63.2% of
the population were within the 95 to 103 cm size class, with a small number of
recruits and older age size class (Figure 19).
Adult CCLmin and CCW were recorded for nine hawksbill females nesting
between 2011 and 2013. The average CCLmin was 79.8cm (SD = 4.83, range =
72.5-86.0). Average CCW was 72.2cm (SD = 7.20, range = 60.5-82.5) (Table
12). Data accuracy was not calculated due to limited data in the difference of
measurement.
Table 12: Summary of morphometric data for adult female hawksbill turtles at
northeast islands. Measurements recorded in centimetre.
2011
2012
2013
Total
CCLmin
x
80.0
79.4
81
79.8
SD
3.62
6.63
-
4.83
Min
73.0
72.5
-
72.5
Max
83.8
86.0
-
86.0
n
4
4
1
9
CCW
x
69.5
75.8
69.0
72.2
SD
0.91
10.4
-
7.20
Min
69.0
60.5
-
60.5
Max
71.1
82.5
-
82.5
n
4
4
1
9
23
0
2
4
6
8
10
12
71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 101 103 105 107 109 111
Frequency
Curved Carapace Length (cm)
Figure 19: Size class distribution of green nesting females at Pom-Pom and
Mataking islands.
Figure 20: Size class distribution of hawksbill nesting females at Pom-Pom
and Mataking islands.
24
Due to limited data, the distribution of adult hawksbill female sizes was
inconclusive (Figure 20).
Growth rates – Rates were measured for two green turtles, averaged 6.0 cm
yr-1 (CCLmin) (SD = 3.89, range = 0.5-6.0) and 3.5 cm yr-1 (CCW) (SD = 0.71,
range = 3.0-4.0). These figures exclude one green turtle that has a reduction
of length in CCW that may due to inconsistency of measurement taken by the
team.
25
5.4 Reproductive output
Number of eggs recorded – A total of 56,629 eggs from 638 green turtle nests
and 10,527 eggs from 85 hawksbill turtle nests were recorded (Tables 13 & 14).
Table 13: Number of green turtle eggs at Mataking, Pom-Pom and Pandanan
islands, 2011-2013 (Number of eggs were not recorded on Pandanan island in
2o13).
Year
Mataking
Pom-Pom
Pandanan
Total
2011
10,140
3,860
2,013
16,013
2012
15,907
5,330
1,114
22,351
2013
11,247
7,028
-
18,275
Table 14: Number of hawksbill turtle eggs at Mataking, Pom-Pom and
Pandanan islands, 2011-2013 (Number of eggs were not recorded on
Pandanan island in 2o13).
Year
Mataking
Pom-Pom
Pandanan
Total
2011
3,169
735
275
4,179
2012
4,573
768
153
5,494
2013
530
324
-
854
Clutch size – From 583 green turtle nests, clutch size averaged 87.3 eggs (SD =
24.50, range = 24-188), and 85 hawksbill nests averaged 126.4 eggs (SD =
39.00, range = 33-203) (Table 15). Although patrollers were previously
documented to have taken some eggs for personal consumption (recording
only the number of remaining eggs actually transferred to the hatchery), this
practice has been gradually ceased out through strict monitoring by resorts
(Abdullah, pers. comm.). With the caveat that this practise may have
occasionally affected the recorded clutch size, and in addition to the low clutch
sample size, this may result with inaccurate estimate of average clutch size.
Table 15: Clutch size of green and hawksbill turtles, 2011-2013.
2011
2012
2013
Total
Green
x
83.4
84.6
93.7
87.3
SD
23.56
24.07
24.66
24.50
Min
24
27
25
24
Max
153
162
188
188
n
192
196
195
583
Hawksbill
x
126.6
132.9
94.9
126.4
SD
37.8
38.56
32.90
39.00
Min
59
33
41
33
Max
203
192
151
203
n
33
43
9
85
Green clutch size was found to not correlate with minimum curved carapace
length (R2 = 0.484).This result is similar to hawksbills (R2 = 0.154).
26
Clutch frequency – Green turtles on Mataking island nested at an average of
1.5 nests in a season (SD = 1.19, n = 54), ranging from one to seven nests per
season; irrespective of the turtles’ status as a neophyte (possible first time
nester) or remigrant (Table 16), at nesting frequencies of once (77.3%), twice
(9.1%), three (2.3%), four (6.8%), five (2.3%) and seven times (2.3%).
Table 16: Months of night-time monitoring, number of adult female green
turtle tagged, number of clutches laid by tagged females, observed clutch
frequency and estimated mean clutch frequency ±SD on Mataking island,
2011-2013. SD = Standard deviation.
2011
2012
2013
Total
Months with night
patrols
January to
December
January to
December
January to
December
Number of nesting
females tagged
15
29
10
54
Number of clutches laid
by tagged females (%)
19 (15.4%)
45 (25.6%)
10 (8.3%)
74 (17.7%)
Observed clutch
frequency
1.3
1.6
1.0
1.4
Estimated mean clutch
frequency ± SD (range)
1.2 ± 0.41
(1-2)
1.8 ± 1.55
(1-7)
1.0 (1)
1.5 ± 1.19
(1-7)
Clutch frequency for green turtles on Pom-Pom island averaged 1.5 nests
within a season (SD = 1.24, n = 35) ranging from one to five nests per season,
irrespective of the turtle’s status as a neophyte or remigrant (Table 17), at
nesting frequencies of once (80.0%), twice (5.7%), three (2.3%), four (2.3%)
and five times (8.6%).
Table 17: Months of night-time monitoring, number of adult female green
turtle tagged, number of clutches laid by tagged females, observed clutch
frequency and estimated mean clutch frequency ±SD on Pom-Pom island,
2011-2013. SD = Standard deviation.
2012
2013
Total
Months with night patrols
January to
December
January to
December
Number of nesting females tagged
24
11
35
Number of clutches laid by tagged
females (%)
34 (47.2%)
15 (20.8%)
49 (68.1%)
Observed clutch frequency
1.4
1.4
1.4
Estimated mean clutch frequency ±
SD (range)
1.6 ± 1.35
(1-5)
1.5 ± 1.03
(1-4)
1.5 ± 1.24
(1-5)
Clutch frequency for hawksbill turtle on Mataking and Pom-Pom islands could
not be calculated due to limited data on renesting occurrence.
If we consider each green female deposit with the respective mean clutch
frequencies, the nesting population on Mataking island for 2011, 2012 and
2013 were 103, 99 and 120 turtles, respectively. For Pom-Pom island, the
27
green nesting populations for 2012 and 2013 were 45 and 48 turtles,
respectively.
Number of hatchlings recorded – A total of 40,123 hatchlings from 50,903
green turtle eggs, while 7,269 hatchlings from 10,076 hawksbill turtle eggs
were recorded (Tables 18 & 19).
