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Tap chi Khoa hoc va Cong nghe bien T i l (2011) So 2 T r 35 47 KHA NANG ANH HlfOTVG CUA 6 NHIEM DAU DEN CAC RAN SAN HO 6 M O T SO K H U V U C V E N B I E N V I E T N A M NGUYEN DANG NGAI Vien Tai nguy[.]
Tap chi Khoa hoc va Cong nghe bien T i l (2011) So T r 35 - 47 KHA NANG ANH HlfOTVG CUA NHIEM DAU DEN CAC RAN SAN HO M O T SO K H U V U C V E N B I E N V I E T N A M NGUYEN DANG NGAI Vien T a i nguyen va M o i t r u o n g bien Tom tat: O nhung khu vuc nghien ciru (Hq Long, Cu Lao Cham, Phii Quoc) co nong dau ludn d muc cao, vuot gidi han cho phep (theo QCVN 10:2008) tie 1,3 den 19 lan Nhu vay, nhung viing bien da cd bieu hien cua su d nhiem dau vd tdc ddng true tiep den ddi sdng cua cdc sinh vdt thuy sinh Su suy giam sd luang loai, phu vd phdn bd cua san hd dd dien nhung nam gan day cd the cd lien quan den mice d nhiem dau Sau su cd trdn dau nam 2007 d khu vuc Cu Lao Cham, ndng dau nude cao len dot bien lam cho cdc ran san hd thay ddi hdn ve cau true, so luang loai vd phu Su suy giam cua san hd cung theo su bien thien cua ndng dau nude, d nhitng khu vuc gan cdng, ben tau ndng dau cao, phii san hd giam; cang xa cdng, ndng dau cang giam dan, quan xd san hd cd xu the tot hem i MO DAU Tu dugc phat hien den nay, dau mo da va dang la nguon nguyen lieu vo cung quy gia cua moi Quoc gia noi rieng va toan nhan loai noi chung Ngay san pham ciia dau mo dang co mat hau het cac linh vuc doi song sinh hoat hang ciia ngudi cung nhu hoat ddng cac nganh cdng nghiep Theo sd lieu thdng ke thi cd khoang 65 ddn 70% nang luong dugc sii dung tir dau md, chi cd khoang 20 den 22% tir than, den 6% tir nang luong nude va den 12% tir nang lugng hat nhan (Ngo, 2010) Viec tham dd va khai thac dau da va dang dien manh nhat 1-2 thap ky qua nhu cau nang lugng cang tang, nguon dau md cang can kiet Ddng hanh vdi viec khai thac la cdng doan van chuyen dau den cac nha may loc dau va den noi tieu thu Qua mdi cdng doan thi nguy co gay su cd tran dau ngoai y mudn ciia ngudi thudng xay va gay d n h i l m mdi trudng Cac phuong tien tieu thu dau hoat ddng tren bien ciing lam d nhiem mdi trudng nghiem dac biet la nhung phuong tien cd cdng nghe lac hau, qua nien han sir dung Cd the may rd nhat tai cac ben cang, ben tau noi tap trung sd lugng tau thuydn Idn, cac vang dau ndi tren mat nude theo ddng chay, gid phat tan khip noi cang lam tang dien tich d nhiem Viet nam mdi nam xay den gan chuc vu tran dau tren bien gay thiet hai to Idn ve vat chat va mdi trudng, siic khde ngudi, 35 cay trong, vat nuoi Tuy nhien nhung thiet hai den cac he sinh thai dudi nuoc thuong it dugc chu y v i nhung bieu hien ciia chiing khong r5 rang va kho nhin thay, nhung nhung hau qua de lai rat Ion va keo dai K h i su co nhiem dau xay dau se noi tren mat nude gay can trd su trao doi giua nuoc va khong lam moi trudng nude trd nen thieu dxy