Tiiu ban Sinh hoc vd ngudn lgi sinh vdt Biin
DONG VAT THAN M E M DAM DE GI
H u a Thai Tuyen Vien Hdi Duong Hpc 01 - Cdu Dd, Nha Trang, Viet Nam
Email: [email protected] Tom tdt:
Kit qud khdo sdt 15 trgm mat rgng vdo 2 d0 thdng 10/2009 vd 4/2010 da xdc dinh dugc 56 taxon thdn mim. Cdc trgm gdn cira sdng cd thdnh phdn loal nhiiu han khu vuc con lgi Mdt sd lodi trong chiing cd gid tri kinh ti nhu Meretrix lyrata, Meretrix liisoria, Anomalocardia spp., Batillaria zonalis....Mdt do thdn mem dgt 13.543 cd the/m', miia khd cao han miia mira.
Cdc trgm a cira sdng cd mgt dg thdn mim cao han khu vuc cdn lgi.
MOLLUSCA FAUNA IN DEGI LAGOON (BINH DINH PROVINCE) Abstract:
56 ta.Ka be longing to23fainiHes,2 classc (Gastropoda and Bivalvia) of Phylum Mollusca had been identified through the survey conducted at Degi lagoon (Binh Dinh province) in Oct 2009 and April 2010. Some of them have commercial value as Meretrix lyrata, Meretrix liisorla, Anomalocardia spp., Batillaria zonalis ... Composition species at nearby estuary is higher than other station. The mean density of molluscs reached 13,543 inds./m^. Densities of Molluscs in dry season were higher than winner season. Density of molluscs at nearby estuary is higher than other areas.
L MOf DAU
Dam De Gi la mpt thiiy vyc dugc chi phdi bdi luu vuc sdng La Tinh vd tuong tdc vdi vimg bien ven bd thdng qua mpt cira h?p. Trong dam tdn tai nhieu he sinh thai nhu day mem, rirng '• nggp mdn. co bien vdi nhieu ngudn lgi thuy bd! san quan trpng gdp phan phat trien kinh te xa hgi va duy tri ddi sdng cua mpt bp phdn dan cu ven dam. Bai bao nay la mpt phan trong ndi dung nghien ciru da dang ddng vdt day trong dam nham cung cap nhiing dii lieu mdi nhdt ve hi?n trang ddng vgt thdn mem lam co sd cho nhung nghien ciiu hep theo.
H. TAI LIEU VA PHU'ONG P H A P
- Phuang phdp thu mdu: Mdu dpng vdt than mem dugc thu bang Idiung cd kich thudc 33 X 33cm vdi su ho trp cua thilt bi lan SCUBA. Mau dugc lpc qua ludi cd kich thudc mdt ludi 0,5 x 0,5mm. Thu todn bp sinh vdt va cd djnh trong dung djch cdn 70%.
Moi tram thu 3 mau. Tdng sd mau thu thap gdm 48 mdu d 16 tram vao thang 10/ 2009 va 45 mau d 15 vao thdng 4/ 2010. Vi tri thu mdu dugc trinh bay trong hinh I.
Hgi nghj Khoa hgc vd Cdng nghi biin todn qudc lan thir V
- Phucmg phdp phdn tich trong phdng thi nghigm: Tai phdng thi nghiem mdu dugc riia sach, loai bd rac va dugc phan tich vdi cdc chi tieu; thanh phan lodi, mat dp (cd the/ m^).
Thdnh phdn lodi dugc phdn tich dua theo cdc tai lieu cua [1,2,3, 4, 5]
- Phuang phdp xu ly sd lieu
Thdng ke va xii ly sd Ii$u hen bdng tinh EXCEL.
Phan tich so dd nhdm dimg phuong phdp ket ndi nhom trung bmh dya tr6n ma trdn gidng nhau Bray_Curtis trong phdn mem Primer 5.0
Hinh 1: Sa dd trgm khdo sdt Dgng vdt thdn mem ddm Di Gi
n i . KET QUA NGHIEN CUtJ n i . l . Thanh phan loai
Ket qua phdn tich 11632 ca thi than mim thu thap trong 2 dgt khdo sat da xdc dinh dugc 56 taxon tiidn mem, trong do 35 taxon thupc ldp bai mdnh vd vd 21 taxon thupc Idp chan bung.
