t~p va cong ngh~ bi~n
TRANSCRIPT
T~p chi Khoa hQc va Cong ngh~ bi~n T7 (2007). S6 3. Tr 44 -54
TONG QUAN v:E TiNH HiNH NGHIEN coo cA. voi o viJNG BIEN VI~T NAM
v A MOT v AI BitN PHAP DE nAo vt CHUNG
44
PHAM THUQC
Tom tat: Dei c6 m¢t viii cong trlnh nghien dru ve' ca voi J wing bie'n VietNam vii vtlng
bie'n cac nu6'c Dong Nam Chdu A(Perrin.1994; Smith et al. 1995). Gruvel (1925) fd'n dd'u lien
dd ghi nhr?n ca voi xanh (Balaenoptera physalus)c6 J wing bie'n Vi¢t Nam . Cho de/1 nam 1995
chua c6 m¢t cong trinh chinh tlu:rc niio nghien dru sdu vl ca voi J VLing bie'n Vi¢t Nam.(Smith
eta!. 1995). M¢t viii ldn da g{ip Bo Bie'n(Dugong) J vt.lng bie'n Nam Vi¢t Nam(Trein Ng9c L<;!i.I962 vii Van Bree and Duguy, 1997).
V GO tlzang 3 vii thang 4 nam 1995, fd'n ddu tien nglzien dru vrJ' CG voi dtWC t/nt'c hi en J vtlng bie'n mie'n Trung va Nam VietNam. d ddng bang song Ciilt Long va ddo Plul Quoc(Vinh
Thai Lan). D<;!t nghien dru nay dci m6 td 17 loai ca voi. ThOng 10 niim 1999 va thiwg 4 nam
2000. cong lac nghien Clt'u ttlCfl7g w dtl<;fC tiel? hanh J vfnh Bac B¢ va van thea phuong phap
quan sat Ia chinh va 10 loai dii ghi nhdn dtf<;fC.
Hai d<;!t nghien ct.!'u tren du'<;fc tht;tc hi¢n bdi To' cht:rc Bdo ton thien nhien Quae te'
(1UCN)do nh6m chuyen gia ve' ca voi vel qu_y Bdo ton Cong viert biei1(0cean Park Conservation Foundation) ct.lng v6'i cac c!tuyen gia Vi¢t Nam etta cac vien nghien dru khac
nhau ddm nhiem vel dii phat hi¢n them 6 loeli. Nhu vdy J vtlng bie'n Vi¢t Nam dci phat hien
duoc 25 ioiii ca voi.
Qua CGC d<;!t nghien Clf'U vel tharrt kftao teli fi eu /ich sf( drJ'u nhdn dinh lei CG VO i klzong CO
gia tri kinh tl liJn J wing bie/1 Vier Nam nlurng c6 y nghia ra't quan tr9ng ve' mat tam lin!t rMi
viJi ngu· dan J Vi¢t Narn. dac biet Ia J vtlng biel·z grin bb mie'n Trung va Narn Vi¢t Nam. Ca voi
dtf(J'C ton kinh VG thiJ CLtng.
Hcln g nam . ca voi dtf<!c tho· cting trong nhii'ng ngcly hoi. Ngtr dan g9i ca voi Ia "Ong"
thay vi ca voi ten thuilng g(Ji. Tmye'n tlwyet eta glti nlu(ln rdng . ca 6ng voi del dru v6't ngu dan ding n/n( b<;111 be Clla c/n/ng qua n/i£i:ng CO'il gfong to' phii p/K)ng. bang each SIJ' dung CO' th lf' dlf'
diJ cac tdu . tlwye'n ho(lc ddng d¢i bi kier SlfC ngorli Dai dtfO'ng. N gu ddn dii xdy dt,L'ng mie!t
mgo. cte'n tho· ca voi ell the' hi¢n long ton kinh va biet O'n sdu sac. Ngoeli /(/con c6 r(/t nhie'u
cac m!/u chuyen khac ve' su· thong rnin!t Cit a ca ong voi ( dac bi¢t /c) ca heo thu¢c b¢ phu ca voi
c6 rang) va mol quan he ro't d~p ella ca voi n6i chung va ca !teo n6i rieng viJi con ngl(iJi .
0 mie'n Tmn g vrl Nam Vi¢t Nam. c6 nhie'u de'n tho· ca 6ng voi. tgi d6 luu giii· cac b¢
Xtt'O'ng ca voi vel cdc d¢ng vat khac nhtr Dugong va ca heo. D6 Ia nlu111g 1'/IGU vat rd't c6 gia tri
cho c6ng tcic nghien c{ru klwa hoc.
