ArticlePDF Available

Seagrass diversity and distribution in the Koh Rong Archipelago, Preah Sihanouk Province, Cambodia

Authors:

Abstract and Figures

Seagrass habitats around Cambodia's off shore islands have been litt le studied and are under threat from various anthropogenic factors, especially those related to destructive fi shing techniques. Field surveys were conducted in 2013 and 2014 during the dry season around both islands within Cambodia's fi rst proposed Marine Fisheries Management Area: Koh Rong and Koh Rong Sanloem. The surveys aimed to evaluate seagrass distribution, abundance and diversity around the islands, and employed transect and quadrat methods to sample seagrass species richness and percentage cover. The area was found to contain an estimated 18 hectares of seagrass habitat. Four species of seagrass were recorded: Halodule pinifolia, Thalassia hemprichii, Enhalus acoroides and Halophila minor. The commonest species was Halodule pinifolia. The highest percentage cover of seagrass was found in areas where the benthos was course sand. This study represents the fi rst comprehensive assessment of seagrass species composition in the Koh Rong Archipelago and provides a baseline for future monitoring.
Content may be subject to copyright.
37
© Centre for Biodiversity Conservation, Phnom PenhCambodian Journal of Natural History 2014 (1) 37–46
Seagrasses in the Koh Rong Archipelago
Seagrass diversity and distribution in the Koh Rong Archipelago,
Preah Sihanouk Province, Cambodia
LENG Phalla1,*, Sophie BENBOW2 and Berry MULLIGAN1
1 Fauna & Flora International, Cambodia Programme,19, Street 360, BKK1, Khan Chamkarmorn, PO Box 1380,
Phnom Penh, Cambodia.
2 Fauna & Flora International, Jupiter House, 4th Floor, Station Road, Cambridge, CB1 2JD, UK.
*Corresponding author. Email lengphalla.f @gmail.com
Paper submitted 3 May 2014, revised manuscript accepted 18 July 2014.
CITATION: Leng P., Benbow, S.L.P. & Mulligan, B. (2014) Seagrass diversity and distribution in the Koh Rong Archipelago,
Preah Sihanouk Province, Cambodia. Cambodian Journal of Natural History, 2014, 37–46.
Abstract
Seagrass habitats around Cambodia’s o shore islands have been li le studied and are under threat from various
anthropogenic factors, especially those related to destructive shing techniques. Field surveys were conducted
in 2013 and 2014 during the dry season around both islands within Cambodia’s rst proposed Marine Fisheries
Management Area: Koh Rong and Koh Rong Sanloem. The surveys aimed to evaluate seagrass distribution,
abundance and diversity around the islands, and employed transect and quadrat methods to sample seagrass
species richness and percentage cover. The area was found to contain an estimated 18 hectares of seagrass habitat.
Four species of seagrass were recorded: Halodule pinifolia, Thalassia hemprichii, Enhalus acoroides and Halophila
minor. The commonest species was Halodule pinifolia. The highest percentage cover of seagrass was found in areas
where the benthos was course sand. This study represents the rst comprehensive assessment of seagrass species
composition in the Koh Rong Archipelago and provides a baseline for future monitoring.
Keywords
Fisheries, Marine Fisheries Management Area, MPA, percentage cover.
38
© Centre for Biodiversity Conservation, Phnom Penh Cambodian Journal of Natural History 2014 (1) 37–46
Leng P. et al.
Introduction
Seagrasses are aquatic owering plants located
mainly in shallow, sheltered nearshore areas (Carlo
& McKenzie, 2011), and are usually found between
mangroves and coral reefs in tropical areas (Short
et al., 2001, in UNEP, 2008). They are an important
food for many species including dugongs Dugong
dugong and green turtles Chelonia mydas (Serey-
wath & Sokhannaro, 2003; Smyth, 2006). Seagrasses
also provide essential nursery habitat and breeding
grounds for some important shes (Unsworth et al.,
2006) and invertebrates, and play a role in protecting
fringing coral reefs from the impacts of sedimenta-
tion (Short et al., 2001, in UNEP, 2008). Seagrass beds
provide shing areas for shermen (Cullen-Unsworth
et al., 2013), but the species associated with them
are particularly vulnerable to over shing because
such sheltered areas can be targeted even when bad
weather restricts access to o shore shing sites. If
seagrass areas become degraded, sh stocks could
decline because many sh species utilise seagrass
as nursery habitat prior to migrating to coral reefs
(Nagelkerken et al., 1999).
Cambodia’s coastline stretches 440 km along the
Gulf of Thailand. Kep Province borders Vietnam to
the East, and Koh Kong Province borders Thailand to
the West. Cambodia’s coastal zone is comprised of the
world’s largest seagrass areas (Johnson & Munford,
2012). A national report on seagrass in the South
China Sea (UNEP, 2008) indicated that seagrasses
were found in shallow water throughout most of the
country’s coastal zone. Seagrass beds in Cambodia
cover 33,814 hectares, but relatively li le of this area is
currently under e ective management by the Fisheries
Administration (Table 1).
Seagrass habitats in Cambodia can be found in
two forms: either in extensive meadows adjacent to
the mainland, or in patches of seagrass inter-mixed
with corals around islands (Ethirmannasingam,1996
in Nelson, 1999). Kampot Province is the largest
seagrass area, but smaller beds are also found around
Koh Kong, Kep and Preah Sihanouk provinces (MFF,
2013), including areas bordering the o shore islands
of Koh Rong Sanloem and Koh Rong (Ethirman-
nasingam,1996 in Nelson, 1999). However, there is a
lack of information about the environmental factors
in uencing seagrass distribution and abundance in
Cambodia (UNEP, 2008).