Mdt dieu cdn luu y Id da sd chimg deu xudt hien d giai doan du the kich thudc nhd nen viec xac dinh chmh xdc ten lodi gap nhieu khd khan va mdt sd hong chimg khdng the xdc dinh dugc. So lupng taxon xdc dinh dugc trong cd hai mua la bdng nhau (42 taxon).
Ve pban bd mat rdng, cac tram gdn cira sdng cd sd lupng lodi nhieu hon cdc ham khac (Hinb 2). Khu vuc giira dam cd sd lugng loai it hon khu vuc ven bd. Khu vuc ciia dam c6 sd lugng loai it hoac khdng cd (ham 15 va 16).
Tdn sd xuat bien cao nhdt thudc vl lodi Clithon oualaniensis (34%), kl din Id lodi Marcia cf. j aponica (31 %). 12 taxon chi xudt hien 1 Idn trong tdng so 93 lugt mau (1 %).
Tiiu ban Sinh hgc vd nguon lgi sinh vdt Biin
in.2. ivi^t dd
Mat do than mem trung binh dat 13.543 ca the/m , miia khd cao hon mua mua! Tram 14 CO mat dp than mem cao libit vdo cd 2 mua va thap nhdt Id ham 16 (d cita ddm). Cdc ham d cira sdng cd m^t dp than mem cao hon khu vyc cdn lai (Hinh 3 a va b). Uu the ve mgt dp thudc ve nhdm du the chan byng va bai mdnh vd khdng xdc dinh dugc.
III.3. Tinh chat quSn xa
Chi sd da dang cao nhdt cua thdn mem thudc ve ham 7 (Hinh 4) vao mua khd (4/2010) vd ham 13 (4/2010) mac du sd lugng loai d hai ham nay khdng phdi Id nhilu nhdt (Hinh 2). Sd dl cd dieu nay bdi d 2 tram 4 vd 14 cd tbanh phan loai nhieu nhung do mat do mdt si lodi cao nen dnh hudng den tinh da dang cung nhu tinh can bdng hong qudn xa.
Phdn tich Chi sd gidng nhau bang phdn mem Primer 5.0 cho thdy cd 4 nhdm qudn xa.
Nhom A d cdc trgm 9,10 nam d khu vyc giiia vinh, hoi cd su thay ddi thanh phdn mdt chiit theo mua. Nhdm B ^dm cac tram 6, 11 va 12 cd tinh chdt tuong ty (Hinh 5). Nhdm C gom cdc ham 4, 7 va 8 nam d khu vyc cita sdng vd cd su thay doi thaiih phdn lodi theo mua ro rSt. Cae ham cdn lai tinh chat thanh phdn lodi bien thien khdng theo I xu the nhdt dinh.
Hinh 2: Sd lugmg lodi thdn mem & cdc trgm khdo sdt
Hdi nghi Khoa hgc vd Cong nghe biin todn qudc lan thir V
Hinh 3: Mat do thdn mim a cdc trgm khdo sdt vdo mua mua (a) vd mua kho (b)
2.5
2
1.5
0.5 «
0
1 2 3 4 5 6 7 8 9 10
J (9/ 2009) J (4/ 2010)
11 12 13 H (9/2009) H" (4/ 2010)
14 15
Hinh 4: Chi sd da dgng Shannon (H) vdchisdcdn bdng Pielou (J') ddng vdt thdn n tgi cdc trgm khdo sdt trong thdng 10/2009 vd thdng 4/2010
Tieu ban Smh hgc vd ngudn tgi sinh vdi Biin
s e e s, il ^ A i
Hinh 5: Chi sd gidng nhau ve thdnh phdn lodi giua cdc trgm khdo sdt (01-15: trgm khdo sat; 09- 10: ndm khdo sdt)
Dac trung thanh phdn cua cac nhom dugc trinh bdy trong bdng 1 cho thdy d nhdm C la cac loai Batillaria zonalis vd Clithon oualaniensis thudng phdn bo d khu vuc nude Ig vd trong trudng hpp nay la khu vuc cdc cira sdng. Cdc nhdm A, B vd D uu thi bdi cac loai du the hai mdnh vd.
Bdng 1: Nhdm loal uu the ciia cdc nhdm qudn xd Nhom im the
Batillaria zonalis (Bruguiere, 1792) Biv. others
Clithon oualaniensis (Lesson, 1831) Marcia cf. japonica (Gmelin, 1791) Nassariiis sp.
