liao 1986 aquacultural-engineering

7/28/2019 Liao 1986 Aquacultural-Engineering

1/15

Aquacultural Engineering 5 (1986) 219-233

G e n e r a l I n t r o d u c t io n t o th e P r awn Po n d S y s t e min Taiwan*

I-Chiu LiaoTungkang Marine Laboratory, Tungkang, Pingmng, Taiwan 92804, ROC

A B S T R A C TThe re ma rkable achiev em ents o f prawn cul ture in recent years inTaiwan have been widely recognized. In 1984, the annua l prod uct ion o fthe grass prawn Penaeus monodon alone reached 18000 tonnes ,m ak ing i t on e o f the mo st im portan t arid. fas tes t growing aquac ul tureitems. Its pro du ction is sti l l increasing an d i ts imp orta nce will con tinueto grow in the com ing years .

When considering th e progress o f prawn culture, aquacul tureengineering pro ble m s suc h as p on d construction, water inlet an d outletsystems, an d aeration system s are o f great concern. A n introdu ction topraw n po nd construct ion an d accessory e quip m ent in Taiwan is g iven,and a com parison wi th the representat ive prawn po nd sys tem s in Japanand Hawaii i s made. The present problems faced in these areas andpos sible so lution s are also discussed.

INTRODUCTIONThe prawn culture industry in Taiwan has been highly praised byaquaculturists around the world. The most important and popularpenaeid prawns under culture in Taiwan are grass prawn P e n a e u sm o n o d o n ; sand shrimp M e t a p e n a e u s e n s i s ; kuruma prawn Pj a p o n i c u s ; and red-tail prawn R p e n i c i l l a m s . Taking grass prawn as anexample, its annual pro ducti on recenth" exc eeded 18 000 tonnes(Chiang and Liao, 1985)and it has been widely recognized as one of*Contribution B No. 34 from the Tungkang Marine Laboratory.219Aquacultural Engineering 014 4-8 60 9/86 /S03 .50 -- Elsevier Applied ScienceP u b l i s h e r s L t d . E n g l a n d . 1 9 8 6 . Printed in Great Britain


2/15

220 l-Chiu Lmo

the mos t su i t ab le p rawn spec ies fo r cu l tu r ing (L iao , 1981 ; L iao andC h a o , 1 9 8 3 ) . B e c a u s e t h e ~ a s s p r a w n h a s b e e n c u l t u r e d l o n g e r i nT a i w a n t h a n i n a n y o t h e r c o u n t r y , t h e e x p e r i e n c e a c c u m u l a t e d h e r em a y b e t r a n s f e r a b l e t o o t h e r s i t u a t i o n s . B e c a u s e o f t h i s , T a i w a n w i l lp l a y a v e r y i m p o r t a n t r o l e i n t h e f u t u r e o f g r a s s p r a w n c u l t u r e i n t h eres t o f the w or ld .

T h e r e a r e s e v e r a l r e a s o n s f o r t h e f l o u r is h i n g s u c c e s s o f t h e p r a w ni n d u s t r y i n T a i w a n . T h e e s t a b l i s h m e n t o f l a r v a l r e a r i n g t e c h n i q u e s t os u p p l y a ll o f t h e l a r v a e n e e d e d a t a r e a s o n a b l e p r ic e , th e d e v e l o p m e n to f m o r e t h a n 2 8 b r a n d s o f i n e x p e n s i v e , c o m m e r c i a l l y a v a i la b l e f o r m u -la ted d ie ts , the fa rm ers ' d i l igen t, ha r d w ork a nd the resea rch ers ' e f fo r tsa r e j u s t s o m e o f th e m . D e s p i t e a l l o f t h e s e a c h i e v e m e n t s , p r o b l e m s s ti lle x i s t . T h e i n c r e a s e i n s t o c k i n g d e n s i t y h a s r e s u l t e d i n m o r e p r a w nd i s e a s e s . T h e c o o r d i n a t i o n o f s u p p l y a n d d e m a n d a t t h e m a r k e t h a sb e e n d if fi cu lt . T h e q u a l i t y o f m a r k e t a b l e p r a w n s n e e d s t o b e u p g r a d e dt o s u cc e s s fu l ly c o m p e t e i n th e i n t e r n a t i o n a l m a r k e t . A q u a c u l t u r ee n g i n e e r i n g i s l o o k e d u p o n a s a n i m p o r t a n t t o o l t o f u r t h e r t h ed e v e l o p m e n t o f t h e p r a w n i n d u st ry . T h e i m p r o v e m e n t s p o n d l ay o u t,p r o p e r c o n s t r u c t i o n , a n d e q u i p m e n t s e l e c t i o n c a n m a k e a r e m o s ts i g ni fi c an t . A n i d e a l ly d e s i g n e d a n d c o n s t r u c t e d p o n d h a s t h e a d v a n -tages o f be ing easy to opera te , l abor sav ing and ab le to p rov ide thep r a w n w i t h a n o p t i m a l l iv i n g h a b i t at . U n d e r s u c h a n e n v i r o n m e n t ,p r a w n s s h o u l d b e h e a l t h y a n d a c h i e v e r a p i d g r o w t h a n d h i g h s u r v iv a lr a t e s . T h e b u s i n e s s t h e r e f o r e c a n e n j o y a m u c h s m o o t h e r a n d m o r ep r o f i ta b l e o p e r a t i o n .I n o r d e r t o e s t a b l i s h t h e g r o u n d s f o r t h e f u r t h e r d e v e l o p m e n t o fp r a w n c u l t u r e i n T a i w a n , g r o w - o u t p o n d c o n s t r u c t i o n , h a t c h e r y e q u i p -ment , wa te r pumping , and in le t and ou t le t , a s we l l a s ae ra t ion se tup ,a r e s u m m a r i z e d . I n t e n s i v e g r o w - o u t p o n d s f o r c u l t u r i n g k u r u m ap r a w n i n J a p a n a n d a s u p e r i n t e n s i v e g r o w - o u t r a c e w a y f o r c u l t u r i n gb l u e s h r i m p P . s t y l i r o s t r i s i n H a w a i i a re a l s o i n t r o d u c e d f o r r e fe r e n c e.