Approximately 60 species of seagrass have been
observed globally (Short et al., 2007) of which 18
species have been recorded in Southeast Asia (Anony-
mous, 2014). Previous studies in Cambodia’s Kampot
Province have reported 12 species (Ouk et al., 2010).
Seagrass areas in Cambodia are threatened by
destructive shing practices, including trawling for
shrimp (Adulyanukosol, 2002) and push-ne ing (Tana,
1995 in UNEP, 2008). In addition, water quality has
declined in recent years due to high levels of nutrient
input from terrestrial run-o following agricul-
tural use of fertilizers and pesticides and increasing
sedimentation following erosion from unsustainable
logging practices (UNEP, 2008). Nutrient input and
sedimentation increase water turbidity and inhibit
seagrass growth by reducing light, which a ects the
ability of seagrass to photosynthesise (Duarte et al.,
1997; Hemmings & Duarte, 2000; UNEP, 2008).
Cambodia’s rst Marine Fisheries Management
Area (MFMA) is currently being established around
the islands of Koh Rong and Koh Rong Sanloem by the
Government of Cambodia’s Fisheries Administration
(FiA), with support from Fauna & Flora International
(FFI) and several other partners and stakeholders.
Environmental a ributes favouring the selection
of this area for an MFMA include its diversity of
habitats, such as mangroves, coral reefs and seagrass
areas as well as records of endangered marine species.
For example, these areas are known to be inhabited by
sea turtles (Leng P., pers. obs; FFI, 2013) and seahorses
(MCC, 2011a). However, the species distribution,
abundance and composition of seagrass beds in Koh
Rong and Koh Rong Sanloem are largely unknown.
These data are required to inform the design of a
zoning scheme for the MFMA.
After obtaining permission from FiA in April 2013
(le er 2948), eld surveys were conducted to evaluate
seagrass distribution, abundance and diversity
during both the 2013 and 2014 dry seasons. Surveys
were conducted collaboratively with and by local
stakeholders, including the Department of Fisheries,
FFI, local authorities from Koh Rong and Koh Rong
Sanloem and Community Fisheries (CFi) members
from four villages.
Methods
Study site
This study was conducted around Koh Rong and Koh
Rong Sanloem in Preah Sihanouk Province. These
islands lie within the proposed MFMA. Four villages
were selected for this study: three villages on Koh
39
© Centre for Biodiversity Conservation, Phnom PenhCambodian Journal of Natural History 2014 (1) 37–46
Seagrasses in the Koh Rong Archipelago
Rong (Koh Touch, Daem Thkov and Prek Svay) and
one village on Koh Rong Sanloem (Koh Rong Sanloem
village, also known as M’Pai Bai) (Fig. 1), all of which
lie within CFi areas and receive support from local
and international NGOs. Small-scale shing takes
place in these seagrass areas.
Field Methods
Surveys were conducted by sta from FiA and FFI as
well as representatives from the Community Fisheries
Commi ee and local villages. For the rst eld season
(2013), seagrass sites were selected through exami-
nation of existing habitat maps produced by other
organisations and researchers working in the area
(Skopal-Papin, 2011) and national natural resources
maps (e.g. SCW, 2006), as well as consultation with
the community sheries and villagers. For the second
eld season in 2014, we revisited the sites that had
been surveyed in 2013.
The rst surveys were completed between April
and May 2013 by snorkelling. During this survey, six
sites were sampled and a total of 30 transects were
conducted across these sites (Fig. 2). Prior to the
transects being laid, the eld observers snorkelled
around the sites to identify areas with the highest
seagrass coverage, and transects were located on these
areas. The second survey was completed in March
2014 using snorkelling and SCUBA. In this survey,
nine sites were sampled and a total of 45 transects
were completed. Where possible, the 2014 transects
were placed in the same locations as the 2013 transects
by using their GPS coordinates. The survey method
was adapted from Ouk et al. (2010), whereby 10-m
transects were laid perpendicular to the shoreline, and
50 cm x 50 cm quadrats were laid along each transect
at 5-m intervals. These quadrats were divided into 25
sectors, each measuring 10 cm x 10 cm, to increase ease
of sampling and reduce error in visual cover estimates
(English et al., 1997). For each quadrat, all species
present were identi ed in situ using a laminated
seagrass identi cation sheet for reference (Short et al.,
2001). The percentage cover of each species, and total
seagrass coverage for each quadrat, were estimated
using a seagrass percentage cover guide sheet (Ouk et
al., 2010).
In addition to these measurements, a dive
computer was used to record water depth during the
2014 surveys, and a metric rule was used to measure
the height of the seagrass.
Results
Four species of seagrass were recorded during this
study around Koh Rong and Koh Rong Sanloem;
Halodule pinifolia, Enhalus acoroides, Halophila minor
and Thalassia hemprichii. Mean seagrass percentage
cover was higher in the Deam Thkov sites than Koh
Touch, Koh Rong Sanloem and Prek Svay (Fig. 3).
The Daem Thkov sites were dominated by Halodule
pinifolia, whereas T. hemprichii was the commonest
species observed around both Koh Rong Sanloem
and Koh Touch. All four species of seagrass were
recorded near Daem Thkov village, whereas only H.
pinifolia and T. hemprichii were documented at Koh
Touch and only one species was recorded at both Koh
Rong Sanloem (T. hemprichii) and Prek Svay (Halodule
pinifolia) (Fig. 3). The percentage cover of Enhalus
acoroides and Halophila minor was low, but both species
were observed fairly regularly throughout the sites.