Cci voi xanh lei loeli ca thu rinh trong ding nhtt' baa loeli tlui khac soltg tren C((l/1. Ca cai
c6 c/11'ra ki?'o diii 11 thang tlu' sinh con . Vtla tach khoi rnr; c6 voi con l(lp tti'c no'i len k!tdi mat
nubc. Trang nlning ngay con tho' dgi, ca con luon luon cgp ke ben m£!. Ltic d6i, ca con cu¢n
cong cai luiJi nhu the' cai o'ng de' nggm !c(y vu nlf!, thai gian b1.i si?a nlf! keo dai tbi 7 thang. Ca
voi con phdi sau 6-7 nam mbi bubc vao tu6i trttd'ng thanh va tham gia vao thai ky sinh sdn
ddu tien. Ca voi xanh phdn b6' clui ye'u d' cac v1lng bie'n on dbi. Den m1la dong gia lgnh. chung
di ell den cac vLing mrbc phia Nam de' kiein an. Khi nula xudn ve' cluing lgi di ell ngw;c lgi.
Bie'n Dong ciing Ia Mi dinh duiJng nia nluiu loai ca voi kh6ng rang. M¢t vai loai trong
khi kieln an; nlu7ng con da chef do rru:ic vao /ubi ho(ic do m¢1 nguyen nluin nao d6 bi chef va
froi dar vao bo. Nhdn ddn ta a CllC wing ven bie'n eta mai tang rdt chu cldo va lgp cdc de'n tho,
mieil mgo nhll tho CIJng m¢t vi Thdn Bie'n. chinh vl truye'n thuyet da ke' rang cd voi tii:ng da dru
nguai cluing may g(ip ngn tntbc song gi6 c1ia Dgi duong.
I. MO DAU
Vi~c nghien cull d¢ng v~t c6 vu 6 bien duqc nhiell co qllan t<;ti nhiell nu6'c thJ!c hi~n:
VNIRO, TINRO, PINRO, AzcherNIRO va cac vi~n thll¢c Vi¢n han lam Khoa h<;>c Lien
Xo (cil) nhu: Vi¢n sinh h<;>c phat tri~n. Vi~n sinh thai va hlnh thai tien hoa d(>ng v~t. Vi~n
d<?ng v~t. Ngoai ra, NMt, Nauy, Ha Lan va Anh cilng da thanh l~p cac vi~n chuyen nghien
CUu ve ca voi - ca heo. 6 My, Canada, Uc, NillZilan, Nam Phi ... cilng c6 CC1 qllan nghien
CUll ca voi - ca heo.
Tu tru6'c t6'i nay c6 rat it cong trlnh nghien CUll ve d¢ng v~t c6 vu 6 vung bien Dong
Duong. Tlly nhien c6 hai cong trlnh nghien CUll chu yell 6 vung bien nay la: Nghien ctiu ca
heo (Orcaella brevirostris) 6 song Mekong thu¢c cam Pu Chia, Lao, Vi¢t Nam (Lloze 1973,
Baird et al. 1994 ). Chua c6 c6ng trlnh nao nghien CUll trJ!c tiep voi quy mo 16n ve ngu6n
lqi ca heo d<;>c bo bi~n Vi¢t Nam. Ngoai ra chi c6 3 loai ca voi da duqc bao cao d6 la: C3
voi xanh (Balaenoptera musculus) (Grllvel, 1925), ca ong chllong (Kogia breviceps
Serene, 1934) va ca heo (Tursiops truncatus) (Zholl anh Qian, 1985). Ca ong su
(Neophocaena phocaenoides) tuong doi n6i tieng 6 Vi¢t Nam. Tren CC1 so nhiing buc anh
cua h¢p SQ da duqc xuat biin boi Kremf (1993). Ngoai ra loai ca cui (Dugong dugon
Miiller, 1776) doi khi cilng quan sat thay 6 vung bi~n Vi¢t Nam (Tran Ng<;>c Lqi, 1962;
Van Bree va Duguy, 1977).
Tu thang 3-4 nam 1995 m¢t nh6m chllyen gia Vi~t Nam va nu6'c ngoai g6m 7 nguoi
da thl;{C hi~n m(>t Chllyen nghien CUU nham thll th~p tai li~ll ve d(>ng V~t bien dQC bO bien
Vi~t Nam. Theo ket qua thong bao thl nh6m chuyen gia nay da t6 chuc tham do 95 gio, da
xac dinh rat nhieu loai tu mftu xuang ca voi, 16 loai thll¢c b¢ ca voi (Trong d6 c6 ca ca
heo) song 6 bi~n Vi~t Nam.
