Madenjian 1987 Aquacultural-Engineering

7/28/2019 Madenjian 1987 Aquacultural-Engineering

1/18

Aquacultural Engineering 6 (1987) 191-208

P r e d ic t i n g N i g h t T i m e D i ss o lv e d O x y g e n L o s s i n P r a w nP o n d s o f H a w a ii: P a r t I . E v a l u a t io n o f T r a d it io n a lM e t h o d sC h a r l e s R M a d e n j i a n , G a r y L . R o g e r s a n d A r l o W . F a s t

Haw aii Institute of M arine Biology,Universityof Haw aii, PO Box 1346, Hono lulu,Haw aii 96744, US A

A B S T R A C TSeveral candidates (secchi d isc depth , in vivo f luorescence , ch lorophy l l aconcen t ra tion , turb id imeter m easureme nt , l igh t absorbance) fo r an ind i -cator of wa ter coh~mn respiration in pr aw n ( M a c r ob r a c h i um r o s enbe r g ii )po nd s o f H aw af f were evaluated. The % variat ion in the water co lum nrespiration rate expla ined by the indicator and water temp erature d id notexceed 6 0 % f o r a n y o f th e p o t en t ia l in dicato rs . P o n d D O a n d wa t e r t em -p er a tu r e were m o n i t o r ed o ver n i g ht a t p r a w n p o n d s i n Ka h u k u (O ah u).Addi t iona l l y , wa ter co lum n respirat ion rate in the po nd s was es t imated bythe dark bo t t l e method . On average , w a ter co lu m n (or p lank ton) respira-t ion com pr i sed 42% o f the who le po n d respi ra tion . Sed ime nt respi ra tionaccoun ted fo r 50 '2% o f the who le p on d respirat ion . The log- l inear (orexponen t ia l ) ex t rapo la t ion t echn ique y ie lded subs tan t ia ll y more accura tee s ti m a te s o f d a wn D O i n th e A m o r i e n t p o n d s t h a n t h e l in ea r ex tr a p o la -tion routine.

I N T R O D U C T I O ND i s s o l v e d o x y g e n c o n c e n t r a t i o n ( D O ) i s o n e o f t h e m o s t i m p o r t a n tf a c to r s a f f e c ti n g m o s t a q u a c u l t u r e s p e c ie s . W h e n d i s s o l v e d o x y g e n l e v el si n a q u a c u l t u r e p o n d s b e c o m e lo w , t h e c u l tu r e d o r g a n i s m s m a y b e c o m es t r e s se d o r e v e n d i e. D u r i n g t h e d i u r n a l c y c le , D O is ty p i c al ly lo w e s t a td a w n . A f t e r s u n r i s e . D O i n c r e a s e s d u e t o p h o t o s y n t h e s i s ; b u t a t n i g h t,b i o t ic r e s p i r a t i o n a n d c h e m i c a l o x i d a t i o n s r e s u lt i n a n e t l o ss o f o x y g e nw h i c h c a n r e a c h c r it ic a ll y lo w c o n c e n t r a t i o n s .T h e f a r m e r c a n a d d o x y g e n to t h e p o n d b y s e v e ra l m e t h o d s i n c lu d i ng :( 1 ) f l u sh i n g w a t e r i n to t h e p o n d , w h e r e b y w a t e r is d r a i n e d f r o m t h e p o n da s w a t e r w i t h a h i g h e r D O is a d d e d ; a n d ( 2) a e r a t i o n o f t h e p o n d w a t e r

191,4quacultural Engineerin~ 014 4-860 9/87/S0 3.50-- Else vier Appl ied Sc iencePublishers k td , Eng land. 1 987 . Printed in G reat Britain


2/18

192 C. P. Madenfian, G. L. Rogers, A. W. Fastb y s o m e m e c h a n i c a l d e v i c e . B o t h m e t h o d s a r e e n e r g y i n t e n s i v e a n ds h o u l d n o t b e u s e d u n l e s s n e e d e d .I f e a r l y m o r n i n g D O i n t h e p o n d w a s p r e d i c ta b l e b a s e d o n a fe wm e a s u r e m e n t s m a d e a t s u n s e t o r a f e w h o u r s t h e r e a f t e r , t h e f a r m e rw o u l d t h e n b e a b l e to d e t e r m i n e w h e t h e r e m e r g e n c y a e r a t i o n w a s n e c e s -s a r y . S u c h p r e d i c t i o n s w o u l d a l l o w t h e f a r m e r t o a e r a t e o n l y w h e nn e e d e d a n d t h u s r e d u c e o p e r a ti n g e x p e ns e s w h ile a t th e s a m e ti m each i ev i ng i n t ens i ve leve l s o f c rop p rod uc t i on .T he i n t en t o f t h is s tudy w as t o desc r i be m a t hem a t i ca l l y t he n i gh t t im ed i s s o lv e d o x y g e n d y n a m i c s o f p r a w n ( M a c r o b r a c h i u m r o s e n b e r g i i ) p o n d si n H a w a i i ba s ed on a se t o f a f ew va r iab l e s t ha t cou l d be ea s i l y m easu re db y t h e p r a w n f a r m e r . A c c o m p l i s h i n g t h i s o b j e c t i v e w o u l d f u r n i s h t h ep r a w n f a r m e r w i t h a u s ef u l p r e d u c t o r o f e a r l y m o r n i n g D O i n t h e p o n d s .T h e n i g h t t i m e d y n a m i c s o f d i s s o l v e d o x y g e n i n c h a n n e l c a t f i s h( I ct a l u r u s p u n c t a t u s ) p o n d s i n A u b u r n , A l a b a m a h a v e b e e n s u c ce s s fu l lym o d e l e d b y B o y d e t a l . ( 1 9 7 8 ) . T h e i r m o d e l a c c o u n t s f o r c h a n g e s i noxygen concen t ra t i on due t o d i f fu s i on , oxygen l o s s f rom ca t f i sh r e sp i r a -t i o n , l o s s f r o m s e d i m e n t r e s p i r a t i o n , a n d o x y g e n c o n s u m e d t h r o u g hp l a n k t o n r e s p i r a t i o n . W e s h a l l u s e t h e t e r m p l a n k t o n r e s p r i a t i o n i n t e r -c h a n g e a b l y w i t h w a t e r c o l u m n r e s p i r a t i o n . O f t h e f o u r a f o r e m e n t i o n e dc o m p o n e n t s , p l a n k t o n r e s p i r a t i o n w a s th e g r e a te s t fa c t o r o f D O d e c l in ei n t h e A u b u r n c a t fi s h p o n d s ( R o m a i r e , 1 9 7 9 ). R o m a i r e a t t r ib u t e d t h esuccess o f t he m ode l t o t he r e l i ab le p red i c t i on o f p l an k t on r e sp i r a t ion .R o m a i r e w a s a b l e t o p r e d i c t p l a n k t o n r e s p i r a t i o n a s a f u n c t i o n o fw a t e r t em per a t u re and secch i d i sc v i s ib i li ty i n an e qua t i on o f the fo l low -i ng fo rm :

r=co+cISDD+c2SDD2+c3T+c4T2+csSDDT (1)w h e r e r = p l a n k t o n r e s p ir a ti o n r a te ( m g O : l it er -~ h -~ ) , S D D = s e c c h idisc d ep th (cm), T-- w ate r tem pe ra tu re (C), c . , c~, c 2, c 3, c4, c5 = reg res-s i on coe f f i c i en t s . The f i t o f t he equa t i on t o t he A uburn pond da t a w asg o o d ( R 2 = 0.82).

I n H a w a i i, L o s o r d o ( 1 9 8 0 ) e x p l a i n e d 7 9 % o f t h e v a r i a t io n in p l a n k t o nre sp i r a t i on r a t e o f f r e shw a t e r p raw n p ond s us i ng a r eg re s s i on ana l ys i ss i m i l a r t o t ha t o f Ro m ai re ' s , bu t u sed r e l a ti ve l y f ew obse rva t i ons .L o s o r d o u s e d o n l y t h r e e o b s e r v a t i o n s a t 2 8 C , a n d o n l y t h r e e o b s e r v a -t i o n s a t 3 2 C . T h e o n l y o t h e r i n c u b a t i o n t e m p e r a t u r e e m p l o y e d i n t h ee x p e r i m e n t w a s 2 4 C , a t w h i c h 2 0 o b s e r v a t i o n s w e r e r e c o r d e d .S e v e r a l r e s e a r c h e r s h a v e c o n c l u d e d t h a t p l a n k t o n r e s p i r a t i o n i su s u a l l y t h e m a j o r c o n s u m e r o f o x y g e n a t n i g h t i n f r e s h w a t e r p r a w np o n d s o f H a w a i i ( L o s o r d o , 1 9 8 0 ; C o s t a - P i e r c e et al . , 1984 ; Cos t a -


