Impacts of Land-use on Bunut Lake, Sarawak, Malaysia
Alexander K. SAYOK1, LAU Seng1, and Richard Dagang BELANDA2
1. Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia
2. University of Technology Swinburne, Kuching, Sarawak, Malaysia.
{ksalexender@ibec.unimas.my}
Abstract: Loagan Bunut, a natural inland lake, is located
from destruction.
in the Loagan Bunut National Park (LBNP), Sarawak,
The main source of water to the lake is the inflow
Malaysia. It is not only scenic but teemed with various
from Teru River via Bunut River. It also receives water
species of fauna at different periods of the year often
rainfall and inflow from Bunan River. The lake
associated with fluctuating levels of the lake and
discharges
phenological cycle of the surrounding vegetation.
evapotranspiration.
water
through
Bunut
River
and
Physical evidences of past human habitations which are
still intact and the present use of ancient fishing
implements by local Berawans along with their cultural
practices in addition to the various biodiversity in the
surrounding set LBNP as a potential tourism destination.
Its upper catchment area was subjected to logging
activities in early 1980s followed by land conversion to
oil palm plantations. Several studies showed that these
land use changes have caused adverse impacts on the
river system and threatening the survival of the lake.
Some efforts are being made to mitigate these impacts
and had yield promising results. Suggestions are being
made to ensure that the lake is sustainable.
The LBNP is one of the three demonstration sites
Keywords: Disappearing lake, lake rehabilitation
efforts, land use impacts, Loagan Bunut Malaysia
1. Introduction
The Loagan Bunut National Park (LBNP), covering an
area of 10,736 hectares (ha), is located between the
Tinjar and Teru Rivers in the upper reaches of the Baram
River basin in northern part of Sarawak (Map1). The
Park was gazetted in 1990 primarily to protect the lake
known as Loagan Bunut and its peat swamp forest along
with its surrounding ecosystems. Located at the center
of the Park, this 650-ha lake is considered as the biggest
natural freshwater lake in Sarawak offering a stunning
beauty and teeming with abundant wildlife. This lake can
act as a huge manometer, absorbing flood water
cushioning downstream communities and their properties
selected
in
Malaysia
for
the
Project
entitled:
Conservation and Sustainable Use of Tropical Peat
Swamp Forests and Associated Wetland Ecosystems
which was initiated by the Government of Malaysia and
supported
by
United
Nations
Development
Programme/Global Environment Facility (UNDP/GEF)
and the Danish International Development Assistance
(Danida). Started in June 2002, this project aims to
ensure the conservation of globally significant genetic
species and ecosystem diversity within the PSF through
development and implementation of management plans.
For LBNP, the conservation of the lake seems to be the
top priority.
2. Land Uses around Loagan Bunut
Since the lake is dependent on Teru River as its main
water source, land-use changes in the upper watershed
Initially all surrounding areas including the Teru
watershed were mostly forested. As the Berawan
area will have great impacts of the lake particularly those
related on the water quality.
community came to inhabit the area near to the lake, they
started small-scale shifting cultivation on the dryland
Table 1: Distribution of the plantation estates within the
forest area. They also established small scale fruit
upper Teru Watershed
gardens. Their activities mainly concentrated at the
lowland areas nearby the lake. Timber harvesting started
in the peat swamp forest (PSF) areas in the late 1950s.
Later when timber in the PSF were exhausted, logging
moved into the lowland mixed dipterocarp forest in the
southern areas of the Teru watershed in early 1980s
followed by large-scale commercial agriculture mainly
oil palm plantations (Map 2) transforming the landscape
of the Teru watershed.
Plantation Estates
Gross Area
(hectares)
Planted areas
hectares
%
Sg. Lelak
Loagan Bunut
3,734
4,190
813
3,484
Bukit Limau
KSM
4,827
5,000
109
250
5,000
8,000
15,105
4,691
8,000
1,850
93.8
100
12.2
38,441
19,197
49.9
Yayasan Melaka
Pelita Tangkas
Baram Tinjar
Total
21.7
83.1
2.3
5.0
3. Impacts of land-use on Loagan Bunut
Transformation of the cover of the Teru watershed,
had caused many changes to the receiving waters
downstream (Teru River, and Bunut River and Loagan
Bunut). Various studies conducted in LBNP (e.g. AWEVISKON-UNIMAS 2003; Lau et al. 2006; Murtedza et
al. 2006; Noweg et al. 2006; Wan Sulaiman et al. 2006,
Bandang et al, 2007) and regular monitoring by the
Natural Resources and Environment Board (NREB) and
the UNDP/GEF project showed evidences reflecting the
seriousness of the sedimentation and eutrophication in
the lake.