ddng thdi dau cdn gay ddc cho cac loai sinh vat dudi nude dan den chiing b i chet nhanh chdng Cac loai nhay cam nhu san hd rat de bi tac ddng chiing khdng cd kha nang di chuyen, dac biet d nhiem dau vao luc thap trieu, dau se bam true tiep len san hd nen miic tac ddng Idn hon rat nhieu Trong ndi dung bai bao nay, tac gia se trinh bay mdt phan ket qua nghien ciiu ciia de tai "Xay dung ca sd khoa hoc, phdp ly cho viec danh gid vd ddi boi thudng thiet hai nhiem dau gay tren viing bien Viet Nam" ve tac ddng ciia d nhiem dau den cac ran san hd viing bien nude ta II DIA DIEM, TAI LIEU VA PHlTCfNG PHAP NGHIEN CUTJ Dia diem va tai lieu nghien cuu Dia diem Be nghien ciiu kha nang anh hudng cua d nhiem dau den cac ran san hd, khu vuc dugc lua chon deu cd cac ran san hd phat trien va dai dien cho ca mien Bac, Trung, Nam la vinh Ha Long (Quang Ninh), Cii Lao Cham (Quang Nam) va Phii Qudc (Kien Giang), ddng thdi cac khu vuc deu cd cac ben cang, sd lugng tau thuyen hoat ddng nhieu hoac thudng xuyen chiu anh hudng ciia su cd tran dau (hinh 1) Tai lieu Bao cao dugc hinh tren co sd thu thap va x u ly cac ket qua nghien ciiu ve san hd va ran san hd tai cac khu vuc nghien cuu tir trudc den cua Vien Tai nguyen va M d i trudng bien, Vien Hai duong hoc Nha Trang va W W F va cac ket qua khao sat nam 2009 va 2010 ciia tai cac dia diem neu tren 36 Phuong phap khao sat ngoai hien t r u o n g Cac mau dau ma duac thu theo mat cat tir noi phat tan (cang, ben tau ) xa (theo su phan bo cua san ho), mau duoc lay tang mat va day, dugc co dinh va bao quan lanh, phan tich bang may quang ph6 kg DR/2000 (HACH, USA) Ap dung cac phuong phap khao sat ran san ho da dugc su* dung rong rai tren The giai nhu khung dinh lugng, mat cat diem (Reefcheck) Trong qua trinh dieu tra thu mau da su dung cac thiet bi lan Scuba thu mau a sau tai tren 15 m Dung may quay phim , may chup anh ngam de ghi lai nhung hinh anh cua tat ca nhung sinh vat song tren ran INmung loai kho xac dinh dugc thu mau va phan tich phong thi nghiem Phuong phap nghien cuu phong t h i nghiem - Tren co so cac tai lieu thu thap dugc tap hgp cac ket qua nghien cuu co lien quan, sir dung bien phap so sanh theo cac diem thai gian - Cac mau vat, hinh anh thu dugc cac chuyen khao sat dugc phan tich dua vao tai lieu phan loai san ho song cua Veron (2000) va cau tnic bo xuong ciia Veron et al (1976, 1977, 1980, 1982, 1984) - Xac dinh miic dp tac dong ciia dau len ran san ho, dua tren co so so sanh miic dp bien doi nong dp dau nuac tuong quan vai miic dp phat trien ciia ran - Cac so lieu hien truang va ket qua phan tich phong thi nghiem dupe xir ly tren cac phan men MS Excel, Word III KET QUA NGHIEN CUtJ Tac dong cua nhiem dau den ran san ho khu vuc Ha Long Khu vuc vinh Ha Long la nai co su nhiem dau kha cao, nguon gay nhiem chii yeu cac hoat dong ciia tau thuyen (tau du lich, tau van tai va tau khai thac