Observations on the Dugong, Dugong Dugon (Muller), in the Andaman and Nicobar Islands, India

4 Pages·1999·2.1 MB·

by  H S Das

OBSERVATIONS ONTHEDUGONG,DUGONGDUGON(MULLER),
IN THE ANDAMAN AND NICOBAR ISLANDS, INDIA
1
H. S. Das2 and S. C. Dey3
(With two text-figures)
Key words: Dugong dugon Andaman and Nicobar Islands, habitat protection.
,
The paper presents records ofdugongs in the Andaman and Nicobar Islands. Morphological
description ofan adult female caughtdead in a fishingnetnearHut Bay in the Little Andamans
isalsogiven. Itisconcludedthatthepopulationofdugongintheislands,thoughnotveryhigh,is
significant and can be conserved by protecting itspotential feeding grounds.
Introduction inmostoftheremainingareas.InIndia,dugongs
occurintheGulfofKutch,GulfofMannar, Palk
Situated between 6-14° N and 92-94° E, Bay and Andaman and Nicobar Islands.
the Andaman and Nicobar Islands have large Seagrasses being the staple food, the dugong is
areas of seagrass, rich in diversity, which intimately associated with the seagrass habitat.
flourishes in clear, low-turbidity coastal waters. Information on dugongs in the Indian
At least nine species of seagrasses belonging subcontinent is available for Gulf of Mannar,
to six genera grow here (Das 1996). Fishes, PalkBay andGulfofKutch. However, there are
turtles, crustaceans andechinodermsmainlyuse not many records such as photographs or
this habitat. Seagrass beds are also crucial for morphometric descriptions of dead or live
the highly endangered marine mammal, the dugong from the Andaman and Nicobar coast.
dugong. A photograph ofa dead dugong from Diglipur
Intherecentpast, theurgentneedto study area was published by Rao (1990) and a
theseagrasshabitatanditsassociatedanimallife diapositive of a dugong caught dead near Hut
in Andaman and Nicobar Islands was felt by BayduringMarch 1989isavailableatZoological
several workers (Silas and Fernando 1985, Rao Survey ofIndia (ZSI), Port Blair (P. T. Rajan,
1990). Accordingly, a study was initiatedbythe pers. comm.). Besides, there are a few other
Salim Ali Centre for Ornithology and Natural reports(BhaskarandRao 1992,Rao 1990,James
History (SACON) to evaluate the habitat status, 1988, Jones 1980) which mention the presence
resourcepotentialandconservationvalueofthis ofdugongs in the Bay Island.
ecosystem. The primary objective of the study
wastoidentifythepotentialseagrasshabitatsfor Methods
conservation, and information on dugong was
also collected during the study. The survey was undertaken, with the help
Once widely distributed, the dugong oflocal fishermen and divers, from morning to
Dugong dugon (Muller) has disappeared from evening around the seagrass habitats of the
manypartsofitsrealmandisunderseriousthreat selectedlocalities(Figs.1 and2)during 1994and
1995 (pre- andpostmonsoonperiods). The sites
AcceptedJanuary,1998. were sampled randomly by snorkelling and
'SalimAliCentreforOrnithologyandNaturalHistory, diving, since there is no established method to
P.O.Anaikatty,Coimbatore641 108. estimate dugong population size accurately in
DirectorateofFisheries,PortBlair,
Andaman&NicobarIslands,India. the wild, except by aerial survey. Interview
JOURNAL, BOMBAYNATURAL HISTORYSOCIETY, 96(2), AUG. 1999 195
THEDUGONGINTHEANDAMANANDNICOBARISLANDS
N
0
CarNicobar
NorthAndaman
Diglipur
D Ttii1llanchangDwip
Q
MiddleAndaman
Tarasa
Dwip n CCaammoirta
VA
TTrri"nket
Cb
Katchall
&($J*Ritchie's
Island
Archipelago Nancowrygroupof
Havelock Islands
*3
SouthAndaman GreatNicobar
Islands
RutlandIsland
t
50km
Little Fig. 2: Map showing survey locations in the Nicobar
Andaman
HutBay Islands
50km ResultsandDiscussion
Fig. 1: Map showing survey locations in the Surveys by motor boat and rowing boat
Andaman Islands around Ritchie’s Archipelago, North Reef,
Marine National Park, Wandoor, and Diglipur
surveys were conducted to collect data on during 1994 and 1997, and Little Andaman,
encountersandsightingsofdugonginthecoastal Camorta, Pilo Milo, Little Nicobar and Great
villages close to the survey area. As dugong Nicobar Islands during 1995 and 1997 failed to
poaching is illegal, the local fishermen were locatedugongsinthewild. Onseveraloccasions,
reluctant to share information. Hence, the bones could be examined at Maya Bunder, Port
interviews were done informally in several Blair, Havelock, HutBay,KatchallandCamorta.