Thang 10 nam 1999 va thang 4 nam 2000, cong tac nghien cuu tuang w duqc tien
hanh 6 vinh Bac b¢ va 10 loai da ghi nMn duqc.
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Ca voi, ca heo la cac loai ca quy hiem 6 m(>t so nu6c tren The gi6i, ngu6n lqi nay da
c6 nguy ca c~n ki~t. Vl v~y, van de nghien cu ca sa sinh v~t hQC, tlnh hlnh ngu6n lqi,
nham biio v¢ tai t~o cac loai ca voi, ca heo 6 vung bi~n VietNam la nhiem vu buc xuc cua . . . chung ta hi¢n nay cling nhu trong tuang lai .
II. D~C DIEM CHUNG B(> cA VOl (CETACEA)
Ca voi than hlnh rat 16n, c6 thf dai t6i 20m, n~ng 14 tan. Ben than c6 hai go da cao
ch~y dQc tu khe mang t6i b~p duoi, m~t khong c6 mfmg, rang rat nho, mQc thanh dai r(>ng
tren ham, c6 t6i 15.000 cai. Luqc mang dai mfmh va mQC rat day tren cung mang d~ lQC
thuc an. Da mau xam ho~c xam hong c6 nhieu van va vet mau trang ho~c vang.
Ca voi va ca heo Ia nhfrng d(>ng v~t c6 vu 6 bi~n. Trong D~i duang The giai hi¢n c6 3 b(> d(>ng v~t c6 vu 6 bi~n g6m han 100 loai. Chung c6 miftt 6 tat ca cac vung sinh thai cua
D<;1i duang: Bifn khai v6i d(> sau Ian va vung gan bo v6i d(> sau nho han. Doi v6i nhfrng
d(>ng v~t nay moi truong cac vung nhi¢t dai cling nhu nhfrng vung gan qrc d~u phu hqp.
C6 loai song 6 tang nn6c mat, c6 loai c6 th~ song 6 d(> sau lOOOm. Da so song 6 bi~n, chi
c6 m(>t soft song 6 nn6c ngQt.
B(> nay bao g6m nhu·ng d(>ng v~t c6 vu da chuyen hoa cao, khong con lien h¢ v6i dat
lien va thfch nghi v6i loi song dn6i nu·6c. Than c6 hlnh thuy loi . Trong qua trlnh thfch
nghi, Cclc phan nh6 ra cua C0 th~ da bj thmii boa nbU" mau tai ngoai, VU cua con cai nam
trong nbfrng cai tui d~c biet, con C0 quan sinh dl;!C cua con ctu·c thl nam trong kboang than .
Cac chi tru6c bien thanh vay ep sat vao than, cac chi sau thoai boa toan b(>. Ca quan
chuy~n ct(>ng chfnh la vay ctuoi 2 tl1Uy v6i he C0 rat khoe.
Hinhl. Ho~t dc)ng ctla duoi ca voi
46
Da so cac loai tren lung c6 1 vay lung khong XUO'ng. Dau l&n, dai c6 khi t<:tO thanh
m(>t cai m6 phfa tru6'c . Khong c6 ducmg phan bi~t c6, dau chuyen ngay sang mlnh va thu
dan v~ phia duoi . Long bao phil ho~m to~m khong c6. 0 ca voi tren dau va ham du6'i chi giil'
l<:ti vai SQ'i long v6'i chtrc nang XUC giac. 0 ca heo nhfi'ng SQ'i long nhU the chi CO a giai do<:tn
bao thai. Lop rna duoi da phat trien m(;lnh thl!c hi¢n chuc nang each nhi¢t.
PMn lOn cac xucmg c6 cau t;:to xop chua nhi~u rna, cung voi lOp rna duoi da lam cho ty trQng co th~ cua ca giln v6i ty trQng nu6c . .
Khong c6 moi m~m, lucri kha phat tri~n, d<:t day phuc t<:tp g6m 3 - 5 pMn (C6 khi den
12- 13 phan). Chi~u dai ruc;>t gap tu 5-6 den 15- 16lan chi~u dai than.
Hai lo mui (v6'i ca voi) ho~c 1 lo mui (v6'i ca heo) nam o tren dau. Lo mfii c6 cac van
dung de dong l<:ti khi ca l~n. Khi quan va phe quan ng~n . Ph6i 1 thuy c6 h¢ co rat khoe. D¢ng tac tho (tho ra - hit vao) rat ngtm. Khi th6 ra tu du6i m~t nu6c t;:to thanh c¢t nu6c,
d~c bi¢t thay r6 6 nhil'ng vung nu6c l;:tnh.