hai san) dong thai khu vuc co cac cang b6c hang hoa, cang du lich va dac biet co cang xang dau B12 Nuac vinh Ha Long kem luu thong vdi mdi trudng bien bi bao boc che chin bdi g i n 2000 hdn dao, vay lupng dau rd ri mdi trudng tdn luu lau hon va kha nang khuSch tan vao mdi trudng nude va tram tich Idn han Cac ket qua khao sat va quan trie ciia Vien Tai nguyen va M d i trudng bien cac nam gan day tai khu vuc cho thay ndng dp d i u nude bien kha cao dac biet la khu vuc cang Cai Lan va vinh Cira Luc (hinh 2) Theo Quy chuin ciia Bp Tai nguyen va M d i trudng (QCVN 10:2008) gidi han cho phep (GHCP) ddi vdi ndng dp dau md nude bien ven bd bd la 0,2 mg/l Doi chieu 37 vai cac quy chuan cho thay moi truang nuac a day da bi n h i l m nghiem (cao gap tir - 12 lan GHCP), dac biet nhung khu vuc cang nhu cang Cai Lan, Cang xang dau B12 tir day phat tan toan vinh Cira Luc va vinh Ha Long _ 2.5 E 1.5 0.5 • Cai Lan B12 QraLuc IV Tram V Hi Long H i n h 2: Nong dau trung binh tai cac khu vuc vinh Ha Long va lan can (DC.Thung, 2009) Ket qua khao sat nam 2007, nong dau nuoc tang mat vung bien vinh Ha Long miia kho dao dong tir 0,07 - 2,01 mg/l, trung binh 1,04 mg/l, mua mua dao dong tir 0,07 - 2,32 mg/L, trung binh l,20mg/L, nong dau chenh lech giua hai mua khong Ion Nong dau nuoc thuong giam dan tir ba phia ngoai khoi, cao nhat gan cac ben cang la noi co mat dp tau thuyen cao (cira Luc 1,87 - 2,01 mg/l), thap nhat khu vuc Hang Trai, Cpc Cheo (0,13 mg/l) (hinh 3) Nong dp dau nuoc Vinh Ha Long cac nam tir 2008 d i n 2010 dao dong tir 0,32 den 0,75 mg/l So voi QCVN 10:2008, nong dp dau cao hon GHCP tir 1,6 den 3,7 lan Muc dp nhiem dau thuong duoc danh gia thong qua he s6 n h i l m (T ) day la ty n so giua nong dp dau nuoc va nong dp GHCP nuoc bien ven ba (0.2 mg/l) Theo so lieu thong ke, miic dp nhiem nuoc bai dau tang len theo thdi gian (bang 1), nam 1995, he sd d n h i l m bang 0,9 va cd xu hudng tang dan tir nam 1996 d i n nam 2010, dd nam 2007 cd he sd d nhiem rat cao (9,0) Nhu vay cd the thay ndng dp d i u nude bien khu vuc vinh Ha Long dang d miic bao ddng va cd xu the tang d i n theo thdi gian, d i l u cd cd nghia la mdi trudng nude cang trd nen d nhiem dau nang hon 38 E 1.8 1.6 1.4 1.2 0.8 0.6 0.4 0.2 Cua Luc Dau Go Ang Du Hang Trai Cgc Cheo Tram H i n h 3: Phan bo dau tir ven bd ngoai khoi khu vuc vinh Ha Long nam 2007 (nguon: DC.Thung 2009) Bang 1: He sd d nhiem dau trung binh nude bien Cira Luc Nam K h u vuc Cira Luc 1995 1996 1997 1998 1999 2000 2001 2007* 0,9 2,1 1,6 2,0 2,5 2,7 2,7 9,0 2010 3,7 ** (Ngudn: Tram quan trac quoc gia, *: DCThung 2009, **: DT O nhiem dau) Trudc nam 1995 cac hoat ddng cang, van tai, du lich chua phat trien khu vuc Vinh Ha Long cd ran san hd rat phat trien, phan bd rai rac hau khap quanh cac dao da viing vinh Cac ket qua nghien ciiu ve ran san hd d khu vuc cho thay ran san hd cd tinh da dang sinh hgc cao