D E V E L O P M E N T O F G R O W - O U T P O N D C O N S T R U C T I O NI n t h e e a r l y h i s t o r y o f p r a w n c u l t u r e i n T a i w a n s o m e 3 0 0 y e a r s a g o ,t h e r e w e r e n o w r i tt e n r e c o r d s o f p o n d c u l t u r e a n d h e n c e n o d e t a i le dd e s c r i p t i o n s c a n b e f o u n d t o d a y . J u d g i n g f r o m t h e s i m p l e , r o u g h ,t r a d i t io n a l p o n d s t h a t a r e s ti ll i n e x i st e n c e i n p a r t s o f S o u t h e a s t A s i a ,


3/15

General introduction to the prawn pond O,stem in Taiwan 2 2 1

t 1

J l- - l - - I

(ii)

(b)

(c)F i g . 1 . P r a w n g r o w - o u t p o n d s w i th m u d d i k e s , c e n t r a l d r a in a g e a n d s e g m e n t a lc u l t u r e s y s t e m . ( a ) T w o k i n d s o f m u d d i k e p o n d : ( i ) S i m p l e a n d r o u g h t r a d i t i o n a lp o n d , ( i i ) i m p r o v e d p o n d w i th w a t e r - g a te ; ( b) c e n t r a l d r a i n a g e p o n d ; ( c ) s e g m e n t a l

c u l t u r e p o n d .

t h e p o n d s h o w n i n F i g . l( a , i) is m o s t l i k e l y t h e t y p e w h i c h w a s o r ig i n -a l ly u s e d f o r t h e p o l y c u l t u r i n g o f s h r i m p , p r a w n s a n d f is h. T h e s eu s u a l ly i r r e g u l a r ly s h a p e d , m u d d i k e p o n d s o f t e n h a v e t re e r o o ts ~r o c k s a n d o t h e r o b s ta c l e s o n t h e u n e v e n b o t t o m . T h e p r o d u c t i o n o fp r a w n s d e p e n d e d o n m a n y u n c o n t r o l la b l e e n v i r o n m e n t a l fa c to r s a n dp e o p l e b e l i e v e d i t w a s l u c k w h i c h d e t e r m i n e d t h e h a rv e s t .

S h o w n i n F i g . l (a , ii ) i s t h e s l ig h t ly i m p r o v e d p o l y c u l t u r e g r o w - o u tp o n d f o r p r a w n s a n d m i l kf is h . S u c h p o n d s w e r e u s e d w i d e l y b e f o r e


4/15

222 l-Chiu Liao

t h e 1 9 6 0 s. T h e s u r f a c e a r e a o f t h e s e p o n d s w a s u su a l ly 1 - 3 h a , l a r g e rt h a n t h e p r a w n p o n d s u s e d i n m o r e r e c e n t y e a r s . T h e d i k e s o f t h ep o n d s a r e u s u a l l y m a d e o f e a r t h , b u t t h e i n n e r w a l l s m a y b e p a r t i a l l yo f b r i c k o r c e m e n t p l a ti n g . T h e s a m e w a t e r - g a t e i s u s e d f o r b o t h i n le ta n d o u t le t . T h e w a t e r s u p p l y a n d d r a i n a g e d e p e n d t o t al ly o n h i g h a n dl o w ti d es . D u r i n g t h a t p e r i o d o f p o l y c u l tu r e , t h e p r a w n w a s c o n s i d e r e da b y - p r o d u c t o f th e m i l k fi s h p o n d , a n d o n l y a f e w h u n d r e d k i lo g r a m so f p r a w n w e r e p r o d u c e d p e r h e c t a r e ( H u a n g , 1 9 6 9; L i a o a n d H u a n g .1973; L iao , 1981) . I t was no t un t i l 1968 , wi th the es tab l i shment o fla rva l r ea r ing t echn iques , tha t l a rge sca le p rawn cu l tu re becameposs ib le (L iao , 1981) . In the fo l lowing yea rs , ex i s t ing mi lk f i sh pondsw e r e i m p r o v e d b y i n c re a s i n g t h e w a t er d e p t h f r o m 3 0 - 4 0 cm to5 0 - 7 0 c m f o r u s e i n e x t e n s i v e p r a w n c u l tu r e . L o c a l l y a v a i la b l e s n a il s.s o y b e a n c a k e s a n d t r a s h f i s h w e r e i d e a l s u p p l e m e n t a l f e e d s . A s t o c k -i n g d e n s i t y o f 3 - 3 -5 p o s t - l a r v a e m - 2 w a s a d o p t e d a n d a s a ti s f a c t o ~ 'h a r v e s t o f 0 "5 - 1 ' 0 t o n n e s y e a r -~ w a s a c h i e v e d ( H u a n g , 1 9 6 9; L i a oa n d H u a n g , 1 9 7 3 ) .

