Tôm sú sinh thái ở Cà Mau

Tom su sinh thai o Ca IVIau<br /> LE XUAN SINK<br /> <br /> NGUYEN TRUNG CHANH<br /> <br /> <br /> 7 3 d:i viet ndy tap trung phdn tich vd so sdnh cdc chi tieu kinh te - ky thudt cung nhU<br /> J—f nhdn thac cua ngUdi nudi tdm su (Penaeus monodon) d Cd Mau - tinh sdn xudt tdm<br /> ldn nhdt ciia Viet Nam, bao gdm cd tdm su nudi theo ky thudt thdng thudng vd tdm sinh thdi.<br /> Ke't qud nghien cUu cho thdy nudi tdm su sinh thdi cd nhiiu ldi the; ngdnh hdng tdm sinh thdi<br /> cd cd hdi phdt trien td't hdn trong thdi gian tdi. Ddng thdi, bdi vie't cung di xudt mdt sd gidi<br /> phdp chu ye'u dephdt trien ngdnh hdng tdm su sinh thdi d Cd Mau.<br /> <br /> <br /> <br /> 1. Gidi thieu trfldng (nfldc, dat va suy giam nguon ldi<br /> thiiy san, cung nhfl flng phd vdi bie'n dd'i<br /> Nudi tdm su (Penaneus. monodon) d khi hau) d vflng ven bien ciia DBSCL. Vi<br /> Viet Nam da phat trien n h a n h chdng, nha't vay, hinh thflc nudi tdm sinh thai g i n day<br /> la tfl khi thflc hien ehinh sach khuye'n dfldc quan t a m phat trien d Viet Nam, di<br /> khich chuyen dd'i cd eau kinh te ndng<br /> d i u trong loai hinh nudi nay la tinh Ca<br /> nghiep de chuyen ddi nhflng vung dat<br /> Mau vdi gan 4.000 ha nudi. Nam 2000,<br /> ndng nghiep dat hieu qua tha'p sang nudi<br /> Viet Nam phdi hdp vdi Cd quan Xuc tie'n<br /> trdng thuy san. Nam 2007, dien tich nudi<br /> nhap k h a u Thuy Si (SIPPO) xay dflng va<br /> tdm ven bien ciia Viet Nam la 624.586 ha<br /> trien khai thflc hien chfldng trinh nudi<br /> vdi san Ifldng 383.608 tan va kim ngach<br /> tdm sinh thai tai tinh Ca Mau. SIPPO da<br /> xua't khau tren 1,5 ty USD. Nudi tdm su<br /> chflng n h a n cho 831 ho nudi tdm, 30 dai ly<br /> dae biet dfldc quan tam d Ddng bang sdng<br /> va 1 doanh nghiep che bie'n xuat khau<br /> Ciin Ldng (DBSCL) ndi thfldng xuyen<br /> thuy san dat tieu chuan Naturland. San<br /> chiem khoang 85% td'ng dien tich va 80%<br /> pham tdm sinh thai Viet Nam dfldc ban<br /> san Ifldng tdm nudi ciia Viet Nam (Bd<br /> qua Thuy Si. Vdi dien tich 3.593 ha va<br /> Thuy san, va Bd Ndng nghiep va Phat trien<br /> 1.261 ho nudi tdm t h a m gia, san Ifldng tdm<br /> ndng thdn, 2002 va 2007). Tinh Ca Mau cd<br /> sinh thai t h u hoach trong 2006 va 2007 la<br /> dien tich va san Ifldng tdm nudi ldn nha't ca<br /> nfldc (rat it nudi tham canh/ban tham canh). 675 tan va 1.000 tan, vdi kim ngach xuat<br /> Day eung la ndi ma vai trd ciia rflng ngap k h a u tfldng flng la 2,656 va 4,668 trieu<br /> man va nguon ldi thuy san ven bien la dac USD (Sd Thuy san Ca Mau, 2005 va 2007).<br /> biet quan trong. San pham thiiy san sinh thai ed nhflng<br /> flu diem ve an toan thflc pham, gia ban<br /> Tuy nhien, viec phat trie'n nudi tdm tfl<br /> tdm sinh t h a i eao hdn k h o a n g 20% so vdi<br /> phat d cac vflng ven bie'n trong sud't thdi<br /> tdm thdng thfldng, giup giai quye't van de<br /> gian qua da va dang gay ra rat nhieu van<br /> de ve kinh te-xa hdi, an toan ve sinh thflc<br /> pham (ATVSTP) va thfldng mai thuy san, Le Xuan Sinh, Trudng Dai hoc Cin Tha; Nguyen<br /> cung nhfl l a m , t a n g mfle do d n h i i m mdi Trung Chanh, Chi cue Thuy san tinh Ca Mau.<br /> <br /> <br /> 38<br />  Tom su sinh thdi ...