3.1 Sedimentation rate
Map 2. Development projects in Teru watershed upstream
of Loagan Bunut National Park.
As main source of water in the lake is inflow from
Teru River via Bunut River, amount of suspended solids
carried in runoffs into the lake and deposited them at the
Since about 30% of the Teru watershed area is rugged
bed of the lake where the current is slowed down through
with thin and fragile soils, only 38,441 hectares (71% of
dissipation of flow. Sediment core from the lake by Hunt
total 54,300 ha) had been alienated to plantation estates.
et al (2006) indicated that the annual sedimentation rate
Out of these areas, 19,197 ha (50%) in 2006 were being
in the lake before the 1980s when the area was basically
under various stages of plantation development (Table 1).
undisturbed was estimated at 0.4 mm/y and to about 25
The land use changes, which brought about various
mm/y during the later years. This trend showed that
related activities, had over the years drastically altered
logging this area and then transforming it caused an
the state of the environment of the entire Teru watershed.
increase in sediment by about 62.5 times. Based on this
observation, they estimated that the lake will be silted
within less than 60 years.
The increase in the sedimentation rate in the lake
was most likely due to the increase in the frequency of
Another study by Lau, et al., 2006, found that the
inflow of water from Teru River. It was reported that the
daily sedimentation rate along Sg. Bunut was more than
frequency of the lake having low water level was much
2
2
40 g/m day while in Sg. Bunan was about 4 g/m /day and
2
in the lake proper it was almost 2 g/m /day (Fig. 2).
the lake received water from Teru River, there will be
accompanied by a new load of sediment. Therefore if
80
there is more frequent inflow of water from Teru River,
70
there will be more sediment input and hence the mean
60
Sed. Rate g/m2day)
higher in 2006/2007 than in 2004/2005 period. Each time
daily rate will be higher. This occurrence is closely
50
associated to the land use changes in the upper catchment
40
of Teru River. Massive conversion of forested area into
30
large scale plantations has altered the hydrological
20
balance. The difference between the maximum discharge
10
of Teru River and its base flow has increased and this
0
LB1
LB2
LB3
LB4
LB5
LB6
LB7
LB11
LB12
Sampling Station
created greater fluctuation in the water level of the river
which in turn influences the water level in the lake.
Fig 2 shows the average daily sedimentation rate at
different locations in the lake and its adjacent
3.2
Sedimentation pattern
The sediment deposition pattern in the lake reveals
waterways.
two major inflows into the lake. The inflows are from
A follow-up study by for the period between
Bunut River (from the east) and Bunan River (from the
November 2005 and August 2007 (Dagang, et. al, 2007)
west). The two rivers converge in the lake and the energy
showed that the sedimentation rates in the lake proper
of the flow was repelled towards the north/north-west.
have increased (Table 2).
From various simulations
This was observed by the sedimentation pattern where
based on this sedimentation pattern, he speculated that
moderate rate of deposition was recorded towards the
the lake will be isolated from Bunut River in half the
north-western side of the lake (Map 3). This path also
period.
suggests that the inflow from Bunut River was much
higher than that of Bunan River. The rates of
Table 2: The mean sedimentation rates obtained from
sedimentation at the mouth of the Bunut River were
two study periods
relatively higher that the other sites in the lake. Lau et al,
2007, estimated that at this rate of sedimentation (19.32
Equivalent
Station
7 / LB5
11 / LB4
13 / LB3
19 / LB7
21 / LB6
Study 1
(Lau, et al., 2006)
Mar 2004 – Sep
2005
1.93
1.34
1.54
1.00
3.71
Study 2
g/m2/day), and assuming the bulk density of the sediment
( Dagang, et.al.,
2007)
Nov 2005 – Aug
2007
is 1.1 g/cm3 the thickness of the sedimentation of 0.175
6.72
7.78
7.07
5.40
6.35
mm or 63 mm a year which could result in elevation of
2.0 m at Bunut the river mouth within 30 years. At this
level, the lake will be isolated from Bunut River.
