research article notes on the wild tomistoma populations...

Research ArticleNotes on the Wild Tomistoma Populations inWestern Sarawak Malaysian Borneo

Ruhana Hassan1 Rambli Ahmad2 Muhammad Amirul Arib Md Adzhar1

Mohd Izwan Zulaini Abdul Gani1 Anuar Ayob3 and Ramlah Zainudin4

1Department of Aquatic Science Faculty of Resource Science and Technology Universiti Malaysia Sarawak94300 Kota Samarahan Sarawak Malaysia2Sarawak Forestry Corporation Sdn Bhd Lot 218 KCLD Jalan Tapang Kota Sentosa 93250 Kuching Sarawak Malaysia3Department of Visual Art and Technology Faculty of Applied and Creative Arts Universiti Malaysia Sarawak94300 Kota Samarahan Sarawak Malaysia4Department of Zoology Faculty of Resource Science and Technology Universiti Malaysia Sarawak94300 Kota Samarahan Sarawak Malaysia

Correspondence should be addressed to Ruhana Hassan hruhanaunimasmy

Received 29 April 2016 Revised 8 September 2016 Accepted 21 September 2016

Academic Editor Panos V Petrakis

Copyright copy 2016 Ruhana Hassan et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Tomistoma schlegelii the Freshwater Malayan Gharial or Tomistoma (local name buaya jejulong) is secretive in nature thus verylimited information is currently available on its wild population especially in SarawakTheobjective of this study is to describe effortin assessing the Tomistoma wild populations in Ulu Sebuyau Samarahan and Serian western Sarawak Despite many challengesfaced this research has been successful at different levelsThere was no Tomistoma seen during day surveys (2014-2015) in tributaryof Samarahan River (Samarahan) Bunga-Baki River (Serian) and Kepayang River (Ulu Sebuyau) However the research teamcame across two incidents of Tomistoma captured by the local people (i) an adult male Tomistoma captured in February 2015 inpeat swamp area of Samarahan River tributary and (ii) a hatchling caught in Bunga-Baki River in March 2015 The sightings ofTomistoma in Kepayang River were reported by local people in February 2016 however no individual was captured The presenceof hatchling in Bunga-Baki River indicates that a breeding population is most likely to occur in the area and this gives hope forfuture conservation of Tomistoma in Sarawak All sampling sites recorded almost similar water quality parameters and landscapeof peat swamp areas which previous studies claimed to be the potential Tomistoma habitats The findings of this study should helprelevant state agencies to step up efforts related to conservation of Tomistoma in Sarawak

1 Introduction

Tomistoma schlegelii is also known by English common nameas Freshwater Malayan Gharial or False Gharial or Tomis-toma or Sunda Gharial whereas its local name in Sarawakis ldquobuaya jejulongrdquo This species is listed under InternationalUnion for Conservation ofNature (IUCN)Red List as vulner-able species [1] and listed underAppendix I of theConventionon International Trade in Endangered Species of Wild Floraand Fauna (CITES) In Peninsular Malaysia it is protectedunderWildlifeConservationAct 2010 It is also listed as a Pro-tectedAnimal in the SarawakWild Life ProtectionOrdinance

(1998) hence any hunting killing or selling of wild Tomis-toma in the state is prohibited

Literatures claimed that Tomistoma inhabits IndonesiaMalaysia possibly Vietnam andThailand [2] However verylimited information is known about Tomistoma in SarawakIn previous literature [3] reported that the status of its pop-ulation in Sarawak is unclear Other than that [4] had pro-duced a brief documentation on the existence of Tomistomain Sarawak in which it stated that this species can be foundin Ensengai River and Keluh River Meanwhile [5] producedreports on status and conservation on Tomistoma in South-east Asia but it reported very limited information regarding

Hindawi Publishing CorporationInternational Journal of EcologyVolume 2016 Article ID 4357623 7 pageshttpdxdoiorg10115520164357623

2 International Journal of Ecology

this species in Sarawak Furthermore the authors of [6]had compiled records of Tomistoma in Malaysia based onhistorical information and personal communications withscientists and local people They also highlighted that someTomistomas are currently being held in captivity for ex situconservation purpose in zoos and private farms Sixteenrivers in Sarawak had been claimed as habitats of Tomistoma(1917 to 2003) mostly with small number of Tomistomaindividuals Meanwhile the author of [7] had carried outTomistoma surveys in Engkilili Maludam National Parkand Loagan Bunut and it reported that one individual wasspotted in Engkilili but none in other areas His project haslimited success to verify the population status of Tomistomain Sarawak although the state hasmany potential Tomistomahabitats In terms of conservation priorities for Tomistomawild populations in its geographical range Sarawak is cate-gorized as ldquomoderate priorityrdquo [1]