S t a r t i n g i n t h e e a r l y 1 9 7 0 s , g r o w - o u t p o n d s b e g a n t o b e c o n -s t ruc ted espec ia l ly fo r p rawns . Be t te r des igned ponds o f 0"1-0"5 haa p p e a r e d i n t h e l a t e 1 9 7 0 s . Wa t e r d i s t r i b u t i o n s y s t e m s a n d a e r a t i o ne q u i p m e n t w e r e t a k e n i n t o c o n s i d e r a t i o n b y b i o l o g i s t s , d e s i g n e r s a n de n g i n e e r s . F i g u r e l ( b ) s h o w s t h e g r o w - o u t p o n d d e s i g n e d b y t h ea u t h o r i n 1 9 8 0 u p o n t h e r e q u e s t o f K u a n - F u p r a w n f a r m l o c a te d a tF a n g l i a o ( n e a r T u n g k a n g ) . T h i s d e s i g n w a s r e c e n t l y a d o p t e d b y t h eS a n M i g u e l C o r p o r a t i o n A q u a c u l t u r e C e n t e r , i n t h e P h i l i p p i n e s , w i t hsa t i s fac to ry resu l t s (L iu and Mancebo , 1983) . I t i s equ ipped wi th ac e n t r a l d r a i n a g e s y s t e m f o r g a t h e r i n g a n d e x p e l l i n g w a s t e . S t o c k i n gdens i t i e s a s h igh as 30 -4 0 pos t - l a rv ae m -2, su rv iva l ra tes o f 80% , andh a r v e s t s r e a c h i n g 8 - 4 - 1 1 .2 t o n n e s h a - ~ c r o p - ~ h a v e b e e n o b t a i n e df r o m t h is t y p e o f p o n d ( L i a o a n d C h a o , 1 9 8 3) .I n 1 9 8 1 , t h e a u t h o r d e s i g n e d a n o t h e r t y p e o f g r o w - o u t p o n d f o r th eT a i w a n S u g a r C o r p o r a t i o n i n t h e C h i a y i t i d a l l a n d s i n c o o p e r a t i o nw i t h r e s e a r c h e r s i n th e s a m e c o m p a n y . A s s h o w n i n F ig . 1 (c ), e a c h u n i to f th e p o n d s i s d e s i g n e d f o r s e g m e n t a l c u l t u r i n g a n d c o n s i s ts o f a s m a l lpo nd fo r P ,~-20 to juven i le s o f 2 g, a m ediu m s ized po nd fo r juven i le sof ~ g to abo u t 5 ,, and a la rge pon d fo r p raw ns o f 5 g to ma rke tab les ize . I t i s ve ry conven ien t to t ake advan tage o f wa te r cur ren t to sh i f tt h e p r a w n s f r o m o n e p o n d t o t h e n e x t a s th e y g r ow . M e a n w h i l e p o n db o t t o m s a r e m a i n t a i n e d i n a b e t t e r c o n d i t i o n b e c a u s e t h e p e r i o d o f


5/15

General introduction to the prawn pond ustern in Taiwan ] 2 3c u l t u r e in e a c h p o n d is s h o r t e n e d . T h i s w ill r e su l t m a h i g h e r s u ~ i v a lr a t e a n d f a s t e r g r o w t h r a te . S o m e d i s a d v a n t a g e s o f t h is W p e i n c l u d et h e f o ll o w i n g . ( 1) G r o w - o u t p o n d s w i t h a s u r f a c e a r e a o f 3 h a a r e t o ol a rg e to o p e r a t e e f f ic i e n tl y a s a n i n t e n s i v e sy s t e m . T h e o p t i m u m a n dt h e a c c e p t a b l e m a x i m u m s iz e n e e d s t o b e d e t e r m i n e d . (2 ) T h e l ar g e.r e c t a n g u l a r l y s h a p e d p o n d s a r e n o t s u i t a b l e f o r c e n t r a l d r a i n a g e . T h eo p t i m u m s h a p e a n d s i z e r a t i o s h o u l d b e f o u n d . S i n c e t h e s m a l l ,m e d i u m , a n d l a r g e p o n d s a r e a c o m p a c t u n i t , a n y c h a n g e i n o n e p a r tw i ll c a u s e c h a n g e s i n t h e o t h e r p a r t s . I n s u m m a r y , a f t e r c a r e f u l c o n -s i d er a ti o n , s o m e i m p r o v e m e n t s s h o u l d b e m a d e to t he w h o l e st ru c t u rein o r d e r t o d e v i s e a m o r e e f f ic ie n t p o n d f o r g r o w i n g p r a w n s .

