342 Tuyen t§p Hpi nghi KHOA HOC TOAN QUCiC Vfe SINH HOC BitN VA P H A T T R | £ N BfeN VCTNG
HIEN TRANG NGHE KHAI THAC LlTOI KEO TINH SOC TRANG
Mai Viet Van
Khoa Thuy sdn, Dgi hpc Cdn Tha
I. M O DAU
Tinh Sdc Tring cd 72km bd biln (chiem 21,2% chieu dii bd bien cua Vift Nam). Dgc theo bd biln thugc tinh Sdc Trang cd 3 cira chinh chiy ra bien Ddng li cira Djnh An, cira Tran De (2 cira niy thupc sdng Hiu, khu vyc huyfn Long Phii) v i ciia My Thanh (thugc sdng My Thanh, khu vyc huyfn Long Phu v i VTnh Chiu) cd hf thdng sdag ngdi ching chjt vdi ngudn Igi thiiy sin phong phu v i da dang. San lucpng khai thic hing nim dat 24.980 tan hii sin (Sd Thuy san Sdc Tring, 2004).
Theo Vifn nghien cim hii sin (2005) thi ning suit khai thic binh quan d ngu trudng Sdc Tring giim lien tuc, ning suit dinh bit nim 1985 la 1,11 tin/CV/nam thi den nam 2003 gia trj niy cdn 0,35 tin/CV/nim vdi tdc do giim binh quan 0,04 tin/CV/nim. Theo Chi cyc bio vf ngudn Igi Thuy sin tinh Sdc Tring (2004) thi toin viing xic djnh dugc 661 loii thugc 319 gidng vi 138 hp, trong dd loai cd gii trj kinh te khoing 100 loii v i dien bien sin luang khai thic thuy sin ciia tinh Sdc Tring thdi ky nim 2001 - 2004 vdi sd lucTng tiu thuyen khai thic thuy sin tai tinh Sdc Tring nam 2001 (503 chile) den nim 2004 (1.087 chiec), tdng cdng suit nim 2004 la 60.187 CV, ngoii ra hing nim cd tren hing ngin lugt tiu thuyen tir cic tinh khic vio khai thac tai vimg bien Sdc Tring. Ben canh dd tdng sin lucjng khai thic thiiy sin nim 2001 li 31.755 tan den nam 2004 la 31.804 tin. Tir dd cho thiy sd lugng tiu thuyen khai thic ngiy cing tang vdi tdc dp nhanh cdn sin lucTng khai thic thiiy sin ting nhung khdng cao. Dieu niy chimg td nguon lgi thiiy sin trong khu vyc tinh Sdc Tring dang suy giim, mgt sd bai ngheu, sd huyet, bai de ciia cic loai ci khdng cdn dugc an toin, din den sd lucmg ciia mgt sd loii c i cd gii trj kinh te giam ding ke, thim chi khdng cdn du de duy tri nghe khai thic nhu hg c i Nhim, c i Dudng, c i Ggc,...
Hifn nay sd lupng phuang tifn niy quay trd lai hgat dgng d ven bd, lim can kift ngudn Igi thuy sin ndi rieng vi mdi trudng ndi chung (Sd Thuy sin Sdc Tring, 2004). Sy suy giim nghiem trpng ciia ngudn Igi thuy sin ven bien da tic ddng manh mang tinh tieu cyc den ning suit va hifu qui khai thic ciing nhu hifu qui cua cic md hinh nudi thuy sin ven bien cd lien quan tdi ngudn lgi va hiu qui cudi cimg li giy ra nhting tic dgng 1cm ve kinh te - xa hgi doi vdi cic cgng ddng ven bien (Le Xuin Sinh, 2006).
Xuit phit tir thyc trang tren, de tii nghien ciru "Hifn trang nghe khai thic ludi keo tinh Soc Tring" di dugc thyc hifn, ket qui nghien cim se lim ca sd khoa hgc cho vifc quin ly vi phat tnen nghe niy d tinh Sdc Tring ndi rieng v i cho viing Ddng bing sdng Ciru Long ndi chung.
