KHOA HOC CONG NGHE
HIEIM TRAIMG K Y T H U A T V A G I A I P H A P P H A T TRiElV IXIGHE IVUOI IXIGAO G I A [Tapes canspersusii Q
HUYEIM VAIM O d l M , TilVH Q U A I V G IVIIMH
Thdi Thanh Binh^ Trin Ngoc Anh^
TOMTAT
Van Don la huyen dao cua tinh Quang Ninh c6 ti&m nang Ion ve nuoi nhuyfin the. Ngao gia hay con duoc gpi la ngao hai cui (Tapes conspersus Gmelm, 1791) la ddi tirong nuoi moi va co gia tri kinh te b huyen Van Don. Bai bao trinh bay ke't qua di^u tra hi^n trang ky thuat nuoi ngao gia tai huyen Van Don. Hau h^t cac ho nuoi cho rang chua co qui trinh cong nghe nuoi ngao gia duoc cong bd, cac ho nudi ngao chu yeu doa vao kinh nghiem va ky thuat nuoi tu hai de ap dung nuoi ngao gia. Ngao dupe nuoi trong long nhua hinh tron hoac bau due co chua cat xop. Cac long nudi ngao gia dupe dat a bai dirdi trieu, quanh cac dao. Dien tich trung binh mdi hp nuoi ngao gia la 2,0 ± 1,42 ha/hd voi 20.000-70.000 Idng/hp, m^t do nuoi 60-100 conAdng. Tren 96% gidng ngao b Van Ddn dupe nhap tir tinh Khanh Hda va Trung Qudc, voi co gidng tha 0,8-1,2 cm/con. Thoi gian nuoi 11-15 thang/vu, co thuong pham ngao gia 25-30 con/kg. Ty le sdng dat trung binh 61,02%. Ngao gia thuong pham chu yeu dupe ban cho Trung Qudc, mot phSn duoc tieu thu o thi trudng ndi dia. Nghien ciiu da d^ xuat mdt sd giai phap phat trien ngao gia a Van Ddn theo hudng bfin vimg.
Tii khda: A^so^/a, Van Bdn, ky thuat nuoi nhuySn the.
1 . OAT VAN BE
Van Ddn la huyen dao cua tinh Quang Ninh, co tiem nang phat trien nuoi trong thuy san bien bac nhat b mien Bdc niroc ta. Voi di§n tich tren 8.900 ha mat bien, co tren 200 hon dao Ion, nho trai dai gAn 50 km tir Bac xudng Nam, tao ra nhieu viing vinh kin, truong cat, bai nong... Van Don co dieu kien thuan loi cho phat trien nghe nu6i nhuyen th^ nhir hau Thai Binh Dirong, tu hai (UBND tinh Quang Ninh, 2016).
Tnroc day, phong trao nuoi tu hai a Van Don phat trien rat manh. Tuy nhi6n, tu nam 2011 den nay dich bfenh bung phat gay ra thiet hai Ion cho ba con ngu dan n6n tir nam 2013, ngiroi dan tu phat dich chuydn sang nuoi ngao gia hay con dugc ggi la con ngao hai cui (Hinh 1) thay th^ cho tu hai. Day dugc coi la nghe nuoi nhuyfen the moi mang lai loi nhuan cao.