Nhom A 45.13
22.31 N h o m B
49.37 32.45
N h o m C 17.7 49.3
N h o m D 29.2 30.84
i n . 4 . Thanh p h a n nguon lpi
Co khoang 12 lodi thupc 8 gidng va 5 hp than mem thupc ldp chdn bung va hai manh vo kich thudc Idn cd gia tri kinh te dugc ghi nhdn trong thanh phdn khai thdc d dam De Gi (Bang 2). Hp Arcidae co 2 lodi, hp Veneridae cd 7 loai, ca hp Psammobiidae, Batillariidae va Potamidiidae mdi hp cd 1 loai. Trong sd cdc nhdm loai khai thac, Sd (Anadara spp.), Ngheu (Meretrix spp.), Ngao (Marcia spp.) va Siit (Anomalocardia spp.) la ddi tugng ngudn lgi quan trpng nhat vdi tdng san lugng khai thdc cd thi len den 821 tdn/ndm (Bang 3).
Hgi nghi Khoa hgc vd Cong nghj bien todn quoc lan thu V
Bdng 2: Danh sdch thdnh phdn lodi thdn mem khai thdc trong ddm De Gi TT
1 2 3 4 5 6 7 8 9 10 11 12
Ten tieng Viet Sd huyet Sd
Ngheu Ben Tre Ngao Dau Ngao Rd Niiao Silt Vd thd Slit Vd min Phi OcSat Oc Hilt
Ho Arcidae Arcidae Veneridae Veneridae Veneridae Veneridae Veneridae Veneridae Veneridae Psammobiidae Batillariidae Potamidiidae
Lodi Anadara nodifera (Martens, I860) Anadara sp.
Meretrix lyrata (Sowerby, 1851) Meretrix liisorla (Roding, 1798) Marcia hiantina (Lamarck, 1818) Marcia cf. japonica (Gmelin, 1791) Anomalocardia squamosa (Linne, 1758) Anomalocardia producta Kuroda & Habe, 1951 Dosinia cf. japonica (Reeve, 1856) Gari elongata (Lamarck, 1818) Batillaria zonalis (Bruguiere, 1792) Cerithidea cingulata (Gmelin, 1790)
Bdng 3: Sdn lugng khai thdc (kg) ciia mdt sd nhom ngudn lai thdn mim trong ddm De Gi Nhom
San iLignp (kp) Ilau 90.400
So huvt't 106.800
So Lang 45.000
OcDav 69.300
Don 42.000
Phi, Ilcn 468.000
T. cOoK 821.500 IV. KET LUAN
- Da xac dinh dugc 56 taxon than mem, trong dd 35 taxon thupc ldp hai manh vo va 21 taxon thupc ldp chan bung.
- Mat dp thdn mem trung binh dat 13.543 cd the/m^, miia khd cao ban miia mua. Cac tram d ciia sdng cd mat dp than mem cao ban khu vyc cdn lgi.
- Co 12 loai thdn mem cd gid tri kinh te dugc khai thdc trong ddm D I Gi. Tdng san lugng khai thdc khoang 821 tan/nam
LCJI CAM ON
Tdc gid xin cam an Ban chii nhiem du an "''Dieu tra, ddnh gid hien trgng vd di xudt gidi phdp qudn ly tong hop Ddm De Gi theo hu&ng phdt trien ben vung" da cho phep sii dung sd lieu khdo sdt, cdc ddng nghiep xir ly thdng tin de hoan thanh bao cao nay.
TAI LIEU THAM KHAO
1. Abbott R. T., Seashells of South East Asia. Tynron Press, Scotland, 1991, 145p.
2. Abbott R.T. and S.P.Dance, Compendium of Seashells. A color Guide to More than 4200 of the World's Marine Shells. E. P. Dutton, Inc. New York, 1986,41 Op.
3. Cernohorsky W.O., Marine shells of the Pacific. Volume II. Pacific Publications. Sydney, 1972,41 lp.
4. Morris P.A., A Field Guide to Shells of the Atlantic and Gulf Coasts and the West Indies.
The Peterson Field Guide series. Houghton Mifflin Company Voston. 1972,330 pp.
5. Wye K.R., t h e Encyclopedia of Shells. Facts on File, New York, Oxford, 1991, 288p.