Motoh, Hiroshi

English

Southeast Asian Fisheries Development Center, Aquaculture Department Institutional Repository (SEAFDEC/AQD Institutional Repository )

AQUACULTURE FISHERIES IN JAPAN AND IN THE PHILIPPINES -  A COMPARISONH iro s h i MOTOHAt the  o u ts e t, I  would l ik e  to  express my thanks fo r  the  p r iv i le g e  given me to  be w ith  you th is  m orning. MAGANDANG UMAGA PO SA INYONG LAHAT.I  would l ik e  to  speak th is  morning on the  to p ic  "AQUACULTURE FISHERIES IN JAPAN AND IN THE PHILIPPINES -  A COMPARISON". In  Japan, we have two most popu la r A quacultu re methods, namely: Pond C u ltu re  method and Marine C u ltu re  method.In  the  Pond C u ltu re  method, the f r y  ob ta ined from the h a t­che ries  by a r t i f i c i a l  p ropagation  techniques or from n a tu ra l sources are being reared in  the  c u ltu re  ponds up to  m arketable s ize  The c u ltu re  o f  Y ellow  t a i l s  and Red Sea Breams are good examples. On the  o the r hand in  th e  Marine C u ltu re  method, m illio n s  o f  f r y  from a r t i f i c i a l  breeding in  h a tch e rie s  are being lib e ra te d  in to  the  open sea and le t  them grow up to  m a tu r ity  under n a tu ra l con­d it io n s ,  in s te ad  o f  s to ck in g  them in  c u ltu re  ponds. In  o th e r words, th is  type o f f is h e ry  is  a com bination o f  a r t i f i c i a l  and n a tu ra l methods and is  sometimes c a lle d  "Farming F is h e ry " . Un­l i k e  in  Pond C u ltu re , wherein the  products belong to  the  pond owners o n ly , in  the  Marine C u ltu re  method, the  products belong to  n a tu re , hence, to  everybody.The pond C u ltu re  in d u s try  is  no t as popu la r in  Japan as, i t  is  in  the  P h il ip p in e s . Th is is  due to  the  s c a rc ity  o f  c u l t i ­vab le  pond areas. In  fa c t ,  we u s u a lly  make use o f  e x is t in g  s a l t  beds and convert them in to  c u ltu re  ponds. Thus, i f  we ju s t  depend upon Pond  C u ltu re  method, consumption demand fo r  marine products cou ld  never be met.No. 2R e a liz in g  the  l im ita t io n s  in  Pond C u ltu re  in d u s try , Marine C u ltu re  method was developed by the  Japanese ten  years ago to  he lp  meet the  demands fo r  marine products and to  re p le n is h  the  decl in in g  popu la tions  o f  marine resources in  n a tu ra l waters due to  overex­p lo it a t io n  and due to  in d u s t r ia l  p o l lu t io n  o f  f is h in g  and spawning grounds. However, in  o rder to  e f fe c t iv e ly  re p le n is h  the  s tock  in  the  sea, the re  is  the  problem o f secu ring  m il l io n s  o f f r y  fo r  s to ck ­in g . Ten years ago, th is  g rea t q u a n t ity  o f  f r y  needed fo r  s to ck in g  could not be produced a r t i f i c i a l l y .  T h us , du ring  th a t tim e , pond c u ltu re  and marine c u ltu re  f is h e r ie s  depended m ain ly  upon n a tu ra l sources. A fte r  a few yea rs , however, mass seed p rodu c tion  techn ique o f  Kuruma eb i ' s c ie n t i f i c  name, Penaeus jap on icu s) was e s ta b lis h  by the  Seto In la n d  Sea F ish  Farming A sso c ia tio n  researchers under the  le a de rsh ip  o f  D r. Motosaku F u jin ag a . As a r e s u lt  o f  the  p ionee ring  work o f Dr .  Fu jinaga on Kuruma e b i, a r t i f i c i a l  propagation  techniques o f o th e r species -  fo r  example, o the r shrim ps, crab , abalone, f l a t ­f is h  and ro c k f is h  -  were s tu d ie d  and e s ta b lis h e d . The re s u lts  o f the  researches o f f is h e r ie s  u n iv e rs it ie s  and f is h e r ie s  la b o ra to r ie s  supported by the Japanese government, were propagated to  P re fe c tu ra l F is h e rie s  E xpe riment a l  S ta tio n s  and to  f is h e r ie s  coopera tives loca ted  th roughout Japan.At present we can produce two hundred m il l io n  f r y  o f  Kuruma eb i o r prawn and a lso  seve ra l m i l l io n  f r y  o f  o th e r e d ib le  shrim ps, crab , abalone, rock  f is h ,  in  o the rs  in  a ye a r. By the  way, which is  more p r o f i ta b le  fo r  fisherm en, Pond C u ltu re  o r Marine C u ltu re ? In  my o p in io n , i f  we app ly the  modern techniques in  a r t i f i c i a l  p ro ­pagation  in  la rg e  sc a le , and i f  we can use cheap, u n p o llu te d  and la rg e  pond areas, pond c u ltu re  f is h e ry  is  more p r o f i ta b le  than ma­r in e  c u ltu re  f is h e ry .  