^"f^i 2 3 4
^
Hinh 1. Ngao gid (Tapes conspersus Gme^, 1791) dugc nudi CT Van Don, tinh Quang Ninh
' Tmdng Cao ddng Kinh te Ky thuat va Thiiy san
^ Khoa Thtly san, Hpc vien Nong nghiep Viet Nam Email; [email protected]
Dien tich nuoi ngao gia tai huyen Van Don da len d^n hang tram ha voi 274 hp tham gia nu6i. Hien nay ngao gia co gia 65.000-80.000 dong/kg. Nghe nuoi ngao gia da giiip hang tram hp dan tai cac xa dao cua huyen Van D6n thoat ngheo va trCT nen giau cd voi miic thu nhap hang tram trieu dong, thim chi hang ty dong mdi nam (Phong NN&PTNT huyen Van Ddn, 2017). Tuy nhidn, cdng tac quan ly, chudn bi ddu tu cac ngudn luc can thiet chua theo kip tdc dp phat tnen cue ky nhanh chong dang day nghe nudi ngao gia cua huydn Van Ddn diing truoc nhi^u kho khan, thach thuc. Viec phat tridn qua 6 at ddi tupng nudi nay co the gay khd khan trong cdng tac quan ly dich benh, nguy co bimg no dai dich nhu da timg xay ra vdi ddi tupng nudi tu hai la khdng he nho. Tnidc tinh hinh do, vide nghien cuu danh gia mot each day dii, khoa hpc ve hien trang nhdm tim ra nhimg giai phap gdp phdn on dinh va phat tri^n ben vung ngh^
nudi ngao gia b Van Ddn ndi rieng va tinh Quang Ninh ndi chung la thirc su can thiet
2 . PHUONG PHAP NGHIEN CUU
Nghidn cuu dugc thuc hien trong nam 2018 nhdm dieu tra hien trang ky thu^t cua ngh^ nudi ngao gia tai huyen Van Don, tinh Quang Ninh. S6 lieu so cap ve hien trang nghd ngao gia dupe thu tir Sd Ndng nghiep va Phat trien ndng thdn (NN&PTNT) tinh Quang Ninh, Phdng NN&PTNT huyen Van Ddn. So lieu tiiii cap dugc thu thap thdng qua phuong phap danh gia nhanh ndng thdn (RRA)
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 4/2019 63
va phirong phap didu tra qua phieu (QS) (Groves va ctv., 2004).
Theo bao cao cua Phdng NN&PTNT huydn Van Don, toan huyen cd 274 hg nudi ngao gia thudc 5 dia diem: thi tran Cai Rdng, cac xa: Ddng Xa, Thdng Lgi, Ban Sen va Ngpc Vimg. Sd mlu dieu tra cho mdi vimg nudi trong nghien cuu nay duoc tinh toan theo cdng thiic cua Yamane (1967) vdi tong sd hd duoc dieu tra la 151/274 phan bd cho cac dia diem nhu sau: thi tran Cai Rdng (45/88), Ddng Xa (24/43), Thdng Lgi (35/63), Ban Sen (25/45) va Nggc Vimg (19/35). Nhimg thdng tm chinh dugc thu Hiap gdm:
Cac dung cu thidt bi nudi, tieu chi lira chon gidng tha, ky thuat cham sdc va quan ly, benh va phdng benh.
Sd lugng mdu dieu tra dugc tinh toan ngdu nhien bdng ham phan bd ngdu nhien Rand trong MS Excel 2010. Phuong phap thdng ke md ta dugc ap dung de xir ly sd heu ciia nghien ciiu tren phdn mdm MS Excel 2010.
3. KET QUA VA THAO LOAN
3.1. Hi6n trang nghe nudi ngao gia t2u huydn V^n Don
Kdt qua dieu tra ngau nhidn 151 hg nudi ngao gia nam 2018 cho thdy, 100% cac hd dugc dieu ra cho rdng chira duoc tap huan hoac chuyen giao cdng nghe nudi ngao gia. Nghe nudi ngao d Van Don la do ngudi dan tu phat, ky thuat nudi chu yeu dua vao kinh nghiem nudi tu hai cua cac nam trude day de ap dung cho nudi ngao gia.
3.1.1. Didn ti'ch va chon bai nudi
Bang 1. Di^n tich tnmg hinh nudi ngao gia ciia cac ho CT Van Ddn
STT
1 2 3 4
^
Xa/Thitran
Cai Rong DongXa Thing Lai Ban Sen Ngoc Vimg Tong cong:
So ho nuoi 88 43 63 45 35 274
Dien tich (ha) 248,3
91 97,2 96,5 47,4 580,4
Tmng binh (ha)
2,8 2,1 1,5 2,1 1,4 2 ±1,42 Ghi chu: * do lech chuan
Ngao gia duoc nuoi trong long nhtra va dat a vimg duoi triSu. Bai triiu de dat 16ng nuoi thuong cb nen day la cat btm va bang phang, it sijt liin ngap nuoc quanh nam va co the dat sau 4-5 m, khi thuy tiieu thSp nhJt do sau muc nuoc noi nuoi ngao gia vin Ion hon 0,5 m, do man dao dong 20-31%o, tdc do dong chay 0,1-3 m / s .