II. VAT LIEU VA PHUONG PHAP NGHIEN ClTU L Dja diem va thdi gian nghien cuu
Di tii khio sit tai tinh Sdc Trang tir thing 01/2008 den thing 12/2008.
I
Tieu ban: TAI NGUYEN SINH V A T BI^N VA N G U O N Lcyi 3 4 3
2. Thong tin thu cap
Ndi dung thdng tin can thu thip gom: Ngu trudng; Nguon lgi; Dieu kifn ty nhien; Die diem thinh phin loai hii sin ciia nghe ludi keo.
3. Thong tin so cap
Thdng tin sa cip dugc thu thip qua phdng vin true tiep ngu din hinh nghi ludi keo bing bing ciu hdi soan sin. Cic bien sir dung trong bing ciu hdi gdm cd: Thdng tin tiu; Ngu trudng;
Ddi tucmg khai thic; Sin luang khai thic.
Tdng sd miu khio sit li 66 mau (33 mau tiu cd cdng suit > 90 CV v i 33 mau tau cd cdng suit < 90 CV).
Xu ly thong ke
Sir dyng phin mem thdng ke SPSS verson 13.0 v i phin mem Excel de tinh toan cic gii trj trung binh v i do Ifch chuan cua cic sd lifu khio sit.
III. KET QUA - THAO LUAN
1 Khao sat hifn trang nghe khai thac hai san d tinh Sdc Trang
Ket qui thdng ke ve tinh hinh che bien v i xuat khiu thiiy hii sin tinh Sdc Tring tir nim 2003 den 2007 dugc trinh biy tren bing 1.
Bang 1. Tinh hinh c h i biln va xuit khau n i m 2003 d i n 2007
Nam 2003 2004 2005 2006 2007 So nha may che bien (Cai)
Nguyen lieu thu mua (Tan) Thanh pham che bien (Tan) San luong xuat khau (Tan) Kim ngach xuat khau (Tri^u USD)
(Nguon: Sd Thuy sdn tinh soc Trdng, 2004-2008.)
Qua bing 1 cho thiy, nginh thuy sin Sdc Tring tir nim 2003 - 2007 cd xu hudng phit tnen. Trong dd, nam 2007 dat kim ngach xuit khiu 356,011 trifu USD (tang 9,18% so vdi cimg k\' nim 2006) vdi sin lucpng xuat khiu thiiy hii sin dat 42.000 tin. Tinh den nim 2007 Sdc Tring cd 9 nhi miy che bien vdi sire mua nguyen lifu dat 80.000 tin v i lugng thanh phim che bien dat 60.000 tin trong dd tdm ddng lanh 47.200 tin. Die bift l i mat hing che bien c i tra, chi ci ddng lanh da mang lai gii tri xuit khiu khoang 18 trifu USD, ting gin gip ddi so vdi cimg ky nim 2006 Nim 2007, thi trudng xuit khiu thiiy hii sin chii yeu ciia tinh Sdc Tring li Nhit (42,5%), My (31%), EU (i2,4%), Thj trudng khic (14,1%).
Ket q u i thdng ke ve tinh hinh sin lucpng v i tiu thuyen khai thic hii sin ciia tinh Sdc Tring tir nim 2003 den 2008 dugc trinh bay tren bing 2 va bing 3.
8 22.773,6 29.174,2 26.399,3 273,536
9 45.610,5 36.944,3 29.644,5 297,981
9 46.389,3 35.247,8 34.426,0 284,480
9 48.456,5 37.798,7 32.342,6 326,081
9 80.000 60.000 42.000 356,011
344 Tuyen tgp Hpi nghj K H O A HOC TOAN Q U 6 C Vfe SINH HQC B I ^ N VA PHAT TRlfeN BfeN VU'NG
Bang 2. San lug-ng khai thac thuy hai san nam 2003 d i n 2008
Nam Tom (tan) Ca (tan) Mgc (tan)
Thuy san khac (tan)
San luong khai thac bien (tan) Tong san lucyng khai thac toan tinh (tan)
2003 2.670 21.286
1.294 25.250 33.200
2004 1.952 18.713
4.513 25.178 31.395
2005 2.132 21.805
498 24.435 29.235
2006 2.665,0 18.944,3
5.393,2 24.743 31.870
2007 3.688,633 14.814,478
3.168,5 28.330 34.370
2008 3.700 17.500
8.400 29.600 34.600
Nguon: Niim gidm thong ki Soc Trdng, 2008; www.nongnghiepsoclrang.gov, vn (Cap nhdt ngdy 07/07/2009)
Bang 3. Sd luang tau
Nam Tong tau thuyen (Chiec) Tong cong s u i t (CV)
thuyen khai thac thijy hai san tCr nam 2003 den 2008
2003 640 49.137
2004 677 53.211
2005 1.104 59.901
2006 1.181 67.879
2007 1.157 79.360
2008 1.162 92.320
Nguon: Tong cue Thong ke. 2006; Sd Thiry sdn tinh Soc Trdng, 2004-2008.
