HQI NGH] KHOA HQC TQAN OUOC Vfe SINH THAI VA TAI NGUYEN SINH VAT LAN THU 5
DANH GIA ANH HlTCTNG CUA CHAT LlTONG NlTOC
DEN Q U A N X A T H i r c VAT PHU DUVUNG BIEN VEN BOf MIEN TRUNG, VIET NAM
PHAM THJ MINH H^NH Vien Ca hgc.
Vien Hdn ldm Khoa hgc vd Cdng nghe Viet Nam Trong dieu kien kinh te bien ngay cang phit trien, vdi muc tieu phin dau den nam 2020 dua kinh te tren bien vi ven bien ddng gdp khoing 53-55% tdng GDP ciia ca nude (Nghi quyet sd 09-NQ/TW ngiy 9/2/2007 "Vl chien luge bidn Viet Nam ddn nam 2020), vin dk 6 nhilm bien hi?n dang dugc quan tam. Nghien ciiu nay sii dung 5 nam (2006-2010) sd lieu quan trie mdi trudng, nhim danh gii chit lugng nude va cac die trung sinh hgc quin the thyc vat phii du (TVPD) vimg bien ven bd khu vuc mi6n Trung eac tinh tir Quang Binh den Binh Dmh, gdp phin phuc vu cdng tic quin ly mdi trudng bien Viet Nam.
Ben cgnh dd, vdi vai trd quan trgng ciia thyc vat phii du trong chu trinh dinh duang, cac bien ddng ve sinh khdi TVPD se anh hudng den ngudn Igi thiiy sinh. Viec danh gii cic anh hudng cd the cd ciia cac yeu td chit Iugng mdi truang den sinh khdi thyc vit phii du, van de cdn it dugc nghien ciru, cung da dugc thuc hien.
I. PHU'O'NG PHAP NGHIEN ClTU 1. Khu vyc nghien ciru
Nghien ciru niy sir dung sd lieu ciia Trgm Quan trie vi Phan tich mdi Irudng Bien ven bd mien Trung, la Tram thudc mang ludi quan trie mdi trudng qudc gia [6]. Viing nghien ciiu la viing bien ven bd thudc cac tinh tir Quang Binh den Binh Djnh (hinh 1).
Sd lieu thu thip trong 5 nam tir 2006 den 2010, djnh ky 2 lan/nani vio miia khd (thing 3, 4) va miia mua (thing 8, 9), pha trieu cirdng va trieu kiet. Cac thdng sd do dac va phan tich bao gom: Mdt sd y6u td thiiy ly-thiiy hda thdng thudng (nhiet dp, do mgn, pH, DO, TSS), cic thdng so chat dinh dudng nita (NOj, NOj, NHj), phdt pho (tdng phdt pho); chat diep luc (chlorophyll a), mpt sd kim logi nang (Cu, Pb, Cd, Zn, Hg), asen, dau ma, tdng coliform, thanh phin loii va mat dp thyc vat phii du.
2. Phuong phip thong UQ
Phirong phap kiem dinh tuang quan Pearson dugc ip dung de \ac dinh mdi lien he tirng cap giifa mat dp tao Silic, tao Lam, tao Giip ciing nhu tdng mat do lao \di cac yen td ly-hda, cac chat dinh dudng va cac chat ddc hai trong mdi trudng nude bien.
HQl NGHI KHOA HQC T O A N Q U O C V £ SINH T H A I V A TAI N G U Y E N SINH VAT L A N THlJ 5
Q d n d a o T g 'nh Khanf
u6ng Sa htoa)
Mi- (07* Ui* UW
Hmh 1. Vi Iri cdc diem quan trdc moi trirang biin ven bd mien Trung
HOl NGHI KHOA HQC T O A N Q U O C V E SINH THAI VA T A I NGUYEN SINH VAT L A N THU- 5 Mdi tuong quan giiia 2 bien dugc phan logi thuan vi nghjch, mirc dd tuong quan phu thudc vao be s6 tuang quan (r) nhu sau: |r| > 0,8: Tucmg quan d muc mgnh, |r| = 0,6-0,8: Mirc tuang doi mgnh, |r| = 0,4-0,6: Miic trung binh, jrj = 0,2-0,4: Mire yeu va |r| <0,2: Khong cd tuong quan ho^c d miic rit ylu. Cdng thiic tinh tuang quan (r) cua hai bidn ddc lap X va Y nhu sau [8];
^ - - 7 ^ ^ ^ — (1) (n-l)s^Sj,
Trong dd:
- r: He sd tuong quan giij'a2 bienXvi Y;n: Sd sd hang ciia mau; x,,y,: Gii tri thir i ciia mau.