Nao b9 phan hoa cao song van c6 vai d~c diem nguyen thuy. Khoi luqng nao rat 16n,
nhung so v6'i khoi luqng CO' the thll<:ti la khong dang ke. Mat khong l&n, comat phat trien
tot, mf mat khong phat tri~n, cac tuyen I~ thoai hoi Co quan khuu giac thoai hoa, thay vao
d6 la co quan vt giac hlnh thanh o lucri. Lo tai nam sau m~t va khong lOn. Ca voi c6 kha
nang tiep nh~n am thanh trong khoang tu 150HZ den 120- 140 nghln HZ. Oxy trong mau
nhi~u han 6 d¢ng v~t c6 vu tren qn nhi~u liln. Nhi¢t d¢ ca the dao d¢ng ttr 35 - 40"C. Ca
quan di~u nhi¢t la da va c6 le nhat lab~ m~t cac vay. Cac chi tru6c da mat chuc nang v~n
d¢ng nen CCJ phat trien yeu, trong luc d6 CCJ cua vay duoi va CCJ mlnh dam nMn chuc nang
v~n d¢ng nen kha phat trien.
Tinh hoan nam a khoang bl,mg, CO' quan giao cau nam a khoang than, sinh con trong
nuoc. Ca con bu sil'a m~ du6i nu6c va moi lan bu chi keo dai vai giay. Sfra c6 ham luqng
rna lOn ( 40 - 50%) va an bum in, vl v~y ca con phat tri~n nhanh trong giai do;:tn bu sfra m~.
Ca voi la nhfrng d¢ng v~t song thanh dan .. Phan 16'n c6 the di cu theo mua, c6 mc;>t so
loai di cu n1t xa. Thucmg chi de 1 con.
1. Be) ph~ Ca voi khong rang (Mystacoceti)
G6m nhfrng d;:ti di~n c6 kich thuoc 16n nhat cua b¢ ca voi .
- Da so c6 than dai, hlnh thuy loi, mc;>t so it than ng~n.
- Dilu lOn, chiem 1/3 - 1/5 chi~u dai than.
- C6 va mlnh li~n nhau.
- SQ doi xtrng, phan tru6c nho ra. Vom mfii r¢ng. Ham du6i dai va nho v~ 2 ben.
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- Da so ca voi khong rang bai nhanh, di cu. Thai gian mang thai tu 10 - 11 thang.
Thong thuang chi de 1 con, rat it khi 2 con va v6 cung han hfru - vai con. Thai gian bu mt;: keo dai 6-7 thang.
- Thea d?c diem dinh du5ng nguai ta chia ca voi khong rang thanh 3 nh6m:
+ Nh6m an zooplankton kich thuoc nh6.
+ Nh6m an zooplankton kich thu6'c trung blnh va ca con.
+ Nh6m an nhfrng d<?ng v~t giln day.
- Ca Voi kh6ng rang phan bo kh~p cac D~i duang va bien khai tu vung qrc cho den cac vung nu6'c nhi¢t d6'i .
- Ca cai thuang to han ca dy:c.
2. BQ ph~;~ Ca voi co rang (Odontoceti)
La b9 ph1,1 bao gom nhfrng d<?ng v~t v6'i kich thu6'c khac nhau trong d6 c6 h9 ca heo (Delphinidae). D?c diem phan bi¢t la c6 rang (tl.r 1 den 250 rang ho?c han) .
- Xuang SQ n1t kh6ng doi xu·ng. 0 giai doan bao thai xuang SQ c6 nhfrng d~c diem rat
giong XUO'ng SQ cua d9ng V~t CO VU tren c~n , 6 nhfrng giai do~n phat trien ve sau thl kh6ng con sy: giong nhau do d6 m9t so xu·ang dfnh vao nhau.
- M9t diem quan trQng cua b9 ph~,I nay la Stf tach bi¢t gifra tht,rc quan va duang h6 hap.
- Lu6'i cua b9 phy c6 rang nay la m9t khoi CO' duqc phil bang nhieu lop bieu bl sung va mo lien ket. Thy:c quan cilng v~y.
- D~ day nhieu ngan .
- Chi c6 1 lo mili.
- Phfa tren SQ c6 vai tui khf c6 chu·c nang dong duang h6 hap l<;li khi ca l~n sau du6'i nu6'c .Ngoai ra cac tui hai nay con t<;10 ra tieng keu cua ca.