Table 18: Number of green turtle hatchlings at Mataking, Pom-Pom and
Pandanan islands, 2011-2013 (Number of hatchlings were not recorded on
Pandanan island in 2o13).
Year
Mataking
Pom-Pom
Pandanan
Total
2011
8,653
3,164
97
11,914
2012
12,082
3,981
-
16,063
2013
8,099
4,033
-
12,132
Table 19: Number of hawksbill turtle hatchlings at Mataking, Pom-Pom and
Pandanan islands, 2011-2013 (Number of hatchlings were not recorded on
Pandanan island in 2o13).
Year
Mataking
Pom-Pom
Pandanan
Total
2011
2,197
606
0
2,803
2012
3,524
789
-
4,313
2013
14
139
-
153
Incubation period – Incubation period was recorded for 414 green and 60
hawksbill hatchery clutches incubated in Mataking island and averaged 56.4
days (SD = 4.14, range = 46-75), and 57.9 days (SD = 2.61, range = 51-66)
respectively. For Pom-Pom island, incubation period was recorded for 143
green and 14 hawksbill hatchery clutches and averaged 54.1 days (SD = 6.26,
range = 43-81), and 57.4 days (SD = 8.40, range = 51-85) respectively (Table
20).
Table 20: Incubation period for green and hawksbill hatchery clutches on
Mataking and Pom-Pom islands, 2011-2013.
Islands
Species
2011
2012
2013
Total
Mataking
Green
x
57.7
55.3
56.6
56.4
SD
3.57
3.39
5.13
4.14
Min
47
48
46
46
Max
69
69
75
75
n
123
170
121
414
Hawksbill
x
58.6
57.6
56.0
57.9
SD
2.27
2.51
5.29
2.61
Min
55
51
50
51
Max
66
62
60
66
n
25
32
3
60
Pom-Pom
Green
x
52.4
54.4
55.4
54.1
SD
2.79
5.58
8.52
6.26
Min
48
47
43
43
Max
59
79
81
81
28
n
42
53
48
143
Hawksbill
x
53.8
56.3
65.3
57.4
SD
1.30
3.39
17.21
8.40
Min
52
51
53
51
Max
55
61
85
85
n
5
6
3
14
Emergence success – Average emergence success for 414 green and 60
hawksbill hatchery clutches of which one or more hatchlings emerged in
Mataking island were 77.8% (SD = 23.03, range = 0.0-100.0) and 69.9% (SD
= 26.6, range = 0.0-100.0) respectively. For Pom-Pom island, average
emergence success for 149 green and 13 hawksbill hatchery clutches were
79.2% (SD = 18.36, range = 0.0-100.0) and 77.4% (SD = 19.36, range = 35.2-
97.2) respectively (Table 21).
Table 21: Emergence success for green and hawksbill hatchery clutches on
Mataking and Pom-Pom islands, 2011-2013.
Islands
Species
2011
2012
2013
Total
Mataking
Green
x
84.2
79.1
69.3
77.8
SD
17.13
21.14
27.9
23.03
Min
0.0
0.0
0.0
0.0
Max
100.0
100.0
100.0
100.0
n
123
170
121
414
Hawksbill
x
71.1
75.1
4.3
69.9
SD
25.64
19.80
7.51
26.6
Min
0.0
23.5
0.0
0.0
Max
100.0
97.3
13.0
100.0
n
25
32
3
60
Pom-Pom
Green
x
82.7
73.7
81.9
79.2
SD
12.75
22.65
16.11
18.36
Min
35.8
0.0
24.0
0.0
Max
96.7
98.0
100.0
100.0
n
42
54
53
149
Hawksbill
X
81.9
77.7
65.5
77.4
SD
11.78
18.57
42.78
19.36
Min
69.2
44.5
35.2
35.2
Max
95.8
97.2
95.7
97.2
n
5
6
2
13
Hatching success – Out of the available nests (green = 414, hawksbill = 60),
2.42% of green nest and 5% of hawksbill nest did not hatch at all. The
inclusion of these failed nests resulted in an overall hatchery hatching success
of 78.6% for green, while 70.9% for hawksbill on Mataking island. The
hatchery hatching success on Pom-Pom island was 80.4% and 78.6% for green
and hawksbill nests respectively. These figures include one green nest (0.7%)
that did not hatch at all (Table 22).
29
Table 22: Hatching success for green and hawksbill hatchery clutches on
Mataking and Pom-Pom Islands, 2011-2013.
Islands
Species
2011
2012
2013
Total
Mataking
Green
x
85.1
79.5
70.9
78.6
SD
17.22
21.22
27.70
22.91
Min
0.0
0.0
0.0
0.0
Max
100.0
100.0
100.0
100.0
n
123
170
121
414
Hawksbill
x
71.4
76.7
4.3
70.9
SD
25.57
19.90
7.51
26.82
Min
0.0
23.5
0.0
0.0
Max
100.0
97.7
13.0
100.0
n
25
32
3
60
Pom-Pom
Green
x
82.7
76.4
82.7
80.4
SD
12.75
21.85
16.34
17.88
Min
35.8
0.0
24.0
0.0
Max
96.7
100.0
100.0
100.0
n
42
54
51
147
Hawksbill
x
82.0
79.0
68.9
78.6
SD
11.92
18.38
39.39
18.39
Min
69.2
44.5
41.0
41.0
Max
96.3
97.2
96.7
97.2
n
5
6
2
13
Total reproductive output – Considering Mataking island as the concrete data
from one island, data collected in this survey period were combined and
extrapolated to indicate a number of nesting parameters. Other islands have
very limited data on hatchling numbers thus were not chosen for total
reproductive output.
For annual output, the 2011 nest volume was used as example. The total
number of green nests at northeast islands was 203. Assuming the average
number of nests per turtle is 1.2 (as at Mataking); the number of turtles using
northeast islands beaches is approximately 169
1
. If the average number of eggs
per nest is 83.4 (as at Mataking), the total number of eggs is 14,094
2
.
Assuming 85.1% hatchery hatching success rate (as at Mataking); the total
production of hatchlings would be 11,993
3
. For the 2011 to 2013 period output,
the total number of green nests at northeast islands was 753. Assuming the
average number of nests per turtle is 1.5 (as at Mataking); the number of
turtles using northeast islands beaches is approximately 502
4
across the 3
years. If the average number eggs per nest is 87.3 (as at Mataking), the total
number of eggs is 65,737
5
. Assuming a 78.6% hatchery hatching success rate
(as at Mataking); the total production of hatchlings would be 51,669
6
.
1
203 nests / 1.2 = 169 turtles
2
203 nests x 83.4 eggs = 14,094
3
14,094 x 85.1% = 11,993
4
753 nests /1.5 = 502 turtles
5
753 nests x 87.3 eggs = 65,737
6
65,737 eggs x 78.6% = 51,669
30
5.5. Nesting beaches identification and assessment
The majority of the nesting beaches were found along each of the islands
totalling to 15.8km and 147.66ha (Table 23).
