Hdi nghi Khoa hgc vd Cdng nghi biin todn qudc lan thir F
THANH PHAN, M A T DO VA SV" PHAN BO CUA ©ONG VAT PHU DU VUNG D A M THI NAI, TINH BINH DINH
Nguyen Cho, Truffng ST Hai Trinh, Nguyen Thi Thanh Thuy Vien Hai duang hpc, 01 Cdu Da, Nha Trang
Email: [email protected] Tom tdt:
Ket qud hai chuyin khdo sdt ddng vgt phit du (DVPD) vdo miia mira (11/
2008) vd miia khd (4/2009) dd xdc dinh dirge 124 lodi DVPD, trong do nhdm chdn mdi cheo (copepoda) chiim ini the v&i 68 lodi (55%), rdii ngdnh (cladocera) chiem 15 %. Tdng sS lugng lodi trong dam (HI lodi) cao gap 3.4 Idn sd lug'ng lodi & sdng (33 lodi). Mat do tning binh DVPD todn darn dgt 19.358 cd thi/m^ vd & cdc trgm trong ddm (23.656 cd thi/m^) cao gdp 22 idn so v&i cdc trgm trong sdng (1.091 cd the/m^). Mat do tning binh nhdm chdn mdi cheo dgt 17.820 cd thi/m^, chiem 92,1 % tdng mat do DVPD trong viing. Vdo miia khd, mat do tnmg binh DVPD (34.459 cd thi/m^) cao gdp 8 Idn so v&i miia mira. Chi sd tirang ddng vi thdnh phdn lodi (Bray - Curtis) cho thdy sir phdn nhdm ro ret ve thdnh phdn loal giira cdc trgm trong ddm vd khu virc cdc sdng do vdo dam. DVPD & cdc trgm trong sdng cd chi sd cdn bdng Pielou (J) vd chi sd da dgng Shannon (H') cao han so v&i cdc trgm trong dam trong khi do chi sd gidu cd lodi (Magalef'd) & cdc trgm trong ddm (4.3) cao gdp 2 Idn so v&i cdc trgm trong sdng (2,4).
THE COMPOSITION, DENSITIES AND DISTRIBUTION OF ZOOPLANKTON IN THI NAI LAGOON, BINH DINH PROVINCE
The results of two surveys during the rainy season (11/2008) and dry season (4/2009) identified 124 species of zooplankton, in which copepoda were most diverse with 68 species (55 %), followed by cladocera (15%).
The total number of species in the lagoon (111 spp) was 3.4 times compared to that in the rivers (33 spp). The density of zooplankton was relatively high with an average of I9358.5inds/m . The average density of zooplankton in the lagoon (23,656 inds/m^) was 22 times compared to that (1,091 inds/m^) in the rivers. Copepoda was abundant, with an average density of 17,820 inds/m , corresponding to 92.1% of the total zooplankton. The average density of zooplankton in the dry season (34,459 inds/m^) was 8 times (4,257 inds/m ) compared to that in the rainy season. On the basis of the Bray-Curtis similarity index, there were two distinct groups those in the lagoon and in the rivers. In the rivers the species evenness (Pielou J') and
Tiiu ban Sinh hgc vd ngudn lgi sinh vgt Bien
the diversity index (Shannon H') were both significantly higher than those in the lagoon while the species richness (Margalef s d) in the lagoon (4.3) was 2 times compared to that in the rivers (2.4).