Threats to Tomistoma came mostly from conversionof peat lands and pandan swamps (black water area withPandanus palms as the common flora) into agriculture [6]not due to hunting because the skin of Tomistoma is of lessvalue commercially and rarely people consume themeat Dueto secretive nature of this species attacks were most probablydue to opportunistic killing rather than aggressive nature ofhunting [8] The species is generally regarded as harmless tohumans although one case of attack on humans has beenconfirmed and others have been reported Similarly localpeople in Sarawak regarded Tomistoma as peaceful animalthat should be left alone but precaution steps are still neededto ensure safety of both humans and animals The species isgenerally regarded as harmless to humans with only smallnumber of reported human-Tomistoma conflicts in Sarawakbut could also cause human fatality for example the one thathappened in Tisak River [8]

People of Sarawak and Malaysia are so proud to be inthe map where Tomistoma is reported to be found yet thisspecies only appeared in folklores told by older generationliving in upper areas of selected rivers This paper describeseffortsmade to locate Tomistomawild populations inwesternpart of Sarawak (2014-2015) which hopefully will lead toTomistoma conservation actions in Sarawak in the nearfuture

2 Materials and Methods

21 Wild Populations Survey

211 Field Visits Paper [8] claimed that Sadong River andother nearby rivers in Simunjan and Ulu Sebuyau Sarawakhave many potential Tomistoma habitats Thus three siteshad been chosen (Figure 1) in Kepayang River (Ulu Sebuyau)tributary of SamarahanRiver and Bunga-Baki River (Serian)For Kepayang River surveys had been conducted in separatevisits that is 22ndndash25th July 2014 4th-5th December 2014and 3rd-4th February 2015 For Samarahan River field visitswere done on 14th and 15th February 2015 and for Bunga-Baki River the visits were done on 21st and 22nd March2015 All visits were carried out at the end of wet season(Northeast Monsoon) except for July 2014 trip for Kepayang

(km)0 100 200 300

Sarawak1

2

3

N

Figure 1 Sampling area in western part of Sarawak 1 SamarahanRiver 2 Bunga-Baki River and 3 Kepayang River

River Due to limited accessibility of all sites surveys werecarried out using boats in the rivers aswell as on foot along theriverbanks Many stretches of the rivers were impossible topass through due to overgrown weeds as well as the presenceof water gates to control water levels in the rivers possibly foragricultural purposes All Tomistoma surveys were carriedout during day time only

212 Study Area

Samarahan River (Samarahan) The Samarahan River is hugeriver with complex river connections with distance of morethan 70 km The downstream is connected directly to theSouth China Sea which experiences the intrusion of salt-water The upstream part (tributary of Samarahan River)comprises peat swamp and small riverine forestThree check-points were selected for water quality (WQ) measurement(Table 1) and Tomistoma surveys were done continuouslybetween checkpoints The selection of checkpoints werebased on natural river landscape observed The tributaryexamined during this survey runs from the main river(Samarahan River) through oil palm estates (about 6 km)followed by 4 km of small peat swamp forestThis tributary isapproximately 12 km long with width of less than 10m Thistributary has very limited access due to overgrownweeds andother floating vegetations Fishing seems to be of low intensitywith some nets and set hooks seen probably belonging toworkers of the plantation There was no boat traffic observedduring the survey No saltwater crocodiles were seen in thistributary although SamarahanRiver recorded a good numberof human-crocodile conflicts [9] which resulted in bothinjuries and fatality

Bunga-Baki River (Serian) The river is located near twovillages namely Bunga Village and Baki Village The river isrelatively small in the upstream area with approximately 2 to3m width in contrast to the wider size in the downstreamarea (4 to 5m) The Bunga River flows from the mountaininto Baki River and later to Sadong River The Bunga Riverflows through a forested landscape which has fairly clearwater and comprises many rocky streams The area is shadedwith the forest trees thus the air temperature is relatively

International Journal of Ecology 3

Table 1 Location and distance of rivers surveyed (on foot and using small boats)

River Checkpoint Start End Distance Tomistoma seen

Samarahan River

1 N 1∘25101584017410158401015840E 110∘32101584016010158401015840

N 1∘25101584001510158401015840E 110∘32101584038210158401015840 857m 0

2 N 1∘25101584001510158401015840E 110∘32101584016010158401015840

N 1∘24101584038510158401015840E 110∘34101584010910158401015840 293 km 0

3 N 1∘24101584038510158401015840E 110∘34101584010910158401015840

N 1∘23101584050310158401015840E 110∘3710158400210158401015840 543 km 0

Bunga-Baki River1 N 1∘12101584041410158401015840

E 110∘29101584053110158401015840N 1∘13101584025710158401015840E 110∘30101584036510158401015840 202 km 0