Table 23: Nesting beaches of northeast islands.
Islands
Length of
nesting beach
(km)
Number of
sectors
Hectares (ha)
Mataking
Besar
2.9
15
13.71 (18.57%)
Kecil
0.5
2*
2.45 (3.32%)
Pom-Pom
2.3
6*
11.53 (15.62%)
Pandanan
1.8
9
6.61 (8.95%)
Timba-Timba
1.7
9
6.03 (8.17%)
Boheyan
2.8
14
14.24 (19.29%)
Kulapuan
3.8
19
19.25 (26.07%)
* Length varies
The most important nesting site in the northeast Semporna islands was
deemed to be Mataking island (inclusive of Mataking Kecil and Mataking
Besar), based upon combination of available nesting data and actual
monitoring trips during this period and informed opinions of university
researchers and government agencies.
At Pom-Pom island, the beach was mostly comprised of fine-grained sand
supporting halophytic vegetation. The nesting beach was 2.5km and 9-52m
wide. Nesting were concentrated in Sector D (n = 51) of the beach on the
northern side of the island (Figure 23). Infrastructure within Pom-Pom island
included two resorts with jetties and chalets scattered from the west to the
south of the island, and a police base in the middle. A 230m seawall was seen
on Sector A.
Out of 34, two green turtles (5.9%) displayed true nest site fixity, while one
turtle (3.0%) nest at more than one zone on Pom-Pom island (returned to
within 700m of its original nest location). Nest site fixity could not be
calculated for other islands due to lack of data. Green turtles favoured the
northern (Sector D) and eastern (Sector B) sides of the island while using the
other beaches less frequently. Hawksbill turtles favoured the eastern (Sector
B) side of the island (Table 24).
Table 24: Green and hawksbill nesting distribution on Pom-Pom island in
2011 to 2013.
Species
Year
A
B
C
D
E
F
Green
2011
6
4
5
10
3
6
2012
0
7
3
10
5
2
2013
2
29
7
30
3
3
Hawksbill
2011
0
3
0
0
0
1
2012
0
0
1
1
0
1
2013
0
1
0
0
2
0
31
The beach of Kulapuan island also comprised of fine-grained sands
supporting halophytic vegetation. The nesting beach length was 3.8km, being
the longest with a width of 9-21m. The beach is home to settlements of 500
Bajau Laut and Suluk community members, with houses on stilts and boats of
various sizes docked on the beaches at the south with chalets and jetty built on
the north. A police base was next to the settlements. Nesting was concentrated
in Sector J (n = 11) of the beach on the northern side of the island. No nesting
was documented from the beaches on the western side of the island (Sectors A
to G). Sector T is characterised with mangrove-like trees extending 0.8km
inward into the island (Figure 24).
The beach of Pandanan island extended in length of 1.8km with width of
13-21m. The beach comprised of fine-grained sands supporting halophytic
vegetation including few coconut trees. Rocky shore only exposed during low
tide observed in Sector B with mangrove-tree like vegetation. Nesting was
concentrated in Sector D (n = 8) of the beach on the northern side of the
island; Sector G (n = 8) of the beach on the western side, and Sector H (n=8)
of the beach on the southern side of the island (Figure 25). Erosion was
observed predominantly on the north, the worst among all islands. No large
village settlements and resort infrastructures were observed, except for an
army base with helipad in the middle of the island were seen. There was
information about plans for a high-end resort to be built in the coming year on
the island. Only one of the renesting greens on Pandanan island was found on
Mataking Besar during the survey period (distance in between is 3.52km).
Timba-Timba island has a nesting beach with a length of 1.7km and width
of 9-14m, supporting halophytic vegetation with creeping plants.
Infrastructures were only a 125m jetty and small house. We were informed
there was a plan to build a high-end resort similar to Pandanan in the coming
three years. Several sectors contain erosion which may be due to seasonal
winds and waves. Nesting were concentrated in Sector E (n = 7) of the beach
on the northern side of the island (Figure 26).
Connecting to Timba-Timba through a lagoon, the beach of Boheyan island
was 2.8km and 4-10m wide supporting halophytic vegetation, which is home
to Water monitors. The beach is also home to settlements of 200 Bajau Laut
and Suluk community members, with houses on stilts and boats of various
sizes docked on the beaches at the north. Village settlements were divided into
two, which are Kampung Abdul Muhi and Kampung Roni on either sides of
the island. Mangrove-like trees were seen on some of the sectors but sparse.
Rocky shore was predominant on the north. An army base is located on the
south where nesting was concentrated in Sector B (n = 22) (Figure 27).
Finally, Mataking Besar has a nesting beach with a length of 2.9km and
width of 13-20m. The beach comprised of fine-grained sands, supporting
halophytic vegetation including coconut trees, which is home to several Water
monitors and Coconut crabs. Rocky shores at several sites were exposed
during low tides. Situated at the north-eastern extreme, and in the path of
predominant current patterns, the beach also accumulated a high amount of
driftwood and solid wastes. Infrastructures include chalets and resort jetties,
an army and police base with a helipad on the north. Erosion of beaches were
32
seen in several sectors especially those at the most south of the island.
Observation of seasonal erosion on certain sectors especially near the resort’s
dive centre was noted (Habirah, pers. comm.). Number of nesting increased
from the northern end of the island to the centre of the island. Nesting was
concentrated in Sector F (n = 25) of the beach on the eastern side of the island
(Figure 26). High tides restricted access to several sectors especially located at
the south. Connecting to Mataking Besar Island through a 0.7km sand bar
during low tide, the narrow Mataking Kecil has a nesting beach length of
0.5km with width of 12-21m, supporting halophytic vegetation. The beach
length was the shortest among all beaches. No infrastructures were observed
but plans are underway for building resorts. The beach also accumulated a
high amount of driftwood and other solid wastes. Nesting was concentrated in
Sector A (n = 24) followed closely in Sector B (n = 12) (Figure 28). The green
(70.1%) favoured Mataking Besar whereas hawksbill turtles (62%) favoured
Mataking Kecil (Table 25).
Table 25: Green and hawksbill turtles nesting distribution at Mataking Besar
and Kecil, 2011-2013.
Species
Islands
2011
2012
2013
Total
Green
Mataking Besar
94
122
75
291
Mataking Kecil
26
58
40
124
Hawksbill
Mataking Besar
11
12
1
24
Mataking Kecil
14
21
4
39
33
5.6 Seagrass bed identification and assessment
Seagrass was present at 55% of ground truth points examined between 11 and
16 October 2012 resulting approximately 1491.39 hectares (ha) of seagrass
mapped in the intertidal and shallow subtidal waters surrounding all islands.