Seagrass surveys were conducted at water depths of
between 0.4 and 1.9 m, and there was considerable
Table 1 Overview of seagrass extent in Cambodia and
current state of management (MFF, 2013). *In a conserva-
tion site managed by FiA or CFi.
Province
Known
seagrass
extent
Seagrass
area under
management*
Percentage
under
management
Kep 3,905 ha 731 ha 19%
Kampot 25,240 ha 1,500 ha 6%
Koh Kong 3,993 ha 1,000 ha 25%
Preah
Sihanouk 1,468 ha 600 ha 41%
Table 2 Seagrass species with their range of water depths
and foliage dimensions.
Species Water
depth (m)
Species foliage
dimensions
Enhalus acoroides 0.5–0.7 Length 12–46 cm
Width 1.5–1.5 cm
Halodule pinifolia 0.4–1.5 Length 4–12 cm
Width 0.25–0.7 cm
Thalassia hemprichii 0.4–1.9 Length 0.9–1.4 cm
Width 0.7–1.0 cm
Halophila minor 0.4–1.5 Length 0.3–1.0 cm
Width 0.4–0.7 cm
40
© Centre for Biodiversity Conservation, Phnom Penh Cambodian Journal of Natural History 2014 (1) 37–46
Leng P. et al.
variation in the range of foliage dimensions within
and between species (Table 2). Based on the 2013
survey, we estimate the total area of seagrass in the
Koh Rong Archipelago to be 18 hectares.
Site speci c results
Koh Rong Sanloem
The seagrass bed by Koh Rong Sanloem is located
seaward of an area of fringing mangrove. Inter-annual
variation in overall seagrass percentage cover between
the two surveys on Koh Rong Sanloem was low (44%
in 2013 and 41% in 2014). However, in 2013 only one
seagrass species was recorded, whereas in 2014 both
T. hemprichii and Halodule pinifolia were observed
(although H. pinifolia was not recorded within the
sampling quadrats). We inferred that H. pinifolia was
present in low abundance, possibly representing
a 5% share of coverage overall, while T. hemprichii
was dominant. The substrate was sand, with some
seaweed and bivalves (bicolour pen shell Pinna bicolor
and common geloina Polymesoda [Geloina] erosa).
Other species recorded during the surveys included
sea stars, collector sea urchins, several schools of small
sh, and one unidenti ed species of seahorse. The
seagrass bed covered approximately 150 m x 150 m.
Fig. 1 Map of the study site
showing villages and estimated
extent of seagrass beds.
41
© Centre for Biodiversity Conservation, Phnom PenhCambodian Journal of Natural History 2014 (1) 37–46
Seagrasses in the Koh Rong Archipelago
Daem Thkov
Similar to Koh Rong Sanloem, the seagrass areas of
Daem Thkov were directly adjacent to mangroves.
Daem Thkov was the most species-rich site, with four
species of seagrass recorded in 2013. However, we
observed a decrease in the number of species between
the two eld seasons, as T. hemprichii was not recorded
in 2014 (Fig. 4). This site was dominated by H. pinifolia
(73%) and relatively small numbers of the other three
species in 2013 (Halophila minor 9%, T. hemprichii 3.33%
and Enhalus acoroides 6%). The benthos was composed
of course sand, and many invertebrate species were
sighted, including sea stars, crabs, octopuses, collector
sea urchins and bivalves (e.g. bicolour pen shell and
mud creeper Terebralia sp.) as well as small schools of
sh. Seahorses were not sighted in 2013, but during the
2014 surveys we recorded 14 individuals representing
three di erent species. The seagrasses of Daem Thkov
covered around 10 ha, but the area of high seagrass
species diversity was limited to 2 ha (Fig. 1).
Prek Svay
In 2013, no seagrasses were recorded around Prek
Svay, but after consulting local shers in 2014, an
Fig. 2 Approximate survey
locations in 2013 and 2014.
42
© Centre for Biodiversity Conservation, Phnom Penh Cambodian Journal of Natural History 2014 (1) 37–46
Leng P. et al.
Table 3 Description of all seagrass survey sites.
Year Site Local Site
Name
Nearest
village
Species
richness
Dominant
species? Substrate Geophysical description
2013
1 Av Lich Daem Thkov 3 Halodule pinifolia Coarse sand
and sand
In front of the mangrove
2 Av Lich Daem Thkov 3 Halodule pinifolia Coarse sand
and sand
In front of the mangrove
3 Av Lich Daem Thkov 3 Halodule pinifolia Coarse sand
and sand
In front of the mangrove
4 Av Lich Daem Thkov 4 Halodule pinifolia Coarse sand
and sand
In front of the mangrove
1 Av Yiy Koh Rong
Sanloem
1Thalassia hemprichii Sand In front of the mangrove
2 Av Yiy Koh Rong
Sanloem
1 No Sand In front of the mangrove
1 In front of
village
Koh Touch 2 Thalassia hemprichii Sand In front of the forest
2014
1 Av Lich Daem Thkov 2 Halodule pinifolia Coarse sand In front of the mangrove
2 Av Lich Daem Thkov 2 Halodule pinifolia Coarse sand In front of the mangrove
3 Av Lich Daem Thkov 1 Halodule pinifolia Coarse sand In front of the mangrove
4 Av Lich Daem Thkov 1 Halodule pinifolia Coarse sand In front of the mangrove
5 Av Lich Daem Thkov 1 Halodule pinifolia Coarse sand In front of the mangrove
6 Av Lich Daem Thkov 2 Halodule pinifolia Coarse sand
and sand
In front of the mangrove
1 Av Yiy Koh Rong
Sanloem
2Thalassia hemprichii Sand In front of the mangrove
2 Av Yiy Koh Rong
Sanloem
2 No Sand In front of the mangrove
1 Av Thean
Koh Dong
Prek Svay 2 No Sand In front of the mangrove
1 In front of
village
Koh Touch 2 Thalassia hemprichii Sand In front of the forest
area of seagrass was observed at Av Thean in front
of fringing mangrove. Two species of seagrass were
recorded here: Halodule pinifolia (3.5%) and Halophila
minor, although H. minor was not recorded within the
survey quadrats. The substrate was mainly sand and
ne sand, and some species, such as anemone sh,
collector sea urchins, sea stars and schools of small
sh, were observed. The total area of the seagrass bed
covered 100 m x 100 m and included small patches on
the boundary with small seagrass shoots that we were
unable to identify to species level.
