360 



Fishery Bulletin 100(2) 



•a I 



S' 0.8 



0) 



g 





^S'ff'^^5\^a-^ 



Figure 2 



Annual mean weight of red porgy off the southeastern 

 United States in landings from commercial hook-and- 

 line. headboats from the Carolinas, and from all fisheries. 

 Minimum size limit was introduced in 1992. 



what, and fjradually increased through the present (Fig. 

 4Ai. Of the two matrices, the primary matrix provided 

 lower estimates of full F in the recent period, particularly 

 with zeroes replaced by missing values. 



Estimates of recruitment were not particularly sensi- 

 tive to estimation procedure. A general decline in recruit- 

 ment, 1973-97, was estimated from both catch matrices 

 and with either treatment of zeroes (Fig. 4B). 



Sensitivity runs on the primary catch matrix, but with M = 

 0.20/yr or M = 0.35/yi", estimated that patterns in F and re- 

 cruitment were similar to those with the base value of M = 

 O.'28/yr (Fig. 5). Under the assumption M = 0.20/yr, esti- 

 mated values of F were higher than the base assessment; 

 whereas under the assumption M = 0.35/yr, estimated val- 

 ues of F were lower (Fig. 5A). Effect of the value of M on 

 recruitment increased with each year backwards in time. 

 Regardless of the value of A/, the pattern of estimates was 

 of initially high recruitment, followed by a long period of 

 severe decline (Fig. 5B). 



For comparative purposes, VPA fits were also made by 

 using only the hook-and-line index or only the extended 

 chevron-trap index. Essentially no differences were noted 

 in estimates of full F or recruitment to age 1. 



In our VPAs, we estimated statistical weights for the two 

 calibration indices. Estimated weights varied only slightly 



