Tgp chi Khoa hoc - Cong nghe Thiiy sdn So 3/2013
• V A N DE TRAO DO\
IfNG DUNG RAN NHAN TAO TRONG VIEC BAO VE VA PHAT TRIEN NGUON LOI THUY SAN
THE APPLICATION OF ARTIFICIAL REEFS TO MARINE RESOURCES PROTECTION
Ngiy nhan bai: 27/10/2012; Ngay phan biea thong qua- 07/5/2013; Ngay duyet di
Nguyen Trong Luvng'
;: 10/9/2013
TOIW TAT
Cdng nghg rgn nhdn tgo Id mgt tmng nhimg gidi phdp 1^ thugt dupc cdc naac cd bien tren the gidi dp dung di bdo ve vd phdt tnen nguon Ipi thiiy sdn, phuc vu phdt tnen nghe cd iheo hirdng on dfnh vd ben vimg. Ngdy nay, cong nghi ndy dang dupc dp dting rgng rdi trin cdc Chdu luc cd vi quy md vd ky thudt, mang Igi higu qud cao trong viec phdt trien nghe cd
Vdi muc dich chia se thdng tin, ndng cao nhdn thdc vd hinh thdnh y thuc ve bdo ve vd phdt triin nguon lpi th^ sdn cda bgn dgc, bdi viet dd cung cdp mot so thong tin ca bdn ve tinh hinh nghien cuu, ung dyng vd ddnh gid ran nhdn tgo tren the gidi
Tir khda: Rgn nhdn tgo. nguon lai thuy sdn ABSTRACT
Artificial reef technology is applied in developed countries to protect and regenerate the marine resources for sustainable fishenes development.
Nowadays, this technology is applying in almost continents and achieved high effect in fisheries development. In order to share the information and improving aware of fishenes, aquatic resources protection, the paper provides some information about research, apply and evaluate the artificial reef in the world.
Keywords Artificial reef, fishenes resources
IMtfOAU
Qua qud tiinh phdt biln, tiiyc tien nghe khai tiiac thOy sdn d Vigt Nam cung nhu ti-en thd gidi dd hoan todn bde bd quan nigm ti> tdu cho ring "ngudn tgi thuy sdn Id vd tdn va dgi dugng ta rat hdo phdng" [1].
Khi eudng lyc khai thdc phdt tiien mgnh va trinh dp cong ngh§ dgt tdi mirc kha hien dgi thi hau hit cae lodi tiiuy san ti^n cde dgi duong dil song d gan bd hay xa bd, tang mgt. tang giira hay tang day vd tiiam chf la sing tiong bim. hang da vd dang bj con ngudi ddnh bit kha tiigt d l . Han nira, khai thdc hai san qud mdc bdng nhirng phuong phap ddnh bit mang tfnh huy diet khdng nhirng pha va cdn bang sinh thai md edn hiiy hogi noi cu tni cua cac lodi thiiy san. Idm gidm khd ndng bo sung nguon Igi ty nhien vd hdu qua cda nd td gidm trir lugng cd khai Uiac.
De hgn c h l sy tae ddng cua con ngudi len nguon tgi smh vat bien ndi chung va nguon tgi thuy sdn ndi rieng. cdc nude tren t h i gidi da ap dung dong tiidi nhilu giai phdp khdc nhau. Trong dd. ran nhdn tgo td giai phdp ky thugt dugc cdc nhd khoa hoc vd qugn ty danh gia rat cao trong viee bao ve. tai tao vd phdt triln nguon Igi thuy san.
