FISHERY BULLETIN: VOL. 79, NO. 1 



E 

 E 



X 



h- 



LJ 



60 p 



55 

 50 

 45 

 40 

 35 

 30 

 25 

 20 



15 

 10 



N = 90 



A 



a 



X 



24 OCT (4) 

 8 NOV (29) 



29 NOV (4) 

 19 DEC (14) 

 10 JAN (2) 



30 JAN (6) 

 6 MAR (31) 



Y« 10.59 + 0.29X 



Y= -7.42 +0.36 X 



I I I 



J L 



J L 



-I L 



I I I I 1 L 



45 



40 



35 



30 



25 



-20 



E 

 E 



LU 



10 20 30 40 50 60 70 80 90 100 1 10 120 130 140 150 160 170 180 



NUMBER OF OTOLITH GROWTH INCREMENTS 



190 



Figure 6. — Growth of the first group of Atlantic herring larvae which entered the Sheepscot River estuary, 

 1978-79. This includes all larvae from the towed net samples in which the first otolith daily growth increment was 

 formed before 30 October. The plotted symbols indicate the collection date and the numbers in parentheses 

 indicate sample size. Regression lines were calculated for the samples collected before and after the winter period 

 of interrupted growth and the 30 January samples were therefore not included. 



The growth rates of Atlantic herring larvae in 

 the Sheepscot estuary as determined using daily 

 growth increments in the otoliths were about 2 

 mm/wk, excluding the winter period of retarded 

 growth. The growth rate of group 2 larvae, how- 

 ever, was lower after this period. Our estimates 

 of larval growth rates, excluding the retarded 

 growth period, are comparable with autumn and 

 spring values reported by other workers (Table 

 1). Rosenberg and Lough (footnote 4) used daily 

 growth increments in the otoliths to study the 

 growth of Georges Bank herring larvae. The lar- 

 vae were from a short sampling period (1-18 Octo- 

 ber 1976), but the authors estimated the growth 

 rate to be about 2.4 mm/wk. This October growth 



Table L — Published growth rate estimates for fall spawned 

 Atlantic herring larvae in the northwest Atlantic. 



rate estimate is greater than our fall and spring 

 estimates, possibly the result of different water 

 temperatures. The relatively wide range in esti- 



128 