1. MO DAU
Ddm Thi Nai thupc hai huyen Tuy Phudc vd Phu Cat, thanh phd Quy Nhon, tinh Binh Djnh, la ddm Idn thii 2 teong sd cdc ddm pha d Viet Nam. Tong dien tich mgt nude Iiic trilu len ciia ddm 5.060 ba, teong do dipn tich nuoi tdm viing dam tinh din nam 2008 khoang 1.393,7 ha chilm 65 % tong dien tich nuoi tom ciia tinh, gidi qiiylt cong an viec Idm, gop phdn cdi thipn dang ke ddi song vgt chat, tinh thdn ciia cpng dong dan cu ven ddm. Tuy nhien, tinh den nam 2010, chua co mdt nghien ciiu ve tong the vl nguin lgi tdi nguyen sinh vat cua ddm, ddc bift la nguin lgi sinh vdt pbii du - ca sd thiic an cho nuoi tring thiiy sdn (NTTS). Ddng vdt phu du (DVPD) la mat xich quan trpng teong chudi thiic an ciia thiiy vuc, la nen tdng chu ylu de danh gia mirc do phong phii, ciing nhu su d nhilm cua moi tmdng. Sinh vdt lugng DVPD tang hay gidm deu dnh hudng true tiip hay gidn tiip den nguon lgi nghe ca ciing nhu nganh NTTS. Do vay, ddnh gia hien trgng DVPD la mpt teong nhiing npi dung quan trpng cua nhiem vu "Nghiin ciru ca s& khoa hgc nhdm xdy dimg cdc gidi phdp phdt triin nudi trong thuy sdn bin virng tgi dam Thi Ngi, tinh Binh Dinh" do Vi?n Hdi duang hpc chu tri, thgc hipn trong giai doan 2008-2010.
II. TAI LlEU VA FHirONG PHAP NGHIEN CUtJ
Mau DVPD dugc thu thdp tgi 21 team mat rpng vdo thdng 11-2008 va thdng 4-2009 tgi ddm Thj Ngi, tinh Binh Djnh (Hinh 1).
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Hinh 1: Sadd vi tri trgm thu mdu dgng vdt phii du tgi ddm Thi Ngi
Hgi nghj Khoa hoc va Cong nghe biin toan quoc lan thiiV
Tai cac tram mat rong, mlu DVPD dugc thu bang luoi hinh chop, co duong kinh mi?ng ludi 37 cm may bing vai ludi nylon, co duong kinh lo ludi 200 fim. Mau dugc thu bang each keo thing diing bang tay each nen day 0,5 met d§n tSng mat. Mau vat dugc c6 djnh bSng dung dich formol 5%, sau do dem ve ^han tich cr phong thi nghi?m. Sinh vat lugng DVPD duge xac dinh bing each dim mlu den loai dudi kinh hiln vi soi noi, va dugc bieu thi bSng s6 lugng ca thi tren mgt don vi the tich (ca thS/m').
Cac chi s6 sinh thai dugc tinh bing phSn m6m Primer (Primer - E Ltd, Plymouth UK)
nhu sau: , , . . .
- Do giau CO loai (Margalef): d = (S-l)/Log (N), S: tong so loai, N: tong so ca the ciia tram/mau.
- Chi s6 can b5ng Pielou: J' = HV Log(S)
Chi s6 da dang Shanon: H' = - sum (Pi*Log2 (Pi)).
- So sanh thanh phin loai bing chi s6 tugng dong Bray Curtis.
D6 xac dinh gidng loai DVPD, cae tai li?u tham khao bao gdm: Cheng va Zhang (1965); Cheng va Zhang (1974); Owre va Foyo (1967); Nishida (1985a,b); Boltovsky (1999); Mulyadi (2004); Dang Nggc Thanh va cs (1980); NguySn Van Khoi (1995).
m . KET QUA NGHIEN CUU IILl. Thanh phan lo^i
Kit qua phan tich 42 mau DVPD thu dugc vao thang 11/2008 va 04/2009 da xac djnh dugc 124 loai (Bang 1), trong do chan mai cheo (copepoda) co 68 loai (55 % tong so loai) chilm uu thi so vdi cac loai khac. So loai g cac tram trong dam (111 loai) cao hon 3,4 lan so vdi cac tram trong song (33 loai).
