FISHERY BULLETIN; VOL. 75, NO. 4 



TABLE 5. — Average annual catch of shrimp (in pounds, heads-off weight) per vessel 

 by country. Data are derived from Tables 3 and 4. 



and 1962, respectively, but for 1963-74 they 

 ranged from 3% to 18%, averaging 8.5%. These 

 variations in catches are deviations about the 

 mean condition predicted by the model. The devia- 

 tions include the effects of dynamic environmental 

 conditions, but also include random variations 

 and the failure of the model to predict the effects of 

 fishing. 



The Penaeus shrimp fishery operates mostly on 

 a single year class and year-to-year fluctuations in 

 shrimp populations are to be expected because of 

 the short life cycle of the species. Fluctuations in 

 the annual yield of shrimp are partly the result of 

 variations in spawning success and in survival of 

 young in the inshore nursery grounds, which are 

 generally subject to more extreme variations in 

 environmental conditions than the offshore 

 habitat of adult shrimp. An important manage- 

 ment problem for this shrimp fishery is to predict 

 and utilize annual fluctuations in the populations, 

 rather than to only predict an equilibrium yield at 

 a constant level of fishing effort. This will require 

 more detailed knowledge of growth, mortality, 

 and recruitment patterns of the shrimp and the 

 application of yield-per-recruit and stock-re- 

 cruitment models. 



LITERATURE CITED 



ALLEN, H. B. 



1973. U.S. -Brazil shrimp conservation agreement — A 

 status report. Proc. Gulf Caribb. Fish. Inst. 25:23-25. 



BULLIS, H. R., JR., AND J. R. THOMPSON. 



1959. Shrimp exploration by the M/V Oregon along the 

 northeast coast of South America. Commer. Fish. Rev. 

 21(11):1-19. 



Cook, H. L., and M. J. Lindner. 



1970. Synopsis of biological data on the brown shrimp 

 Penaeus aztecus aztecus Ives, 1891. FAO Fish. Rep. 

 57:1471-1497. 

 COSTELLO, T. J., AND D. M. ALLEN. 



1970. Synopsis of biological data on the pink shrimp 

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 FOX, W. W., JR. 



1970. An exponential surplus-yield model for optimizing 

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 80-88. 

 HIGMAN, J. B. 



1959. Surinam fishery explorations, May 11-July 31, 

 1957. Commer. Fish. Rev. 21(9):8-15. 

 JONES, A. C, AND A. DRAGOVICH. 



1973. Investigations and management of the Guianas 

 shrimp fishery under the U.S.-Brazil Agreement. Proc. 

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 NAIDU, K. S., AND L. K. BOEREMA. 



1972. The high-sea shrimp resources off the Guyanas and 

 northern Brazil. FAO Fish. Circ. 141, 18 p. 



Perez Farfante, I. 



In press. FAO species identification sheets for fishery pur- 

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 31). Food and Agriculture Organization of the United 

 Nations, Rome. 

 ROUNSEFELL, G. A., AND W. H. EVERHART. 



1953. Fishery science: its methods and applications. 

 John Wiley and Sons, Inc., N.Y., 444 p. 

 WHITELEATHER, R. T., AND H. H. BROWN. 



1945. An experimental fishery survey in Trinidad, Tobago 

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