Koh Touch
The extent of seagrass at Koh Touch was small, covering
an area of only 20 m x 20 m, so observations were
made by snorkelling. No transects were conducted
here because the seagrass bed was too small. Overall
species coverage decreased between the 2013 and
2014 surveys: Thalassia hemprichii coverage decreased
from 85% to 25% and Halodule pinifolia decreased
from 15% to 5%. The substrate of this site was sand
with seaweed and some invertebrate species, such as
collector sea urchins and bivalves (bicolour pen shell,
common geloina), and groups of small sh.
43
© Centre for Biodiversity Conservation, Phnom PenhCambodian Journal of Natural History 2014 (1) 37–46
Seagrasses in the Koh Rong Archipelago
Discussion
Four species of seagrass were recorded across the
survey sites over the study period. Our data appear
to show that percentage cover of the seagrass species
varied both between sites and between years. Halodule
pinifolia was the commonest species in all sites, and
Daem Thkov Village had the highest percentage cover
of seagrass overall and seemed to present the most
suitable environment for seagrass growth. The loss
of some species seen between the two years of the
eld surveys is problematic and may be the result of
increasing human impacts on the area or sampling
error. Increased shing e ort in seagrass areas,
particularly using techniques which physically impact
on the seabed, may be reducing seagrass coverage
(as reported by shermen in Daem Thkov and Koh
Rong Sanloem during the 2014 seagrass survey).
We note that the seagrass area of Daem Thkov is a
popular shing site (Daem Thkov CFi chief Mr Ban,
pers. comm.), particularly using crab gill-nets, which
supports our theory that shing activities may be
negatively a ecting seagrass.
Fig. 3 Mean overall percentage cover of seagrass species
per quadrat (2013 and 2014 data combined).
Fig. 4 Seagrass cover by species near Daem Thkov Village.
44
© Centre for Biodiversity Conservation, Phnom Penh Cambodian Journal of Natural History 2014 (1) 37–46
Leng P. et al.
According to our observations, the patch of
seagrass at Koh Touch was small and decreased in size.
The perceptions of the local village chief in 2014 also
support the idea that the seagrass area is shrinking,
reportedly as a result of damage by strong winds and
waves. Koh Touch is also rapidly becoming a popular
tourist site, and during the peak season more than 100
tourists per day may pass through the area (Koh Rong
Sanloem CFi, unpublished data), hiring local boats
for sea cruises that anchor in seagrass areas and cause
further damage. No data are available from this busy
village to determine whether changes in water quality
may have a ected the nearby seagrass bed.
Koh Rong Sanloem is a good place for seagrass,
but it is a popular shing site. We propose that the
MFMA zoning plan allows measures to reduce shing
impacts on this ecologically important area. During
this study, we observed T. hemprichii and H. pinifolia
by Koh Rong Sanloem. Earlier observations by MCC
(2011b) found a further two species—Cymodocea serru-
lata and Halophila ovalis—in the Koh Rong Sanloem
CFi that were not observed during our study. Their
precise locations were unclear from the report,
however, so there might not necessarily have been a
real change in species composition.
Seagrasses provide an important marine habitat
for a number of species and form an important part
of the coastal ecosystem linking mangroves to coral
reefs (Unsworth et al., 2006). Seagrass areas in the
Koh Rong Archipelago were predominantly associ-
ated with fringing mangroves, of which there are 128
hectares in the archipelago (FFI, unpublished data).
Large numbers of invertebrate species recorded at
several sites around Koh Rong Sanloem and Daem
Thkov Village provide further evidence of the impor-
tance of seagrass beds for a number of species. Three
species of seahorses were observed near Daem Thkov
Village and at least one, identi ed as Hippocampus
spinosissimus, is listed as Vulnerable on the IUCN
Red List (Wiswedel, 2012). In addition, octopuses and
crabs were observed in seagrass sites—both commer-
cially important taxa for local shers. Interviews with
shers suggest the crab shery has declined in this
area (Leng, 2013) and underline the importance of
protecting the remaining intact habitats.
There is evidence of general decline in the extent
of seagrass coverage over time in the Koh Rong Archi-
pelago. Previous surveys recorded seven seagrass
areas around Koh Rong (Skopal-Papin, 2011), but our
study identi ed only three sites suitable for surveys.