the hien qua miic dd phong phii ve sd luong gidng loai hien huu tai khu vuc Cd den 153 loai, 44 gidng, 12 hg san hd ciing va khoang 20 loai san hd mein va san hd sung duoc tim thay khu vuc (Yet, 1999) Tuy cac ran san hd d day khdng Idn dia hinh chia cat song chiing cd dd phu kha cao, cd 33,3% sd ran thudc loai tdt (dd phii san hd sdng tren 50%), 41,7% sd ran thudc loai trung binh (dd phii san hd tir 25 - 50%), va chi cd 25% sd ran thudc nhom ngheo nan (< 25%) 39 Cung v o i su gia tang cua muc nhiem dau tu nam 1998 trd lai day, cac ran san hd d khu vuc dang cang suy giam vd so luong loai, dd phu va pham v i phan bd Ket qua khao sat tai hien trudng va phan tich m l u vat duoc nam 2009 va 2010 tren toan khu vuc Ha Long chi cdn tim thay 102 loai, 32 giong thudc 11 ho cua bo san hd cung N h u vay, so vdi nhung nam trudc sd loai da bi suy giam den 1/3 (33%) Hien d khu vuc Ha Long khdng cdn ran nao thudc loai ran tot, chi cdn lai cac ran cd phu thudc loai trung binh den ngheo nan Nhin chung tren cac ran cd ty le da san hd chet rat cao, toan bo ddi mat bang tren t i t ca cac ran deu bi chit - noi cd kha nang tiep xuc vdi dau nhieu hon Nhu vay, cung vdi su gia tang ve cac hoat ddng du lich, cang, giao thdng thuy ndng dau nude bien khu vuc Ha Long cung cang tang Cd the de dang nhan thay ndng dau nude bien ty le nghich vdi su phan bd va da dang cua san hd theo khdng gian.Dac biet quanh cac khu vuc ben tau, cang, nhung noi tau thuyen hoat ddng nhieu cd ndng dau nude cao thi khdng cd san hd phan bd hoac san hd da chet nhu khu vuc Dau Gd, ven bd Bai Chay, Hdng Gai, Cua Luc Dau tac ddng cua dau den he sinh thai ran san hd bang nhieu co che khac nhu tao mang mdng phii tren mat nude ngan can su trao ddi giua nude va khdng dan den mdi trudng thieu dxy, cac sinh vat sdng mdi trudng khdng lay duoc oxy de thuc hien qua trinh trao ddi chat va chet K h i thiiy trieu nit dau bam true tiep tren be mat san hd lam san hd bi ngd ddc hoac sdc gay chet san hd Hoac ndng dau nude cao san hd se lien tuc tiet chat nhon de ngan can hoac dao thai dau bam vao chiing dan den chiing bi kiet siic va chet Ngoai dau ndng ddng dau nude cao, keo dai cdn lam anh hudng den qua trinh sinh san, tieu hda, tap tinh ciia san hd lam chiing khdng phat trien va chet dan Tac dong cua nhiem dau den ran san ho khu vuc Cu Lao Cham Ket qua khao sat vao thang 1/2008 cho thay ndng dp dau nude khu vuc Cu Lao Cham tai tang mat dao ddng h i 0,4 - 3,82 mg/l, trung binh 2,11 mg/l Tai tang day ndng dddau nude dao ddng h i 0,38 - 1,68 mg/l, trung binh 1,03 mg/l Neu so sanh vdi quy chuan chat lupng nude bien ven bd ciia Bp Tai nguyen va M d i trudng cho nude bien ven bo la 0,2 mg/l cho thay nam 2008 viing bien Cu Lao Cham da bi d nhilm d i u nang, tai t i n g mat vupt GHCP 10.5 l i n va t i n g day vupt GHCP l i n (Thanh 2008) He sd d nhiem dau nude thang 1/2008 so v d i nhung nam