3/18

Predicting night t ime D O loss: Part I 193Pierce , pers . comm. , Oceanography Dept . , Univ . Hawai i , Honolulu , HI) .Losordo found t ha t t he wa t e r co lumn r e sp i r a t i on ( a s measured i n t heda rk bo t tl e ) accoun t ed fo r, on ave rage, abou t 60% of the ove rn igh t DOdecl ine observed in the pond. Based on h i s s imula t ion model , Romai re(1979) es t imated tha t , on average , about 80% of the overnight DOdecrea se in the Au bu rn po nd co uld be a tt r ibuted to the p lank ton respi ra-t ion rate .A n average sediment respi ra tion ra te of 60 mg 02 m -2 h -~ w asrepor t ed by Cos t a -P i e r ce e t a l . (1984) fo r Hawa i i an p rawn ponds andwas the average ra te sugges ted for use in model ing ef for t s (Cos ta-Pierce ,pers . comm .). How ever , Fas t e t a l . (1983) and G arza (unpub li shed m anu-scr ip t , Hawai i Ins t i tu te of Mar ine Biology, Univ . Hawai i , Kaneohe , HI)r epor t ed mean sed imen t r e sp i r a t i on r a t e s i n Hawai i an p rawn ponds o f221 and 281 m g 02 m -2 h -~ , respec tive ly . Th e d i f fe rence be twee n thesees t imates and those of Cos ta-Pierce e t a l . (1984) may be a t t r ibuted todifferences in techniqu e or locat ion.In an ent i re ly d i f fe rent approach to predic t ing dawn DO in theAu burn ca tf ish ponds , Bo yd e t a l . (1978) conc luded t ha t the D O dec li nedur ing the n ight was essent ia l ly l inear . By measur ing DO a t dusk andthen aga in 2 -3 h a f t e r dusk , the morn ing D O pred i c ti on cou ld be ex t r a -pola ted f rom the l ine connect ing the two evening DO observa t ionsplot ted against t im e (Fig. 1 ). Th is ex trapolat ion techniqu e pe rfo rm ed aswel l as Romai re ' s s imula t ion model descr ibed above for Alabama f i shponds .

108 -

t ' NO 6 -(3)E" " " * 4 -Ot ' l 2

% `%`

% `% `

% .% .

% .

PREDICTED ~ DAWN DO0 F1800 2400 0600

H O U RFig . 1 . I l l u s t ra t i on o f t he l i nea r ex t r ap o l a t i o n t e chn iqu e fo r p r ed i c t i ng pon d D O a td a w n .


4/18

194 C P. Ma den] ian , G. L . Rogers , A . W. Fas tM E T H O D S

P l a n k t o n r e s p ir a t io n a s a f u n c t i o n o f s e c c h i d i s c d e p t hT o d e t e r m i n e t h e r e l a t io n s h i p b e t w e e n p l a n k t o n r e s p i ra t i o n , t e m p e r a -tu re , a nd secch i." d i sc d ep th , t he fo l lowing exp e r im en t was con duc ted .T h r e e p r a w n p o n d s ( p o n d s A F 1 , A F 2 , a n d A F 3 ) f r o m a r e la ti v el y c a lm( s h e l t e r e d f r o m w i n d ) s i t e ( A q u a t i c F a r m s L t d , K a n e o h e ) a n d t h r e ep r a w n p o n d s ( p o n d s A 3 6 , D 1 7 , a n d D 1 8 ) f r o m a w i n d y s ite (A m o r i e n tA q u a f a r m I nc ., K a h u k u ) o n O a h u w e r e s a m p l e d f r o m A p r i l t o A u g u s t1 9 8 4 . D u r i n g e a c h s a m p l i n g t ri p, w a t e r w a s c o l l e c t e d f r o m e a c h o f t h et h r e e p o n d s a t th e s i te a n d s e c c h i d i sc d e p t h s w e r e r e c o r d e d . T h i r t y - o n et ri p s w e r e u n d e r t a k e n : 1 5 to A q u a t i c F a r m s a n d 1 6 to A m o r i e n t . W a t e rs a m p l e s w e r e t r a n s p o r t e d t o t h e U n i v e r s i ty o f H a w a i i a t M a n o a f o r i n c u -b a t i o n . P o n d w a t e r w a s c o l l e c t e d at a d e p t h o f 1 0 c m .F o r e a c h p o n d s a m p l e d , s e p a r a te i n c u b a t i o n s w e r e c o n d u c t e d a t th r e ed i f f e ren t t em pera tu re s (21 , 26 , and 32C). P r io r to m easu r ing r e sp i r a t i onra t e s , t he wa te r was mixed by bubb l ing a i r i n to i t . Th i s a l l owed thes a m p l e t o r e a c h a w a t e r t e m p e r a t u r e c l o s e t o t h e d e s i r e d i n c u b a t i o nt e m p e r a t u r e a n d t o b r i n g t h e w a t e r c l o s e to t h e d i s s o l v e d o x y g e n s a tu r a -t i o n p o i n t b e f o r e t h e i n c u b a t i o n b e g a n . A f t e r a p p r o x i m a t e l y 1 h i n t h eb a t h , t h e s a m p l e s w e r e p o u r e d i n t o 3 0 0 - m l B O D b o t t le s ( tw o r e p li c a te sf o r e a c h o f th e t h r e e t e m p e r a t u r e l ev e ls ) a n d i n c u b a t e d i n t h e d a r k f o r4 - 7 h . R e s p i r a t i o n r a t e s w e r e c a l c u l a t e d b y m e a s u r i n g o x y g e n l e v e l sb e f o r e a n d a f t e r i n c u b a t i o n f o r a k n o w n p e r i o d o f ti m e . D O w a smeasured us ing a YSI mode l 54 oxygen me te r (Ye l low Spr ings Ins t ru -m e n t C o m p a n y I n c ., Y e l lo w S pr in g s , O h i o ) w i th a B O D p r o b e e q u i p p e dwi th a s t ir r e r. D a ta were ana lyz ed us ing the S t a t i st ica l An a lys i s Sys tem(SAS) package (1982) .

R e g r e s s i o n s w e r e p e r f o r m e d o n t h e r a w d a t a ( w i t h o u t a v e r a g in g o fr ep l i ca t e obse rva t ions ) and on ave raged da t a . S t a t i s t i c i ans may a rguetha t by ave rag ing , t he ana lys t e l imina t e s the e r ro r con t r ibu ted by r ep l i ca -t i on and tha t t h is e r ro r shou ld be in c lud ed in the r eg res s ion ana lyses, bu tw e a v e r a g e d ( a v er a g e d a m o n g r e p l i c a t e d o b s e r v a t i o n s ) i n o r d e r t o c o m -pa re o u r r e su lt s w i th Rom ai re ' s r e su lt s .A d d i t io n a l l y , f r o m e a c h o f t h e p o n d s s a m p l e d f r o m A p r i l t o A u g u s t1 9 8 4 , tw o r e p l i c a te v o l u m e s o f p o n d w a t e r ( 5 0 o r 1 0 0 m l v o l u m e s ) w e r ef i lt e r ed th ro ugh a G F/C W ha tm an g l a s s fibe r f i lt e r (u sing a l ow-pres su rev a c u u m ) t o d e t e r m i n e t h e c h l o r o p h y l l a c o n c e n t r a t i o n in t h e p o n d w a te r.T w o m l o f s a t u r a t e d M g C O 3 s o l u t i o n w e r e a d d e d t o t h e w a t e r a s i t w a sf i l t e r ed . F i l t e r s were s to red d ry (wi th des i ccan t ) and then were g round(using t is sue g r inde r ) and d i s so lved in 90 % ace to ne so lu t ion (by vo lum e