Tir bing 2 v i bing 3 cho thay, tdng sin lugng thiiy hii sin khai thac bien tai Sdc Trang cc xu hudng ting tir nim 2003 den nim 2008. Phuong tifn tham gia khai thic ciing ting nhanh Her tuc c i ve sd lugng lan tdng cdng suit miy tiu. Die bift thdi gian gin day, tai ngu trudng viing bien ven bd Sdc Tring- Bac Lieu sd lupng tiu thuyen trong va ngoii tinh den khai thic thuy san tang dot bien. Theo sd lifu cua nginh chuc nang, tinh Bac Lieu cd khoing 400 tiu khai thac dinh bit thuy sin gin bd, chiem gin 50%) tdng sd tiu khai thic biln ciia tinh. Vimg biln nay con cd hon 100 tiu cdng suit nhd tir cic tinh lin can Kien Giang, Ben Tre, C i Mau... den khai thac, dinh bit trii phep. Cic phuong tien nay ty sing che ra cic ngu cu khai thic mang tinh tan dift nhu ludi the, ludi re, cio ddi, cio don... vdi kich cd mat ludi nhd, bit c i tdm c i ldn lin ci be.
Mdi ngiy cd hon 1 tin tdm, c i con v i nhieu loai thiiy sin cd gii trj khic da dugc khai thic bang cic hinh thire mang tinh hiiy dift, lim can kiet ngudn Igi thuy sin ty nhien viing biln niy (So Ndng nghiep & Phit trien ndng thdn Bac Lieu, 2008).
Ket qui thdng ke ve ca cau nghe khai thic bien tinh Sdc Tring nim 2008 dugc trinh bay trong bing 4.
Bang 4. Co* c i u n g h i khai thac thuy san b i l n tinh Sdc Trang nam 2008
Phan lo^i Co dinh
Nghe cau Nghe cao Ludi re Ludi vay Ngu eg khac Tong cgng
Sd tau (chiec) 85
15 340 260 57 27 784
Cong s u i t (CV) 2.835
2.268 54.075 6.155 18.145 6.850 90.328
Lao dgng (ngudi) 345
94 1.407 952 838
• 6 0 • • • ^ • '
3.696
784
Nguon: Chi cue bdo vi nguon lai thuy sdn Soc Trdng. 2008, 2009.
Nam 2008, tinh Sdc Trang cd tdng sd lugng tau thuyen tham gia khai thic thuy sin biln la chiec vdi tdng cdng suat 90.328 CV va tong sd lao dpng li 3.696 ngudi (bing 4). Sin lugng
Tilu ban: TAI NGUYEN SINH VAT Bl^N VA N G U O N LO!
545 khai thic hai san nam 2008 li 29.600 tan, trong do san lupng tdm la 3.700 tan, sin lugns c i li 17.500 tan v i cic sin lugng thuy sin khac la 8.400 tin (Bing 2). Ca cau nghi khai thic th\v hii sin d tinh Sdc Tring gdm nghe cd djnh, nghi ciu, nghi cio (ludi keo), nghi ludi re, nghi'ludi viy va cic loai nghe khic. Trong dd, nghi cao co tdng s6 tiu thuyin nhilu nhat li 340 chiec (43,37%) vdi tdng cdng suit 54.075 C V va tdng sd lao dgng 1.407 ngudi.