Tong dien tich nudi ngao gia tai huyen ^ ^ ^™
la 581,4 ha (Phong NN&PTNT huyen Van B6n, 2017). Tinh chung toan huy6n, qui m6 nuoi ngao gia trung binh ciia cac ho la 2,0 ± 1,42 ha/ho. Cac h6 6 thi tran Cai Rong nuoi difin Hch Ion nhat trung binh la 2,8 ha/ho va cac ho b xa Ngoc Vimg nuoi voi qui mo trung binh thap nhat la 1,4 h a / h o (Bang 1).
3.1.2. Chuan bildngnudi
Long nuoi ngao gia duoc lam bang nhija co d^g hinh bau due (dai x rong x cao = 50 x 35 x 27 cm) co luoi lot day Idng hoac hinh tron (duong kinh x chiAi cao = 40 X 27 cm); long tron khong can luoi lot Long ban due va 16ng tron deu cb nap luoi day ra$t long.
Cac long nhija nay do chieu cao thap hon long nuoi tu hai thuong pham 3 cm (Thieu Van Thanh, 2013).
3.1.3. Nguon gidng va tha gidng
Theo thong ke cua Phong NN&PTNT huyh Van Don (2017), nhu cau con giong ngao gia ngay cang tang cao, dao dong 1-1,3 ty con giong/nam. Tuy nhien d huyen Van Don chi co mot trai giong a xa Thang Loi cb cbng suat 3-5 tneu con gib'ng/nani nhung nam 2018 da khong san xuat Tren dia ban Quang Ninh con cb Co sb II ciia Truong Cao dang Kinh td, Ky thuat va Thuy san san xuat 5-7 tridu con gidng/nam. Do dd gidng ngao gia chii yeu nhap tu cac trai gidng d Nha Trang (Khanh Hda) va Trung Qudc. Dieu dang chii y la nhidu hd nudi ngao chua quan tam den chat lugng con gidng, cd tdi 81,591 ho nudi khong kiem tra benh ngao gia gidng truoc khi tha. Trong sd 18,5% sd ho cd kiem tra chat lupng gidng. nhung cac phuong phap kiem tra chi bang cam quan, dua tren kinh nghiem ban than,... Do do, chat luong ngao gia gidng khdng duoc danh gia day du, nhat la trong cac trudng hop cam nhidm cac tac nhan vi n i t vi khuan, nam va ky sinh frung.
Miia vu tha gidng ngao gia a Van Ddn thuong bat diu hi thang 5 - 9 hang nam. Kdt qua didu tra cho thay thdi gian nuoi ngao gia 10-15 thang/vu, himg binh la 12,4 thang/vu. Dia phuong cd thdi gian nuoi ngao gia dai ngay nhat la xa Thang Loi (15 thang/vu), ngan nhat la xa Dong Xa (10 thang/vu) (Bang 2).
Ngao gidng tha la gidng cip II, lach cb djng iki dao dong 0,8-1,2 cm. Gidng cd mau sic tuoi sang diic tnmg cho loai. Cach kiem tra con gidng i^^^^ ^ ^ la tha con gidng vao chau nuoc sau 2-3 pjj^^ , ,. ' , hoat dong md mieng va thd vbi hiit ra npf.. , , ling vbi nhanh nhanh nhen vdi tieng (J6n„,, ^'' "
thanh dungcu chua. ^^&vit,
64 NONG NGHl|P VA PHAT TRIEN NONG THON - KY 1 - THAN(5
KHOA HOC CONG NGHE
Cac hd thudng xiic cat vao long nudi vdi do day 18-20 cm, che luoi mat long nudi va chuydn long nudi xep trdn be cdng tac. Keo be cdng tac ra vi tri tha Idng. Gidng ngao gia dua ve duoc h-eo bang long nudi trdn be cdng tac. Diing chen nho miic gidng tha va rac d6u trdn mat long nudi hoac de giiia long theo mat dp da xac dinh (80-100 con/long bau due va 60- 70 con/long trdn). Long dugc dua xudng day bai nudi bang each dung day treo cd mdc sat mSc vao 2 ben sudn long va dua tir tir l6ng xuong day hai nudi.
