Creaser and Perkins: Distribution, food, and abundance of Pomatomus saltatrix 



505 



Marsh River 1990 

 N = 120 



Marsh River 1991 

 N = 56 



£ 



Z 



35 45 55 65 75 85 95 105 115 125 135 145 155 165 



Julian Date Of First Ring Deposition 



Sagadahoc Bay 1990 

 N = 29 



35 45 55 65 75 85 95 105 115 125 135 145 155 165 



Julian Date Of First Ring Deposition 



Mere Point 1991 

 N = 31 



5 



a 



£ 



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35 45 55 65 75 85 95 105 115 125 135 145 155 165 



Julian Date Of First Ring Deposition 



35 45 55 65 75 B5 95 105 115 125 135 145 155 165 



Julian Date Of First Ring Deposition 



Figure 3 



Estimated dates of ring deposition in otoliths of juvenile bluefish, Pomatomas saltatrix, collected in Maine: (A) 

 Marsh River 1990; (B) Marsh River 1991; (C) Sagadahoc Bay 1990; and (D) Merepoint Bay 1991. 



All Areas Combined 

 1990 N = 149 1991 N 



1991 



Figure 4 



The relationship between log 10 fork length (X) and 

 the number of daily rings (Y) for juvenile bluefish, 

 Pomatomas saltatrix, captured in Maine during 

 1990-91. The regression equations are Y = -209.891 

 + 162.6751 log 10 X, fl 2 =0.834, for 1990 and Y= 

 -151.461 + 132.0466 log 10 X, R 2 = 0.629, for 1991. 



lengths recorded during 1991 (93-200 mm) was small 

 compared with 1990 (37-197 mm). The number of 

 daily growth rings varied between 58 and 200 ( 1990 ) 

 and between 97 and 176 (1991). Although an 

 ANCOVA revealed that the slopes of the relation- 

 ship of log 10 fork length to number of daily rings dif- 

 fered significantly between years (P<0.05), the sig- 

 nificance of this is questionable because the size 

 range offish also differed between years. Nyman and 

 Conover (1988) analyzed similar regressions for ju- 

 venile bluefish captured in New York waters during 

 1985 and 1986 and found significant differences in 

 slopes between years. Individual values for fork 

 lengths and daily ring counts collected in New York 

 waters during 1985-1986 obtained from Robert 

 Nyman 4 were fit to quadratic equations and com- 

 pared to similar values obtained in Maine during 

 1990-91 (Fig. 5). Fork lengths varied between 41 and 

 166 mm ( 1985) and between 31 and 167 mm ( 1986). 



Nyman, R. U.S. Environmental Protection Agency, 401 M St., 

 SW, Washington, DC 20460. Personal commun., June 1991. 