coastalvillagescoveringvarioustribes,racesand Theinformationgatheredthroughinterviewswas
communities of the Andaman and Nicobar Is. very useful. Most of the tribes, namely the
The measurement ofmorphological features of Andamanese,OngesandNicobaresetraditionally
a dead specimenatHutBaywas doneby one of hunt dugong with iron harpoons tied to a boat
the authors (Dey). Subsequently, we examined (dunghi). Shompens have no knowledge of
the complete skeleton. dugong hunting, hostile tribes (Sentinelese and
196 JOURNAL, BOMBAYNATURAL HISTORYSOCIETY, 96(2) AUG. 1999
THEDUGONGINTHEANDAMANANDNICOBARISLANDS
Jarawas) were not interviewed. Settlers, though Moreover,aroundRitchie’sArchipelago,agroup
theyhave no knowledge abouthunting, attimes offive or six dugongs were seen by fishermen
getdugonginfishingnetsclosetoseagrassbeds. and divers on at least five separate occasions
Noneofthetribesgo forregulardugonghunting during 1990-1997 and six near Landfall island
because ofthe time and effort it takes to catch on regular basis. Thus, the number ofdugongs
one. The settlers fromthe mainland ofIndia are living around the island groups are estimated to
mostlyHindus(BengaliandHindispeaking)and bearound40(Table 1).However,adetailedstudy,
do not like dugong meat as it looks and tas.tes preferably an aerial survey along the coast with
like beef. Though there are no religious taboos expert help is essential to ascertain reliably the
preventing them from eating dugong meat, the population size.
settlers prefer fish. Hence killing is very often On February 19, 1997, a dugong was
unintentional. To avoid legal problems, if an caughtandbroughtdeadtotheshoreatHutBay,
m
animal iscaughtdeadinthe fishingnet, settlers/ Little Andamans. Since the net was laid 500
non tribals hand it over to the tribes who are offshore near the 11 km stop at 1700 h on
exempted from the Wildlife (Protection) Act, February 18, 1997 and the animal was noticed
1972. dead in the netnext morning at 0430 h, it must
Table1 havegotentangledanddiedanytimeduringthat
INTERVIEWSURVEYSONDUGONGSIGHTING period. Probably, the dugong had come to feed,
BYFISHERMENANDDIVERSDURING1990-1995.
as evidenced by the presence of surrounding
Localities People/ Numberof seagrasspatches andthe stomachcontentsofthe
Tribes Dugongs animal. When it was brought ashore, the Asst.
reported
FisheriesDevelopmentOfficer(co-authorofthis
Andamans
paper) was informed. He reached the site
Landfall Settlers 6
Diglipur Settlers * immediately and prevented the fishermen from
NorthReefIs. Nohabitation * distributing the meat and bones. The dugong,
Ritchie’sArchipelago Nohabitation 6 anadultfemale (length: 2.63 mandweight: 250
LDiuttgloenAgndCraemeakn OSentgtleesrs 55! kg), was buried under sand after recording
StraitIs. Andamanese * morphometric details (Table 2). The complete
skeleton was exhumed later and kept in the
Nicobar
Katchall Nicobarese 5 fisheries office at Hut Bay. The skeleton was
Camorta Nicobarese 10 examined in detail in May 1997.