2 N 1∘13101584037310158401015840E 110∘30101584031810158401015840

N 1∘4101584050710158401015840E 110∘31101584029910158401015840 282 km 0

Kepayang River

1 N 1∘23101584001310158401015840E 110∘55101584013510158401015840

N 1∘22101584050710158401015840E 110∘55101584037910158401015840 129 km 0

2 N 1∘24101584010610158401015840E 110∘53101584026010158401015840

N 1∘23101584058810158401015840E 110∘53101584059810158401015840 101 km 0

3 N 1∘21101584027210158401015840E 110∘55101584038410158401015840

N 1∘20101584035410158401015840E 110∘55101584040610158401015840 525m 0

4 N 1∘19101584019410158401015840E 110∘56101584022010158401015840

N 1∘19101584019310158401015840E 110∘56101584031910158401015840 300m 0

lowastCheckpoints locationswherewater qualitymeasurements were carried out Tomistoma surveys were continuously carried out fromone checkpoint to anotherin each river

low (approximately 27∘C) Baki River flows through the peatswamps forest with one village situated at the side of the riverThe water has brown to black colour with slow flowing waterIn general the landscape flora and fauna compositions arecommon characters of a peat swamp area Two checkpointswere selected during the survey (Table 1) Small scale fishingis the main activity in the river Other than that villagersuse the river in daily activities for example as a means oftransportation to tend their small agricultural plots locatedalong the river banks There is no palm oil plantation yet inthe area although the construction of concrete buildings androads is rapid

Kepayang River (Ulu Sebuyau) Four checkpoints were select-ed (Table 1) The river is approximately 15 km in lengthbetween 2 and 4m in depth and approximately 10m inwidthWater fromKepayang River flows to Sebangan River and laterto Sadong River and eventually to the South China Sea Theriver has very limited excess that is only between 2 km and4 km can be explored by boat whereas the rest of the riveris covered by overgrown weeds ferns herbs (eg Hanguanamalayana) and other aquatic plants The river has brownto black colour water and slow flowing or sometime nearstagnant a common character of a peat swamp area Near tothis site there is a relatively large privately owned oil palmplantation Both local people and oil palm plantation workersdo subsistence fishing along the river

22 PhysicochemicalWater Quality (WQ) Parameters Select-ed physicochemical WQ parameters were measured at eachcheckpoint of the rivers (Table 1) Temperature and dissolvedoxygen (DO)weremeasured usingDOmeter HannaHI9146pH was measured using Hanna HI 8314 pH meter andturbidity was measured using Turbidity Meter 93703 Hanna

Instrument Water samples for chlorophyll a (Chl a) totalsuspended solids (TSS) and nutrients (ie nitrate nitriteammonia orthophosphate and silicate) were collected intriplicate at the checkpoints Chl a and nutrients were mea-sured in the laboratory using Hach Kit DR 2010 machine fol-lowing standardmethodwhereas TSSwas analyzed followingthe methods of [10] Habitat descriptions at study sites werealso recorded

23 Estimation of Aquatic Food Resource In this study avail-ability and estimation of aquatic food resource in each riverwere conducted using catch per unit effort (CPUE) approach[11] Passive fish captured method using three-layer gill nets(length and drop 15m times 15m stretch mesh size 12 cmand 75 cm deployment time between 7 am and 10 am)had been carried out accordingly in each river Fish catcheswere examined and identified to species level using availablereferences such as FishBase [12]

24 Local Knowledge This study employed semistructuredquestionnaires (testimonies and personal accounts related toTomistoma) on the local people Interviews were carried outonmixture of senior citizens and people from the new gener-ation within the sampling sites according to [13] Interviewswere based around the following topics and questions

(i) Where can Tomistoma be seen in this area name ofriverslakesareas

(ii) When was the last time Tomistoma was seen in thearea

(iii) When is the best time to see Tomistoma (wetdryspecial time of year)

(iv) What size of the Tomistoma that you saw (estimatesize adult juvenile young hatchling)


Figure 2 Tomistoma caught on 9215 in SamarahanRiver tributary(total length = 24m)

(v) How often do you see Tomistoma (every year wetdry every time out fishing)

(vi) Have you ever heard any stories of Tomistoma beingseen caught killed by someone else Which area wasthis dates details

(vii) Any nests or babies seen Have you heard any storiesof youngTomistoma (description nest habitat clutchsize nest type)

3 Results and Discussion

31 Survey Results In this study no Tomistoma was seen inall rivers (Table 1) although many stretches of the rivers seemto be potential Tomistoma habitats [8] Negative resultobtained during this study most probably is due to (i) thenature of Tomistoma who are very secretive and wary aboutany disturbances (ii) surveys done only during day light (iii)relatively short time spent on boat and foot surveys in eachriver and (iv) rivers involved being relatively difficult in termsof accessibility Day time search is believed to be among themain reasons of zero sighting thus future work will involvenight surveys