S^,S^,:BQ lech chuin ciia bien X va bien Y: s^ = Jcl , s = Ja]
cr', O"': Phuang sai cua bien X va bien Y, tinh bang cdng thirc:
n~\^ n-\~(
- X,y: Trung binh cgng mau X va trung binh cgng mau Y 3. Phuang phap tinh chi so sinh hoc
Chi sd da dang loai (Shanon Wiener-H') [3], su dung de dinh gii ciu triic quan xa sinh vgt, trong dd chii y den sd Iugng vi ci mat dp loii.
H =-Jp,InP-
dominance-D) uu the.
i;n.(n,-I)
Chi sd trdi Simpson (dominance-D) [4] la chi sd the hien mirc dp loai phong phu nhat trong miu, dgi dien cho loai uu the.
N ( N - l ) Trong do:
P = —^: Mirc dd phong phii tuang ddi cua mdi loii.
N
- n,: Sd cic the ciia loii tlui i, N: Tdng sd ca the cd irong mau; S: Tdng sd loii, H": Chi sd da dgng Ioai.
II. KET QUA NGHIEN ClTU
I. Dinh gii chat lugng nude bien ven bdmicn Trung giai doan 2006-2010
Kel qua quan trac cic thdng sd mdi trudng vimg bien ven bd mien Trung giai doan 2006- 2010 dugc tinh trung binh nam vi so sanh vdi gidi han cho phep (GHCP) theo Quy chuan Ky thugt Qudc gia vc chat Iugng nude bien ven bd do Bd Tai nguyen va Mdi trirdng ban hanh nam 2008 (QCVN 10: 2008/BTNMT).
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HQI NGH! KHOA HQC T O A N Q U O C V £ SINH T H A I V A TAI N G U Y £ N SINH VAT L A N THU 5
Kit qui quan trie cac thdng sd thuy hda nhu nhiet dd nude bien, oxy hda tan, dg mgn, dp pH, TSS, cic chit dinh dudng nita va phdt pho, tdng coliform va mgt sd kim logi nang nhu ddng, chl, kem, cadimi. thuy ngin vi asen deu nam trong gidi hgn cho phep theo quy chuin chat lugng nude bidn ven bd. Ty le N: P (tinh theo nguyen tii) hay cdn ggi la ty sd Redfield [2] 16: 1 dugc coi Ii ty le dinh dudng tdi uu cho sy phat trien cua thyc vit phii du trong mdi trudng bifin.
Khi ty le nay thay ddi vdi gii trj <16 thi nita dugc coi liyeu td gidi hgn vi vdi gii trj > 16 thi phdt pho dugc coi li yeu td gidi han cho sy phit trien ciia tao. Ket qua phin tich sd lieu cho thiy ty sd Redfield bien ddi trong khoing 1,17-196,07; trung binh 41,52±27,75; vdi 80,36% gia tri > 16. Nhu viy, phdt pho la yeu td dinh dudng gidi hgn cho sy phat trien cua quan the thirc vat phii du vimg bien nghien ciru.
Nong dd COD trung binh/nani d giai doan 2006-2010 trong nude bien ven bd bien d^i trong khoang l,54-6,94mg/L. Tai tit ca cic diem do deu cd ndng do COD trung binh nim virpt qua GHCP. Diem do xa nhat d khu vuc mien Trung, Cdn Cd nhin chung cd ndng do COD thap ban cac diem do khic. Tgi mdt sd diem do nhu Deo Ngang, D i Ning, Dung Quit vi Sa Huynh, ndng dp COD cd xu the giim trong giai doan nghien ciiu, cac diem do cdn Igi nhin chung khong cd xu the ro rang.