D E V E L O P M E N T O F H A T C H E R Y C O N S T R U C T I O NI n 1 9 6 8 , w h e n t h e a u t h o r m a d e a m a j o r b r e a k t h r o u g h in t h e l ar v alr e a r i n g t e c h n i q u e s o f g r a s s p r a w n ( L i a o e t a l . , 1 9 6 9 ) , n o h a t c h e r ye q u i p m e n t w a s a v a il ab l e . T h e c o m m o n 0-5 o r 1 t o n n e r o u n d p l a st ict a n k s w i th fi at b o t t o m s w e r e a d o p t e d f o r h a t c h e r y a n d n u r s e r y u s e. A tt h e e n d o f s a m e y e a r , a p r e l i m i n a r y g r a s s p r a w n h a t c h e r y w a s s e t u pu n d e r t h e g u i d a n c e o f t h e a u t h o r . A w e l l i n s u la t e d b u i l d in g w i th c o n -c r e t e t an k s w a s c o n s t r u c t e d . T h e n e x t y e a r, a f o r m a l h a t c h e r y b u i ld i n gp r o v i d e d w i t h a h e a t i n g f a c i l i t y w a s e s t a b l i s h e d a t T M L ( T u n g k a n gM a r i n e L a b o r a t o r y ) a n d i t b e c a m e t h e f u n d a m e n t a l m o d e l f o r l a t e rh a t c h e r y c o n s t r u c t i o n ( F i g . 2 ( a ) ) . A p r a w n h a t c h e r y u s u a l l y c o n s i s t s o fo n e o r t w o r o w s o f c o n c r e t e t a n k s , e a c h w i t h a n a p p r o x i m a t e c a p a c it yo f 5 0 t o n n e s . F i g u r e 2 ( b ) s h o w s a n i m p r o v e d h a t c h e r y w i t h s e p a r a t eo u t d o o r t a n k s c o v e r e d w i t h P V C s h e e ti n g . T h i s h a s th e a d v a n t a g e o fe a s y m a n a g e m e n t , d i s i n f e c t i o n a n d c l e a n i n g . F i g u r e 2 ( c ) s h o w s t h el a d d e r s t y l e h a t c h e r y w h i c h i s e v e n m o r e f u n c t i o n a l a n d l a b o r s a v i n ga s it u ti li ze s d i f f e r e n t w a t e r l e v el s b a s e d o n t h e s l o p e o f th e g r o u n d .

A t p r e s e n t , t h e r e a r e m o r e t h a n 1 2 0 0 p r a w n h a t c h e r i e s in T a i w a na n d a t o ta l o f 1 .3 x 1 0 ~ p r a w n l a r v a e w e r e p r o d u c e d i n 1 9 8 4 ( L i ao ,1 9 8 5 ; C h i a n g a n d L i a o , 1 9 8 5 ) .

P U M P I N G , W A T E R D I S T R I B U T I O N A N D D R A I N A G ET h e a c c e s s o r i e s o f p r a w n p o n d s s u c h a s w a t e r p u m p i n g a n d i n l e t a n do u t le t s y s t em s a r e a s i m p o r t a n t a s p o n d c o n s t r u c t i o n .


6/15

2 2 4 l-Chiu Liao

i

i l -= ! I I,, - - - - - - ~ N~ . ~ ~ - -~"1 - ' - - .~- - - -L.1 : - i

I

( a )

A l g a e R e a r n g R e a r l n g t a n kc u l ~ u r e t a n ~ o f o f m y s i s a n dt a n k n a u p l i u s P l - 5a n d z o e a

I

( b )

R e a r i n g t a n k of p o a t - l a r v a

Fig . 2 . Schem at i c d i agram o f ha t che r i e s . (a ) Ha tche ry wi th roo fed t anks; (b)improved ha t chery ' w i th ou tdoor t anks covered wi th PVC shee t ; ( c ) a l adder s ty l eha t ch e~ ' an d nur se ry tak ing advan tage o f g roun d s lope and wa te r l eve ls .


7/15

General introduction to the prawn pond Ostern in Taiwan 2 2 5T h e r e a r e fo u r m a j o r m e t h o d s f o r w a t e r s u p p l y u s e d in T a i w a n

t o d a y . ( 1 ) T h e u t i l i z a t i o n o f h i g h a n d l o w t i d e s , s u p p l e m e n t e d w i t hp u m p i n g , u su a l ly s u p p l i e s w a t e r t o p o n d s l o c a t e d n e a r r iv e r s o r e s tu a -r ie s. (2 ) S h o w n i n F i g . 3( a) , p i p e s a r e e x t e n d e d i n t o c o a s t a l w a t e r f o rd i r e c t p u m p i n g o f se a w a t er . N o f il tr a ti o n is u s e d t o p r e v e n t u n w a n t e do r g a n i s m s f r o m e n t e r i n g t h e p o n d . ( 3 ) S h o w n i n F i g . 3 ( b ) , p i p e s a r eb u r i e d i n t h e s a n d o n t h e b e a c h a n d s e a w a t e r is t h u s n a t u r a ll y f il te r e dw h e n i t is p u m p e d . S o m e t i m e s a s ea w a t e r w e l l is d u g in t h e s a n d a n dt h e n t h e n a t u r a l l y f i l t e r e d s e a w a t e r i n t h e w e l l is p u m p e d t o t h e p o n d s .(4 ) W h e n u n d e r g r o u n d s e a w a t e r is p u m p e d , a w a t e r s p il li ng l a d d e r isu s e d t o e x p o s e t h e l e s s o x y g e n a t e d w a t e r t o a i r b e f o r e i t i s u s e d f o rprawn cu l tu re (F ig . 3 (c) ) .

l ! I_ ......... 1 I

(a !

