84 



Fishery Bulletin 100(1) 



— 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 IE 

 Age (yr) 



-Fishery-Independent — »— Headboat -h- Commercial 



Figure 2 



Mean back-calculated length at age of red porgy 

 obtained from a fishery-independent source ( MAR- 

 MAPl, headboat operations, and commercial fish- 

 ery operations between 1996 and 1998. 



The weight-length relationship for red porgy in the 

 southeastern United States was best described by the con- 

 verted In-ln regression equation of IV = 8.85 x 10^''(L)''^"' 

 (r-=0.96, /!=230, MSE=0.01l. 



Age-length keys by sample source are presented in 

 Table 2. The fishery-independent key is appropriate for 

 fishery-independent length data only The headboat and 

 commercial keys can be used to convert unaged length sam- 



ples of red porgy from the fisheries operating in the south- 

 eastern United States to aged ones. Annual keys were not 

 available owing to the small sample size from each year. 



Discussion 



In two previous aging studies on red porgy from the south- 

 eastern United States, populations were examined at two 

 different levels of exploitation and different structures 

 were used to determine age. Manooch and Huntsman 

 (1977) sampled recreationally caught fish from an almost 

 virgin stock off North Carolina and South Carolina during 

 1972-74. Although they used scales and whole otoliths, 

 the main focus of their study and the analysis were on 

 ages determined from scales. Of the 3278 scales analyzed, 

 only 54'^'f (1901) were legible enough to record ages. The 

 main problem of aging red porgy with scales was the 

 large number of regenerated scales." Harris and McGov- 

 ern (1997) used whole otoliths (?7=4281) to age fish col- 

 lected between 1979 and 1981 and between 1988 and 1994 

 from the MARMAP survey, a fishery-independent source. 

 The 1988-94 samples in their study came from the area 

 off North Carolina through northeast Florida, although 

 73% were collected in the area off Charleston, SC, between 

 32°N and 33°N. The samples were limited mainly to indi- 

 viduals below 450 mm TL (less than l'~f of samples were 



Manooch. C. S. 1998. Personal conimun. NOAA. Center for 

 Coastal Fisheries and Habitat Research. 101 Fivers Island 

 Road, Beaufort, NO 28516. 