trudc tang len nhilu l i n Khi khdng cd su cd tran dau, miic dp d nhiem dau viing b i l n kha thip, he so d n h i l m dao ddng tir 0,1-1,8 , cd su cd tran dau he sd d n h i l m dao ddng tir 1,9 - 19,0, he 40 so nhiem dau tang cao gap 19 lan dieu chiing to nuoc d vung bien Cu Lao Cham bi nhiem dau nang (bang 2) Bang 2: He so nhiem dau tai mot so khu vuc d Cu Lao Cham (Thanh, 2008) K h u vuc thu mau 2002 2003 2008 Khu vuc Hdn M d 0.3 - 4.6 Khu vuc Hdn Giai 0.1 - 1.9 Khu vuc Bai Huong 1.3 1.8 6.7 Mat cSt I I 0.7 1.0 5.4 Mat cat I I I 1.2 0.4 19.0 Nhu vay cd the thay xu the ciia ndng dd dau nude bien Cu Lao Cham tang dan theo thdi gian, dac biet cao dot bien vao dau nam 2008 hien tuong dau tran khdng rd ngudn goc va dam tau gan h i nam 2007 Ciing thdi diem tien hanh khao sat tren ran san hd la Bai Bac va Bai Huong cho thay da cd su thay ddi Idn ve phan loai va cau tnic khu he Cac nam trudc ran bai Bac la mot cac ran dep nhat tai khu vuc Cu Lao Cham vdi su thdng tri cua cac loai san hd canh, dang ban Acropora phat trien manh trai dai va rdng khoang sau tir den 5m vdi dd phu len den 70 - 80% phia tren 0,5 - 1,5 m la su thdng tri ciia Montipora canh vdi dd phii 90-100% Tuy nhien lan khao sat nam 2008, cac tham san hd khdng cdn nvia ma thay vao dd la da san hd chet Sd luong loai thudc ho Faviidae tang len vdi nhieu tap doan dang khdi nhd phan bd rai rac ddi san hd chet ma trudc Acroporidae chiem uu the Phia chan ran cd nhieu tap doan Porites dang khdi Idn sdng chet xen ke, dudi nen day la su phd bien la san hd mem Ran Bai Huong khdng cd su thay ddi dang ke ve san hd mem nhung ddi san hd ciing mat giam di rat nhieu, tham san hd canh Montipora d dd sau 0,5 - 1,5 m da chet toan bd, cac tap doan sau hd khdi d dd sau - m ciing bi chet nhieu Hien tai ran Bai Huong cdn lai la quin xa san hd mem rat\phat trien d sau 4-8m Ket qua khao sat ciing cho thay ran Bai Bac cd ty le san hd sdng thap, chi cd 10% la san hd cung va 7,5% la san hd mem, dd ty le da san hd chet va da rat cao chiem tren 60% tdng hop phan day Ran Bai Huong cung tuong tu, hau nhu khdng cd san hd ciing (0,6%) dd hop phan da d ran rai cao chien den gan 1/2 San hd mem cd phii kha cao (20% hop phan day) (bang 3) 41 Bang 3: Do phu san ho va cac hop p h i n khac tai ran Bai Bac va Bai Huong (%) (Ngai, 2009) Ch4t day Bai Bac Bai H u o n g San ho cung (HC) 10 0.6 San ho mem (SC) 7.5 20.6 San ho moi ch§t (RKC) 0 Da san ho (DC) 20 5.0 Rong Ion(FS) 0 Hai mien (SP) 0 Da (RC) 40.6 48.7 Vun san ho (RB) 0.6 Cat (SD) 3.1 13.9 Bun (SI) 16.2 10.5 Khac (OT) 2.5 % phu 45 B Nam 1994 • Nam 2005 o Nam 2008 40 35 30 25 20 15 10 SH cung SH mem SH chet Da H i n h 4: Hop phan chat day tu nam 1994 den 2008 tai ran Bai Bac So sanh k i t qua khao sat phu lan v o i cac ket qua khao sat phii san ho cua W W F (1994) va Ngai (2009) cac nam 1994, 2005 va 2008 tai hai ran Bai Bac va Bai Huong cho thay co su