MALAYSIA CORAL REEF CONSERVATION PROJECT: PULAU

Transcription

MALAYSIA CORAL REEF CONSERVATION PROJECT:
PULAU REDANG
R EPORT TO THE D EPARTMENT OF MARINE PARKS, MALAYSIA.
M ARCH – SEPTEMBER 2004
December 2004
- Prepared by James Comley, Director of Marine Science
Ryan Walker, Marine Science Coordinator
Joanne Wilson, Project Scientist
Alice Ramsay, Research Assistant
Inge Smith, Research Assistant
Peter Raines, Managing Director
Coral Cay Conservation Ltd
13th Floor, The Tower,
125 High Street, Colliers Wood
Department of
Marine Parks,
Malaysia
London, SW19 2JG, UK
Tel: +44 (0)870-750-0668
Fax: +44 (0)870-750-0667
Email: info@coralcay.org
www.coralcay.org
Contents
MCRCP – Pulau Redang Report
CONTENTS
ACKNOWLEDGEMENTS .............................................................................................. I
EXECUTIVE SUMMARY..............................................................................................II
LIST OF FIGURES ........................................................................................................ III
LIST OF TABLES ............................................................................................................V
1.
INTRODUCTION ......................................................................................................6
1.1
1.2
1.3
2.
Project Background .......................................................................................... 6
Pulau Redang Marine Park ............................................................................. 7
Project Aims ...................................................................................................... 8
METHODS...............................................................................................................12
2.1
Volunteer training ........................................................................................... 12
2.2
Survey strategy................................................................................................ 15
2.2.1
The Concept of ‘Survey Sites’ ................................................................... 15
2.3
Baseline transect technique ............................................................................ 17
2.4
Data analysis .................................................................................................... 20
2.4.1
Baseline data............................................................................................. 20
2.5
Management Rating ........................................................................................ 21
3.
RESULTS ................................................................................................................24
3.1
Coral Reef Survey Progress ........................................................................... 24
3.2
Oceanographic data ........................................................................................ 26
3.2.1
Wind speed and Direction......................................................................... 26
3.2.2
Salinity ..................................................................................................... 26
3.2.3
Water Temperature ................................................................................... 27
3.2.4
Current Strength and Direction ................................................................ 28
3.2.5
Underwater Visibility................................................................................ 29
3.3
Anthropogenic data ........................................................................................ 31
3.3.1
Boat Activity.............................................................................................. 31
3.3.2
Surface and Subsurface Impacts............................................................... 32
3.4
Multivariate Analysis and Habitat Definitions ............................................ 35
3.4.1
Habitat Descriptions ................................................................................. 35
3.4.2
Univariate Measures of Habitat Biodiversity........................................... 40
3.5
Fish Populations .............................................................................................. 41
3.5.1
Fish Assemblage variation between Survey Sector .................................. 42
3.5.2
Fish Assemblage variation between habitat types .................................... 43
3.6
Invertebrate Populations ................................................................................ 46
3.6.1
Invertebrate Populations by Survey Sector............................................... 47
3.7
Management Value ......................................................................................... 50
4
DISCUSSION ..........................................................................................................55
4.1
4.2
4.3
Training ............................................................................................................ 55
Oceanography and Anthropogenic Impact .................................................. 55
Benthic Data .................................................................................................... 57
Prepared by Coral Cay Conservation
Contents
4.4
4.5
4.7
Fish Data .......................................................................................................... 57
Invertebrate Data ............................................................................................ 57
Management findings ..................................................................................... 59
REFERENCES .................................................................................................................61
APPENDIX I ....................................................................................................................63
Acknowledgements
ACKNOWLEDGEMENTS
This study would not have been possible without the support of numerous organisations
and individuals, only some of whom can be listed here. We gratefully acknowledge all
the support given to the fieldwork and report preparation.
The success of the Malaysia Reefs and Islands Conservation Project – 2003 would not
have been possible without the vision and leadership provided by the Department of
Marine Parks, Ministry of Natural Resources and Environment, Government of Malaysia.
Particular thanks must go to Mr Gulamsarwar, Ms Raja Yana Meleesa, Ab. Rahim Gor
Yaman (Head of Unit, Marine Parks of Terengganu); Abd. Khalil Abd. Karim, as well as
all of the other staff at both federal and state level and the manpower on the ground in the
Redang Islands because without their tireless assistance, this program would not have
possible.
In addition, gratitude to the Economic Planning Unit of the Prime Ministers Office who
provided research permission to allow the work presented in this report to be undertaken.
The foresight of one individual, Graham Wallis, Honorary Patron of Coral Cay
Conservation (CCC) and the Malaysia Coral Reef Conservation Project (MCRCP’s)
sponsor in Malaysia has helped the program move along and gather momentum every
step of the way.
Thanks go to Malaysia Airlines Systems Sdn. Bhd. and Malaysia Airlines Kargo Sdn.
Bhd. whose logistic help in transport equipment and personnel to the expedition site has
ensured the project could proceed unhindered.
Thanks also go to all of the staff at the British High Commission in Kuala Lumpur with
special thanks to Mark Canning for his support and interest.
We are grateful to all of the academic institutes, Government bodies and NonGovernmental Organisations in Malaysia that have provided support and advice during
the course of this program and report presentation; Prof Phang Siew Moi, Dr Azhar
Hussin and Dr Affendi Yang Amri from University Malaya; Prof Dick Sinn-Chye Ho
from the National Oceanographic Directorate at the Ministry of Science, Technology and
Environment; staff at University Kabangsaan Malaysia; ReefBase and at the World Fish
Center, Penang; Leela Panikkar from Treat Every Environmental Special (TREES) and
Jamhariah Jaafar from the Coral Reef Alliance, Malaysia (CORAL).
Finally, a huge thank you to all of the volunteer expedition members who have worked so
hard to make this program possible.
I
Executive Summary
EXECUTIVE SUMMARY
•
Development in Malaysia is concentrated in the coastal zone which places direct threats
to the coral reef and shallow tropical marine ecosystems that the country relies on for
much of its revenue generation.
•
These threats have been acknowledged by the Malaysia Government who established a
number of Marine Parks under the Department of Fisheries to facilitate the sustainable
use of the resources. In 2004 Coral Cay Conservation were invited to conduct a series of
surveys on such a Marine Park; Pulau Redang in the east coast state of Terengganu on
Peninsular Malaysia.
•
Two hundred and seventy eight baseline survey dives along seventy eight transects were
conducted to collect a data set on the coral reef resources of the Redang Archipelago in
2004.
•
The data collected has been used to identify fourteen discrete habitat types that are key to
the ecological functioning of the coral reef systems.
•
Data on fish and invertebrate populations overlaid on biodiversity and reef health
indicators has identified areas of reef that are of key management and conservation
importance.
•
Signs of impacts are presented in the data; fishing activities are still present within the
Marine Park and areas in which development has occurred show signs of human impact
such as solid waste pollution
•
Threats identified include an increase in suspended sediment concentrations, increased
solid waste pollution and possible signs of nutrient elevation around the developments, as
well as direct damage to the marine resources in areas used intensively for recreational
activities.
•
Key areas where specific management objectives need to be met are geographically
identified. They include the less developed areas of the North West of Redang as well as
areas around the Marine Park Center Island, Pulau Pinang. It is interesting to note that
this latter area is subjected to heavy pressure from recreational users, yet the tight
management controls employed by the Marine Park initiatives appear to limit the impact
caused by this intensive use.
•
Through a collaborative venture between CCC, Department of Marine Parks and the
Malaysian Centre of Remote Sensing, it is planned to develop the field data set into a
fully integrated Geographic Information System using high-resolution remotely sensed
data.
•
This GIS will allow improved management planning through the identification of key
management areas in which development needs to be tightly controlled as well as more
general use zones in which development can be controlled through proper mitigation
initiatives.
II
List of Figures
LIST OF FIGURES
Figure 1.1.
The Redang Islands in relation to Peninsular Malaysia, Kuala Lumpur and
Singapore. ......................................................................................................................9
Figure 1.2.
The Redang Islands in relation to major settlement centres on mainland
Peninsular Malaysia. .....................................................................................................10
Figure 1.3.
The Redang Archipelago. .............................................................................11
Figure 2.1.
Location of the survey sectors around Redang Island. .....................................16
Figure 2.2.
Schematic diagram of a baseline survey dive team..........................................18
Schematic diagram (aerial aspect) of an example of a reef area mapped by divers
Figure 2.3.
during a sub-transect survey. .........................................................................................18
Figure 2.4.
The use of a secchi disc to assesses vertical water clarity. ................................19
Figure 3.1.
Location of start points (red symbols) of Baseline Transects conducted by CCC
around Redang Island between March and September 2004.............................................25
Figure 3.2.
Radar diagram showing the prevailing winds recorded during MCRCP.. ..........26
Figure 3.3.
Mean salinity recordings for all surveys in the project area in 5m depth classes
throughout the water column. . .....................................................................................27
Figure 3.4.
Mean water temperatures for all surveys in the project area in 5 metre depth
classes throughout the water column. .............................................................................28
Figure 3.5.
Mean underwater current strength and direction recorded in the Redang
Archipelago during surveys...........................................................................................29
Figure 3.6.
Mean Secchi Disc recordings of vertical visibility in metres (± S.D.) for each
survey sector................................................................................................................30
Figure 3.7.
Mean horizontal visibility recordings by divers in metres (± S.D.) for each survey
sector.
....................................................................................................................30
Figure 3.8.
Mean frequency of boat sightings within 1 km of survey sites for each survey
sector.
....................................................................................................................31
Figure 3.9.
Percentage boat activity recorded within each survey sector. ...........................32
Figure 3.10. Percent frequency of the occurrence of surface impacts within each survey sector.
....................................................................................................................33
Figure 3.11. Percent frequency of occurrence of sub-surface impacts within each survey sector
....................................................................................................................33
Figure 3.12 Diver impressions of the aesthetic and biological value of sites surveyed within
each sector. ..................................................................................................................34
Figure 3.13. Dendrogram derived from cluster analysis of CCC baseline survey data collected
during the Redang Island Project. ..................................................................................36
Figure 3.14. More frequently encountered fish families in each survey sector......................42
Figure 3.15. Less frequently encountered fis h families in each survey sector.. .....................42
Figure 3.16.
Mean abundance of more frequently observed fish families found associated
with each habitat...........................................................................................................43
Figure 3.17. Mean abundance of less frequently observed fish families found associated with