All seagrass meadows were located on the fringing reef platforms. Three types
of seagrass meadow patchiness categories were found; namely, the isolated
seagrass patches, aggregated seagrass patches and continuous seagrass cover.
2.33% of the seagrass meadows
surrounding northeast islands
were present within the
boundaries of Pom-Pom island.
34.71 ha of seagrass were mapped
on 11 October 2012 (Figure 23).
Seagrass meadows were found less
than 2m deep and consisted of at
least three species in the same
area. Some to none isolated
patches were seen underneath
jetties and chalets. 15 green turtles
of various sizes (juvenile to adults)
were seen swimming, with one
personal observation with two adult green turtles feeding on seagrass off Pom-
Pom Island Resort’s jetty (Figure 21).
30.34% of seagrass meadows were present within the boundaries of
Kulapuan island. 149.08 ha of seagrass were mapped in the island on 16
October 2012 (Figure 24). Approximately half of the seagrass meadows in the
island were of continuous cover and located on large intertidal / shallow
subtidal reef platforms. Seagrass meadows were found less than 3m deep and
consisted of at least two species in the same area. One adult green turtle was
seen swimming at Kulapuan.
Approximately 2.27% of the seagrass meadows surrounding northeast islands
were present within the boundaries of Pandanan island. 33.82 ha of
seagrass were mapped on 13 October 2012 (Figure 25). Seagrass meadows
were found less than 2m deep and consisted of at least three species in the
same area. Some to none isolated patches were seen underneath jetties. 19
green turtles of various sizes (juvenile to adults) were seen swimming.
Figure 21: Green turtle feeding at Pom-
Pom Island
© WWF-Malaysia / Mazidi Abd Ghani
34
Connecting Timba-Timba and
Boheyan is a lagoon that is up to
5km wide. Seagrass meadows were
present on the edge of lagoon but
towards mid-lagoon, seagrass was
not seen. Being the greatest area of
seagrass meadows surrounding
northeast islands, Timba-Timba
and Boheyan islands with 77.75%
of the seagrass meadows
surrounding northeast islands was
present within the islands’
boundary. 1159.59 ha of seagrass
were mapped in the island on 14 and
15 October 2012 (Figures 26 & 27). Seagrass meadows were found less than 2-
3m deep and consisted of at least two species in the same area. On the edge of
Boheyan beach, seagrass meadows were seen in aggregation patches followed
by continuous cover. Some to none isolated patches were seen underneath
jetties. 19 green turtles of various sizes (juvenile to adults) were seen
swimming at both islands each especially at sites near the lagoon (Figure 22).
7.66% of the seagrass meadows surrounding northeast islands were present
within the boundaries of Mataking Kecil and Besar. 114.20 ha of seagrass
were mapped on 12 October 2012 (Figure 28). Seagrass meadows were found
less than 3m deep and consisted of at least two species in the same area. Some
to none isolated patches were seen underneath jetties. 32 green turtles of
various sizes (juvenile to adults) were seen swimming.
The maps created show the amount of nests observed per zone and the
location and distribution of the seagrass beds. There is no relationship
between the location sizes of the nesting beaches to the seagrass beds.
Figure 22: Green turtle feeding at
Timba-Timba
© WWF-Malaysia / Gavin Jolis
35
Figure 23: Seagrass and nesting spatial distribution at Pom-Pom Island
36
Figure 24: Seagrass and nesting spatial distribution at Kulapuan Island
37
Figure 25: Seagrass and nesting spatial distribution at Pandanan Island
38
Figure 26: Seagrass and nesting spatial distribution at Timba-Timba Island
39
Figure 27: Seagrass and nesting spatial distribution at Boheyan Island
40
Figure 28: Seagrass and nesting spatial distribution at Mataking Island
41
5.7 Sources and magnitude of mortality
Based on stranding records between 2011 and 2012, 26 green turtle carcasses
were documented. The average CCLmin ranged from 62.0 to 94.0cm, while
CCW was 56.0 to 89.0cm (n = 9), with length range of 91-100cm being the
most measured (Table 26, Figure 29). Of these, five green turtles had cracks
on its shell indicating boat propeller strikes. The highest number of carcasses
was documented on June with seven turtles (26.9%) (Figure 30).
Four hawksbill turtle carcasses were documented and only one measurement
was taken, which was a female with CCLmin 68.0cm and CCW 61.0cm. One of
those turtles was found dead with no physical injuries, next to destroyed reefs,
signs of blast fishing.
Table 26: Carapace measurement of green turtle carcasses. Measurements
recorded in centimetre.
CCLmin
CCW
Sex
x
SD
Range
n
x
SD
Range
n
Male
94.0
-
-
1
89.0
-
-
1
Female
83.6
14.77
61.5-92.0
4
75.5
12.4
58.0-87.0
4
Unknown
62.0
21.40
39.5-91.0
4
56.0
19.21
37.5-83.0
4
0
1
2
3
4
5
30-40 41-50 51-60 61-70 71-80 81-90 91-100
Frequency
Curved Carapace Length (cm)
Figure 29: Size composition of green turtle carcasses on the northeast
islands, 2011-2012.
42
Figure 30: Monthly occurrence of green turtle carcasses on the northeast
islands, 2011-2012.
From available records, an adult male green turtle carcass (CCLmin 94 cm)
was found on 3rd May 2012 at Mataking Island and was observed to have
existing Sabah Parks’ tags, which were MY(S)40593 and MY(S)40954 on the
left and right front flippers respectively. Further investigation revealed the
turtle was captured and tagged at Sipadan Island waters on 8th August 2010 as
part of Universiti Malaysia Sabah’s Sea Turtle Diet study project (Figure 31).
Figure 31: The adult male green turtle carcass found on 3 May 2012 at
Mataking Island was observed to have existing Sabah Parks’ tags.
101 green and three hawksbill turtle nests were deemed poached or
depredated. No predated or poached nests were documented in 2013 (Tables
27 & 28). Disturbed nests were recorded when water monitors were found
excavating the nests or nests were disinterred with egg residues trailed by the
water monitors’ footprints. Poached nests were recorded when eggs were
© The Reef Dive Resort
© The Reef Dive Resort
43
found to be missing from nests with signs of human footprints surrounding
the event. It is unknown if the eggs collected were brought to Semporna town
for sale even though egg selling at Semporna market exists in small scale
(Anon, 2014d). It was informed that the Bajau Laut does not consume turtle
eggs but rather, sells these eggs to the Bajau communities.
Table 27: Poached or predated green turtle nests, 2011-2013.
Year
Mataking
Pom-
Pom
Timba-
Timba
Boheyan
Kulapuan
Pandanan
Total
2011
1
1
1
1
3
0
7
2012
0
13
12
38
30
0
94
2013
0
0
0
0
0
0
0
Table 28: Poached or predated hawksbill turtle nests, 2011-2013.
