398 Tuyln tip HQi nghj KHOA HQC TOAN QU6C v £ SINH HOC BI^N VA PHAT TRj^N B^N V O N G
ITNG DVNG KET QUA KIEM DINH DQC TO TREN SINH VAT BIEN NHir MQT CONG CU DANH GIA NGUY CO SINH THAI
CHO VUNG VEN BOf TINH BINH DINH
Hoang Trung Du
Vien Hai duang hpc, Vi?n Khoa hpc vd Cong ngh4 Vi^t Nam
I. MOf DAU
Viec 6 nhiem moi truang bai chat hoa hpc deu c6 nhimg anh huang dpc hai, va tac done ve muc dp dpc hai cua chiing thuong dugc danh gia dya fren nhCmg hipu img ve mat sinh hpc cua sinh vat. Ky thuat kiem djnh dpc tinh la phuang phap xac djnh hay danh gia sy hien dipn hoac nhirng tac dpng cua mpt chat hay nhieu chat duai dieu kipn nhat djnh ve mat sinh hpc thong qua viec sir dyng sinh vat hoac timg thai ky phat trien cua bp phan sinh vat lam thi nghipm. Cac thi nghipm sinh hpc dugc do bang mure dp phan ling - hipu ling sinh hpc qua thai lugng tilp xiic cua sinh vat voi chat c6 kha nang mang thanh phan gay dpc (Chapman va cs, 2002, Walker va cs 2006). Vipc kiSm djnh sinh hpc c6 the fren hanh a quy mo ca the, quan the hoac a mire do cao ban (la cac mo hoac te bao), eac doi tugng sinh hgc thuong dugc su dyng de xem xet miic dp anh huang, ciing nhu nhimg thay doi gay ra bai nhimg tac dgng cua 6 nhilm moi fruang. Thong qua cac hipu ling sinh hpc ciia sinh vat de dua ra chi so de danh gia ve miic dp anh huang va tac dpng bit lgi doi vai chiic nang cua bp sinh thai (ASTM, 1994).
Khoang ban 10 nam fra l^i day, ky thuat kiem djnh dpc to da dugc tri€n khai tai Vipn Hai duong hpc, vai nhirng nghien curu danh gia anh huang ciia cac hgp chat dimg frong khai thac dau khi nhu bim khoan, chat phan tan (Nguyen Tac An, va cs, 1998). Trong chuang trinh hgp tac ASEAN-Canada, phong thi nghipm da nhan dugc sy giiip da rat nhiSu tir chuyen gia Canada v8 vipe xay dyng va sii dyng ky thuat kiem djnh trong nghien ciiu tac dpng cua cac kim loai nang CO hipu img sinh hpc (bioavailable) len cac loai sinh vat bien khac nhau (Le Lan Hucmg va cs 2002). Da CO nhimg nghien ciiru ve anh huang cua kim loai nang (Zn, As) doi vai cac loai sinh vat nhu tao dan bao, au trimg cau gai, tom sii, vem xanh, ca chem,... (Le Lan Huong, 2000 V6 Hai Thi va Le Hoai Huang, 1998). Tu nam 2004 den nay cung da thyc hien mgt so nghien ciiu ve danh gia nhung anh huang dau thai doi vai 2 loai tao dan bao va vpm xanh (Hoang Trung Du va cs, 2004, 2005); danh gia anh huang 6 nhiem cua fram tich cang bien frong vjnh Nha Trang doi vai qua trinh phat triln cua au trimg cau gai (V6 Hai Thi va cs, 2006). Cac ket qua fren la nhimg buac tiep can quan frpng doi vai viec nghien ciru dpc to sinh thai hpc, la cac ca sa cho vipc phat trien, tang cuong giam sat de danh gia va canh bao nhimg nguy ca c6 th8 xay ra doi vai 6 nhiem moi truang. Cac ket qua nghien cim da danh gia dugc mire dp anh huang khac nhau do 6 nhiem moi truang tai sinh vat thiiy sinh (dac bipt la nhimg sinh vat c6 dp nhay cam vai cac sfress vh moi truang) ngay trong thai diem hipn tai va giiip cho vipc canh bao nhimg anh huang tuang lai, mang tinh lau dai doi vai vyc nuac ven ba. Cho den nay, tao dan bao, c4u gai den , tom sii va ca chem da dugc lya chpn su dyng lam sinh vat kiem djnh, mpt mat vi nhung loai nay phan bo frong virng bien ven bo va dugc sir dyng rong rai frong rat nhieu nghien ciiu kiem djnh a khu vyc ASEAN (Le Lan Huang, 2000; 2002).
Trong moi truang bien, cac sinh vat d8u tao ra cac phan img sinh hpc khi c6 nhime tac 3ng vao qua frinh s6ng eua chiing, va phan ling se thay doi phy thupc vao timg giai doan va liic dp nhay cam cua sinh vat. Vi du: d6i vai cau gai a cac giai doan vong dai (au trime con
Tilu ban: CONG NGHE SINH HQC BI^N VA M 6 | TRt/6'NG 399
non, va truang thanh) se c6 mii-c dp nhay cam doi vai nhimg 6 nhiem moi truang khac nhau.
fvlpt so nghien ciru da chi ra rang hau het sinh vat cau gai a giai doan phat trien au trimg, chung s6ng nhu 1 sinh vat phii du, froi noi trong cot nuac, va au trimg se tiep xuc tryc tiep vai moi truang nuac la chii yeu. Bai vay, au triing cau gai se chju tac dpng ciia nhieu thanh phan chat hoa tan frong nuac nhu kim loai nang, thuoc trir sau,... Theo mpt so nghien ciru cho rang a giai doan phat trien au trimg, cau gai noi chung rat nhay doi vai cac chat 6 nhiem hiru ca nhu thuoc ffir sau, Tributyltin (TBT) va kim loai Cu va As hoa tan frong nuac (Rosen va cs., 2008). Trong thyc te de phan tich toan bp cac chat ton tai trong moi truang doi hoi kinh phi, thai gian va cac thiSt bj chuyen dimg dat tien. Vai viec sir dung tap hgp danh gia tir cac chi so va ket qua thi nghiem kiem djnh fren sinh vat, se tao thuan lgi giiip cho ta c6 nhin nhan khach quan ban, va hieu ro ban ve dieu kien ty nhien hoac nhimg ton tai von c6 ciia moi truang song. Vi vay, danh gia mire dp dpc hai ciia moi truang la thong qua cac phan ling ciia sinh vat doi vai moi truang song cua chiing (chii frpng vao hgp phan sinh hpc va moi tucmg quan) (Long va cs., 2003;
Macfarlane va Burchett, 2001), dong thai tiep can hipu qua se la danh gia chat lugng moi truang va dya vao moi quan he cua no trong tucmg tac vai he sinh thai. Myc tieu cua kiem djnh dpc tinh fren sinh vat la cung cap thong tin khoa hpc chinh xac, dii tin cay ve nhting kha nang anh huang to hgp cac chat boa hgc hien dien frong moi truang, tir do danh gia tac dpng dpc hai len cac sinh v^t thiiy sinh.