Bdng 1. Thdnh phdn vd ty le phdn trdm cdc nhom dgng vgt phii du tgi ddm Thi Ngi vdo miia mua (11/2008) va miia kho (4/2009)
Nhom loai Bai nghieng (Amphipoda) Ham to (Chaetognatha) Rau nganh (Cladocera) Chan mai cheo (Copepoda) Ctenophora
Tom sen (Cumacea)
Chan canh va Chan khac (Pteropoda & Heteropoda) Quan thuy mau (Hydromedusae)
Chan deu (Isopoda) Tom quy (Lucifer, Sergestidae) Thiy mau ong (Siphonophora) Co vo (Ostracoda) Giun nhieu ta (Polychaeta) Co bao (Tunicata) Tong so
Tdng so loai
1 4 19 68 2 1 4 6 1 2 4 2 I 9 124
Phin tram(%)
0,8 3,2 15,3 54,8 1,6 0,8 3,2 4,8 0,8 1,6 3,2 1,6 0,8 7,3 100
Thang 11/2008 Dam
4 7 51
2 1 1 4
7 77
Song 1 15 8
1
25 Thang 4/2009 Dam
1 3 53 2 1 2 6 1 1 2 3 7 82
Song
6 9
1
16
Tiiu ban Sinh hgc vd nguon lgi sinh vdt Biin
Ket qua cho thay khu vuc dieu tra co thanh phan loai tuong doi phong phu bao gim cac nhom lodi nude man, nude Ig (Lucifer hanseni thuoc nhom torn quy, Sergestidae) va cdc nhom logi nude nggt (Pseudodiaptomus incisus, Pseudodiaptomus annandalei thupc nhom chan mai cheo). Nhu vay viing dinh ddin trong thai gian khdo sat chiu dnh hudng ciia khoi nuoc ngpt tir luc dia dd ra. Cac loai chiem uu the d day chii yeu Id cac loai chdn mdi cheo CO kich thudc nho thupc cac giong nhu: Paracalaniis, Oithona, Acartia ...., cdc Ioai biin khaiphan bl rpng co kich thudc Idn thudc cac gidng nhu: Subeucalaniis, Tortaniis.... chi chilm mpt sl lugng nhd va chi xuat hien d cac trgm giiia va cua ddm.
IIL2. Sinh vat lugng dpng vat phii du
Mat dp trun^ binh cua DVPD thu dugc tai 21 trgm mat rpng d viing dilu tra khd cao, dat 19.358,5 the/m^ (Bang 2), trgm co mat dp cao nhdt dat 72,797 cd tbl/m^ (trgm 9) va thap nhdt dat 275 ca thl/m^ (Trgm C, Hinh 2).
Miia kho (thang 4/2009) co mgt dp dgt 34.459 cd the/m"', cao gdp 8 Idn so vdi mua mua voi mat dp dat 4.257 cd thl/m^ (thang 11/2008) (Hinh 2). Mat dp DVPD hung binh (23.656 cd the/m^) cua cdc trgm trong dam (team 1-17) cao gap 22 lan so vdi mat dp trung binh (1.091 ca the/m^) (p <0,05) ciia cdc tram trong song (trgm A, B, C, D).
Bdng 2. Mat dg tning binh (cd the/m ) ciia dgng vgt phii du vimg ddm Thi Ngi
Nhom Boi nghieng (Amphipoda) Ham to (Chaetognatha) Rau nganh (Cladocera) Chan mai cheo (Copepoda) Tom sen (Cumacea)
ChSn canh & Chan khac (Heteropoda
& Pteropoda) Chan deu (Isopoda) Au trung Cd vo (Ostracoda) Giun nhieu to (Polychaeta) Tom quy (Lucifer.Sergestidae) Co bao (Tunicata)
Tong so
Trung binh (ca the/m^)
26 146 158 17 1 81 1 978
1 1 70 104 19.358,5
%
0,1 0,8 0,8 92,1
0 0,4
0 5,1
0 0 0,4 0,5 100
Hoi nghi Khoa hgc va Cong nghe biin loan quoc lan thii V
1 6 0 0 0 0 - MOOOO _ 120000
^ 100000 O 80000
40000 20000
^
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NA j i i n ]
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J i n .
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• ^ 1 2 3 4 5 8 7 B 9 10 11 12 13 14 IS 16 17 A B C O Tram
mmust IK (I1J200B} l==IM«t Ob (04;2009) -a-S& kn/no toii (11.'3008) - O - S i lirvng loM (OV2009}
Hinh 2. Biin ddi mat dg dgng vdt phii du tgi cdc trgm khdo sdt khu vuc dam Thi Ngi IIL3. Cac chi so sinh thai
Phan tich chi sd tuong ddng (Simalirity index) cho thdy co su phan nhom rd ret giua cac trgm trong ddm vd cac trgm d luu vuc cac song (Trgm A, B, C, D). Chi so tuong dong giiia 2 nhom trgm teen chi dat gan 5% (Hinh 3).