<br /> <br /> <br /> mdi trfldng, bao ve nguon ldi thuy san va biet ve cae chi tieu kinh te-ky thuat, eung<br /> phat trien rflng ngap man, ... Tuy nhien, nhfl nhan thflc ve nhflng van de chu ye'u<br /> nganh h^ng tdm sinh thai d Ca Mau va ciia cac nhdm ddi tfldng nghien cflu. Phan<br /> Vi§t Nam chfla phat trien nhfl mong ddi. tich tfldng quan da bie'n dfldc ap dung de<br /> Nhflng ngfldi ngheo khdng cd cd hoi de sii phan tich eac ye'u td' X^ anh hfldng mot<br /> dung ngudn thflc p h l m nay va nang s u i t each ed y nghia de'n Y; (nang s u i t tdm<br /> nudi tdm sinh thai tren the gidi dat tha'p nudi) theo dang ham Cobb-Douglas:<br /> (200-300 kg/ha/nam) cung la mot ban che<br /> rat ldn (Thieu Lfl, 2004). Nghien cflu nay<br /> Y,=A,-x,".xr'-'-xr<br /> dfldc thflc hien nham phan tich hien trang Phan tich tfldng quan da bie'n eung dflde<br /> cac chi tieu kinh te-ky thuat, cung nhfl ap dung de phan tich cac yeu td' X^, anh<br /> cac yeu td' tac ddng va n h a n thflc cua eac hfldng mot each cd y nghia de'n Yj (tong chi<br /> nhdm ho nudi tdm su bao gdm ea tdm su phi bie'n ddi trong san xuat gid'ng va trong<br /> nudi theo ky t h u a t TTT va tdm sinh thai d nudi tdm thit) theo dang ham Semi-log<br /> Ca Mau. Tfl dd de xua't cac giai phap cd nhfl sau:<br /> ban n h l m gdp p h i n phat trien nganh IgY, = A, + Bi.Xi + B2.X2 + ....+ B„.X„<br /> bang tdm su ndi chung va tdm sinh thai 3. Ke't qua va t h a o l u a n<br /> ndi rieng mot each hdp ly hdn d tinh Ca<br /> Mau va Viet Nam. 3.1. Thdng tin chung ve cdc hg nuoi<br /> tdm sU<br /> 2. Phiitfng phap n g h i e n ciiu<br /> Nudi tdm thdng thfldng da xua't bien d<br /> Cac boat ddng ciia nghien cflu nay dfldc<br /> DBSCL tfl cudi nhflng nam 1980, nhflng<br /> tie'n banh tfl thang 7-2007 de'n thang 6-<br /> kinh nghiem nudi tdm sinh thai chi mdi<br /> 2008 tai dia ban cac huyen Nam Can,<br /> bat d i u khoang 3 den 4 nam. Nudi tdm su<br /> Ngoc Hien, Phu Tan va T r i n Van Thdi cua<br /> hau het thudc sd hflu tfl nhan va ho gia<br /> tinh Ca Mau. Sd' lieu thfl cap dfldc thu<br /> dinh. Ho nudi tdm nhin chung khdng<br /> thap de lam ro xu hfldng chung eua nganh<br /> mfldn them lao ddng va ho tie'p can cac<br /> bang tdm su, bao gdm ca tdm sinh thai va<br /> thdng tin kinh te-ky t h u a t tfl rat nhieu<br /> tdm thdng thfldng. Nganh bang tdm su<br /> ngudn. Tu rut kinh nghiem trong san xua't<br /> dfldc the bien tdm tat b l n g sd dd sau:<br /> va tie'p thu qua phfldng tien thdng tin dai<br /> Sdn xudt gid'ng -> Nudi tdm thit -> Thu chung (tivi, dai, bao) chie'm ty le eao<br /> mua tdm nguyen lieu —> Che bien xudt (tfldng flng 91,8% va 90,5% sd' ho dflde<br /> khdu khao sat). Sfl quan tam hd trd eiia cac ban,<br /> Sd' lieu sd ca'p dfldc thu d l y dii tfl cac nganh thiiy san dia phfldng ma chii yeu la<br /> nhdm tac nhan tham gia nganh hang, Trung tam Khuye'n ngfl trflc tie'p tap hua'n<br /> nhflng trong bai vie't nay chi tap trung ve khoa hoc ky t h u a t dfldc 81,6% sd' ndng<br /> phan tich thdng tin lien quan tdi cac ho ho tie'p nhan. Ngoai ra, ed 58,2% sd' ho<br /> nudi tdm su, bao gom: (1) 50 ho nudi tdm nudi tdm coi trong viec trao dd'i kinh<br /> sinh thai, (2) 30 ho ngflng nudi tdm sinh nghiem vdi ndng dan khac. Nhflng tuye'n<br /> thai, (3) 30 bd chfla nudi tdm sinh thai thdng tin nay c l n dfldc lflu y de nang cae<br /> trong vflng dfl an nudi tdm sinh thai, va hieu qua eua boat ddng truyen thdng lien<br /> (4) 50 ho nudi tdm thdng thfldng (tdm-rflng quan tdi nudi thuy san va quan ly vung<br /> va chuyen tdm, nam ngoai vflng dfl an tdm ven bien.<br /> sinh thai). Tat ca eac ho trong khu vflc dfl an nudi<br /> Phfldng phap thd'ng ke md ta va so sanh tdm sinh thai deu nam bat dfldc thdng tin<br /> d\i(}c dflng de md ta va phan tich sfl khac ve tdm sinh thai, nhflng chi cd 62,5% sd' ho<br /> <br /> Nghiin ciiu Kinh te so 376 - Thing 9/2009 39<br />  Tom su sinh thdi...