Binh Djnh la tinh duyen hai Nam Trung bp nam frong virng kinh te frpng diem mien Trung, viing ven bien ciia tinh gom 4 buypn Hoai Nhan, Phii My, Phii Cat, Tuy Phuac va thanh pho Quy Nhon vai 30 xa, phuang. Virng ven bien Binh Djnh co vj fri rat quan frpng ve quoc phong, an ninh, dan cu chiem gan 68%) dan so ciia tinh: co trung tam kinh te, van hoa, chinh trj nhu thanh pho Quy Nhan va cac thj fran, huyen ly. Theo bao cao dieu tra ciia Ha Thanh Huang tit nam 2005 - 2007, chat lugng moi trucmg nuac bien virng ven bor ciia tinh da co nhimg thay doi, mpt so ket qua quan trac moi truang nhan thay rang mau nuac bien da co chi tieu vugt qua tieu chuin cho phep (QCVN 10: 2008/BTNMT). Tinh frang 6 nhiem hihi ca da phat hipn dugc tai vjnh Quy Nhon, va mpt so diem khao sat frong dam pha ven bien nhu Thj Nai, De Gi, ngoai ra cung da co sy nhiem ban eye bp kim loai nang nhu Cu (Ha Thanh Huon^, 2007). Bai vay, thyc hien cac khao sat tai dam Thi Nai va sir dyng cac ket qua thi nghipm kiem djnh ve dpc to moi truang doi vai sinh vat bien, la ca so va thong tin cho nhimg danh gia miic dp nguy ea sinh thai xay ra cho virng bien ven ba.
n , P H U O N G P H A P NGHIEN ClTU 1. Khao sat, thu mau moi trircmg
Vai 2 dgt khao sat: thang 8/2007 va thang 5/2008. Cac vi tri thu mau dugc trinh bay frong hinh 1
Mau nuac dugc thu bang binh lay mau Niskin 51it cua My, mau dugc lay a tang mat (duai mat nuac 0,5m). Mau nuac dugc do dac cac thong so pH, nhipt dp, dp man ngay tai hien trucmg va mau sir dyng frong kiem djnh dpc to dugc giir lanh bang cac thiing da, sau do dugc chuyen cha bang xe 6 to va thyc hien thi nghipm ngay hom sau tai Vipn Hai duong hpc.
Nhiet dp, pH, dp man dugc xac djnh tryc tiep ngay ngoai hipn fruang (in situ) bang may do
<ia nang HORIBA (Nhat Ban). Ham lugng Oxy hoa tan (DO) dugc phan tich bang phuang phap chuan do Winkler. Mau nuac dugc thu va bao quan lanh, sau do dugc phan tich vai cac thong so nhu kim loai nang, thuoc trir sau, diing de xem xet sy hien dipn cua cac ygu to nhiem ban nguy hai trong mau
400 Tuyen tgp Hpi nghi KHOA HOC TOAN QU6C VE SINH HQC BI^N VA PHAT T R I E N B E N VCrNG
Mdu trdm tich dugc phan tich thuoc trir sau va kim loai fren may sac ky khi HP-6890 vcri cac dau do FID va ECD (U.S EPA SW-846) va may hap phy nguyen tir (AAS - Shimazu) (thee APHA, 2005)
Hinh 1. Ban dd vj tri cac diem thu mdu trong ddm Thi N9I (12 diem)
2. Phvong phap tien hanh cac thi nghiem kiem djnh tren sinh vat bien
Kiem djnh dpc to cap tinh dugc thyc hien theo huang dan dugc mo ta frong ASTM (1994) va theo sach Huong dan cac buac tien hanh frong thi nghiem kiem djnh dpc to cap tinh tren ca va than mem (CPMS-II, 1998).
Chuan bj dung cy thi nghipm va cac thiet bi: dyng cy cho thi nghipm nhu pipet ty dpng va thuy tinh, coc dong, binh tam giac (250ml), ong nghiem thiiy tinh, be thuy tinh (lOL),... Cac may do pH, nhiet dp, dp man, oxy boa tan, may sue khi, bam hiit chan khong, pheu Ipc va giay Ipc, kinh hien vi va buong dem,... Phong thi nghiem dugc chay dieu hoa va on djnh nhipt dp phong khoang 25 ±1°C
Dung dich lam kiem dinh: Mau nuac dugc giir lanh trong suot thai gian chuyen cha tir hi?n truang ve phong thi nghipm, sau do dugc tien hanh thi nghipm ngay. Mau nuac dugc sir dung vao frong thi nghipm kiem djnh la mau nuac giir nguyen goc (100%) dugc thu tir ngoai thyc te.