Ngudi lan dudi day bai do va dat l6ng thanh hang duoi day bai nudi.
Ket qua di^u tra cho thay cd 93,4% hd nudi tra loi chua quan tam den sd luong long dat nudi/ha, sd luong Idng nudi chu yeu dua vao kha nang tai chinh dau tu nudi ngao cua timg hd. Cac hd cho biet nhirng nam dSu tha ngao gia chi sau tir 10-11 thang ngao dat CCT thuong pham va cd the thu hoach nhung hien nay thdi gian nudi phai keo dai hon mdi dat duoc CCT thuCTng pham. Didu nay cd the la he luy cua viec phat trien nudi ngao gia bimg phat CT Van Ddn lam mdi trudng thay doi, thiic an trong viing nudi cho ngao gia hi giam manh dSn den ngao cham Idn nen thdi gian nudi phai keo dai.
Bang 2. Hi^o trang ky thuat nudi ngao gii a huydn Van Don nSm 2018 Cic chi tieu
Kinh nghiem nudi (nam) Dien tich nudi (ha/hd) Kich cb gidng (con/kg) Mat dd (con/ Idng) Sd long nudi (Idng/hb) Thdi gian nudi (thang) Cd ngao thu hoach (con/kg) Nang suit (kg/ldng/vu) Tile sdng (%) San luong (tin/hd/vu)
Nho nhit 2 0,3 2.500
60 20.000
10 25 1,3 57,4 38,8
Ldnnhat 5 9 3.000
100 70.000
15 30 2,4 75,1 135,8
Trung binh + SD 2,43 ± 0,3 2,0 ±1,42 2.731 + 327
72 44.000 12,36 + 1,22
27 ±1,04 1,94 61,02 85,36 Kdt qua dieu tra cho thay, mat do nudi ngao gia
igiao ddng 60-100 con/long, trung binh la 72 con/long va mdi vu cac hd nudi 2 -7 van long (trung binh 4,4 van Idng/hd), tuong duong 18.107 Idng/ha.
Dia phirong cd cac hd nudi Idn nhat la thi tran Cai Rdng, tiep den la xa Ddng Xa va thap nhat la xa Ban Sen.
3.1.4. Cham sdc va quan ly
Do ngao gia la ddi tugng an loc, ky thuat nudi kha don gian, hau nhu chua diay bdnh dich xuat hien b Van Ddn. Tuy nhien ngao gia duoc nudi trong he thdng ho, viec ap dung cac bien phap quan ly, cham sdc nham nang cao ty le sdng, tdc dp tang trudng va giam thi^u kha nang mdc benh dich gap nhieu khd khan. Nguy coxay ra dich benh nhu tu hai rat cao.
Ket qua dieu tra cho thay, cac hd nudi ngao gia co hieu qua (81,5% tra loi) da su dung cac bien phap quan ly, cham sdc ddi vdi ngao gia chu yeu: Lira chgn dia diem nudi phti hop; ve sinh, dgn sach cd rac, rong tap; lua chgn con gidng dam hao tidu chuan; mau sdc tuCTi sang tir nhien, kich cd ddng deu, khde manh, vo khdng dgp vd, ty le di hinh thap, xuat xu ngudn gdc rd rang; tha gidng dung thdi vu; thudng xuyen kiem
tra ngao gia nudi, dac biet truoc va sau nhimg bien ddi bat thudng cua thdi tidt (mua bao, nang ndng keo dai....); dinh ky kiem tra tdc do Idn ciia ngao gia;
thudng xuyen kiem tra long, ludi, be nudi, hd thdng phao ndi, neo be... de kip thdi sua chfta, thay the;
lam tdt cdng tac trdng coi, bao ve nhat la thdi didm ngao gia sap den ky thu hoach va dam bao an toan cho Idng, be.
