TaBLE 2.4.—Annual production, live weight of animals in pounds per acre } 
Yield 
Animal (Average or 
range) 
Sea water, unfertilized: 2 
Fishponds, Philippines -_--_-------- Milkfishs=. 23222242 400-980 
ishponds, Franeé...._..2-...-... Grey mullet 2o...22- 300 
Pishpowds, Java_....-....-...-=-+ Wolisits iia 2 en sa R Sth eases 
| E1050 af =| Sym eae a eg cae (ERA Cee eee ae ee 40 
Richest coe eae ee ca ee em ee aoe ee ee 300 
Fishponds, Indonesia_-_-_----------- Milkfisht2> 223222240 140 
Prawnsees= ss 25a 46 
Wild fishes ssa 23 
North Sea, W9222 22222025222 See | T=) 0 eae On aR 21.3 
World marine fishery 3_____________]____- (0 0 ree es oar cea 0. 45 
PAV ATi ea G1 CS eee ee ee ee et [Ed ee CO eee Be) Pet 4.6 
Middle Atlantic Continental Shelf 4_|_____ dol sete 2 ae 61.9 
Humboldt Current, Peru ®_________ Anchovy=o2..20-22- 300 
Chesapeake Bay 5 oyster bottom____| Oyster_____________ 600 
Sea water, fertilized: 2 
Fishponds, Formosa___________---_- IMO Stas a 1, 000 
Brackish water, fertilized: 
Experimental fish farm, Palestine___| Carp_--_-_-_-----_- 755-7, 970 
Commercial ponds, Palestine_-_---__|---_-- doe fees eee 356-4, 210 
Land: 
Cultivated land__............--- SWIG sae. Sone 450 
Grneniand 2 052.652 eee es Cattle sate = ee se 5-250 
1 Data unless otherwise indicated from C. H. Mortimer and C. F. Hickling, ‘‘Fertilizers in Fishponds.”’ 
Fishery Pub. No. 5, 1957. London: Her Majesty’s Stationery Office. 
2 Ponds constructed so that sea water can enter through gates. Gates can be closed to contain fish. 
3C. L. Cutting. Economic aspects of utilization of fish. Biochemical Society Symposium No. 6. Bio- 
chemical Society. Cambridge, England. 
4 Range of values for selected ocean areas listed by H. W. Graham and R. L. Edwards. 1961. Fish in 
nutrition. 
5J. L. McHugh. In press. In Symposium on Estuaries. American Association for Advancement of 
Science. 
6M. B. Schaefer. 1965. Transactions American Fisheries Society. Vol. 94, pp. 123-128. 
is informative to make some calculations concerning potential oyster 
production in these areas. If 600 pounds were produced per acre, 
the yield in Japan and in Chesapeake Bay under natural conditions, 
then the total U.S. production would be 6 billion pounds annually 
or about equal to the present U.S. fish catch (table 2.2). If the pro- 
duction rate in these areas were increased 15 times, the yield would 
be 90 billion pounds a year or nearly equal the present world fish catch. 
A 15-fold increase does not seem unrealistic since the Japanese have 
increased yields as much as 50-fold. The yield of oysters is appar- 
ently limited by their food supply. If production of suitable kinds 
of phytoplankton could be increased by artificial fertilization (see 
13 