each habitat.. ................................................................................................................44
Figure 3.18. Commonly encountered Invertebrate Taxa in each Survey Sector.....................48
Figure 3.19. Less frequently encountered Invertebrate Taxa in each Survey Sector.. ............48
Figure 3.20
Mean abundance of commonly observed invertebrate families by habitat type..49
Figure 3.21 Mean abundance of less frequently observed invertebrate families by habitat
type.
....................................................................................................................49
Figure 3.22. Calculated Management values for each survey transect completed during the
Redang Island Phase of the MCRCP ..............................................................................52
III
List of Figures
Figure 3.23
Conservation Management Rating image. ......................................................54
IV
List of Tables
LIST OF TABLES
Table 1.
Main aims, objectives and anticipated outputs of the Redang Island phase of the
Malaysia Coral Reef Conservation Project........................................................................8
Table 2.1.
CCC Skills Development Programme timetable for CCC volunteers during the
MCRCP. ....................................................................................................................13
Table 2.1. (Continued). CCC Skills Development Programme timetable for CCC volunteers
during the MCRCP. ...................................................................................................14
Table 2.2. Ordinal scale assigned to life forms and target species during baseline surveys. ...19
Table 3.1. Quantitative description of the fourteen habitats defined from the data collected in
the Redang Islands........................................................................................................37
Table 3.1 (Continued). Quantitative description of the fourteen habitats defined from the data
collected in the Redang Islands. .....................................................................................38
Table 3.1 (Continued). Quantitative description of the fourteen habitats defined from the data
collected in the Redang Islands. ................................................................................39
Table 3.2.
Univariate biodiversity measures of the fourteen Habitats derived from Cluster
Analysis from data collected during the Redang Island phase of the MCRCP....................40
Table 3.3.
Calculated mean abundance ratings assigned to each major fish family (or
subfamily for Serranids) during CCC Baseline surveys of the MCRCP............................41
Table 3.4. Pair wise multivariate comparison between fish assemblages associated with each
habitat. ........................................................................................................................45
Table 3.5. Univariate biodiversity measures calculated for fish assemblages found associated
with each habitat...........................................................................................................46
Table 3.6. Calculated mean abundance ratings assigned to each major invertebrate taxa during
CCC Baseline survey dives during the MCRCP. .............................................................47
Table 3.7.
Calculated values for five reef health indicators; three for benthic and sessile
organisms and two for fish assemblages, found associated with each habitat defined.........51
V
Introduction
1.
INTRODUCTION
1.1
Project Background
Malaysia is one of the most affluent countries in the South-East Asia region. Its growth
has been assisted to an extent by its abundant and rich coral reef and shallow tropical
marine resources. Malaysia enjoys benefits from the world’s most rapidly growing
industry; tourism. Tourism currently generates 11% of the Global Gross Domestic Project
and is forecast to continue to grow with a predicted 1400 million international travellers
globally by 2020 (Christ et al., 2003).
Much of the development that is occurring in Malaysia is concentrated into the narrow
coastal zone, making this a key area in the issues affecting the sustainability of this
development. The coastal zone environments, including coral reefs, are exposed to a suite
of anthropogenic impacts and threats. These include, though are not limited to,
overfishing, sedimentation, eutrophication and pollution which all result in habitat
degradation or loss. This coastal zone is, however, not limited to the maritime areas of the
mainland, but instead extends to cover the multitude of islands and islets that are dotted
around both East and West Malaysia.
The Fisheries Act of 1985 in Malaysia enabled the establishment of Marine Parks and
Reserves to help limit some of these aforementioned impacts on the fragile and unique
coastal zone environments of Malaysia, and to promote the objectives of conservation,
education and recreation.
Although excellent summaries are available for the status of the reefs throughout
Malaysia (see Ridzwan, 1994), quantitative data for the marine parks of the east coast of
Peninsula Malaysia are limited. Previous studies that have been conducted in this area
include the DoFM and WWF-Malaysia collaborative surveys in 1994 (Aikanathan and
Wong, 1994) and the surveys undertaken by Lim and Spring (1997). In 2000, WWFMalaysia undertook a series of surveys to update WWF-Malaysia’s Biodiversity Report
for the Tioman archipelago (Hendry, 2000). Later in the same year CCC undertook a
rapid assessment of reef health, status and biodiversity at 17 sites along the east coast
between Pulau Redang and P. Tinggi (Harborne et al., 2000).
Founded in 1986, CCC is dedicated to ‘providing resources to protect livelihoods and
alleviate poverty through the protection, restoration and sustainable use of coral reefs and
tropical forests’ in collaboration with government and non-governmental organisations
within a host country. CCC does not charge the host country for the services it provides and
is primarily self-financed through a pioneering volunteer participatory scheme whereby
international volunteers are given the opportunity to join a phase of each project in return for
a financial contribution towards the project costs. Upon arrival at a project site, volunteers
undergo a training programme in marine life identification and underwater survey
techniques, under the guidance of qualified project scientists, prior to assisting in the
acquisition of data. Finances generated from the volunteer programme allow CCC to
provide a range of services, including data acquisition, assimilation and synthesis,
6.
Introduction
conservation education, technical skills training and other capacity building programmes.
CCC is associated with the Coral Cay Conservation Trust (the only British-based charity
dedicated to protecting coral reefs) and the USA-based Coral Cay Conservation
Foundation.
Effective coastal zone management, including the conservation of coral reefs, requires a
holistic and multi-sectoral approach, which is often a highly technical and costly process
and one that many developing countries cannot adequately afford. With appropriate
training, non-scientifically trained, self-financing volunteer divers have been able to
provide useful data for coastal zone management at little or no cost to the host country
(Hunter and Maragos, 1992; Mumby et al., 1995; Wells, 1995; Darwall and Dulvy, 1996;
Erdmann et al., 1997; Harding et al., 2003; Harborne et al., In press). This approach has
been pioneered and successfully applied by Coral Cay Conservation (CCC) since 1986.
Following a preparatory mission in May 2001 and project launch in March 2002, Coral
Cay Conservation (CCC) and the Marine Parks Section of the Malaysian Department of
Fisheries implemented a six-month pilot project in the Perhentian Islands in 2003. The
pilot phase of the Malaysia Reefs and Islands Conservation Project (MCRCP), between
March and August 2003, aimed to provide basic data on the marine resources of the
Perhentian Islands and their status. Subject to evaluation of the outputs from this pilot
project by Government and other stakeholders, the objective is for CCC to establish a
more long-term presence on the east coast of Peninsula Malaysia in order to provide
detailed biological assessment and monitoring data, along with training, capacity building
and environmental education work.
1.2
Pulau Redang Marine Park
The Redang archipelago comprises Pulau Redang, Pulau Pinang, Pulau Ling, Pulau Ekor
Tebu, Pulau Kerengga Besar, Pulau Kerengga Kechil, Pulau Paku Besar, Pulau Paku
Kechil and Pulau Lima. In 1993, the Department of Fisheries Malaysia of the Ministry of
Agriculture (now the Department of Marine Parks, Ministry of Natural Resources and
Environment) was given the responsibility to undertake the protection of offshore islands
and surrounding marine waters. In the same year, Palau Redang was gazetted as a
fisheries Prohibited Area under Fisheries (Prohibited Areas) Regulations 1983 (Fisheries
Act, 1963). The waters surrounding the island of the Redang Archipelago have been
gazetted as a Marine Parks under the Establishment of Marine park Malaysia Order 1994
(Fisheries Act in 1995). The boundary of the marine park was established by a line
linking all points two nautical miles from the shores (low water mark) of Pulau Redang,
Pulau Lima, Pulau Ekor Tebu, and Pulau Pinang.
The goal of Pulau Redang Marine Park is to protect, conserve and manage in perpetuity
marine environment of significance and to encourage public understanding, appreciation
and enjoyment of Malaysia’s natural marine heritage. The concept is to encourage
compatible uses of the marine park within its ecological and social carrying capacity.
7.
Introduction
Very little data exists on the sate of Redangs reefs but recent Reef Check surveys suggest
that to the north of the main island, hard coral cover is in the region of 56.9%. Cover of
54.8% was recorded for what appeared to be the healthiest reefs of Pulau Paku Kecil
The shallow reefs of Pulau Lima recorded hard coral cover of 48.7%.
1.3
Project Aims
Of the studies mentioned earlier, the most recent one conducted by Coral Cay
Conservation in 2000 did not survey the coral reefs around the Redang Islands.
Consequently very little recent information exists on the status, health and biodiversity of
the coral reefs in the island group
The aims and objectives of MCRCP are to provide a baseline information set on the
condition and status of the coral reefs around the Redang Islands in 2004 (see Table 1
below). The information collected can then be used to facilitate local planning activities
by being a source of data on the spatial distribution and ecological value of discrete areas
within the Marine Park. The data presented needs to be in a readily accessible format for
use in the support of further studies and documents such as Environmental Impact
Assessments. It should also enable future temporal comparison by forming a baseline
data set of the condition and status of reef resources in the Redang Islands in 2004. In
addition, the management recommendations made will provide a framework around
which more general management initiatives can be constructed. Finally, throughout the
course of the Pilot Phase of the Malaysia Reef and Islands Conservation Project, incountry capacity building will be a key facet of the work conducted.
Table 1.
Main aims, objectives and anticipated outputs of the Redang Island phase of the
Malaysia Coral Reef Conservation Project.
AIM
Ü
Resource
assessment.
OBJECTIVE
Œ
•
Ž
•
Ü
Training and
conservation
education.
Œ
•
Ž
Undertake an initial scientific survey of
target coral reefs.
Conduct
preliminary
human
impact
assessment studies.
Establish a baseline database.
Provide preliminary management tools and
recommendations.
Provide scientific and SCUBA training for
CCC volunteers and local counterparts.
Heighten awareness of marine resources,
their use and protection.
Begin to develop a sense of community
stewardship in managing the coastal zone.
ANTICIPATED OUTPUTS
2 Initial baseline database.
2 Description of reef habitat
types.
2 Documentation of gross
anthropogenic impacts.
2 Conservation management
rating map.
2 Preliminary management
recommendations.
2 Increased
awareness
amongst
local
communities.
8.
Introduction
Redang Archipelago
SEE FIGURE 1.2 FOR
DETAIL
Figure 1.1.
The Redang Islands in relation to Peninsular Malaysia, Kuala Lumpur and Singapore. Map taken from Reef Base online at
www.reefbase.org
9.
Introduction
SEE FIGURE 1.3 FOR
DETAIL
Figure 1.2.
The Redang Islands in relation to major settlement centres on mainland Peninsular Malaysia. Map taken from Reef Base online at
www.reefbase.org
10.
Introduction
Figure 1.3.
Redang Archipelago.
11.
Methods
2.
M ETHODS
2.1
Volunteer training
Efficient and effective training is a vital component of any volunteer programme in order
that participants quickly gain the required identification and survey skills that allow them
to collect accurate and useful data. During the MCRCP, CCC used an intensive 12-day
training programme, plus one day of validation, which is outlined in Table 2.1. The
programme was designed to provide volunteers, who may have no biological
knowledge, with the skills necessary to collect useful and reliable data. The primary aim
of the lecture programme was to give volunteers the ability to discern the specific
identification characteristics and relevant biological attributes of the target organisms
they would encounter during diving surveys. The training programme was co-ordinated
by the Project Scientist (PS) and Science Officer (SO) and involved two lectures and
two dives or snorkels each day along with de-briefings and evening audio-visual
presentations. Volunteers were also encouraged to snorkel and utilise identification
guides to ensure a thorough understanding of the information provided in the lectures.
An important component of the training schedule was a series of testing procedures to
ensure that each volunteer had reached a minimum acceptable standard. Hence the
training programme concluded with a series of tests, which ensured that the volunteers
had reached an acceptable standard of knowledge. These tests used both ‘flash-cards’
and in-water identification exercises for corals and fish. Furthermore, to assess the
quality of data collected by CCC volunteers during actual survey work, two validation
exercises were undertaken. The benthic validation exercise used a test transect survey
set up and thoroughly surveyed by the PS and SO to collate a reference data set. During
Phase 1, test transects were conducted in buddy pairs with one person recording coral
and the other soft corals, invertebrates and algae (as performed by Divers 3 and 4 during
surveys; Section 2.3). Data were then transferred to recording forms and entered into a
spreadsheet where the results from each pair were compared to the reference using the
Bray-Curtis similarity coefficient (Equation 1; Bray and Curtis, 1957).
Equation 1:


B r a y - C u r t i s S i m i l a r i t y , S jk =  1 −


p

∑ X − X

ij
i
k
i= 1

p
 
∑  X + X


ij
jk 
i=1
Where Xij is the abundance of the ith species in the jth sample and where there are p species
overall.
Since it is impossible to compare volunteer fish data to a reference, validation of fish
surveys were conducted by measuring the consistency between pairs of surveyors. It is
then assumed that if surveyors are consistent they are also accurate. Therefore, both
divers within a buddy pair independently survey the whole fish list and each surveyor
fills out their own survey form and enters it onto a spreadsheet. As with the benthic
validation, the pairs of results were compared using the Bray-Curtis similarity
coefficient. These assessments were similar to the critical assessment conducted by
CCC in Belize in 1993 to test the accuracy of volunteer divers conducting baseline
transect surveys (Mumby et al., 1995).
12.
Methods
Day +1 (Tue)
ï PM
ï AM
Transfer
New vols (i.e. trained
scuba
divers)
to
Castaway
Survey dive
(Trained
Volunteers
only - see note 2)
Orientation
„Welcome & tour of
facilities
„Expedition life &
duties
„General health &
safety
„CCC
rules
&
regulations
Practical
„Scuba kit allocation
„PADI AOW Elective
Dive: PPB (6m) with
new diver volunteers
Safety briefs
„PADI RD:
Ac mods 1+2
Practical
„PADI RD: OW exc. 1
(surface only)
„OW exc. 2 (3m)
Table 2.1.
Day +2
(Wed)
No diving
Lecture 2
„Dangerous
animals!
Safety briefs
„PADI MFA:
Ac mods 1+2
„O2 therapy
„PADI tables
& quiz (OW
mods 4+5)
„CCC dive
standards
„Radio use
„Emergency
procedures
„Boat safety
„Boat
marshalling
„Use of boat
safety kit
Day +3 (Thu)
Lecture 10
„Marine
plants
&
algae
Practical
„Marine
plants
&
algae
ID
(snorkel)
„Specimen
ID
–
reference
collections
Lecture 4
„Intro
to
hard
coral
biology
Practical
„ID - coral
life
forms
(scuba- 16m)
Review
„Coral
life
forms
Lecture 3
„Intro
to
coral
reef
ecology
Practical
„Reef
orientation
(scuba-18m)
„
PADI
AOWD
Training
Elective Dive
3 (18m)
Day +4
(Fri)
No diving
Review
„ID
–
coral, fish,
inverts &
algae
ID skills
evaluation
„Inverts &
algae
(slides &
samples)
„Inverts &
algae
(snorkel)
Practical
revision
„ ID – all
fauna and
flora
(snorkel)
Day +5
(Sat)
Day +6 (Sun)
Day +7 (Mon)
Day +8 (Tue)
Day +9 (Wed)
Day +10
(Thu)
Day +11 (Fri)
No Diving
Lecture 6i
„Hard
coral ID –
target grps
Lecture 11i
„Fish
families and
species ID
Practical
„Fish ID –
Families
(18m)
Review
„Fish ID –
Families
Lecture 11iii
„Fish ID –
target species
Practical
„Fish ID –
target species
(scuba-18m)
Review
„Fish ID –
target species
Lecture 13
„Invert. ID
Lecture 15
„Intro to CCC
Reef
Survey
Technique
Practical
„CCC
Reef
Survey methods
(dry run)
„CCC
Reef
Survey methods
practice (scuba18m)
Review
„CCC
Reef
Survey technique
Lecture 17
„CCC data
validation
Review
„ID – hard &
soft corals
Skills
refresher
„Benthic
validation
(scuba-18m)
(a) Skills
validation
„Coral trail
(Snorkel)
Lecture 11ii
„Fish ID –
target species
Practical
„Fish ID –
target species
(16m)
Review
„Fish ID –
target species
Practical
„Fish ID –
target species
(scuba-18m)
Review
„Fish ID –
target species
Review
„ID – coral,
fish, inverts &
algae
Practical
„ID – coral,
fish, inverts &
algae (scuba16m)
Self-revision
„ID – coral,
fish, inverts &
algae
Practical
„Hard
coral
ID
(scuba18m)
Lecture 6ii
„Hard
coral ID
Lecture 7
„Soft coral
and
sponge ID
Practical
„Hard/soft
coral
ID
(scuba –
16m)
Review
„Hard/soft
coral ID
Practical
„Invert.
ID
(scuba-18m)
Review
„Invert. ID
CCC Skills Development Programme timetable for CCC volunteers during the MCRCP.
13.
Lecture 16
„Intro to CCC
Reef
Survey
forms,
habitat
classifications and
use of Abundance
Scales
Practical
„Practice survey
(scuba-16m)
„Data entry onto
CCC forms
Skills
validation
„Coral trail
(scuba-16m)
Review
„ID – fish
Skills
validation
„Fish
(Snorkel)
Review
„Validation
assessment
Review quiz
„CCC health
&
safety
regulations
„CCC dive
standards
„Emergency
procedures
„Local
culture
&
customs
Lecture 5
„Coral
biology and
taxonomy
ï AM
Lecture 1
„Malaysia
Review
„Expedition
Skills
Training schedule
Lecture 8
„Intro to
fish
ecology &
behaviour
Lecture 9
„Intro to
GPS
ï PM
Table 2.1. (Continued).
Review
„Coral & fish
ID (pictionary)
Lecture 12
„Ropes
&
knots
Review
„Coral, fish
and algae ID
(pictionary)
Review
„GPS
&
knots
ID skills
evaluation
„Corals
Lecture 14
„CCC data:
analysis
&
use
Safety brief
„Night-diving
procedures
Practical
„Optional nightdive (12m)
Day +12 (Sat)
Day +13 (Sun)
Day +14
(Mon)
Skills validation
Retakes if required
(fish or coral)
practice CCC Reef Survey
dive
Data collation – practice
CCC Reef Survey dive
shore dive/boat dive
Validation
required
review
Coral and soft coral
ID
Practice CCC Reef
Survey dive from
boat
EVE
EVE
Methods
Lecture 19
„Data entry to CCC
computer database –
(groups of 4)
Followed by
Data entry
retake
if
ID skills evaluation if
required
Practice CCC Reef Survey shore/boat dive
Practice
CCC
Survey dive
Followed by
Data entry
Validation
required
PADI MFA*
„Mods 3+4
Graduation!
Congratulations
on
completing the CCC Skills
Development Programme
Lecture 20
„Marine reserves
retakes of ID skills if
required
retake
Reef
if
PADI MFA*
„Mods 5+6
Lecture 21
„mangrove ecology
retakes of ID skills if
required
CCC Skills Development Programme timetable for CCC volunteers during the MCRCP.
14.
ID skills
evaluation
„Fish
(slides)
ID skills
evaluation
„Re-takes (if
required)
Lecture 18
„Other
survey
methods
Methods
2.2
Survey strategy
The survey strategy focused on gathering detailed data from a wide range of
geographical locations. The main aim was to generate data from a broad range of
habitat types that represent most reef types of the area and hence provide a thorough
overview of all of the marine resources that are found around the island.
2.2.1
The Concept of ‘Survey Sites’
During the pilot phase of the MCRCP, CCC volunteers collected data from a series of
‘survey sites’, which correspond to a particular island’s reef or part of a reef,
depending on reefal area. Surveys at each site generate a standardised data set that
will facilitate characterisation of each area and also allow powerful comparisons at a
range of spatial scales. Sites were chosen to represent: (1) popular diving areas; (2)
the ‘best’ reefs of the project area; (3) the ‘worst’ reefs of the project area; (4) a range
of reef (and hence habitat) types. Site selection was based on a combination of
existing data, local information (e.g. dive resorts), local biologists and initial
assessments (e.g. snorkelling).
The standard CCC Baseline Survey Technique transects were surveyed to provide
general data on each habitat type present. The exact number of transects at each site
varied, depending on the topography of the reef (e.g. fewer transects at those sites
with a wide or deep reef profile), but usually numbered between 3 and 20, depending
on the scale and size of each survey site.
15.
Methods
TK
TL
DK
TN
MS
LT
PB
TA
LM
PK
PT
KB
PI
PP
Figure 2.1.
ET
Location of the survey sectors delineated for purposes of data collection, analysis and reporting in this document. Two-character code
refers to database codes assigned to identify each area.
16.
Methods
2.3
Baseline transect technique
The surveys of Redang Island during the Malaysia Coral Reef Conservation Project
(MCRCP) utilised the standard baseline survey techniques developed by CCC for the
rapid assessment of biological and physical characteristics of reef communities by
trained volunteer divers. Following an intensive training programme, CCC’s
techniques have been shown to generate precise and consistent data appropriate for
baseline mapping (Mumby et al., 1995). All surveys were co-ordinated by the PS and
SO to ensure accurate and efficient data collection.
CCC’s standard baseline transect survey technique utilises a series of plot-less
transects, perpendicular to the reef, starting from the 28 metre depth contour or four
meters below the bottom of reefal development, whichever is deeper. Surveys
terminate at the reef crest or in very shallow water. Benthic and fish surveys were
focused on life forms or families along with a pre-selected number of target species
that were abundant, easily identifiable or ecologically or commercially important.
Stony corals were recorded as life forms as described by English et al. (1997) and
selected corals were identified to species level. Fish were generally identified to
family level but in addition, important target species were identified. Sponges and
octocorals were recorded in various life form categories. Seaweeds were classified
into three groups (green, red and brown algae) and identified to a range of taxonomic
levels such as life form, genera or species.
Since most transects require two or more dives to complete, transect surveys were
usually divided up into sections (or ‘sub-transects’) with surveys of each sub-transect
carried out by a team of four trained divers divided into two buddy pairs (A and B) as
shown in Figure 2.2. At the start point of each sub-transect, Buddy Pair B remained
stationary with Diver 3 holding one end of a 10 m length of rope, whilst Buddy Pair A
swam away from them, navigating up or along the reef slope in a pre-determined
direction until the 10 m line connecting Diver 1 and 3 became taught. Buddy Pair A
then remained stationary whilst Buddy Pair B swam towards them. This process was
repeated until the end of the planned dive profile, when a surface marker buoy (SMB)
carried by Diver 2 was deployed to mark the end of that sub-transect. The SMB acted
as the start point for the next survey team and this process was repeated until the
entire transect was completed. The positions of the SMB at the start and end of each
dive were fixed using a Global Positioning System (GPS).
Diver 1 was responsible for leading the dive, taking a depth reading at the end of each
10m interval, and documenting signs of anthropogenic impact such as broken coral or
fishing nets. Diver 1 also described the substratum along the sub-transect by recording
the presence of six substrate categories (dead coral, recently killed coral, bedrock,
rubble, sand and mud). Divers 2, 3 and 4 surveyed fish, hard corals and algae, soft
corals, sponges and invertebrates respectively. Diver 3 surveyed an area of
approximately 1 metre to each side of the transect line whilst Divers 1, 2 and 4 survey
an area of approximately 2.5 metres to either side of the line.
17.
Methods
Direction of travel
(BUDDY PAIR A)
Diver 1
Diver 2
(Physical survey)
(Fish survey + SMB)
10m rope
(BUDDY PAIR B)
Figure 2.2.
Diver 3
Diver 4
(Hard coral survey)
(Algae, soft coral,
sponge & invertebrate survey)
Schematic diagram of a baseline survey dive team showing the positions and
data gathering responsibilities of all four divers. Details of the role of each
diver are given in the text.
During the course of each sub-transect survey, divers may have traversed two or more
apparently discrete habitat types, based upon obvious gross geomorphological (e.g.
forereef, escarpment or lagoon) or biological differences (e.g. dense coral reef, sand
or rubble; Figure 2.3). Data gathered from each habitat type were recorded separately
for subsequent analysis.
A
B
Start
End
Habitat 1
Figure 2.3.
Habitat 2
Habitat 3
Schematic diagram (aerial aspect) of an example of a reef area mapped by
divers during a sub-transect survey. Solid line represents imaginary subtransect line. Dashed lines and shaded areas represent areas surveyed (A =
5m wide swathe surveyed by Divers 1, 2 and 4; B = 2 m wide swathe
surveyed by Diver 3). Benthic data from habitats 1, 2 and 3 (e.g. reef, sand
and rubble) are recorded separately.
Each species, life form or substratum category within each habitat type encountered
was assigned an abundance rating from the ordinal scale shown in Table 2.2.
18.
Methods
Abundance rating
Coral and algae
0
1
2
3
4
5
None
Rare
Occasional
Frequent
Abundant
Dominant
Table 2.2.
Fish and invertebrates
(number of individuals)
0
1-5
6-20
21-50
51-250
250+
Ordinal scale assigned to life forms and target species during baseline surveys.
During the course of each survey, certain oceanographic data and observations on
obvious anthropogenic impacts and activities were recorded at depth by the divers and
from the surface support vessel. Water temperature readings (±0.5°C) were taken
from the survey boat using a bulb thermometer at the sea surface. The survey team
also took the temperature at the maximum survey depth (i.e. at the start of the survey).
Similarly, the salinity was recorded using a hydrometer and a water sample taken
from both the surface and the maximum survey depth. Water visibility, a surrogate of
turbidity (sediment load), was measured both vertically and horizontally. A secchi
disc was used on the survey boat to measure vertical visibility through the water
column (Figure 2.4). Secchi disc readings were not taken where the water was too
shallow to obtain a true reading. Horizontal visibility through the water column was
measured by divers’ estimates while underwater. Survey divers qualitatively assessed
the strength and direction of the current at each survey site. Direction was recorded as
one of eight compass points (direction current was flowing towards) and strength was
assessed as being ‘None’, ‘Weak’, ‘Medium’ or ‘Strong’. Similarly, volunteers on the
survey boat qualitatively assessed the strength and direction of the wind at each
survey site. Direction was recorded as one of eight compass points (direction wind
was blowing from) and strength was assessed using the Beaufort Scale.
Figure 2.4.
The use of a secchi disc to assesses vertical water clarity. The secchi disc is
lowered into the water until the black and white quarters are no longer
distinguishable. The length of rope from the surveyor to the disc is then
recorded. Source: English et al. (1997).
19.
Methods
Natural and anthropogenic impacts were assessed both at the surface from the survey
boat and by divers during each survey. Surface impacts were classified as ‘litter’,
‘sewage’, ‘driftwood’, ‘algae’, ‘fishing nets’ and ‘other’. Sub-surface impacts were
categorised as ‘litter’, ‘sewage’, ‘coral damage’, ‘lines and nets’, ‘sedimentation’,
‘coral disease’, ‘coral bleaching’, ‘fish traps’, ‘dynamite fishing’, ‘cyanide fishing’
and ‘other’. All information was assessed as present /absent and then converted to
binary data for analysis. Any boats seen during a survey were recorded, along with
information on the number of occupants and its activity. The activity of each boat was
categorised as ‘diving’, ‘fishing’, ‘pleasure’ or ‘commercial’. Finally the divers
recorded a general impression of the site during each survey. These ratings were
completed for biological (e.g. benthic and fish community diversity and abundance)
and aesthetic (e.g. topography) parameters. Both parameters were ranked from a scale
of 5 (excellent), 4 (very good), 3 (good), 2 (average) or 1 (poor).
Data collected from each sub-transect survey were transferred to recording forms
prior to incorporation into CCC’s database. The recording forms are shown in