thay doi Ion ve ty le % phu san ho song Hop phan san ho cung it di san ho chet, da va bim lai tang len, chi co san ho mem la tuong doi on dinh N h u vay co the noi su suy giam phii san ho d khu vuc da den miic bao dong (mat khoang 60% -80%) (hinh va 5) % phu 60 SH ciing SH mem SH chet H i n h 5: Hop p h i n chit day tai ran Bai Huong tir nam 1994 den 2008 Nguyen nhan dan d i n su suy giam co the lien quan den nong dau nuoc bien tang cao D i u nam 2007, doc ven bien Viet Nam da phat hien co nhieu vet dau loang t i p vao bd von cue, vung bien Cu Lao Cham la noi dau tien phat hien hien tuong sau d i n n h i l u dia phuong khac Mac du thoi gian khao sat da each thoi diem xay su cd tran d i u g i n nam nhung nong dau nude bien cua khu vuc van d miic rat cao, cao hon GHCP hang chuc lan Do vay tai miic da anh hudng r i t Idn den ddi song ciia cac sinh vat dudi nude, neu nhu luc xay su cd thi ndng dau nude chic chin cdn cao hon nhieu lan nua 43 Tac dong cua nhiem dau den ran san ho khu vuc Phu Quoc Ket qua phan tich mau thu dugc cac chuyen khao sat nam 2009 va 2010 tren cac ran san ho thuoc quin dao A n Thoi da ghi nhan dugc 86 loai thuoc 33 giong san ho cung, loai san ho thuy hie va loai san mem va san ho sung N h u vay so voi ket qua khao sat cua W W F (1994) thi s6 luong loai khong co bien dong nhieu chung to khu vuc co moi truong kha on dinh, dong thoi cong tac bao ve cua chinh quyen dia phuong ciing phat huy hieu qua kha tot thoi ky phat trien du lich lan va khai thac huy hoai tai nguyen nhu hien Cac ran san ho tai khu vuc A n Thoi kha tot, cac ran dugc khao sat truac day co 25% ran san ho tai Phii Quoc tinh trang tot, 58,3% trang thai trung binh va 16,7% ran san ho tinh trang xau (bang 4) Cac nhom loai bien dugc ghi nhan tren cac ran la Acropora, Pontes, Pavona, Montipora Bang 4: Dp phii san ho tai cac ran khao sat nam 2009 Hon Xudng Gam G h i Hon Thorn Hon Roi Trung binh San ho cung 50 67.5 28.7 52.5 49.7 San ho mem 0.6 1.2 0.5 0.6 San ho moi chet 0 0.2 Da san ho chet 6.9 0.6 6.2 5.7 Rong Ion 0 0 Hai mien 1.9 2.5 2.5 2.0 Da 16.2 8.1 40 17.5 20.4 Vun san ho 3.7 2.5 1.2 2.3 Cat 19.4 17.5 13.7 15 16.4 Bun 0 0 Cac nhom khac 1.2 1.2 6.2 1.5 2.5 Trong chuyen khao sat nam 2010 phat hien thay rat nhieu tap doan san ho moi chet van lp bp xuong trang, dong thoi co rat nhieu tap doan bi mat mau co nhung khoi san ho dang khoi Pontes duong kinh - m Day la rmung kh6i san ho co moi doi hang tram nam, chiing rat co y nghia viec tao cac tieu sinh canh cho sinh 44 vat bien tru ngu va nghien cuu co hau Ket qua khao sat lap lai tren mat cat co dinh tai ran cho thay ty le san ho cung giam gan 1/2 Hon Xudng va Hon Gam Ghi, san ho moi chet va da san ho chet co ty le cao va tang nhieu so voi nam 2009 (bang 5) Bang 5: Do phu san ho tai cac ran khao sat nam 2010 Hon X u d n g Gam G h i Hon Thorn San ho cung 29.375 36.875 25.625 San ho mem 0.625 