Trdn t h i gidi. tiiuat ngir rgn nhan tao (Artificial Reef) da dugc su' dgng kha p h i bien. Khdi nidm ndy dugc sir dyng khae nhau Uieo tung quoc gia. vimg lanh tho vd myc dich tgo rgn. Trong ITnh vyc bao vg vd phdt triln nguon Igi. rgn nhdn tgo dugc hieu Id vi^c xdy dyng "ngoi nha" eho ed bang nhirng vdt the ty nhien hoge do con ngudi tgo ra va tha xuong ddy biln nham thay d l i dieu kien vat ly, hai duong, tgo ngi dinh dudng cu, tgp trung cd vd tgo gia till d l
' ThS. NguySn Trpng Li«mg: Vl$n Khoa hoc va C6ng ngh# khai thdc thiiy sdn - Tnrtmg Oai hpe Nha Trang
Tgp chi Khoa hQc - Cong nghe ThOy sdn So 3/2013
khdi phgc san hd nham ndng cao hifu qud khai thdcd vimg nude xa bd vd hgn c h l cudng tue khai thae d vung nude ven bd.
n. NQI DUNG 1. Lich sip phat t r i l n
Vi§c thd ran nhdn tgo trdn the gidi dugc tiln hanh tir r i t sdm vdi nhieu mgc dich khdc nhau. Tir hang ngdn nam trudc. lodi ngudi da biet sir dyng rgn nhdn tgo trong viec tri thiiy va chdng giae ngoai xdm. Xay dyng rgn nhan tao nhim phdt tnen nguon tgi thuy sdn dugc b i t d i u tir nhung nam 1600 tai Nhat Bdn. Vdo thdi gian do. ngudi Nhgt Bdn da xdy dyng rgn san hd nhdn tgo bang eao su vd dd tdng d l tring tao be. Ngudi ta nhgn thay rang, ben egnh tao bg phat tnln thi mat do cd d vung thd ran tang ten theo thdi gian vd ddy cung Id nIn tdng cho vigc phdt trign rgn nhdn tgo de tgp trong, bdo ve vd phdt triln ngudn lgi thiiy san. Viec nghien cuu, ung dyng ran nhdn tgo dugc phdt tnln manh me tir nhij'ng ndm 1970. den nay dd cd g i n 50 quoe gia va viing lanh tho tren the gidi ung dung cdng ngh^ ndy d l bao vd. tdi tgo. phdt triln nguIn lgi thiiy sdn vd hgn chl khai thde thdy san bat hgp phap.
D i n nay. cdc nhd khoa hpe tren t h i gldl da t l chirc dugc 9 lan Hpi nghj qudc t l v l rgn nhdn tgo vd mdi tnrdng song ciia cdc loai thuy sinh (International Conference on Artificial Reefs and Related Aquatic Habitats - vilt t i t id CARAH). Tgi Hpi ngh[ tin thu Nhat (1974) t l chire tgi Houston - Texas - Hoa Ky chi cd 35 bai tham ludn vd d i n Hgi nghj Iln thir Chfn (2011) tai Curitiba - PR - Brazil cd tdi 160 bdi tham tuan. d HOi nghj quoc te tan thir Bay (1999) cde nhd khoa hoc da tong kit. Hi#n tgi.
bdn t h i gidi chua cd mpt cdng trinh ndo tong hgp hay ghi ehdp tgi day dii ljch sir nghien euu va dng dung edng nghe rgn nhdn tgo trong vige khdi phye mdi trudng vd nguIn tgi thiiy sinh. Tgi Hdi nghj nay.
cd 19 quoc gia vdi 116 bai tham tudn Trong do, cd 25% s6 bdi bdo cdo v l nghidn cdu va thir nghi#m rgn nhdn tgo; 37% s6 bai bdo cao v l v i n de sir dyng rgn nhdn tgo; 30% bdo edo vilt ve ke hoach.
chinh sdch vd chuong trinh sir dyng rgn nhdn tgo vd s6 cdn tgi ehi thao ludn v l mge dich. y nghTa cua rgn nhdn tgo. Tuy nhien. d i n Hgi nghj tan thir Chfn da ed nhilu quie gia bdo cdo v l chuong trinh, chinh sdch vd ke hogch dng dyng rgn nhan tao. Ben cgnh dd, cde nhd khoa hgc eung da xult bdn cdc tdi ligu hudng d i n ky thuft xdy dyng rgn tgo phu hgp vdi cdc viing bien khdc nhau, hudng ddn tya chgn v$t ti$u tgo rgn, c l u tnic rgn, d|a dilm lap dgt....