The turbidity of the water indicates the amount of
suspended solids in the water. The suspended matter
Bunut River
Sediment Fluxes
could be the soil particles as a result of soil erosion or it
> 14 g/m2day
could be due to the suspended alga cells in a eutrified
10 – 14 g/m2day
water body. In this study it was noticed that the higher
6 – 10 g/m2day
turbidity values were recorded coincide with the rainfall.
< 6 g/m2day
This indicates that the main source of turbidity of the
lake was from soil particles washed down by the surface
runoff. The absence of high DO contents during the
afternoon (peak photosynthetic period) suggests that the
Bunan River
suspended matter was unlikely to come from the
algae/planktons cells.
Map 3.
Average daily sedimentation rate at different
locations in the lake and its adjacent waterways along with
their general flowpaths.
3.3.3
Electrical Conductivity
The peat swamp forest, in general, has low electrical
conductivity as most of the discharges have high amount
3.3
Water Quality of Loagan Bunut
The water quality monitoring in the lake was
specifically for detecting the changes in the dissolved
oxygen level (indicating the oxygen demand of the lake),
the fluctuation in the turbidity (indicating the influx of
water with suspended solids from Sg. Teru), the pH
levels (differentiating from the peat water and the water
from Sg. Teru), electrical conductivity (indicating the
influx of inorganic ions) and temperature (estimate the
evaporation rate).
3.3.1
Dissolved Oxygen
The dissolved oxygen levels in the lake were
generally low (< 4 mg/L). The daily pattern showed that
The DO reaches its lowest during the dawn (06:00 hr)
and highest during the afternoon. However, this general
pattern will be overwritten by the rainfall pattern. If there
is an influx of water from Sg. Teru, there will be an
increase in the DO level or during the rain event in the
lake, the perturbation caused by the raindrops will
increase oxygen diffusion into the water body. There was
no excessive alga growth in the lake as the oxygen
content in the lake did not indicate high level of
photosynthesis as it would have been if there were
extensive alga growths.
3.3.2
Turbidity
of organic matter (dissolved and suspended). The
dissolved organic matter in water is not an electrolyte
and hence does not conduct electricity. The electrical
conductivity at LBNP#2 (Pulau Tengah) was low
(between 30 and 50 µS/cm). In normal natural stream,
the conductivity is between 60 and 130 µS/cm. The
water in the lake is mostly depleted of inorganic ions. It
is suspected that the dissolved organic matter such as the
fluvic and humic acids may be the sorbent for the
inorganic ions such as Ca2+, Mg2+ and CO32-. The
frequent influx of river water from Sg. Teru gave rise to
the sporadic increases in the conductivity.
3.3.4
Water Temperature
The water temperature of the lake is expected to be
high during the day and low during the night. The
temperatures recorded were between 26 and 33oC. The
temperature is expected to be higher during the dryer
periods and the water of the lake becomes shallow. The
changes in the water temperature were gradual and hence
this would not adversely affect the aquatic life. There
were occasions where the temperature oscillated within
2oC. If sudden drop of temperature occurs in the water,
some aquatic life may experience thermal shock and it
may result in substantial fish kill. However, there was no
incidence of fish kill reported in the lake.
Studies by AWE-VISKON-UNIMAS (2003) and
3.3.5 Eutrophication
The water column and the top sediment layers in
Lau et al. (2006) on the water quality of Loagan Bunut
the lake were found to be generally anoxic; as such the
and surrounding area recorded low levels of dissolved
high production of ammonia and methane were
oxygen in the lake, relatively high ammoniacal nitrogen
expected. The ammonia levels in the water column
and high sediment loads from the Teru River.
ranged from 0.12 to 1.08 mg/L. Peat discharges were
The water quality index for the study area was found
observed in most of the lake area (with the colour
to be under Class III. Although the lake water was
ranging from 107 to 240 Hazen unit while the coliform
described as oligotrophic (low nutrient content) during
bacteria counts in the lake were low (less than
high flows, the potential seriousness of eutrophication in
500cfu/100mL).
the near stagnant Sg. Bunan and the lake waters during
extreme low flows, as the nutrient levels in the fertile and
4.