Year
Mataking
Pom-
Pom
Timba-
Timba
Boheyan
Kulapuan
Pandanan
Total
2011
0
0
0
0
0
0
0
2012
0
0
0
3
0
0
3
2013
0
0
0
0
0
0
0
The team of Pom-Pom Island Resort shared an incident in 2012 when two
humans were seen to run away when they were spotted. It was later revealed
that the two individuals were stealing green turtle eggs from a nest.
Furthermore, there were two cases where the patrollers found a single egg in a
nest, which concluded that the eggs were poached as well (Mangalis, pers.
comm.). During an early morning monthly monitoring trip on Pom-Pom
Island in 2012, a green turtle nest was found with turtle tracks leading to a
nest and body pit; a nesting indication . However, the nest was later identified
to be poached when a few holes and egg shell were found on the sand surface.
Further investigation by digging a hole revealed that the eggs were missing.
No incidents of fisherman or suspicious human searching for eggs were noted.
It was informed that eggs were also collected in Boheyan and Kulapuan for
local consumption; however, adult turtle meat is not eaten.
Natural predators such as the monitor lizards (Varanus salvator) on
Mataking and Boheyan Islands, and the ghost crabs (Ocypode spp.) were seen
on all islands (Figure 32). However, the predation of water monitors which
prey on eggs and hatchlings have been mostly eliminated through the use of
the hatchery. Wild nests that are not collected by the team are occasionally
observed disinterred by monitor lizards (estimated to number 5-9 in Mataking
from personal observation) or poached by humans. Offshore, a number of fish
species patrol the fringing reef and are likely predators to swimming
hatchlings. These fish species have not been identified. Little or no aerial
predation exists in the near shore area. No predation by mice and rats was
observed. Predation of nesting females were undetermined as scars and
missing flippers were not recorded, and no land predation was noted on
adults.
44
Figure 32: A juvenile monitor lizard on Mataking Island, and footprints seen
on Boheyan Island.
It was informed by several resort personnel that 1-2 green Turtles at Pom-Pom
Island were found to have growth around its eyes and neck (Yazid; Mangalis,
pers. comm.). No photos were taken during observation. This could indicate
growth on healing wounds or tumour growth of Fibropapillomatosis (FP). FP
is a skin disease first described in green turtles over 70 years ago, and now
encountered more frequently. FP is characterised by multiple skin tumours,
from small to large, both external and internal, and can become life-
threatening when the tumour interferes with swimming, vision and breathing
of the turtle, or the physiology of the afflicted organs (Aguirre & Lutz, 2004).
Rearing of turtles or head-starting was also observed. The head-starting
programme was firstly documented in November 2011, where green and
hawksbill turtle hatchlings were reared in a nylon cage at shallow waters near
Pandanan beach, which were later demolished in early February 2012. During
a monitoring trip in March 2012, two ponds made from cement concrete
bricks were built and 54 green and 21 hawksbill hatchlings of various sizes
were later found on both ponds in April 2012. Green and hawksbill turtles are
protected under the Wildlife Conservation Enactment 1997, listed under
Scheduled 1, Totally Protected Species, which means rearing turtles in Sabah,
is discouraged and requires permit or permission from the Sabah Wildlife
Department. The head-starting programme at Pandanan Island is operated by
resort staff is owned by a high-level politician based in Tawau. A verbal
warning was given to the staff by the Wildlife Department in May 2012 to
demolish the ponds or apply for a permit as it is operating illegally (Figure
33).
© WWF-Malaysia / Gavin Jolis
© WWF-Malaysia / Gavin Jolis
45
Figure 33: Head-starting program at Pandanan Island
© WWF-Malaysia / Gavin Jolis
© WWF-Malaysia / Gavin Jolis
The head-starting nylon cage at
Pandanan Island (November 2011)
About 100 green and hawksbill
turtle hatchlings found within the
cage (November 2011)
© WWF-Malaysia / Gavin Jolis
© WWF-Malaysia / Gavin Jolis
The cage was later found to be
demolished (February 2012)
Two ponds made of concrete
bricks were observed to be built
(March 2012)
© WWF-Malaysia / Gavin Jolis
© WWF-Malaysia / Janice Antonio
54 green hatchlings were found
swimming on one of the ponds
(April 2012)
A green hatchling taken from one of
the ponds. This hatchling is
estimated to be 3 months old (June
2012)
46
Figure 34: Sector F of Pandanan Island, on August 2010 and February 2012.
Erosion of beaches was seen on several sectors of the islands, predominantly
in Mataking, Pom-Pom and Pandanan island. The erosion resulted in several
abandoned turtle nesting attempts (Figure 34).
Tourism development on the nesting beaches and seagrass beds were
observed at Mataking, Pom-Pom and Kulapuan Island, while it was informed
that plans to develop resorts are underway for Timba-Timba and Pandanan
Island. Chalets were built on several nesting beaches and jetties of various
lengths were built on top of seagrass beds. Mataking Kecil and Pandanan
Island were cleared off vegetation to give way for further resort development
(Figure 35). A seawall on Sector A of Pom-Pom Island prevents turtle nestings
(Figure 36).
Figure 35: A newly-built Kulapuan Island Resort at Kulapuan Island in April
2012, and vegetation cleared to make way for chalets and restaurants at
Mataking Kecil Island in June 2012.
© WWF-Malaysia / Gavin Jolis
© WWF-Malaysia / Fredyanna Tinsung
© WWF-Malaysia / Mazidi Abd Ghani
© WWF-Malaysia / Gavin Jolis
August 2010
February 2012
47
Figure 36: Jetty and seawall at Pom-Pom Island.
The loss of nesting beaches was observed. Mataking Besar has the highest loss
(3.70%) and Mataking Kecil has the lowest (0.00%) (Table 29).
Table 29: Comparison of nesting beaches with impacts of inappropriate
development on the beach
Islands
Available nesting
beaches (%)
Nesting beaches
loss to
inappropriate
development (%)
Mataking
Besar
96.30
3.70
Kecil
100.00
0.00
Pom-Pom
98.00
2.00
Pandanan
99.14
0.86
Timba-Timba
99.74
0.26
Boheyan
98.53
1.47
Kulapuan
97.13
2.87
Average
98.40
1.60
The loss of seagrass beds was also observed. Pom-Pom has the highest loss
(0.73%) and Mataking, Timba-Timba and Boheyan have the lowest (0.0%)
(Table 30).
Table 30: Comparison of seagrass beds with impacts of inappropriate
development on the seagrasses.
Islands
Available seagrass
beds (%)
Seagrass beds loss to
inappropriate
development (%)
Mataking (Inclusive of
Mataking Besar and Kecil)
100.00
0.00
Pom-Pom
99.27
0.73
Pandanan
99.99
0.01
Timba-Timba & Boheyan
100.00
0.00
Kulapuan
99.95
0.05
Average
99.84
1.16
© WWF-Malaysia / Lavernita Bingku
© WWF-Malaysia / Gavin Jolis
48
Walkway lanes and chalets lamps were seen on Pom-Pom and Mataking
Island. It was informed that yellow lights with varying intensity were emitted.