<br /> <br /> <br /> dang ap dung. 0 nhdm nudi tdm thdng 3.2. Cdc chi tieu kinh te-ky thudt<br /> thfldng cd tdi 83,7% sd' ho khdng n l m chu yeu cda nhitng hg nudi torn su<br /> dfldc thdng tin ve tdm sinh thai, sd' cdn Dien tich da't canh tae t r u n g binh eua<br /> lai (16,3%) tuy da n l m dfldc thdng tin ve eac ho dfldc khao sat (4,7 ha) cao hdn dien<br /> tdm sinh thai nhflng chfla ap dung. Dieu tich da't nudi tdm binh quan cua tinh (3,3<br /> kien b i t budc khi t h a m gia nudi tdm sinh ha) do n l m trong nhflng dia ban ed dat<br /> thai dflde cac hd khao sat cho biet bao rflng (Sd Thuy san Ca Mau, 2005). Td'ng<br /> gom: (i) td' chflc nudi theo quy trinh nudi dien tich da't t r u n g binh cua ho nudi tdm<br /> tdm sinh thai (100% sd' ho); (ii) dam bao sinh thai khoang 5,9 ha, trong do ty le<br /> dien tich rflng chie'm 70% tong dien tich mfldng chie'm khoang 49,8%, cdn lai la ty<br /> canh tac (100%); va (iii) tuyet ddi khdng le rflng 50,2%, vdi do sau mfle nfldc trong<br /> sii dung hda cha't (100%). Cac hd nudi tdm mfldng khoang 1,1 m. Cac ho ngflng nudi<br /> sinh thai cho biet cac ly do ho t h a m gia tdm sinh thai cd dien tich nudi trung binh<br /> nganh hang tdm sinh thai vi nhflng ly do: 5,2 ha va ty le mfldng 52,7 % vdi ty le rflng<br /> (i) gia tdm sinh thai d'n dinh, de tieu thu 47,3%. Cac ho nudi tdm thdng thfldng<br /> (57,1% sd' ho); (ii) ldi n h u a n dflde tang trdng vflng dfl an ciia Lam trfldng 184 cd<br /> them de tdm sinh thai mang lai (49,0%); dien tich trung binh 4,6 ha, ty le mfldng<br /> (iii) dap flng dfldc dieu kien nudi tdm sinh 43,8% vdi ty le rflng khoang 56,2%. Trong<br /> thai (49,0%); (iv) la md hinh ed hieu qua khi dd, cac ho nudi tdm thdng thfldng<br /> va ben vflng (10,2%); (v) ehi phi d i u tfl ngdai vung dfl an cd dien tich binh quan<br /> thap, de cham sdc va it riii ro (63,8%); (vi) 3,5 ha vdi ty le mfldng ra't cao (65,8%) va<br /> • theo sfl khuye'n khich eiia lam trfldng ty le rflng ehi khoang 34,2%). Nhfl vay, h l u<br /> (8,2%); (vii) dflde tap hua'n ky t h u a t theo het cae ho dang hay da ngflng nudi tdm<br /> quy trinh nudi tdm sinh thai (6,1%). sinh thai va dang nudi tdm thdng thfldng<br /> Ly do de mot sd' ho da cha'm dflt hdp khdng dap flng dflde qui dinh ve ty le rflng<br /> dong nudi tdm sinh thai gdm ed: (i) ty le cho nudi tdm sinh thai. Can ed chinh sach<br /> rflng khdng dii dieu kien nudi tdm sinh khuye'n khich n h a m t a n g ty le rflng hoac<br /> thai (55,6%); (ii) vi pham hdp ddng nudi phai cd sfl dieu chinh quy dinh ve ty le<br /> tdm sinh thai (51,9%); (iii) khdng dap rflng trong nudi tdm sinh thai cho phfl hdp<br /> flng dflde cae yeu c l u khac cua nudi tdm vdi dieu kien d nhflng vflng dflde quy<br /> sinh thai (22,2%); (iv) nudi theo quy hoach nudi tdm sinh thai.<br /> trinh tdm sinh thai khdng dat hieu qua Nhin chung, cac hg nudi tdm sen vet 1<br /> (3,7%). lan/nam (65,6% so' ho) tap trung theo quy<br /> Nhflng ho nudi tdm sinh thai deu phai dinh trong vdng 1 t h a n g cu the, thfldng la<br /> ky ke't hdp ddng vdi lam trfldng, khi thang 7 am lich (70,5% sd' ho trong nhdm<br /> cham dflt hdp ddng thi dieu kien b i t budc sen 1 lln/nam), sd' cdn lai sen vet 2 lln<br /> la phai phuc hoi ty le rflng dung theo quy trong nam vdi viec sen vet l l n d i u vao<br /> dinh (96,2% sd' ho) va phai boi thfldng thang 1-2 am lich (90,7% sd' ho eua nhdm<br /> khi pha vd hdp ddng (11,5%). Cac ho nudi nay), va 91,0% sen vet lan 2 vao thang 7-8<br /> tdm thdng thfldng neu ly do de ho khdng am lich. Do day Idp sinh bun phai sen vet<br /> tham gia nudi tdm sinh thai la do: (i) quy binh quan khoang 34,9 cm the hien mfle<br /> trinh nudi tdm sinh thai khd ap dung do boi lang ra't n h a n h cua cac ao nudi tdm,<br /> (28,0% sd' ho); (ii) thie'u vd'n san xua't ddng thdi lam t a n g lo ngai ve ndi ehfla<br /> (44,0%); (iii) gia tdm khdng d'n dinh eung nhfl viec xii ly Idp sinh bun dflde sen<br /> (28,0%); va (iv) khdng dam bao dflde ty le vet nay. Da so' cac hp nudi tdm deu do' sinh<br /> rflng theo quy dinh (40,0%). bun tren bd khi sen vet (87,2%) va so' cdn<br /> <br /> 40 Nghiin cCtu Kinh ti si 376 - Thing 9/2009<br />  Tom su sinh thdi ...