Similarly, three suitable survey sites were previously
identi ed around Koh Rong Sanloem (Skopal-Papin,
2011), but our study located only one. Anecdotal
reports suggest that one area northeast of Koh Rong
Sanloem used to have a small seagrass bed (included
on maps in Skopal-Papin, 2011), but that area was
impacted by spillage and pollution from a nearby fuel
trading depot, and the seagrass has gone. Conversely,
the current study suggests the sites surveyed around
Daem Thkov support the largest and most species-rich
area of seagrass, the extent of which is greater than
that reported by Skopal-Papin (2011). In addition,
seagrass sites around Prek Svay identi ed by Skopal-
Papin (2011) were not located, although re-growth was
evident at a small, previously unrecorded seagrass
bed north of Koh Rong, near Koh Dong.
Human impacts appear to be widespread in
the remaining seagrass habitats in the archipelago,
including e ects from shing and, potentially,
land-based pollution in some sites. Trawling and
push-ne ing are the most damaging shing activi-
ties for the seagrass beds in Cambodia (UNEP, 2008).
Speci c examples have been gathered through local
interviews of trawlers damaging seagrass beds histor-
ically (e.g., near Koh Touch), as well as the perception
that illegal fast trawls are a signi cant threat to local
livelihoods and marine resources (Leng, 2013).
It is important to note that our analysis did not
include all seagrass beds in the archipelago. National
natural resources maps (SCW, 2006) estimate there are
as many as 92 hectares of seagrass in the study site,
and Skopal-Papin (2011) reported approximately 47
hectares in the Koh Rong Archipelago: considerably
more than the 18 hectares estimated from this study
using 2013 data. It is important to recognise these
gures do not necessarily indicate the actual rate
of seagrass decline due to the di culties in directly
comparing data produced using di erent methods
across di ering spatial scales, and the limited histor-
ical data sources. During our study, some areas were
reported but not veri ed during the rst site visits in
2013; for example, an area of seagrass to the east of
Koh Rong (Barnaby Olsen, pers. comm.). In contrast
to the intensive eld work undertaken here, the
available historical extent estimates from SCW used
coarse-resolution spatial data for the entire Cambo-
dian coast. Seasonal variations in extent are also
possible (Govindasamy et al., 2013), and the timings
of previous surveys of seagrass are unknown. While
providing the most detailed information available to
date, the seagrass distribution maps in Skopal-Papin
(2011) were not based on comprehensive archipelago-
wide surveys targeting seagrasses, and included rough
estimates of seagrass extent based on visual observa-
tions by divers (M. Skopal-Papin, pers. comm.).
45
© Centre for Biodiversity Conservation, Phnom PenhCambodian Journal of Natural History 2014 (1) 37–46
Seagrasses in the Koh Rong Archipelago
Despite such uncertainties among these various
data sets, an overall downward trend of seagrass
habitats is supported by anecdotal reports from local
people concerning human impacts on the seagrass
beds and declines in their extent. The present study
provides a more comprehensive baseline against
which future trends, and the e ectiveness of manage-
ment activities, can be measured. This study also
highlights the challenges in tracking the various
national area-based targets for marine habitats. For
example, within the Strategic Planning Framework for
Fisheries, the government aims to secure at least 7,000
ha of seagrass under an appropriate form of sustain-
able management by the end of 2019 (FiA, 2011).
Conclusions
Seagrasses provide important habitats for commer-
cially valuable sh and invertebrate species. Our
study has found evidence of some declines in seagrass
coverage and species richness in the Koh Rong Archi-
pelago. This highlights the need for including seagrass
beds—in particular those around the village of Daem
Thkov—into conservation zones during the MFMA
zoning consultation, to ensure the long-term sustain-
ability of the MFMA and to meet national level targets
for marine habitat protection. Recent e orts by the
CFi in Daem Thkov to reduce shing pressure within
seagrass habitats suggest that CFi members can play a
key role in preserving this crucial marine habitat.
Acknowledgements
Thanks to Ouk Vibol and two anonymous reviewers
for providing advice and edits on this paper, and to
Nhem Vanna, Mom Sokdara, Hout Vuthy for their role
in data collection, as well as Kylie Gavard (Conserva-
tion Cambodia) and Rónán Mag Aoidh (Coral Cay
Conservation) who assisted in the 2014 surveys.
Choun Phirom and Sim Sovannrun helped to generate
the seagrass maps. Additionally, we thank the village
chiefs, Community Fishery Commi ees, and other
local people who cooperated in these surveys and
showed us where to nd seagrass. We would also
like to thank the Ministry of Agriculture, Forestry and
Fisheries, Department of Fisheries Conservation and
Fishery Cantonment at Preah Sihanouk Province for
their support and cooperation in the eld surveys.
The U.S. Fish & Wildlife Service, the UK government’s
Darwin Initiative and Prince Albert II of Monaco
Foundation generously provided funds to support
this research to inform the design of the proposed
MFMA in the Koh Rong Archipelago.
References
Adulyanukosol, K. (2002) Report of Dugong and Seagrass
Survey in Vietnam and Cambodia. Phuket Marine Biological
Center, Phuket, Thailand.
Anonymous (2014) Seagrasses: the Least Understood of the
Coastal Canaries. Biodiversity Information Sharing Service
(ASEAN Clearing House mechanism). H p://chm.asean-
biodiversity.org/index.php?option=com_content&view=a
rticle&id=169&Itemid=169 [accessed 1 May 2014].
Carlo, G. D. & McKenzie, L. (2011) Seagrass Syllabus: a
Training Manual for Resource Managers. Conservation Inter-
national, Arlington, USA.