Doi vai kiem djnh cho mau tram tich, chimg toi sir dung nuac chiet tram tich (NCTT) de lam thi nghiem kiem djnh (18g/900ml trong nuac bien), sau do xao frpn deu va de lang trong 4h, lay phan dich a fren lam dung djch kiem djnh theo huang dan dugc mo ta frong ASTM (1994)
Sinh vat bien dimg frong kiem di.ih la tao Chaetoceros muelleri, au triing cau gai den Diadema setosum, va vem xanh Perna viridis
Tieu ban: CONG NGHE SINH HOC B I E N VA MOI TRl/ONG 40 1
Tao C. muelleri dugc nuoi cay va giir giong tai phong thi nghiem. Mat dp tao diing de thi nghiem ban dau dieu chinh co mat dp vao khoang 1 x 10* te bao/ml. Sir dung muoi dinh duang de sy duy tri sinh fruang, phat trien ciia tao
Cau gai den Diadema setosum: Cau gai bo me (con dye va con cai fruang thanh) dugc bat tai khu vyc bao ton bien - dao Hon Mun (MPA), sinh vat chpn thi nghiem co kha nang phong tinh triing va de trimg trong dieu kien phong thi nghiem khi c6 sy kich thich. Thi nghiem kiem djnh sir dung a giai doan hinh thanh au triing sau khi da dugc thy tinh thanh cong.
Vem xanh Perna viridis, con non (kich thuac L= 27.3 ± 1.3mm). Vpm dugc dua ve phong thi nghiem, lam sach va nuoi nhot cho thich nghi vai dieu kipn phong thi nghiem (tir 2-3 ngay).
Sau do lya chpn con khoe va co kich thuac tuong doi giong nhau dua vao sir dung trong thi nghiem.
3. Tien hanh thi nghiem
Bo tri 1 16 nuac bien lam 16 d6i chiing, va ciing vai cac 16 sinh vat kiem djnh khac nhau.
Thi nghiem kiem djnh tren cac sinh vat dugc thyc hien vai 3 mau lap (doi voi nuac) va 5 mau lap (d6i vai mau NCTT). Mgi thi nghiem dugc thyc hien trong phong thi nghipm on djnh nhipt dp (25 ± 1°C). Ngoai ra, m6i dgt thi nghiem co bo tri cac 16 thi nghipm vai chat co dpc tinh tham khao K2Cr207, {reference toxicant).
Kiem dinh doi vdi suphat trien sinh khoi ciia tao C. muelleri
Tao dugc dua vao kiem djnh trong 100ml nuac chiet tram tich (NCTT) dyng trong binh tam giac 250ml, sao cho mat dp tao ban dau a cac binh thi nghiem la 10 tb/ml va vai thai gian thi nghiem la 96 gi<r. Trong qua trinh thi nghiem, cac binh thi nghiem deu dugc dimg chieu sang lien tuc 24h vai cuong d6 anh sang trang la 38001ux. Ngoai ra, cac binh thi nghiem deu dugc cung cap mpt lugng dinh duong ban dau (ke ca mau doi chimg va fren chat dpc tham khao) de giiip tao phat trien ma khong bj thieu dinh duong. Mat dp tao dugc dem duai kinh hien vi vai bu6ng dem hong cau de xac djnh mat dp tao sau ciing.
Kiem dinh suphat trien phoi - du triing cau gai Diadema setosum:
Cau gai dye va cai dugc kich thi'ch phong tinh friing va de trirng bang dung djch KCl (10%), kiem tra chat lugng trimg va sau do cho thu tinh trong c6c thuy tinh. Thi nghiem keo dai frong khoang tir 4 8 - 72gia, khi quan sat thay a trong mau d6i chimg vai khoang 96-99% cac au triing da chuyen sang ^iai doan co gai dau thi ket thiic. Lac deu, dimg pipet hiit 10ml cho vao 6ng nghiem thiiy tinh r6i tien hanh ham formol 5%. Sir dyng kinh hien vi vai bu6ng dem de dem xac djnh s6 lugng au trimg binh thuong va dj thuong trong mau.
Kiem dinh tren vem xanh
Vem xanh dugc lya chpn sau do tha vao be vai s6 lugng 10 con/be, va thyc hien vai 5 mau lap, 01 mau d6i chimg va 01 mau chat dpc tham khao K2Cr207. Cac be thi nghiem dugc kiem tra nhipt dp, pH, dp man, oxy boa tan va kiem tra so lugng vem song - chet hang ngay. Thi nghipm dugc keo dai frong 96h va vai thcri gian chieu sang la ngay - dem (12h/12h)
4. Phan tich va xur ly so lipu: S6 lipu dugc th6ng ke va phan tich fren phan mem Microsoft Excel va Toxcal. Th6ng ke va tinh toan phan tram tren Microsoft Excel
Anh huang dpc tinh ciia mau thi nghipm d6i vai toe dp sinh truong ciia tao dugc tinh bang phan fram ire che (1) phat trien sinh khoi ciia tao theo cong thirc sau:
I%= (C - T ) x l O O / C (1) Trong do: I: la % ire che phat frien sinh khoi tao (inhibition)
402 Tuyen t?p HQi nghi KHOA HQC TOAN QU6c VE SINH HQC BifeN VA PHAT TRI^N B E N VCTNG
C: mat dp tao a 16 d6i chung,
T: mat dp tao a 16 mau kiem djnh (NCTT)
Phoi - Au trimg ciu gai: Tinh toan gia trj phan fram ciia au trimg phat trien khong binh thuong (PTKBT) frong thi nghipm kiem djnh theo cong thiic sau:
L(%)= Uk*100/Ut (2) Trong do: L: Phan fram gia frj au trimg khong binh thuong
Uk: Trung binh so au trimg khong binh thuong bat gap a cac mau lap U,: T6ng s6 ku trung binh thuong va khong binh thuong frong mau.
Anh huong d6i vai vpm xanh dugc tinh bang ty Ip (%) vpm s6ng/chet tai cac 16 thi nghipm Ngoai ra, chiing toi con sii dyng mpt so tai lieu nhu: Quy chuan ky thuat quoc gia ve chat lugng nuac ven ba QCVN 10:2008/BTNMT va Huong dan vS danh gia chSt lugng tram tich bien do Canada de xuat CCME EPC-98E va huong dan danh gia chat lugng moi truang nuac va fram tich cua Canada ve bao vp thiiy sinh vat (Canadian Sediment and Water Quality Guideline for Protection of Aquatic Life -2001), frong vipc tinh toan cac chi so nguy ca ban djnh lugng
(RQ) va chi s6 SeQI frong danh gia chat lugng tram tich.