Appendix I and consist of a ‘Boat Form’, ‘Physical Form’ and ‘Biological Form’.
Each form is completed for each individual dive, although there may be more than
one biological form depending on the number of habitats observed. The Boat Form
holds data on the GPS co-ordinates of the dive along with oceanographic and climate
data such as winds, currents, temperatures and salinities. The Physical Form holds
data on the maximum and minimum depths of the dive, the aesthetic and biological
ratings and also a reef profile drawn from the depths collected every 10 m. Finally the
Biological Form(s) contain data on the reef zone, the major biotic and substratum
features of the habitat and the ordinal ratings of each life form and target species.
2.4
Data analysis
2.4.1
Baseline data
Oceanographic, climate and anthropogenic impact data
Data on water temperature, salinity, visibility, the strength and direction of currents
and wind, natural and anthropogenic impacts, the presence of boats and the biological
and aesthetic ratings were summarised graphically and via univariate statistics, along
with more detailed examination of the data using Analysis of Variance (ANOVA) and
subsequent least significant difference multiple range tests. Data were either
summarised for the whole project area or for each of the five reef complexes as
appropriate.
Benthic data
In order to describe the reefal habitats within the project area, benthic and substratum
data were analysed using multivariate techniques within PRIMER (Plymouth
Routines in Multivariate Ecological Research) software (Clarke and Warwick, 1994).
Data from each Biological Form (which represents a ‘snap-shot’ of the benthic
community from either part or all of a habitat type distinguished by the survey team)
are referred to as a Site Record. Multivariate analysis can be used to cluster the Site
Records into several groups, which represent distinct habitats.
20.
Methods
During PRIMER analysis, firstly, the similarity between benthic assemblages at each
Site Record was measured quantitatively using the Bray-Curtis Similarity coefficient
without data transformation (Equation 1; Bray and Curtis, 1957). This coefficient has
been shown to be a particularly robust measure of ecological distance (Faith et al.,
1987).
Agglomerative hierarchical cluster analysis with group-average sorting was then used
to classify field data. Cluster analysis produces a dendrogram, grouping Site Records
together based on biological and substratum similarities. Site Records that group
together are assumed to constitute a distinct habitat. Characteristic species or substrata
of each class were determined using Similarity Percentage (SIMPER) analysis (Clarke
1993).
To identify characteristic features, SIMPER calculates the average Bray-Curtis
similarity between all pairs of intra-group samples (e.g. between all Site Records of
the first cluster). Since the Bray-Curtis similarity is the algebraic sum of contributions
from each species, the average similarity between Site Records of the first cluster can
be expressed in terms of the average contribution from each species. The standard
deviation provides a measure of how consistently a given species contributes to the
similarity between Site Records. A good characteristic species contributes heavily to
intra-habitat similarity and has a small standard deviation. The univariate summary
statistics of median abundance of each species, life form and substratum category
were also used to aid labelling and description of each habitat.
Finally, the habitat of each Site Record was combined with the geomorphological
class assigned during the survey to complete the habitat label. The combination of a
geomorphological class and habitat to produce a habitat label follows the format
described by Mumby and Harborne (1999).
Fish and invertebrate data
Fish and invertebrate data were summarised graphically and via univariate statistics,
along with more detailed examination of the data using ANalysis Of SIMilarity
(ANOSIM, a routine within PRIMER). ANOSIM tests for differences between groups
of community samples, defined a priori, using randomisation methods on a similarity
matrix produced by cluster analysis.
2.5
Management Rating
The concept of the establishment of a Marine Protected Area or Areas is based on the
need for environmental stability as well as the influence of socio-economic demands
placed on the natural resources of an area. This trade-off often results in the areas that
are declared as MPA’s being as geographically small as is possible whilst protecting
the marine resources of the entire region- a concept of representation. Ideally, MPA
sites should represent the best and most ecologically important areas. This idea is
related to the theory that certain reef areas are source reefs that have a net export of
larvae whilst other areas are sink reefs that have a net import of larvae. The concept
behind this source and sink reef management is that if the source reefs are protected,
they will repopulate the denuded sink reef areas.
21.
Methods
Source reefs are reefal areas of good health. The concept of a healthy coral reef
community is a complex one and one that relies on a number of variables. In this
study, the relative health and therefore the relative management potential of each
surveyed area of reef is defined using a range of univariate health indicators. Each of
these indicators is calculated for each habitat or habitat, which is in itself, a
geographically defined data set. The factors used were; mean hard coral cover,
Shannon-Weiner Diversity Index of benthic species associated with the habitat, the
number of benthic species recorded, Shannon-Weiner Diversity Index of fish
associated with the habitat in question, and the number of fish species recorded in the
habitat.
In order to examine the relative health, diversity and status of the coral reef around
Redang, an innovative method of calculation has been devised. The theoretical basis
behind the conservation management rating system is that areas of coral reef around
which Marine Protected Areas should be established to maximise their benefit should
be as biodiverse, productive and representative of all habitats. This technique
combines many of these variables based upon the classification of coral reef areas that
have been surveyed and subsequently classified into a habitat.
Once all survey records had been assigned to one of a discreet number of habitates,
further analysis based on these subsets of data was performed. The total number of
species and Shannon-Weiner diversity indices have been calculated on both the
benthic community as well as on the fish communities that were recorded by CCC
divers at the site of each Survey Record. Finally, values of average hard coral cover
from the detailed habitat descriptions for each habitat were also extracted. Average
values for each of these biological indicators of reef health were then calculated
across the entire data set.
To quantify the spatial distribution of areas of reef, each Survey Record was assigned
a rating from one to five. A score of zero on this rating scale equates to the Survey
Record belonging to a habitat or habitat where none of the five univariate reef health
indicator variables were above average across all the Survey Records analysed. By
contrast, a Survey Record with a score of five belongs to a habitat where all five
variables were above the average value calculated.
Each transect surveyed during the CCC Baseline technique is comprised of a
composite of more than one Survey Record, each of which may belong to different
habitates and therefore have differing degrees of reef health. By splitting each transect
into its constituent parts, and weighting the composition of each transect according to
the length surveyed, it was possible to construct an overall reef health statistic for that
survey transect ranging from 0-5. To facilitate easy interpretation of these values, the
following scale was used; where transects scored an overall rating >4.5 they were
classified as of high management potential, from 3.5-4.5 as moderate management
potential and finally below 3.5 of low management potential. With each of these
transects being spatially locatable data sets, a map to show the relative management
potential of each transect surveyed thus far has been constructed.
The resulting map illustrates point data sources but does not allow the overall
interpretation of conservation value of areas surrounding these transect points. To
22.
Methods
allow this, a unique mapping procedure was performed. The first stage in this
methodology was to produce a density grid over the survey area that illustrates the
density of the both transects and also the relative management value of these
transects. It was realised however that areas of high density could be as a result of
higher survey effort in a reef area and not as a result of high management potential
rating. To overcome this, another density grid of survey effort was created, the units
of which, although arbitrary, represent the number of transects per reef unit area.
Finally, by performing a calculation on the raster layers in a Geographic Information
System to divide the density grid of management value combined with survey effort
and the grid of survey effort alone, the output density grid is weighted for survey
effort and represents only the density of management value.
This output image was contained in a Geographic Information System that allows
users to query and delineate areas of high conservation and management value, to
calculate the geographic area comprising these sites and to add, for example, buffer
zones of a set distance around each of these sites of interest.
23.
Results
3.
RESULTS
3.1
Coral Reef Survey Progress
A total of two hundred and seventy eight CCC Baseline survey dives on seventy eight
transects were conducted in the period from March to September 2004. During these
dives, a total of 7.95 kilometres of reef were surveyed, collecting 24,777 records of
species and substratum abundance. The location of CCC baseline surveys completed
in Redang is depicted by Figure 3.1
All maps reproduced in this report have been digitised from a Landsat ETM+ image
acquired on 8th May 2001. The coordinate system used is the Universal Transverse
Mercator system of which the project site is within Zone 48 North. Maps are projected
on the World Geodetic System- 84 geographic spheroid (WGS84).
24.
Results
Figure 3.1.
Location of start points (red symbols) of Baseline Transects conducted by CCC around Redang Island between March and September 2004.
The data collected is presented in this report.
25.
Results
3.2
Oceanographic data
3.2.1
Wind speed and Direction
The mean wind strength during the survey period was 1.77 on the Beaufort scale. The
highest recordings made corresponded to five on the Beaufort scale and occurred
three times out of the 275 observations made. The prevailing wind direction was from
the south and south-east, with 44 of the observations originating from the south
(Figure 3.2).
N
25
20
W
NE
15
10
5
0
Weak
Moderate
SW
E
S
Figure 3.2.
3.2.2
Strong
SE
Radar diagram showing the prevailing winds recorded during MCRCP.
Points represent the frequency of occurrence of combinations of wind
direction and strength.
Salinity
The mean salinity value for all depths recorded during the CCC baseline surveys was
30.09 ‰ (n = 252, S.D. = 1.75‰). Overall there is a trend of increasing salinity with
increasing depth in the water column, to approximately 15m. A slight reduction in
salinity to 17m is followed with a sudden increase once more to approximately 23m
depth, where salinity levels again drop off (Figure 3.3). Lowest mean salinity values
were recorded in waters of approximately 27m.
26.
Results
PSU % o
28.5
0
29
29.5
30
30.5
31
31.5
5
Depth (m)
10
15
20
25
30
35
Figure 3.3.
3.2.3
Mean salinity recordings for all surveys in the project area in 5m depth
classes throughout the water column. Horizontal bars represent standard
deviations around the calculated mean. Sample sizes: 0m = 235; 0.1-5m = 27;
5.1-10m = 63; 10.1-15m = 59; 15.1-20m = 52; 20.1-25m = 36; 25.1-30m =
12; 31.5-35m = 1.
Water Temperature
A total of 545 temperature readings were recorded, both at surface and at the depth
where survey was conducted. The mean total temperature was 30.08o C (regardless of
depth). The temperature at the surface averaged the highest value, 30.9o C. A constant
decrease of temperature levels can be observed as depth increases. Temperature was
noted to stabilize deeper than 20o C. This can be explained by the presence of a
thermocline in some geographical areas of the bay, which may be associated with a
halocline (Fig 3.3). The average temperature above the halocline was 30.4o C,
compared with the 29.28o C averaged below the thermocline. Below the layer of the
thermocline, the temperature showed a more constant behaviour (20.1 – 25 m =
29.25o C; 25.1 – 30 m = 29.30o C).
27.
Results
Temperature OC
Depth of class mid point (m)
28
28.5
29
29.5
30
30.5
31
31.5
32
0
5
10
15
20
25
30
Figure 3.4.
3.2.4
Mean water temperatures for all surveys in the project area in 5 metre depth
classes throughout the water column. Horizontal bars represent standard
deviations around the calculated means. Sample sizes: 0 m = 269; 0.1 – 5 m =
34; 5.1 – 10 m = 69; 10.1- 15 m = 65; 15.1 – 20 = 56; 20.1 – 25 m = 39; 25.1
– 30 m = 13.
Current Strength and Direction
The most frequently observed currents during the MCRCP were classed as weak by
the survey divers, with 42.4% (n = 109) of the current observations in this category.
From the data collected there appears to be little or no overall pattern in terms of the
prevailing current direction in the survey area (Figure 3.5), with the greatest number
of records recording currents from the south (n = 44). The Redang Archipelago, being
situated on a shallow continental platform is exposed primarily to tidal currents.
28.
Results
N
30
NW
NE
20
Weak
10
Moderate
W
0
E
SW
Strong
SE
S
Figure 3.5.
3.2.5
Mean underwater current strength and direction recorded in the Redang
Archipelago during surveys. Points represent the frequency of occurrence of
combinations of current direction and strength. Symbols represent current
strength from weak to strong.
Underwater Visibility
Underwater visibility was observed in two ways during the MCRCP. Firstly the
vertical visibility through the water column was measured with the use of a Secchi
disc as described in the methods section. Dive teams at the deepest points of the
survey also estimated horizontal visibility. Whilst the recordings made from these two
measures are often closely correlated, fluctuations in the visibility at different depth
ranges in the water column such as those produced within an area of a thermocline
may cause a significant difference in the readings. Both sets of data are presented
graphically in Figures 3.6 and 3.7.
Mean vertical visibility of 15m or greater as recorded by Secchi disc was recorded at