Impacts of Sediments
organic-rich
waters
become
concentrated
through
evaporation. In the Bunan River, the sedimentary organic
Potential impacts of sediment on the biological
matter was reported to be in the range of 12.3–18.8%,
especially the aquatic organisms including fish was
relatively high compared to the typical levels of 4–8% in
discussed by Nyanti et al (2006) and amphibians by Das
the sediment of tropical streams (Lau et al. 2006). The
(2006). The consequences of the threats are inter-related.
turbidity of the water ranges from 20 to 90 NTU
The silting up of the lake directly threatens its existence
indicating that suspended matter in the lake settled quite
because
sediment
substantially for the water to have a turbidity of 20 NTU.
contributes to the flourishing of aquatic plants, which
The relatively high turbidity at 90 NTU indicates that
subsequently consolidates the deposited sediment and
there were substantial amount of suspended matter
accelerates the sedimentation rate further, leading to the
brought in by the incoming water from Bunut and Teru
reduction of the life span of the lake.
Rivers.
nutrients
accumulation
in
the
The sedimentation in the lake has also brought along
The accumulation of nutrients from the domestic
the sedge grass (Cyperus haspan), which has established
wastewaters, fertiliser run offs and the decaying biomass
itself in the lake (Bulan, et al., 2006). This grass is
in the lake cause eutrophication in the lake, promoting
believed to contribute to more sedimentation, leading to
alga growth, deteriorating the water quality and
the depletion of dissolved oxygen and release of
depreciating the aesthetic value of the lake as the water
nutrients from the decaying biomass of the dead grass.
turns greener.
Another finding indicative of continuous sediment input
The level of heavy metal in the lake sediment was
to the Loagan Lake was reported by Wan Sulaiman et al.
studied (Lau, et al. 2006). The level of Pb in the lake
(2006). The study highlighted that despite the large water
sediment was relatively high (20–28mg/kg). The most
storage capacity of the PSF, there was little base flow
probable source of Pb in the lake was the leaded petrol
into the lake. This is probably due to the clay deposition
used to power the outboard engines or boats that navigate
in the outer margin of the lake/PSF and the accelerated
in the lake and the adjacent waterways. The threat of Pb
sedimentation of the lake bed that prevent flow between
poisoning to the aquatic life may not be of an immediate
the two entities. Future accelerated sedimentation would
concern. Metal such as Pb is toxic to the aquatic
cause even greater hydrological separation between the
organisms and it may be accumulated in fish. The
lake and the PSF apart, apart from shortening the
toxicity of Pb will be transferred to those who consumed
lifespan of the lake.
the contaminated fish. The current level of Pb in the
.
sediment is not alarmingly high yet.
4.2 Accumulation of nutrients, heavy metal and other
pollutants
5.
Efforts towards rehabilitation of the lake
Loagan
Various efforts had been made by the PSF Project to
sustain Loagan Bunut and the watershed as a whole. An
Bunut.
The
immediate
measures
being
considered for minimising the sediment loading include:
a)
Restricting the flow of Bunut River by
environmental profile of LBNP were greatly enhanced
constructing a sluice gate across Bunut River
through a Multi-Disciplinary Assessment undertaken in
near the confluence of Teru River;
2003 by the PSF Project and the Loagan Bunut Scientific
b)
Deepening certain parts of Bunut River to serve
Expedition in 2004, formed the crucial first step towards
as a sediment sink to trap the bed load materials;
safeguarding the natural resources.
and
As efforts towards conservation of the lake require
involvement
of
various
stakeholders,
awareness
campaigns were launched to highlight the threats to the
c)
Creating an in-stream wetland that can disperse
the
flow of
Bunut
River
and promote
sedimentation to protect the lake.
lake and how its lifespan could be prolonged. Special
Constructing any physical structure across Bunut
events were organised to deepened understanding and
River to prevent the influx of sediment would eventually
concern for the lake including production of various
make Loagan Bunut a permanent lake and the entire
information material such as a brochure entitled “Save
ecosystem of the existing lake would be changed
Loagan Bunut”.
drastically. The water quality of the lake would be
A special task force, comprising the primary
degraded to such an extent that it would become an
stakeholder agencies, officers from upstream oil palm
oxidation pond. This option would most likely lead to
plantations, local longhouse leaders and fishermen, and
another ecological disaster.