- Ca quan thfnh giac va cac than kinh thfnh giac phat tri~n tot.
- Con dy:c thuang to han con cai.
-Da so cac loai thu<?c b9 phy ca voi c6 rang, song 6 bien khai, nhung cilng c6 nhi:i'ng
loai song 6 vung gan ba. Chung deu la nhilng d<?ng v~t bai rat gi6i va b~t nhli'ng con moi di d<?ng nhanh nhu ca, mt,fc ...
III. MOT s6 THU(>c TfNH v A D~c DIEM SINH HOC
Ca voi la loai ca n6i D<;li duang, thuang di thea dan bai l¢i cMm ch~p, doi khi di le
vao vung bien giln ba kiem an ho~c bt song d~y d~t vao ba. Trang nhu·ng truang hqp d6 thuang bi danh bk Oic d~m ca heo thuang g~p tl.r 3 - 4 con , c6 con n~ng hang tram kg.
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Mua ca n6i tu thang 4 - 8 ca heo di theo cac d~m ca trfch, ca ngu, ca song, ca earn de bil:t
m6i. Khu Vl;(C t~p trung nhat la vung dao B~ch Long Vi (v!nh B~c b¢ ), a vung bi~n khai mien Trung cling nhu Vfing Tau da thay ca voi va ca heo. Yay duoi rna ca voi bai theo hlnh dao d¢ng song theo m~t phffmg dung.
Ca voi c6 kieu bai l~n ng1;1p r6i ngoi len m~t nu6'c de c6 th~ tho duqc de dang Oxy trong khong khf.
Ca voi, ca nha tang deu c6 kha nang l~n lau. KM nang l~n lau toi da cua ca voi bi~n la 12 phut, ca voi thuemg- 30 phut, ca voi xanh- 49 phut, ca nha tang- 120 phut.
Ca voi cuu b~n bang each bai xum l~i. nang b~n len m~t nu6'c d~ b~n de tho. T~p tinh nay c6 le la do Sl;{ ket hqp v6'i t~p tinh b~m sinh cua ca voi m~ khi sinh con. Ca voi SO' sinh thubng duqc ca voi m~ va cac ca voi c6 m~t a day bai den va nang len m~t nu6'c d~ chu ca voi m6'i de tho duqc hai tho diiu tien.
Sinh de: Ca voi thl;l tinh trong nhung de trt!ng, miiu b~t duqc trong thang 5 c6 bu6ng
tnrng n~ng 0,5 kg, c6 khming 4200 trung non, duemg kfnh trung 1,4 - 1 ,6mm. Trung duqc
b<;>c trong VO sung 16'n, bao thai nam cu¢n ben trong.
Ca voi c6 each to tlnh rat d~c bi¢t,vao thai gian phat tri~n (Chin mu6i tuyen sinh dl;!C) no khong thich bO'i ke ben nhau, lay vay d~p nUOC vao nhau, rna con CO th~ nhay V<;>t len tren m~t nu6'c r6i l~i nhao xuong m¢t each d~c sac.
Dinh duemg cua ca voi, ca heo:
Tu lau nguoi ta da nh~n thay rang nang luqng tieu hao doi v6'i moi kg khoi luqng
tren CO' the nho se cao han so v6'i CO' the 16'n. Tren CO' sa d6 neu nhu chung ta thul~p m¢t
being so sanh yeu du ve thuc an a nhil'ng loai ca voi (thu c6 co l6'n nhat trong gi6'i sinh v~t
c6 khoi luqng tir cao den thap) th~ hi~n nhu sau:
Bang 1. Luqng thuc an trung binh dn cho m¢t ngay dem
(Tfnh theo phan tram so v6'i khoi Iuqng cO' th~) c--·- - ----·-- - - ··- ---- - - --
Khoi luQllg co th~ Khoi lttQllg thuc an trung blnh
trong 1 ngay dem (%) Ten loai ca Voi (Tinh bang
Trong truO'ng hqp Trong truO'ng kilogram)
blnh thuO'ng hqp tich rna Ca voi xanh 96.810 2,0 4,3
Ca voi thuang 59.000 2,6 6,2
Ca voi buu 34.810 3,6 7,2
Ca voi xam 31.550 3,9 7,8 - -·- -- t----- - --
Delphin tr~ng 1.100 7,4 11,4 '---·
(Ngu6n: Tran Kien, 1978)
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Qua bang tren thay r6 rang yeu cau ve so luqng thti'c an tang dan tu ca voi c6 kh6i
luqng co th~ ·Ian den ca voi c6 khoi luqng co th~ nh6 va yeu cau so luqng thuc an trong
thai ky tfch rna 16'n han trong truang hqp blnh thuang.