5/18

Pr e d i c t in g n i g h t t i me D O l os s: Pa r t 1 195i n w a t e r ) . Sam pl es w ere a l l ow ed t o s t eep fo r a t l ea s t 24 h and t hena b s o r b a n c e o f t h e c h lo r o p h y l l e x t ra c t w a s r ea d o n a B e c k m a n D U - 7s p e c t r o p h o to m e t e r . T h e p r o c e d u r e o u t li n e d b y J e ff r ey a n d H u m p h r e y( 1 9 7 5 ) w a s u s e d t o e s t i m a t e c h l o r o p h y l l a f r o m t h e e x t r a c t a b s o r b a n c edata .O ther ind ica tors o f p lankton respira t ion ra teI n a n e x p e r i m e n t s i m i l a r t o t h e o n e d e s c r i b e d a b o v e , o t h e r i n d i c a t o r s ,i n c l u d i n g in vivo f l u o r e s c e n c e a n d t u r b i d i ty m e a s u r e d w i t h a H a c h t u r b i-d i m e t e r ( H a c h C o m p a n y , L o v e l a n d , C o l o r a d o ) , w e r e t e s t e d . W a t e rs a m p l e s w e r e c o l l e c t e d a t a d e p t h o f 1 0 c m f r o m e a c h p o n d s a m p l e d ;and t w o rep l i ca t e a l i quo t s (be t w een 3 and 5 m l ) w ere p i pe t t ed f rom t hew a t e r s am pl i ng bo t t l e t o a cuve t t e , and in vivo f l u o r e s c e n c e w a s m e a -su red us i ng a f l uo r om et e r (T urne r m ode l 111 ). W at e r t u rb i d i t y w asm e a s u r e d u s i n g a H a c h t u r b i d i m e t e r. A d d i ti o n a l ly , a 5 - 6 m l a li q u o t o fp o n d w a t e r w a s p i p e t t e d i n t o a c u v e t t e a n d a b s o r b a n c e ( a t 6 6 5 n m ) o ft h e p o n d w a t e r w a s m e a s u r e d w i th a s p e c t r o p h o t o m e t e r . In vivo f luor-e s c e n c e a n d t u r b i d it y w e r e m e a s u r e d w i t h in 1 h o f s a m p l e c o l le c ti o n .T w e n t y - t w o t r ip s w e r e u n d e r t a k e n . D u r i n g e a c h s a m p l i n g tr ip , si x p o n d sw e r e s a m p l e d ; u s u a ll y t h r e e f ro m A m o r i e n t i n K a h u k u a n d t h r e e fr o mt h e fa r m p o n d s a t B r ig h a m Y o u n g U n i v e r s it y - H a w a i i C a m p u s ( B Y U ) inL a i e. H o w e v e r , d u r i n g a f ew t r ip s a ll s ix o f th e p o n d s s a m p l e d w e r e B Y Up o n d s . ( N o t e t h e B Y U s it e w a s a n i n t e r m e d i a t e s i te as fa r a s w i n d s p e e dw as conce rned ; i t w as pa r t i a l l y she l t e red f rom w i nd , bu t no t a s m uch a st h e A q u a t i c F a r m s s ite ). E a c h o f t h e se v e n p r a w n p o n d s a t t h e B Y U f a r mw e r e s a m p l e d a t le a s t o n c e f r o m F e b r u a r y t o A p r i l 1 9 8 5 a n d f o u r d i ff e r-e n t p o n d s ( A 3 1 , A 3 6 , D 1 7, a n d D 1 8) w e r e s a m p l e d a t A m o r i e n t . P l a n k -t on r e sp i r a t i on r a t e w as m easu red a s desc r i bed above . Fo r a pa r t i cu l a rt r i p , a l l w a t e r w as i ncuba t ed a t one o f t he t h ree t em pera t u re s (21 , 26 ,and 32C) .O v e r n ight D O m o ni t o r ing a t A m o r ie nt po ndsF r o m J u n e t o S e p t e m b e r 1 9 8 5 , 1 5 o v e r n i g h t m o n i t o r i n g t r ip s w e r et r a n s a c t e d a t A m o r i e n t f a r m i n K a h u k u . T w o p o n d s w e r e m o n i t o r e dd u r i n g e a c h t r i p . D O a n d w a t e r t e m p e r a t u r e w e r e m e a s u r e d a t h o u r l yi n t e rva l s f rom sunse t un t i l a f t e r sun r i se (un t i l D O s t a r t ed t o i nc rease ) a tt w o s i te s (w es t and eas t s ides o f pond) a t each pon d . S u r face and b o t t omt e m p e r a t u r e a n d D O w e r e m e a s u r e d a t e a c h s ite u s i n g a Y S I m o d e l 5 4oxygen m e t e r w i t h a f i e l d p robe w i t h s t i r r e r . Seven d i f f e ren t ponds w erem o n i to r e d ( A I 8 . A 19 , D 1 1 , D 1 2 , D 1 3 , D 1 7 , a n d D 1 8 ) .


6/18

196 C. P. M ade nfian, G. L. Rogers, A . W. FastA 2 - l it e r w a t e r s a m p l e w a s c o l l ec t e d f r o m e a c h p o n d m o n i t o r e d ; th es a m p l e w a s m i x e d w e ll , a l lo w e d t o d e - g a s f o r 1 0 m i n , a n d a 3 0 0 - m l B O Dd a r k b o t t l e ( l i n e d w i t h a l u m i n u m f o i l a n d t a p e d w i t h b l a c k e l e c t r i c a l

t ape ) was f i l led (a l lowing to ove r f low a t l e a s t on e vo lum e o f t he bo t t le )a n d f ix e d i m m e d i a t e l y w i t h 2 m l o f MgSO 4 so lu t ion an d 2 m l o f a lka li -i o d i d e - a z i d e s o l u ti o n . A n o t h e r d a r k b o t t l e w a s t h e n f i ll ed a n d a l lo w e d t oi n c u b a t e in t h e p o n d o v e r n i g h t b y a t t a c h m e n t to a w o o d e n s t a k e d ri v e ni n t o th e p o n d b o t t o m . A b o u t 1 h b e f o r e d a w n , t hi s b o t t l e w a s f ix e d a sd e s c r i b e d a b o v e . W i n k l e r t i t r a t i o n s w e r e p e r f o r m e d t o d e t e r m i n e D O( E n v i r o n m e n t a l P r o t e c t i o n A g e n c y , 1 9 8 3 ). T h e r e s p i r a ti o n r a te o f t h ew a t e r c o l u m n ( as d e t e r m i n e d f o r t h e d a r k b o t tl e ) w a s c o m p a r e d w i t h t h ew h o l e p o n d r e s p i r a t i o n , a s d e t e r m i n e d b y e s t i m a t i n g t h e r e s p i r a t i o nc o e f f ic i e n t ( se e M a d e n j i a n et aL, 1 9 8 7 ). T h e w h o l e p o n d r e s p i r a ti o n ra t ew a s a d j u s t e d f o r t h e t e m p e r a t u r e a t w h i c h t h e p o n d w a s 1 0 0 % D Os a t u r a t e d ( a d j u s t m e n t w a s b a s e d o n w h o l e p o n d r e s p i r a t i o n r a t e a s a ne x p o n e n t i a l f u n c t i o n o f w a t e r t e m p e r a t u r e ; w i th e x p o n e n t i a l c o n s t a n t , k ,equa l to 0 . 0542) .T h e r e s p i r a t i o n r a t e i n t h e d a r k b o t t l e s u s p e n d e d i n t h e p o n d w a sa d j u s te d f o r th e t e m p e r a t u r e a t w h i c h th e p o n d w a s 1 0 0 % D O s a tu r a te d .I t w a s a s s u m e d t h a t r e s p i r a t io n r a t e o f t h e p l a n k t o n w a s a n e x p o n e n t i a lf u n c t i o n o f t e m p e r a t u r e :r=ce kT (2)

wh ere r i s t he r e sp i r a t i on r a t e i n mg O : l i t e r - ~h - t, c and k a re cons t an t s ,and T i s wa te r t em pera tu re (C). k was e s t ima ted f rom the r e sp i r a t i one x p e r i m e n t s c o n d u c t e d i n th e l a b ( w h e r e sa m p l e s w e r e i n c u b a t e d a t c o n -s t an t t em pera tu re ) t o be 0 . 0542 . c was e s t ima ted by f ind ing the ave raget e m p e r a t u r e d u r i n g i n c u b a t i o n in t h e p o n d a n d b y c a l c u la t in g t h eave rage r e sp i r a t i on r a t e:kTe

c = - - ( 3 )Y

T h e a v e r a g e r e s p i r a ti o n r a t e w a s f o u n d s i m p l y b y d i v id i n g t h e d r o p i nD O b y t h e d u r a t i o n o f th e i n c u b a t i o n i n t h e p o n d :( in i ti al D O - f in a l D O )

( d u r a t i o n o f i n c u b a t io n )T he ave rage t em pera tu re w as ca l cu l a t ed by fi tt ing an exp onen t i a l func -t i o n t o t h e t e m p e r a t u r e d a t a :

T= ae h' (4 )


7/18

Pred ic t ing n igh t t ime D O loss : Par t 1 197w here T i s t em pera tu re ( C), a and b a re cons t an t s , and t i s t ime . By in t e -g r a ti n g o v e r t i m e a n d d i v i d in g b y t i m e s p a n o f i n c u b a t i o n , a v e r a g e t em -p e r a t u r e w a s f o u n d .

O v e r n i g h t w i n d s p e e d d a t a c o i n c i d i n g w i t h t h e s a m p l i n g tr ip s a tA m o r i e n t w e r e f u r n i s h e d b y t h e H a w a i i N a t u r a l E n e r g y I n s t it u te , U n i v .H a w a i i . W i n d s p e e d w a s m e a s u r e d o n c e e v e r y 6 m i n a t a h e i g h t o f 2 4 .4m ( K a h u k u t o w e r ) a b o v e t h e K a h u k u f ia t a p p r o x i m a t e l y 2 k m f r o m t h eA m o r i e n t p o n d s . A n a v e r a g e w i n d s p e e d f o r e a c h s a m p l i n g n i g h t w a sca l cu l a t ed .T h e l i n e a r e x t r a p o l a t i o n t e c h n i q u e w as a p p l ie d t o th e D O m o n i t o r i n gd a t a f r o m A m o r i e n t . A d d i t i o n a l ly , a n e x p o n e n t i a l ( o r l o g - li n ea r ) e x t ra -po la t ion t echn ique was ap p l i ed to t he sam e da t a a s fo llows : t he twoD O o b s e r v a t i o n s ( o n e a t d u s k a n d o n e s e v e r a l h o u r s l a t e r ) w e r e l o g -t r a n s f o r m e d , t h e l o g a r i th m i c d a w n D O w a s p r o j e c t e d f ro m t h e s tr a ig h tl in e c o n n e c t i n g th e l o g - t r a n s f o r m e d o b s e r v e d D O v a lu e s p l o t te d a g a i n s tt im e , a n d t h e a n t i l o g a r i th m o f t h e l o g a r it h m i c d a w n D O w a s f o u n d . T h ea n t i l o g a r it h m o f t h e l o g ( d aw n D O ) w a s t h e p r e d i c t e d D O f o r th i s l og -l i nea r ex t r apo la t ion t echn ique . Fo r t he l i nea r ex t r apo la t ion t echn ique , i fd a w n D O w a s e x t r a p o l a te d t o b e le ss th a n z e ro , th e d a w n D O p r e d i c t i o nwas se t equa l t o ze ro . Ex t r apo la t ions were p roduced based on : (1 )obse rva t ions f rom the ea s t s ide o f t he pon d on ly , (2 ) obse rv a t ions f romthe wes t s ide o f t he pond on ly , and (3 ) t he ave rage o f t he obse rva t ionsf rom the wes t and eas t s ides ( an ave rage fo r t he po nd ; w e wi ll de s igna t eth i s s e t a s t he pond se t ) . The su r f ace and bo t tom DO were ave raged fo reach o f the t h ree se t s o f da ta .

