Population structure and mortality of Micropogonias furnieri, Macrodon ancylodon and Cynoscion jamaicensis, off southeastern Brazil, from 1982 to 1996

Abstract

The numbers of individuals, the biomasses and the fishing mortalities, in each age class for the populations of whitemouth croaker, Micropogonias furnieri, king weakfish, Macrodon ancylodon, and jamaica weakfish, Cynoscion jamaicensis, living between 23°S and 29°S, during the period from 1982 to 1996, were estimated. Results show, for whitemouth croaker, recruitment ranging from 40,000,000 to 90,000,000 recruits, with an average of 54,260,000 recruits, and biomass ranging from 6,450 ton to 11,000 ton and an average of 8,248 ton. The estimates for the catchability coefficient ranged from 3.68 x 10^-5 to 8.41x10^-5, averaging 5.45 x 10^-5. For king weakfish, results show recruitment ranging from 20,000,000 to 60,287,000 recruits, averaging 31,600,000 recruits, and biomass ranging from 2,422 ton to 5,427 ton, with average of 3,572 ton. The estimates of the catchability coefficient ranged from 3.77 x 10^-5 to 8.47 x 10^-5, averaging 5.86 x 10^-5. For Jamaica weakfish, results show recruitment ranging from 100,000,000 to 800,000,000 recruits, with an average of 351,212,000 recruits, and biomass ranging from 8,748 ton to 17,858 ton, with an average of 11,638 ton. The estimates for the catchability coefficient ranged from 5.0 x 10^-5 to 21.7 x 10^-5, and averaged 9.95 x 10^-5.