O nude ta. cdc nhd khoa hgc chi mdi nghien cd'u irng dyng gid t h i rgn nhdn tao (be tdng cdt thep vd nhua PVC) de khdi phye rgn san hd tu nhidn md ehua quan tam den vige viee bao vg, tdi tao, phdt trien nguon lai thtiy sdn va ehong ddnh bdt bat hgp phdp. D I phat tnln nghe khai thdc thuy san theo hudng bin vung, ngodi cdc bien phdp dd vd dang thye hign nhu hign nay. ngdnh thuy sdn can triln khai nghien ciru, thir nghiem va ung dyng cdng nghg ran nhan tgo vao ITnh vyc bdo ve vd phdt triln nguon tgi thuy san, dgc bidt td a viing bien ven bd 2. LTng dung cong nghe rgn nhan tao 6 mgt s l nipd-c d i l n hinh
2.1. O Nhat Ban
Nhat Ban id mdt trong nhung cudng quoc tren t h i gidi ve cdng nghg ran nhan tao. De ndng cao vj t h i cua nghe cd thuang mgi. nude ndy da nghien ciru va irng dyng rgn tgo tu the ky thir 18. Rgn nhan tgo dugc xay dyng eho cd viing ven bd vd viing biln khai.
& vimg biln ven bd, rgn nhdn tao duge sir dyng d l phat tnln nguIn lgi hdi san nhd. ca chua trudng thdnh thdng qua cdi thign chit tugng mdi trudng nude vd han ehe edc nghe ddnh b i t mang tfnh huy diet cao nhu nghi te, ludi keo, tudi vay
Trong nhung nam gan ddy, Nhdt Ban da dau tu hdng chye t^ Yen eho vigc nghien ciru, thilt k l vd ung dyng cdng nghg rgn nhan tgo phye vy phat tiiln nghe ea. Tu nam 1976 din 2000. Nhat Bdn da dau tir 11.8601^ Yen de xdy dyng vd l i p dgt 644 rgn nhdn tao vdi quy md khoang 5 trigu m^, bao phu tren 12% dien tich day bien d vimg nude ven bd.
Ngodi viec bdo vg vd phat trien ngudn lgi hai san ven bd. hp edn tap trung cde dan cd dgi duang vdo vung nude ven bd nhim ndng cao higu qua danh b i t eho ede tau thuyin nhd.
2.2. O Th6 NhT Ky
Theo ghi nhdn ciia Khoa Thiiy sdn (Tardng figl hge Aegean, Tho NhT Kj") chuong trinh nghien cuu irng dyng rgn nhan tgo dau tien cua nude ndy duge bit diu tir nam 1989. Do sy phdt triln nhanh chdng ciia nghe khai thdc thiiy san, dac bigt Id nghi ludi keo day da Idm cho cac he smh thdi bien bi tan pha nghidm trgng vd nguIn Igi bj giam sOt nhanh chdng nSn da de dga den sy phdt triln ben vung ciia nghe ca nude ndy. Chfnh vi the. Chfnh phii nude nay da trien khai dong bg nhieu giai phdp ky thugt nham hudng tdi sy phat tnln bin vung eiia nghe khai thdc thuy san. Vdi chuang trinh phdt triln nghi cd ven bd, eai thien chat iugng mdi trudng sing cho cde lodi thuy sinh, ngan cdn nghi tudi keo
TRUONG OAI HOC NHA TRANG • 191
Tgp chi Khoa hoc - Cong nghe Thuy s, So 3/2013
hogt dgng bat hgp phap. bdo vd bai de ciia ca, phattrien du Ijch Ign bien vd bao vg nghe khai thae quy md nhd ven bd hp da xdy dyng 08 viing rgn nhdn tao vdi dign tieh khoang 1.500m^. Sau 8 nam thye hien, ket qua dgt dugc td thanh phan lodi ca d vung ran nhdn tgo tang ten khodng tren 40%, mdi trudng song dugc cdi thien va sinh k l ciia ngu ddn ngheo ven biln dugc on djnh [5]
2.3. (JAnh
Quoe gia ndy da xdy dyng ran nhdn tgo ti> nam 1984. d i n nay da tip dgt khoang 35.000 dgn vj rgn.