Cdc tegm trong ddm cung cd su phan nhdm ro ret giiia cac tram d dinh dam (70 %), giiia ddm (70 %) vd ciia ddm (80 %). Dua teen chi sd gidu cd lodi d Bdng 3 vdi phep thir Z-test cho hai luu vuc (ddm vd song) cho thay gid tri chi so giau cd lodi d (Magalef) d cdc trgm trong dam (4,3) cao gan gap 2 lan so vdi cac tegm d luu vuc sdng (team A, B, C vd D) (2,4) vdi gid tn P <0,05).
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Hinh 3. Bieu do phdn tich nhdm cdc nhdm trgm khdo sdt ddm Thi Ngi Phdn tich so lipu trung binh theo tram cho ket qua cdc thdng sl chi thi muc dp da dgng lodi dugc bieu thi d Hinh 4. CJ cac trgm trong sdng (A - D) va cdc trgm d phdn dinh ddm (trgm 1 - 5) cd so lugng lodi dao dpng 11-21 lodi, thap ban so vdi cae tegm con lgi d giCa va ctra ddm (tegm 6 - 17) vdi so lugng loai dao dpng 26 - 60 loai. Hinh 4 ciing chi cho thdy chi so da dang Shaimon cung co xu the tuong tu, cao nhdt d tram 16 va trgm A, teong d6 trgm A cd chi so cdn bdng Pielou (J') cao bon. Cdc team 2 va 15 cd chi sl biin thien sl
Tiiu ban Sinh hgc vd nguon lgi sinh vdt Bien
lugng loai cao ban chi so da dang la do mat dp dpng vat phu du chi tap trung vdo mpt s6 Ioai vi vdy co chi so da dang lodi thdp.
9 10 11 12 13 14 15 16 17 A B C D
—Chi s6 aa dang Shanon (H") - O - C h I &6 cSn bSng Pietou (J')
Hmh 4. Bien thien sd lugng lodi (S). chi sd cdn bdng Pielou (J) vd chi sd da dgng Shanon (H) theo trgm cua ddng vdt phit du ddm Thi Ngi
IV. NHAN XET
Da xdc dinh dugc 124 loai DVPD, trong do nhom chan mai cheo (copepoda) chilm uu the vai 68 loai (55%), rau ngdnh (cladocera) chiem 15 % vd co bao (tunicata) chilm 7%.
Tong sl lugng lodi trong ddm Thi Ngi (111 loai) cao gap 3,4 lan sl lugng loai d song (33 lodi). So lugng Ioai ndy kha Idn so vdi nhiing ket qud nghien ciru trudc day ve DVPD (212 lodi) va chdn mdi cheo (127 loai) d vimg biin Viet Nam (Nguyen Van Khoi va cs, 1991).
S\r da dang lodi d day co su ddng gop phan Idn ciia cac Ioai trong dam Thj Nai, no tieu biiu cho khu he DVPD ven bd Nam Trung Hoa (Shirota, 1966).
Mat dp teung binh DVPD todn ddm Thi Nai khd cao, dat 19.358,5 ca the/m^ Mat dp trung binh DVPD d cac trgm teong ddm (23.656 cd the/m"') cao gdp 22 lan so vdi cdc tram hong song (1.091 cd the/m^). Ket qua nay cao ban so vdi cdc ket qua khao sat trudc day d vjnh Phan Thilt thang 5/1999 (2.278 ca thl/m^), kit qua khdo sdt d viing biin ven bd KhanhHoa 7/2001 (13.192 cd thl/m^) vd dim Cii Mong thdng 10/1999 (17.004 ca thl/m^) (Nguyin Cho, 2001; 2002). Mdt dp trung binh nhom chan mai cheo dat 17.820 cd thl/m^
chilm 92,1 % ting mat dp dpng vdt phii du trong vimg. Vdo miia kho (4/2009), mat dp trung binh DVPD dat 34.459 ca thl/m^ cao gdp 8 Idn so vdi mua mua (11/2008).