head by the Natural Resources and Environment Board
The deepening of the river channel to trap the bed
(NREB), Sarawak was established to look into the
load of the incoming water from Sg. Teru may be
pollution problems and mitigation measures.
acceptable in terms of ecological sustainability although
Since the upstream development activities are a
there could be slight disturbances to the river channel
major contributor of the sedimentation and agrochemical
during the dredging. Nevertheless, the effectiveness of
pollution in the lake, environmental education and
this measure is uncertain. It calls for further detailed
training programmes were conducted for oil palm
investigation on its implementation and the design of the
developers to promote practices that would reduce the
channel modification.
impact of agricultural development.
The construction of an in-stream wetland at the point
Monitoring of the water quality and sedimentation
of entry from Sg. Bunut to the lake seems to be a viable
form very important components in the Management
option. The concept of in-stream wetland for non-point
Plan for Loagan Bunut National Park. It also provides
sources control has been practiced in other places such as
guidelines for improvement of the lake water quality
in Ohio, (Mitsch et al, 1993) and in Illinois (Mitsch,
through recommended activities in the park as well as
1995) and. Constructing the in-stream wetland would not
upstream of the lake.
change the ecosystem of the lake given that some parts
of the lake are vegetated wetlands. More detailed study
should be undertaken to ensure an effective and
5.1 Corrective measures
Given that sedimentation is the major threat,
immediate measures were required to control the influx
of sediment into the lake. Land clearing for large-scale
agriculture
schemes
and
the
continuous
ecologically sustainable approach be adopted for
sedimentation control in Loagan Bunut.
Presently none of the three options has been
timber
implemented by the Project. However, a “Save Loagan”
harvesting activities at the headwater areas of the Teru
mini project costing RM2.0 million had been proposed.
River watershed constantly provide loose soils in the
This project is to dredge the lake bed to 1-m deep along
surface runoffs to the river, which would be deposited at
the mouth of Bunut River and along the corridor. The
excavated bed will be dumped along the nearby edges of
these facilities. More often than not, these structures are
the lake and making an earth embankment of 1.5m high
demolished either by draining or filling them and
at Bunut River mouth to retain a minimum water level of
converted to agriculture or housing areas. In efforts to
1-m in the lake. This will also requires diverting Purun
conserve the lake, it is important that these riparian
and Bunan Rivers into the dredged areas, away from the
wetlands or swamps are preserved and where necessary,
Bunut River mouth.
new wetlands be constructed at suitable locations to treat
the non-point sources of pollutants.
Communities living around the lake are currently
5.2 Preventive measures
Corrective measures may not be able to sustain and
discharging their household wastewater directly into the
protect the lake for a long period and therefore, it is vital
lake. Prior to discharging the wastewater into the lake, it
to incorporate some preventive measures, particularly at
should be treated to an acceptable level first. There are
the headwater areas of the Teru River watershed.
several systems that may be suitable for small
Controlling the non-point sources at the headwater areas
decentralised treatment. Ecological sanitation system has
should be the main focus. Among the approaches that
been proven to be useful for solving sanitation problem
could be adopted are:
in rural areas (Jenssen, 2004; Lau, 2004b). A pilot
a)
b)
c)
Preserving and rehabilitate the riverine buffer
ecological sanitation systems (ECOSAN) had been
strip of appropriate size;
installed at the LBNP Headquarters and the lodging
Implementing high standard of soil conservation
houses. A modified ECOSAN had been proposed for the
and management practices;
27-door longhouse, Rumah Panjang Loagan Bunut,
Preserving
natural
riparian
wetlands
and
located at the source of Bunan River. The household
constructing more in-stream wetlands network
solid waste disposal system has also been coordinated to
at strategic locations along Teru River and its
prevent these wastes from entering the lake.
tributaries;
d)
Constructing point sources treatment facilities
for domestic wastewaters and solid wastes; and
e)
Promoting
community
awareness
and
5.3 Institutional involvement
It has been shown many times in all parts of the
world
that
many
environmental
conservation
participation in Loagan Bunut environmental
programmes failed whenever there was no community
conservation effort.
participation.