R E S U L T S

S e c c h i d i s c d e p t h a s a n i n d i c a t o r o f p l a n k t o n r e s p i r a t i o n r a teT he f it o f the r eg re s s ion equa t ions fo r bo th s it e s po o led a s we ll a s bo ths ite s s e p a r a te l y w e r e n o t a d e q u a t e f o r p r e d i c t i o n p u r p o s e s ( R : b e t w e e n0-48 a nd 0 . 54 ) (T ab le 1 ). Va r i a t i on in p l an k to n r e sp i r a t i on r a t e ap pea redto incre ase w i th increa s ing turb id i ty (F ig . 2) .F o r a g i ve n d a y o f s a m p l in g , p o n d D 1 7 a t A m o r i e n t a n d p o n d A F 3 a tAq ua t i c Fa rms usua l ly exh ib i t ed a h ighe r r e sp i r a t i on r a t e ye t le ss t u rb idwa te r t han the o the r two p ond s a t t he s i te , r e spect ive ly . T he same r eg res -s ion ana lys i s a s fo r al l s ix pond s p oo led w as pe r fo rm ed on da t a j u s t fo rt h es e tw o p o n d s . T h e f it f o r d a ta f r o m p o n d s D 1 7 a n d A F 3 o n l y w a sadeq ua te fo r p re d i c t i on (R : = 0 . 81) (Tab le 1 ). Th e r eg re s s ion equa t ionwas :


8/18

198 C. P. Ma denf ian , G . L. Rogers, A . W. FastT A B L E 1Fract ion of Var iation (R 2) of Plank ton R espi rat ion Rate Explained as a Fun ct ion of Sec-ch i Di sc Dep th and W ater Tem pera tu re i n Hawai i an Prawn Ponds (The func tion was a

l inear com binat ion of secchi d isc dep th and w ater tem perature, the quadrat ic terms o fbo th of these factors , and the in teract ion term betw een secchi d isc dep th and w ater tem -perature. Da ta were for Am orient and A quat ic Farms, Oah u, Apri l to August 1984)Po nds inc lude d in analys is R ~

R a w d a ta A v e r a g in g(w itho ut averaging) replicatesPonds f rom b o th s it es p oo ledAmo r i e n t p o n d sAquat i c Farms pond sP o n d s A F 3 an d D 1 7 o n l y

0"536 0.5390"~,80 0.4840"510 0.5140"811 0.813

0 . 4

n-" ~ 0 .3

0.2

U.Ior"0 . 0

o o o o

- - * * o 9o

o2~] oo

# o o

o

I I

0 20 40 6 0

litO

SECCHI DIS C DE PTH (cm)Fig. 2 . Respi rat ion rate of p lankton (as determ ined b y dark bot t le) versus secchi d iscdepth in Hawai ian prawn ponds for incubat ion temperature of 26C. Data for bothAm or ien t and Aquat i c Farms , Oah u , were poo led . Experimen t s w ere conducted f romApri l to August 1984.

r = - 0 - 0 1 - - 0 " 0 0 6 4 S D D + 0 " 0 0 0 1 6 9 S D D 2 + 0 -0 1 6 T + 0 . 0 0 0 0 8 1 2 T 2- 0 . 0 0 0 3 4 4 S D D x T

w h e r e r - - p l a n k t o n r e s p i r a t i o n r a te (m g 0 2 l it e r -1 h - 1 ) , S D D - - s e c c h id i sc d e p t h ( cm ) , T = w a t e r t e m p e r a t u r e (*C ).C h l o r o p h y l l a , a s d e t e r m i n e d b y ex t r a c t io n a n d m e a s u r i n g a b s o r b a n c e

o f t h e e x t r a c t i o n o n a s p e c t r o p h o t o m e t e r , w a s n o t a p r a c t ic a l i n d i c a t o r o f


9/18

Predic t ing n ight time D O loss: Par t / 199p l a n k t o n r e s p ir a ti o n , s in c e th e p r o c e d u r e w a s t o o t e d io u s a n d t im e c o n -s u m i n g . H o w e v e r , ju s t t o i n v e s t ig a t e t h e v a r i a t io n i n th e s a m e r e s p i r a t i o nd a t a t h a t w a s r e g r e s s e d o n t e m p e r a t u r e a n d s e c c h i d i s c d e p t h ( A p r i l t oA u g u s t 1 9 8 4 ) , r e s p i r a t io n r a t e w a s re g r e s s e d a s a f u n c t i o n o f c h l o r o p h y l la a n d t e m p e r a t u r e u s i n g e q n ( 1 ) b u t s u b s t it u ti n g c h l o r o p h y l l a f o r s e c c h id i sc d e p t h i n t h e e q u a t i o n . C h l o r o p h y l l a w a s n o t a s u it a b le i n d i c a t o r o fp l a n k t o n r e s p i r a t i o n r a te ; it e x p l a i n e d ju s t s l ig h t ly m o r e v a r i a t i o n i n t h er e s p i r a t i o n r a te t h a n s e c c h i d i s c d e p t h . T h e R 2 v a l u es r a n g e d b e t w e e n0 . 4 7 a n d 0 . 6 0 ( si te s p o o l e d a n d s it es s e p a r a t e ) ( T a b l e 2). V a r i a t i o n i nr e s p i r a t io n r a t e in c r e a s e d a s c h l o r o p h y l l a c o n c e n t r a t i o n i n c r e a se d .I n t e r e s t i n g l y , t h e r e g r e s s i o n m o d e l o f r e s p i r a t i o n o n c h l o r o p h y l l a a n dt e m p e r a t u r e b a s e d o n d a ta fo r p o n d s A F 3 a n d D 1 7 o n ly , e x p l a in e da b o u t 8 0 % o f th e v a r i a t io n i n t h e r e s p i r a ti o n r a t e d a t a. T h e r e su l ts f o rc h l o r o p h y l l a p a r a l l e l e d t h e r e s u l ts f o r s e c c h i d i s c d e p t h .

TABLE 2Fraction of Variation (R 2) of Plankton Re spira tion RateExplained as a Function of C hlorophyll a and WaterTempera-ture in Haw aiian Prawn Po nds (The function was a l inear com-bination of chlorophyll a and water temperature, the quadraticterms of both of these facto rs, and the interaction termbetween chlorophyll a and water temperature. Data w ere forAm orient and Aqu atic Farms, Oahu , April to August 198 4)

Po nd s inc lude d in analysi s R 2Ponds from both sites pooledAm orient pondsAqu atic Farms pondsPonds AF3 and D17 only

0"6000"4730"5300"804

O t h e r i n d i ca t o r s o f p l a n k t o n r e s p i r a ti o n r a teb z v i v o f l u o r e s c e n c e o f a w a t e r s a m p l e i s e a si ly m e a s u r e d ; u n f o r t u n a t e l yf l u o r e s c e n c e w a s a ls o a n i n a d e q u a t e p r e d i c t o r o f p l a n k t o n r e s p i r a ti o nr at e, a s s h o w n b y d a ta f o r A m o r i e n t a n d B Y U f ar m s , F e b ru a r y t o A p r i l1 9 8 5 ( T ab le 3 ). F l u o r e s c e n c e a n d t e m p e r a t u r e a c c o u n t e d f o r le ss t h a n6 0 % o f t h e v a r i a ti o n i n t h e r e s p i r a ti o n r a t e d a ta . T h e t u r b i d i m e t e rm e a s u r e m e n t a s w e l l a s th e s p e c t r o p h o t o m e t e r r e a d i n g (a t 6 6 5 n m ) w e r ei n a c c u r a t e i n d i c e s o f w a t e r c o l u m n r e s p i r a t i o n r a te i n t h is d a t a s e t( F e b r u a r y t o A p r i l 1 9 8 5 ) ( T a b le 3 ). T h u s , n o n e o f th e p o t e n t i a ll y u s e fu lc a n d i d a t e s f o r a n i n d i c a t o r o f p l a n k t o n r e s p i r a t i o n r a t e t e s t e d i n t h i ss t u d y w e r e h i g h l y re l ia b l e .