ehia tiidnh 6 viing rgn a vung bien ven bd. Mgc tidu ciia dy an xdy dyng rgn nhdn tao tdp trung vdo 5 rrnh vyc ehfnh: (1) Tgo dilu kign d l phat tiien du ijch
tan biln; (2) Khdi phgc lgi mdi tn/gng sing cua cac toai thuy sdn; (3) Phat tiiln kinh te - xd hdi cua cdng dong ngu ddn ven biln; (4) Gidm xung d^t cdc hogt ddng tidn quan den biln vd (5) phdt tiien ngudn \(fi thiiy sdn cho nghe cd thuang mgi.
Vi#c xdy dyng ran nhan tgo khdng nhirng Idm tdng ddng ke ngudn lai cd Tuylt, ldm Hum, cd Hing, cd Mu vd cdc toai nhuyen the d Vjnh Poole, Tomess vd Loch tjnne ma cdn tdi sir dgng vd giai tda sue ep cac logi phi tigu tren bd nhu lop xe cu, xi tiian h> nha may nhigt dien. Doi vdi qu6c gia ndy, cae chucmg tiinh, dy an xay dyng rgn nhdn tgo phuc vy nghi ca chu y l u dugc tai trg t)di cde t l chirc phi ehinh phu, chinh quyln dja phugng ven bien vd ngu ddn.
Hiub 1. c i u tnic 2.4.0 My
Qudc gia nay cd nhilu chugng trinh xdy dyng rgn nhdn tgo, thilt lap tren nhilu vung biln d cde Bang. Mye dich eua hg td thu hiit ea nham phat trien nghe cd giai tri, nghe ca thuang mat, bdo ton va phat trien da dang sinh hpe. Ben egnh dd. cac chuang trinh ndy eung nhim myc dich xu ty chit thai trdn d l t lien. Chinh vi t h i , vgt lieu sir dyng de tdm rgn nhdn tgo la cac dgng rac thai tdn nhu be tong, dd, ggch xay dyng, lop xe. cde logi d td. ca bm tdu lua, cdc togi tdu biln. Cdc khu rgn nhan tao dau tien dugc xdy dyng g Nam Carolina vao nhung ndm 1980 bang vigc su dung cae ngdi nha cu ndt trdn bd. Vdo thdi dilm do. ed ti-en 80% cdc bai ran nhan tgo d My sir dyng eac vdt li$u cu. Hlu het cde bdi ran nay dugc xdy dyng bdi cac nha tir tiiidn quan
ran nbin tao vAnh
tdm din sy phdt tiiln eua nghe cd nude nhd. Chfnh vi t h i , cdc bai ran dugc xdy dyng vd bdo v# rat thanh cdng tren ca sd quan ty dya vao egng ding.
Cy t h i . cdc diem du tjch cdu cd gidi tri vd tdn bien da tiiu hiit han 65% tugng khdch so vdi cdc ndm trudc khi xay dyng rgn, lgi nhudn eua nghi cd ven bd tang tir 5% ten 40% vd nghi cd thuong mgi tang tir 10% tdn 15%.
Den nhirng nam 1970, cac nhd khoa hgc d My bat dau thiet k l vd thir nghidm eac loai rgn vdi cdc toai vdt ti^u khac nhau nham tgo nai sinh cu tot nhit cho cde toai sinh vdt biln. Kit qua cho tiily, cac bai rgn dugc che tao bdng be tdng cho higu qud cao nhit. Cg the, dp I n djnh vd tudi thg cao. khong anh huang xau den mdi titrdng, tgo moi tiud'ng cho thye vdt. sinh vdt bdm trii va phdt triln [1].