Cullen-Unsworth. L.C., Nordlund. L.M., Paddock. J., Baker.
S., McKenzie, L.J. & Unsworth, R.K.F. (2014) Seagrass
meadows globally as a coupled social-ecological system:
implication for human wellbeing. Marine Pollution Bulletin,
83, 387–397.
Duarte, C., Terrados, J., Agawin, N.S.R., Fortes, M.D., Bach,
S. & Kenworthy, W.J. (1997) Response of a mixed Philip-
pine seagrass meadow to experimental burial. Marine
Ecology Progress Series, 147, 285–294.
English, S., Wilkinson, C. & Baker, V. (eds) (1997) Survey
Manual for Tropical Marine Resources, Second Edition.
Australian Institute of Marine Science, Townsville,
Australia.
Ethirmannasingam, S. (1996) Preliminary survey for Cambo-
dian seagrass resources. Unpublished report to Wetlands
International, Phnom Penh, Cambodia.
FFI—Fauna & Flora International (2013) Protection and
management of marine turtle habitat in Cambodia’s rst marine
protected area. Unpublished nal report to the USFWS
Marine Turtle Conservation Fund. Fauna & Flora Interna-
tional—Cambodia Programme, Phnom Penh, Cambodia.
FiA—Fisheries Administration (2011) The Strategic Planning
Framework for Fisheries: 2010–2019 Cambodia. Fisheries
Administration of the Ministry of Agriculture, Forestry
and Fisheries, Phnom Penh, Cambodia.
Govindasamy, G., Arulpriya, M., Anantharaj, K., Ruban, P.
&R Srinivasan, R. (2013) Seasonal variations in seagrass
biomass and productivity in Palk Bay, Bay of Bengal,
India. International Journal of Biodiversity and Conservation,
5, 408–417.
Hemmings, M.A. & Duarte, C.M. (2000) Seagrass Ecology:
An Introduction. Cambridge University Press, Cambridge,
UK.
Johnsen, S. & Munford, G. (2012) Country Environment Pro le:
Royal Kingdom of Cambodia. Report by Euronet Consulting
for the European Union, Brussels, Belgium.
Leng P. (2013) Assessment of shing practices in marine
sheries management areas around Koh Rong and Koh
Rong Sanleom, Cambodia. Cambodian Journal of Natural
History, 2013, 113–114.
MFF—Mangroves for the Future (2013) Cambodia National
Strategy and Action Plan 2014–2016. Ministry of Environ-
ment and Mangroves for the Future, Phnom Penh,
46
© Centre for Biodiversity Conservation, Phnom Penh Cambodian Journal of Natural History 2014 (1) 37–46
Leng P. et al.
Cambodia.
MCC—Marine Conservation Cambodia (2011a) Koh Rong
Samloem and Koh Kon Marine Environmental Assessment:
Report on Marine Resources and Habitats. Report to the
Fisheries Administration from Marine Conservation
Cambodia, Koh Rong Samloem, Cambodia.
MCC—Marine Conservation Cambodia (2011b) Koh Rong
Samloem Community Fishery Socio-demographic Survey: April
2011 Update. Report to the Fisheries Administration from
Marine Conservation Cambodia, Koh Rong Samloem,
Cambodia.
Nagelkerken, I., van der Velde, G., Gorissen, M.W., Meijer,
G.J., van’t Hof, T. & den Hartog, C. (1999) Importance of
mangroves, seagrass beds and the shallow coral reef as
a nursery for important coral reef shes, using a visual
census technique. Estuarine, Coastal and Shelf Science, 51,
31–44.
Nelson, V. (1999) Draft Coastal Pro le: Volume I, II : The Coastal
Zone of Cambodia: Current status and Threats. Ministry
of Environment/DANIDA Coastal Zone Management
Project, Phnom Penh, Cambodia.
Ouk V., So N. & Lim P. (2010) Seagrass diversity and distri-
bution in coastal area of Kampot Province, Cambodia.
IJERD—International Journal of Environmental and Rural
Development, 2010, 112–117.
Sereywath P. & Sokhannaro H. (2003) Seagrass meadow
and green turtle in Cambodia. In Proceedings on the 4th
SEASTAR2000 Workshop, December 11-13, 2003, Bangkok,
Thailand (ed. N. Arai), pp. 36–39. Graduate School of Infor-
matics, Kyoto University, Japan.
SCW—Save Cambodia’s Wildlife (2006) Atlas of Cambodia:
National Poverty and Environment Maps. Save Cambodia’s
Wildlife, Phnom Penh, Cambodia.
Short, F.T., McKenzie, L.S., Coles, R.G. & Vidler, K.P. (2001)
SeagrassNet Manual for Scienti c Monitoring of Seagrass
Habitat. Department of Primary Industries, Queensland
Government and Marine Plant Ecology Group, Cairns,
Australia.
Short, F., Carruthers, T., Dennison, W. & Wayco , M. (2007)
Global seagrass distribution and diversity: a bioregional
model. Journal of Experimental Marine Biology & Ecology,
350, 3–20.
Skopal-Papin, M. (2011) Koh Rong, Koh Rong Samloem and Koh
Koun Marine Fisheries Management Area: 3rd Draft for Zoning
Proposal. Report to the Fisheries Administration, Depart-
ment of Fisheries Conservation, Phnom Penh, Cambodia.
Smyth, D. (2006) Dugong and Marine Turtle Knowledge
Handbook: Indigenous and Scienti c Knowledge of Dugong
and Marine Turtles in Northern Australia. North Australian
Indigenous Land & Sea Management Alliance, Darwin,
Northern Territory, Australia.
