Southeast Asian Fisheries Development Center Aquaculture Department
SEAFDEC/AQD Institutional Repository http://repository.seafdec.org.ph
Journals/Magazines Aqua Farm News
1996
Shrimps are part of a larger ecosystem
Aquaculture Department, Southeast Asian Fisheries Development Center
Southeast Asian Fisheries Development Center, Aquaculture Department (1996). Shrimps are part of a larger ecosystem. Aqua Farm News, 14(4-5), 20-21.
http://hdl.handle.net/10862/2435
Downloaded from http://repository.seafdec.org.ph, SEAFDEC/AQD's Institutional Repository
Shrimps are part of a larger ecosystem. Shrim p farm ing, like all other agriculture enterprises, requires natural resources -- land, water, and biological resources including seed and feed. B elow are the docum ented interactions betw een shrim p farm ing and the natural environm ent.
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In T h a ila n d , p o llu tio n o f w a te r s u p p lie s w ith c o n ta m in a n ts fro m industry, a g ricu ltu re , and se w a g e is th o u g h t to h a ve b ee n p a rtia lly re s p o n s ib le fo r s h rim p in d u stry lo s s e s sin c e 1989.S im ila r ca s e s in B a n g la d e sh , C h in a, Ind o n e sia , th e P h ilip p in e s.
2
In th e P hilip pin e s, s h rim p a nd m ilkfish c u ltu re is re sp o n sib le fo r re d ucin g the m a n g ro ve a re a fro m 4 4 8 ,0 0 0 ha in 1968 to 110 ,00 0 h a in 1 98 8. S im ila r c a s e s in T h a ila n d , M a la ysia , In d o n e sia .
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3 ,3 4 4 ha o f sh rim p p o n d s h ave led to sa lin a tio n of 1,168 ha o f a gricu ltu ra l la nd, m o stly ricefie ld s, in so uth ern T h a ila n d . In V ie tn a m , sa lt in tru sion h a s d a m a g e d 2 ,0 0 0 ricefie ld s in Ho C h i M inh C ity in 1991.
4
D e te rio ra tio n o f c o a s ta l w a te r q u a lity b e ca u se n m a n g ro v e s ca n filte r o r re m o ve su sp e n d e d so lid s, to x ic h y d ro ca rb o n s, a m o n g o th e rs. T h e e s tim a te d a re a o f R h izo p h o ra m a n g ro ve fo re s t th a t w o uld be re q uired to re m o ve th e n itro ge n a n d p h o s p h o ru s lo ad s p ro du ced d uring the o p e ra tio n o f sh rim p p o n d s is a s fo llo w s:N u trie n t R a tio (m an g ro ve :p o n d ) S em i-
in te n sive
In te n sive
N itro g e n 2 4 : 1 7.2:1
P h o s p h o ru s 2.8:1 21.7:1
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A n e stim a te d 10 kg o f fish a nd sh rim p la rva e a re killed d u rin g th e co lle ctio n o f 1 kg o f tig e r s h rim p p o stla rva e in W e st B en g al, India. U p to 5 ,0 0 0 p o stla rva e o f o th e r fis h e s a nd s h rim p s a re killed fo r e v e ry 100 m a rke ta b le p o stla rva e c o lle cte d in B an g lad e sh.
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T h e e ffe cts o f co asta l e u tro p h ica tio n and red tid e s on s h rim p c u ltu re h ave bee n e xtre m e ly s e r io u s , lik e in C h in a in 1 9 8 9 , w h e n a G y m n o d in iu m b lo o m a ro u n d B o h a i S e a ca use d an e stim a te d US $ 6 7 m illio n w o rth of d a m a g e to P e n a e u s c h in e n s is fa rm s.7
U se o f fre s h w a te r a qu ifers fo r in te n sive s h rim p fa rm s in T aiw an, th e P hilip pin e s, a nd T h a ila n d h a s re su lted in s a ltw a te r in tru sio n a nd s a lin a tio n o f fre s h w a te r a qu ife rs. A lso in B an g lad e sh a nd In d o ne sia .8
U se o f fre s h w a te r a q u ife rs by s h rim p fa rm s h a s resulted in s u b sid e n ce o f co a sta l land (a b o u t 0 .3 -2 m e te rs in the P in gtu ng co asta l a re a in Taiwan in 1 970-83).
