Download Nesting Activity and Conservation Status of the

Journal of Life Sciences 6 (2012) 74-79
Nesting Activity and Conservation Status of the Hawksbill
Turtle (Eretmochelys imbricata) in Persian Gulf
Seyyed Mohammad Bagher Nabavi1, Ruhollah Zare2 and Mahdieh Eftekhar Vaghefi1
1. Department of Marine Biology, University of Marine Sciences and Technology, Khoramshahr, Khozestan, Iran
2. Department of Marine Biology, University of Chabahar Maritime and Marine Science, Chabahar, Iran
Received: December 05, 2010 / Accepted: February 21, 2011 / Published: January 30, 2012.
Abstract: Nesting activity, declining factors and conversation strategy of hawksbill turtle (Eretmochelys imbricata) in Persian Gulf
islands investigated. Nesting analysis and hatchability has been monitored by counting. Our management strategy has been useful
significantly in preserving hawksbill turtle existence. Depletion prevented, nesting habitats protected and better conservative programs
designed.
Key words: Hawksbill turtle (Eretmochelys imbricata), Persian Gulf, nesting season, conservation.
1. Introduction
Globally, populations of sea turtles are declining and
experiencing serious threats to their survival and are
considered internationally as species of conservation
concern. Over-hunting for their shells and meat, the
collection of eggs from turtle nests, threatened by
coastal development, pollution and pathogens, global
warming and fisheries impacts, coastal development,
pollution and pathogens, global warming and fisheries
impacts are some factors attributing to the endangered
status of turtles. Among these factors, fisheries impacts
are thought to be one of the leading causes for sea turtle
death and injury worldwide and can occur when turtles
bite baited hooks, become entangled in fishing lines,
are crushed by dredges, or otherwise held underwater
by a variety of fishing methods (Figs. 1-7). Due to this
status, they were listed in the World Conservation
Union “Red List of Threatened Animals”; listed in the
Appendix 1 of the Convention on International Trade
in Endangered Species of Wild Fauna and Flora
(CITES).
Fig. 1 Small turtle found in Sheedor Island.
Fig. 2
Marine turtle in Hendooraabee for use in
restaurants.
Corresponding author: Ruhollah Zare, Ph.D., research
field: marine biology. E-mail: [email protected].
Nesting Activity and Conservation Status of the Hawksbill Turtle
(Eretmochelys imbricata) in Persian Gulf
75
Fig. 3 Hawksbill turtle captured in the net in Kish Island.
Fig. 6 Different between normal and abnormal eggs.
Fig. 4 Hawksbill turtle hatching in sand around bushes.
Fig. 7
Shore erosion, a natural factor for eliminating
nesting in Sheedor Island.
use of powered boats in turtle hunting, commercial sale,
habitat degradation, incidental by-catch in fishing gear,
and the large scale harvesting of eggs in rookeries [2].
Fig. 5 Green turtle killed by a boat in Hormooz Island.
The factors that are known to cause decline in sea turtle
Nesting density of hawksbill turtles is low
populations are generally similar but differences do
throughout its range [1]. This means that all turtle
exist in terms of importance for different populations
species are considered endangered by international
i.e., in different parts of the world, and with changing
trade to such an extent that if commercial trade is not
laws and technologies through time [3]. For example,
eliminated with respect to these species, they will
before the widespread use of trawlers and high seas
become extinct.
gill-nets, turtle mortality caused by fishing was
It is believed that the declining turtle populations in
minimal but laws were not in force to protect turtles
the Persian Gulf has been accelerated by the
and their products. Hence, there was widespread
breakdown of traditional conservation practises, the
hunting of turtles for meat, shell and leather. Eggs were
76
Nesting Activity and Conservation Status of the Hawksbill Turtle
(Eretmochelys imbricata) in Persian Gulf
affect any species. Natural predation on eggs and
the nearest building, street, or other landmarks. These
locations were later cross-referenced to the nearest
survey marker. Nest and false crawl locations were
recorded using Global Positioning System (GPS)
receivers. The field survey also attempted to assess the
suitability of the beaches for turtle nesting. The
assessment only looked at the surface level of the beach
area at high water mark (through which the turtle
would crawl) and the nesting area (above high water
mark). When there were many nests requiring
relocation, additional trips were occasionally necessary.
After recording all pertinent information, the crawl
marks were obliterated to avoid duplication.