Chi so tuong ding vl thanh phdn lodi (Bray - Curtis) cho thdy sir phdn nhom ro ret ve thanh phan lodi giiia cac trgm trong ddm va khu vuc cdc song do vao dam. Dpng vdt pbii du d cac tram trong song co chi sd can bang Pielou (J') vd chi so da dang Sharmon (H') cao hon so vdi cac trgm trong dam trong khi do chi sl giau co loai (Magalef) d cdc tram trong dam (4,3) cao gdn gap 2 Idn so vdi cdc tram trong song (trgm A, B, C va D) (2,4).
Hgi nghj Khoa hgc vd Cong nghe biin todn quoc idn thic 1/
LOI CAM ON
Nhom tac gia xin chan thanh cam on Ban KH va CN dia phugng, Vy KH-TC, Van phong Bo - Bg KH & CN, Sd KH va CN Binh Dinh; Sg NN va PTNT Binh Binh, Vien KT va QH TS, Vi?n Nghien cuu NTTS3; cac eg quan va cgng ddng dia phugng da giiip dd va tag di^u kien thuan lgi cho nhdm nghien ciiu trong suot thdi gian thuc hi?n nhiem vu.
TAI LI$U THAM KHAO
1. Boltovskoy, D. 1999. South Atlantic Zooplankton. 1999, Volume. 2.1. Blackhuys Publisher, Leiden, The Netherlands.
2. Chen, Q.-C. and Zhang, S.-Z. 1965. The planktonic Copepods of the Yellow sea and East China sea. 1. Calanoida. Studia Marina Sinica, 1965, No. 7, pp. 20-123.
3. Chen, Q.-C, Zhang, S.-Z. and Zhu, C.-S. 1974. The planktonic Copepods of the Yellow Sea and East China Sea. IL Cyclopoida and Harpaticoida. Studia Marina Sinica,1974, 9:75-115.
4. Dang Nggc Thanh, Thai Tran Bai va Pham Van Mien, 1980. Dinh Ioai dgng vat khong xuong sdng nude nggt Bac Viet Nam. 1980, Nha xuat ban Klioa hgc va ky Thuat.
5. N^iyen Cho, 2001. Ddng vat phii du vinh Phan Thiet. Tap chi Khoa hpc va Cdng nghe bien,T.1.2001, Trang. 18-24
6. Nguyen Cho, 2002. Dgng v$t phu du viing bien ven bd tinh Khanh Hoa. Tuyen tap Nghien ciiu bi6n, 2002, XIIL 151-164.
7. Nguyen Van Khoi, Nguyen Cho, Nguyen Tien Canh va NguySn Tan Hoa. 1991. Dgng vat phii du viuig bien Viet Nam. Tuyen tap nghien ciiu bien. Tap III, Nha xu3t ban Khoa hgc va Ky thuat, 1991, trang 99-111.
8. Nguyen Van Khoi, 1995. Chan mai cheo (Copepods) vinh BJc Bg. Nha xudt ban Khoa hgc va Ky thuat, 1995, 200 trang.
9. Nishida, S. 1985a. Taxonomy and distribution of the family Githonidae (Copepoda, Cyclopoid) in the Pacific and Indian oceans. Bull. Ocean Res. Inst., Univ Tokyo 1985, No. 20.
10. Nishida, S. 1985b. Pelagic copepods in Kabira Bay, Ishigaki Island, southwestern Japan, with the description of a new species of the genus Pseudodiaptomus. Pubis Seto Mar. biol. Lab. 1985, 30: 125-144.
11. Owre, H. B. and Foyo, M. 1967. Copepods of the Florida current. Fauna Caribaea. No I. Crustacea, part 1, Copepoda, 1967, p. 1-135.
12. Shirota, A. 1966. The plankton of South Vietnam - Fresh water and Marine plankton.
Colombo Plan Expert on Planktology Saigon University and the Oceanographic Institute Of Nhatrang Vietnam. Overseas Technical Cooperation Agency, Japan 1966 462pp.