i n . KET QUA VA THAO LUAN
Cac ket qua ve kiem djnh doe t6 frong nam 2007 va 2008 cho ta thay ve sy anh huong dpc to ciia moi trucfng khac nhau fren tiing doi tugng sinh vat:
1. Doi vol tao don bao C. muelleri
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Hinh 2a. D6 thj v l phSn tram (%) ire c h i sinh tru-ang cua tao C. muelleri (doi v&i moi trimrig nifoc t^i dam Thi N^i)
Tieu ban: CONG NGHE SINH HQC B I E N VA M Q I TRLfONG 403
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Hinh 2b. D6 thj v§ phln tram (%) LPC ch§ phat trien cua tao C. muelleri (doi v&i NCTT tai dam Thj N^i)
Tir cac ket qua thi nghipm, chiing t6i tien hanh ti'nh toan ve anh huang dpc t6 cua cac mau nuac va NCTT len sy ire che sinh fruang ciia tao don bao C. muelleri. Phan tram (%) lic che phat trien sinh khoi ciia tao dao dpng giira cac diem thu mau vao nam 2007 (dao dpng tir 59.7 - 96.5%), va nam 2008 (dao dpng tir 55.6 - 100%). Trong khi a thi nghipm doi vai NCTT cho ket qua thap hon so vai trong moi truang nuac. Giira 2 dgt thi nghiem vao nam 2007 va nam 2008, deu cho thay co sy lic che d6i vai sy sinh truong ciia tao C. muelleri, tuy nhien ty le ire che anh huong CO xu huong gia tang a mpt s6 diem TN4, TN9, TNIO, TNI 1, TNI2 vao nam 2008 so vai nam 2007, frong khi a nhimg diem thu mau khac xu the lai ngugc lai (hinh 2a). Dieu nay rat co the lien quan den qua trinh 6 nhiem tai cac diem gan boat dpng cang la chii yeu, bai ket qua frong thi nghipm trong NCTT cung the hipn xu the tuong ty (hinh 2b).
Qua ty Ip lie che tren tao dan bao da chi ra tac dpng ciia m6i truang d6i vai sy phat frien sinh khoi tao (tryc tiep hay gian tiep) la anh huang len qua trinh quang hgp, giam kha nang phan chia te bao hoac ngan can sy hap thy cac mu6i dinh duong (Klaine va Lewis, 1999; Fargasova, 1997). Theo Walker, va cs., 2006, cho rang cac thyc vat phii du s6ng frong m6i truang nuac thuong la sinh vat nhay cam vai cac chat hoa hpc, va tac dpng thuong xay ra d6i vai he quang boa (can tra phan img trao d6i vai anh sang trong qua trinh quang hgp). Theo mpt so nghien ciru, d6i vofi tao silic Cylindrotheca closterium se bi ire che toan bp sy phat frien khi tiep xiic vai nong dp Cd la 5pg/l (CCME - Cd, 2001), frong khi vai tao C. muelleri sy ire chS 50%
phat tn8n sinh kh6i khi tiep xiic von nong dp As la 6.07 - 9.16 pg/1 (Le Lan Huang, 2002); va vai 6 nhilm hydrocarbon dau la > 0,125 mg/l (Hoang Trung Du, 2004); con vai cac chit diet CO nhu Diuron hay Iragol 1051 chi can vai 0.06 pg/1 da anh huong len sy quang hgp (giam kha nang quang hoa - AFv/Fm) cua tao Madracis mirabilis, vai thai gian tilp xiic chi trong vong 8h (Negri va cs., 2004).
404 Tuyln tap HQi nghi KHOA HOC TOAN QU6C VE SINH HQC BifeN VA PHAT T R I E N BfeN V O N G
Tuy nhien, frong thyc te a ngoai moi truang nuac va fram tich thi do la sy anh huong ca mot t6 hgp cac chat nhiem ban vai cac tuang tac qua lai dan den nong dp anh huong cung thay doi. Bai cac chat khi gin ket vai nhau se dan den lam thay d6i mire dp dpc tinh cua cac chat 6 nhiem. Tir do miic dp anh huong iirc che d6i voi tao se bien dpng m^nh va phy thupc vao timg vj tri thu mau, dieu nay thay dugc kha ro qua sy dao dpng ve ty Ip lic che d6i voi tao trong thi nghiem cua de tai. Ket qua da cho thay tai diem TN9, TNIO, TNI 1 (co xu the gia tang vao nam 2008) la nhimg noi boat dpng ciia tau be va cac chat thai xung quanh, va cung la nai co kha nang chju anh huong 6 nhiem ciia cac chat hihi co (dimg frong son v6 tau) va sy lie che nay con phy thupc rat Ion vao sy hien dipn ciia thanh phan chat dpc frong m6i truong.
2. Doi voi au triing cau gai den Diadema setosum
Xem xet ket qua thi nghipm d6i vai au trimg cau gai cho thay ti Ip phan fram (%) au triing phat trien kh6ng binh thuong (PTKBT) a cac diem thu mau bien dpng rat Ian: vao nam 2007 t^i cac diem TN4, TN5 (giira dam) co mire anh huong cao nhat (vai ti Ip gan 100% au trimg bj anh huong); ket qua vao nam 2008 cung cho thay ngoai cac diem tren con co them diem TNI, TN7, TN8, TN12 ciing co miic dp anh huong gia tang so vai nam 2007 (hinh 3a). Trong khi do ket qua thi nghiem doi vai NCTT cho thay tai cac diem TNI, TN2, TN3 ti Ip anh huong co Idn hon so vai cac diem khac (hinh 3b), tuy nhien ti le anh huong nho hon rat nhieu so vai frong moi truang nuac.