10/18

2 0 0 C P. Maden]ian, G. L. Rogers, A . W. FastT A B L E 3Fr ac t i on o f V a r i a t ion ( R 2) o f P l ank t on Resp i r a t i on R a t e E xp l a i ned a s a Func t i on o f anI n d i c a t o r a n d W a t e r T e m p e r a t u r e i n H a w a i ia n P r a w n P o n d s ( T h e f u n c t i o n w a s a li n e ar

c o m b i n a t i o n o f t h e i n d i c a t o r a n d w a t e r t e m p e r a t u r e , th e q u a d r a t ic t e r m s o f b o t h o f th e s ef ac t o r s , and t he i n t e r ac t i on t e r m be t w een t he i nd i ca t o r and w a t e r t em pe r a t u r e . I nd i -ca t o r s i nc l uded in vivo f l uo r e scence , t u r b i d i ty (a s m easu r ed b y H ach k i t m e t e r ) , anda b s o r b a n c e ( a t 6 6 5 n m ) . D a t a w e r e f o r A m o r i e n t a n d B Y U f a r m . O a h u , F e b r u a r y t oA p r i l 1 9 8 5 )Po nds inc luded in analys is R 2

In v ivo Turb i d i t y Absorbancef luorescence

Ponds f r om bo t h s it e s poo l ed 0 - 551 0" 181 0 . 171A m o r i e n t p o n d s 0 . 5 9 8 0 . 5 8 8 0 . 4 1 3B Y U f a rm p o n d s 0 . 5 9 4 0 . 19 5 0 . 1 86

M o n i to r i n g o f D O a t A m o r i en t p o n d sT h e l o g - l i n e a r ( o r e x p o n e n t i a l ) p r o j e c t i o n t e c h n i q u e p r o v e d t o b e as u b s t a n t i a l l y m o r e a c c u r a t e m e t h o d o f p r e d i c t i n g d a w n D O t h a n t h el inea r p ro j ec t ion t echn ique (Tab le 4 ) . I n t he ca se o f t he s econd DOo b s e r v a t i o n m a d e 3 h a f t e r th e d u s k D O o b s e r v a t i o n (e a st a n d w e s tobse rva t ions ave raged) , t he l i nea r ex t r apo la t ion rou t ine unde re s t ima tedthe daw n D O in a ll 30 t r ia l s. T he l i nea r p red i c t i ons fo r a lag o f 3 h were ,on ave rage , 2 . 21 mg O: l i t e r -~ lower t han the obse rved pond ave rageD O ; a n d t h e p r e d i c t i o n w a s as m u c h a s 4 .5 3 m g l it e r- ~ l o w e r t h a n t h eobse rved dawn DO and , a t be s t , was on ly wi th in 0 . 9 mg l i t e r -~ o f t hea c tu a l d a w n D O .

In 27 o f t he 30 t r i a l s , t he dawn DO was unde re s t ima ted by the l og -l i nea r ex t r apo la t ion . Fo r DO m easu red 3 h a f te r dusk , t he ave rage abso -l u t e d i f f e r e n c e b e t w e e n t h e p r e d i c t e d a n d o b s e r v e d a v e r a g e p o n d D O(eas t and wes t obse rva t ions ave raged) a t dawn was 0 . 66 ; t he max imumabso lu t e d i f f e r ence (o r abso lu t e va lue o f t he r e s idua l ) was 1 . 42 and a tbes t t he p red ic t i o n was e s sen t i a ll y equa l to t he ob se rved DO .W h o l e p o n d r e s p i r a t i o n r a t e s a t t h e p o n d s m o n i t o r e d a t A m o r i e n tr a n g e d f r o m 0 . 3 2 4 t o 1 - 0 5 9 m g 0 2 l i t e r - ~ h - 1 ; w h e r e a s w a t e r c o l u m nresp i r a t i on r a t e s ( a s measu red in da rk bo t t l e s ) r anged f rom 0"035 to0 . 4 7 8 m g 0 2 l i t e r - t h - t ( T ab l e 5 ). W a t e r c o l u m n r e s p i ra t i o n r a t e ( o rp l a n k t o n r e s p i r a t i o n ra t e) a c c o u n t e d f o r 8 - 3 - 5 2 . 3 % ( 42 - 0% o n a v e r a g e)o f t h e w h o l e p o n d r e s p i r a t i o n r a t e . T h e d i f f e r e n c e b e t w e e n t h e w h o l ep o n d r e s p i r a t i o n r a t e a n d t h e p l a n k t o n r e s p i r a t i o n r a t e r a n g e d f r o m


11/18

Predic t ing n ight t ime D O loss: Par t I 201T A B L E 4Minimum (Min). Maximum (Max), and Mean Absolute Value of the Residuals from theLinear Extrapolation and the Log-Linear Extrapolation Techniques Applied to Amo-rient Prawn Pond Data, Oahu, June to September 1985 (The residual was the observeddissolved oxygen concentration (DO) minus the predicted DO (in mg O~ liter-f). Lagreferred to the number of hours between the time of the DO measurement at dusk andthe time of the second DO measurement. DO was measured from both the east and westsides of the pond; pond DO was the average DO of the west and east side observations)

L a g W e s t E a s t P o n dM i n M a x M e a n M i n M a x M e a n M in M a x M e a n

Linear extrapolation residuals (mg 02 liter- t )1 0"25 5"27 2"94 0"192 0"74 4'59 2"64 0"023 0-71 4'46 2"27 0"074 0"01 3"75 1'74 0'125 0'40 2"56 1-36 0"056 0'04 1"77 0-93 0"02

Log-linear extrapolation residuals (mg 021 0.28 3"34 1"19 0"212 0-03 2'06 0"86 0.053 0"03 1"83 0"73 0"024 0.19 1"35 0-65 0"055 0.02 0'94 0"48 0.016 0.05 0"60 0'34 0'02

5.95 3.39 0.32 5.52 2.975.18 2.37 0.57 5.52 2.575.18 2.04 0-90 4.53 2.214.69 1.68 0.43 3.74 1.693.97 1.28 0.39 3.08 1.322.33 0.79 0.01 1.91 0.85liter- J )5'66 1'68 0'22 2'46 1'162"32 0"88 0"11 1"76 0"802"17 0"78 0"00 1"42 0"66

2"32 0"69 0"07 1"12 0"561"82 0-52 0"04 1"13 0"431'15 0"34 0"02 0"70 0"27

abou t 0.19 to 0"80 mg O, l i ter- J h- Nof DO. The contr ibut ion of prawnrespiration to the whole pond respiration rate was minimal; Losordo(1980) est imated the prawn respirat ion rate for Amorient ponds to bebetw een 0.04 and 0.07 mg O, l i ter-~ h-~. We estima ted ,the sedim entrespiration by subtracting 0.05 mg li ter-~ h-] (estimate for prawn res-pirat ion) from the difference between the whole pond respirat ion and thewater column respiration. Sediment respiration rate ranged from 0.136to 0.748 with a mea n o f 0.324 mg O~ lite r- ~ h- l

DISCUSSION

The Boyd-Romaire-Johnston model descr ibed above, in which d i f fu-sion, plankton respiration, sediment respiration, and respiration of thecultured or ganism s are estim ated individually, was inappro priat e for usewith Hawaiian prawn ponds. Rom aire (1979) p ointed out that the bases


12/18

202 C. P . M a d e n f ia n , G . ' L . R o g e r s , A . W . F a s t

T A B L E 5W hole Pond Respiration R ate (W PR ) and Plankton Respiration R ate (PR ) at Tim e of100% D issolved Oxygen Saturation for Amorient Prawn Ponds, Oahu, Jun e to Septem-ber 1985 (Sediment respiration rate (SR) was equal to W P R - P R - 0 .05. PR/W PR rep-resented the p lankton respiration rat e fraction of the wh ole pon d respiration rate. Datewas fo r start of sampling period)

D a t e P o n d T e m p . a t R e s p i r a ti o n r a te i n P Rsa tura t ion m g 0 ,_ l it re - ~ hr -

( C) WI 'RWPR PR SR

6 June 85 D17 25"9 0"745 0.278 0.418 0.372DI8 25"8 0.324 0.138 0.136 0.427

8Jun e 85 D17 26.6 0.827 0.301 0-476 0.364D18 26.3 0.375 0.157 0-169 0.417

13 June 85 D17 26.5 0.824 0.270 0.504 0-328D18 25.4 0.370 0.167 0.154 0.450

22 June 85 D17 25.2 0.677 0.295 0.332 0.435DI8 24.7 0.403 0-186 0-167 0.461

27 June 85 D17 27"9 0.925 0.478 0.397 0'517D18 27.4 0.426 0.190 0.186 0.446

11 July 85 D12 27.5 0.689 0.325 0.314 0.472DI 3 26.9 0.501 0.260 0.191 0.518

21 July 85 D12 26.4 0.830 0.361 0.419 0.435DI3 25'9 0.726 0.308 0.368 0.425

24 July 85 D11 27.7 0-579 0-200 0.330 0.344DI2 27.1 0.698 0.351 0.297 0.503

1 Aug 85 D12 27.1 0.863 0-396 0.417 0.459D13 26.9 0.742 0.315 0.377 0.425

6 Aug 85 D 17 25.2 0.820 0.359 I).411 0.437D18 25.2 0-396 0.166 I).180 0.420

8 Aug 85 D 12 26.5 0.871 (5.372 0.449 15.427D 13 26.2 0.685 0.304 0"331 0.44324 Aug 85 DI2 27.6 0-582 0.254 (5.277 0.437DI3 27.6 0.569 0.234 0-285 15.41131 Au g8 5 D17 25.3 0.878 0-404 0.424 0.460DI8 25-3 I).388 (5-181 0.157 (5-4667 Sept 85 D 17 25-7 0.750 0.392 0.308 0.523D18 25.7 0.411 0.190 0-171 0-46221 Sept 85 A18 24.9 1.059 0.261 0.748 I).247