(bi clF i g . 3 . T h r e e s y s t e m s f o r p u m p i n g s e a w a t e r . ( a) d i r e c t p u m p i n g f r o m c o a st a l w a t e r :( b) p u m p i n g f r o m t h e c o a s t a l s a n d l a y e rs ; ( c) p u m p i n g f r o m u n d e r g r o u n d a n d e x p o s -

i n g t h e w a t e r t o a i r b y a l a d d e r r a c e w a y .


8/15

2 2 6 1 - C h i u L i a o

J l i < ~ ii _ , ,Z 5 - -

t : a l

; i

Iv

pH

Fi g . 4 . I l l u s t r a ti on o f va r i ous w a t e r -ga t e s fo r i n le t and ou t l e t.

T o u t il iz e t h e t i d a l d i f f e r e n c e f o r f il li n g a n d d r a i n i n g , o n e o f t h ew a t e r - g a t e s s h o w n i n F ig . 4 i s u s u a l l y u s e d . I n o r d e r t o i n c r e a s e t h ew a t e r f l o w i n g t h r o u g h t h e f il te r n e ts . t h e d e s i g n h a s b e e n i m p r o v e d t oi n c r e a s e t h e t o t a l f i l t e r s u r f a c e a r e a . T h e i n l e t a n d o u t l e t w a t e r - g a t e sa re p o s i t i o n e d a t l o c a t io n s f o r m o s t f u n c t i o n a l w a t e r s u p p l y a n d d r a in -a g e. W h e n w a t e r is s u p p l i e d b y p u m p i n g , a m o r e f l e xi b le a n d e f fe c ti v ew a t e r s y s t e m c a n b e u s e d . T a k i n g t h e c e n t r a l d r a i n a g e d e v i c e a s a ne x a m p l e , i n a d d i t i o n t o t h e c e n t r a l w a t e r - g a t e , t h e r e i s a s i d e g a t e a to n e c o r n e r f o r c o m p l e t e d r a i n a g e d u r i n g t h e f in a l h a r v e s t a s w el l a s f o rs l u d g e r e m o v a l .

A E R A T I O N D E V I C EF a r m e r s o f t e n u n d e r e s t i m a t e t h e d i f fe r e n c e a w e l l - d e s i g n e d a e r a t io nd e v i c e c a n m a k e i n i n c r e a s i n g t h e f i n a l p r o d u c t i o n . A c c o r d i n g t o t h e


9/15

Gen e r a l n t r o d u c t i o n t o th e p r awn p o n d ~ ,st er n n T a i wa n 2 2 7

a u t h o r 's e x p e r ie n c e , o n e c a n st o c k o n l y 3 0 0 0 0 - 5 0 0 0 0 p r a w n s h a -in a n o n - a e r a t e d p o n d , w h i l e 3 0 0 0 0 0 - 7 0 0 0 0 0 p r a w n s h a - ~ c a n b es t o c k e d in a m o d e m , w e l l d e s i g n e d a n d e f f i c ie n t ly a e r a te d p o n d . T h i sd i f f e r e n c e i s m o s t l y d u e t o t h e u s e o f a e r a t i o n e q u i p m e n t t o i n c r e a s ed i s s o l v e d o x y g e n i n t h e w a t e r .

S e v e r a l p r e v a i l i n g s t y le s o f a e r a t i o n a r e i l l u s t r a t e d in F i g . 5 . T h em o s t e c o n o m i c a n d a c c e p t a b le o n e i s t h e p a d d l e w h e e l w h i c h h a sg r e a tl y b e n e f i t e d p r a w n f a r m e r s . P e o p l e h a v e b e e n e x p l o r i n g w a y s t oi m p r o v e t he m e c h a n i s m i n t er m s o f m o r e d u r a b l e m a t e r ia l s a n d

. ,~ -Q ; . ~ , 2 :

: ! ] . . I

l a !

t b )

(d ~

%!'eli

" i ~ - ; z ~ ; .: : ; , -

, ~ . , . :v . . " r" : : . -

i c i ( f ' iF i g . 5 . V a r i o u s a e r a t i o n d e v i c e s . ( a ) A e r a t i o n w i t h a i r s t o n e ; ( b ) a i r l i f t ; ( c ) r o t a t i n ga e r a t i o n w i t h r e d u c t i o n m o t o r ; (d ) p a d d l e w h e e l ; (e ) p o n d b o t t o m p i p e s u p p l ie d w i t h

a ir : ( f ) w a t e r s u r f a c e p i p e w i t h t in y f o u n t a i n s .


10/15

2 2 8 l - C h i u L i a oefficiency. The placement of the paddle wheel is also being studied todiscover the best location for optimal pond aeration.