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Hinh 3a. Ty I? (%) l u triing phat trien khong binh thu'crng v§ kiem djnh dpc tinh ciia moi tru'crng nu>ac d i m Thj Nai d6l vai c l u gai Diadema setosum
Tieu ban: CONG NGHE SINH HQC BifeN V A MOI TRLfO^NG 405
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Hinh 3b. Ty Ip (%) §u t r u n g phat trien khong binh thu'O'ng v§ ki4m djnh dpc tinh cua NCTT tai dSrn Thj Nai doi vwi c§u gai Diadema setosum
Tuy nhien, cho den nay viec danh gia day dii ve tac dpng m6i truong ciia cac loai hoa chat noi fren doi voi cu the timg sinh vat thiiy sinh con rat it, dac biet la nhung anh huang ciia du lugng cac chat thai nguy hai. Cac ket qua kiem djnh dpc to ciia moi truang doi vai sy phat trien au triing cau gai da cho ta thay dugc phan nao mire dp tac dpng cua moi truang den loai sinh vat song phii du giong nhu cau gai a giai doan phat trien au trimg (song nhu mpt sinh vat phii du), va au trimg se tiep xiic tryc tiep vai m6i truang nuac la chii yeu. Trong giai doan phat trien au trimg cau gai n6i chung rat nhay doi vai cac chat 6 nhiem hiiai ca nhu thuoc frir sau, Tributyltin (TBT) va kim loai Cu va As hoa tan trong nuac. Theo mpt s6 nghien ciru cho thay, mire dp anh huang ciia ham lugng Cu d6i vai au triing cau gai 5. purpuratus vai EC50 la 14.2pg/l (Rosen va cs., 2008); va anh huong ciia As doi vai au trimg cau gai D. setosum vai EC50 dao dpng tir 0.42 - 0.56pg/l (Le Lan Huong, 2002). D6i vai ch§t hiru ca dpc hai nhu DDD, DDT, va TBT thi iu trimg cau gai nhay cam hon gap nhieu lan so vai nhimg loai sinh vat than mem khac. Gia trj EC50 d6i vai au triing cau gai S. purpuratus cua TBT la lpg/1; ciia DDD la 67.6ng/l (Roepke va cs., 2005); va chiing ta biet rang hau bet cac chat hiru ca nay thuong co ngu6n g6c tir cac boat dpng nong nghiep, c6ng nghiep dong tau thiiy,... (Yamada va cs., 1997).
Nhimg ket qua do d^c ve thanh phan TTS frong dam Thj Nai cho thay hien dien a frong ca moi truong nuac va fram tich, mac dii ham lugng chua vugt qua GHCP (theo QCVN 10:2008/BTNMT va CCME EPC-98E). Nhung khi sinh vat song tiep xuc vai tong hgp nhieu chat nhilm ban cimg liic a trong moi truang, se chju tac dpng Ion hon rat nhieu so voi mpt chit va anh hudng doi vai sy PTKBT cua au trimg cau gai no the hien rat ro rang va cu the ve ban chit tu nhien ciia moi fruang chiing dang song.
Tuyen tgp HQi nghj KHOA HQC TOAN Q u 6 c VE SINH HQC BI^N VA PHAT TRI^N BfeN V&u^
406
3. Doi vol vpm xanh Perna viridis
Ket qua thi nghipm fren vpm xanh Perna viridis cho thay t?i mpt s6 diem khao sat co ty j chet cua vpm > 50 % nhu la TNI, TN3 va TN5, con lai hiu hit la rat nho, frong khi do ket qu nam 2008 chi ra a 2 diem TNI va TN3, nhung ty Ip cung chua vugt qua 50%) (hinh 4a) (gia ^ 96h-LC5o ciia chat dpc tham khao K2Cr207 d6i vai vpm xanh co dao dpng tir 33.8 - 56.1^g/l]
Ket qua kiem djnh doi vai mau fram tich a ca 2 dgt khao sat the hipn miic dp anh huang ga
chet doi voi vpm co ty Ip la rat nho (hinh 4b). ^
100 80 60 40 ^ 20
0
Jl
@ Nam 2007 D Nam 2008
I
m
^^ ^ ^ ^^ 4^ <^^ <^^ ^^ ' ^ V W
Vi tri thu mlu
•i
Hinh 4a. Dd thj ti I9 c h i t (%) cua v^m v§ thi nghiem k i l m djnh dpc td cua moi trvd^ng
u
nu'ac ddi y(n v f m xanh Perna viridis tfii ddm Thj Nfii
100 80 - 60 - 40 20 H
0
•im
n J I L j n
m Nam 2007 n Nam 2008
• .!Ti^
• it'
^" ^-<^^ <^'^'<^'<^ <^^ ^^V^V^V^''
Vj tn thu mau
Hinh 4b. D6 thj ti If ch§t (%) cua vpm v§ thi nghiem kiem dinh dpc t6 ciia NCTT d6i v*' vpm xanh Perna viridis tai dSm Thj N§i
Tieu ban: CONG NGHE SINH HOC B I E N VA MOI TRLTCTNG 4 0 7
Ve mat ty nhien, vem la loai it dich chuyen, an lpc cac chat phii du, la limg trong nuac.