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Wa ste s fro m sh rim p p on d s co n sist o f so lid m a tte r; a m ixtu re o f une ate n fo o d , fece s, p hyto pla n kto n , co lo n izin g b acteria; and d isso lve d m atter as a m m o nia, urea, ca rb on d io xid e , and pho sph o ru s.
A lso a m in o a c ids, p ro te in s, fa ts, ca rb oh ydrate s, fib er, m ine ra ls, a nd bacteria.
M a jo r cra sh es in the s h rim p in d u stry in Taiw an, P hilip pin e s, Indo ne sia , and C h in a h ave all been lin ke d to w a ste p ro du ction e xce e d in g th e a ssim ila tive c a p a c ity o f lo cal w a te r bodies.
1 0
L o s s o f m a n g ro v e fo re s ts h a s led to th e a c id ific a tio n o f p o n d w a te r and so il th ro u g h fo rm a tio n o f a cid s u lfa te so ils.1 1
S h rim p s h ip m e n ts h ave h elp e d th e sp re a d of p a th o g e n s like IH H N V (fro m P a cific Latin A m e ric a to A sia ) a nd M B V (fro m A s ia to H a w a ii, M e x ic o a nd Tahiti).
1 2
Intro d uctio n o f n e w s h rim p sp e c ie s a nd tra n s fe r o f s h rim p s w ith in th e ir n a tive ra n ge can brin g in d ise a se s a nd p ara site s, d is ru p t th e h ost c o m m u n ity th ro u g h c o m p e titio n , p re da tion a nd s tu n tin g , a nd ca use ch a n g e s in h ab itats, g e n e tic d iversity, a n d e ven co a sta l s o cio e co n o m ics.
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A n tib io tic re s id u e s can be e x tre m e ly p e rsiste n t in m a rin e s e d im e n ts a n d le ad to th e d e v e lo p m e n t of a n tib io tic re s is ta n c e a m o n g b a cte ria . U se o f o x y te tra c y c lin e in T a iw an, T h a ila n d , a nd th e P h ilip p in e s h a s re su lted in re s is ta n t s tra in s of Vibrio.
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In th e M e ko n g D e lta in V ie tn a m , lo ss of m a n g ro v e s h as in cre ase d vu ln e ra b ility to s to rm d a m a g e and c o a s ta l e ro sio n .
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F ish e rs in T h ailan d a nd B an g la d e sh re p orte d d e c lin e s in ca tch e s d ue to re stricte d a c c e s s to p re vio u sly a cce ssib le m a n g ro ve a re as.
O n e h e cta re of m a n g ro ve s ca n yie ld 7 67 kg of w ild fish and cru sta ce a n s, m o re th a n th e yie ld in e xte n sive s h rim p s y s te m s w h ich is u su a lly co n s id e ra b ly less th a n 500 kg p er ha p e r ye ar.
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C a tc h e s o f w ild tig e r sh rim p p o s tla rv a e h ave d e c lin e d in In d ia , B a n g la d e s h , a n d V ie tn a m . T h e re m a y b e n a tu ra l flu c tu a tio n s in a b u n d a n c e o f p o s tla rv a e , b ut o th e r a g g ra v a tin g fa c to rs in clu d e o verfishin g , p ollution, and h ab i
ta t d e s tru c tio n .
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S o m e d ru g s u s e in s h rim p c u ltu re like fu ra z o lid o n e and co m m o n ch e m ic a ls like m a la ch ite g re en a re p ote n tia l c a rc in o g e n s o r a lle rg e n s.1 8
L oss o f w ild s h rim p re s o u rce s by o ve rfis h in g , p o llu tio n , lo ss of h ab itat, re p re s e n ts lo ss of b ro o d sto ck a n d g e n e tic m a terial fo r fu tu re b re e d in g p ro gra m s.
CONCEPT M C a s ta ño s • SKETCHA S u rtid a / E L e d e sm a • REFERENCE MJ P hilip ps. 1 99 4. Shrimp culture and the environment. In: TU B a g a rin a o a nd EEC F lo re s (e d s). T o w a rds su s ta in a b le a q u a c u ltu re in s o u th e a s t A s ia and J a p a n . S E A F D E C A q u a c u ltu re D e p a rtm e n t, Iloilo, P hilip pin e s.