Tuy nhien, mdt sd hd dan (18,5%) do didm nudi lua chon khdng dam bao kin gio, trude nhung ky bao Idn thudng di chuyen be nudi den noi an toan. Vdi hinh thiic nudi Idng dat bai, nhirng hd nudi it, cd the dl chuyen nhimg Idng dat phia tren cao xudng noi thap hon de tranh anh hudng ciia nirdc mua. Nhirng hd nudi ngao gia cd hieu qua thap do tha gidng kem chat luong (10,6%), it kiem tra va ve sinh long nudi (7,9%).
3.1.5. Thu hoach
Sau 10-15 thang nudi ngao gia dat cd 25-30 con/kg (30-40 g/con) cd the thu hoach. Nang suat dat 1,3-2,4 kg/ldng, trung binh dat 1,94 kg/long, tuong duong 42,7 tan/ha. Nang suat ngao gia cao hon nhieu lan so vdi ngao Ben Tre. Theo Bui Ddc
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 4/2019 6S
Thuyet va Trin Van DOng (2013), nang suit nudi ngao Ben Tre a tinh Quang Ninh chi dat 0,6±1,1 tan/ha.
Theo k i t qua didu tra ty le sdng cua ngao gia nudi thuong phim dao ddng 57,4 - 75,1% Tuy nhien theo ngudi nudi ngao gia cho biet ty le sdng cua ngao gia ngay cang giam do chit luong gidng kem, khdng duoc kiem soat mdi trudng ngay cang d nhiem va do led nhuan cao nen sd hd nudi ngao ngay cang tang.
3.1.6. So-bd danh gia hieu qui nudi ngao gii T i t ca nhirng ngudi dan duoc hbi deu tra loi nudi ngao gia cd lai va lai cao hem nhidu nghd khac. Hach toan cho 1 ha nudi ngao gia duoc trinh bay d bang 3 va hinh 2.
Tdng chi phi cho 1 ha nudi ngao gia la 1.325.765.250 ddng trong dd chi phi Idn nhit la ngao gidng chiem 48% hep den la chi phi mua Idng nudi la 21%. Cac chi phi khac bao gdm thue thuydn, tho Ian va lai suit ngan hang la 10%. Tdng doanh thu cho md hinh nudi 01 ha ngao gia la 2.508.000.000 ddng va loi nhuan
a 4 7 , * M 1.182.234.750 ddng, tysuatloi nhuank
Nghd nuoi nhuydn the khong can Huynh chi phi gidng Ion nhat Theo nghien ciW ^,^ ^ Van Hien va Le Xuan Sinh (2014) chi pta ^° °^ ^ ha nudi ngao Ben Tre (Meretnx lyratu) " _ chidm 80% tdng chi phi, nhung chi thu lai " m » ddngAa/vu/cosdsan xuat Le Van Khdi vaU; i n m l Ghi (2015) cung cbng bd, chi pW con giong chiem 30 2% - 49,5% tdng chi phi khi nubi ngao Ben Tre trong ao d i t Ddi vdi nudi ngao gia, tdng thu la 198,4
± 19 1 Weu ddng/ha/vu. Loi nhuan trung binh cm cac hd nudi la 94,8 ± 16,0 tridu ddng/ha/vu. Nhuv9 so vbi nudi ngao Bdn Tre thi nudi ngao gia cho hi?u qua kinhte cao hon.
Theo Thieu Van Thanh (2013) loi nhuan nudi in hai thuong phim d hinh thiic nubi bai la 62% va nuS trong long la 65%, cho thiy loi nhuan cao hon nudi ngao gia Tuy nhien nhOng nam gan day nghd nudi tu hi kem phat tnen do dich benh xay ra thudng xuyen. Cac ho nudi m hai tnidc day d Van Ddn ddu da chuyen sanj nudi ngao gia.