Mac dii ket qua kiem djnh tren vem xanh ciia de tai cho thay ti Ip vem chet frong cac mau nuac va NCTT thu a tai dam Thj Nai, nhung van can luu y mpt vai diem vao nam 2007 nhu TNI, TN3, TN5 CO ti le vem chet > 50% (tuong img doc tinh cua K2Cr207 a 96h - LC50 dao dpng frong khoang 33.8 - 56.1 pg/1). Vai cac dau hieu sinh hpc tren no da phan anhth6ngtin nhit djnh ve chat nhiem ban trong viing, bai vem xanh co the tiep xuc bj dpng va chju dugc vai mpt s6 loai 6 nhiem m6i truang, va da co mot so nghien ciru sir dung vpm nhu la mpt sinh vat chi thj dimg de quan frac sinh hpc "biomonitoring" n6ng dp nhiem ban cac chat hoa hpc nhu kim loai nang trong moi truong bien (Nicholson, 1999; Fung va cs., 2004; Nicholson va Lam, 2005;
Cardellicchio va cs 2008). Ngoai ra vpm con co kha nang ti'ch luy mpt so kim loai vao frong ca the frong qua trinh lpc nuac de lay thiic an, bori cac thanh phan kim loai hay cac chat hihi ca dpc hai thuong nam trong thanh phan hat vat chat la limg hoac hap thy bai sinh vat phii du frong nuac (Rainbow va Dalilinger, 1993; Cardellicchio va cs 2008). Sy tich luy cac chat hihi ca nay se ngay cang gia tang theo thai gian, va anh huang kh6ng nh6 toi sinh vat thiiy sinh song frong dam. Chinh vi vay, theo ket qua nghien cim cua Monirith va cs nam 2003, miic dp tich luy cac hgp chat TTS frong sinh vat tai mpt s6 virng ven ba Viet Nam cho thay ham lugng TTS frong cac mo te bao cua vem xanh Perna viridis cao hon gap nhieu lan so vai ham lugng do ngoai m6i truang s6ng cua chiing (trong do co ca mpt s6 mau vem xanh thu a trong dam Thj Nai)
Ngoai ra, de xem xet ve tinh frang ciia chat lugng moi truang nuac va fram tich, chung t6i tinh toan chi so nguy ea ban djnh lugng d6i vai cac chat nhiem ban (RQ) cho cac thanh phan chat 6 nhiem frong nuac va fram tich vai ket qua phan tich kim loai nang va thu6c trir sau nam 2007. Cac chi s6 RQ cho cac thanh phan TTS hp clo hthi ca trong m6i truong nuac va fram tich CO chi s6 RQ < 1, dieu nay cho thay hau het diem khao sat con nam trong miic kh6ng co nguy ca va CO the chap nhan dugc. Trong khi do, chi s6 RQ doi vai thanh phan kim loai nang tai mgt vai diem trong dam dang nam trong mire dp tir kh6ng co nguy ca den nguy ea thap d6i vai sy 6 nhiem bai cac thanh phan kim loai nhu Cu, Pb va Cd. D6ng thai, ket hgp vai sir dyng phan mem SeQI ver 1.0 diing frong tinh toan va danh gia chat lugng tram tich cho virng nghien curu th6ng qua chi s6 SeQI, day la chi s6 co dp tin cay cao khi no dugc tinh toan dya fren m6 hinh la t6 hgp toan bg gia trj ve n6ng dp tir don chat cho den nhieu chat ciia thong s6 nhiem ban nhu:
cac thanh phan kim loai nang va thanh phan TTS co hipn dien trong mau (CCME - 2001). Tir chi s6 SeQI da chi ra tinh frang m6i truang fram tich vao nam 2007 tai dam Thj Nai co chat lugng fram tich van dang frong tinh frang t6t, voi SeQI la 100.
Trong dieu kien ty nhien, co che de cac chat dpc phat tan vao m6i truang la thong qua cac chat trung gian, chung hau nhu kh6ng t6n tai a dang c6 dinh ma nam trong cac phiic chat rat kho CO the do tim bang cac thiet bj don gian va thong thuong (Walker, va cs., 2006). Bai vay, de co dugc miic do tin cay trong danh gia chiing t6i da dong thai sir dyng ket qua ciia ca 3 thi nghipm kiem djnh de xem xet mire dp de dpa va nguy hai d6i vai chiic nang hp sinh thai, vai cac sinh vat CO dp nhay khac nhau nhu tao don bao — > au trimg cau gai > vpm xanh, diing de do dac va danh gia hieu img sinh hpc bai cac tac dpng. Vai chi s6 sinh hpc dimg xem anh huong ciia moi truong doi vai sinh vat nhu sy lie che phat trien, ti Ip chet hay nguong gay chet (LC50 hay LC95) rat hihi ich cho viec danh gia nhimg hau qua hay dy bao anh huong co the xay ra d6i vai sinh vat thiiy sinh do tac nhan 6 nhiem m6i truang gay ra (Chapman va cs, 2001, Cheng Liu va cs 2003).
Tir do xay dyng phan chia thang bac dya vao gia frj ty le % sinh vat bj anh huong se cho ta de nhan thiy nhit vl dpc tinh ciia m6i fruang (Chapman, 1989 va 2002) . Dya vao cac s6 lieu kilm djnh fren sinh vat ve mire dp ire che (%) tren tao, va % au trimg cau gai phat frien kh6ng binh thuong de tir do co the phan chia thang bac ve nhung anh huong ciia chat lugng moi truang d6i vai doi s6ng thiiy sinh (bang 1).
408 Tuyln tgp HQi nghj KHOA HQC TOAN QUOC VE SINH HQC B I E N VA PHAT TRlEN B E N VCTNG
Bang 1. Phan chia thang bac va mu'c do dung d4 danh gia c h i t Iu'p'ng moi tru'ang dya vao cac thi nghifm kiem djnh (Chapman, 1989 va 2002).
Ty Ip % s i n h v?t bj anh hu-o-ng TifOS-IOOVo:
Tir 80 - 94 %:
Tif 65 -79 %:
Tif 45 -64 %:
Tif 0 - 44 %:
Tinh tr^ng
Rat xau Xau K6m Trung binh
T6t
Chia b$c
5 4 3 2 1
Ket qua ey.the danh gia thang bac tren mau nuac va NCTT doi vai tao don bao, au triing cau gai, va vpm xanh da cho ta thiy ve nhimg miic dp anh huong dpc tinh ciia moi truang song len timg loai sinh vat a cac diem khao sat la rat khac nhau. Tir do chiing toi de xuat huong siir dung t6ng cac gia trj ve thang bac danh gia frong ca 3 thi nghipm dimg xem xet ve mure dp nguy ca tai cac diem nghien curu (bang 2) dya theo timg miic nhu sau:
- Tir 1 - 5: Khong co nguy ca va chap nhan dugc - Tir > 5 -10: Nguy co sinh thai thap
- Tir > 10 - 15: Nguy co sinh thai cao
Tir hinh 5 nhan thay rang tai mgt s6 diem khao sat trong dam Thj Nai nhu TNI, TN3, TN4, TN5 va TN8 a ca 2 nam 2007 va 2008, m6i fruang nuac trong dam co mire dp nguy ca thap (trir diem TN5 da nam trong miic dp nguy ca cao). Trong khi do, ve m6i truong tram tich lai cho thay hau nhu cac diem nam trong miic kh6ng c6 nguy co (chap nhan dupe). Qua d6 thj cung nhan thay miic dp nguy ea tai cac diem TNI, TN3, TN4, TN5 giam dan vao nam 2008, nhung tai TN9, TNIO va TNI2 thi lai gia tang len frong m6i fruong nuac va TN4, TNIO, TNI 1 frong moi truong fram tich.