Ndng do dau trung binh trong nude bien bien ddi trong khoang 0,02-13,57mg/L. Ndngd?
nhd nhat quan trie dugc d diem do Cdn Cd, cao nhit d Dung Quit. Tai tat c i cac diem do, quanh nim deu quan trie dugc ndng do dau vugt QCVN ddi vdi chat lugng nude bien ven bd Dgc biet, ndng dg diu ting dot bien vio nim 2007, bien ddi tir 2,07-I3,57mg/L. Nguyen nhan do vu -tran dau khdng rd ngudn gdc rat Idn phat hien vao thing 2/2007, anh hudng den 20 tinh/Ihinh ven bien, chii yeu la cic tinh mien Trung vdi tdng lugng dau thu gom ten den han 1,7 nghin tin (theo Tdng cue Bao ve Mdi trudng).
2. Die trung ve thanh phan Ioai va mat do thuc vat phu du 2.1. Dgc tru-ng ve thdnh phdn lodi thirc vgt phu du
Da phan Ioai dugc tdng sd 144 loai TVPD thudc 19 hp, 4 bd, 3 ldp, 3 nganh (tao Silic, tao Giap va tao Lam). Trong do, tio Silic ludn chiem uu the ca ve sd lugng loai vi mgt dp, tiSp den ta tio Giap, tao Lam cd mat dp khdng dang ke, khdng xuat hien d nhieu dgt thu mau. Sd lugng loii tai eac diem do ehenh lech nhau khdng ding ke, nhieu nhit d Ddng Hdi vi Cdn Cd deu cd 103 loai, thap nhat d Dung Quat cd 95 loai (bing 1). Bien dpng thanh phan loai theo miia cd xu the phong phii han vio dot do miia mua (dgt 2) so vdi mua khd (dgt 1) trong tat ca cac nim va tai tat ci cac diem do.
Die trirng thanh phan loai thuc vat phii du vung bien ven bd mien Trung zl
Dilm do Deo Ngang Dong Hoi Con Co Tiiugn An Dd Nang Dung Quat Sa Huynh Quy Nhon
Tao Silic 83 (85,6%) 89 (86,4%) 89 (86,4%) 88 (87,2%) 83 (84.7%) 81 (85,3%) 87 (84,5%) 79 (82,3%)
Tao Giap 12(12,4%) 11 (10,7%) 12(11.7%) 11 (10.9%) 12(12,2%) 11 (11,6%) 11 (10.7%) 12(12,5%)
Tao Lam 2(2,1%) 3 (2.9%) 2 (1,9%) 2(1,9%) 3(3,1%) 3 (3,2%) 5 (4.8%) 5 (5,2%)
Tong so loai 97 (100%) 103 (100%) 103(100%) 101 (100%) 98 (100%) 95(100%) 103(100%) 96 (100%)
HQl NGHI KHOA HQC T O A N Q U O C V £ SINH THAI VA TAI NGUYEN SINH VAT L A N THU 5 2.2. Ddc trirng vi mat dp thuc vnt phii du
Mat dg thyc vat phii du (TVPD) viing ven bien miln Trung bien ddi vdi bien do rgng, 0-13.776 te bio/lit ddi vdi tao Giip, 0-13.333 te bio/lit ddi vdi tao Lam, 222-80.000 td bio/lit doi vdi tio Silic, tong mat dg tao bidn ddi tir 444 den 80.000 te bio/lit. Trong dd, tio Silic ludn chidm uu thS, tao Lam v i tao Giap cd mat do tuang duang nhau cung nhu nhieu miu khdng xuit hien.
K6t qua phin tich cho thay khdng ed xu the bien ddi ro ret ve mat dp TVPD theo miia.
I • ' " " " " I
on nnn i
!fl"^) .
- tang mat - tang diy Miu phSn tich
Hinh 2. Phdn bd mat do thirc vgt phii du theo Idng ihu mdu
Tuy nhien, phan bo mgt do TVPD theo ting nude lai kha rd ret vdi die trung tang mat cd mgt dp cao hon so vdi ting day, nguyen nhan Ii difiu kien sdng (nhiet do, anh sing, dp due, chat dinh duang) tai ting mgt thuan lgi hon ddi vdi ddi sdng TVPD so vdi tang day (binh 2).