32 History of SightingsCaptured Tomistoma Table 2 sum-marized the history of captured Tomistoma and sightingsfrom local people

On 9th February 2015 one adult male Tomistoma(Figure 2 Table 2) had been captured in tributary of Sama-rahan River Local people claimed that some parts of Sama-rahan River supported small population of Tomistoma in the1970s and 1980s but they had never seen this animal in therecent years

Overall Tomistoma caught on 9th February 2015 seemedhealthy with good body weight-length proportion and hadgood skin condition and patterns However there was a slightinfection on both eyes in which left eye was relatively redin colour Debris of fishing net was found entangled in itsmouth Slight bleeding was also seen on the left and right

Figure 3 Tomistoma caught in March 2015 at Bunga-Baki RiverSerian (total length = 04m)

upper limb legs as a result from injuries most probably dueto constant struggle to free itself from the nets

Two individuals of Tomistoma hatchlings were capturedin two conservative years in Bunga-Baki River both in themonth of March 2014 and 2015 by a local resident The firsthatchling was released in the same habitat while the laterwas sent to Matang Wildlife Centre (Figure 3) The presenceof hatchlings in this area suggests that there is a breedingTomistoma population in the river which gives hope thatthere is a bright future for Tomistoma to thrive in this riverLocal fishermen interviewed (119899 = 5) and senior citizen (119899 =2) reported that they once saw adult Tomistoma in 2014

InKepayangRiver during 22ndndash25th July 2014 visit threeout of 10 male villagers who worked as porters and guidesclaimed that they have seen one young Tomistoma of approx-imately 1mduring their recent fishing trip Local villagers andoil plantation workers claimed that one Tomistoma carcasshad been found in May 2014 but the carcass could not belocated during the field visit There was also one reportedTomistoma sighting at Kepayang River during SFC AquaticSurvey Exercise on 28th July 2014 two days after the first visit

During the second trip to Kepayang River (3rd-4thFebruary 2015) a total of five villagers (119899 = 5) had beeninterviewed mixture of male and female from ethnic Ibanwho work as either small scale farmers or housemakers agedbetween 40 and 70 years This older generation had personalencounterwithTomistomabutmostly during 1970s and 1980sduring their boat journey to the nearest town They are all inagreement that there are Tomistomas in the Kepayang Riveralthough none of them meet this animal recently

On 16th and 17th of February 2016 local people hadinformed authors that Tomistomas were sighted in KepayangRiver but none were captured although effort to catchTomistoma using nets hook and line had been carried outIt is likely that the presence of aquatic weeds in the river givesadvantage to the Tomistoma to shelter themselves

33 Water Quality

331 Selected WQ Parameters Data obtained during thisstudy (Tables 3 and 4) serve as baseline WQ parameterssuitable for Tomistoma habitats in Sarawak Water temper-ature pH DO and turbidity readings (Table 3) are typicalof peat swamp ecosystem as reported by [14ndash17] Accordingto the National Water Quality Standards (Malaysia) except


Table 2 History of Tomistoma sightings or captured Tomistoma (2014ndash2016)

Locality Date Status Sizelife stage Person

Samarahan 922015Captured (119899 = 1)

Sent to Matang WildlifeCentre died in March 2015

24m Local people andvolunteers

Bunga-BakiRiver

March 2014Captured (119899 = 1)

Released by local people inthe same habitat

Hatchling Local people

1232015Captured (119899 = 1)

Sent to Matang WildlifeCentre

04m Local people

Kepayang River

July 2014 Sighting (119899 = 1) Subadult SFC AquaticSurvey team

July 2014 Carcass (119899 = 1) Adult Plantation workers1622016 Sighting (119899 = 1) Adult Local people1722016 Sighting (119899 = 1) Adult Local people

lowastSFC Sarawak Forestry Corporation

Table 3 Selected water quality parameters measured in situ

River Temperature (∘C) pH Dissolved oxygen (mgL) Turbidity (NTU)Samarahan 2667 plusmn 057 673 plusmn 047 503 plusmn 047 113 plusmn 012Bunga-Baki 2777 plusmn 068 420 plusmn 030 423 plusmn 025 440 plusmn 053Kepayang 2770 plusmn 026 559 plusmn 005 471 plusmn 001 283 plusmn 055lowastMean plusmn SD

Table 4 Selected water quality parameters measured ex situ

River Chlorophyll a(mgL) TSS (mgL) Ammonia

(mgL NH3ndashN)

Nitrate (mgLNO3ndashN)

Nitrite (mgLNO2ndashN)

Orthophosphate(mgL PO

4

3ndash)Silicate (mgL

SiO2)