It was further informed that more lights were installed in 2013 as instructed
by enforcement personnels to enhance security of tourists on those islands as
a result of the Lahad Datu standoff and kidnapping cases in that same year
(Figure 37 & 38).
Figure 37: Lamps at Mataking Island.
Figure 38: Lamps at Pom-Pom Island.
© WWF-Malaysia / Gavin Jolis
© WWF-Malaysia / Rhena Ismail
© WWF-Malaysia / Gavin Jolis
© WWF-Malaysia / Gavin Jolis
49
6. Discussion
This survey is the second assessment of the status of marine turtles in the
northeast islands of Semporna PCA after Jolis & Kassem (2011). The result
obtained from this survey will be compared to the previous study and will
present any changes in nests, eggs and hatchlings numbers. Nonetheless, this
survey include detailed assessment on the nesting and interseasonal ecology,
population and renesting dynamics, morphometric and growth, the
reproductive output as well as seagrass distribution, which was not covered in
the previous study.
The northeast islands can hold to a minimum of 160 nesting green turtles
producing more than 14,000 eggs and 11,000 hatchlings, annually. Sipadan
Island alone can reach to more than 1,000 green turtle nests annually. The
Sipadan Island has a bigger nesting population hence suggesting that within
the Semporna district, Sipadan Island is the most important green turtle
rookery followed by the northeast islands. The northeast islands do not
represent the largest nesting aggregation of green turtles in the state of
Sabah.Tthe Turtle Islands Park off Sandakan remains the largest with over
100,000 turtles nested since 1980 (Pilcher & Basintal, 2000).
The limited data on hawksbill turtles is not enough to determine the accurate
size of the nesting population. By applying the mean clutch frequency of
Turtle Islands Park (2.7 nests) (Pilcher & Ali, 1999), the annual population in
the northeast islands can range from three to 17 turtles annually. This
indicates a very small nesting population in contrast to more than 2,200
hawksbills documented in Turtle Islands Park. However, this small population
is consistent with other rookeries such as Chagar Hutang (Chan & Liew, 1999)
and Sipadan Island (Bavoh, pers. comm). In any case, the extremely low
population renders it very vulnerable to local extinction.
No Olive Ridley nestwas found within this survey period, in contrast to the
one nest in 2010 in Pandanan Island, and a probability in Timba-Timba
Island reported by Jolis & Kassem (2011). This may be due to observation
inconsistency, where the females may have nested during this survey period
but were not observed. However, with the documentation of only a single
Olive Ridley turtle nest in 2010 and the fact that female turtles nest more than
once per season, it may suggest incorrect identification of the species by the
team in 2010. Northeast islands may be the nesting area for only green and
hawksbill turtles, which is in contrast to Jolis & Kassem (2011). Mortimer
(1991) stated the probability of such nesting in Sipadan Island, however no
confirmed nesting has been reported yet.
The nesting season and peak months for both species are similar to the Turtle
Islands Parks (Pilcher & Ali, 1999), Sipadan Island (Basintal, 2002) and
previous study (Jolis & Kassem, 2011), but is in contrast to discreet open-
closed nesting seasons at other rookeries in West Malaysia (Chan & Liew,
1999; Pilcher, 2006; Department of Fisheries Malaysia, 2008).
50
The nesting procedure from emergence to return is similar to that described
by Hendrickson (1982). The nesting timing for both species is similar to most
rookeries (Chan & Liew, 1999; Pilcher, 2006). It is acknowledged that the
frequency of daytime beach surveys was not as intensive as those during the
night, but the infrequent occasion in which they were encountered, coupled
with previous findings for both species (Witzell, 1983; Hirth, 1997) suggests
that daytime nesting is not favoured by green and hawksbills in northeast
Semporna. The nesting was not linked to tidal fluctuations indicating the reefs
surrounding the islands did not prevent nesting even at low tide. This is
consistent to the Saudi Arabian Gulf population (Pilcher, 2000).
The internesting interval of green turtles is consistent with other rookeries
(Pilcher, 2000). The length of nesting season calculated individually for green
turtles is seen to be slightly shorter than those at Turtle Islands Park. The
remigratory interval is higher than those on Turtle Islands Park.
The average minimum curved carapace length and width of green turtles are
in close agreement with the turtles in Turtle Islands Park. However, the sizes
for hawksbill turtles are slightly larger than those in the Park (Pilcher & Ali,
1999). The wide variation in size of mature breeding females in the northeast
islands is common among marine turtles. The relatively wide spread of
lengths within the nesting population suggest some span of age classes, and a
degree of recruitment into the mature, breeding age classes. This implies that
the nesting population is healthy and dynamic, similar to those in Qatar
(Pilcher, 2006).
The average green clutch size is comparable to Turtle Islands Park. Hawksbill
clutches have a higher mean than other rookeries at Turtle Islands Park and
the Middle East (Witzell, 1983; Pilcher, 2006) but smaller than at Chagar
Hutang (Chan & Liew, 1999). An increase of number of eggs and hatchlings
were seen between Jolis & Kassem (2011) and present study. Eggs have
increased 56% for green and 10% for hawksbill. Hatchlings have increased
60% for green and 16% for hawksbill. These increases are likely due to
increased patrol effort where more nests were found and transported followed
by more females nesting in the area.
The incubation period of green hatchery incubated nests on Pom-Pom and
Mataking islands is high on the global scale, generally higher than other
studied populations (Hirth, 1997). This also applies to hawksbill nests as
higher than other populations (Pilcher & Ali, 1999).
An increase in average hatchery hatching success rates at Mataking and Pom-
Pom islands in comparison to Jolis & Kassem (2011) suggests improved
hatchery operations with proper handling of eggs and suitable depth in which
the eggs were reburied in the hatchery. The hawksbill emergence and hatching
successes were found higher compared to Turtle Islands Park (Pilcher & Ali,
1999), while the incubation successes for green nests were consistent with
other populations (Pilcher & Basintal, 2000).
There was a low incident of site fixity between successive nesting attempts on
an individual basis. However, the observation of only one renesting greens on
51
Pandanan was found on Mataking Besar, suggesting a strong degree of site
fixity of at least ‘island’ magnitude which is similar to other sites (Pilcher &
Ali, 1999; Pilcher, 2000; Pilcher & Basintal, 2000). It is probable that once the
nesting island has been determined from the first nesting season after
maturity, the actual nesting location on the island is not important. This
indicates the need for some form of protection to all available beaches to
provide opportunities for nesting.
The short-term recapture rate of nesting females is not reasonable enough to
make a conclusion on its population condition. However, with the consistent
low current recapture rates documented so far, it suggested that overfishing
and exploitation of these tagged individuals from the population or a high
degree of tag loss where remigrant individuals were re-tagged as recruits.