Nhdm tau cd cdng suit > 90 CV chilm so lugng nhilu nhit li loai tau 180 CV v i 280 CV trong khi dd nhdm tiu cd cdng suat < 90 CV thi tip trung nhilu nhit li loai tiu 55 CV. Tiu khai thac ludi keo cd cdng suat > 90 CV khai thic chii yeu d dp siu 30m v i 33m, cdn tiu cd cdng suit < 90 CV thi khai thic chu ylu d dp siu 25,5m. Miia vy khai thic chu yeu li vu Nam (tir thing 3 den thing 9 trong nam, trong dd khai thic tap trung tir thing 5 den thing 7).
2 San lugng va thanh phan loai hai san khai thac trong nghe ludi keo d Sdc Trang 2.1. Kit qud phdn tich ve sdn luang khai thdc theo cong sudt tdu
Ket qui dilu tra vl sin lugng khai thic ciia tiu > 90 CV v i tiu < 90 CV theo cdng suat trong nim dugc trinh biy qua do thj (hinh 1 v i 2). Ket qui dilu Ua cho thiy, sin lugng khai thic ciia nhdm tiu > 90 CV ti If nghjch vdi cdng suit tiu, tire li sin lugng giim dan trong khi cdng suit tiu thi ting din. Tiu cd cdng suit 90 CV cd sin lugng khai thic cao nhat (290,45kg/CV/nim) v i tiu cdng suit 360 CV cd sin lugng khai thic thip nhit (47,94kg/CV/nam) (hinh 1). Ngoai ra sin lugng khai thic cua nhdm tiu < 90 CV cung cd sy giim din khi cdng suit tiu ting len, tuy nhien sy suy giam niy khdng cd tinh lien tuc nhu d nhdm tau > 90 CV. Tiu cd cdng suit 24 CV cd sin lugng khai thic cao nhit (472,65kg/CV/nim) v i t i u 56 CV cd sin lupng khai thic thip nhit (116,81kg/CV/nim) (hinh 2).
Ket qui nghien ciru cho thiy, tiu cd cdng suit ldn thi sin lugng khai thic lai giim v i sin lugng binh quan ciia tiu > 90 CV thip hon tiu <90 CV li 2,63 lin (80,20kg/CV/nim so vdi 210,89kg/CV/nam). Chim^ td tiu cd cdng suit > 90 CV khai thic khdng hifu qui so vdi tiu <
90 CV. Khi so sinh vdi ket qui nghien cim ciia Vifn Hii sin (2003) (sin lugng khai thic binh quin ciia Sdc Trang li 0,35 tin/CV/nim) ta thiy ngudn Igi thiiy sin ciia ngu trudng biln Sdc Tring da suy giim ding ke.
330.00 -P 300.00
« 270.00
^ 240.00 O 210.00
^ 180.00 150.00 120.00 90.00 60.00 30.00
I Duong bieu thj san luting binh quan theo cong suat tren nSm
OXi
g
t3
90 120 180 200 240 250 265 270 280 300 330 350 360 Cong suit (CV)
Hinh 1. San lug'ng binh quan theo cdng s u i t trong nam cua tau khai thac > 90 CV
346 Tuyen t?p HOi nghi KHOA HOC TOAN QU6C V6 SINH HOC BI^N VA PHAT TRI^N B^N VQ
Dudng bieu thj s i n lugng binh quan theo cong suat trong nam
1
Hinh 2. San luo'ng binh quan theo cdng suat trong nam ciia tau khai thac < 90 CV
2.2. Ket qud phdn tich ve sdn luang vd thdnh phdn lodi trong mot chuyen khai thdc
Ket q u i k h i o s i t ve t h i n h p h i n loii khai t h i c ciia t i u cd cdng s u i t > 90 CV d u g c bieu d qua c i c hinh 3 v i hinh 4.