Thanh phan thU:c an la d¢ng v~t n6i va ca nh6 duqc gilt l~i sau qua trlnh li;lc db'~g nu6c tu mi~ng qua mang.
IV. GIA TR~ KINH TE
Ca voila loai ca l6n nhat trong so ca hi~n song, la loai duy nhat trong·giong va h9 ca
nham voi. Chung song trong cac D~i duang nhung thu¢c lo;:ti ca hi en nen la m¢t doi· tuQ'ng san Mt cua ngM ca bi~n, nha't la khi vao gftn bo, la hi~n v~t ha'p diln trong cac bao tartg(:·~ "
Nguoi ta da che bien dftu ca voi tu m6', tu thit va tu ru¢t ca. Dau ca c6 th~ dung d~ hrt ho~c dung trong ky ngh~ lam xa phong. Vitamin A ciing duqc chiet tu g<'m ca voi;-'thtt ca
voi c6 th~ dong h¢p lam thl,l'c ph~m. Xuong ca voi duqc nghien t hanh b¢t dung lam·thtl'c ari
gia sue hay phan b6n. Chat keo che tu xuong ca voi con duqc dung trong ky ngh~: lam
phim anh. Ca voi la m¢t nguon lqi kinh te dang k~ vl the tren The gi6i ngu.oi ta da xay
di!Jlg-nhiing h;:tm d¢i san ca voi va bien nhieu chiec tau tr6 thanh nhiing nha may "i16i" treh
mat bi~n.
Cling can nhan m;:tnh ding trong b¢ ca voi thl ca heo la lo~i ca kha thong minh.
Nhieu "tai nang" cua ca heo da lam cho con nguoi rat ham m ¢: Ca heo c6 th{ l~m "hoa
tieu" dan tau bi~n, bi~u dien nhfrng pha xiec nhao l¢n va th~ d~;~c th~ thao rat ky th ~, ca h~q biet ve nhiing bU:c tranh mau s~c, ca heo da lam cho nhiing quy khach du l[ch , "ng l\"5;).1g
m¢" thoai mai sau nhfrng chuyen di dai ngay cua mlnh .. ..
Ky ngh~ ca voi vao nhfrng nam sau chien tranh The gi6i Ian . thU: II da phat tri~n rat
m;:tnh me.Vl the hi~p u6c Quae te quy dinh vi~c san b~t ca voi , Lien I;i~p quae eta c6 nghi
quyet cam khai thac cac lo~i ca nay.
v. THA.O LU~N, DE XUAT PHVONG HVONG NGIUEN .CUlJ,
v A nA.o vt NGUON LQI.
Trong 30 loai ca voi da xac cttnh ctu·qc 6 vung Dong Nam chau A; khu vt,rc An D¢ Ma
Lai (Perrin 1994, 1995) thl c6 16loai da xac dtnh duqc 6 Vi~t Nam, cho den nay da len t6i
khoang 25 loai.
Cac ngu dan da thong bao dng, doi khi h9 ciing danh duqc ca heo bang· lu6il re. Ca
heo la lo<;ti d¢ng v~t tho bang khong khf thuong bt chet rat nhanh sau khi danh duqc bang ltr6'i re. Thl!c .ra 6 Vi~t Nam chua c6 chU:ng c6 Cl,l th~ la ngu dan trt,rc tiep di tim ca voi, ca
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heo d~ khai thac. Vf nhu nghe khai thac ca nho a m(>t so nuac Chau A Philippines (Dolar
et al. 1994 ), Sri Lanka (Leatherwood and Reeves, 1989) va Indonesia (Barnes, 1991)
(Trich d~n tu Brian D .. Smith ,1995).
Tuy nhien bao lao d(>ng ngay 27/6/1993 da cong bo 1 con ca voi n~ng 300 kg vai
chieu dai 4,2 m dab! bat va dua vao ba ban vai gia 200.000d/ kg thit.
Cilng can nhan m~nh la ngu dan Viet Nam a cac dia phuong khong bao gio coi
nguon lqi Ca VOi n6i Chung va Ca heo n6i rieng la IDt}C tieu dU'a l~i nguon lqi song chfnh
cho mlnh. Vllo~i d<';>ng v~t nay doi khi con cuu cac lo<;ti t<lu ho~c ngll'oi bi tai n<;tn tren bi~n.
Ngu dan tuy lam vi~c tren bi~n m~t nhQC, nhung van thfch quan sat nhung d~m ca
heo khi chung nhao l<')n bO'i dQC thea ttlu thuyen danh ca.