<br /> <br /> <br /> lai cd bao bd cho mdt khu xfl ly sinh bfln cdn/m^. Do ap dung hinh thflc nudi quang<br /> rieng (vdi tdm sinh thai tfldng flng la 76% eanh hoac quang canh cai tien nen cac ho<br /> va 24%). Nhfl vay, y thflc cua ngfldi nudi ehi t h i tdm gid'ng khdng cho an, vi vay chi<br /> tdm tai dia ban da ed thay dd'i dang ke so phi mua tdm gid'ng thfldng chie'm ty le kha<br /> vdi nam 2004, khi dd 20% sd' ho nudi tdm cao (28,6% trong td'ng ehi phi bie'n dd'i). De<br /> xa sinh bun khi sen vet ao mfldng trflc tiep tang thu nhap va cd them thflc pham, cac<br /> ra sdng rach (Le Xuan Sinh va ctv, 2005). ho nudi tdm thfldng tha them cua hoac ea<br /> Hien nay, chi phi sen vet va cai tao ao vdi mat do tha'p nen ehi phi gid'ng bd sung<br /> mfldng chie'm ty le cao n h a t trong tdng ehi chie'm ty le tha'p hdn (12,4%).<br /> phi bie'n dd'i (41,1%). Viee xay dflng cdng trinh nudi cua h l u<br /> Tdm su gid'ng chii ye'u dfldc mua tfl cac bet eac ho nudi tdm tai dia ban khao sat<br /> trai san xua't gid'ng tai dia phfldng (85,6% cdn chfla tuan thu quy trinh ky thuat, ho<br /> sd bd nudi) va hien dfldc cae ho nudi fla thudng sfl dung chung mot kenh cho ea<br /> chudng bdn so vdi tdm gid'ng nhap tfl cac ca'p va thoat nfldc (93,1%) sd' ho). Hau bet<br /> tinh khac (74,4% sd' ho). Gid'ng tdm sinh cae ho nudi tdm chfla chu y nhieu tdi viee<br /> thai cbi dfldc san xua't trdng tinh Ca Mau quan ly nguon nfldc. Nfldc cho nudi tdm su<br /> va ehi dfldc nhdm ho nudi tdm sinh thai d dfldc la'y trflc tie'p tfl sdng rach chie'm ty le<br /> day ebon mua de tha nudi. Kiem dich tdm ra't cao (98,1% sd'ho) va ehi cd 1,9% sd'ho<br /> su gid'ng (xet nghiem) dfldc h l u het cac cd sii dung ao lang cho nudi tdm. Ngfldi-<br /> nhdm ho nudi nhan thflc la quan trong va nudi tdm thfldng ket hdp thay nfldc va thu<br /> dfldc thflc hien vdi ty le ra't cao nhfl nhdm hoach tdm theo cac eon nUde xd, dinh ky<br /> cae bd nudi tdm sinh thai (98,0% sd' ho), mdi thang 2 l l n v^o thdi diem nhflng ngay<br /> r)bdm cac bd ngflng nudi tdm sinh thai: nfldc cfldng (12,9 ± 2,9 ngay/lln). Thay<br /> 90,0% va nhdm cae ho nudi tdm thdng nfldc nhieu l l n trong thang se lam cho<br /> thfldng: 84,0%. Tuy nhien, phfldng phap ehudi thflc an tfl nhien trong ao nudi phat<br /> kiem dich nae dfldc ap dung mot each rdng trien cham, ba't ldi cho nudi tdm (DANIDA<br /> rai va hieu qua thi c l n dfl. 04 tiT nhien 13,9% CatU nhien<br /> sy^^- r 13,4% 1,8%<br /> Cua nudi M M j K ^ ^ ^ i<br /> 140<br /> ,% m i p M<br /> W^.W'.',','.',<br /> l'!'!^^-~~^ Cei nuoi<br /> ^ ^ ^ ^ ^ ^ ^ . 1<br /> 0 ^ 0,0% Ca nuoi<br /> T6m s u _ , - - — ' " ' Tom su 0,1%<br /> 39,5% 70,5%<br /> <br /> <br /> <br /> <br /> Ldi nhuan binh quan /ha md hinh/nam kha ldn (±30,1) vdi ty le bi thua Id chie'm<br /> ciia cac ho nudi tdm la 7,65 trieu ddng va cd 15,0% tdng sd' hd khao sat. Ke't qua nay<br /> sfl chenh lech kha ldn gifla cac nhdm va cac cao bdn ke't qua thd'ng ke eua Sd Thuy san<br /> hd cung nhdm. Trong dd, cae ho nudi tdm Ca Mau n a m 2007 (vdi md hinh tdm rflng<br /> sinh thai cd ldi nhuan cao nha't (11,78 trieu nam 2007 la 10%) nhflng k h a quan bdn so<br /> dong) va tha'p nhat la nhdm ho da ngflng vdi binh quan chung eiia nghe nudi tdm<br /> nudi tdm sinh thai (2,49 trieu ddng). bien d DBSCL (binh quan hang nam ed<br /> Nguyen nhan la do cae ho nudi tdm sinh 25-30% sd' hd nudi tdm bi Id; Le Xuan<br /> thai ban dfldc tdm nudi vdi gia cao hdn 20% Sinh va Phan Thi Ngoc Khuyen, 2006). Ty<br /> so vdi tdm thdng thfldng, dong thdi chi phi le thua Id cua cae ho ngflng nudi tdm sinh<br /> va nang s u i t cd chieu hfldng thuan ldi hdn thai la eao nha't (26,7% sd' ho cua nhdm),<br /> chd ngfldi nudi tdm sinh thai. nhflng cac ho nudi tdm sinh thai tiep tuc<br /> Ty s u i t ldi n h u a n binh quan chung ciia cd ldi the ciia minh vdi chi 4,0% sd' bd eua<br /> cac ho nudi tdm Ja 31,2%/nam va dao ddng nhdm ho nay bi t h u a Id.