three sites TK, TL and DK, (Figure 3.6). The sites with the lowest mean visibility and
therefore the highest turbidity were PK, MS and PB.
29.
Mean Secchi Disc reading (m)
Results
25
20
15
10
5
0
DK ET KB LM LT MS PB PI PK PP PT TA TK TL TN
Survey Sector
Figure 3.6.
Mean Secchi Disc recordings of vertical visibility in metres (± S.D.) for each
survey sector
Mean Horizontal visability (m)
25
20
15
10
5
0
DK ET KB LM LT MS PB
PI
PK PP PT TA TK TL TN
Survey Sector
Figure 3.7.
Mean horizontal visibility recordings by divers in metres (± S.D.) for each
survey sector.
Mean horizontal visibility peaked at sector TL at 18m. Under water visibility was
generally good with seven of the fifteen sites recording mean horizontal visibility of
15 or greater.
30.
Results
3.3
Anthropogenic data
3.3.1
Boat Activity
4
3.5
3
2.5
2
1.5
1
0.5
TL
TN
PT
TA
TK
LT
M
S
PB
PI
PK
PP
0
DK
ET
KB
LM
Mean number of boats seen within 1km of
survey site per visit
Both the number and type of boat observed in a surveyed area gives an indication of
the origin of impacts that may be affecting a coral reef environment. A summary of
observations recorded for boat activity during the MCRCP is presented in Figures 3.8
and 3.9. Overall, 397 boat were observed during 275 visits. PT, around the main jetty
allowing access to the village had the greatest boat traffic of all sectors, with an
average of 3.7 boats observed within 1 km per visit (Fig. 3.8). LM recorded the
second highest value of boat traffic (2.6 boats within 1 km per visit). Less than 2 boats
per visits were observed at the rest of the sectors. 67% of all observed boats were
engaged in tourism activities (pleasure and diving). This high value is not surprising
given the large number of resorts on the Islands. However, it is interesting to note that
pleasure had a much higher occurrence (59%) than diving (8%).
Survey Sector
Figure 3.8.
Mean frequency of boat sightings within 1 km of survey sites for each survey
sector.
31.
Results
100%
90%
Frequency (%)
80%
70%
DIVING
60%
COMMERCIAL
50%
FISHING
40%
PLEASURE
30%
20%
10%
PT
TA
TK
TL
TN
PI
PK
PP
LT
MS
PB
DK
ET
KB
LM
0%
Survey Sector
Figure 3.9.
Percentage boat activity recorded within each survey sector.
Sample sizes; TK=41, ET=5, KB=26, LM=18, LT=4, MS=4,
PB=61, PI=10, PK=9, PP=16, PT=52, TA=25, TK=37, TL=51, TN=38.
Fishing vessels were those engaged in fishing at the time of the observation, i.e. with
onboard personnel actively fishing and not in transit. Fishing boats were observed in
greater number in ET and PP. Within commercial activities were classified those
fishing boats arriving and departing the villages and boats used to supply both
personnel and provisions sold locally to the tourist resorts. Boats observed at survey
sector LT were solely undertaking commercial activities
3.3.2
Surface and Subsurface Impacts
Environmental impacts to the surface and sub-surface water environment were
recorded during surveys and have been presented in Figures 3.10 and 3.11
respectively. Surface water impacts were observed in all survey sectors, with the
exception of sector ET. Litter was the commonest impact, on the remaining fourteen
sectors with recordings made on approximately 5-15% of surveys. The highest levels
of litter were observed in sector PT, with recordings made on 50% of surveys.
Generally speaking, the remaining surface water impacts were distributed over a
smaller spatial range and were found confined to one or two survey sectors. For
example, discarded fishing nets were found only in sectors PK and TA. Similarly,
sewage was recorded in sector PP and PI only. The nature of surface water impacts
varied, with ‘Other’ impacts, such as dead fish and discarded fishing apparatus noted
on six of the fifteen survey sectors.
32.
Results
Frequency of Surface Impacts
60%
50%
Litter
40%
Sewage
Driftwood
30%
Algea
Nets
20%
Other
10%
0%
DK
ET
KB
LM
LT
MS
PB
PI
PK
PP
PT
TA
TK
TL
TN
Survey Sector
Figure 3.10.
Percent frequency of the occurrence of surface impacts within each survey
sector.
In comparison to surface impacts, a greater number of sub-surface water impacts were
noted during surveys. Where impacts were present, they tended to occur on a higher
percentage of surveys
40%
Frequency of Sub-surface Impacts
35%
Litter
30%
Sewage
25%
Coral Damage
Lines and Nets
Fish Traps and Pots
Sedimentation
20%
Disease
Bleaching
15%
Dynamite
Other
10%
5%
TN
TL
TK
TA
PT
PP
PK
PI
PB
MS
LT
LM
KB
ET
DK
0%
Survey Sectors
Figure 3.11.
Percent frequency of occurrence of sub-surface impacts within each survey
sector
33.
Results
3.3.3
Aesthetic and Biological Impressions
Survey diver impressions of the aesthetic and biological quality of the coral reef have
been presented in Figure 3.12. While such data is, by its nature, subjective, such
information can provide a useful indication of the overall condition of the reef within
a particular area. As might be expected Figure 3.12 shows there is clearly a
relationship between the divers’ aesthetic and biological impressions of the reef, such
consistency supports the validity of the data. The reef areas in sectors DK, PT, TK,
TL, TN were observed to be of relatively high quality, with the aesthetic and
biological impressions on 5-15% of surveys recorded as ‘Excellent’. In contrast
sectors LT and PI were found to be the lowest aesthetic and biological quality, with
diver impressions of the reef on approximately 40% of reefs. Generally speaking, the
quality of the reef within each sectors varied, with survey impressions encompassing
all five ratings from ‘poor’ to ‘excellent’. An exception to this was sector ET that
recorded only two ratings during surveys (60% of which recorded as average and 40%
recorded as good). This suggests the quality of the reef to be relatively consistent
within those areas.
80%
Excellent
Very Good
60%
Good
40%
Average
Poor
20%
0%
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Aesthetic
Biological
Rating
Percentage Recorded of Each
100%
DK
ET
KB
LM
LT
MS
PB
PI
PK
PP
PT
TA
TK
TL
TN
Survey Sector
Figure 3.12
Diver impressions of the aesthetic and biological value of sites surveyed
within each sector.
34.
Results
3.4
Multivariate Analysis and Habitat Definitions
The following section presents the dendrogram produced by agglomerative hierarchal
cluster analysis as outlined in the methods section (Figure 313.). Secondly, using the
characteristics of the habitates as defined by SIMPER and univariate analysis; a full
and quantitative description of each habitat identified is presented in Table 3.1.
It is hoped that this report, which outlines the multivariate defined habitats found in
the coral reef communities around Redang, will be used to form a wider resource map
of the archipelago. Plans for a collaborative venture between CCC and the Malaysian
Centre of Remote Sensing (MACRES) are in the approval stages at the time of the
writing of this report. Collaboration will allow the overlaying of the field data
presented in this report with high-resolution satellite imagery to produce detailed coral
reef resource maps.
3.4.1
Habitat Descriptions
In total, fourteen statistically discreet habitat types or habitats have been defined from
data collected around the Redang Islands. A quantitative description of each of these
habitats is given in table 3.1. The values shown in parenthesis in these tables indicate
the mean abundance of each variable seen in the habitat in question on the 1-5
DAFOR scale.
Of the habitats seen, two were classified as being found at the shallow reef crest (<2m
depth), five as upper reef slope (<5m depth), six as mid to lower reef slope (5-14m
depth) and one as lower reef slope (>14m depth). Habitat 5, classified as upper reef
slope areas with high live hard coral cover dominated by branching Acropora and
dead coral with algae had the highest live hard coral cover of 3.6% of all the habitats
found. Amongst the shallow habitats, the dominant coral cover was of the branching
Acropora life form, comprising over 75% in many of the habitats. With increasing
depth, the Acropora branching corals were out competed by Non-Acropora encrusting
and massive life forms that became dominant in habitats encountered at an average
depth below 9 meters.
Notes on Statistics
When used in the presentation of statistical data, P-values denote the probability of
an observation occurring by chance alone. A P-value of <0.05 indicates that the
observation would have happened by chance alone on only 5 or less times in 100
repetitions. A p-value of <0.05 is therefore an indicator that some factor other than
the probability of chance is producing the data. It is therefore considered to be
significantly different if the p-value is greater than, or equal to 0.05.
Other statistical conventions used in the report are the χ2 that refers to the Chisquared value calculated during this test; the T-value calculated during the MannWhitney test on non-parametric and non-normalised data; and the R-value calculated
during multivariate analysis comparing two or more populations of data.
35.
Results
Figure 3.13.
Dendrogram derived from cluster analysis of CCC baseline survey data
collected during the Redang Island Project. Each line represents benthic and
substratum data from each Site Record. The different colours highlight the
major clusters representing the habitats discriminated. Horizontal axis
represents similarity as calculated with the Bray- Curtis coefficient (%). A
total of 795 discreet ten-meter sections of reef are included in the data set
used to define the habitat or habitats present
36.
Results
Habitat
#
surveys
Mean
depth
Substratum
Hard Corals
Octocorals
Invertebrates
Sponges
Algae/ Seagrass
1 Sand dominated mid reef
slope
56
10.7
Sand (4.8)
Total cover (0.1)
Total cover
(0.1)
Total cover
(0.3)
2 Lower reef slope with
patchy deep water corals
64
20.4
Sand (2.4),
Bedrock (2.0)
Total cover
(1.6), Sinularia
(1.3),
Sarcophyton
(1.0)
Total cover (0.7), BlueGreen algae (0.4), Green
filamentous algae (0.2)
Schizothrix (2.0), Brown
filamentous (0.3), Red
filamentous (0.2),
Halophila seagrass (0.2)
3 Sand and rubble
dominated mid reef slope
47
10.4
Sand (2.3),
Rubble (2.3)
4 Frequently encountered
mid to upper reef slope
bedrock areas supporting
diverse live hard coral
communities
277
8.9
Bedrock (2.5),
Rubble (1.3),
Sand (1.1)
5 Upper reef slope areas
with high live hard coral
cover dominated by
Acropora and dead coral
with algae
91
4.3
Dead coral
with algae
(1.2), Rubble
(1.0),
Total cover (1.4), NonAcropora massive (0.9),
Non-Acropora Encrusting
(0.9), Favia sp. (0.9),
Favites, (0.8), Porites
massive (0.7), Galaxea (0.5)
Total cover (1.7), Acropora
branching (0.9), NonAcropora branching (0.9),
Non-Acropora massive
(0.9), Non-Acropora
mushroom (0.5), Porites
massive (1.0), Pocillopora
damicornis (0.9), Favia (0.8)
branching (1.3), NonAcropora encrusting (1.3),
Non-Acropora massive
(1.2), Echinopora horrida
(0.7), Favia (0.9), Favites
(0.9), Montipora foliosa
(0.7)
branching (2.4), NonAcropora branching (1.0),
Non-Acropora mushroom
(1.0), Acropora tabulate
(0.7), Bottlebrush Acropora
(0.7),
Total cover (0.7),
Synaptid sea
cucumber (0.5)
Total cover (1.0),
Table 3.1.
Total cover
(0.2), Lumpy
(0.1)
Total cover
(0.6),
Sarcophyton
(0.4), Sinularia
(0.3), Anemone
(0.2)
Total cover (1.3),
Synaptid sea
cucumber (1.3),
Crinoid Featherstar
(0.2)
Total cover
(1.0), Lumpy
(0.9)
Total cover (1.1),
Lobophora (0.7), Red
encrusting (0.4), Green
filamentous (0.6), Brown
filamentous (0.4)
Total cover
(1.0), Sinularia
(0.9),
Sarcophyton
(0.4)
Total cover (1.5),
Christmas tree
worm (1.0),
Hydroid (0.6)
Total cover
(1.1), Lumpy
sponge (1.0)
Total cover (1.4),
Lobophora (1.0), Red
encrusting algae (0.7),
Green filamentous (0.6),
Schizotrix (0.5)
Total cover
(0.1)
Total cover (1.0),
Christmas tree
worm (0.7),
Diadema urchin
(0.3)
Total cover
(0.7), Lumpy
(0.7)
Total cover (1.8), Dictyota
(0.8), Lobophora (0.7),
Halimeda (0.6), Schizotrix
(0.6), Green filamentous
(0.5)
Quantitative description of the fourteen habitats defined from the data collected in the Redang Islands. Figures in parenthesis
indicate mean observational abundances from the DAFOR (0-5) semi-quantitative scale as used during CCC Baseline surveys
37.
Results
Habitat
#
surveys
Mean
depth
Substratum
Hard Corals
Octocorals
Invertebrates
Sponges
Algae/ Seagrass
6. Sheltered reef crest
areas dominated by foliose
and branching nonAcropora corals
15
2.6
Sand (1.3),
Bedrock (1.2),
Rubble (1.1)
Total cover
(0.1)
Total cover (0.9),
Synaptid sea
cucumber (0.7)
Total cover
(0.5),
Encrusting
(0.4)
Total cover (1.7), Green
filamentous (1.2), Jania
(0.4)
7 Upper reef slope with
bedrock and dead coral
with algae; live coral
community dominated by
branching Acropora
8 Mid reef slope bare
bedrock and mixed live
hard coral cover
29
4.8
Bedrock (2.2),
Dead coral with
algae (1.3),
Rubble (1.2)
Total cover
(0.1)
Total cover (2.2),
Zoanthids (2.6),
Tunicates (0.5),
Total cover
(1.0), lumpy
(1.0)
Total cover (1.6),
Lobophora (1.0) Brown
filamentous (0.9),
26
7.1
Total cover
(0.8)
Total cover (1.3)
Christmas tree
worm (1.0),
Hydroid (0.2)
Total cover
(0.9), lumpy
(0.7)
Total cover (2.1)
9 Sand dominated lower
reef slope
29
14.0
Bedrock (2.0),
Dead coral and
algae (0.6),
rubble (1.5),
sand (0.9)
Dead coral with
algae (0.4),
Rubble (0.9),
Sand (4.8)
Total cover
(0.8), lumpy
(0.8)
Total cover (0.9),
Schizothrix sp (0.4),
Brown Filamentous (0.4),
Corallina (0.4)
7
6.7
Total cover
(0.6), Dead
man’s fingers
(0.3), leathery
(0.45)
Total cover
(1.0), Anemone
coral, (0.43)
Total cover (0.9),
Hydroid (0.3),
Synapta maculata
(0.9)
10. Upper reef slope algae
and sand dominated areas
with sparse live hard coral
coverage
Total cover (2.8), NonAcropora foliose (1.4),
Non-Acropora branching
(1.0), Acropora tabulate
(0.9), Acropora branching
(0.8), Porites nigrescens
(0.9), Symphyllia (0.6),
Montipora foliose (1.3),
Pocillopora damicornis
(0.9)
branching (2.0), Non
Acropora branching (0.5),
Non Acropora Encrusting
(0.4)
Encrusting (1.0), Non
Acropora foliose (0.8), Non
Non Acroproa Encrusting
(0.8)
Total cover (1.0), Non
Acropora Massive (0.5),
Non Acropora Encrusting
(0.4), Favites (0.2), Porities
Massive (0.7)
Acroproa Encrusting (9.0),
Porites Massive (0.7) Non
Favia (0.6), Favites (0.6),
Platgyra daetelea (0.6)
Total cover (2.0),
Synapta maculata
(1.4), Clam (0.4)
Nudibranch (0.4),
Zoanthids (0.4)
Total cover
(1.0), Lumpy
(0.6)
Total cover (2.9), Brown
Filamentous (1.9),
Green filamentous (0.9)
Sand (2.4),
Rubble (2.0),
Bed rock (1.6)
Table 3.1 (Continued). Quantitative description of the fourteen habitats defined from the data collected in the Redang Islands. Figures in parenthesis
38.
Results
Habitat
#
surveys
Mean
depth
Substratum
Hard Corals
Octocorals
Invertebrates
Sponges
Algae/ Seagrass
11 Sand and rubble
dominated reef crest
45
3.0
Sand (2.1),
Rubble (2.1),
Bed rock (1.6),
Non Acropora Branching
(0.8), Favites (0.7)
Total cover
(1.0)
8
11.2
Acropora branching (0.8),
Pocillopora small (0.7)
Total cover
(0.5), Dead
man’s fingers
(0.6)
Total cover (1.0), Green
filamentous (0.5),