Bao lao d¢ng ngay 16/3/1995 thong bao c6 1 con ca heo rat to da duqc g<;ip abo bi~n. ngu dan da tlr choi kh6ng ban th!t rna con mai tang a m¢t th6n c6 den tho ca voi thea
tt}c 1~ dia phuang. Da so ngu· dan Vi~t Nam muon tho cling ca voi, bai hQ tin rang lo(;li
d(>ng v~t nay se cuu dO' hQ khi g~p dnh hi~m nguy tren bi~n.
Phuong huang nghien cuu va bao v~ nguon lqi:
-Xay dl,fng 1 dl,f an nghien cuu toan di~n a vung bi~n Vi~t Nam ve moi truong anh
huang den doi song cua ca voi, ca heo. Xac dinh chi tiet CO' sa sinh v~t hQC, t~p tfnh, phan
bo va tlnh hlnh nguon lqi lo~i ca nay. Kinh phi cho cong tac nghien cuu do Nha nu6'c cap
va hqp tac nghien cuu vai nuac ngoai.
-Tang cuong cong tac ki~m tra, ki~m soat, nghiem cam vi~c chu d¢ng khai thac lo<;ti
ca nay. Trang truong hqp cac lo<;ti ca tren b! vuang vao luai ho~c d<;tt vao bo m9i nguoi c6
trach nhi~m tlm mQi bi~n phap cuu song va tha l~i bi~n.
-Tuyen truyen sau r(>ng trong nhan dan hi~u sau sac y nghia quan tr9ng cua lo<;ti ca
voi, c6 trach nhi~m ki~m tra giam sat va phat hi~n nhung hanh vi sai trai d~ bao v~ lo<;ti ca
quy hiem nay.
Tren day la nhil'ng so li~u bu6'c dau xem xet ve ca voi, ca heo a vung bi~n Vi~t Nam,
la m(>t vai dan li~u nft SO' b(> CO th~ gop phtln rat nho d~ tham kbao, dinh hu6'ng cho c6ng
tac nghien cuu trong tuO'ng lai .
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Bang 2. Thanh phan cac loai trong b<? ca voi (Cetacea) 6 bi~n Vi¢t Nam --- ·
TT Ten khoa hoc Ten VietNam --- r-- ---- -
Suborder: Odontoceti B(> ph1,1 ca voi c6 rang -
Family: D~_Iphin~~~_Gray, 1821 H9 ca heo/ca he
1 Sousa chinensis(Osbeck) Ca heo /ca heTrung Quoc
2 Stene/la longirostris(Gray, 1828) Ca heo/ca he Ma Lai
3 Stenella cocruleoalba(Mayen, 1833) Ca heo/ca he B~c B9
4 Delphinus tropicalis Van Bree, 1971 Ca heo/ca he chfnh thtl'c
5 N eophocaena phocaenoides(Cuvier, 1829) Ca ong str
6 _I_ursj_ops truncatus(~_~mtagu, 1821) -- -7 Orcaella brevirostris(Owen, 1866) Ca ntrqc Minh Hai
8 Pseudorca crassidens(Owen, 1846)
9 Grampus griseus(Cuvier ,1812) Ca heo /ca he Risso ----- ·-- -10 Stens breda ne nsis(Lesson, 1828) Ca heo I ca he rapg nhap
Family Physet eridae H<;> ca voi khong rang
11 Kogia breviceps(Blainville, 1838 ) c_a on_g chL~.!.!_g
12 Physeter macrocephalus(Linnaeus, 1758) Ca nha tang
Suborder: Mystacoceti B(l ph1,1 ca voi khong rang
Family: Balaenopteridae Ho ca voi khon<r ranu -- __ , ___ ______ , "'
13 Balaenoptera acutorostrata Lacepede, 1804 Ca ong mom
14 Balaenoptera boreali~ Lesson, _!_~28 Ca onu bite -- - - l:> -
15 Balaenoptera edeni Anderson, 1878 Ca ong brai
16 Balaenoptera plzys9lus(Linnaeus , 1758) Ca ong xam - -
17 B. musculus Linnaeus , 1758 Ca voi lam . --
18 Megaptera noveangliae _ _ ______ _______ _ Ca voi lu·ng_g~---------------·----.. Suborder:Pinnipedia ------- ------·---- - -Family: Otariidae --- ------ ------ --- ------
19 Callorhimts ursinus Linnaeus, 1758 Str ti:r b~ -- . --- ------ - ------·--20 Eumetopias jubatus(Sc~t::-~t::r , 1776) Bao b~
- - f-·- - -----
r---- - _family_:_!'_!l~_<:!~~e_!Jr()~_ard 1~_~5 --- - --·- -------------21 Plioca vitulina Linnaeus, 1758 cho be _________ .. ___________ ____ ----·-·-·----·----- ------------
Suborder: Sirenia -- --- - -- r---
Family: Dugongidae Gray 1821 ·------- r----·- --22 Dugong dugon(Miiler, 1776) ca Cui ----·-·--·------ - --
(Ngu6n : Dao Van Tien , 1994)
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TAl LI~U THAM KHAO
1. Arssenhev, 1973; Morskie mlekopitaiushe
2. Agarkov, 1974; Morfologia Delphinov
3. Brian D. Smith, 1995; Marine Mammals of Vietnam: A preliminary checklists
4. Brian D. Smith,1999; Notes on the Status of Cetaceans in the Gulf of Tonkin
5. Tran Kien, 1978; Doi song cac loai thu- NXB KHKT 1978