sz Ghe do
• Mirc nang D Bach tuQC D Ghe xanh
• Ca moi n Tom gay
• Ca luai D C a d u
• Ca bong
• Tom giang D Ca chi vang Q Tom chi
• Tombac
• Cah6
• Tom sat
• Cathu H C a n g a t a C a b o D Ca duoi O Ca khoai O Tom the
Hinh 3. San lugng tirng loai cua tau > 90 CV
Tieu ban: TAI NGUYEN SINH VAT B l t N VA N G U O N L O I
D C i
Nhuyen the I Giip xic
DCi tap
Hinh 4. Ty 1^ cac nhdm loai ddi v d i io^i hinh khai thac t^u > 90 CV
Tir hinh 3 thiy ring, thinh phin loii kinh te khai thic dugc cua tiu cd cdng suit > 90 CV gdm 22 loii, tron^ dd loii dat sin lugng thip nhit li tdm the (195,8 kg chiem 0,37%o) vi loii dat sin lugng cao nhit li myc dng (15338,15 chiem 29,19%). Tir hinh 4 cho thiy, nhdm loii dat sin lugng cao nhit li nhuyen the (34,78%), giip xic (25,69%), ci kinh tl (16,39%)) vi ci phin (23,13). Sin lugng ca phin gin bing 1/4 tdng sin lugng khai thic xa bd.
Ket qui dieu tra ve thinh phin loii ciia tiu khai thic cd cdng suit < 90 CV cho thiy thinh phan loii kinh te khai thic dugc cua tiu cd cdng suit < 90 CV gom 18 loii, trong dd loii dat sin lugng thap nhit li ci ngit (205,8 kg chiem 0,67%) vi loii dat sin lugng cao nhit li tdm gay (6444,3kg chiem 21%) (hinh 5). Nhdm loii dat sin lupng cao nhit li giip xic (33,01%)), thin mem (20,07%), ci kinh tl (16,20%) vi ci tap (30,72%o). Sin lupng ci tap gin bing 1/3 tdng sin lugng khai thic gin bd (hinh 6).
• Tom gay
• Mirc ong n Muc nang D Ghe do
• Bach tuoc
• Ca moi
• Ghe xanh n Ca iuod
• Ca chi vang
• Ca hong D Ca dgng a C a h o
• Cadii
• Ca bo
• Ca thu
• Ca duoi
• Tom sat D Ca ngat
c
•<(U 3
c
Hinh 5. San lug'ng tirng lo^i ciia t i u < 90CV
348 Tuyen t^p HQi nghj KHOA HOC TOAN QUOC VE SINH HQC BI^N VA P H A T T R | £ N B £ N V
Hinh 6. Ty 1^ cac nhom loai ddi vd^i loai hinh khai thac tau < 90 CV
Thanh ph§n loai kinh t& khai thac d6i vai loai tau khai thac c6 cong suat > 90 CV (22 1 thi dugc nhilu hon so vai loai tau khai thac c6 cong suit < 90 CV (18 loai) nhung ngugc lai luomg ca phan khai thac doi vai loai tau c6 cong suat < 90 CV thi nhieu hem tau c6 cong su 90 CV.
Qua do CO thi thay rSng: thanh phan loai ca phan bo tai ngu truang tinh Soc Trang da c nhimg hieu qua khai thac lai khong cao, chii yeu chi tap trung khai thac cac loai ca con, kid nho, gia tri kinh te thap (ca phan). Do do, can c6 bien phap khac phyc de khai thac hi?u qua vira bao ve dugc nguon Igi thuy san vira bao ve dugc moi trirang sinh thai mot each ben vihif
IV. KET LUAN
Nghe luai keo ciia tinh Soc Trang c6 so lugng tau thuyen tham gia khai thac nhieu i trong tong co cau tau thuyen ciia tinh (340 chiec, chiem 43,37%) vai tong cong suat 54.075 va tong so lao dgng 1.407 nguai.
Nhom tau c6 cong suat > 90 CV chiem so lugng nhieu nhat la lo^i tau 180 CV va 280 trong khi do nhom tau c6 cong suat < 90 CV thi tap trung nhieu nhat la loai tau 55 CV. Tau 1 thac > 90 CV khai thac chii yeu a do sau 30m va 33m, con tau < 90 CV thi chu yeu a dp 25,5m. Mua vu khai thac chu yeu la vu Nam.
San lugng khai thac binh quan ciia nhom tau > 90 CV (80,20 Kg/CV/nam) thap honn nh tau < 90 CV (210,89 Kg/CV/nam) la 2,63 Ian. Thanh phin loai khai thac c6 gia trj kinh te vai nhom tau > 90 CV (22 loai) nhieu han so vai nhom tau < 90 CV (18 loai) nhung ngugc san lugng ca phan khai thac doi vai loai tau c6 cong suat < 90 CV thi nhieu hon tau c6 cong s
>90CV.