13 Sheltered mid to lower
reef slope with sand and
rubble and sparse, diffuse
solitary mushroom corals
22
12.7
Sand (3.5),
Mud (1.5),
Dead coral with
algae (1.4),
Dead coral
(1.1),
Sand (2.1),
Rubble (1.5),
Dead coral and
algae (1.0)
Total cover
(0.6),
Encrusting
(0.4), Lumpy
(0.4)
Total cover
(0.6), Lumpy
(0.6)
Total cover (1.5) Green
filamentous (1.3),
Corallina (0.7)
12 Sheltered mid to lower
reef slope dominated by
blue green algae
colonising sand and mud
Total cover (1.6),
Sea cucumber
(0.3), Clam (0.2)
Synapta maculata
(1.7)
Total cover (0.8),
Feather star (0.9),
sea cucumber (0.5),
Zoanthid (0.5)
Total cover
(0.7), Leathery
(0.7)
Total cover (0.1)
Synapta maculata
(0.6), Zoanthids
(0.6)
Total cover
(1.2), Lumpy
(1.1),
Encrusting
(0.4)
Total cover (1.9),
Corallina (0.7), Brown
Filamentous (0.6),
Pandina (0.5)
14 Upper reef slope and
reef crest with moderate
and patchy low diversity
live hard coral cover with
sandy areas in between
11
5.6
Acropora mushroom (1.7),
Upside down bowl (1.2),
Ctenactis echinata (1.0),
Pocillopora small (0.9),
Non Acropora Branching
(0.6), favia (0.6)
Acropora Encrusting (1.1)
Total cover
(1.2), Dead
man’s fingers
(1.1)
Total cover (0.9),
Clam (0.6)
Total cover
(0.9), Lumpy
(0.8)
Total cover (1.0),
Lobophora (1.0),
Sand (1.9), Bed
rock (1.3),
Table 3.1 (Continued). Quantitative description of the fourteen habitats defined from the data collected in the Redang Islands. Figures in parenthesis
39.
Results
3.4.2
Univariate Measures of Habitat Biodiversity
Table 3.2 represents a range of univariate measures of coral reef biodiversity based on
the Site Records of benthic and sessile organisms that have been defined as belonging
to each habitat.
Three habitats stand out as having the highest number of species identified from the
target species list employed in the CCC Baseline transects; habitats 4, 5 and 2 which
have 148, 116 and 114 species respectively in the dataset. Habitat four has by far the
highest cover of benthic organisms as represented by the sum of the live benthic cover
on the semi-quantitative DAFOR scale (49.5), whilst habitat one is clearly a habitat
dominated by abiotic or substrate cover with little live benthic cover.
Perhaps the single most widely accepted biodiversity measure is the Shannon-Weiner
Index as it accounts for both the species diversity as well as the evenness of the
population structure. Habitats four and two have the highest overall Shannon-Weiner
diversity rating, with values of 4.26 and 4.10 respectively. Habitat five, whilst having
a high number of benthic species associated with it, does not however have one of the
highest overall Shannon-Weiner diversity indices (4.03) when compared to some of
the other habitats that had lower species numbers (e.g. Habitat three that has a
calculated Shannon-Weiner index of 4.06 and a number of observed species of 108).
Habitat
1
2
Mean
cover of
Live Hard
Sum of live
Loge
benthic cover ShannonCoral
(DAFOR
Weiner
(DAFOR
Number of
scale)
Species
scale)
Diversity
52
10.63
2.41
0.11
114
37.00
4.10
1.42
3
4
5
6
108
148
116
66
36.15
49.47
38.88
30.53
4.06
4.26
4.03
3.73
1.66
2.85
3.56
2.80
7
8
9
10
85
12
76
48
37.59
13.08
21.48
32.43
3.83
2.20
3.48
3.50
2.41
2.50
0.97
1.29
11
12
13
14
73
63
76
56
24.58
33.63
33.55
32.45
3.45
3.67
3.80
3.67
1.36
1.13
2.00
2.36
Table 3.2. Univariate biodiversity measures of the fourteen Habitats derived from Cluster
Analysis from data collected during the Redang Island phase of the MCRCP.
40.
Results
3.5
Fish Populations
The mean abundance values of the major reef fish taxa observed during the MCRCP
are depicted in Table 3.3. Mean abundances were derived from abundance ratings for
individual species using the semi-quantitative 0-5 DAFOR scale. During CCC
surveys, the most commonly observed fish family was Wrasse (Labridae), with a
mean abundance of 0.29. Damselfish (Pomacentridae) and Fusilier species
(Caesionidae) also shared a relatively high abundance of 0.21.
Fish taxa with the lowest mean abundances were Triggerfish (Balistidae), and Filefish
(Monacanthidae) with a shared abundance of 0.01. With the exception of Goby
species (Gobiidae) and Chromis species (Pomacentridae) (mean abundance: 0.14 and
0.13 respectively), the remaining fish taxa had relatively low mean abundance ratings,
ranging from 0.02-0.10.
It should be noted that the mean abundances of some species had relatively high
Standard Deviations (SD), indicating that these observations were extremely
heterogeneous in nature and were varied both in the frequency and the abundance of
reef fish in each individual observation.
Fish Taxa
Wrasse sp_
Damselfish sp.
Fusilier sp.
Parrot fish sp.
Goby sp.
Chromis sp.
Spine cheek sp.
Cardinalfish sp.
Snapper sp.
Butterfly fish sp.
Grouper sp.
Rabbit fish sp.
Angelfish sp.
Anthias sp.
Goat fish sp.
Filefish sp.
Triggerfish sp.
Latin name
Labridae
Pomacentridae
Caesionidae
Scaridae
Gobiidae
Pomacentridae
Nemipteridae
Apogonidae
Lutjanidae
Chaetodontidae
Serranidae
Siganidae
Pomacanthidae
Serranidae
Mullidae
Monacanthidae
Balistidae
Mean Abundance
0.29
0.21
0.21
0.20
0.14
0.13
0.09
0.05
0.05
0.04
0.04
0.04
0.03
0.02
0.02
0.01
0.01
S.D
0.52
0.65
0.68
0.48
0.27
0.50
0.27
0.24
0.21
0.17
0.17
0.19
0.14
0.15
0.10
0.01
0.04
Table 3.3. Calculated mean abundance ratings assigned to each major fish family (or
subfamily for Serranids) during CCC Baseline surveys of the MCRCP.
Mean values ± SD given correct to 2 Decimal places (D.P).
41.
Results
3.5.1
Fish Assemblage variation between Survey Sector
Lutjanids
Siganids
Chaetodontids
Labrids
Pomacentrids
Scarids
0.6
Abundance
0.5
0.4
0.3
0.2
0.1
0
DK ET KB LM LT MS PB PI PK PP PT TA TK TL TN
Survey Sector
Figure 3.14.
Commonly encountered fish families in each survey sector. Mean abundance
refers to the values recorded on the 0-5 DAFOR semi-quantitative abundance
scale. See Figure 3.1 for survey sector locations
Ballistids
Mullids
Pomacanthids
Serranids
0.1
0.09
Abundance
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
TN
TL
TK
TA
PT
PP
PK
PI
PB
MS
LT
LM
KB
ET
DK
0
Survey Sector
Figure 3.15.
Less frequently encountered fish families in each survey sector. Mean
abundance refers to the values recorded on the 0-5 DAFOR semi-quantitative
abundance scale. See Figure 3.1 for survey sector locations.
The most abundant encountered fish families per survey sector are shown in figure
3.14. The three most common families are Scarids, Pomacentrids and Labrids, which
42.
Results
were abundant in all survey sectors. The most highly represented family is Scarids
which were particularly abundant in sectors PP, TL, KB, LM and LT, The second
most commonly encountered fish family is Pomacentrids which were mostly seen in
sectors DK, MS and TL. Lutjanids were totally absent from sectors KB, LT and PK.
Of the less frequently encountered fish families per survey sector (figure 3.15)
Pomacanthids and Serranids were most abundant with Serranids present at all survey
sectors and Pomacanthids present at all except sectors ET and LT.
3.5.2
Fish Assemblage variation between habitat types
Out of the 728 individual areas of reef that were surveyed in Redang and included in
this report, sixty-two had no fish recorded. Of these, by far the majority (72% of the
records) were classified as being habitat one - the sand dominated mid-reef slope that
owing to its ecological simplicity does not constitute the number of ecological niches
capable of supporting a diverse and abundant fish assemblage. These sixty-two
records were removed from the data set for further analysis.
The abundance of fish families found associated with each of the habitats defined by
multivariate analysis and outlined in section 3.4.1 are graphically represented in
figures 3.16 –3.17.
Chaetodontids
Siganids
Lutjanids
Scarids
Labrids
Pomacentrids
0.7
Abundance
0.6
0.5
0.4
0.3
0.2
0.1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Habitat Type
Figure 3.16.
Mean abundance of more frequently observed fish families found associated
with each habitat. Mean abundance refers to the values recorded on the 0-5
DAFOR semi-quantitative abundance scale.
43.
Results
Balistids
Mullids
Pomacanthids
Serranids
0.14
Abundance
0.12
0.1
0.08
0.06
0.04
0.02
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Habitat Type
Figure 3.17.
Mean abundance of less frequently observed fish families found associated
with each habitat. Mean abundance refers to the values recorded on the 0-5
DAFOR semi-quantitative abundance scale.
The overall most abundant and ubiquitous fish family observed across all habitat
types defined were the Damselfish (Pomacentridae). Whilst there was variation
observed in the abundance of Pomacentrids between habitat types, their abundance
did not fall below 0.07 in any single habitat. The abundance of Scarids (Parrotfish)
varied widely between habitat types. They were the most abundant fish type seen
overall in habitat 6, with an average abundance of 0.66 whilst they were nearly absent
in habitat thirteen Habitat six has been identified as the sheltered reef crest areas,
whereas habitat was identified as a sheltered mid to lower reef slope dominated by
depositional substrates which by their definition do not have the varied food source
available for the algal grazing and coralivorous Parrotfish.
Wrasse (Labridae) were found ubiquitously associated with all the habitats identified.
Variation in the population structure of the less commonly observed fish families was
much greater than amongst the more commonly observed taxa. Overall rarer fish taxa
are likely to be more habitat dependent. For example, the Mullids (Goatfish) were
observed in high abundance associated with the sand and soft substrate dominated
habitats twelve and fourteen. This relates to the feeding methods employed by species
in this family, which rely on the infaunal invertebrate populations found in soft
sediment substrates.
44.
Results
Table 3.4 shows the statistical relationship between fish assemblages found associated
with each of the habitat types identified. The values in the table indicate the results of
a multivariate pair-wise analysis between fish assemblages and values in bold marked
with an asterisk indicate that there is a significant difference between the composition
of these fish assemblages.
2
3
4
5
6
7
8
9
10
11
12
13
14
1
0.29
0.001*
0.24
0.001*
0.71
0.001*
0.62
0.001*
0.01
0.46
0.22
0.001*
0.03
0.395
-0.04
0.927
-0.02
0.563
0.19
0.001*
0.12
0.066
0.09
0.018*
-0.04
0.707
2
0.05
0.018*
0.34
0.001*
0.33
0.001*
0.04
0.277
0.06
0.108
0.26
0.13
0.26
0.001*
0.03
0.418
0.15
0.001*
0.36
0.001*
0.27
0.001*
0.01
0.538
3
0.28
0.001*
0.26
0.001*
-0.01
0.492
0.03
0.199
0.21
0.098
0.21
0.001*
-0.07
0.682
0.24
0.001*
0.26
0.018*
0.18
0.004*
-0.12
0.903
4
0.02
0.287
0.19
0.019*
0.01
0.45
0.42
0.003*
0.60
0.001*
0.14
0.128
0.39
0.001*
0.63
0.001*
0.54
0.001*
0.11
0.153
5
0.02
0.006*
0.03
0.265
0.47
0.011*
0.60
0.001*
0.17
0.001*
0.44
0.001*
0.65
0.001*
0.54
0.001*
0.22
0.018*
6
0.49
0.001*
0.40
0.023*
0.04
0.223
0.22
0.044*
0.29
0.002*
0.54
0.001*
0.05
0.176
0.19
0.001*
7
0.67
0.001*
0.37
0.001*
0.33
0.009*
0.26
0.001*
0.78
0.001*
0.36
0.001*
0.45
0.001*
8
0.11
0.18
-0.02
0.448
0.42
0.017*
0.18
0.135
-0.01
0.461
0.36
0.035*
9
-0.01
0.512
0.31
0.001*
0.16
0.035*
0.12
0.007*
0.01
0.432
10
0.32
0.019*
0.04
0.303
-0.16
0.937
0.03
0.313
11
0.67
0.001*
0.38
0.001*
0.3
0.004*
12
-0.02
0.557
0.48
0.001*
Table 3.4. Pair wise multivariate comparison between fish assemblages associated with
each habitat.
Note: Values in normal font indicates the calculated R-value correct to 2 D.P.;
values in bold indicate P-values correct to 3 D.P. P-values marked with an
asterisk indicate a significant difference in the fish assemblages found associated
with the two habitats concerned.
Examination of table 3.4 indicates that of the fish assemblages identified being found
associated with the habitat types, those found associated with habitat number five are
similar only to those of habitat four and seven. Compared to the remaining fish
assemblages, those found in habitat five are statistically significantly different.
Referring back to the habitat definitions, habitat five, four and seven are all diverse
live hard coral dominated habitats. Accordingly, with the provision of a high number
of ecological niches, these fish assemblages are more biodiverse and include for
example, a higher than average abundance of Pomacanthids (Angelfish - see figure
3.16).
45.
13
-0.09
0.896
Results
The number of reef fish species recorded and associated biodiversity indices for each
habitat are depicted in Table 3.5. The greatest recorded species number was found
within the fish assemblage associated with habitat twelve. By contrast, only six fish
species were recorded in areas of habitat one. In terms of the overall abundance of
reef fish habitat twelve had only a moderate density of fish found associated with it,
whilst habitats eleven, seven and eight had sum abundance ratings of 22, 21 and 21
respectively. This is reflected in the Pielous evenness statistic which for habitat twelve
is only 0.81 and is 0.87, 0.92 and 0.83 for habitats seven, eight and eleven
respectively. Finally, the Shannon-Weiner diversity index which is often used as the
best rating of overall biodiversity indicates that habitat eight revealed the most diverse
fish assemblage associated with it. Habitats twelve and six having slightly lower
overall diversity with calculated diversity indices of 3.85 and 3.83 respectively.
Habitat
Species
Number
Sum of
abundance
ratings
Marglef Index
of species
richness
Pielous
Evenness
Index
Loge
Simpsons
Shannon- Diversity
Weiner
Index
1
30
4
22.02
0.84
2.85
1.26
2
3
4
5
6
7
8
9
63
59
105
68
42
41
19
43
12
15
16
15
15
13
2
7
25.37
21.36
37.35
24.57
15.14
15.78
32.81
21.37
0.78
0.80
0.70
0.75
0.83
0.75
0.93
0.85
3.22
3.25
3.26
3.16
3.12
2.78
2.74
3.19
1.02
1.00
0.99
0.99
1.00
0.97
2.18
1.09
10
11
12
13
14
25
41
30
41
42
13
7
13
8
17
9.44
20.69
11.39
18.79
14.47
0.88
0.79
0.90
0.86
0.84
2.83
2.95
3.08
3.19
3.13
1.00
1.06
1.02
1.06
0.99
Table 3.5. Univariate biodiversity measures calculated for fish assemblages found
associated with each habitat defined from data on benthic populations presented
in this study. Species number and sum of abundance ratings are given as
integers; calculated diversity indices are given correct to 2 D.P.
3.6
Invertebrate Populations
Abundance ratings for invertebrate species were recorded during CCC survey dives,
using the semi-quantitative 0-5 DAFOR scale. The mean abundance of selected
invertebrate taxonomic groups is shown in Table 3.6. Sea Cucumbers were observed
to have the highest overall abundance. With a value of 0.41 their abundance was over
twice that of the second most abundant groups, Annelids and Tunicates (with a shared
abundance of 0.18). Holothurians and Cephalopods were not observed on surveys
undertaken by CCC. The remaining groups had relatively low abundances, ranging
from 0.01 to 0.11. The presence of Crinoid featherstars and Crown of Thorn Seastars
46.
Results
(Acanthaster plancii) have been assessed individually at the species level because of