Hinb 2. Sii- dung vSt li^u cii tao ran nbin t^o it Florida
an may bay 2 lac tg boc Ihep)
Tgp chi Khoa hgc - Cong nghe Thiiy sdn So 3/2013
2.5. OAn Dd
Vdo nhung ndm 60 eua t h i ky XX. vai sy phdt trien khdng ed kilm soat eua nghe tudi keo day da Idm cho nang suit danh bat d eac ngu tiirdng sgt giam nghiem trgng, tdc ddng tieu cyc din cde eong dong ngu ddn song phg thupc vao nghi ddnh bit tiiOy sdn. D l trd lai mdi trudng song cho cae lodi hai san. Chinh phii, eac to chire ehinh phii va phi chfnh phu da ten k l hogeh. dau tiJ phdt tiiln he tiling rgn nhdn tgo dge theo bd biln d Trivandmm. Sau 4 nam hoat dgng. cdc nhd khoa hgc da kit luan ring: Tai nhirng khu vyc tha ran nhan tgo ed mire da dgng sinh hoe eao han 90.8% so vdi edc viing ldn cdn khdng cd rgn; nang suit ddnh bat cao hon 70% dli vdi cac lodi cd, 60% cho ddng vdt thdn mIm. 87% cho cae loai d|ng vdt khdng xuong song [9. 11]. ti bd biln Karaikal. Chinh phu da cd chuang tiinh xdy dyng rgn nhan tgo nhdm phdt trien nguon igi thuy sdn vd tgo sinh k l cho egng dong ngu ddn ven biln. Thdng qua dy dn ndy. mdi tixrdng song cua edc toai sinh vat biln dugc phgc hoi, tgo mit xich diu tien trong chuoi thuc dn ciia cd. Chfnh vi t h i , mgt dp ed tap tmng day ban, phgc vy ddnh bit tot ban, giam chi phi nhien lieu nhieu ban. Dy dn eung da ho trg eho 500 hg ngu dan sing d 4 Idng ed tiong khu vye vay v i n va chuyen dli nghe nghidp. Sau 2 nam tiiyc hi^n dy dn, san lugng cd ddnh bat tdng ldn 30 lan [10].
2.6. d Malaysia
Khu ran nhan tgo d i u tidn duac xdy dyng a Sabah vao ndm 1975 nhim tdng nang suit sinh hpe. tdp trung nguon lgi thuy sdn d l phuc vg nghi cd gidi tri vd ngdn chgn nghe khai thae hai sdn bing
ludi keo. Ting didn tfch ran san hd nhdn tgo md quoc gia xdy dyng eho den nay udc tfnh khodng 30 km^ dugc ehia thdnh 8 viing rgn, dg sau l i p dgt ti>
5-30 meL Vgt lieu sO dgng de lam rgn nhan tgo bao gom tau thuyen eu. lop xe. mdy mdc hdng, da tang, kim toai va sau nay Id be tdng cdt thdp.
Vdi chuang trinh xdy dyng rgn nhdn tgo nay da giiip cho khodng 300 hd ngu ddn xung quanh khai thdc cd hieu qua cao. Ben cgnh, dd nganh du lidi va dich vg eijng dgt duge nhilu k i t qud. Chfnh vi the, hp dang tilp tuc thye hign nhilu dy dn tuang ty d l phgc vg phdt trien kinh t l thiiy san vd du lich, gidm mire chenh lech giau ngheo giua thanh thi vd viing sau, viing xa [12].