Tana T.S. (1995) Status of marine biodiversity management
in Cambodia and possible measures for e ective conser-
vation. Paper prepared for the Global Biodiversity Forum, 4-5
November 1995, Jakarta, Indonesia.
UNEP—United Nations Environment Programme (2008)
National Reports on Seagrass in the South China Sea, Cambodia.
UNEP/GEF/SCS Technical Publication No. 12. United
Nations Environment Programme, Bangkok, Thailand.
Unsworth, R.K.F., Bell, J.J. & Smith, D.J. (2006) Tidal sh
connectivity of reef and seagrass habitats in the Indo-
Paci c. Journal of the Marine Biological Association of the
United Kingdom, 2007, 1287–1296.
Wiswedel, S. (2012) Hippocampus spinosissimus. In IUCN
Red List of Threatened Species. Version 2012.2. H p://www.
iucnredlist.org/details/10084/0 [accessed 14 May 2013].
About the Authors
LENG PHALLA has worked with FFI’s Cambodia
Programme since July 2010. She joined as a volun-
teer for the Cambodian Elephant Conservation
Group before becoming a part time Project Assistant.
She supported o ce-related activities and CECG
members to conduct eld studies to gather accurate
data on elephants and write reports. In August 2012,
Phalla became a Project O cer on FFI’s Marine Turtle
Conservation Project, taking part in research, project
support and administration, community engagement
and awareness-raising. Phalla has a BSc in Biological
Science and an MSc in Biodiversity Conservation from
the Royal University of Phnom Penh, including socio-
economic research on small-scale coastal sheries.
SOPHIE BENBOW has been working in conservation
with a focus on sustainable sheries management
since 2007. She has an MSc in Conservation from
University College London and was previously based
in Madagascar for ve years where she led research
into the southwest octopus shery, and supported an
assessment of seagrass within a newly formed Locally
Managed Marine Area. Sophie joined FFI in 2013 and
provides remote technical support to FFI’s marine
projects in countries throughout Asia.
BERRY MULLIGAN has a degree in Ecology from
the University of East Anglia, UK. He rst came to
Cambodia in 2006 to conduct a three-month eld
study of large waterbirds in Mondulkiri Province,
and research on Manchurian reed-warbler Acroceph-
alus tangorum and other passerines on the Tonle Sap
oodplain. Since then he has predominately worked
with small NGOs in Central America, particularly on
marine turtle conservation and research. He moved
to Cambodia in 2010 and is currently working with
the Fisheries Administration and partners to support
the establishment of a Marine Fisheries Management
Area in the Koh Rong Archipelago.
Article
Full-text available
Seagrasses – a group of foundation species in coastal ecosystems – provide key habitat for diverse and abundant faunal assemblages and support numerous ecosystem functions and services. However, whether the habitat role of seagrasses is influenced by seagrass diversity, by dominant species or both, remains unclear. To that end, we sought to investigate the specific seagrass characteristics (e.g., species diversity, seagrass traits) that influence tropical fish assemblages, and place this in the context of small-scale fishery use. We surveyed seagrass variables at 55 plots, nested within 12 sites around Zanzibar (Tanzania) in the Western Indian Ocean, and used Baited Remote Underwater Video (BRUV) systems to assess fish assemblages across plots. Using linear mixed models, we reveal that seagrass structural complexity and depth were the best predictors of fish abundance, with higher abundance occurring in deeper meadows or meadows with high canopy, leaf length and number of leaves per shoot. Moreover, an interaction between seagrass cover and land-use was the best predictor of fish species richness, where sites closer to human impacts were less affected by cover than sites with lower human impact. Overall, models with seagrass species richness or functional diversity as predictors poorly explained fish assemblages. Fish taxa that were important for small-scale fishery sectors (e.g., emperors, snappers, rabbitfish, and parrotfish) were primarily driven by seagrass structural complexity. Our results provide a unique analysis of the relationship between seagrass habitat and its associated fish assemblages in that we show that seagrass species diversity had little effect on seagrass fish assemblages, which instead appear driven by specific seagrass traits and seagrass cover. If conserving high value species that support adjacent fisheries is the priority for protecting seagrass meadows, then seagrass areas should be chosen with high cover and structural complexity that are in deeper waters. Any conservation measures also need to balance the needs of fishers that use the resources supported by seagrasses.
Article
Full-text available
Seagrass meadows are valuable habitats having economic and ecological importance in coastal ecosystem. The major seagrass meadows in India exist along the southeast coast of India, particularly in Palk Bay region. The dominant seagrass species of this region was Cymodocea serrulata and Syringodium isoetifolium and these two species were taken for the survey. In this study, a survey was carried out for a period of two years from August 2009 to November 2011 on the seasonal and spatial variability of these two seagrass species. There was a distinct seasonal and spatial variation in the total biomass, productivity and above ground biomass, leaf canopy height and shoot density of these two species between the stations. The seasonal variation in the biomass, productivity, leaf canopy height and shoot density could be influenced by the abiotic variables and the nutrient factors. Results conclude that the particulate organic carbon, inorganic phosphate and total organic nitrogen (p>0.001 level) influenced the enhancement of biomass, productivity, leaf canopy height and shoot density. Increase in seagrass growth was observed in the monsoon season, due to optimum temperature, low salinity, pH and addition of nutrients.