their abundance and corallivorous nature respectively. All of the calculated mean
values contain large variance (S.D.) indicating that the distribution of the invertebrate
taxa identified is heterogeneous between geographic areas.
Taxa
Sea Cucumbers
Annelids
Tunicates
Crinoid Featherstar
Bivalve
Urchins
Crown of Thorns (Acanthaster planci)
Gastropods
Crustaceans
Seastar
Cephalopods
Mean Abundance
0.41
0.18
0.18
0.12
0.11
0.08
0.04
0.03
0.02
0.01
0.00
Standard Deviation
0.65
0.48
0.39
0.32
0.32
0.26
0.14
0.17
0.08
0.10
0.01
Table 3.6. Calculated mean abundance ratings assigned to each major invertebrate taxa
during CCC Baseline survey dives during the MCRCP. Mean values ± SD given
correct to 2 D.P.
3.6.1
Invertebrate Populations by Survey Sector
Figures 3.18 and 3.19 depict the mean abundances of observed invertebrate
populations within each survey sector for the more commonly (Fig. 3.18) and less
frequently observed (Fig. 3.19) invertebrate taxa.
Amongst the more frequently observed invertebrate taxa, sea cucumbers and Annelids
show the most heterogeneous geographic distribution. They were most commonly
found within Survey Sector LT with an abundance rating of over 0.8 and 0.38
respectively. Crinoid Feather stars have a much more even distribution, but peaked in
survey sector MS, with a standard deviation of 0.65 around a mean abundance across
all areas of 0.38.
Amongst the less frequently observed invertebrates, Cephalopods have the most
notable patchiness to their distribution, being only observed in sectors PB and PI.
Holothurians were however notably only observed within sector TN, with a mean
abundance of 0.18. Acanthaster planci (Crown of thorns) was observed in eleven of
the fifteen survey sectors with the highest mean abundance of 1.5 in survey sector
MS.
47.
Results
Urchins
Bivalves
Crinoid Featherstars
Annelids
Tunicates
Sea Cucumbers
1
0.9
0.8
Average Abundance
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
DK
ET
KB
LM
LT
MS
PB
PI
PK
PP
PT
TA
TK
TL
TN
Survey
Sector
Figure 3.18.
Commonly encountered Invertebrate Taxa in each Survey Sector. See Figure
3.1 for Survey Sector locations.
Cephalopods
Holothurians
Seastars
Crustaceans
Gastropods
Crown of Thorns
0.5
0.45
0.4
Average Abundance
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
DK
ET
KB
LM
LT
MS
PB
PI
PK
PP
PT
TA
TK
TL
TN
Survey Sector
Figure 3.19.
Less frequently encountered Invertebrate Taxa in each Survey Sector. See
Figure 3.1 for Survey Sector locations.
48.
Results
3.6.2
Invertebrate Populations by Habitat Type
Figures 3.20 and 3.21 show respectively the abundance of commonly and less
frequently observed invertebrate taxa found associated with each of the fourteen
habitat types defined for the data set collected on Redang Island.
Urchins
Bivalves
Annelids
Crinoid Featherstars
Tunicates
Sea Cucumbers
1
0.9
Average Abundance
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Habitat Number
Figure 3.20
Mean abundance of commonly observed invertebrate families by Habitat
Type. Mean abundance refers to the values recorded on the 0-5 DAFOR
semi-quantitative abundance scale.
Holothurians
Cephalopods
Crustaceans
Seastars
Gastropods
Crown of Thorns
0.5
0.45
Average Abundance
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Habitat Number
Figure 3.21
Mean abundance of less frequently observed invertebrate families by Habitat
Type. Mean abundance refers to the values recorded on the 0-5 DAFOR
semi-quantitative abundance scale.
The abundance of Holothurians (Sea Cucumbers) across habitats three and eleven is
higher than that seen across all of the other habitats (0.83 and 0.99 respectively on the
semi-quantitative DAFOR scale). This is likely to relate largely to the feeding
mechanism of Holuthurians that sift through soft sediment, digesting organic matter
49.
Results
and organisms that inhabit the substrate. Both habitats three and eleven are
characterised as having sand and rubble as the dominant substrate.
Whilst the overall abundance of the more commonly encountered invertebrate taxa
found associated with habitats four and five is lower than across most of the other
habitats, it is worthy of note that the invertebrate taxa encountered show highly
equitable population structure with no one taxa dominating. This biodiverse situation
of seen in habitats four and five though is absent amongst all of the invertebrate
populations seen associated with the other habitat types.
The highest population of Crown of Thorns Starfish was observed in areas classified
as habitat five. Reference to the quantitative habitat descriptions reveals that this link
is likely to be as a result of the coralivorous nature of the Crown Of Thorns Starfish
and the abundant live hard coral cover associated with habitat five which provides an
abundant food source for the Starfish.
3.7
Management Value
Table 3.7 describes, through the use of five univariate reef health indicators, the
relative intrinsic biological values of the fourteen habitats defined from data collected
from the Redang archipelago. The two habitats with the greatest number of calculated
univariate means above the overall data set average are habitats four and five.
Referring back to the quantitative habitat descriptions, these two habitats are referred
to as frequently encountered mid to upper reef slope bedrock areas supporting diverse
live hard coral communities and upper reef slope areas with high live hard coral
cover dominated by Acropora and dead coral with algae. From these descriptions, it
is clear that both these habitats are shallow upper reef slope, areas of which around
Redang were found in many instances to have high benthic cover of living organisms.
Habitats with low overall conservation management value include habitats one, ten
and eleven. Habitat one is dominated by bare sand, with habitats ten and eleven being
dominated by both sand and rubble. With bare substrate being so dominant in all of
these areas, the coverage of live organisms is by definition lower and therefore the
ecosystem has less intrinsic biological value.
Habitat number two is interesting in that it has very low overall live hard coral cover.
Despite this, all remaining four variables are above the calculated global data set
average. This deeper water habitat supports particularly bio-diverse and varied coral
reef communities with no one life form of hard coral being dominant. Accordingly,
this creates many ecological niches and an ecosystem is consequently highly diverse.
50.
Results
BENTHIC
H'(loge)
COVHC
S
FISH
H'(loge)
Habitat
S
# VARIABLE > AVERAGE
1
2
52
114
2.41
4.10
0.11
1.42
30
63
2.85
3.22
0
4
3
4
5
108
148
116
4.06
4.26
4.03
1.66
2.85
3.56
59
105
68
3.25
3.26
3.16
4
5
5
6
7
66
85
3.73
3.83
2.80
2.41
42
41
3.12
2.78
3
3
8
9
10
12
76
48
2.20
3.48
3.50
2.50
0.97
1.29
19
43
25
2.74
3.19
2.83
1
1
0
11
12
73
63
3.45
3.67
1.36
1.13
41
30
2.95
3.08
0
2
13
14
76
56
3.80
3.67
2.00
2.36
41
42
3.19
3.13
3
3
Average
78.07
3.59
1.89
46.36
3.05
Table 3.7. Calculated values for five reef health indicators; three for benthic and sessile
organisms and two for fish assemblages, found associated with each habitat
defined. Average values across all habitats for each variable are shown. Values
in red exceed the calculated average value for that variable in that habitat.
Final column represents the number of reef health variables that are above
average for each habitat.
Using the spatial data on the distribution and composition of each survey transect
conducted, an overall average reef health has been calculated for each of the survey
transects completed. Using the spatial information collected with this data, it has been
possible to construct a map showing the management potential or each of these survey
transects with their geographic position. This map is shown as Figure 3.22.
51.
Results
Figure 3.22.
Calculated Management values for each survey transect completed during the Redang Island Phase of the MCRCP
52.
Results
Figure 3.22 shows the distribution of the relative conservation management values of
each transect and indicates that there is a heterogeneous distribution of coral reef and
ecosystem function around Redang Island. There is a cluster of transects all rated of
high management value around the northern area of Redang, in particular around
Teluk Dalam.
Using these values as a basis and the methodological principles discussed in section
3.8, the output Conservation Management Rating density grid is overlaid onto the
satellite image in Figure 3.23.
When interpreting the image, it is important to note that unclassified areas of reef do
not have low value, but instead have not yet been surveyed and therefore cannot be
included in the classification system.
Three areas are clearly identified in the image as being foci of high management value
and coral reef health. The first of these runs from Tajung Gua Kawah to Tanjung
Nyatoh on the east side of Teluk Dalam. The second, more spatially confined area
occurs on the deep reef walls around Tanjung Lang on the northwest corner of
Redang Island. Finally, the reefal areas around the Marine Park facility on Pulau
Pinang, especially around the northern most tip of the island and extending
southwards from Tanjung Baru Berak.
53.
Discussion
Figure 3.23
Conservation Management Rating image.
54.
Discussion
4
DISCUSSION
4.1
Training
The training programme used during the MCRCP Redang Island survey program has
proved to be appropriate for volunteer survey work in Malaysia. For example, the
results in the tests and in water validation exercise were excellent and, therefore, the
data collected during survey work are likely to be accurate and consistent. The
training schedule has been deemed appropriate for novice divers as well as relatively
experienced divers.
4.2
Oceanography and Anthropogenic Impact
The prevalent wind direction recorded during the period of the program at Redang
was from the South East and South. The data recorded and included in this report was
collected from March until September, the period of the year outside of the monsoon
which originates in the South China Sea and is accompanied by a prevailing wind
from the East. Strong winds during this period of the year are restricted to short
periods of climatic disturbance associated with the formation of small storm cells over
warm water bodies over the South China Sea. Indeed, the occurrence of strong winds,
whilst only occurring at less than ten of the observations made, originated from the
east over the South China sea.
Whilst wind speed and direction do not have a direct influence and impact on subtidal coral reef communities, they are the main driving influence behind both the
direction and magnitude of wind borne waves. The magnitude of waves is
proportional to the wind speed, though is also influenced by the distance over which
the wind blows across the sea surface; the fetch of the wave. A short fetch leads to the
formation of smaller, high frequency waves whilst a long fetch allows larger, oceanic
waves with a lower frequency to develop In turn the impact of these waves has direct
influence on the coral reef community both through direct impact on the organisms
themselves as well as controlling factors such as the dominant substrate types and
geomorphology at sites. As was seen in the Perhentian Islands, the shore line around
Redang is influenced by its aspect; north facing coastlines are steep and rugged and
the underwater topography is much higher than the more sheltered South facing
shorelines where lower wave energy during the monsoon period allows the deposition
of soft sediments.
The observations on water temperatures follow what is often observed in tropical
shallow water environments where vertical mixing of the water column is not strong.
The water body close to the surface where incoming solar irradiance is greatest is
subjected to warming at a rate faster than deeper water areas. This warmed water then
expands and becomes less dense, causing the formation of a stratification of the water
column with a surface layer of warmer, less dense water overlying a cooler body of
denser water. This stratification continues in the data set to a depth of about 22 meters
at which point the temperature decrease with depth stabilises at a temperature of
29.2o C.
The apparent patterns in observed under water visibility measured both vertically and
horizontally through the water column indicate the spatial variation in the quantity of
55.
Discussion
suspended sediments present in the water column. The data shows a general trend of
lowered water clarity or increased suspended solid content in the water column on the
west coast of the Island. Of fifteen survey sectors from which data is included in this
report, the four sectors with lowest visibility occur on this west coast. The remaning
sectors with lowered visibility as measured with the Secchi disc occurred offshore
from the sand substrate dominated areas around Pulau Kerengga (kecil and besar).
Sediment in the water column can come from two sources; from direct inundation in
coastal areas where rivers bring sediments of terrestrial origin into the marine
environment. The second source is from the re-suspension of sediments that had
previously been deposited onto the seabed. In the case of Pulau Redang the first
source is not likely to be significant as the Island are over 15 kilometers directly
offshore and are an even further distance from the nearest large river of Kuala
Terengganu. The main source of suspended solids observed around Redang is
therefore likely to be from the re-suspension via tidal mixing of sand on the seabed.
This is explains the location of where lowered underwater visibility was observed; all
of the areas are shallow, sand dominated areas that are prone to high current velocity.
The coral reefs around the Redang Islands are subject to a wide and varied degree of
anthropogenic impacts.
Boat activity is concentrated to two origins; those associated with the indigenous
population found on the village in Redang and also those associated with the tourism
industry. The two survey sectors with greatest boat activity were found around the
village on the south of the Island and around Pulau Kerangga Kecil and Besar. The
quantity of boats around the latter area are comprised largely of tourism boats
transporting guests between the resort developments and tourism facilities found on
the east coast of Redang Island. Some survey sectors had increased abundance of
boats that appeared to be engaged in fishing. Whilst this is obviously outlawed in the
Marine Park area under the 1985 Fisheries Act, evidence was observed in confined
regions that fishing was on-going. It is interesting to note that these regions where
fishing was observed are confined to the un-inhabited and more remote areas found
around the North West tip of Redang Island.
By far the most commonly observed surface impact between all survey sectors was
the occurrence of litter. In turn, this was largely concentrated around the village