2.7. OPhilippin
Philippine id mdt quIc gia diu tu khd mgnh vdo vigc xay dyng ran nhan tgo, khdi dau Id dy an d Dumaguete vao nam 1977. Den nay. quoc ddo ndy da xay dung va lip dgt duge gan 100.000 dan vj rgn, chia thanh 11 viing va dat dign tieh khoang 40.000 km^ Sau khi du an ket thiic, ngudi ta da danh gid vd ed kit ludn rat kha quan ve vigc sir dyng ran nhan tao trowg phdt tnen nghe ca, du tjch va kinh t l xa hgi aia viing ven bien. Cu the la tgi ieh tu nghe ea thuang mgi tang len 30%. tu nghe ea gial tri tang len 31.5%.
Qua 9 lan theo dol (khoang 25% dign tfch) vung ran nhan tao. ket qua dgt duoe la san lugng danh bit d rgn nhdn tgo eao hon 150 lan so vdi sdn lugng d cac viing ran ty nhien. Ben egnh dd. sire san xuat sinh hge eung duge phye hdi ddng k l , chat lugng mdi trudng song eho ede loai sinh vat bien duoc cai thien vd do Id gid trj rat to tdn nhat ma du an mang lgi.
Hinh 3. c i u true r^n 2.8. 0 Dal Loan
Tir nam 1951 vdi chuang trinh cdt gidm so lugng tdu thuyin ddnh ea d l giam cudng lyc khai thde, bao ve, khdi phye nguIn loi hai san va phdt triln da dgng sinh hge eua ehfnh phii So tuong tdu thuyin du thua da dugc chinh phO mua lgi gan 1.000 chiee, s l tau ndy khi c i t gidm dugc ddnh ddm tgo thdnh eac bdi ran nhdn tgo eung d p mdi trudng sing ciia cde lodi hai sdn [2].
Ndm 1974. Odi Loan tiln hdnh xay dyng cae khu rdn nhdn tgo tgi mien Bde. Sau 1 nam thiet lap.
k i t qud thu duge la r i t kha quan, cd 24 loai thiiy san den sinh san so vdi tarde khi tha ran.
nhan tao ff Philjppin
Nam 1990, ede nhd khoa hoc b i t diu nghien euu va xay dyng khu ran nhdn tao d miln Nam Ddi Loan. Sau 1 nam khi thdnh tdp. ngudi ta da ghi nhdn td san tugng danh bit tang 1.6- 2,7 tin so vdi tiirdc khi xay dyng, nang suit danh bit ciia 1 tim ludi re trong ban kinh 50m so vdi vting ran dgt 1.24 - 3.56 kg vd ngoai ban kinh do chi dgt 0.45 - 0.95kg. 6 Hslnkang Pier, sau 6 thang lip dat, hg da khai Uiac dugc 20 tin hai san eac logi, san lugng trung binh tnrdc khi ldm rgn chi dgt 180 kg/tdu/ngdy, nhung sau dd da tang ten 400 kg/tdu/ngdy. Ben cgnh sdn luang khai thdc tdng ten. ehi phi nhien lieu cdn duge giam xuIng khodng 15% so vdi tarde khi xdy dung rgn.
TRUONG OAI HOC NHA TRANG • 193
Tgp chi Khoa hoc - Cong nghe Thuy sdn So 3/2013
3. Vat lieu vd cau trdc rgn n h i n tgo Cae nhd khoa hgc da ting kit cd 02 nhdm vdt tigu c^inh dugc sir dung d l xdy dyng rgn nhan tgo, tiiy thudc vdo mye dieh tgo ran vd vimg bien l i p dgt.
D l i vdi nhdm vat tigu ti/ nhien, bao gom: Tre eay, cdnh cdy, td dira, dd rgn, da tang, ddy thirng. g l , . . Dugc tip dgt d dgi duang va vung cira sing phye vg cho nghi cd thu cdng, nghe ed thugng mgi va mgt so it Id nghi cd gidi tri. Dot vdi nhdm vdt li^u nhan tgo. bao g i m : Be tdng, cao su, nhya PVC.
thdp. bdn chira nhidn li§u. tdu thuyen cu va cde khdi be tdng c6t thdp duge che tgo chuyen biet tap d dgi dugng vd biln khgi phgc vu eho nghe ea thuang mgi, khdi phgc mdi tivdng song vd tap tmng edc ddn cd dgi duang phye vg khai thde.