LittleNicobar Nicobarese 4 Dugongs were common in the 1950s, but
GreatNicobar Nicobarese 4
the population has dropped drastically in the
Shompens
recent past, as evidenced by sporadic sightings
* sporadicsightingsreported,butnumbersnotconfirmed. andrarerecordsofpoaching. Theprimaryreason
! AsthedistancebetweenHutBay(LittleAndamans)and for this decrease in this island group is habitat
Dugongcreekisonly18km inthesea,itispresumedthat loss, which has resulted from increasing heavy
thesamepopulationoffiveanimalscoverboththeareas.
boat traffic, faulty land use practices such as
The fishermen and regular divers had conversion of forests to banana, areca nut and
sightings offive dugongs on separate occasions coconut plantations. Natural calamities like
between 1990and 1994,alongthenorth-western cyclones and high energy tidal storms may also
side of Camorta Island, five sightings near be partly responsible. In fact, a wounded and
Dugong Creek and Hut Bay (five individuals), dead dugong was noticed by Andaman Public
and four specimens each around Little Nicobar WorksDepartmentworkersnearPilo Kunjiofthe
(Pilo Milo side) and Great Nicobar Islands. GreatNicobarIslandsinJuly 1989afteracyclone.
JOURNAL, BOMBAYNATURAL HISTORYSOCIETY, 96(2), AUG. 1999 197
THEDUGONGINTHEANDAMANANDNICOBARISLANDS
Table2 collected,weproposethatthefollowingmeasures
MORPHOMETRICDETAILSOFTHEDUGONG
CAUGHTDEADINAFISHINGNET should be taken for the conservation of du-
ONFEB. 191997ATHUTBAY gongs in the Andaman and Nicobar Islands:
(1) initiation of environment education
Dateoffishing 19.ii.1997(Fishingnetwaslaidat5pm programmesinthecoastalvillages,(2)protection
on 18.ii.97andtheanimal wasfound ofpotential dugong habitats and enforcing strict
dead in the net on 19.ii.97 morning,
freshbody) legislationtoprotectdugongsinandaroundthen-
Sex Female(lactating) feeding habitats by restricting human activities
Totallength 2.63m such as fishing and trafficking, and (3) regular
Weight 250kg monitoring ofthe dugongpopulation. The study
Perimeteratchest 1.8m
Flippersize 42cmx53cm also advocates the necessity ofan aerial survey
Snouttodipper 55cm of dugong populations to determine its current
Snouttoeye 33cm status, and to undertake long term monitoring
Heightofthe
thereafter.
bodyonground 63cm
Stomachcontent semi-digestedseagrassspecies.
Acknowledgements
Thisstudyconcludesthatdugongsareless
abundant than in the recentpast. Althoughtheir The paper is part ofthe project “Status of
numbers are highly reduced and large the seagrass habitats of the Andaman and
populationsare seennomore, dugongsstillexist Nicobar Islands” sponsored by the Ministry of
at least around Ritchie’s Archipelago, North Environment and Forests, Govt, ofIndia. Help
Reef, Little Andamans, Camorta (Allimpong, renderedby theForestdepartment and Fisheries
Trinket and Pilpilow), Little Nicobar and parts DepartmentoftheAndamanandNicobarIslands
ofthe Great Nicobar Is. On the basis ofthe data during the survey is gratefully acknowledged.
Refer iNCES
Bhaskar, S & G.C. Rao (1992): Present status ofsome Dugongdugon(Muller)oftheIndo-SriLankanWater-
endangered animals in Nicobar Islands.J. Andaman problemsofresearchandconservation.Spol. Zeylan.
Sci.Assoc. 8(2): 181-186. (Colombo Museum centenary volume) 35 (J&2):
Das, H S. (1996): Status of seagrass habitats of the 223-260.
AndamanandNicobarcoast.SACONTechnicalReport Sila—s,E.G.&A.B.Fernando(1985):TheDugonginIndia
No.4.pp32. Is it going the way ofthe Dodo? Proc. Symp.
Jam^s,D. B. (1988): Someobservationsandremarkson Endangered Marine Animal and Marine Parks,
the endangered marine animals of Andaman and Cochin, 1985, 1: 167-176.
Nicobar Islands. Proc. Symp. Endangered Marine Rao,GC.(1990): Presentstatusoftheseacow,Dugong
AnimalandMarineParks, Cochin, 1985(1):337-340. dugon(Muller)inBayIslands.J.AndamanSci.Assoc.
Jones, S. (1980): Thedugongorthesocalled mermaid. 6(2): 181-186.
198 JOURNAL BOMBAYNATURAL HISTORYSOCIETY, 96(2) AUG. 1999