Observation of scars from previous tagging was not recorded by teams, thus
preventing further confirmation of such view. The high rate of tag loss in
Turtle Islands Park is believed to be the main cause of low recaptures (Pilcher
& Basintal, 2000). This may apply to the Northeast islands as well, apart from
increasing poaching cases for adult turtles in Sabah waters (Anon, 2014a;
Anon, 2014b).
Including data from Jolis & Kassem (2011) (2006 to 2010), nesting numbers
have increased 62% from 172 to 753 for greens, and 10% from 72 to 88 for
hawksbills. Fluctuations in nesting numbers have been documented at a
number of rookeries (Bjorndal, 1980; Pilcher & Ali, 1999) but it is observed
that this may not be the case for the northeast islands. The short-term nesting
trend in northeast islands appears that nesting volume is in an upward trend.
However, the interpretation of these data is inconclusive and in addition to
inconsistencies in data collection with little quality control (across the three
years), this may well be skewing the readings and be more of a representation
of an increase in effort than an actual nesting population trend. This similar
trend was also seen in other rookeries (Pilcher, 2006) (Figure 49, Table 31).
The drop in the recorded nest numbers for 2013 may likely be due to the
reduced patrol effort of the resort’s monitoring teams. Patrols were not
allowed to be conducted as instructed by enforcement personnel (Police and
Army) from March to July, and November to December, and later resumed
with intermittent effort on 2014 for safety measures as a result from the
kidnapping case at Pom-Pom Island (Anon, 2013a) and standoff at Lahad
Datu (Anon, 2013b). It was informed that in light of the resumed patrols, the
monitoring teams were still very concerned with their safety at night. Seeing
that safety issues have become an increasing concern where this may prolong
and be made a priority in the coming years, the reduction of effort will lead to
a further drop in nesting numbers documentation and decrease in tagging
saturation (where not all nesting females were encountered and tagged). It
was estimated that not 100% of the turtles nesting at least on Pom-Pom and
Mataking Islands were encountered during the surveys. In the coming years,
determination of nesting population trends, size, and nest numbers will be
calculated as an underestimation and such discussion may need to be carefully
concluded.
52
Table 31: Nesting volume in the northeast islands, 2006 – 2013.
Species
Jolis & Kassem (2011)
Present study
2006
2007
2008
2009
2010
2011
2012
2013
Green
6
19
15
52
80
203
357
193
Hawksbill
5
6
11
13
37
33
46
9
Figure 39: Short-term trend in nesting volume in the northeast islands, 2011-
2013.
Nest disturbances were considered rampant whereby more than 100 nests
were poached or depredated during the study period. It is important that
every egg needs to be protected to produce hatchlings, as 1 out of 1,000
hatchlings will only be able to survive until adulthood to breed. Cases
documented were higher in the community islands. Disturbances were more
likely to be poaching by humans, as estimated number of monitor lizards was
much smaller than the community population inhabiting the islands and
presence of human footprints found surrounding the events. Even though law
regulations on marine turtles exist, turtle eggs are still being consumed locally
in Semporna for unknown reasons and rate of such consumption. Current
enforcement capacity is still unable to eradicate such activity (Aris, pers.
comm.). In Peninsular Malaysia, most consumers consume turtle eggs as a
delicacy and for pleasure and less so as a source of protein or for traditional,
medicinal and aphrodisiac reasons, while a first timer eats out of curiosity
(WWF-Malaysia, 2009). This reason may be similar to Semporna. The eggs
may be consumed by the Boheyan and Kulapuan community as their level of
awareness on turtles is low; which is consistent with WWF-Malaysia (2012)
and Jolis (2014) highlighting low awareness level on laws pertaining to turtles
and questionable responses by communities on low or no consumption rate.
The non-existing documentation of nest poaching and predation on 2013 may
be due to reduced efforts in patrol where nests were poached but not
53
observed, and this suggests the total cases recorded may be an underestimate
too.
Northeast Semporna islands have extensive seagrass beds. Most of northeast
islands’ seagrass were found in water less than 3m deep and meadows were
monospecific or consisted of multispecies communities, with up to three
species present at a single location. The sandy beaches and seagrass in the
intertidal and shallow subtidal waters surrounding the northeast islands were
never mapped and this present study is the first attempt to do so. The result
obtained will be used as a baseline for future monitoring in light of the
potential boost in tourism development in the coming years. Even though
seagrass species were not determined through this mapping exercise; personal
observation indicated that the species reported by Ho et al. (2011) are present.
The distribution of the seagrass appears to be primarily influenced by the
degree of wave action (exposure), water clarity and nutrient availability, which
is also observed by Pohnpei and Ahnd Atoll (McKenzie & Rasheed, 2006). The
observation of green turtles at the seagrass beds ranging from one to 32 per
island suggested the northeast islands are suitable habitats for green turtles to
search for food. An aerial survey using drone aircraft found about 50-100
green turtles on high tide at Pom-Pom and Pandanan Islands (Tropical
Research and Conservation Centre, 2012). The result of present study
complement the TRACC result suggesting the northeast island has a large
foraging green turtle population, probably second after the Sipadan Island.
The discovery of the dead green turtle tagged at Sipadan Island suggests the
turtle was moving northwards to search for food or was on its way migrating
to its nesting originate site.
A comparison between Jolis & Kassem (2011) and Jolis (2014) is shown in
Table 32.
54
Table 32: Result comparison between Jolis & Kassem (2011) and Jolis (2014).
(-) data not discussed.
Jolis & Kassem (2011)
Present study
Study period
2006 to 2010
2011 to 2013
Nesting Species
Green, hawksbill and
olive ridley
Green and hawksbill
Nesting season
All year round
All year round
Peak months
May and extends to
September for both
species
August for green. April and
June for hawksbill.