Daily beach surveys commenced at sunrise or 6:00
a.m.. Surveys continued through May 25th.
hatchlings is thought to be kept in check by natural
2.1 Time
also collected extensively for food. Seas were not as
polluted then, hence mortality caused by plastics, tar
balls, pollutant induced diseases were not as extensive.
Similarly, the degree of importance of factors
threatening turtles in different parts of the world does
differ. A constant cause for decline, independent of
time, is when mortality is greater than recruitment.
Mortality and recruitment vary, depending on
predation, food availability and quality, habitat quality,
and many other factors. Because the life cycle of a sea
turtle is complex, and includes large periods of time
and large expanses of the planet, mortality can occur at
many places and many times during an individual
turtle’s life. Natural threats are indiscriminate and may
balances of predator prey relationships. Predation is so
high that it is obvious that a number of terrestrial,
marine and avian species depend on sea turtles as a
source of protein (Loghmani, M). Anthropogenic
threats (Table 1) to nesting habitats are again
indiscriminate and driven more by coastal development,
industrialization and the recreational opportunities
provided by coastal environments.
In addition to fulfilling statutory requirements, the
purposes of the project were:
(1) to relocate eggs from nests deposited in sites
threatened by natural processes or human activities and
thus maximize hatchling recruitment;
(2) to survey sea turtle nesting patterns accurately to
document historical trends and assess natural and
anthropogenic factors affecting nesting patterns and
densities;
(3) to assess the success of sea turtle recruitment and
of hatchery operations in terms of nesting success,
hatching success and total hatchlings released;
(4) to inform and educate the public about sea turtles
and their conservation.
2. Materials and Methods
Each nest location was initially recorded relative to
The research was conducted from March through
May 2007. This is the nesting season for hawksbill sea
turtles in the region.
2.2 Study Area
 Qeshm is the biggest island in the Persian Gulf near
the straits of Hormoz.
 Shidvar Island has an area of 8 sqkm, a coastline of
5.5 km.
 Hendourabi Island has a coastline of 20 km.
 Lavan Island is an Iranian Island in the Persian Gulf.
It has an area of 76 km².
 Hormuz Island is an Iranian Island in the Persian
Gulf. It is located in the Straits of Hormuz and is part
of the Hormozgān Province. It has an area of 42 km2
(Fig. 1).
3. Results
3.1 Numbers of Nests
The numbers represent the actual tally of records
recorded during the surveys, some of which may not
represent a good estimate for the month due to limited
surveys conducted on some beaches during some
months (Table 1).
77
Nesting Activity and Conservation Status of the Hawksbill Turtle
(Eretmochelys imbricata) in Persian Gulf
the only stretch used in the entire island by Hawksbill
turtles for nesting and laying eggs. The coastline,
therefore, represents an important and strategic
Hawksbill hotspot.
 2 km of the northern and eastern shores of Shidvar
Island are suitable for the nesting of turtles.
 2 km of Hendourabi Island is suitable for marine
turtle nesting. Most parts are rocky shores, but there are
some small a large sandy beaches suitable for nesting
in east, north east and south
 Lavan Island has one of the four major terminals for
export of crude oil in Iran and some of suitable nesting
areas are under destruction.
Fig. 8 Persian Gulf and the studied islands.
3.2 Threatening Factors
During our investigation in different area of the
studies region, variety of factors which considers as
threat to sea turtle population was found. Table 2 has
listed those factors.
4. Discussion
In the past there has been a great deal of nesting of
the hawksbill turtle at Persian Gulf but eggs collection
and entanglement of adult females is rife.
 Shibderaz Village is in the centrally-located
southern coastline of Qeshm Island which is currently
Table 2
Table 1
Total hawksbill nests and nesting densities
expressed as nest per kilometre.
Island
Beach length(km)
Total nests
Shidvar
36
2.1
Lavan
24
3.2
Qeshm
56
6.7
Hormuz
34
3.4
Farour
35
4.6
Hendurabi
46
5.7
231
25.7
Overall
Current anthropogenic threat to sea turtle populations in Some Persian Gulf Islands.
Threat
Habitat alteration and loss
Beach armouring (e.g., concrete sea walls)
Beach nourishment/sand mining
Beach cleaning and beach driving
Human presence on beach
Artificial light
Boat strikes
Animal predation at rookeries
Oil pollution
Other pollution sources and entanglement
Fishing and incidental capture
Shrimp trawling
Pelagic fishing gear
Gill nets
Traditional and commercial fishing
Egg harvests
Adult harvests
Shidvar
Yes
No
No
No
Yes
No
Yes
Yes
?