3. Tinh toan cac chi so sinh hoc
Ket qua tdng hop tinh toan cic chi sd sinh hpc cho thay chi sd da dgng loii (H') bien ddi trong khoang 1,27 den 2,83 (trung binh 2,18±0,33) vi chi so trdi Simpson (D) bidn ddi trong khoang 0,07-0,39 (trung binh 0,15±0,06). Nhin chung gii trj cic chisd sinh hgc (H', D) tgi cac diem do la tuang doi ddng ddu, chi sd da dang Ioai (H') phan anh tinh chat da dang sinh hpc thyc vgt phii du tuang ddi thip tai khu vyc nghien ciiu, chi sd trdi Simpson (D) cho thay quin Ihe thyc vgt phii du tuang doi on dinh, khdng cd loii trdi, tinh ddng deu loii cao. Gii trj H' phan inh ca mirc do da dgng thinh phan loai va mat dg tao, tuy nhien bien thinh phan loii ddng
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HQI NGHI KHOA HOC T O A N Q U 6 C V E SINH THAl VA TAI N G U Y E N SINH VAT L A N THCf 5 vai trd chu yeu trong y nghTa phin inh tinh da dang sinh hgc cua chi sd nay. Ket qui tinh H' the hien sy phii hgp vdi cic phin tich ve sy bien dgng thanh phan Ioai giDa 2 miia di neu dtren. Cy thd, cd sy ehenh lech gii tri H' giu-a 2 miia vdi xu thd hai cao ban vao miia mua (dgt 2) so vdi miia khd (dgt 1). Mgt die diem ndi bit nira Ii gia tri H' cung phan anh miic do da dgng sinh hpc cao hon d tang mat so vdi ting day.
4. Anh hudng ciia chat tupng nude den mat dp va da dang sinh hpc thuc vat phii du Ket qui kilm djnh tuang quan Pearson giira mat dg tio va cac chi so sinh hgc vdi cac yU to chat lugng mdi trudng cho thay (bang 2).
Tirang quan giira cdc yeu to dinh dirang vd mat dr) sinh vdt phit du: Mat dg tio Silic cing nhu tdng mat dg tio cd mdi tuang quan thuan vdi ndng do nitrat vi tdng nita vd co trong khi khdng cd tuang quan cd y nghTa thdng ke vdi amoni, nitrit. Dieu nay cd the giii thich la do trong thinh phin tdng nita vd ca, nitrat chiem thanh phan Idn va nitrat chinh ii thinh phan dinh dudng tio de hap thu nhat. Ngoai ra, cung tim thay mdi tuang quan thuan giiJa mat dp tao va ndng dp silicat. ket luan niy phii hgp vdi nhin dinh ve tinh trgi cua mat dp tao silic trong tong mat do tao d khu vuc nghien ciru.
Tuang quan giira cdc yeu to thiiy hoa thdng thuang vd mat do sinh vgi phii du: Mat dp tao cd tuang quan nghjch cd y nghTa thdng ke vdi do man, dieu nay phan anh tinh chit cua khu virc nghien ciru la viing bien ven bd nai ma cac loai thuc vat phii du hau het la cic loai phan bd rpng thich hgp vdi su thay ddi ndng dg muoi, dinh duang phu thudc vao ngudn lyc dja, Ket qua kiem djnh tuong quan cung chi ra rang cd mdi tuong quan nghjch giiia mat dp tao Silic vdi nhiet d?
nude bien (r = - 0 , 3 6 3 m ; p < 0,01) vi tuang quan thugn vdi tio Giap ( r = 0,115 ; p < 0,01).
Tuang quan gifla mat do tao va nhiel dp la phii hgp vdi nhan dinh ve mat dp tio, tio Silic chiem uu the ve mat dg trong tdng mgt dp tio, vi viy cic mdi tuang quan li ciing chieu vi cd mu'c dp tuong quan tuang duang nhau. Mat khac, ket qui cho thay cd tuang quan nghjch giu:a nhi?[ dp vdi mat dg tio Silic va tdng mat dp tao trong khi iai cd tuang quan thuan vdi mgt dp tao Gi^p.