<br /> <br /> <br /> Nghiin cuu Kinh ti si 376 - Thing 9/2009 43<br />  Tom su sinh thdi...<br /> <br /> <br /> Bang 1. Cac c h i t i e u c h u y e u c u a c a c m o h i n h n u o i torn s u dxidc k h a o s a t (2008)<br /> <br /> Don v| Ngimg Chira<br /> Khoan muc Nuoi TST Nuoi TTT Tdng<br /> tinh nuoi TST nuoi TST<br /> <br /> Sd hg khdo sdt n 50 30 30 50 160 1<br /> 1. Tdng dien tich ciia ndng hd<br /> - Trung binh ha 5,9 5,2 4,6 3,5 4,7<br /> - Dd lech ehuan ha 3,7 1,9 2,2 1,6 2,8<br /> 2. Mat do tdm gid'ng/nam<br /> - Trung binh PL/m' 12,7 8,6 13,1 11,5 11,6<br /> - Do lech chuan PL/m' 8,2 4,3 6,5 6,3 6,8<br /> 3. Nang suai tdm sii/ha mat nudc/nam<br /> - Trung binh kg 218,3 120,5 192,4 178,9 182,8<br /> - Dd lech chudn kg 161,2 49,7 212,5 144,1 155,7<br /> 4. Nang sua't tdm su/ha md hinh/nam<br /> - Trung binh kg 97,4 63,9 71,7 109,8 90,2<br /> - Dd lech chuin kg 54,0 31,8 46,4 71,9 58,3<br /> 5. Chi phi /ha md hinh/nam<br /> - Trung binh lOOOd 9.406,9 10.939,3 8.847,8 12.162,1 10.450,4<br /> - Dd lech chuan lOOOd 3.071,0 4.043,4 3.287,0 3.838,3 3.767,3<br /> 6. Lai nhuan /ha md hinh/nam<br /> - Trung binh lOOOd 11.776,9 2.489,5 4.377,9 8.590,6 7.652,5<br /> - Dd lech ehuan lOOOd 9.570,1 3.911,0 4.957,8 10.808,1 9.174,8<br /> 7. Ty suai Igi nhuan/nam<br /> - Trung binh % 47,2 13,2 26,9 28,7 31,2<br /> - Dd lech ehuan % 24,0 24,8 24,5 34,1 30,1<br /> 8. Ty le sd hd nudi tdm cd lai (ldi) % 96,0 73,3 86,7 80,0 85,0<br /> <br /> <br /> Phan tich tfldng quan da bie'n ddi vdi (v) Mfle nfldc trong mfldng nen duy tri d<br /> nang suat tdm va chi phi nudi giup de xua't mfle 1,1-1,2 m.<br /> met sd' khuye'n eao gdp phan cai thien hieu<br /> qua kinh te-ky thuat trong nudi tdm nhfl (vi) Mat do tdm gid'ng tha/nam nen trong<br /> sau: khoang 9-12 con/m^.<br /> <br /> (i) Nudi tdm sinh thai td't hdn nudi tdm (vii) Mat do eua tha bd' sung/nam nen d<br /> thdng thfldng ve nhieu mat. mfle 0,13-0,16 eon/ml<br /> (ii) Td'ng dien tich md hinh 2,5-3,5 ha la (viii) So'lan tha gid'ng nen la 4-5 lln/nam.<br /> hdp ly. (ix) Ty le thay nfldc 40-50%/lln la td't<br /> (iii) Ty le dien tich rflng/ td'ng dien tich nha't. '-••'••<br /> md hinh trong khoang 50-60% la phfl hdp. (x) Sd' lan thu hoach/nam nen trong<br /> (iv) Nen cai tao ao mfldng 2 lln/nam. khoang 18-22 l l n (theo con nfldc).<br /> <br /> 44 Nghiin ciiu Kinh ti si 376 - Thing 9/2009<br />  Tom su sinh thdi<br /> <br /> <br /> 3.3. Nhdn thitc ve ngdnh hdng tom su pha nhieu hdn. Pham Van Suy (2007) eung<br /> Tdc ddng vi mat xd hdi: ngfldi nudi tdm canh bad nguy cd can kiet ngudn ldi tdm su<br /> su cho rang nganh hang nay ed tac ddng rat bd' me ngoai tfl nhien ne'u khdng cd bien<br /> ldn ve xa hdi. Khi nhieu ngfldi nudi thanh phap phu hdp de quan ly cac boat ddng khai<br /> cdng va thanh cdng qua nhieu vu thi thu thae va sfl dung tdm su bd' me. Tac gia nay<br /> nhap eua cae ho nay gia tang va kinh te dia cho biet hang nam cd khoang 86.500 tdm su<br /> phfldng phat trien mang lai anh hfldng ve xa cai trudng thanh va 36.500 tdm su diic<br /> hdi. Tuy nhien, mfle dd rui ro trong nudi tdm trfldng thanh dflde khai thac tfl vflng bien<br /> cao, khi ngfldi nudi tdm bi thua Id thi cd hdi cua Ca Mau de eung ca'p cho cac trai san<br /> mat da't, nd n i n va that hdc la rat de xay ra, xuat tdm gid'ng d dia phfldng, cac tinh dong<br /> nha't la vdi nhflng ho ed dien tich nhd va bang sdng Ciiu Long va Mien Trung. Cd the<br /> khdng cd nganh nghe khae. Cae te nan xa sii dung tdm su me cho de tdi l l n thfl tfl van<br /> hdi thfldng tang theo mfle do tha't bai trong dam bao dfldc chat Ifldng cua tdm gid'ng va<br /> nudi trdng thiiy san d cac vflng nudi gid'ng giup giam bdt viec khai thac tdm cai se vdi<br /> nhfl trong nghien cflu eiia Le Xuan Sinh va khuye'n cae cua Bd Thuy san chi sfl dung<br /> ctv (2005). Khi thi trfldng tieu thu tdm tdm me cho de 3 l l n (Sinh, 2004).