AI 9 24.8 0.421 0.035 I).336 0.083Mean 26.2 0.645 0.271 [5.324 0.420Standard deviation 1.0 (5.204 0.097 /). 135 0.086


13/18

Predic t ing n ight t ime D O loss: Par t I 203fo r success o f t he m ode l w ere : (1 ) a s t rong r e l a t i onsh i p be t w een secch id i s c d e p t h a n d p l a n k t o n r e s p i r a t i o n r a t e a n d ( 2 ) p l a n k t o n r e s p i r a t i o nr a t e b e i n g t h e m a j o r c o m p o n e n t c o n t r i b u t i n g t o n i g h t t i m e D O l o s s( p l a n k t o n r e s p i r a t i o n a c c o u n t e d f o r, o n a v e r a g e , a b o u t 8 0 % o f t h e n i g h tt im e d r o p i n D O ) . I t a p p e a r e d t h a t n e i th e r o f th e s e t w o c o n d i t i o n s w e r em e t i n H a w a i i a n p r aw n p o n d s .In gene ra l , s ecch i d i sc dep t h w as no t a r e l i ab l e i nd i ca t o r o f p l ank t onr e s p i r a t i o n i n H a w a i i a n p r a w n p o n d s . T h e r e w a s s u b s t a n t i a l , u n e x -p l a i ned va r i a t i on i n r e sp i r a t i on r a t e i n H aw a i i , pa r t i cu l a r l y fo r m oret u r b id w a te r. T h i s i n c o n g r u i t y b e t w e e n A l a b a m a a n d H a w a i i c o u l d h a v ebeen due l a rge l y t o d i f f e rences i n t u rb i d i t y be t w een t he t w o l oca t i onsand t he na t u re o f t he t u rb i d i t y . Secch i d i sc dep t hs u sed i n Rom ai re ' sr eg re s s i on an a l ys i s r anged f rom 17 to 153 cm ; w h i l e t he r ange o f s ecch id i sc dep t hs fo r t h i s s t udy w as f rom 6"5 t o 56 cm , ye t the r e sp i r a t i on r a t ef o r a g iv e n s ec c h i di sc d e p t h a n d t e m p e r a t u r e w a s h i g h e r f o r th e A u b u r np o n d s t h a n f o r t h e H a w a i i a n p r a w n p o n d s . T h e s e d a t a s u g g e s te d t h a t t h ebac kg rou nd t u rb i d i t y ( t u rb i d it y due t o f ac t o r s o t he r t han p l ank t on ) i n t heH a w a i i a n p o n d s i s h i g h e r t h a n t h a t i n A u b u r n p o n d s . A p p a r e n t l y , t h i sb a c k g r o u n d t u r b i d it y w a s r e la t iv e l y c o n s t a n t a m o n g t h e d i ff e r e n t p o n d sa n d r e m a i n s c o n s t a n t w i t h t i m e i n A l a b a m a . H o w e v e r , t h e b a c k g r o u n dt u r b i d i t y d i d n o t a p p e a r t o b e u n i f o r m a m o n g H a w a i i a n p r a w n p o n d s .T h e a b o v e d i s c u s s i o n w a s b a s e d o n t h e a s s u m p t i o n t h a t f o r a g i v e nr e g io n ( A l a b a m a o r H a w a i i ), r e s p i ra t io n r a te w a s u n i f o r m a m o n g p o n d sfo r a g i ven un i t o f p l an k t on t u rb id i ty . O f cou r se , t he re w as t he poss i b i l i tyt ha t fo r a g i ven un i t o f p l ank t on t u rb i d i t y , t he r e sp i r a t i on r a t e w as no tu n i f o r m a m o n g t h e p o n d s b e c a u s e o f d i ff e r e n ce s in t h e p h y s i o lo g i c a ls t a t e o f t he p l ank t on o r d i f f e rences i n t he p l ank t on spec i e s com pos i t i onb e t w e e n p o n d s . A n o t h e r f a c t o r to c o n s i d e r w h e n l o o k i n g a t d i f fe r e n c e sb e t w e e n t h e p o n d s i n H a w a i i a n d t h o s e i n A l a b a m a w a s w i n d s p e e d .W i nd ve l oc i ti e s a t the A ub urn s it e w ere r e l a ti ve l y l ow , w h i l e i n H aw a i it he t r adew i nds b l ow yea r round w i t h va r i ab l e i n tens i ty . W i nd can causere suspens i on o f s e t t l e ab l e m a t e r i a l , t hus i nc reas i ng t u rb i d i t y . A dd i t i on -a l l y . t he phy t op l ank t on spec i e s com pos i t i on w as no t ab l y d i f f e ren t :d i a t o m s w e r e c o m m o n i n H a w a i i a n p r a w n p o n d s ( R . Y o r k , p e r s. c o m m . ,H a w a i i In s t it u t e o f M ar i ne B i o l ogy , U n i v . H aw a i i , K a neoh e , H I ) bu t w e rer a r e i n A u b u r n p o n d s (C . B o y & p e r s . c o m m . . D e p t o f F i sh e r i e s a n dA l l ie d A q u a c u l t u r e s . A u b u r n U n iv . , A u b u r n , A L ) .

T h e g o o d f it t o d a t a fr o m p o n d s A F 3 a n d D 1 7 o n ly , s u g g e s te d th a tt he ba ckg rou nd t u rb i d i t y w as s im i l a r fo r t he se tw o p ond s an d t ha t it w asno t sub j ec t t o t he sam e va r i ab i l i ty a s the o t he r pon ds du r i ng t he s t udyp e r i o d , f o r s o m e r e a s o n . S i n ce p o n d s A F 3 a n d D 1 7 s h o w e d h i g h e rre sp i r a t i on r a t e s fo r a g iven secch i d isc v i si b il it y and t em pera t u re t han


14/18

204 C. P. M ade nfian , G. L. Rogers, A. W. Fasto t h e r p o n d s , a m o d e l e m p l o y i n g t h e r e g r e s s i o n e q u a t i o n b a s e d o n t h e s et w o p o n d s w o u l d t e n d t o u n d e r e s t i m a t e t h e m o r n i n g D O i n t h e o t h e rf o u r p o n d s s t u d i e d .

C h l o r o p h y l l a d e t e r m i n e d b y e x tr a c ti o n a n d m e a s u r in g a b s o r b a n c e o na spec t rop ho t om e t e r w as a lso no t a h i gh l y r e l iab l e i nd i ca t o r o f w a t e rco l u m n re sp i r a t i on . Pe rhaps t he r e sp i r a t i on r a t e pe r un i t o f ch l o ro phy l l ava r i ed be t w ee n spec i e s an d b e t w e en d i f f e ren t phys i o l og i ca l s t a te s o f t hesam e spec i e s . I n v i v o f l u o r e s c e n c e w a s n o t a g o o d p r e d i c t o r o f p l a n k t o nre sp i r a t i on r a t e . L i m i t a t i ons o f i n v i vo f l uo re scence a s a p red i c t o r o fc h l o r o p h y l l a h a v e b e e n n o t e d b y L o f t u s a n d S e li g er ( 1 9 7 5 ) a n d S t ri ck -l a n d ( 1 9 6 8 ) . C o n f o u n d i n g t h e c o r r e l a t i o n b e t w e e n i n v i vo f l uo re scenceand r e sp i r a t i on r a te , aga i n , w e re spec i e s d if f e rences and d i f f e ren t phys i o -l og ica l s t a t e s . N o t t o be ove r l ook ed w as t he con t r i bu t i on o f bac t e r i a lr e sp i r a t i on t o t he p l ank t on r e sp i r a t i on ; bac t e r i a l r e sp i r a t i on m ay havec o n t r i b u t e d s u b s t a n t ia l ly to t h e w a t e r c o l u m n r e s p ir a ti o n . C h l o r o p h y l l ad e t e r m i n a t i o n b y e x t r a c t i o n o r i n v i vo f l uo re scence w ou l d no t be sens i -t ive to a s se s s i ng m os t bac t e r i a popu l a t ions .I t w a s h o p e d t h a t m e a s u r i n g t u r b i d i t y b y t h e H a c h m e t e r , a n d t h u savo i d i ng t he sub j ec t i v i t y o f m easu rem en t by secch i d i sc dep t h , w ou l d

l ead t o a s t rong r e l a t i onsh i p be t w een t u rb i d i t y and r e sp i r a t i on r a t e .H ow eve r , t u rb i d i t y , r ega rd l e s s o f how i t w as m easu red , d i d no t fo recas tp l an k t on r e sp i r a t i on r a t e w e ll.M o r e d e t r i m e n t a l t o t he u s e f u ln e s s o f t h e B o y d m o d e l i n H a w a i i th a nn o t h a v i n g f o u n d a n a c c u r a t e i n d i c a t o r ( a c c u ra t e a n d e a s il y m e a s u r e d b yt he f a rm er ) o f p l ank t on r e sp i r a t ion , w as t he ev i den ce i nd i ca t i ng t ha t thew a t e r c o l u m n r e s p i r a t i o n w a s n o t t h e m a j o r c o n t r i b u t o r t o t h e w h o l epond re sp i r a t i on r a t e . The ave rage ben t h i c r e sp i r a t i on r a t e f rom t he Fas tet al . (1983) s t udy o f 221 m g 02 m g--" h -~ fo r a l - ac re pon d w i t h ave r -age dep t h o f 0 .75 m co r re sponded t o a r a t e o f 0 .299 m g O ~ l i t e r -~ h - J ;t h is f igu re w as i n f a ir l y c l o se ag re em en t w i t h t he ave rage ben t h i c r e sp i r a -t i on r a t e e s t i m a t ed f rom our s t udy a t A m or i en t (0 .324 m g O , l i t e r -h - t ) .