Samarahan 049 plusmn 008 1933 plusmn 115 003 plusmn 001 002 plusmn 001 0002 plusmn 0001 022 plusmn 001 052 plusmn 010Bunga-Baki 045 plusmn 012 667 plusmn 416 002 plusmn 001 002 plusmn 001 0002 plusmn 0001 024 plusmn 004 037 plusmn 014Kepayang 057 plusmn 011 300 plusmn 100 021 plusmn 001 005 plusmn 002 0005 plusmn 0003 032 plusmn 024 079 plusmn 017lowastMean plusmn SD

for DO and pH WQ for the three rivers falls in Class I anindication of clean water which is suitable for conservationof natural environment as well as habitats for very sensitiveaquatic species Water temperature recorded in this study issimilar to those of Lake Mensangat which supports healthyTomistoma population in Kalimantan [18] Bunga-Baki Riverwhich supports a breeding population during this study hasrecorded slightly different WQ compared to the other tworivers (Table 3) It has the lowest pH (average 42) and thelowest DO (average 423mgL) whereas its turbidity recordedthe highest reading (average 44 NTU) thus suggestingthat Tomistoma could tolerate acidic water condition lowDO concentration and moderate turbid water Other WQparameters (Table 4) show that Samarahan River and Bunga-Baki River are in Class I However for Kepayang Riverammonia and orthophosphate concentrations fall into ClassII Thus one may say Tomistoma could live in rivers witha wide range of WQ parameters either Class I or Class IIWQ readings reported in this study are limited to wet seasononly therefore futurework should be carried out during bothdry and wet seasons in order to get a better understanding

of relationships between water quality and the presence ofTomistoma population

34 Current Status of Aquatic Food Resource Compared tothe Gavialis gangeticus [2] suggested Tomistomas have abroader diet including relatively large mammals reptilesand birds as well as small invertebrates In addition [3]reported that plant materials could also be found in stomachof Tomistoma and suggested that Tomistoma ismost likely anopportunistic feeder

During this study the highest CPUE was recorded inKepayang River with the value of 167 kgh followed bySamarahan River (05 kgh) and finally Bunga-Baki River(02 kgh) However compared to [19] results the three riversinvolved in this study have relatively low CPUE valuesReference [19] had recorded mean CPUE for Sblak River(Sibu) Bako-Buntal-SantubongRiver (Kuching) Sibuti River(Miri) and Similajau River (Bintulu) as 114 kgh 201 kgh268 kgh and 242 kgh respectively The authors also notedthat rivers in National Parks where traditional fishing is onlyallowed to local people have relatively higher CPUE values


Table 5 Checklist of fish in Samarahan River Bunga-Baki River and Kepayang River

Family Species Local name RiverSamarahan Bunga-Baki Kepayang

Anabantidae Anabas testudineus Puyu + + +

Channidae Channa striata Haruan minus + +

Cichlidae Oreochromis mossambica Tilapia + + +

Clariidae Clarias batrachus Keli kayu + minus minus

Helostomatidae Helostoma temminckii Biawan + + +

Osphronemidae Trichopodus trichopterus Sepat + + +

Trichopodus pectoralis Sepat Siam + + +

Siluridae Wallago attu Tapah minus minus +

of around 767 kghour CPUE value is one of the approachesto determine status of fish resources in a particular riverbut this does not involve the abundance of other aquaticfood sources thus data presented here should be handledwith caution Checklist of the freshwater fish species caughtat each sampling site is in Table 5 The species caught inthis study are typical of peat swamp fish similar to thosereported by [16 20] In general Kepayang River has largerfish size for example the wallago Wallago attu Majority offish caught during this study have commercial importancethus the rivers are important assets to local communitiesSmall scale fishing can be observed in all three rivers involvedin this study thus one may say fishing activities cause veryminor disturbance to Tomistoma food source Based oninterviews carried out with local people during this studythey put high value on the rivers and very minor changeshappened to the rivers locally for the last 30 years Howeverall respondents agreed that changes are unavoidable in otherrivers connected to their rivers or in the upstream areas forexample conversions of natural forest to big scale oil palmplantation which in turn affect the ecology of the riversOver time wild Tomistoma populations in the rivers willbe affected severely in support of [6] claim that threats toTomistoma came mostly from conversion of peat lands andpandan swamps into agriculture not due to hunting

4 Conclusion

All three rivers involved in this study show presence ofwild population of Tomistoma based on captured individualsas well as recent reports of Tomistoma sightings by thelocal people This study also highlights the presence of abreeding population in Bunga-Baki River thus further workis needed to identify the nesting site for appropriate con-servation actions to be implemented This area is significantfor Tomistoma conservation in Sarawak Future surveys andinterviews are required in other areas in Sarawak to get abetter understanding of the status of Tomistoma in the state