TWO FOREIGN SYSTEMS OF PRAWN PONDThe intensive culture pond system of kuruma prawn in Japan and thesuperintensive prawn culture pond system in Hawaii are introducedfor reference and comparison.Figure 6 illustrates a circular intensive culture pond (23 m indiameter and 2.5 m deep) for kuruma prawn in Japan. It was designedespecially for the kuruma prawn which has the habit of burying itselfin the bottom sand and whose growth and survival rates are closelyrelated to the condi tion of the bottom layer of sand. How to preventthe sand layer from fouling during daily use was the key concernduring pond design and construction. As shown in Fig. 6, a false sandbed is made with an empty, deeper bot tom to make use of the circlingwater current to efficiently expel wastes into the central drain pipe(Fig. 6 -- G). In addition, a continuously rotating spray inlet pipe (Fig.6 - - B) across and over the pond, and two bottom drain pipes (Fig.6 -- I) under the false sand bottom, are installed for better sand filtermaintenance and water exchange. Although such a facility can achievea unit production as high as 27-6 tonnes ha -1 (Kurata e t a l . , 1984;Shigueno, 1985), it would cost a large amount of money and labor to

8Ir ' ~ A

A : G a t e ~ a l v e a t s ~ x o y - ~ p e6 : $ ~ r a y - m P eC : C y l i n d r i c a l s c r e e nO: SandE : C o n c r e t e . b o r t o mF : O o i n ~ l v e

G : M a i n d r a i n ~ iO eN : G ale va lve o f dr a in p i l o t[ : B o l l o m o Y a i n pi0e

- - - - - I : P~QsIic l "~ucdle Io sul :~,octb e d

C

F ig . 6 . S i m p l e d i a g r a m o f s t r u c t u r e a n d w a t e r sy s t e m f o r c u l tu r in g k u r u m a p r a w nP ] a p o n i c u s ( a f t e r S h ig u en o , 1 9 7 5 ; K u ra ta e t a l . 1984).


11/15

G e n e r a l i n tr o d u c t io n t o t h e p r a w n p o n d s y s t e m i n T a iw a n 2 2 9C O N T A C T r I N F I . A T I O NH E A T / F A N 'E X C N ~ ' I G R ~ /~ \ / /-cmcut.AT~ON

, . F L . a T E O - . . . ~~ , , . ~ ' , ~ / / F , , .

Fig. 7 , Aq u a c e l l w i th wa lk w a y a n d ra c e w a y fo r c u l tu r in g y e l lo w- le g s h r imp P . cali-f o rn i ens i s ( a f te r M a h l e r et al., 1974).

c o n s t r u c t a n d m a i n t a i n t h e fa ls e sa n d b e d i n p r i m e c o n d i t i o n . T h e r e -f o r e t hi s s y s t e m is n o t r e c o m m e n d e d f o r a n y p r a w n o t h e r t h a n t h ek u r u m a p r a w n , w h o s e m a r k e t v a l u e c a n r e a c h t h e in c r e d i b ly h i g hp r ic e o f U S S 8 0 k g - L n Ja p a n .

F i g u r e 7 i l l u s t r a t e s a s u p e r i n t e n s i v e p i l o t c u l t u r e p o n d f o r p r a w nc u l t u r e ( M a h l e r e t a l . , 1 9 7 4 ) . I n o r d e r t o c u l t u r e b l u e s h r i m p a t a ne x t r e m e l y h i g h d e n s i t y , t h i s s y s t e m w a s a d o p t e d i n H a w a i i . T h i ss y s t e m c o n s i s ts o f t w o s e t s o f 1 0 m x 5 0 m r a c e w a y s i n a n a q u a c e l l.T h e w a t e r is a e r a t e d w i t h s p l a s h in g a n d a n 0 2 c o n t a c to r . T h i s s y s t e mc a n b e s t o c k e d a t a d e n s i t y o f o v e r 4 k g m - z a n d h a r v es ts o f 7 0 t o n n e sh a -~ c r o p -~ h a v e b e e n r e p o r t e d (J. R . C a r p e n t e r , N . C h w a n g ,p e r s o n a l c o m m u n i c a t i o n s ) . S u c h a s y s t e m g iv e s t h e h i g h e s t h a r v e s t o fa n y p e n a e i d p r a w n c u l t u r e s y s t e m k n o w n . I f t h e t e c h n o l o g y tr a n s fe r o ft hi s id e a l c u lt u r e p o n d s y s t e m i s d e s i r e d , o n e s h o u l d c o n s i d e r t h e c o s to f th i s a q u a c e l l t e c h n o l o g y , m a n a g e m e n t , a n d t h e f e a si b il it y if a p p l i e dt o o t h e r p e n a e i d s p e c i e s.

D I S C U S S I O NT h e h i s to r y o f in t e n s i v e p r a w n c u l t u re i n T a i w a n is sh o r t e r t h a n t h a t inJ a p a n , w h e r e t h e p i o n e e r i n g w o r k w a s d o n e ; h o w e v e r , a m o r e


12/15

2 3 0 l - C h i u L i a o

p r o g r e s si v e d e v e l o p m e n t h a s b e e n m a d e in T a i w a n . T h e a n n u a l p r o d u c -t i o n o f c u l t u r e d g r a s s p r a w n i n T a i w a n s l i g h t l y e x c e e d e d t h a t o fc u l tu r e d k u r u m a p r a w n i n J a p a n in 1 9 7 8 , b u t b e c a m e 1 2 . 5 ti m e s m o r ein 1 98 5 ( Table 1 ). I t i s be l i e ved t hat the d i f f erence w i l l be co m e evenla rg er i n th e f u tu r e . O t h e r e v i d e n c e o f t h e r a p id d e v e l o p m e n t o f gr a s sp r a w n c u lt u re i n T a i w a n i s ~ v e n in T a b l e 2 . A m o n g t h e fi ve m a j o rg r a s s p r a w n e x p o r t i n g s o u r c e s f r o m w h i c h J a p a n i m p o r t e d i n 1 9 8 1 ,T a i w a n w a s i n l a s t p l a c e w i t h o n l y 1 0 0 t o n n e s . B y 1 9 8 5 , T a i w a n h a db e c o m e t h e l a r g e s t e x p o r t i n g s o u r c e o f g r a s s p r a w n t o J a p a n w i t hm o r e t h a n 1 3 0 0 0 t o n n e s o r 4 2 % o f th e to t a l J a p a n e s e i m p o r t s o ff rozen grass prawn. I t i s l ike ly t hat Taiwan wi l l cont inue t o rank f i r s tf or a t l eas t t he next f ew years . I t shou ld be e spec ia l ly not ed t hat t heg r a s s p r a w n e x p o r t e d f r o m T a i w a n i s o b t a i n e d t o t a l l y f r o m p r a w nf a rm s i n s t e a d o f o c e a n h a r v e s t.