<br /> khdng thuan ldi thi ddi sd'ng ra't nhieu ho<br /> Nganh hang tdm sinh thai d Ca Mau<br /> nudi tdm trd nen khd khan hdn (Le Xuan<br /> dflde nhan dinh la se tie'p tuc phat trien<br /> Sinh va Nguyin Trung Chanh, 2006).<br /> trong thdi gian tdi vdi sfl iing ho eua 41,3%<br /> Tdc ddng vi an todn ve sinh thUc phdm: sd' ho nudi tdm. Thuan ldi cd ban phat trien<br /> cac san pham tdm, dac biet la tdm su, chu nganh hang tdm sinh thai la:<br /> ye'u dfldc che bie'n va xuat khau, vi vay yeu<br /> clu ve an toan ve sinh thflc pham ngay cang (i) Dien tich rflng san cd trong cac md<br /> dfldc quan tam. Ca ngfldi san xua't gid'ng va hinh rflng-tdm ra't de chuyen qua nudi tdm<br /> ngfldi nudi cho la tae ddng nay d mfle binh sinh thai. .<br /> thfldng. Nhflng ngfldi tham gia lam tdm (ii) Tieu thu tdm sinh thai ra't thuan ldi,<br /> sinh thai ed nhan thflc ve an toan ve sinh ed gia cae hdn va dn dinh Hdn so vdi tdm<br /> thflc pham td't hdn nhdm cdn lai. Tuy nhien, thdng thfldng.<br /> treng mua ban va che bie'n tdm nguyen lieu<br /> (iii) Nha nfldc ed mot sd' chinh sach<br /> thdi gian qua da cd nhieu hien tfldng rat<br /> khuye'n khich nudi tdm sinh thai, cac cd<br /> dang quan ngai ve chat Ifldng tdm nguyen<br /> quan chuyen mdn va doanh nghiep ehe bie'n<br /> lieu, nha't la qua cac khau trung gian (Le<br /> xuat khau tdm sinh thai hd trd ve ky thuat<br /> Xuan Sinh va Phan Thi Ngec Khuyen,<br /> va tieu thu san pham.<br /> 2006).<br /> (iv) Nudi tdm sinh thai cd chi phi tha'p,<br /> Tdc dong ve mdi trUdng: nguen gay d<br /> de cham sdc, it rui ro va mdi trfldng ao nudi<br /> nhiem chd ad nudi tfl cae trai san xua't tdm<br /> dn dinh.<br /> gid'ng dfldc cac hd nudi tdm xac nhan chie'm<br /> ty le ra't eao (45,7% sd' ho), ke de'n la tfl vfla Quye't dinh trong thdi gian tdi cua eac<br /> thu mua tdm (15,7%). Cd tdi 70% sd' ngfldi nhdm ho nudi cflng dflde phan tich. Cd<br /> nudi tdm cho r i n g viec xii ly sinh bun khi 62,5% so ho nudi tdm sinh thai se tie'p tuc<br /> sen vet, nfldc thai va sii dung hda cha't/thud'c nudi tdm sinh thai, nhflng cung cd tdi<br /> trong san xuat cln dflde quan tam hdn nfla, 33,8% so' ho mud'n cham dflt hdp dong do<br /> nha't la ddi vdi nhdm v. C l n lflu y ring: that khdng dam bao ty le rflng theo quy djnh. Cd<br /> bai trong nudi tdm lam tang mfle do khai 3,8% sd' ho trfldc day cham dflt hdp ddng<br /> thac nguon ldi thuy san tfl nhien d vung ven nudi tdm sinh thai nay mud'n quay lai ky<br /> bien va rflng ngap man ed nguy cd bi tan hdp dong de tie'p tuc nudi tdm sinh thai do<br /> <br /> Nghiin ciiu Kinh te s6 376 - Thing 9/2009 45<br />  Tom su sinh thdi...<br /> <br /> <br /> da trong lai rflng dung quy dinh. Ly do eac (vi) Chfla md rdng dfldc thi trfldng xua't<br /> ho nudi tdm dfla ra de tie'p tue hoac se tham khau nen nganh hang tdm sinh t h a i cdn<br /> gia nudi tdm sinh t h a i thdi gian tdi gdm: phat trien mot each ra't h a n che (5%).<br /> (xi) Tdm it benh, de nudi, it phai sii dung Cac giai phap ed ban n h l m gdp p h i n han<br /> thud'e (68%). che khd khan de phat trien nganh hang tdm<br /> sinh t h a i d cap do dia phfldng va nganh<br /> (xii) Tie'p tuc dfldc hfldng ty le tang gia do<br /> thiiy san dfldc nhflng ngfldi tham gia de<br /> tdm sinh thai mang lai (55,7%).