Competing Interests

The authors declare that they have no competing interests

Acknowledgments

Thiswork is supported by theMinistry of EducationMalaysiathrough fundamental Research Grant Scheme FRGSSTWN10(01)10662013 (12) awarded to the first authorThe authorswould like to thank UNIMAS for laboratory facilities andtransportation Thanks are due to Forestry DepartmentSarawak for granting permits to conduct research on bio-logical resources (Permit noNCCD907444 (jld10)-255 andPark Permit no 2632014)

References

[1] M R Bezuijen B Shwedick B K Simpson A Staniewiczand R Stuebing ldquoTomistoma schlegelii The IUCN Red Listof Threatened Species Version 20143rdquo 2014 httpwwwiucnredlistorg

[2] M R Bezuijen G J W Webb P Hartoyo R W S Samediand S C Manolis ldquoThe false gharial (Tomistoma schlegelii)in sumatrardquo in Proceedings of the 14th Working Meeting of theIUCNSSC Crocodile Specialist Group (IUCN rsquo98) pp 31ndash31Gland Switzerland 1998

[3] R B Stuebing M R Bezuijen M Auliya and H K Voris ldquoThecurrent and historic distribution of Tomistoma schlegelii (theFalse Gharial) (Muller 1838) (Crocodylia Reptilia)rdquoTheRafflesBulletin of Zoology vol 54 no 1 pp 181ndash197 2006

[4] J H Cox and F Gombeck ldquoA preliminary survey of thecrocodile resource in sarawak East Malaysiardquo IUCNWWFProject MAL 7485 World Wildlife Fund Malaysia amp theNational Parks and Wildlife Office Forest DepartmentSarawak Malaysia 1985

[5] A C Sebastian ldquoThe Tomistoma schlegelii in Southeast Asia astatus review and priorities for conservationrdquo in Proceedings ofthe 12thWorking Meeting of the Crocodile Specialist Group vol 1of IUCN The World Conservation Union Gland Switzerland1994

[6] R B Steubing S A M Sah E Lading and J Jong ldquoThe statusof Tomistoma schlegelii (Mueller) in Malaysiardquo in Proceedings ofthe 17th Working Meeting of the IUCN-SSC Crocodile SpecialistGroup pp 136ndash140 IUCN Gland Switzerland 2003

[7] A Pine ldquoTomistoma False Gharial Sunda Gavial (Tomistomaschlegelii)rdquo A Report for Mohamed bin Zayed Species Conser-vation Fund Project Number 12255301 2013


[8] R B Steubing E Lading and J Jong ldquoThe status of the falsegharial (Tomistoma schlegelii) in Sarawakrdquo in Proceedings ofthe 14th Working Meeting of the IUCN-SSC Crocodile SpecialistGroup IUCN Gland Switzerland 1998

[9] R Hassan and M I Z A Gani ldquoCrocodiles in Western ofSarawak Malaysiardquo in Proceedings of the 22ndWorking Meetingof the IUCN SSC Crocodile Specialist Group World CrocodileConference pp 90ndash95 Negombo Sri Lanka May 2013

[10] APHA Standard Methods for Examination of Water andWastewater American Public Health Association WashingtonDC USA 2005

[11] J A Gullan Manual of Methods for Fish Stock AssessmentmdashPart 1 Fish Population Analysis vol 1 Food and AgricultureOrganization of the United Nations Rome Italy 1969

[12] R Froese and D Pauly ldquoFishBaserdquo Electronic database 2012httpwwwfishbaseorg

[13] B K Simpson Status Assessment of Tomistoma in PeninsularMalaysia Peat Swamp Forests of Selangor amp Pahang TomistomaTask Force of the IUCNSSC Crocodile Specialist Group 2014

[14] M B Gasim B S Ismail E Toriman S I Mir and T C ChekldquoA physico-chemical assessment of the Bebar River PahangMalaysiardquo Global Journal of Environmental Research vol 1 no1 pp 7ndash11 2007

[15] K Irvine S Vermette and F B Mustafa ldquoThe lsquoBlack Watersrsquo ofMalaysia tracking water quality from the peat swamp forest tothe seardquo Sains Malaysiana vol 42 no 11 pp 1539ndash1548 2013

[16] K A A Rahim S K Daud S S Siraj A Arshad Y Esa andE R Ibrahim ldquoFreshwater fish diversity and composition inBatang Kerang floodplain Balai Ringin Sarawakrdquo PertanikaJournal of Tropical Agricultural Science vol 32 no 1 pp 7ndash162009

[17] AK Sayok S Lau andR Blanda ldquoImpact of land-use onBunutLake Sarawak Malaysiardquo in Proceedings of the 13th World LakeConference Wuhan China November 2009

[18] A Staniewicz Diet and demography of Tomistoma schlegelii inMesangat Lake East Kalimantan Indonesia 2011