T h e c o n t i n u o u s p r o g r e s s o f p r a w n c u lt u r e in t h e f u tu r e w il l d e p e n dup on imp rov ing cu l t ure t ech no log ie s . Th i s , in t urn , ,,','ill de pe nd on t hec o m b i n a t i o n o f e n ~ n e e r i n g , a r c h i t e c t u r e , a n d h a r d w a r e d e s i g n a n d

T A B L E 1C o m p a r i s o n o f A n n u a l P r o d u c t i o n o f G r a s s P r a w n I : m o n o d o n i n T a i w a n a n d

K u r u m a P r a w n l ~ . j a p o n i c u s i n J a p a n f r o m 1 9 7 4 t o 1 9 8 51 9 7 4 1 9 7 5 1 9 7 6 1 97 7 1 9 7 8 1 9 7 9 1 98 0 1 9 8 1 1 9,5 '2 19,5'3 1 98 4 196'5I ~.]aponicus9 11 9 3 6 1 0 4 2 I 1 24 1 1 84 1 4 8 0 1 5 4 6 1 6 6 6 2 0 0 0 1 9 4 9 2 0 3 7 2 4 0 0I'. mot todot t1 40 1 50 2 7 0 1 1 00 1 5 5 6 4 1 2 3 5 0 0 0 6 0 0 0 8 0 0 0 1 5 0 0 0 1 8 0 0 0 3 0 0 0 0

Unit: tonnes.T A B L E 2

E x p o r t o f F r o z e n G r a s s P r a w n P . m o n o d o n t o th e J a p a n e s e M a r k e t f r o m F i v eP r i n c i p a l P r a w n E x p o r t i n g S o u r c e s f r o m 1 9 8 1 t o 1 9 8 5

Year B a n g h t d e s h I n d i a I n d o n e s i a T a i w a n P h i l i p p i n e s T o t a l1 9 8 1 2 5 0 0 2 5 0 0 8 0 0 1 0 0 I 0 0 0 6 9 0 01 9 8 2 3 0 0 0 3 0 0 0 1 0 0 0 1 3 0 0 I 5 0 0 9 8 0 01 9 8 3 3 0 0 0 3 0 0 0 1 5 0 0 5 0 0 0 2 5 0 0 1 5 0 0 01 9 8 4 3 5 0 0 4 2 0 0 3 9 0 0 7 7 0 0 3 5 0 0 2 2 8 0 01 98 5 4 9 0 0 4 5 0 0 4 4 0 0 1 3 0 0 0 4 0 0 0 3 0 8 0 0

U n i t : t o n n e s .


13/15

General introduction to the prawn pond system in ~liwatl 231

construction. At present, the technology most lacking in Taiwan isaquaculture engineering. The majority of prawn farms in Taiwan arefamily-run. Farmers seldom ask professionals for help in planning anddesigning the culture ponds; rather they construct their farms accord-ing to personal preference, limited know-how, and the experience ofother farms. Lacking a blueprint for coordinated design of the prawnculture area, one frequently finds an array of odd shapes and sizes ofponds, with water pipes added every which way, often as an after-thought. The scene not only detracts from the eye, but also frompotential profits. This haphazard construction already causes drainageproblems which may result in contamination and disease. In addition,prawn culture areas for grass prawn, lacking aquaculture engineering,are already seriously taxing the underground water supply, which inturn causes land depressions and salt water incursion. A better overallplan with stronger management must be devised. Recirculatingsystems also need to be designed to reduce these problems.Some 17 years ago, pioneers in grass prawn culture had to decideon an optimum size of hatchery pond. This was the initial engineeringstep in this field. At that time the large 100 tonne hatchery tank used forthe community culture system of kuruma prawn in Japan was the onlyreference. To use such a large hatchery pond, one must acquire a goodnumber of spawners or millions of larvae at the same time. However,large numbers of spawners of grass prawn are very difficult to obtain.Thus, it was assumed that large hatchery' tanks would be neitherpractical nor economical. After lengthy consideration, the small sizedhatchery pond was adopted by the author and also by privatehatcheries following the author's suggestion. Finally a separate culturesystem especially designed for grass prawn hatcheries was established.If the large sized pond similar to that used for kuruma prawn hadoriginally been adopted, no doubt many of the inconveniences, head-aches and problems currently being experienced by other countrieswould have been encountered here as well (Liao, 1981). This suggeststhat aquaculture engineering has a great and lasting effect on prawnculture as a whole. It is hoped that aquaculture engineers andspecialists will carry' out meaningful research to further benefit theaquaculture industry'.