0 San ho moi chet 8.75 5.625 4.375 Da san ho chet 15.625 11.875 25 Rong Ion 0 Hai mien 0.625 0.625 Da 26.25 10.625 28.75 Vun san ho 0 Cat 19.375 34.375 12.5 Bun 0 1.875 Cac nhom khac 0 1.25 Khu vuc quan dao A n Thdi la noi tap trung tau thuyen ciia ngu dan danh bat xa bd, tau thuyen du lich va cang hang hda vay luong dau rd ri mdi trudng bien kha nhieu Ket qua phan tich mau thu duoc vao thang 6/2009 tai khu vuc canh A n Thdi va ven cac dao thuoc quan dao A n Thdi cho thay khu vuc gan cang miic dd d nhiem dau cao hon GHCP laii, cang xa bo ndng dd dau cang thap di Trong dd khu vuc Hdn Dira (gan cang A n Thdi nhat) chi phat hien thay cd 15 loai san hd (sd luong loai rat thap), tiep den la hdn Roi cd 17 loai, cdn lai cac dao xa hon nhu Hdn Thorn, Hdn Xudng, Gam Ghi cd sd loai tir 31 d i n 49 loai Su bien ddng ve sd luong loai d day cd the lien quan den miic d nhiem dau ciia khu vuc IV KET LUAN - Tinh hinh d nhiem dau tai cac cang bien, ben tau vung ven bien Viet Nam ndi chung va tai khu vuc nghien cuu ndi rieng da den miic bao ddng Khdng chi d nhung khu vuc ven bd ma ke ca d rihung vung dao xa nhu Phii Qudc cung bi d nhiem bdi dau 45 Nong dau luon d muc cao tu 1,3 den 19 l i n GHCP V o i ndng do da anh hudng rat Idn den mdi trudng va ddi sdng cua cac loai thuy sinh vat nd; chung va san hd ndi rieng Nhieu loai sinh vat nhay cam cd the bi chet hoac di chuyen d i n noi khac lam xao trdn va' cd the gay mat can bang sinh thai khu vuc - Su suy giam sd luong loai, phu va phan bd ciia san hd da dien nhung nam gan day cd the lien quan den miic nhiem dau O khu vuc gan cang, ben tau, ndng dau rat cao, cang xa ndng dau cang giam dan san hd phan bd nhieu d nhung noi cd ndng dau thap va giam dan d nhurng noi cd ndng dd dau cao - Su suy giam ciia san hd rd nhat sau su cd tran dau nam 2007 d khu vuc Cu Lao Cham Ndng dau nude cao len dot bien hong cac ran san hd thay ddi han ve cau tnic, sd luong loai va dd phu TAI LIEU THAM KHAO Cue Hang hai Viet Nam, 2010 Du thao bao cao "Tinh hinh tac ddng mdi trudng ITnh vuc hang hai giai doan 2006 - 2010 va xay dung ke hoach giam t h i l u d nhiem giai doan 2011 -2020 N g u y l n Dang Ngai, 2009 Su suy thoai san hd Cu Lao Cham, nguyen nhan va tac ddng Tap chi khoa hoc va cdng nghe bien ISSN 1859-3097 Tr 250-261 Dinh T h i Ngo, 2010 Hda hoc md va d i u N X B Khoa hoc va K y thuat, 252 tr TrSn Due Thanh, Do Cong Thung va nnk, 2008 Dieu tra, khao sat danh gia thiet hai ve kinh te, mdi trudng va anh hudng den cac he sinh thai bien, d l xuit bien phap trudc mat va lau dai de phuc hdi mdi trudng cac khu vuc bi d n h i l m d i u tai Cu Lao Cham va Cua Dai (tinh Quang Nam) Bao cao de tai Luu tru tai Vien T N & M T B D6 Cong Thung va nnk, 2009 Nghien ciiu cac gia tri da dang sinh hoc vinh Ha Long phuc vu cho viec quan ly, phat huy gia tri da dang sinh hoc ciia D i san Bao cao tdng k i t d l tai Luu tru tai