[19] J Bali T R Munsang T Ganyai K Bakir and J Jomis CurrentStatus of Aquatic Food Resources in Sarawak Malaysian Bor-neo Oral presentation during Borneo Crocodile Forum 2014mdashHuman-Crocodile Co-existence Roadmap to SustainabilitySibu Sarawak 2014

[20] E M Dosi L Nyanti and J Grinang ldquoThe blackwater fishes ofoil palm plantation in Betong Sarawakrdquo in Proceedings of theRegional Taxonomy and Ecology Conference (TEC rsquo15) 2015

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ClimatologyJournal of


this species in Sarawak Furthermore the authors of [6]had compiled records of Tomistoma in Malaysia based onhistorical information and personal communications withscientists and local people They also highlighted that someTomistomas are currently being held in captivity for ex situconservation purpose in zoos and private farms Sixteenrivers in Sarawak had been claimed as habitats of Tomistoma(1917 to 2003) mostly with small number of Tomistomaindividuals Meanwhile the author of [7] had carried outTomistoma surveys in Engkilili Maludam National Parkand Loagan Bunut and it reported that one individual wasspotted in Engkilili but none in other areas His project haslimited success to verify the population status of Tomistomain Sarawak although the state hasmany potential Tomistomahabitats In terms of conservation priorities for Tomistomawild populations in its geographical range Sarawak is cate-gorized as ldquomoderate priorityrdquo [1]

Threats to Tomistoma came mostly from conversionof peat lands and pandan swamps (black water area withPandanus palms as the common flora) into agriculture [6]not due to hunting because the skin of Tomistoma is of lessvalue commercially and rarely people consume themeat Dueto secretive nature of this species attacks were most probablydue to opportunistic killing rather than aggressive nature ofhunting [8] The species is generally regarded as harmless tohumans although one case of attack on humans has beenconfirmed and others have been reported Similarly localpeople in Sarawak regarded Tomistoma as peaceful animalthat should be left alone but precaution steps are still neededto ensure safety of both humans and animals The species isgenerally regarded as harmless to humans with only smallnumber of reported human-Tomistoma conflicts in Sarawakbut could also cause human fatality for example the one thathappened in Tisak River [8]

People of Sarawak and Malaysia are so proud to be inthe map where Tomistoma is reported to be found yet thisspecies only appeared in folklores told by older generationliving in upper areas of selected rivers This paper describeseffortsmade to locate Tomistomawild populations inwesternpart of Sarawak (2014-2015) which hopefully will lead toTomistoma conservation actions in Sarawak in the nearfuture

2 Materials and Methods

21 Wild Populations Survey

211 Field Visits Paper [8] claimed that Sadong River andother nearby rivers in Simunjan and Ulu Sebuyau Sarawakhave many potential Tomistoma habitats Thus three siteshad been chosen (Figure 1) in Kepayang River (Ulu Sebuyau)tributary of SamarahanRiver and Bunga-Baki River (Serian)For Kepayang River surveys had been conducted in separatevisits that is 22ndndash25th July 2014 4th-5th December 2014and 3rd-4th February 2015 For Samarahan River field visitswere done on 14th and 15th February 2015 and for Bunga-Baki River the visits were done on 21st and 22nd March2015 All visits were carried out at the end of wet season(Northeast Monsoon) except for July 2014 trip for Kepayang

(km)0 100 200 300

Sarawak1

2

3

N

Figure 1 Sampling area in western part of Sarawak 1 SamarahanRiver 2 Bunga-Baki River and 3 Kepayang River

River Due to limited accessibility of all sites surveys werecarried out using boats in the rivers aswell as on foot along theriverbanks Many stretches of the rivers were impossible topass through due to overgrown weeds as well as the presenceof water gates to control water levels in the rivers possibly foragricultural purposes All Tomistoma surveys were carriedout during day time only

212 Study Area

Samarahan River (Samarahan) The Samarahan River is hugeriver with complex river connections with distance of morethan 70 km The downstream is connected directly to theSouth China Sea which experiences the intrusion of salt-water The upstream part (tributary of Samarahan River)comprises peat swamp and small riverine forestThree check-points were selected for water quality (WQ) measurement(Table 1) and Tomistoma surveys were done continuouslybetween checkpoints The selection of checkpoints werebased on natural river landscape observed The tributaryexamined during this survey runs from the main river(Samarahan River) through oil palm estates (about 6 km)followed by 4 km of small peat swamp forestThis tributary isapproximately 12 km long with width of less than 10m Thistributary has very limited access due to overgrownweeds andother floating vegetations Fishing seems to be of low intensitywith some nets and set hooks seen probably belonging toworkers of the plantation There was no boat traffic observedduring the survey No saltwater crocodiles were seen in thistributary although SamarahanRiver recorded a good numberof human-crocodile conflicts [9] which resulted in bothinjuries and fatality