In summary, aquaculture engineering should contribute greatly tothe future development of the prawn culture industry, Greater auto-mation is needed and must come from the use of modern day


14/15

232 l-Chiu Liaotechnologies. The current mosaic of disorder and waste at the pondsite will gradually give way as economic factors and proper manage-ment are taken into further consideration. When the principles andpractices o f sound engineering know-how are applied, together with aknowledge of biology, ecology and economics, the prawn industrycannot help but become stronger.

ACKNOWLEDGEMENTSThe author is indebted to Nai-Hsien Chao, Pamela Wang, Chin-ChuTseng, Li-Lan Ling, Yi-Ping Chen, and Yuan Wang who made helpfulsuggestions and contributions to complete this manuscript. Theauthor also thanks Mr Y. H. Chou, Chief Engineer of Cheng-PingArchitect and Associates, for his enthusiastic assistance.Finally, the author would like to thank the China Committee forScientific and Scholarly Communication with the United States, theAcademia Sinica, ROC; and the Board of Science and Technology forInternational Development, Office of International Affairs, NationalResearch Council, USA. They organized the workshop and providedthe participants with the opportunity to discuss common interests inaquaculture engineering and simulation.

REFERENCESChiang, R & Liao, I. C. (1985). The practice of grass prawn (Penaeusm o n o d o n ) culture in Taiwan. Presented at the 1 6 th An n u a l Mee t in g o f th e

World M aricu lture Society, Orlando, Florida, USA, 13-17 January, 1985.Huang, T. L. (1969). Prawn culture. Bull. Fish. Assoc. Taiwan, 1, 54-60.Kurata, H., Shigueno, K. & Yatsuyanagi, K. (1984). Kuruma shrimp culture inJapan. N O AA Tech nica l Rep o r t HM FS , 1 6 , 9 -1 5 .Liao, I.C. (1981). Status and problems of grass prawn culture in Taiwan.Presented at R O C - J A P A N S y m p o s i u m o n M a r i c u l t u r e , Taipei, Taiwan,ROC, 13-24 December, 1981.Liao, I. C. (1985). A brief review on the larval rearing techniques of penaeidprawns. In: Proceedings o f the First Intern ation al Conference on the Cu ltureo f Pen a e id Pra wn s /S h r imp s , eds Y. Taki, J. H. Primavera and J. A.Llobrera, Aquaculture Dept. SEAFDEC, Iloilo, The Philippines, pp.65-78.


15/15

Ge neral introduction to the praw n p on d s3'stern in Tai~'an 233Liao , I. C . & C h ao , N . H . ( 19 8 3 ) . D ev e lo p m en t o f p r awn c u l tu r e an d i tsr e l a t ed s tu d ie s in Ta iwan . P r e sen ted a t Firs t In terna t iona l B ienn ia l Con-

f e r en ce o n Wa r m Wa ter A q u a c u ln l r e - - C r u s ta cea , B r i g h am Y o u n g U n i v e r -s ity , Hawa i i Ca m p u s , La ie , Hawa i i , USA . 9 -1 1 Feb ru a ry . 1 9 8 3 .L iao . I . C . & Hu an g , T . L . ( 1 9 7 3 ) . Ex p e r im en t s o n th e p ro p ag a t io n an dcu l tu re o f p rawns in Ta iwan . In : C o a s ta l A q u a cu l t u r e i n t h e In d o -P a c i f i cReg ion , ed . T . V. R. Pil lay , F ish ing News, L on do n , pp . 2 38 -35 4 .Liao . I . C. , Huang , T . L . & Katsu tan i . K. (1969) . Summary of p re l iminaurepor t on a r t i f ic ia l p ropagat ion o f P en a eu s r n o n o d o n Fabricius. JC R R F i s h .Ser., 8 , 6 7 - 7 1 .Liu , M. S . & M anc ebo , V. J . (1983) . P ond cu l tu re o f Penae,~s rnonodon in thePh i l ip p in es : su rv iv a l , g ro wth an d y ie ld u s in g co m m erc ia l ly fo rm u la t edfeed . J. W orld M aricul . Soc. , 14, 7 5 - ' 8 5 .Mah le r , L . E ., Gro h , J . E . & H o d g es , C . N . ( 1 9 74 ) . Co n t ro l l ed -e n v i ro n m en taq u acu l tu r e . P ro c. Wo r ld Ma r i cu L S o c. , 5 , 3 7 9 -8 4 .Shigue no , K. (1975) . S h r imp C u l tu r e i n Ja p a n , Ass o c ia t io n fo r I n t e rn a t io n a lTech n ica l P ro m o t io n , To k y o , Jap an , 1 53 p p .Sh ig u en o , K . ( 1 9 8 5 ). I n t en s iv e cu l tu r e an d f eed d ev e lo p m en t in P en a eu sja p o n i cu s . In : P r o ceed in g s o f t h e F i r s t In t e r n a t i o n a l C o t (e r e , w e o n t h eCul ture o f Penaeid Prawns /Shr i rnps , eds Y. Taki , J . H. Pr imavera and J. A.L lo b re r a, Aq u acu l tu r e Dep t , S E A F D E C . I lo ilo , Th e Ph i l ip p in es , p p .1 1 5 - 2 2 .

liao 1986 aquacultural-engineering

Documents