6. Ph~m Thuqc, Le Van Dung, 1995; Hi¢n tri;lng cua cac loai ca voi tl;li Vi¢t Nam va
m(lt vai bi¢n phap bao v¢ chung
7. Dao Van Tien, 1994; Thanh phan cac loai ca voi va ca heo c6 6 bi~n Vi¢t Nam
OVERVIEW OF WHALE RESEARCH IN VIETNAM AND SOME PROTECTION SOLUTIONS
PHAM THUOC
Summary: There were some researches on whale in Vietnam and Southeast Asia
seawaters (Perrin 1994. Smith et a! , 1995 ). Fin whale (Balaenoptera physalus) was firstly
recognized in Vietnam by Gruvel (1925) . There was no specific study focusing on whale in
Vietnam seawaters (Smith et aL 1995). Dugong was recorded some times in Vietnam (Tran Ngoc Loi , 1962; Van Bree and Duguy, 1997).
In March - April 1995, the first study on whale was carried out in the Central and Southern Vietnam, in Mekong Delta and Phu Quoc Island (Gulf of Thailand). In this study, 17
whale species were described. Another similar study was made in the Gulf of Tonkin in
October 1999 and April 2000 and still using the observation method, in this study 10 whale
species were identified.
The two series of studies mentioned above were carried out by IUCN experts in whale and Ocean Park Conservation Foundation and Vietnamese experts from some institutions, and
6 more whale species were recorded. In all, 25 species of Cetaceans are recognized in the
Vietnamese seawaters.
Based on studies and historical references , it is considered that whales have no great
economic value but have a great spiritual significance for the fisherfolk in Vietnam, especially
in the Central and Southern Vietnam. Whales are respected and worshiped.
Whales are worshiped in annually festival days. Fishermen call whales "Ca Ong Voi"
(Vietnamese) or Mister Ong. Legend said that Ca Ong Voi saves fisherman and its friends from storms and tempests using its body to prop boats/vessels or fellow-creatures in distress at sea. Fisherfolk have built temples to worship Ca Ong Voi so as to express their great gratitude and respect. In addition, there are some stories of the intelligence of Ca Ong Voi (especially
dolphin species of the toothed whales (suborder Odontoceti)) and the good relationship
between whale in general and dolphin in particular with man.
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The Central and Southern Vietnam have many Ca Ong Voi temples keeping skeletons of whale and other mammals like Dugong and dolphin, which are very valuable to research activities.
Fin whale is a fish species of internal fecundation like various terrestrial mammal
species. The female remain pregnant for 11 months before giving birth. Right after being born,
the calf instinctively swims to the surface. In the first days, the newborn always stay closely
with the mother. The calf is nurtured with its mother's milk and is weaned in 7 months . Calves reach sexual maturity in 6-7 years. Fin whale distribute mainly in temperate seawaters. In the winter, they migrate toward the south, into warmer waters to feed , and in the spring they migrate back.
The South China Sea (Eastern Sea) is also a feeding area of various toothless whales .
When feeding, some whale individuals died due to hanging up against fishing net or certain
reasons, and were washed onto the shore. The people living at the coastal villages buried dead
whales kindly and built temples to worship them as the Sea Deity, because legend said that
whale (Ca Ong Voi) rescued persons in distress from waves and storms in the ocean.
Ngity nh~n biti: 25 - 7 - 2007 JJja chi: Trung tam Tu van Chuy~n giao Cong ngh~ Nguon lqi thuy sinh va Moi truong (Acttare)
Ngtti!i nh~n xet: PGS,TSKH. Le TrQng Phfrn
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