Losordo ' s c l a i m t ha t t he w a t e r co l um n re sp i r a t i on w as t he m a j o rcon t r i bu t o r t o D O dec l i ne in the A m or i en t p ond s w as no t j u s ti f ied si ncet he d i ffu s i on e f f ec t w as no t acco un t ed fo r. In Lo so rd o ' s s t udy , w h en D Odro pp ed be l ow sa t u ra t i on i n t he pond s , and i f w i nd speeds w ere subs t an -t ia l ( as Lo rso do r epo r t ed ) , t hen oxyg en w ou l d d i f fu se in t o the pon d a t asubs t an t i a l r a te . Th us , i t is li ke l y t ha t m ore oxygen w as co nsum ed ove r -n i gh t by t he w ho l e pond t han i nd i ca t ed by t he d i f f e rence be t w een duskand da w n D O m easu rem en t s . Se d i m e n t r e sp i r a t i on r a t e w as d i ff i cu l t t os t udy and t o t he know l edge o f t he au t ho r s , no r eg re s s i on equa t i on us i ngs o m e e a s i ly - m e a s u r e d i n d i c a to r v a r ia b l e s a n d t e m p e r a t u r e h a s b e e n


15/18

Predicting night t im e D O loss: Part I 205d e v e l o p e d t o e x p l a i n a h i g h p e r c e n t a g e o f v a r i a t io n in s e d i m e n t r e s p i ra -t i o n d a t a . S e d i m e n t r e s p i r a t i o n r a t e e s t i m a t e s f r o m o u r s t u d y a tA m o r i e n t , as w e l l a s t h e s e d i m e n t r e s p i r a ti o n o f H a w a i i a n p r a w n p o n d sm e a s u r e d b y F a s t e t a l . ( 1 9 8 3 ) a n d G a r z a ( u n p u b l i s h e d m a n u s c r i p t ) ,s h o w e d h i g h v a ri a bi li ty . B o y d u s e d o n e s e d i m e n t r e s p i r a t io n r a t e t op r e d ic t s e d i m e n t r e s p ir a ti o n f o r al l t h e A u b u r n p o n d s . T h i s m e t h o d w a sa d e q u a t e f o r A u b u r n p o n d s s in c e , a p p a r e n t l y , t h e r e w a s l it tl e v a r i a t i o n i ns e d i m e n t r e s p i r a ti o n r a t e b e t w e e n p o n d s a n d t h e b e n t h i c r e s p i r a t io n w a sa r e la ti v el y u n i m p o r t a n t c o m p o n e n t o f w h o l e p o n d r e sp i ra t io n . H o w -e v er , t h e u s e o f a m e d i a n o r a v e r a g e d s e d i m e n t r e s p i r a t i o n r a te t o p r e d i c ts e d i m e n t r e s p i r a t i o n f o r a l l p o n d s w o u l d y i e l d i n a c c u r a t e r e s u l t s f o rH a w a i i a n p r a w n p o n d s a t A m o r i e n t ; m a i n l y d u e t o t h e h i g h v a r ia b i li tya n d t h e i m p o r t a n c e o f b e n t h ic r e s p i r a ti o n in H a w a i i a n p o n d s .T h e m e t h o d o f a c c o u n t in g fo r d i f fu s io n i n B o y d 's m o d e l w a s a l s oi n a p p r o p r i a t e f o r H a w a i ia n p r a w n p o n d s , p a r t ic u l ar ly at t h e A m o r i e n t(windy) s i t e . Wind speeds ave raged f rom abou t 4 . 5 t o 10 m s -~ du r ingt h e n i g ht fo r t h e D O m o n i t o r in g st u d y a t A m o r i e n t. B o y d u s e d t h ea p p r o a c h o f S c h r o e d e r ( 1 9 7 5 ) , in w h i c h t h e % s a t u r a t i o n o f t h e p o n d a td u s k w o u l d b e u s e d t o f o r e c a s t t h e o v e r n i g h t g a in o r l o s s o f D O b y d i ff u -s io n . T h e p o n d s f o r S c h r o e d e r ' s s t u d y w e r e s u b j e c te d t o r e l at iv e l y l o ww i n d sp e e d . S u p p o s e a p o n d w a s m o r e t h a n 1 2 0 % D O s a t u r a te d a t d u s k( n o t u n c o m m o n f o r A m o r i e n t o r B Y U p o n d s ) . U s i n g S c h r o e d e r ' sa p p r o a c h , t h e n e t e f fe c t f o r d i f f u si o n o v e r n i g h t w o u l d b e p r e d i c t e d a s al os s o f D O f r o m t h e p o n d . H o w e v e r , a t th e A m o r i e n t p o n d s ( s u b je c t edt o s t r o n g w i n d s a t t im e s ), a p o n d s u p e r s a t u r a t e d i n D O a t d u s k m a y ' d r o pw i t h in a fe w h o u r s a f t er d u s k t o b e l o w t h e D O s a t u r a t i o n p o i n t a n d t h u sbe u nd e r sa tu ra t ed in DO fo r mo s t o f the n igh t . I n t h is ca se , t he ne t ove r -n i g h t ef fe c t o f d i ff u s io n o n t h e p o n d m a y h a v e b e e n a g a in o f D O i n th ep o n d ( se e M a d e n j i a n e t a l . , 1987) .

T h e l in e a r e x t r a p o la t i o n m e t h o d e n d o r s e d b y B o y d w a s a p o o r p r e -d i c t o r o f d a w n D O i n H a w a i i a n p r a w n p o n d s . T h e l o g - li n e a r p r o j e c t i o nt e c h n i q u e w a s s u p e r i o r t o t h e l i n e a r t e c h n i q u e f o r p r e d i c ti n g d a w n D Oa t th e A m o r i e n t p o n d s . W e m a y h a v e e x p e c t e d a n e x p o n e n t i a l d e c l i n e i nD O dur ing n igh t t ime a t Am or i en t (windy s it e) becau se 'o f : (1 ) d i f fus ione f f ec t and , l e s s im por t an t ly , (2 ) the o ve rn igh t d ro p in wa te r t em pera tu re .D i f f u s io n o f o x y g e n o u t o f t h e p o n d w o u l d o c c u r m o r e q u i c k ly th e h i g h e rt h e D O w a s a b o v e t h e D O s a t u r a t i o n l ev e l; t h e m o r e t h e D O w a s b e l o wthe sa tu ra t ion l eve l, t he f a s t e r oxygen wo u ld d i f fuse i n to t he po nd . T hus ,d i f fu s i o n w o u l d a c t t o d e c r e a s e t h e r a t e o f d e c li n e o f D O i n th e p r a w np o n d s , a s t h e n i g h t p r o g r e s se d . A d d i t i o n a l ly , a s t e m p e r a t u r e d r o p p e d( o n a v e r a g e a b o u t 2 - 3 C f o r A m o r i e n t p o n d s d u r i n g t h e s t u d y ) , s o t o ow o u l d t h e w h o l e p o n d r e s p i r a t io n r a te .


16/18

206 C. P. M adenj ian , G. L . Rogers, A . W. Fas tN ote tha t t he l og - l i nea r ex t r ap o la t ion t echn ique was in sens i t ive t owind speed . Ana ly s i s o f t he r e s idua l s (d i ff e r ence be tw een the obse rveda n d p r e d i c t e d v a l u e s ) f r o m a p p l i c a t i o n o f t h e l o g - l i n e a r m e t h o d t o

A m o r i e n t p o n d s r e v e al e d t h a t t h e d a w n D O w a s m o r e a c c u ra t el y e st i-m a ted (usua l ly un de re s t im a ted to a l e s se r deg ree ) as wind speedd e c r e a s e d . A s w i n d s p e e d i n c r e a s e d , w e w o u l d e x p e c t t h e d i f f u s i o ne f fe c t t o b e s tr o n g e r. T h u s , t h e d e g r e e o f c u r v a t u r e o f t h e D O d e c l in ew o u l d b e i n f l u e n c e d b y w i n d s p e e d . W i t h i n c r e a s i n g w i n d s p e e d , D O(assuming supe r sa tu ra t ion a t dusk ) wou ld a r ive a t t he sa tu ra t ion l eve lm o r e q u i c k ly ( s ho w a s h a r p e r d e c l i n e to s a t u r a ti o n ); b u t w h e n b e l o w D Osa tu ra t ion , a s wind speed inc reased , DO wou ld no t dec rease a s qu ick ly .T h e e f fe c t w o u l d b e m o r e o f a b e n d i n t h e o v e r n i g h t D O c u r v e as w i n ds p e e d i n c r e as e d .T h e l o g - li n e a r e x t r a p o l a t i o n t e c h n i q u e w a s n o t t e s te d f o r s t il l c o n d i -t i ons (wind speeds nea r ze ro ) . I f we a s sumed the d i f fus ion e f f ec t t o beneg l ig ib l e w he n w ind speed i s ne a r ze ro ( a s suming a neg l ig ib l e dec l ine i nt e m p e r a t u r e ) , a l in e a r d e c li n e in D O d u r i n g t h e n i g h t w o u l d h a v e b e e npred ic t ed . In t he case o f s ti ll con d i t i ons , we m ay have e xpec t ed the l og -l i n e a r e x t r a p o l a t io n t o s u b s t an t i al ly o v e r e s t im a t e t h e d a w n D O ( p a rt ic u -l a r ly if r e sp i r a t i on r a t e o f t he po nd was h igh ). P red ic t ion o f a ' s af e ' daw nD O l e v el w h e n i n f a c t t h e d a w n D O l e ve l w a s l o w ( say , b e l o w 2 m g O 2l i t e r - l ) w o u l d r e p r e s e n t a n u n d e s i r a b l e s i t u a t i o n t o t h e p r a w n p o n dm a n a g e r . A m o d e l t h a t i n c o r p o r a t e d t h e d i f fu s i o n e f fe c t a s a f u n c t i o n o fw i n d s p e e d w o u l d p r o b a b l y fo r e c a st d a w n D O m o r e a c c u r a te l y t h a n th el o g - li n e a r e x t r a p o l a t i o n m e t h o d .