I t  is  because, in  pond c u ltu re  method, we can exte rm ina te  the  p reda to rs  and com pe tito rs  e a s ily  and a lso  ponds cou ld  be e a s ily  managed than the  n a tu ra l sea. In  the case o f  the marine c u l tu r e method, most o f  the f r y  l ib e ra te d  in to  the  sea are under the  mercy o f  p re d a to rs . And a ls o , i t  is  a p i t y  th a t the re  is  no good method y e t on how to  eva lua te  the  re s to c k in g  e f fe c ts .No. 3In  s p ite  o f th is  s i tu a t io n ,  the  fisherm en are fo rced  to  re lease  t h e i r  f r y  in to  the  open sea due to  Japan's geograph ica l l im ita t io n s  and a lso  due to  p o l lu t io n  o f  sha llow  coa s ta l areas.The fo llo w in g  are the  steps taken in  the  marine c u ltu re  method: (T h is  is  i n  the  case o f  Kuruma e b i, Penaeus ja p o n icu s . )Step I .  A r t i f i c i a l  Seed P roduction  in  the  HatcheryThe mother shrimps used fo r  spawning are u s u a lly  b ig  shrimps w eighing over 50 grams on the  average. The la rva e  hatched out are reared a r t i f i c i a l l y  up to  s to c k in g  s iz e  o r 20 mm body len g th  fo r  about 30 days. P re s e n tly , we can produce two hundred m i l l io n  f r y  o f  the above-mentioned s ize  in  a yea r. On the  average one hundred thousand f r y  o r an e q u iv a le n t o f  30 percent s u rv iv a l ra te  from n a u p li i  la rva e  to  f r y  s tage, cou ld  be produced from one spawner. On the o th e r hand, under n a tu ra l c o n d it io n s , on ly  a sm a ll percentage o f th e  la rva e  can s u rv iv e , thus I  th in k  the  e f fe c t  o f a r t i f i c i a l  re a r in g  is  tremendous. We u s u a lly  use 200 to  500-ton concrete tanks in  the  h a tch e ry .Step I I .  Rearing in  the  Nursery PondsThe f r y  from the  h a tch e ry , owing to  i t s  ve ry  sm a ll s iz e , are not d i r e c t ly  re leased in to  the  sea bu t are f i r s t  reared in  the  nursery  ponds. Th is is  to  t r a in  them to  escape from enemies, t r a in  them to  search and catch th e ir  foods and to  a c c lim a tiz e  them to  th e ir  n a tu ra l h a b ita t  in  the  sea. I t  is ,  in  s h o r t ,  a t r a in in g  fo r  s u rv iv a l.  U sua lly  we keep the  f r y  in  the  nu rsery  fo r  one pr two weeks which is  s itu a te d  in  sha llow  co a s ta l waters surrounded w ith  a r t i f i c i a l  d ike s .Step I I I .  Release o f  Fry in to  the  Sea.G en e ra lly , shrimps are n o c tu rn a l in  h a b it  and are u s u a lly  observed in h a b it in g  sha llow  co a s ta l waters to  escape from b ig  pre­d a to rs . Thus, we re le ase  the f r y  in to  the  sea du ring  n ig h t tim e o r du ring  the  low est t id e .  Furtherm ore, we appeal to  fisherm en to  r e f r a in  from ca tch ing  the  newly re leased young shrim ps u n t i l  they reach m arketable s iz e .No. 4Step IV , Recapture o f  the  A du lt ShrimpsA fte r  about  s ix  months the  re leased shrimps reach m arketable s ize  o f about 15 cm in  body le n g th . Some o f the  shrimps m igra te  to  spawning grounds. I t  is  considered good, i f  fisherm en could catch th ree  percent o f the  to t a l  number o f  f r y  s tocked.Now, I  would l i k e  to  comment on the  Aquacu ltu re  F is h e rie s  in  the  P h il ip p in e s . F rank ly  speaking, I  th in k  the  pond c u ltu re  f is h e ry  in  the  P h ilip p in e s  has b r ig h te r  fu tu re  fo r  development than th a t in  J apan fo r  th e  fo llo w in g  reasons:1. The f is h  being reared  in  P h ilip p in e  ponds has h ig he r growth ra te  because w ater tem perature is  c o n s ta n tly  hijgh, from 27°C to  31°C and th a t