population centre found in survey sector PT. At present, solid waste disposal facilities
in the village and to a lesser extent, in the wider developed coastal zone of Redang,
appear to be insufficient to deal with the solid waste generated on the Island.
Compared to data collected using the same methodology from the Perhentian Islands,
the frequency of occurrence of surface impacts around Redang is lower.
Again in terms of underwater impacts, the presence of litter was omnipresent in most
of the survey sectors. In addition, discarded gear was observed around the village area
and two fish pots were found whilst on surveys around Pulau Ekor Tebu. The main
danger with discarded fishing gear and in particular of no longer used fish traps is that
they can continue to ghost fish long after their commercial use has expired.
56.
Discussion
4.3
Benthic Data
In total fourteen habitats have been defined by multivariate analysis from the data set
collected around Redang Island. The multivariate methodology employed to identify
these habitats is a powerful one; it is likely that they are representative of all of the
different ha bitat types that can be found around the Island. Compared to similar
studies conducted by CCC in other Indo-Pacific regions; this number of habitat types
is typical of the genre of off-shore fringing reefs found around Redang Island.
The dominant feature of habitat differentiation seen was the effect of depth. The
habitats represented a range of depths from the extremely shallow and high exposure
reef crest to the low exposure and depositional environment lower reef slope.
As is typical throughout the Indo-Pacific ecoregion, the dominant shallow water coral
are the branching Acropora lifeforms. In selected areas of surveys around Redang
Island, the cover of branching Acropora corals exceeded 80%. With increasing depth,
this branching Acropora is replaced by additional life forms of both Acropora and
Non-Acropora. Indeed, one of the most biodiverse habitats was found around the
northern sections of Redang on the mid to lower reef slope and characteristically had
a biodiverse assemblage of live hard coral species and growth forms associated with
it.
4.4
Fish Data
Although it appears that fish populations in the Redang Islands are fairly low in their
abundance, there is a good representation of all of the major families. Particularly
abundant were the Rabbitfish (Siganidae) whilst Surgeonfish (Acanthuridae) were
absent. Parrotfish (Scaridae) were seen in high abundance in selected areas where they
were the dominant algal grazing component of the ecosystem.
The pairwise analysis of the interaction between fish assemblages in relationship to
the habitat types they were found associated with indicates that around the Redang
Islands, there is a close relationship between the two. Of particular note were the
similarities between fish assemblages found within the upper reef slope hard coral
dominated communities and the dissimilarity between these and the other habitats.
4.5
Invertebrate Data
Invertebrate populations throughout the Redang Islands have been shown to be
heterogeneous in their geographical distribution. This occurs because of two reasons;
firstly that invertebrate populations are closely linked with the habitat types of an
area, which in turn have their distribution, controlled by prevalent environmental
conditions. In addition, amongst many of the less frequently observed and mobile
invertebrates there is clear pattern in the data that indicates that populations are both
temporally and spatially distributed.
The feeding mechanisms of invertebrates are extremely widely varied and include
herbivores, omnivores and carnivores as well as filter, suspension and sediment
57.
Discussion
feeder. This has an affect on where populations of different groups of invertebrates
were observed. For example, the Holothurians main means of nutrition s through the
extraction of organic matter covering the surface of sand particles. Consequently,
Holothurians were most commonly observed in areas where sand formed the
dominant substrate, such as in the sheltered and enclosed bays on the west side of
Redang.
Holothurians support a commercially viable fishery in Malaysia where the main target
species is Stichopous horrens that is used in the manufacture of gamat oil. However,
Holothurians were the most commonly observed invertebrate taxa in this study. This
indicates that the fishing and extraction pressure on these species is, at present, low in
the Marine Park of the Perhentians. In addition, the large numbers of Tridacna spp.
clams, which are also commercially viable species, indicates that the invertebrate
population is well protected and/or unexploited in the Perhentians.
Crown of Thorns starfish (Acanathaster plancii) populations were found to be low
throughout all areas surveyed, with the maximum average observed population of less
than 0.2 per ten meter section of transect or 50meters squared (calculated using the
highest recorded abundance on the DAFOR scale across survey sectors of 0.15
recorded in sector MS). Crown of Thorn population outbreaks can be severely
damaging to hard coral cover on the reef where the invertebrate is a voracious
corallivores. Outbreaks are not uncommon in the Marine Park Islands of the East
coast of Peninsular Malaysia where outbreaks were recorded in Pulau Lima and Pulau
Ekor Tebu during the late 1970s (Rahman and Ibrahim, 1996). Indeed, during this
same period, the Redang Islands also suffered a population outbreak. The Marine
Parks Section considers normal population densities of COTs to be 6 per square
kilometre of reef (Rahman and Ibrahim, 1996). However, the observed densities in
this study equate to only two individuals per square kilometre of reef, well below the
threshold indicating the presence of any outbreak threat and encouraging for the
population control measures employed by the Marine Parks.
58.
Discussion
4.7
Management findings
The culmination of the analysis techniques employed in the report is the production of
the conservation management value contour image (Fig 3.23). A few things should be
considered about the image however. Firstly, areas that have not been classified have
not been surveyed to date. In addition, the one survey conducted on Lang Tengah is
insufficient to make reliable estimates of the conservation value of this region.
Accordingly, this area has not been included in the contour image. The image is
produced by an inverse weighted algorithm where by the calculated conservation
management value of each transect is used to extrapolate to fill the value of the unsurveyed areas between. If the coral reef areas are arranged in a linear manner, this is
a highly accurate technique. However, around the irregularly shaped Redang Island,
the extra dimension means that extrapolations are made into deeper water and do not
truly represent the spatial distribution of the reefs. Finally, the conservation
management rating scheme is comparative only to the data used to devise the
classification. A high, medium or low value area identified around Redang could not
be directly compared for example to another area around another island chain.
Nevertheless, and despite these limitations of the technique, if the image is considered
at the whole-island scale for which it was intended, it does provide an extremely
useful tool for the identification of areas with high intrinsic biological value.
The three areas that have been identified as of high intrinsic biological value support
some of the most biodiverse coral reef communities found around Redang Island.
Overall, although there is a range of both natural and anthropogenic disturbances that
act on the reefs around Redang Island, the data assimilated in this report appears to
indicate that these resources are being well managed. Many of the impacts affect
spatially discreet areas such as those around the village population centre. It is
interesting to note that of the three areas of high value, two are located on the northern
and less developed side of the Island. It is a recommendation therefore that
development within these regions be tightly controlled to minimise impact on the high
value coral reef systems found in the locality.
One extremely positive sign of the regulation of recreational use impact is identified
around the Marine Park Center Island, Pulau Pinang. Despite being the site of greatest
recreational use intensity in the Redang Islands, the coral reef area around this facility
has been identified as being a focus of high biodiversity and ecosystem function. This
appears to indicate that whilst some impact of such high intensity use is inevitable,
management initiative employed by the Marine Park system prevent major negative
impacts from occurring.
The intention at present to enter a collaboration with the Malaysian Centre of Remote
Sensing to allow the undertaking of a comprehensive mapping exercise of the coral
reef resources of Redang will allow the data collected and presented in this report to
be used to produce a detailed Geographic Information System on the area. This GIS
will include a habitat map outlining the geographic areas over which each of the
habitat types is encountered. In addition, using the baseline field collected data, it is
possible to produce images outlining many facets of the natural resources to include,
for example, the cover of live hard coral.
59.
Discussion
Such a comprehensive GIS can be used to form the basis of a decision making system
whereby areas of reef can be used into a multi-use zoning scheme to ensure the
protection of naturally sensitive and important habitat areas from, for example,
development pressure.
60.
References
REFERENCES
Aikanathan, S. and Wong, E.F.H. 1994. Marine park management conceptual plan for
Peninsula Malaysia. Department of Fisheries Malaysia and WWF-Malaysia.
Aronson, R.B.and Precht, W.F. 1995. Landscape patterns of reef coral diversity: A
test of the intermediate disturbance hypothesis. Journal of Experimental Marine
Biology and Ecology. 192 Issue1. 1-14
Bray, J.R., and J.T. Curtis. 1957. An ordination of the upland forest communities of
Southern Wisconsin. Ecological Monographs 27: 325-349.
Chou, L.M. and 9 other authors. Status of coral reefs in the ASEAN region. Pages: 110. In: Wilkinson, C.R., Suraphol Sudara and Chou, L.M (Eds). Proceedings of the
Third ASEAN-Australia Symposium on Living Coastal Resources. Volume 1: Status
reviews. Australian Institute of Marine Science.
Christ, C., Hillel, O., Matus, S. and Sweeting, J.2003 Tourism and Biodiversity:
Mapping Tourism’s Global Footprint. Conservation International and United Nations
Environment Program. Available online at
http://www.unep.org/PDF/Tourism_and_biodiversity_report.pdf
Clarke, K.R. 1993. Non-parametric multivariate analyses of changes in community
structure. Australian Journal of Ecology 18: 117-143.
Clarke K.R. and Warwick R.M (1994). Change in Marine Communities: An Approach
to Statistical Analysis and Interpretation. 1st edition: Plymouth Marine Laboratory,
Plymouth, UK, 144pp.
Comley J., Harding, S., Raines, P. Helgeveld, M. and Coltman, N. 2003. Baseline data
collection to facilitate sustainable marine resource use in the Pulau Perhentian
Archipelago, Terrenggannu. Poster presentation at the Seminar on Islands and Reefs:
Towards Conservation and Sustainable Management, Kuala Lumpur, August 2003.
Darwall, W.R.T. and N.K. Dulvy. 1996. An evaluation of the suitability of nonspecialist volunteer researchers for coral reef fish surveys. Mafia Island, Tanzania – A
case study. Biological Conservation 78: 223-231.
English, S., C.R. Wilkinson and V. Baker (Eds). 1997. Survey manual for tropical
marine resources. Australian Institute of Marine Science. 2nd edition.
Erdmann, M.V., A. Mehta, H. Newman and Sukarno. 1997. Operational Wallacea:
Low-cost reef assessment using volunteer divers. Proceedings of the 8th International
Coral Reef Symposium 2: 1515-1520.
Faith, D.P., Minchin, P.R., and L. Belbin. 1987. Compositional dissimilarity as a
robust measure of ecological distance. Vegetatio 69: 57-68.
61.
References
Harborne, A., Fenner, D., Barnes, A., Beger, M., Harding, S., Roxburgh, T. 2000.
Status report on the coral reefs of the East coast of Peninsular Malaysia. In Press (2nd
printing).
Harborne, A.R., D.C. Afzal, M.J. Andrews and J.M. Ridley. 2003. Beyond data: The
expanded role of a volunteer programme assisting resource assessment and
management in the Bay Islands, Honduras. Proceedings of the 9th International Coral
Reef Symposium.
Harding, S, Lowery, C and Oakley, S. 2003. Comparison between complex and
simple reef survey techniques using volunteers: is the effort justified? Proceedings of
the 9th International Coral Reef Symposium, Bali.
Hendry, H.J. 2000. Update on the status of the coral reef ecosystems and management
of the Pulau Tioman Marine Park, Peninsular Malaysia. Unpublished report to WWFMalaysia.
Hunter, C. and J. Maragos. 1992. Methodology for involving recreational divers in
long-term monitoring of coral reefs. Pacific Science 46: 381-382.
Lorah, P. 1996. An Unsustainable Path: Tourism's Vulnerability to Environmental
Decline in Antigua. Caribbean Geography.29 76-82
Marshall, P.A. and A.H. Baird. 2000. Bleaching of corals on the Great Barrier Reef:
differential susceptibilities among taxa. Coral Reefs 19: 155-163.
Mumby, P.J. and A.R. Harborne. 1999. Development of a systematic classification
scheme of marine habitats to facilitate regional management and mapping of Caribbean
coral reefs. Biological Conservation 8: 155-163.
Mumby, P.J., A.R. Harborne, P.S. Raines and J.M. Ridley. 1995. A critical
assessment of data derived from Coral Cay Conservation volunteers. Bulletin of
Marine Science 56: 737-751.
Rahman, R.A., Ibrahim, S.N.S., 1996. Pulau Redang Marine Park Malaysia.The
National Advisory Council for Marine Parks and Marine Reserves; The Department
of Fisheries Malaysia.
Ridzwan, A.R. 1994. Status of coral reefs in Malaysia. Pages: 49-56. In: Wilkinson,
C.R., Suraphol Sudara and Chou, L.M (Eds). Proceedings of the Third ASEANAustralia Symposium on Living Coastal Resources. Volume 1: Status reviews.
Australian Institute of Marine Science.
Veron, J.E.N. 2000. Corals of the World. 3 Vols. M. Stafford-Smith (Ed.). Australian
Institute of Marine Science Monograph Series.
Wells, S.M. 1995. Reef assessment and monitoring using volunteers and nonprofessionals. University of Miami.
62.
Appendices
APPENDIX I
CCC BASELINE SURVEY RECORDING FORMS
63.
Appendices
64.
Appendices
65.
Appendices
66.

MALAYSIA CORAL REEF CONSERVATION PROJECT: PULAU

Transcription

Similar documents

Terumbu Karang dan Perubahan Iklim Coral Reefs

48x96 poster template

Detailed PDF file available click here!

Estimating the Conservation Value in Redang Island Marine Park: A

Southern Leyte Coral Reef Conservation Project (SLCRCP)

What`s coral reef

Hawai`i Wildlife Watching Guide

Mutton Fish Point

2nd Floor • Aquarium Adventure Exhibit 1st Floor • Aquarium

Reef Check Malaysia