Vien T N & M T B Nguyen Van Tien, 2007 D i l u tra nguon loi san hd va tham cd b i l n Phii Qudc 2005 - 2007 T r a m Quan trac va Phan tich moi t r u o n g B i l n mien Bac, 2004 - 2010 Tap bao cao quy va bao cao tdng ket hang nam Tai lieu luu giu tai Vien Tai nguyen va Mdi trudng Bien 46 Vo Si Tuan va nnk, 2006 He sinh thai ran san ho vien Viet Nam N X N Khoa hoc va K y thuat 212tr WWF Vietnam Marine Conservation Northern Survey Team, 1994 Survey report on the Biodiversity, Resource Utilization and Conservation Potential o f Cu Lao Cham and Adjacent Islands, Quang Nam Da Nang Province, Central Viet Nam 10 WWF Vietnam Marine Conservation Northern Survey Team, 1994 Survey report on the Biodiversity, Resource Utilization and Conservation Potential o f A n Thoi Islands, Kien Giang Province, Viet Nam 11 Nguyen Huy Yet, 1999 Dieu tra, nghien cuu su suy thoai san ho d vung bien ven bd phia Bac, de xuat cac giai phap bao ve va phuc hdi Bao cao tdng ket de tai cap Vien K H & C N V N Luu tru tai Vien T N & M T B 12 Nguyen Huy Yet, Nguyen Thi Thu va nnk, 2010 Danh gia muc suy thoai cac he sinh thai ven bd bien Viet Nam va de xuat cac giai phap quan ly ben vung De tai cap Nha nude giai doan 2009 - 2010 EFFECTABLE OF OIL POLLUTION TO CORAL REEFS IN THE COASTAL A R E A S OF V I E T N A M NGUYEN DANG NGAI Summary: In the study areas (Ha Long, Cu Lao Cham, Phu Quoc) od concentration were high, exceeding the Vietnam 's Standard for coastal water (QCVN 10:2008) from 1.3 to 19 times Thus, these areas have been a sign of oil pollution and directly impacted on aquatic organisms The decline in the number of species, coverage and distribution of coral has occurred in recent years that may be related to oil pollution levels After the oil spill event in 2007 at Cu Lao Cham Islands, oil concentration in the water was suddenly high while the coral reefs seriously change in the structure, number of species and coverage The decline of coral reefs also varied following the oil concentration in water, in near port and harbor areas where oil concentration is very high and lower in the distant areas whereas coral reefs thrive in low oil concentration and decrease in areas with high oil concentration Ngay nhan bdi: 24 - - 2011 Ngudi nhan xet: PGS TS Do Cdng Thung 47 ... 4: Dp phii san ho tai cac ran khao sat nam 2009 Hon Xudng Gam G h i Hon Thorn Hon Roi Trung binh San ho cung 50 67.5 28.7 52.5 49.7 San ho mem 0.6 1.2 0.5 0.6 San ho moi chet 0 0.2 Da san ho chet... ty le san ho cung giam gan 1/2 Hon Xudng va Hon Gam Ghi, san ho moi chet va da san ho chet co ty le cao va tang nhieu so voi nam 2009 (bang 5) Bang 5: Do phu san ho tai cac ran khao sat nam 2010... ciia khu vuc IV KET LUAN - Tinh hinh d nhiem dau tai cac cang bien, ben tau vung ven bien Viet Nam ndi chung va tai khu vuc nghien cuu ndi rieng da den miic bao ddng Khdng chi d nhung khu vuc ven