f is h  o r shrimps could be c u ltu re d  th rough­out the  yea r,2. There is  le ss  p o l lu t io n  o f  co a s ta l waters by in d u s t r ia l  p la n ts  and sewage d is p o s a l, except fo r  a few areas,3 . There are vas t areas o f undeveloped mangrove swamps and e s tu a rie s  in  va rio u s  p a rts  o f  th e  c o u n try . A lso , the  p r ic e  o f  p o te n t ia l pond areas is  much cheaper than th a t in  Japan.4 . The spawning seasons o f u s e fu l f is h e s  are longer in  the P h ilip p in e s  than in  the  tem perate zones, thus more f r y  cou ld  be produced fo r  a longer p e r io d .5. Water management in  c u ltu re  pond could e a s ily  be done due to  wide range between low and h igh t id e s .  In  t h is  case, com­p e t i to rs  and p reda to rs  o f c u ltu re d  f is h  o r shrimps cou ld  e a s ily  be handled.6. La b -la b , which is  a conglom eration o f diaroms and zoo­p lank tons , grow n a tu r a l ly  in  nu rse ry  and c u ltu re  ponds which serves as a cheap supp ly  o f feeds fo r  Bangus and o th e r spe c ies . And,  7 . The p r ic e  o f sea foods is  h igh  and demand is  g re a t. In  connection w ith  the  above-mentioned ob se rva tio n s , I  would l ik e  to  suggest th a t a r t i f i c i a l  seed p rodu c tion  techniques best s u ite d  fo r  t r o p ic a l  and s u b - tro p ic a l zones co n d itio n s  be s tu d ie d  and e s ta b lis h e d , in  o rder to  f u l l y  develop the  f is h  pond in d u s try .No. 5I  would l ik e  to  suggest fu r th e r ,  th a t Bangus c u ltu re  and Sugpo c u ltu re  be g iven p r io r i t ie s  due to  the  fo llo w in g  reasons:1. Both species have h igh  market va lue and are in  g rea t demand.2. Both grow ra p id ly  in  ponds the  whole year round.3. Bangus are g e n e ra lly  he rb ivo rou s , s p e c i f ic a l ly  p la n k to n - fee de rs . Thus, pond owners cou ld  ju s t  apply both o rgan ic  and in ­o rgan ic  f e r t i l i z e r s  in  t h e i r  ponds to  grown n a tu ra l feeds. And,4. Bangus and Sugpo could be c u ltu re d  to g e th e r w ith o u t problems a t a l l .  Thus, h ig h e r y ie ld  per acre o f  pond cou ld  be expected.By the  way, the  AQUACULTURE DEPARTMENT o f SEAFDEC, South­east Asian Fisheries Development C enter, lo ca te d  in  Tigbauan, I l o ­i l o ,  and the M S U -In s titu te  o f  F is h e rie s  Research and Development in  Naawan, Misamis O r ie n ta l,  are now conducting researches i n   seed p roduc tion  and c u l t iv a t io n  o f  some va lu a b le  marine species, Sugpo ( s c ie n t i f i c  name, Penaeus monodon) , Long-legged G iant Prawn (Macrobrachium ro s e n b e rg ii) , Alimengo (S c y lla  s e r ra ta ) ,  Alimapag ( Portunus p e la g iftu s ) , O ysters, Seaweed and o th e r species o f h igh  economic va lu e s . I t  is  hoped th a t SEAFDEC would in  some day con­t r ib u te  to  the  f is h e r ie s  economic development o f  the  co u n try .I t  is  observed th a t p o pu la tion  growth increases remarkably around the  w o rld  every yea r. Twenty years from now, i t  is  e s t i ­mated th a t the  world p o p u la tio n  would reach the  f iv e  o r s ix  b i l l i o n  mark. S c ie n t is ts  b e lie v e  th a t th e  animal p ro te in s  requirem ents o f  the  increasing p o p u la tio n  could only be supported by the  sea.Thus, the  f u l l  development o f  aquacu ltu re  f is h e r ie s  in  the  P h ilip p in e s  w i l l  p lay  a major ro le  in  supp ly ing  the  p ro te in  needs o f  th e w o rld  in  the  near fu tu re .  Th is is  on ly  p o ss ib le  i f  both the  government and p r iv a te  sec to rs  jo in  hand in  hand to g e th e r in  the  w ise and e f f ic ie n t  u t i l i z a t io n  o f  our n a tu ra l marine resources.MARAMING SALAMAT PO.-oOo-

Aquaculture fisheries in Japan and in the Philippines - A comparison

https://repository.seafdec.org.ph/bitstream/10862/3395/1/MotohH1974.pdf

Aquaculture fisheries in Japan and in the Philippines - A comparison

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