The environmental conservation of
The main focus of the preventive measures is on the
Loagan Bunut will need the support and active
sedimentation issue. The two sectors that are directly
participation of the local communities as well as other
related to this issue are the agriculture and the forestry
related stakeholders. All relevant parties had been made
sectors. Buffer strips along all waterways, irrespective of
to be aware on the need to protect and conserve the lake
their sizes, are important to control sedimentation and
and to understand how the could contribute for the
protect
Promoting
mutual benefit of all. Regular awareness seminars and
understanding and awareness of the need to protect the
community participation activities were conducted by
water environment among these stakeholders is the key
the Project in collaboration with various state agencies
to
such as the Forestry Department, NREB, Ministry of
the
river/stream
success
of
banks
erosions.
environmental
conservation
programmes. Besides allocating a buffer strip, the
planters and foresters should embark on the highest
Tourism and the Department of Agriculture.
The
Sarawak
environmental
legislations
are
quality practice in soil conservation and management
comprehensive and relevant for the protection of the
within their designated land.
environment. However, there are some areas such as
There are naturally occurring facilities to treat and
preserve our water. The riparian wetlands are among
regulations
on
domestic
effluent
discharges,
environmental impact assessment (EIA), environmental
monitoring and auditing that may require some fine-
activities upstream and willing to allow us to visit their
tuning. Due to the fragility of Loagan Bunut, Murtedza
plantations and give advice on how to reduce the losing
(2004) suggested that all land use activities within the
topsoil downstream. They are also willing to contribute
catchment areas of Sg. Teru be subjected to stringent
They are also willing to contribute fund to the any
scrutiny and assessments. It is important that all
projects towards improvement of the sedimentation and
environmental assessments, monitoring and auditing be
water quality in general such as the mini project on
conducted professionally and complying to the highest
dredging the lake and the biological treatment of
standard. The implementation of EIA recommendations
blackwater and kitchen wastes from one of the
should be practical and effective, and they should also be
longhouses upstream.
monitored closely by the relevant state authorities.
Regulations and guidelines should be introduced to keep
7.
Conclusion
in check the domestic wastewaters quality standards.
The Loagan Bunut National Park being threatened.
6.
Results
The land development upstream particularly oil palm
estates contributes substantial sediment to the lake
Impacts of the various efforts undertaken on the
bottom. If left unchecked, it would turn into grassland
lake’s ecosystem especially in terms of water quality
and permanently disappear within 60 years. The main
improvement and reduction of sedimentation have not
outlet of the lake may also be silted up very quickly
been significant yet. In fact, the sediment rate had been
(within 30 years) and the entire ecosystem of lake will be
increased significantly during the two-year monitoring
altered completely. Hence it is of utmost important and
mainly because the land preparation activities for
of greatest urgency that a study should be conducted to
plantation establishment had entered to the more steep
determine the most appropriate ways to handle this threat.
slopes upstream. However, there are promising results
Short-term solution such as constructing in-stream
the established plantations had most of their bare areas in
wetlands along Bunut and Teru Rivers may provide some
between their palms and terraces were grown with cover
immediate relieve while waiting for the long-term
crops or had being overgrown with natural vegetation.
control measures to take effect.
With the newly established plantation following the same
The Project has worked closely with the relevant
trend, it is expected that the rate of sedimentation will be
stakeholders including local communities and oil palm
lower.
developers to identify the threats and challenges to the
As for the park headquarters, it was found that not
sustainability of the area and to take measures to address
only there were no evident of green algae bloom at the
these challenges. The Loagan Bunut National Park
outlet of the drains into the lake but no foul odour
Management Plan produced by the Project suggested that
emanating from the outlet and the lake water. Because of
the conservation of the lake could simultaneously
the encouraging results, the government had installed the
embark on two approaches. The first, the corrective
ECOSAN device for the rests of the building in the park.
measures are to address the immediate issue of
With budget permit, they will also install similar device
sedimentation. Construction of in-stream wetland and
for the lakeshore houses. The local Medical Department
sedimentation trough within the lake and along Bunut
had also installed a device to filter kitchen wastewater at
River seem to be ecologically favourable albeit more
each of the 27 households at Loagan Bunut Longhouse
detailed studies are required to ensure their effectiveness
instead of allowing it to directly flow into the drain and
and the sustainability. The second preventive measures
then into Bunan River.
would provide longer-termed solutions
Plantation owners were approachable and even
to soil erosion at the upstream regions and nutrients
acknowledged that the sediment are mainly due to their
enrichment in the lake. Prudent soil conservation and
management practices and preserving the riverine buffer
Sayok. Organic matter and heavy metals
strips and wetlands had been proposed. It is also
contents in the sediment of Loagan Bunut. In A.
recognised that participation of local communities and
A. Tuen et al. A Scientific Journey to the
stakeholders in all the environmental conservation
Loagan Bunut National Park, Sarawak. 2006b.
programmes are very important to ensure successful
implementation of these programmes.
