538 



Fishery Bulletin 91(3). 1993 



1986 



n = 418 



1989 



n = 302 



JUuJk, 



10 20 30 40 50 60 70 80 90 

 LENGTH (cm) 

 Figure 1 



North Carolina Division of Marine Fisheries (NCDMFl 

 1986-1989 bluefish iPomatomus saltatrix) length-age test 

 data: percent at length distributions by year. 



cohort of the previous calendar year. Depending on the 

 exact time of spawning and sampling, the largest age- 

 fish may be 12-15 months old, while the smaller 

 age-0 fish are about 10 months old. Under the birthdate 

 convention of 1 January used by NEFSC fisheries bi- 

 ologists, all of these fish would be classified as age 

 class 1. This difference in classification schemes has 

 caused confusion in previous stock assessments and 

 other research for bluefish. The NCDMF length-age 

 test data in this paper are based on the 1 June 

 birthdate convention. 



Connecticut, New Hampshire, North Carolina (CNN) 

 length-age data Length-age sample data (/? = 3883, 



12-87 cm, ages to 11, ages determined from scale 

 annuli) were available for bluefish collected by state 

 agencies in Connecticut (1984-1985, n = 1452), New 

 Hampshire ( 1986, n = 76), and North Carolina (1982- 

 1985, n = 2355) (Fig. 2). The 1 June birthdate conven- 

 tion was employed in aging. Connecticut and New 

 Hampshire fish were collected in research surveys, 

 mainly during the summer and fall when most recre- 

 ational fishing occurs (June-October). North Carolina 

 fish were taken throughout the year in proportion to 

 the number of fish landed by commercial fisheries. 

 These data were combined to form a matrix of the 

 distribution of age at length for bluefish. This matrix 

 was applied as a standard age-length key (CNN ALK) 

 to the NCMDF 1986-1989 annual length distributions 



30 40 50 60 70 

 LENGTH (cm) 



80 90 



40 



e- 30 - 



20 - 



10 



1234567891011 



Figure 2 



Connecticut, New Hampshire, and North Carolina length- 

 age data (n=3,883l for bluefish (Pomotomus saltatrix) used as 

 the basis for the Connecticut, New Hampshire, and North 

 Carolina age-length key (CNN ALKl and the interated age- 

 length key (IALK) method. 