Patroller effort
Inconsistent across years
Inconsistent across years
Nest numbers
Green: 172
Hawksbill: 72
Olive Ridley: 1
Green: 753
Hawksbill: 88
Egg numbers
Green: 15,765
Hawksbill: 8,677
Olive Ridley: 137
Green: 56,629
Hawksbill: 10,527
Hatchling
numbers
Green: 15,765
Hawksbill: 5,296
Olive Ridley: 131
Green: 40,123
Hawksbill: 7,269
Nesting timing
-
Majority at night
Tidal height
relation to
nesting
-
Majority during mid-tides for
both green and hawksbill
Internesting
intervals (days)
± SD
-
Green: 15.5 ± 5.30 (Range: 8-
27; n = 31)
Number of
tagged females
-
Green: 85
Hawksbill: 10
Adult female
CCLmin (cm) ±
SD
-
Green: 96.9 ± 5.99 (Range:
71.0-110.5; n = 79)
Hawksbill: 79.8 ± 4.83
(Range: 72.5-86.0; n = 9)
Adult female
CCW (cm) ± SD
-
Green: 88.2 ± 6.08 (Range:
60.0-99.0; n = 79)
Hawksbill: 72.2 ± 7.20
(Range: 60.5-82.5; n = 9)
Growth rates
cm yr-1 ± SD
-
Green:
6.0 ± 3.89 (Range: 0.5-6.0; n
= 2) (CCLmin)
3.5 ± 0.71 (Range: 3.0-4.0; n
= 2) (CCW)
Clutch size ± SD
-
Green: 87.3 ± 24.50 eggs
(Range: 24-188, n = 583)
Hawksbill: 126.4 ± 39.00
eggs (Range: 33-203, n = 85)
Clutch
-
Green:
55
frequency ± SD
1.5 ± 1.19 (Range: 1-7) at
Mataking and 1.5 ± 1.24 (1-5)
at Pom-Pom
Incubation
period (days) ±
SD
Green:
40-68 at Mataking
47-60 at Pom-Pom
46-61 at Pandanan
Hawksbill:
24-69 at Mataking
29-62 at Pom-Pom
44-74 at Pandanan
Olive Ridley:
74 at Pandanan
Green:
56.4 ± 4.14 (Range = 46-75; n
= 414) at Mataking
54.1 ± 6.26 (Range = 43-81; n
= 143) at Pom-Pom
Hawksbill:
57.9 ± 2.61 (Range = 51-66; n
= 60) at Mataking
57.4 ± 8.40 (Range = 51-85; n
= 14) at Pom-Pom
Emergence
success (%)±
SD
-
Green:
77.8 ± 23.03 (Range = 0.0-
100.0; n = 414) at Mataking
79.2 ± 18.36 (Range = 0.0-
100.0, n = 149) at Pom-Pom
Hawksbill:
69.9 ± 26.6 (Range = 0.0-
100.0; n = 60) at Mataking
77.4 ± 19.36 (Range = 35.2-
97.2, n = 13) at Pom-Pom
Hatching
success (%)±
SD
Green:
57.4 (Range: 0.0-98.7; n
= 150) at Mataking
67.2 (Range: 0.0-95.5; n
= 13) at Pom-Pom
81.9 (Range: 61.6-100.0;
n = 9) at Pandanan
Hawksbill:
49.9 (Range: 0.0-100.0;
n = 51) at Mataking
75.8 (Range: 32.6-95.0;
n = 13) at Pom-Pom
87.8 (Range: 78.4-95.4;
n = 8) at Pandanan
Olive Ridley:
95.6 at Pandanan
Green:
78.6 ± 22.91 (Range = 0.0-
100.0; n = 414) at Mataking
80.4 ± 17.88 (Range = 0.0-
100.0, n = 149) at Pom-Pom
Hawksbill:
70.9 ± 26.82 (Range = 0.0-
100.0; n = 60) at Mataking
78.6 ± 18.39 (Range = 41.0-
97.2, n = 13) at Pom-Pom
Poached nest
numbers
Identified as a threat but
not quantified
101 green and 3 hawksbill
nests
56
7. Conclusion and Recommendations
This present study concluded that the Semporna northeast islands:
Are an important nesting and foraging of green and hawksbill turtles
population in the Semporna district;
Contain suitable beaches for nesting and seagrass beds for feeding
grounds,
Are of high conservation importance locally and regionally, and
Are threatened by various sources of mortality ranging from their
habitats to the turtles.
The following lists key recommendations in the northeast islands to conserve
and manage the turtle populations:
Research and monitoring
o Develop long-term project which continues the existing
work and other existing data. Trend is so far short term and
require more than 20 years make conclusion on population
status either going upwards or vice versa. Trends in nesting
numbers, identification of re-migrant turtles, incubation success
and hatchling survival should be determined over successive
seasons;
o Introduce a standardised and consistent monitoring of
nests and turtles on the beaches by trained teams with
consideration for their safety during patrolling as well as to
initiate site-based monitoring teams at remaining nesting
beaches which are Pandanan, Timba-Timba, Kulapuan and
Boheyan to start accurately collecting data and prevent further
nests disturbances;
o Determine genetic stock of northeast islands nesting
turtles originate by introducing high-cost satellite telemetries
that maps the migration behaviour of the turtles or collect blood
samples for mtDNA and nuclear DNA markers analysis which
should be carried out in well-established laboratories. Such
findings from this DNA analysis will introduce better
collaboration with other countries in identify the movement and
determine suitable measures in protecting the nesting females.
o Practice sharing of data on nesting numbers and tagging
to relevant existing regional and global projects or initiatives
such as the Sulu-Sulawesi Marine Ecoregion, Coral Triangle
Initiative.
Protection
o International cooperation is necessary to address local and
regional issues relating to the nesting population of
turtles in this area which may be threatened by overexploitation
or overfishing of the tagging population. This may include
57
engagement with local enforcement agencies in determining
location of turtles being targeted, slaughtered and trade routes
but not limited to adults but should also include eggs;
o Implement a collaborative conservation of the turtle
population in the area through cooperation of multi agencies
and organisations that look into long-term management of both
nesting beaches and habitats of the area. The Semporna turtle
management body created in 2012 and led by Sabah Wildlife
Department is the suitable platform for collaboration on turtle
protection;
o Advocate implementation of turtle-friendly development
practices for the northeast islands, which recognise the
importance of turtles and habitats through regulated
development along the nesting beaches and foraging grounds, to
continue providing opportunities for turtles to nests and forage.
Practices should include but are not limited to guidelines of
controlled fast-moving craft such as dive boat movements along
the reefs and seagrass beds to prevent turtle mortality from boat
strikes, and adoption of shielding or reduction lighting, colour
and intensity.
o Incorporate study findings of these important habitats in any
existing or upcoming management of the district. The marine
spatial planning is a suitable tool in ensuring habitats of these
turtles are still being considered or accounted in any town
planning’s together with tourism and fisheries development in
collaboration with various stakeholders.
Awareness
o Educate Boheyan and Kulapuan community in the value
of conservation of turtles and the lack of mystic powers
in their eggs. A directed awareness programme should be
developed to highlight the turtles’ protected status and
deprivation that egg collection causes. In addition, the
programme should also provide them with the knowledge tools
to assist in conservation and management efforts such as
employing egg poachers to be patrollers to seek nests and
incubate eggs successfully, to reduce nests poaching.
Management
o Ensure existing turtle hatcheries are designed and
operated appropriately by trained personnel with adequate
shading to produce a balanced ratio of in the sex of hatchlings,
while efforts should be made to work towards implementation of
in situ incubation and ultimately phasing out hatcheries. The
hatcheries should be guided by trained professionals who will
consider all aspects of turtle biology and behaviour during the
hatchery operations.
58
8. References
Abdullah, A. (2012). Personal communication. The Reef Dive Resort.