Bang 3. Hach t o ^ cho Cac khoan chi va thu AKhoan chi Ldng nudi (khau hao 50%) Cat
Ngao gidng Nhan cdng Chi khac B. Khoan thu Ngao gia Loi nhuan (A-B) Ty suit loi nhuan
md hinh mdt ha nudi ngao gia 6 huydl Don vi tinh
Chiec m=
Con Cdng Chuyen
Kg
%
Sdluong
22.000 550 1.584.000 780 10
41.800 Don gia
(ddng)
26.000 150.000 400 300.000 2.000.000
60.000 VtoDdn
Thanh tidn (ddng) 1.325.765.250
286.000.000 41.250.000 633.600.000 234.000.000 130.915.250 2.508.000.000 2.508.000.000 1.182.234.750 47,1
Hinh 2. Co ciu chi phi san xuit trong nudi ngao gii d huy^n van Ddn
3.2. Nhiing thuan Xiji v i khd k h i n ciia ngh^ nufii ngao gia o huydn Van Ddn
Nghd nudi ngao gia a Van Ddn dupe phat tri^
trong vong 5 nam gan day cd nhiing thuan loi chinli la thien nhien uu dai cho Van Ddn cd didn tich mSl bidn Idn, dieu kien mdi tnidng giau dinh duong thuan loi cho phat trien nudi ngao gia. Dien tich mil nude nudi hiu nhu chua phai tra phi (96,7%). NuS ngao gia khdng phai cho an, ngudi lao ddng chu y^
tha gidng va trong coi nen ky thuat nudi don gian (97,4%), Gia ngao tuong ddi dn dinh so vbi cac mlt hang thuy san khac (55%). Tinh hinh an ninh d vimg nudi tuong ddi tdt, chua co hien tuong tron, ngao gia
KHOA HOC CONG NGHE ciia ngiidi nudi (90,7%) (Bang 4). Tuy nhien nghd
nudi ngao gia d huyen Van Don cdn gap phai mot sd khd khan: Ngudn gidng chu yeu nhap hi dia phuong khac nen bi ddng va khdng kiem soat duoc chat Immg (84,1%); von cho san xuat chua chu dong (68,2%); do la loai thiiy san mdi, thi trudng tieu thu ngao gia con han che (88,1%). Ngao gia hidn nay chu ydu tieu thu CT dang ngao tuoi sdng va tap trung d thi trudng Trung Quoc, mdt phan tieu thu trong nude.
Ngoai ra, ngudi nudi cdn nhan thay nghe nudi ngao gia cdn gap cac khd khan khac nhu: Cat xdp dimg cho nudi ngao gia ngay cang khan hiem; mat dp nudi ngao ngay cang day lam ngao cham Idn; cd su tranh chap vimg nudi; nguy CCT xay ra dich benh giong nhu nghe nudi tu hai trude day cao; thi trudng Trung Qudc ddi hdi chat che hon ve truy xuat ngudn gdc san pham (40,4%).