Nhan djnh nay cung phii hgp vdi cic nghien ciiu ve tic dgng cua nhiet dg mdi trudng nude den cic nhdm tio, trong dd tio Silic ua nhi?t do thap, tio giip uu nhiet do cao [5]. Anh sang la yeu td khdng the thieu cho hoat dgng quang hgp ciia tio. Chit rin la lii^ng (TSS) lam phan tan, hap thu, can trd qui trinh truyen anh sing xudng cac tang nude sau han, vi vay ma ndng dp chat ran la lirng cd nidi tuang quan nghjch, cd y ngliTa thdng ke ddi vdi mat do tio. Tuang quan nghich giua dp pH vdi mat do tao silic (r=-0,125, p < 0,05), tio Lam (r =-0,131, p < 0,05), tong m§t do tio (r = -0,142, p < 0,05) cd the do viec tao ra cac san pham mang tinh axit trong qua trinh phin buy cua tao [I],
Ddnh gid mdi luang quan giua mdi do tdo vd cdc chdt dgc hgi (dau ma va kim logi nang) tgi ting mat cho thiy cd tuang quan nghjch mirc dp ydu giira ndng do diu vi mat d$
tao Giap (r = -0,258, p < 0,01) cung nhu tao Lam (r = -0,302, p < 0,01). Tuy nhien Igi khong cd mdi tuang quan nao giua ndng do diu vdi tao silic, dieu nay cd thi do cau tgo vach te bao cd thim them Silic ciia nhdm tao nay giiip bao ve khdi tic ddng cua diu [9]. Ngoai ra, khdng xic dinh dugc mdi lien he giira cic yeu td dgc hai neu tren vdi thyc vgt phii du d khu vyc nghien ciiu.
H Q l N G H I K H O A H Q C T O A N Q U O C V E S I N H T H A I V A T A I N G U Y E N S I N H V A T L A N T H O 5
Bdng 2 Tuong quan Pearson giira mat dp tao va cac thdng sd chat Iugng mdi trudng
Yiuta
T y s o R e d f i e l d N h i ^ t d o D o m $ n TSS pH DO BODs COD NH4 NO3 NOJ
T 6 n g n i t o v o c o ( T N ) P0<
S1O3 T o n g d a u m o Cu Pb Zn Hg Cd As
Mat do tao Tao silic
0.163' -0.363"
-0.263"
-0,173"
-0,125*
0,003 -0.006 0.072 0,014 0,305"
0,030 0.179"
-0.096 0,462"
-0,014 0,112 -0.125 -0.053 0.153 -0,159 -0,113
Tao Lam -0,047 -0,006
•0.079
•0.080 -0,131*
0,123 0.106 0,047 0.021 0.001 -0,062 0,012 0,149 0,146*
-0,258"
0.081 -0.012 0.083 -0,164 0.006 -0.018
Tao Giap -0.054 0,155**
-0.117*
-0,004 -O.080 -0,034 0.003 -0.009 -0,015 -0,083 -0,051 -0,060 -0.021 0,087 -0,302"
-0,018 0,291 0,143 -0.003 -0.034 0,027
Tong 0,148*
-0,343**
-0.270"
-0,175"
-0,142*
0,019 0,013 0,071 0,019 0,290"
0,013 0.173"
-0,074 0,468**
-0,045 0,106 -0,115 -0.041 0.138 -0,163 -0110
Ghi chii: * Tuong quan c6 y nghTa d miic p = 0,05 (2 dudi), ** Tuong quan co y ngliTa a mirc p = 0,01 (2 duoi).
Trong sd cac thdng sd mdi trudng, chi cd do pH cd anh hudng den mirc do da dang loai H' (r=-0,128, p < 0,05) va chi so trdi D (r =-0,137, p < 0,05). Nguyen nhan cd thd do do pH lien quan tryc tiep den mdi trudng trao doi chit ciia tao. Cic thdng sd con lgi deu khdng cd inh hudng den hai die trung neu tren ciia quin the tao. Ket luan niy ciing phii hpp vdi mdt sd nghien ciiu trudc diy ve mdi tuang quan giOa chat lugng nude va chi sd sinh hoc tai vimg bien nhi?t ddi [7]. Nguyen nhin chu yeu la do mirc dp da dang vi mirc dp trdi ciia quin the tao biin phy thupc vio tdng hda cic yeu td chat lugng nuac cung nhu mgt sd yeu Id khac nhu anh sing, ddng chay, sdng, thiiy trieu... chii khdng chi dan giin phu thugc vao cac yeu Id chit lugng mdi tmdng rieng le.