7) W. J. Mitsch. Restoration of our lakes and rivers
with wetlands - an important application of
ecological engineering Water Science and
Acknowledgement
Technology Vol 31 No 8 pp 167–177 © IWA
We wish to acknowledge the park of Sarawak Forestry
Staff
for logistics support during fieldwork and the
Publishing 1995
8) Mitsch,
W.J., J.K. Cronk,
et al.
1993.
Research and Innovation Committee of Universiti
Phosphorus
Malaysia Sarawak for grants to present this paper.
productivity of constructed wetlands at the Des
retention
and
ecosystem
Plaines River Wetland Demonstration Project,
References
1991-92. Final Report to Wetlands Research
Inc., Chicago, IL, for U.S. Army Corps of
1) AWE-VISKON-UNIMAS.
Multi-Disciplinary
Engineers, Vicksburg, MS. 82 pp.
Assessment for the Loagan Bunut National Park.
9) M. Murtedza, N Bessaih., W. H. Wan Sulaiman,
Final MDA Report submitted to UNDP-GEF.
A. K. Sayok, Efransjah. Channel Profiles and
2003
hydrodynamics of streams and lake at the
2) R. B. Dagang, S. Lau, A. K. Sayok. Mapping
Loagan Bunut National Park, Sarawak. In A. A.
Sediment flux using cylindrical traps at Loagan
Tuen et al. A Scientific Journey to the Loagan
Bunut Lake. Proceedings of the International
Bunut National Park, Sarawak. 2006.
Conference
on
Natural
Environmental
Resources
Management
and
10) G. T. Noweg, W. H. Wan Sulaiman, M.
2007,
Murtedza, N. Bessaih, A. K. Sayok, Estimation
IKM/UNIMAS/NREB. Kuching.
of Sediment Yield in the Loagan Bunut Lake. In
3) C. Hunt, R.M., Banda, B. Bandang, A. U.
Ambun. Geology and soil survey of Loagan
A. A. Tuen et al. A Scientific Journey to the
Loagan Bunut National Park, Sarawak. 2006.
Bunut National Park. In A. A. Tuen et al. A
11) L. Nyanti, G. T. Noweg, A. K. Sayok. Riverine
Scientific Journey to the Loagan Bunut National
Fishery in Loagan Bunut National Park: Present
Park, Sarawak. 2006.
Status, Threats and Management Strategies. In
4) P.D. Jenssen, O.J. Skjelhaugen. Local ecological
solutions for wastewater and organic waste
treatment - a total concept for optimum
reclamation and recycling.
Proc. Seventh
A. A. Tuen et al. A Scientific Journey to the
Loagan Bunut National Park, Sarawak. 2006.
12) The Nature Conservancy. Handbook: The FiveS Framework for Site Conservation. 2003
International Symposium on Individual and
13) W. H. Wan Sulaiman, N. Bessaih, A. K. Sayok,
Small Community Sewage systems, Atlanta,
M. Murtedza, S. Lau. The soils of Peat Swamp
ASAE 18-94, pp. 379 - 387. 1994.
Forest and their role in regulating the baseflow
5) S. Lau, M. Murtedza, K. Apun, A. Bong, M. G.
Tay,
A. K. Sayok. Water Quality of Loagan
Bunut, Marudi, Sarawak. In A. A. Tuen et al. A
Scientific Journey to the Loagan Bunut National
Park, Sarawak. 2006a.
6) S. Lau, S. F. Sim, K. Devagi, A. Bong, A. K.
to the Loagan Bunut lake. In A. A. Tuen et al. A
Scientific Journey to the Loagan Bunut National
Park, Sarawak. 2006.