B ^ 4. Nhiing 1hu|ln loi va khd khan trong ngh^
nudi ngao gi& a huyfen Van Bdn Cac ydu td
Thu$n 10 ciia nghS nudi ngao gia
Didn tich mat nude khdng phai tra phi
Ky thuat don gian it tdn cbng cham sdc
Gia ca dn dinh Tinh hinh an ninh tdt Thuan loi khac Khd khan ctia ngh4 nudi ngao gia
Ngudn gidng bi ddng, chit luong khd kiem soat Von chua chu ddng Thi trudng tieu thu cdn han che
Khd khan khac
Sd ho
102 147 83 137 52
127 103 133 61
Tyle
(%)
67,5 97,4 55,0 90,7 34,4
84,1 68,2 88,1 40,4 3.3. Mot so giai phdp phap triln ngh^ nudi ngao gid theo hudng b^n vflng tai huy^n Van Don
D^ ngh^ nudi tu hai cua huyen Van Don phat trien theo hudng ben vung can thuc hien ddng bd cac giai phap nhu: Tinh Quang Ninh can co quy hoach viing nudi ngao gia an toan, trong dd can chu trong danh gia siic tai mdi trudng de phat trien viing nudi an toan, bdn vimg; xay dung cac md hinh san
xuat ngao gia theo chudi; nghien cuu va ban hanh qui trinh cdng nghe nudi ngao gia; xay dung trai san xuat gidng cung cap gidng cd chat lupng tdt, gia thanh ha cho ngudi nudi; lua chon mua vu tha gidng thich hgp va kich cd ngao gidng phii hgp de ngao gia cd the thich nghi phat trien tdt, khdng nen nudi ngao vdi mat do qua day (mat do phii hop <70 con/ldng);
dinh ky ve sinh ldng nudi. Tang cudng quan trac canh bao mdi trudng viing nudi de tranh cac didn bidn xau ciia mdi trudng nudi; nghien cuu cac san pham che bien tir ngao gia; xay dung thuong hieu ngao gia va tang cudng quang ba san pham cua dia phuong.
Qua dieu tra 151/274 hd nudi ngao CT huyen Van Ddn cho thay 97,8% cac hd nudi nay van tiep tuc dau tu de md- rgng nudi ngao gia tai dia phuong trong cac nam tiep theo. Do do cac co quan quan ly nha nude can cd bien phap hd trg' kip thdi de nghe nudi ngao gia CT huyen Van Ddn phat trien ben vimg.
4. KET LUAN
Huyen Van Don cd nhieu tiem nang lgi th^ de phat tnen nghe san xuat ngao gia. Nghe nudi ngao gia la mdt hudng phat trien kinh te thuy san manh cua tinh.
Ngao gia dupe nudi trong long nhua cd chiia cat xdp, ngudn gidng chii yeu nhap tir ngoai tinh, mat dp giong tha 60-100 con/ldng, miia vu tha gidng tir thang 5 den thang 9. Thdi gian nudi 10-15 thang/vu, CCT ngao thu hoach 25-30 con/kg, nang suat trung binh dat 42,7 tan/ha, Ipi nhuan trung binh dat la 47,1%. Tuy nhien phat trien nghe nudi ngao gia tai Van Ddn cdn mang tinh tu phat, thieu tinh bdn viing, phat tri^n chua tuong xung vdi tiem nang lgi the sin cd.
Trong thdl gian tdi de nghd san xuat ngao gia tai Van Don phat tridn manh va ben viing, tinh Quang Ninh c^n thuc hien ddng bd cac giai phap: Tang cudng tuyen truyen nang cao nhan thiic cdng ddng;
dau tu hop ly cho nghien cuu ap dung cac tien bd khoa hoc ky thuat; ra soat, didu chinh day manh cdng tac quy hoach va quan ly vimg nudi an toan.
Thuc hien dang ky gidng moi vdi ddi tugng ngao gia, xay dung cac md hinh san xuat theo chudi gia tri.
l / n C A M O N
Tac gia xin tran trong cam on Chi cue Thuy san Quang Nmh, Phdng NN&PTNT huyen Van Don da cung tap cac so hdu; cam on Khoa Thuy san - Hoc
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 4/2019 67
(Luti-aria rhyncaena) tai huyen Vao Ddn, tinh Quang Ninh. Luan van Thac si. Dai hpc Nha Trang. 58 trang.
6. Bin Dac Thuyet, Trin Van Dung (2013). Hi?n trang nghe nudi ngao CT mot so tinh ven bien mien Bac va Bac Trung bd, Viet Nam. Tap chi Khoa hoc va Phat tridn, Tap 1 (so 7): trang 972- 980.www.hua.edu .vn
7. UBND tinh Quang Nmh (2016), Quyet dinh so 4209/QD-UBND cua UBND tinh Quang Ninh vd phe duydt quy hoach phat trien nganh thuy san tinh Quang Ninh den nam 2020, tAm nhin den nam 2030, ngay 15 thang 12 nam 2016.