Bunga-Baki River (Serian) The river is located near twovillages namely Bunga Village and Baki Village The river isrelatively small in the upstream area with approximately 2 to3m width in contrast to the wider size in the downstreamarea (4 to 5m) The Bunga River flows from the mountaininto Baki River and later to Sadong River The Bunga Riverflows through a forested landscape which has fairly clearwater and comprises many rocky streams The area is shadedwith the forest trees thus the air temperature is relatively




Samarahan River

1 N 1∘25101584017410158401015840E 110∘32101584016010158401015840

N 1∘25101584001510158401015840E 110∘32101584038210158401015840 857m 0

2 N 1∘25101584001510158401015840E 110∘32101584016010158401015840

N 1∘24101584038510158401015840E 110∘34101584010910158401015840 293 km 0

3 N 1∘24101584038510158401015840E 110∘34101584010910158401015840

N 1∘23101584050310158401015840E 110∘3710158400210158401015840 543 km 0


E 110∘29101584053110158401015840N 1∘13101584025710158401015840E 110∘30101584036510158401015840 202 km 0

2 N 1∘13101584037310158401015840E 110∘30101584031810158401015840

N 1∘4101584050710158401015840E 110∘31101584029910158401015840 282 km 0

Kepayang River

1 N 1∘23101584001310158401015840E 110∘55101584013510158401015840

N 1∘22101584050710158401015840E 110∘55101584037910158401015840 129 km 0

2 N 1∘24101584010610158401015840E 110∘53101584026010158401015840

N 1∘23101584058810158401015840E 110∘53101584059810158401015840 101 km 0

3 N 1∘21101584027210158401015840E 110∘55101584038410158401015840

N 1∘20101584035410158401015840E 110∘55101584040610158401015840 525m 0

4 N 1∘19101584019410158401015840E 110∘56101584022010158401015840

N 1∘19101584019310158401015840E 110∘56101584031910158401015840 300m 0




























33 Water Quality








Bunga-BakiRiver




1232015Captured (119899 = 1)


04m Local people

Kepayang River








(mgL NH3ndashN)




4


SiO2)


















4 Conclusion


Competing Interests


Acknowledgments


References


























Journal of












Volume 2014

Advances in









Geophysics

















Samarahan River

1 N 1∘25101584017410158401015840E 110∘32101584016010158401015840

N 1∘25101584001510158401015840E 110∘32101584038210158401015840 857m 0

2 N 1∘25101584001510158401015840E 110∘32101584016010158401015840

N 1∘24101584038510158401015840E 110∘34101584010910158401015840 293 km 0

3 N 1∘24101584038510158401015840E 110∘34101584010910158401015840

N 1∘23101584050310158401015840E 110∘3710158400210158401015840 543 km 0


E 110∘29101584053110158401015840N 1∘13101584025710158401015840E 110∘30101584036510158401015840 202 km 0

2 N 1∘13101584037310158401015840E 110∘30101584031810158401015840

N 1∘4101584050710158401015840E 110∘31101584029910158401015840 282 km 0

Kepayang River

1 N 1∘23101584001310158401015840E 110∘55101584013510158401015840

N 1∘22101584050710158401015840E 110∘55101584037910158401015840 129 km 0

2 N 1∘24101584010610158401015840E 110∘53101584026010158401015840

N 1∘23101584058810158401015840E 110∘53101584059810158401015840 101 km 0

3 N 1∘21101584027210158401015840E 110∘55101584038410158401015840

N 1∘20101584035410158401015840E 110∘55101584040610158401015840 525m 0

4 N 1∘19101584019410158401015840E 110∘56101584022010158401015840

N 1∘19101584019310158401015840E 110∘56101584031910158401015840 300m 0




























33 Water Quality








Bunga-BakiRiver




1232015Captured (119899 = 1)


04m Local people

Kepayang River








(mgL NH3ndashN)




4


SiO2)


















4 Conclusion


Competing Interests


Acknowledgments


References


























Journal of












Volume 2014

Advances in









Geophysics






























33 Water Quality








Bunga-BakiRiver




1232015Captured (119899 = 1)


04m Local people

Kepayang River








(mgL NH3ndashN)




4


SiO2)


















4 Conclusion


Competing Interests


Acknowledgments


References


























Journal of












Volume 2014

Advances in









Geophysics




















Bunga-BakiRiver




1232015Captured (119899 = 1)


04m Local people

Kepayang River








(mgL NH3ndashN)




4


SiO2)


















4 Conclusion


Competing Interests


Acknowledgments


References


























Journal of












Volume 2014

Advances in









Geophysics


























4 Conclusion


Competing Interests


Acknowledgments


References


























Journal of












Volume 2014

Advances in









Geophysics
































Journal of












Volume 2014

Advances in









Geophysics














research article notes on the wild tomistoma populations...

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