Ket qua nghien cuu cho thay boat dong cua nghe khai thac luai keo a tinh Soc Trang h nay tac dgng rat Ian den nguon Igi thiiy san. Vi vay, can phai tiep tyc nghien cuu tim ra nhi giai phap hiru hieu de bao ve va phat trien ben vung nguon Igi thiiy san nai day.
V. TAI LIEU THAM KHAO
1. Bg Thuy san, 1996. Nguon Igi thuy san Viet Nam. NxbNong nghi^p. 616 Trang.
Tieu ban: TAI NGUYEN SINH VAT B I E N VA N G U O N L Q I 349
2. Chi cue Bao ve nguon igi Thuy san Soc Trang, 2004. Bao cao t6ng kk cila Chi cue Bao ve nguon Igi Thuy san tinh Soc Trang.
3. Chi cue Bao ve nguon Igi Thuy san Soc Trang, 2005. Bao cao t6ng kSt ciia Chi cue Bao v?
nguon Igi Thuy san tinh Soc Trang.
4. Chi cue Bao ve nguon Igi thiiy san soc Trang, 2008. Bao cao t6ng k8t ciia Chi cue Bao ve nguon Igi Thuy san tinh Soc Trang.
5. Cue Thong ke Soc Trang. 2008. Niem giam thong ke Soc Trang 2007. Nxb Thong ke.
6. Le Xuan Sinh, 2006. Bai giang mon hge Kinh te thuy san. Khoa Thuy san, Dai hoc Can Tha.
7. Sa Thuy san tinh Soc Trang, 2004. Bao cao tong ket nganh Thiiy san nam 2003 va phuong huang nhiem vu nam 2004.
8. Sa Thuy san tinh Soc Trang, 2005. Bao cao tong kk nganh Thiiy san nam 2004 ya phuang huang nhi?m vu nam 2005.
9. Tong cue Thong ke, 2006. So lieu thong ke nong nghiep, lam nghi^p, thuy san.
10. Vien Nghien cuu Hai san, 2005. Tinh hinh nguon Igi va khai thac hai san biSn Viet Nam.
11. www.nonsnshiepsoctrans.sov.vn (Cap nhat ngay 07/07/2009)
S T A T U S O F T H E T R A W L N E T F I S H E R Y IN S O C T R A N G P R O V I N C E Mai Viet Van
SUMMARY
The estuarine and coastal zone of Vietnam are being expressed by inshore fishing activities (MOFI, 1996). Seriously decline of aquatic resources have negative impacts on productivity and effects with fishing and relevant aquaculture activities by using natural stocking, it also negative impacts on social economic of coastal communities (Le Xuan Sinh, 2006). The objectives of research is to determine of the status of the trawl net fishery in Soc Trang province. From the results of surveying 66 Fishing households and Managers on fisheries and fishing of Soctrang province show that the total of number of trawl net vessels in the Soctrang are 340 boats (43.37%) with 54,075 horsepower (HP) and 1,407 labours. Most of number of vessels > 90 HP are vessels 180 HP and 280 HP, and most of number vessels less than 90 HP are vessels 55 HP.
The trawl net vessels > 90 HP mostly operate in the fishing grounds at depth between 3 0-3 3 m, while the trawl net vessels less than 90 HP mostly fish at depth 25.5m. The main fishing season are from May to July yearly. The total average catches of vessels > 90 HP less than vessels < 90 HP is 2,63 times (80,20 Kg/HP/year in companson with 210,89 Kg/HP/year). The fishing species component of vessels > 90 HP more than those of vessels < 90 HP (22 species m comparison with 18 species). Conversely, the total catches of trash fish of vessels < 90 HP more than those of vessels > 90 HP.
The results show that fishing activities of the trawl net is being strongly effected on marine resource in Soc trang. So, this fleet needs to be appropriately developed in order to sustain the resources and the fishery itself
Keywords: Status, fishing, trawl net, Soc Trang