8. UBND huyen Van Ddn (2016). Bao cao Qui hoach phat trien nudi trdng thuy san huyen Van Ddn giai doan 2020-2030.
9. UBND huyen Van Ddn (2018). Bao cao sd 55/BC-NNPTNN cua Phdng NN&PTNT huyen Van Ddn ve ket qua hien khai thuc hien Nghi quyet sd 05-NQ/TW ngay 01/11/2016 cua Ban Chap hanh Trung uong Dang, ngay 31 thang 05 nam 2018.
10. Yamane T (1967). Statistics: An inh-oductory Analysis. 2nd edition. Harper & Row. New York, pp vien Ndng nghiep Viet Nam, Ihac si Ha Van Nmh -
Hoi Ndng dan huyen Van Ddn da ho tro va giup dd trong qua trinh thuc hien nghien cuu.
TAI UEU THAM KHAO
1. Groves, R, F. Fowler, M. Couper, J.
Lepkowski, E. Singer vaR. Tourangeau (2004).
Survey Methodology. Wiley Series in Survey Methodology.
2. Huynh Van Hien va Le Xuan Sinh (2014).
Phan phdi lgi ich va chi phi trong chudi gia tri ngheu trang (Meretrix lyrata Sowerby, 1851) d tinh Tra Vinh. Bai viet tham gia Hdi thao moi lien he giiia rimg ngap man va ngudn Ipi ngheu, ngay 18/11/2014, thanh phd Hd Chi Minh. Vien Sinh hpc nhiet ddi. Thanh phd Ho Chi Minh, trang 110-120.
3. Le Van Khdi va Le Thanh Ghi, 2015. Anh hudng cua mat do den sinh trudng, ty le sdng, nang suat va hieu qua kinh te cua ngheu (Meretrix lyratd) nudi thuong pham trong ao dat. Tap chi Khoa hgc va Phat tnen, Trudng Dai hoc Ndng nghiep Ha Ndi.
13(2): trang 192-199.
4. Phdng Ndng nghidp va Phat tridn ndng thdn huyen Van Ddn (2017). Bao cao thdng ke ndng nghidp nam 2017. 4 trang. 886 - 887.
5. Thieu Van Thanh (2013). Nghien ciiu hien trang va d^ xuat gmi phap phat trien nghd nudi tu hai
TECHNICAL STATUS AND THE SOLUTION OF DEVELOPMENT FORTURGID CLAM (T^ies conspersus) FARMING IN VAN DON DISTRICT, QUANG NINH PROVINCE
Thai Thanh Binh, Tran Ngoc Anh Summary
Van Don is an island district of Quang Nmh province with great potential for mollusc culture. Turgid clam or called "Ngao hai cui" {Tapes conspei^usGmehn, 1791) is new aquaculture and highly value species in Van Don district. This paper presents the results of survey on tiie current status of Turgid calm culture techniques in Van Don districi. Almost of farmers claimed that there was no published technology for Turgid calm culture. Farmers mainly relied on expenences and techniques of raising Otter snub clam to apply for Turgid clam farming. Turgid clam was raised in a round or oval plastic cage contaming porous sand. The Turgid clam cages were placed in low tidal around the islands. The average area of each household involved in Turgid clam culture was 2,0 ± 1.42 ha/household with from 20.000 - 70.000 cages/household, die stocking density was from 60-100 seed/cage. Over 96% of the Turgid clam seed in Van Don were imported from Khanh Hoa province and China with the seed size of about 0.8-1.2 cm/individual. Time for cultunng Turgid calm was from 11 to 15 months/crop, market size of clam is from 25-30 individual/kg. Average of survival rate was about 61.02%. The major market of Turgid clam is China, while domestic market i,s partly consumption. The study has proposed a number of solutions to develoo sustainably Turgid clam farming in Van Don dictrisct.
Tir khda: Turgid clam. Van Don, Mollucs raising techniques.
NguCTi phan bidn: TS. Biii Th^ Anh Ngay nhan bai: 01/02/2019 Ngay thdng qua phan bidn: 4/3/2019 Ngay duydt dang: 11/3/2019