Bang 2. Thang bac ve anh hu'ang cua dpc td mdl tru'crng ddi v ^ i 3 sinh vat bien thi nghipm
Vj tri khao sat
Thang b^c cho MT nu-o-c
Tao Cau
gai
V^m xanh
T6ng
T h a n g bfic c h o MT Trdm tich
Tao Cau gai V^m
xanh
T6ng Nam 2007
TN1 TN3 TN4 TN5 TN6 TN8 TN9 TNIO TN11 TN12
4 5 3 4 4 3 2 3 3 2
2 2 5 5 1 3 1 1 1 1
3 3 1 3
9 10
9 12
6 7 4 5 5 4
3 1 1 2 3 2 1 1 1 3
5 3 3 4 5 4 3 3 3 5 Nam 2008
T N I 1 5 1 7 1 1 1 3
Tieu ban: CONG NGHE SINH HOC B I E N VA MOI T R U O N G 409
TN3 TN4 TN5 TN6 TN8 TN9 TNIO TN11 TN12
1 4 3 2 1 3 5 3 3
3 2 5 1 5 2 1 1 5
1 i 5 \ 1
7 i 4 7 i 9 ! 2
1
•
4 7 6 7 5 9
2
1 2 4 4 3
7 i 7 1 3 1 ! 1 1 6
4 4 3 4 6 6 5
1."; (A)
D nafn2C a n a f n 2 (
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V|«ri
(B) I n nim 2007
' a nSm 2008
0 - " - ^
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Hinh 5. Thang bac danh gia nguy c a sinh thai tai cac diem khao sat tai d i m Thi Nai (A): Moi tru'crng nu'ac; (B) Moi tru'crng t r i m tich
Mac dii cac chi s6 danh gia v6 nguy ca sinh thai dang con a mire thap, nhung do da it nhieu cho thiy mire dp anh huong tren cac doi tugng sinh vat bien, m|it khac chiing ta dieu biet rang cac chit nhilm bin c6 kha nang tich luy qua nhieu con duong (tram tich, day truyen thirc an,...).
Vai viec sir dung va irng dung cac diu hieu sinh hpc trong danh gia nguy co ve moi truong dugc xem CO tinh thuyet phuc va cung cap nhirng th6ng tin ve anh huong ciia cac chat 6 nhiem. Vi vay, ngoai nhirng kit qua tren can c6 khao sat them ve kha nang tich luy ciia cac sinh vat song trong dim d6i vai cac chat nhiem ban nguy hai, nham giam thieu nhirng anh huong tai sire khoe cpng dong.
IV. TAI LIEU THAM KHAO
1. Nguyen Tac An, Nguyen Hihi Huan, Hoang Trung Du, Nguyen Phi Phat, Nguyen Dire Huynh., 1998. M6t vai ket qua kiem djnh dpc tinh ciia dung djch khoan tren sinh vat bien.
Tuyln tap nghien ciru bien, so 8: Trang 233-249
2. Nguyin Tac An (chii tri). 2003. Hien trang nhiem ban m6i truang bien va nhimg djnh hudng khic phuc. Trong bao cao t6ng hgp dy an: Hgp tac nghien ciru xay dyng phuang an quan ly tong hgp dai ven bd khu vyc Nam Trung Bp Viet Nam, vai diem trinh dien viing ven bd biln tinh Binh Djnh. 96 frang
3. Hoan" Trung Du (chii nhiem), 2004. Bao cao de tai ca sd 2004: Nghien ciiu sir dyng chi s6 sinh thai de danh gia hieu img nhiem ban dau d6i vdi 2 loai vi tao Skeletonema costatum va Chaetoceros muelleri. Vien Hai duong hpc. 52 trang
4 1 0 Tuyen tap Hpi nghi KHOA HQC TOAN QU6c VE SINH HQC BifeN VA PHAT TRifeN B £ N VCngg ' }
.r
4. Hoang Trung Du (chu nhiem), 2005. Bao cao de tai ca sd 2005: Nghien cuu anh hudng Qf^i dau diesel (pha hoa tan) len loai vpm xanh Perna viridis. Vipn Hai duong hoc. ' ? 5. Ha Thanh Huong, 2007. Bao cao chuyen de: Hien frang m6i frudng virng ven biln tinjil
Binh Djnh. 11 frang ; 6. V6 Hai Thi va Hoang Trung Du (dong chu nhiem), 2006. Bao cao de tai ca sd 2006*
Nghien ciru danh gia 6 nhiem moi truong mpt s6 Cang bien Vjnh Nha Trang dya tren chitl lugng tram tich bang ky thuat kiem djnh dpc t6. Vipn Hai duong hpc. 62 frang i | 7. Phan Minh Thy (2003). Bao cao chuyen de: Kha nang urng dyng mo hinh xac djnh ngu^nf nang lugng ca sd, sire san xuat ciia vyc nude, chi so phii dudng va siic tai sinh thai ciia cdc^
vyc nude ven bd tinh Binh Djnh. Thupc dy an: Hgp tac nghien ciiu xay dyng phuang anf
quan ly t6ng hgp ddi ven bd Nam Trung Bp. 26trang | 8. Klaine, S. J, M. A. Lewis., 1999. Algal and Plant Toxicity Testing. p:163-184. In; |
Quantifying and Measuring Ecotoxicology Effetcs. I 9. American Public Health Association (APHA), 2005. Standard methods for the examination f
of water and wastewater. APHA, USA •'- 10. ASTM., 1994. A Generic Protocol for Conducting Tropical Acute Toxicity Test with Fish i
and Invertebrates.). ASEAN - Canada Cooperative Programme on Marine Science - Phase II (CPMS-II). 55 frang.
11. Canadian Sediment Quality Guideline for Protection of Aquatic life. CCME -2001. Water Quality Index 1.0, Protocol and User's Manual. 35frang
12. CardeUicchio , N., A. Buccolieri, A. Di Leo, S. Giandomenico, L. Spada., 2008. Levels of;
metals in reared mussels from Taranto Gulf (Ionian Sea, Southern Italy). Food Chemistry, '.
107: 890-896.
13. CPMS-II, 1998. A general protocol for conducting fropical acute toxicity test with fish and invertebrates. Asean - Canada cooperative Programme on Marine Science - Phase H.