Cung gilng nhu edc ITnh vye khac, md hinh vd c l u tiiic rgn nhdn tgo ti^n the gldl cung duge phdt tnln theo IQ tiinh phdt tiien eua khoa hpe edng ngh$. Vdo thai ky d i u , hau h i t ede logi ran trdn the gldl dugc chl tao dan gidn hoge ehi don thuin Id vdt till cu (do dung gia dinh, c l u kign bd tdng tir nhd, c l u dudng), dd tang hay mdt so kit elu bing tiB, g l . l i p xe. tdu thuyin cu... [7,8]. Tuy nhidn, cdc c l u ki^n rgn nhdn tgo ty nhidn vd tdi sir dyng it hip din ede lodi sinh vdt biln. Han nua, mgt so
vdt ligu cu sir dgng tdm rgn nhan tgo cd tac ddng khdng t i t d i n mdi trudng nude va ngudn tgi sinh vdt nhu top xe, xde may vd c l u kidn khdc s i t [10].
Nhu vgy, trong qud ti'inh xdy dyng rgn nhdn tgo phdt tiiln nghe cd t^ln chit y d i n togi vat tigu nhim ddm bdo dd b i n cao, khdng gdy tdc dgng mdi tnrdng vd ngudn Igi thiiy sdn.
Ciing vdi ijch sir ra ddi rgn nhan tgo, Nhdt Bdn td quoc gia khdi d i u cho vi$e nghien ciru. thilt ke vd thir nghigm eac c l u tnic rgn hidn dgi phgc vy phdt triln nghe ea Day td ca sd Idm nIn tdng cho cdc nude vd cde nha khoa hgc tren the gidi tilp tyc triln khai cdc nghien euu, irng dgng vdo tung khu vyc vdi myc tidu vd c l u triJc ran khde nhau. Qua qud trinh nghidn ciru, cdc nhd khoa hge da k i t lugn rang sir dgng rgn nhan tgg bang bd tdng dgt kit qud eao nhit. dd la: (1) Khdng tac dgng tieu eye len mdi trudng song; (2) Dg ben tdn, de c h l tgo vd tap dat; (3) Kien tgo dugc nhilu dgng hinh t h i , kfch thude vd khoi lugng theo mong muon vd (4) cd khd ndng thu hdt cdc cdc lodi thuy sinh cao. Tuy nhidn, xdy dyng ran nhan tgo bing be tdng cung khd ton kem vd tiiy thugc vdo dieu kign eiia tirng qudc gia. vung mien md tya chgn phugng dn eho phii hgp [6].
HJnh 5. Ciu triJc v^ kfch thinyc mpt sd r^o nhSn t^o tren the gi6i
(I, 2 Phap, 3. 4 Nhai BmtvaS Hong Kong)
Tgp chi Khoa hoc - Cong nghe Thuy sdn So 3/2013
Cho d i n nay. tren the gidi cd r i t nhieu loai eautnic rgn nhdn tgo khac nhau va chua ed cdng trinh ndo khing djnh cau tnic ndo t l i uu nhit cho viee bdo v# vd phat trien nguIn lgi thuy sdn. Cdc nhd khoa hgc eung da chung minh rang d l i vdi cdc togi rgn ed kit eau phue tap vd do so cd kha nang thu hut dugc nhieu lodi smh vgt biln d i n sinh song.
Nguge tgi, edc togi rgn cd kit d u don dieu. dg che phii nhd se ft h i p dan cdc lodi thuy sinh. Ben egnh do. vige lap dgt rgn nhdn tao cOng dnh hudng den mgt dg vd so lodi thuy sinh din tni ngy Nlu lap dgt rgn nhdn tgo thdnh tirng cym. se thu hiit nhilu iodi thuy sinh vol mat dd cao hon so vdi tap dgt rieng le.