S U M M A R Y

T h e B o y d e t a l . ( 1 9 7 8 ) m o d e l , i n w h i c h t h e o v e m i g h t c h a n g e i n p o n dD O w a s m o d e l e d a s a f u n c t i o n o f f o u r c o m p o n e n t s : p l a n k t o n r e s p i r a -t i on , s ed imen t r e sp i r a t i on , d i f fus ion , and r e sp i r a t i on o f t he cu l tu redo r g a n i s m s , w a s i n a d e q u a t e f o r H a w a i i a n p r a w n p o n d s . T h e m e t h o d su s e d b y B o y d e t a l . ( 1 9 7 8 ) t o p r e d i c t p l a n k t o n r e s p i r a t i o n , s e d i m e n tr e sp i r a t i on , and the d i f fus ion e f f ec t were i naccura t e when app l i ed top r a w n p o n d s i n H a w a i i . F u r t h e r m o r e , t h e d a t a f r o m o u r s t u d y a t A m o -r i en t su g g e st e d t h a t s e d i m e n t r e s p i r a t i o n w a s a n i m p o r t a n t c o m p o n e n t tot h e w h o l e p o n d r e s p i r a t io n r a t e i n a t l e a st s o m e o f th e H a w a i i a n p r a w np o n d s . T h e n i g h t t im e d e c l i n e o f D O a t A m o r i e n t (K a h u k u , a w i n d y si teo n O a h u ) w a s b e t t e r c h a r a c t e r i z e d a s e x p o n e n t i a l r a t h e r t h a n l in e a r. T h el o g - l i n e a r ( o r e x p o n e n t i a l ) e x t r a p o l a t i o n t e c h n i q u e p r o d u c e d f a i r l ya c c u r a t e e s t i m a t e s o f d a w n D O f o r t h e A m o r i e n t p o n d s . H o w e v e r , i t s


17/18

Predicting night time D O loss: Pa rt I 207use m ay be l imi t ed s ince i t does no t acc oun t fo r t he d i f fus ion e f f ect a s af u n c t i o n o f w i n d s p e e d .

A C K N O W L E D G E M E N T SG e r a l d A k i y a m a i s a c k n o w l e d g e d f o r h i s e x p e r t a d v i c e o n l a b o r a t o r yp r e p a r a t i o n a n d o n m a i n t e n a n c e a n d o p e r a t i o n o f t h e e q u i p m e n t .D a r w i n B o h n e t a n d E t i E v e s a s s i st e d w i t h f ie l d a n d l a b w o r k a t t h e B Y Uf ac il it y. W e g r a te f u ll y a c k n o w l e d g e R o g e r F u j i o k a a n d H e n r y G e e o f t h eW a t e r R e s o u r c e s R e s e a r c h C e n t e r , U n i v e r s i t y o f H a w a i i f o r u s e o f th e i rf l u o r o m e t e r a n d B O D o x y g e n p r o b e . R o b e r t Y o u n g o f O c e a n ic I n s ti tu t e( W a i m a n a l o , O a h u ) k i n d l y l o a n e d u s s e v e r a l f l u o r o m e t e r l a m p s . W i n ds p e e d d a t a w e r e p r o v i d e d b y J a m e s B a c , S u e ji Y a n o , a n d G e o r g e C u r t iso f th e H a w a i i N a t u r a l E n e r g y I n s ti tu t e , U n i v e r s i t y o f H a w a i i. T h a n k s t oK e n K a m i y a , m a n a g e r o f t h e B Y U f ar m , a n d E d M c S w e e n y , m a n a g e r o ft h e A m o r i e n t f a r m , f o r t h e i r c o o p e r a t i o n . T h i s w o r k i s a r e s u l t o fr e s e a rc h ( 'D e v e l o p m e n t o f P on d O x y g e n M a n a g e m e n t D e v i ce s a n d P r e -d i c t i v e P r o c e d u r e s f o r I n c r e a s i n g P r a w n P r o d u c t i o n ' p r o j e c t , A / R - 1 9 )s p o n s o r e d , i n p a r t , b y t h e U n i v e r s it y o f H a w a i i S e a G r a n t C o l l e g e P r o -g ra m u n d e r I n s ti tu t io n a l G r a n t N o . N A 8 1 A A - D - 0 0 0 7 0 f r om N O A A ,O f f ic e o f S e a G r a n t , D e p a r t m e n t o f C o m m e r c e ; a n d s p o n s o r e d , in p a rt ,b y t h e A q u a c u l t u r a l D e v e l o p m e n t P r o g r a m o f H a w a i i ( C o n t r a c t N o .1 7 6 6 3) . T h i s is S e a G r a n t p u b l i c a ti o n U N I H I - S E A G R A N T - J C - 8 7 - 0 4a n d H a w a i i In s t it u t e o f M a r i n e B i o l o g y C o n t r i b u t i o n N o . 7 2 6 .

R E F E R E N C E SBoyd, C. E., Romaire, R. E & Johnston, E. (1978). Predicting early morningdissolved oxygen con centrations in c hann el catfish ponds. Trans . A m . Fish .Soc., 1 0 7 , 4 8 4 - 9 2 .Costa-Pierce, B. A., Craven, D . B., Karl, D. M . & L aw s, E. A . (1984). C orrela-t ion of in situ respiration rates and microbial biomass in prawn (Macro-brachium rosenbergii) ponds. Aq u a cu l tu re , 3 7 , 1 5 7 -6 8 .Environm ental Protect ion Agency (19 83). Meth o d s fo r Ch emica l An a ly s i s o fWater an d Wastes, EPA-600/4-79-020.Fast, A. W., Barclay, D. K. & Akiyama, G. (1983). Artificial circulation ofHawaiian prawn ponds~ U niv. Ha wa ii Sea Gran t College Program, UNIHI-SEAGRANT-CR-84-01.Jeffrey, S. W. & Hum phrey, G. E ( 1975 ). New spe ctrop ho tom etric equations fo rdetermining chlorophylls a, b, cj and c~ in higher plants, algae and naturalphytoplankton. Biochem. Physiol . Pfl . , 167, 191-4.


18/18

208 C. P. M adenjian, G. L. Rog ers, A. W. FastLof tus , M . E . & Seliger, H . H. (1975) . So m e l imi ta t ions o f the in vivo f luoresc-en ce t ech n iq u e . Chesap eake Sc i. , 1 6, 7 9 - 9 2 .Lo so r d o , T . M. (1 9 8 0 ) . A n in v es tig a tio n o f t h e o x y en d em an d m a te r i a ls o f th e

wa te r co lu m n in p r awn g r o w- o u t p o n d s , MSc . Th es i s , Un iv . o f Ca l i f o r n i a ,Davis .M adenj ian , C. P ., Ro gers , G. L . & Fast , A. W. (1987) . Pred ic t ing n igh t t im e d is-so lv ed o x y g en lo ss i n p r awn p o n d s o f Hawa i i : Pa r t I I. A n ew m e th o d . A q u a -cultu ral Engineering, 6 , 2 0 9 - 2 5 .Ro m ai r e , R . P . ( 1 9 7 9) . M o d e l in g th e d y n am ics o f d is so lv ed o x y g en in ch an n e lc a tf is h p r o d u c t i o n p o n d s , P h D . T h e s is , A u b u r n U n i v .Sch r o ed e r , G . L . ( 1 9 7 5 ). N ig h t t im e m a te r ia l b a l an ce f o r o x y g en in f ish p o n d srece iv ing o rgan ic wastes . B a m i d g eh , 2 7 , 6 5 - 7 4 .Sta t i s t ica l Analys is System (1982) . SAS User's Guide: Statist ics, SAS Ins t i tu teI n c. , Ca r y , No r th Ca r o l in a .S t r i ck l an d , J . D . H . ( 1 9 6 8 ) . Co n t in u o u s m easu r em en t o f in vivo ch lorophyl l ; ap r ecau t io n a r y n o te . Deep-Sea Res . , 1 5 , 2 2 5 - 7 .

Date post:	03-Apr-2018
Category:	Documents
Upload:	jorge-rodriguez
View:	216 times
Download:	0 times

Madenjian 1987 Aquacultural-Engineering

Documents