HQl NGHI KHOA HQC T O A N Q U Q C V £ SINH T H A I V A TAI N G U Y E N SINH V A T L A N THQ- 5 i n . KET LUAN
Chit Iugng mdi trudng nude va cic die trung sinh hgc thuc vgt phii du viing biln ven bd khu vyc mien Trung da dugc nghien cuu thdng qua viec phan tich sd lieu quan trie 5 nim giai dogn 2006-2010. Doi vdi chit Iugng nude, cac chat d nhiem dang luu y Ii COD va diu md. Cac chi sd sinh hgc (H', D) tgi khu vuc nghien ciiru phin anh tinh chat da dang sinh hgc thuc vgt phii du tuong ddi thip, quin the dn dinh, khdng cd loai trgi. Da xic dinh duge anh hudng ciia mdt so thdng sd chat Iugng nude den mat dp TVPD. Kit qua nay rit cd y nghTa trong viec dy doan vk sinh khdi tio phu thudc vio sy thay ddi eua mdi trudng sii dung phuang phip thdng ke don gian. Mac dii viy, viec dinh gii inh hudng cua chat lugng mdi trudng din da dang sinh hpc tao se can cic nghien ciru toan dien hem, trong do bao gdm tdng the cac yeu td chit Iugng moi trudng, dpng lyc hgc bien ciing nhu dpng vat phii du.
TAI LIEU THAM KHAO
1. Bernard P., L. Antoine, L. Bernard, 2004. J. Ecol Model. 178: 295-311.
2. Redfield B.C., 1958. Am. Sci 46'205-221.
3. Shannon C. E., Wiener, 1963. The mathematical theory of communications. Univ. Illinois, Urbana, 117 pp.
4. SimpsonE.H., 1949. Nature, 163:688-688.
5. Tao Li, Sheng Liu, Liangmin Huang, Hui Huang, Jiansheng Lian, Yim Van, Scnjle Lin, 2011.
Marine Ecology Progress Series, 424: 75-85.
6. Vien Ca hpc, 2006-2OIO. Bao cio tdng hgp kel qua quan trie mdi trudng bien miln Trung.
7. Yasser Abdul Kader Al-Gahwari, 2003.Thesis for the degree of Master of Science: Use of phytoplankton abundance and species diversity for monitoring coastal water quality. Universili Sains - Malaysia.
8. Thing ke trong kinh doanh. Tai lieu thuoc Chuong trinh dao tao thae sT quan tri kinh doanh quic te (MBA). 2009.
9. W. Scott Pegau (Oil Spill Recovery Institute). Biological Effects of Oil-in-ice in the Arctic.
(http7/\vww.pwsosri.org/business/0802advboardTab%203%20Stafi%20reports/3.4%20Biological%
20Effects%20of%20Oil%20in%201ce.pdf)
STUDY ON THE IMPACT OF WATER QUALITY TO MARINE PHYTOPLANKTON COMMUNITY IN THE CENTRAL AREA OF VIETNAM
PHAM THl MINH HANH
SUMMARY
Water quality and biological characteristics of phytoplankton in the central coastal region has been studied based on the five years monitoring data (from 2006 to 2010). For water quality, the main pollutanis are COD and oil and grease which had concentrations exceeded the standard values. Phytoplankton taxonomy analysis reveals that there were 144 species belonging to 19 families, 4 orders, 3 classes and 3 phylums. Biological indicators (H ', D) reflect that the phytoplankton biodiversity in study area was relatively low, stable population, there is no dominant species. Pearson correlation coefficients show positive correlation between the phytoplankton density and numbers of water quality parameters such as Redfield index, nitrogen and silicate nutrients and a negative couelation with other parameters' Temperature, salinity. TSS, pH and oil content. This result is valuable for predicting phytoplankton primary production depending on the change of environmental quality. Except for pH which could affect to the phytoplankton biodiversity and dominant, other water quality parameters on the other hand did not appear to have any particular influence on phytoplankton production. This conclusion requyres a more comprehensive study of the environmental quality, light condition, manne hydro-dynamic, zooplankton.. to the extent of phytoplankton biodiversity ofthe study area.