55pages
14. CCME., 2001. Canadian Environmental Quality Guideline - Protocol for the derivation of Canadian Sediment Quality Guideline for the Protection of Aquatic Life. 32 frang
15. Chapman, M, P., K. T. Ho, W. R. Munns Jr, K. Solomon, M. P. Weinstein., 2002. Issues in sediment toxicity and ecological risk assessment. Marine Pollution Bulletin, vol 44: 271-
278 : 16. Chapman, P. M., 1989. Current approaches to developing sediment quality criteria. ;:
Environ. Toxicol. Chem., 8: 589-599. ? 17. EPA SW-846 (Cd-Room). Test Methods for Evaluating Solid Waste,
Physical/ChemicalMethod.(http://www.epa.gov/waste/hazard/testmethods/sw846
18. Fargasova, A., 1997. The effect of organitin compound on growth, respiration rate, and chlorophyll a content of Senedesmus quadricauda. Ecotoxicology and Environmental Safety, 37: 193-1998.
19. Fung, C. N., J. C. W. Lam, G. J. Zheng, D. W. Connel, I. Monirith, S. Tanabe, B. J.
Richardson, P.K.S. Lam., 2004. Mussel-based monitoring of frace metal and organic contamination along the East Coast of China using Pema viridis and Mytilus edulis.
Environment. Pollution, 127: 203-216
20. Grasshoff K., Kremling K., Ehrhardt M., 1999. Methods of Seawater Analysis. Willey- VCH. ISBN 3-527-29589-5. 600p.
•?
-neu ban: CONG NGHE SINH HQC B I E N VA M 6 | TRl/6'NG 4 1 1
21. Long, S. M., K. J. Ryder, and D. A. Holdway., 2003. The use of respiratory enzymes as biomarker of pefroleum hydrocarbon exposure in Mytilus edulis planulatus. licotoxicology and Environmental Safety, 55: 261-270.
22. Macfarlane, G. R and M. D. Burchett, 2001. Photosynthetic pigments and perocidase activity as indicator of heavy metal sfress in the grey mangrove, Avicennia marina (Forsk) Vierh. Marine Pollution Bulletin, vol 42, No. 3: 233-240
23. Negri, A. C. Vollhardt, C. Muelleri Humphrey, A. Heyward, R. Jones, G. Eaglesham, K.
Fabricius., 2004. Effects of the herbicide diuron on the early life history stages of coral.
Marine Pollution Bulletin, 51: 370-383
24. Nicholson, S., 1999. Cytological and physiological biomarker responses from freen mussel, Perna viridis(L.) fransplanted to contaminated sites in Hong Kong coastal waters. Marine Pollution Bulletin, 39: 261-268.
25. Nicholson, S., and P. K. S. Lam, 2005. Pollution monitoringin Southeast Asia using biomarker in mytilid mussel Pema viridis (Mytilidae: Bivalvia). Environment Intemational, 31: 121-132
26. Rosen, G., I. R. Duarte, D. B. Chadwick, A. Ryan, R. C. Santore, P. R. Paquin., 2008.
Critical tissue copper residues for marine bivalve (Mytilus galloprovincialis) and echinoderm (Strongylocentrotus purpuratus) embryonic development: Conceptual, regulatory and environmental implication. Marine Environmental Research, 66: 327-336.
27. Vo Hai Thi, and Le Hoai Huong, 1998. Acute toxicity of Asenic to Tiger Prawn (Penaeus monodon). In proceeding of the Fourth ASEAN - Canada Technical conference on Marine Science, Langkawi, Malaysia: p 94-97.
28. Walker, C. H., S. P. Hopkin, R. M. Sibly, D. B. Peakall., 2006. Principles of Ecotoxicology.
Taylor and Francis group, LLC. 315pages
29. Yamada, H., K. Takayanagi, M. Tateshi, H. Tagata, K. Dceda., 1997. Organotin compounds and polychlorinated biphenyls of liver in squid collected from coastal waters and open oceans. Environmental Pollution, 96: 217-226.
A P P L I C A T I O N O F T H E R E S U L T S OF T O X I C I T Y T E S T ON M A R I N E O R G A N I S M AS T H E E C O L O G I C A L RISK A S S E S S M E N T T O O L F O R
C O A S T A L A R E A OF B I N H D I N H P R O V I N C E Hoang Trung Du
SUMMARY
The paper is based on the results of study that were focused the toxicity test on three marine organisms such as phytoplankton species Chaetoceros muelleri, larvae-development of sea urchin Diadema setosum, and green mussel Pema viridis were exposure on waters and sediment samples that collected in coastal areas of Binhdinh province (case study in Thi Nai lagoon). The studies are applying toxicity testing were measured the effects of water and sediment contamination on three organisms. The results of study were showed the inhibition effects on C. muelleri growth rates (biomass) are high values (about 90-100%) in almost studied sites. Meanwhile, the affected on embryo-larval development processes are presented the highest values at TN4, TN5 sites (center of lagoon) with approximately 100% larval abnormality. For
•v
4 1 2 Tuyln tap HQi nghj KHOA HQC TOAN QU6c Vfe SINH HQC B I E N VA PHAT TRI^N B E N VONR •
the live/death proportion of green mussel test were only showed at TNI, TN3, and TN5 sites have contained higher 50%, but other study sites were lower. The results of mussel experiments I in 2008, were showed only two sites (TNI, TN3) have values > 50% (respectively, with K2Cr20 i in 96h-LC5o is ranged from 33.8 - 56.1 pg/1). The study is also used the index such as RQ, and!
SeQI- Sediment Quality Index, and association to use the data of toxicity test experiments for applying to assess the effect of envfronmental quality on biological, ecological processes and to implement the ecological risk assessment for coastal waters. Environmental waters and sediment in as a whole of Thi Nai lagoon have risk levels are variation between no risk to low risk level (excepted TN5 site is high risk level); and the frend of risk levels are reduction in the top of | lagoon area, but at the sites of lower lagoon (TNIO, TNI land TN12), the frends of risk levels I
were increased by following the temporal investigation from 2007 to 2008. '"*.|
Key word: Toxicity test, abnormal development, inhibition, risk assessment |