<br /> xua't nhfl sau:<br /> (xiii) De cd mat hang mdi va thi trfldng<br /> (i) Tang cfldng tap hua'n ky thuat ve quy<br /> xuat khau mdi sd vdi trfldc (50%).<br /> trinh san xua't gid'ng va nudi tdm sinh thai.<br /> (xiv) De van hanh ed sd san xua't tie'p tuc<br /> (ii) Cung ca'p tdm gid'ng tdm sinh thai<br /> d'n dinh va phat trien (40,0%).<br /> cha't Ifldng cao cho eac vflng nudi thee quy<br /> (xv) Dien tich da't rflng va ty le rflng hoach.<br /> thich hdp cho nudi tdm sinh thai (25,7%). (iii) Nghien cflu dieu chinh ty le rflng -<br /> (xvi) Giup tang thu nhap dn dinh cude tdm phfl hdp cho md hinh nudi tdm sinh<br /> sd'ng cua gia dinh (6,3%). thai.<br /> (xvii) Gdp p h i n nang cao uy tin ciia thfldng (iv) Da dang ddi tfldng san pham sinh<br /> hieu tdm sinh thai ciia Ca Mau (20%). thai de cd nhieu san pham va giam rui ro.<br /> (xviii) Mud'n da dang mat hang, khdng bi (v) Quy hoach lai vflng nudi tdm sinh<br /> rang bude vi mot loai san pham (10%). t h a i hdp ly hdn de thuan ldi trong d i u tfl va<br /> (xix) Ne'u da tham gia lam tdm sinh thai giam dfldc nhflng tae dong ba't ldi tfl cac<br /> ma pha vd hdp ddng thi phai boi thfldng vflng nudi lan can.<br /> (1,4%). (vi) D i u tfl phat trien ddng bd cac phan<br /> Tuy nhien, sfl phat trien nganh hang tdm doan eua ea nganh hang, tfl san xua't gid'ng<br /> sinh thai dflde chd la gap phai mot sd' khd tdi nudi, thu mua, bao quan tdm nguyen lieu<br /> khan ma nhflng ngfldi tham gia de cap tdi, va ehe bie'n/tieu thu san pham.<br /> nhfl: (vii) Tang cfldng cae chinh sach khuye'n<br /> (i) Nguon nfldc ehfla td't hoac khdng khich phat trien nganh hang tdm sinh thai<br /> dflde quan ly td't nen benh tdm edn xua't hien nhanh hdn nfla theo hfldng ben vflng eua<br /> nhieu (53,1%). nganh va dia phfldng.<br /> (ii) Khoang 20,9% sd' ho nudi tdm sinh Cac ho nudi tdm sinh t h a i cd nhflng giai<br /> thai lo ngai thu nhap bi giam do viec ngfldi phap n h l m khac phuc khd khan cua ho nudi<br /> thu mua ehi quan tam tdm sinh thai cd tdm sinh t h a i nhfl:<br /> kich cd ldn nhflng khdng mua tdm su cd kich (i) C l n cd trai san xua't gid'ng tdm sinh<br /> ed nhd va eac loai tdm khae trong cflng md t h a i cha't Ifldng cao eung ca'p du sd' Ifldng<br /> hinh theo gia san pham sinh thai. ehe ngfldi nudi (59,0% so'ho).<br /> (iii) Cha't Ifldng tdm gid'ng ehfla d'n dinh (ii) Tang mat do tdm gid'ng tha nudi so<br /> (18,8%). vdi hien nay ne'u sd'lan tha it (35,9%).<br /> (iv) Ty le rflng- tdm 7/3 edn chfla hdp ly vi (iii) Nen to chflc t h u mua tdm sinh thai<br /> khdng cd sfl khac biet ve cha't Ifldng nfldc (va cd kich cd khac nhau de dam bao quyen ldi<br /> chfla ed nghien cflu ve chat Ifldng tdm) cua ngfldi nudi (23,1%).<br /> (15,6%). (iv) Can cd giai phap giup on dinh gia<br /> (v) Thie'u vd'n san xua't va thie'u ky thuat tdm nguyen lieu (17,9%).<br /> nudi phfl hdp nen nang sua't tdm nudi cdn (v) Tang cfldng tap hua'n ky thuat nudi<br /> thap (10%). theo quy trinh nudi tdm sinh t h a i (15,4%).<br /> <br /> 46 Nghiin ciru Kinh te so 376 - Thing 9/2009<br />  Tom su sinh thdi ..<br /> <br /> <br /> (vi) Giam ty le rflng theo quy d i n h b i e n (6) C l n n g h i e n cflu t h e m ve ty le<br /> nay hoac ebo tia thfla bdt rflng de tdm nudi rflng/td'ng dien tich n u d i t h i c h hdp c u n g<br /> cd the p h a t trien td't hdn (15,4%). nhfl k h a i t h a c hdp ly n g u d n tdm bd' me tii<br /> 4. K e t l u a n v a d e x u a t n h i e n va d a d a n g gid'ng loai t h u y san trong<br /> k h u vfle nudi./.<br /> Cac ke't q u a tfl n g h i e n cflu n a y cho tha'y<br /> cac tac n h a n t h a m gia s a n x u a t , n u d i va<br /> m u a b a n tdm s u s i n h t h a i d e u cd nhflng ldi TAI LIEU THAM KHAO<br /> t h e nhfl: h i e u q u a k i n h t e cao hdn, giup da<br /> d a n g s a n p h a m t h u y s a n v a it r u i ro h d n (1) Bd Thiiy san (2002). Bao eao tdng kei hang nam.