Article
Full-text available
The nursery function of various biotopes for coral reef fishes was investigated on Bonaire, Netherlands Antilles. Length and abundance of 16 commercially important reef fish species were determined by means of visual censuses during the day in six different biotopes: mangrove prop-roots (Rhizophora mangle) and seagrass beds (Thalassia testudinum) in Lac Bay, and four depth zones on the coral reef (0 to 3 m, 3 to 5 m, 10 to 15 m and 15 to 20 m). The mangroves, seagrass beds and shallow coral reef (0 to 3 m) appeared to be the main nursery biotopes for the juveniles of the selected species. Mutual comparison between biotopes showed that the seagrass beds were the most important nursery biotope for juvenile Haemulon flavolineatum, H. sciurus, Ocyurus chrysurus, Acanthurus chirurgus and Sparisoma viride, the mangroves for juvenile Lutjanus apodus, L. griseus,Sphyraena barracuda and Chaetodon capistratus, and the shallow coral reef for juvenile H. chrysargyreum,L. mahogoni , A. bahianus and Abudefduf saxatilis. Juvenile Acanthurus coeruleus utilized all six biotopes, while juvenile H. carbonarium and Anisotremus surinamensis were not observed in any of the six biotopes. Although fishes showed a clear preference for a specific nursery biotope, most fish species utilized multiple nursery biotopes simultaneously. The almost complete absence of juveniles on the deeper reef zones indicates the high dependence of juveniles on the shallow water biotopes as a nursery. For most fish species an (partial) ontogenetic shift was observed at a particular life stage from their (shallow) nursery biotopes to the (deeper) coral reef. Cluster analyses showed that closely related species within the families Haemulidae, Lutjanidae and Acanthuridae, and the different size classes within species in most cases had a spatial separation in biotope utilization.
Article
Full-text available
10 pages, 5 figures. The effect of burial due to sudden sediment loading was examined in a mixed Philippine seagrass meadow through the experimental deployment of sediment (0, 2, 4, 8, and 16 cm deposited over the experimental plots). The responses in shoot density, vertical growth, and branching of the species present were assessed 2, 4, and 10 mo following disturbance. Shoot density responses were strongly species-specific. The large Enhalus acoroides maintained shoot density at all burial treatments, and only showed evidence of decline by the end of the experiment. Thalassia hemprichii and, to a lesser extent, Cymodocea rotundata showed a sharp decline in shoot density even at moderate burial treatments, from which they failed to recover. The accompanying species (Halodule uninervis, Syringodium isoetifolium, and Cymodocea serrulata) showed an initial decline in shoot density followed by recovery. The small Halophila ovalis showed an opportunistic growth in plots receiving intermediate (buried by 4 and 8 cm sediment) disturbance, reaching shoot densities well in excess of those on control plots. The results suggest a pattern of species loss following disturbance by sediment burial corresponding to the sequence, T. hemprichii -> (C. rotundata, S. isoetifolium, H. uninervis) -> C. serrulata -> E. acoroides. Vertical growth increased significantly for all species with differentiated vertical shoots, except C. serrulata. The examination of the time course of vertical growth imprinted on the shoots of the dominant species, T. hemprichii, revealed a rapid response to burial through increased internodal length, which was maintained over 8 mo following the disturbance. The resulting cumulative vertical growth along the experiment was linearly correlated with the degree of burial imposed on the plants. Branching of vertical shoots also increased significantly (73 to 96%, depending on the species) with burial. Experimental burial induced changes in shoot age distribution of some of the species, involving rearrangements, through selective mortality or recruitment, of the contribution of young shoots to the populations. The results obtained show major differences in species response to small-scale disturbance, closely linked to predictions derived from consideration of species growth rate and size, and provide evidence of the importance of small-scale disturbance in the maintenance of multispecific seagrass meadows. This research was funded by the STD-3 programme of the Commission of the European Union (project TS3*-CT94-0301). Peer reviewed
Article
The present study considered the influence of the tide on shallow water fish assemblages within the Wakatobi Marine National Park, Indonesia. Timed underwater visual observations were made across a gradient of intertidal to subtidal habitats from near-shore to reef crest at different tidal heights. Transient fish were found to dominate shallow water fish assemblages and the assemblage composition varied with tidal state. Fish assemblages were more diverse and abundant at higher tides in both coral and sea grass habitats, however, this was more pronounced within sea grass habitats. A tidal reduction from [approximate]2.0m to [approximate]0.8m (above chart datum) corresponded to a 30% reduction in fish abundance, while species richness also significantly decreased from 13.5 to 10.8 species per standardized timed observation. Fifty fish groups were reported from sea grass habitats with the most abundant being from the Engraulidae family and Lethrinus harak, which form important local subsistence fisheries. This research confirms the importance of tidal changes in structuring the fish fauna of Indonesian sea grass habitats and underlines the connectivity that exists between these habitats and nearby coral reefs.
Article
December 11-13, 2003, Bangkok, Thailand
Report of Dugong and Seagrass Survey in Vietnam and Cambodia Anonymous (2014) Seagrasses: the Least Understood of the Coastal Canaries. Biodiversity Information Sharing Service (ASEAN Clearing House mechanism)
  • K Adulyanukosol
Adulyanukosol, K. (2002) Report of Dugong and Seagrass Survey in Vietnam and Cambodia. Phuket Marine Biological Center, Phuket, Thailand. Anonymous (2014) Seagrasses: the Least Understood of the Coastal Canaries. Biodiversity Information Sharing Service (ASEAN Clearing House mechanism). Htt p://chm.asean-biodiversity.org/index.php?option=com_content&view=a rticle&id=169&Itemid=169 [accessed 1 May 2014].