Yes
No
No
Yes
No
Yes
Yes
Yes
Lavan
Yes
Yes
Yes
No
Yes
No
Yes
No
Yes
Yes
Yes
No
Yes
No
Yes
Yes
Yes
Qeshm
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Hormuz
No
No
No
No
Yes
No
Yes
Yes
?
Yes
Yes
No
Yes
No
No
No
No
Farour
No
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
Hendurabi
No
No
No
No
Yes
No
Yes
No
No
No
No
No
No
No
No
No
Yes
78
Nesting Activity and Conservation Status of the Hawksbill Turtle
(Eretmochelys imbricata) in Persian Gulf
Main threatening factors of sea turtles in Persian
Gulf are considered as:
(1) In most parts of the nesting sites egg collection
for traditional usage as well as aphrodisiac purposes is
usual;
(2) In some parts turtles harvest for their meat for the
same purposes too;
(3) Different kinds of pollutions are usual, like the
debris, oil and light;
(4) By catch in fishery activities is another important
threat, as the turtle habitats are important fishing
grounds too;
(5) Natural predators like the other parts of the world
are usual, like the mammals, birds, crabs and insects;
(6) Density of the body pits in the small beaches
prevent hatchlings to reach the sea;
(7) Mismanagement causes problems in some parts;
(8) Boat strike is usual and increasing in some parts;
(9) Different kinds of coastal area development is
another threat for the nesting sites and turtles;
(10) Other natural factors like the erosion is usual in
most places, specially in small beaches.
5. Conclusion
Conservation measures and conservative programs
that prevent sea turtles from being killed would be of
priority. These two plans are as follow.
5.1 Conservation Measures
These measures are needed to be planned to be
practical and the objective are categorized as below:
 to reduce the incidental catch of adult and juvenile
turtles in fishing gears, e.g.: (i) use of TEDs in trawlers
(shrimp and fishing); (ii) regulate or ban the use of high
seas gill-nets; (iii) regulations to protect turtles or
restrict the use of fishing methods harmful to turtles off
their nesting grounds during the nesting season.
 to curb the hunting and trade of live turtles, adults
and juveniles, for meat and other turtle products.
 to reduce commercial exploitation of eggs, both
legal and illegal.
 to prevent the destruction of nesting grounds by
beachfront development, seawalls, land reclamation,
etc..
 to control the destruction of feeding grounds by
trawlers, pollution, land reclamation, etc..
 to avoid the killing or drowning of turtles in
man-made structures (e.g., oil rigs) or by powered
watercrafts.
 to restrain marine pollution to reduce the mortality
of hatchlings, juveniles and adults caused by marine
debris like plastic bags, tar balls, styrofoam, etc..
 to prevent the inducement and spread of diseases
that may be anthropogenically related, e.g.
fibriopapillomas.
5.2 Conservative Programs
The conservation programs are described as below:
 nomination of sea turtles as “endangered animals”
of the country;
 there was a fine of about 3,200,000 Rials for each
killed turtle which doubled in the past year (6,400,000
Rials), about US$700;
 and also fine for egg collection, about $US 233 for
each;
 nominating of the nesting sites as “under
management and control area” like Mond protected
area and shidvar wildlife refuge;
 monitoring of the sites by DOE guards.
In order to respond to a critical conservation
situation, as is the case of these sea turtle populations,
an agreement must fulfill some requirements:
(1) it must include all, or most of the countries
involved in the problem.
(2) it must be an “agile” organization, capable of
facing a dynamic situation without getting bogged
down with time consuming formalities.
(3) it must turn words into actions very rapidly; and
perhaps also.
(4) it must have the capability to implement and
execute a comprehensive program.
Nesting Activity and Conservation Status of the Hawksbill Turtle
(Eretmochelys imbricata) in Persian Gulf
(5) if possible, it is preferable that the agreement is a
binding one. It is quite clear that the institution must
have a level of credibility with the different
stakeholders.
Acknowledgment
The authors express their appreciation to
Department of Environment of Hormozgan province
for their serious and great cooperation in this research.
Our thankful reward is to local fishermen of Hormoz,
Shidvar, and Hendourabi Islands for their kind and
unconditionally support.
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