<br /> cung nhfl it gay t a c d d n g x a u tdi mdi (2) Bo Thiiy sin (2003). Tieu chi nudi torn sinh thai.<br /> trfldng h d n sd vdi cac md h i n h n u d i t d m (3) Bd Thuy san (2006). Bao cao tdng ket hang nam.<br /> thdng thfldng, nha't la cd t a c d d n g tich cflc (4)Bd Thuy san va DANIDA (2005). Hudng din<br /> tdi nguon ldi t h u y s a n v a rflng n g a p m a n . thuc hanh quan ly tdt trai sin xuit tdm sii gid'ng d Viet<br /> Nam.<br /> Cac n h d m tac n h a n d e u ed ty le cao u n g ho<br /> (5)FAO (2004). State of world's fisheries and<br /> cho sfl p h a t t r i e n cua n g a n h h a n g t d m<br /> aquaculture.<br /> sinh t h a i . (6)FA0 (2006). State of world's fisheries and<br /> Nhflng khd k h a n t r o n g p h a t t r i e n n g a n h aquaculture.<br /> h a n g tdm s i n h t h a i c h u ye'u la ve n g u d n (7) Le Xuan Sinh va Phan Thi Ngpc Khuyen (2006).<br /> nfldc, gid'ng, ky t h u a t va t h i trfldng. De Nganh hang tdm su d ddng bang sdng Ciru Long: nhin<br /> t\s gdc dd eung ca'p tdm nguyen lieu cho che' bie'n xuit<br /> p h a t trien n g a n h h a n g t d m s i n h t h a i ndi<br /> khau. Bao cao trinh bay tai Hdi thao qud'c te ve "Plidt<br /> rieng va tdm su ndi c h u n g m o t each hdp ly trie'n Klioa hgc-cdng nghe phuc vu cdng nghiep hda,<br /> n h a m gdp p h i n p h a t t r i e n k i n h te-xa hdi hien dgi hda ngdnh thiiy sdn " td chirc tai Dai hoc Nha<br /> cung nhfl bao ve va p h a t t r i e n h e sinh t h a i Trang, 16-17-11-2007.<br /> rflng ngap m a n va n g u d n ldi t h u y s a n ven (8) Le Xuan Sinh (2005). Nghien euru kinh te-xa<br /> bien cua tinb, c l n q u a n t a m nhflng de x u a t hdi phuc vu cdng tac quy hoach NTTS d huyen Nam<br /> sau: Can va Ngoc Hien, tinh Ca Mau. Bao eao tu va'n, Du an<br /> Hd tra phat trie'n nudi trdng thiiy sin man Ig (SUMA) -<br /> (1) Quy b e a c h lai cac v u n g n u d i tdm, Bd Thuy sin va DANIDA.<br /> nha't la tdm s i n h t h a i bdp ly h d n de g i a m (9) Le Xuan Sinh va Phan Thi Ngoc Khuyen, Dd<br /> tac ddng b a t ldi tdi mdi trfldng va t a c ddng Minh Chung, Huynh Van Hien va Tir Thanh Truyen<br /> xa'u tfl cac vflng n u d i l a n c a n . (2006). Danh gia tae ddng ve mat xa hdi ciia cac hoat<br /> ddng nudi trdng thiiy sin man Ig ven bie'n Viet Nam.<br /> . (2) B a n h a n h t h e m cae c h i n h s a c h Tap chi Khoa hpc - Dai hoe Cin Tha, sd Dac biet, 2006,<br /> khuye'n khich p h a t t r i e n n g a n h h a n g t d m tr.220-234.<br /> sinh t h a i , d i u tfl p h a t t r i e n ddng bd cac (10) Pham Van Suy (2007). Khio sat tinh hinh khai<br /> p h a n doan cua ea n g a n h h a n g . thac va sir dung tdm sii bd me d tinh Ca Mau. Luan an<br /> td't nghiep cao hoe Nudi trdng thuy sin, Khoa Thiiy sin<br /> (3) T a n g cfldng t a p hua'n ky t h u a t t h e o<br /> - Dai hoc Can Tha.<br /> quy t r i n h tdm s i n h t h a i , ca s a n xua't gid'ng (11) Sinh, L. X. (2004). A bio-economic modeling<br /> va nudi. of shrimp hatcheries in the Mekong River Delta,<br /> (4) Khi t h u m u a t d m s i n h t h a i n e n Vietnam. PhD thesis. University of Sydney, Australia.<br /> m u a ca tdm cd kich ed nhd de g i a m t h i e t (12) Sd Thiiy sin Ca Mau (2005). Kei qui dieu tra<br /> ve tinh hinh nudi tdm a tinh Ca Mau.<br /> thdi cho ngfldi nudi.<br /> (13) Sd Thiiy sin Ca Mau (2007). Bao cao tdng ket<br /> (5) T a n g cfldng q u a n g b a thfldng h i e u hing nam.<br /> vk xuc tie'n thfldng m a i de md r d n g t h i (14) Thieu Lu (2004). Tmh hinh nudi tdm sinh thii<br /> trfldng chd cae s a n p h a m tdm s i n h t h a i . d ddng bang sdng Ciru Long. Tap chf Thiiy sin.<br /> <br /> <br /> <br /> <br /> Nghiin cuu Kinh ti s6 376 - Thing 9/2009 47<br />