Vi vgy, khi xdy dyng ran nhan tao de tang cudng, bao v^ vd phdt triln ngudn tgi nen xdy dyng quy md du Idn, tip dgt thanh tung egm d l tang dO che phO tdn.
4. Khd ndng irng gng d- Vigt Nam
Vdi chilu ddi bd bien khoang 3.260 km, trdn 2.000 lodi hdi san. muc da dang sinh hgc cao. cd nhilu cua cira sdng, arng nggp mgn vd bai de eiia
nhilu lodi hdi sdn - dieu kign tot cho nganh khai thdc thuy sdn phdt trien. Tuy nhidn, dpi tdu khai thdc hai sdn cua nude ta phdt trien ngodi tam kiem sodt dgt gan 130.000 phuang tien, ca d u nganh nghe khdng hgp ty (18,5% tau ludi kdo, 41,4% tdu tudi rd, 5.7% tdu tudi vay, 17,1% tdu eau vd s l edn tai la eac nghe khde) vd ty trgng ddi tdu khai tiidc ven bg chilm gin 92% nen da gdy dp lyc ldn len ngudn lgi han san vd dgc bidt a khu vyc ven bd [4].
Ben canh dd, cdng tac quan ly cdn nhieu bat cap nen tinh trgng vi phgm cdc quy dmh v l quan l^ khai thdc cua ngu ddn r i t phd biln (100% tdu ludi kdo vl phgm quy djnh kieh thude mat dugc phep sir dgng d dgt ludi) [3] Chinh vi vdy, nguon lgi thuy san da vd dang suy giam rit nghiem trong, dnh hudng rat ldn den smh k l ciia ngu dan ven bien va chien tugc phat trien nganh thiiy san ciia nude ta
D l bdo vg vd phyc hoi nguIn lgi thiiy san phgc vy phdt triln nghe ed theo hudng ben virng. ngodi cdc bien phdp da thye hien nhu hien nay can trien khai nghien euu vd xdy dyng ede bai rgn nhdn tao tgi vimg bien ven bd Id rat d n thilL
TAI LIEU THAM KHAO TUng Vift
1 Cue Khai ihac v^ bao v$ ngu6n loi thiiy san, 2001. Mgt so van de ve sii dung vii phdi tnen ben vung nguon lgi thiiy san.
2 Nguyen Quang Hiing, 2004. Vai tro cua ran nhan tao trong viec khoi phuc va bao ton nguon loi thuy san Proceeding ofthe 2nd Regional Workshop on Enhancing Coastal Resources. Training Department, SEAFDEC/TD, Thailand. Trang 4-8.
3. Nguyen Trpng Lirong, 2013, Bao cSo chuyen de Thuc trang bao quan san pham fren tdu luoi keo xa bo tai Vi?t Nam 4. VienKinh tS Quy hoach Thiiy san, 2012 Bao cao torn tit Quy hogch tong the phat trien nganh thiiy san Vi^t Nam den nam
2020, tSm nhin den nam 2030 Tieng Anh
5. Allan Lo and Adnan Tokac, 2002. Artificial reefs in Turkey ICES Joumal of Manne Science, 59: S192-SI95 6. Alevizon, W. S.. and Gorham, J. C , 1989. Effects ofartificialreefdeployment on nearby resident fishes 7 Artificial Reef Subcommittees, 2004 Guidelmes for marine artificial reef matenals.
8 Clark S, A.J Edwards, 1999. An evaluation of artificial reef stmctures as tools for manne habitat rehabilitation in the Maldives
9 Collms. K., Jensen. A., Robert, P & Rajan. J.B., 1995. Artisanal artificial reefs in Kerala, India 10. Collins. K. J. Collins, et al, 2002. Environmental impact assessment of a scrap tyre artificial reef 11. Devaraj. M , 1996. Artificial reef for artisanal fishenes enhancement an attempt otf tnvandrum coast.
12. Edward Wong Fal Hung, 1989. Artificial reef development and management inMalaysia.
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