674 



Fishery Bulletin 97(3), 1999 



20 



15 



10 



_ 5 



-86 — Yearly landings 



— ^ Average landings. 1985-93 



Canadian landings 



1 - 



Figure 9 



Monthly haddock landings in 5Zj,m from 1985 to 1993. 



most variable.The net migration rate towards the U.S. 

 side from October to March was often lowest at age 1, 

 intermediate at ages 2 and 3, and gi-eatest at ages 4 

 and older. By ages 4+ net migration back and forth 

 seemed to be balanced. This general pattern was sup- 

 ported by the migration rates for the entire period ex- 

 amined, but the trend was less distinct from April 1985 

 to October 1987 than from April 1988 to October 1993. 

 Examination of the spring ratios of relative abundance 

 showed very high values during 1985-87 for ages 4-8 

 haddock (Fig. 8l, indicating that there was not much 

 movement across the ICJ line during that period. 



Figure 11, which shows the movement and remov- 

 als of a weak and a strong year class, the 1984 and 



1985, respectively, for ages 1 and older, illustrates 

 the migratory nature of the 5Zj,m stock across the 

 ICJ line. The migratory pattern is well illustrated; a 

 portion of the stock moved to the U.S. side from Oc- 

 tober to March and most of the stock moved back to 

 the Canadian side from April to September. In spring 

 the abundance on the Canadian side remained higher 

 than on the U.S. side. The U.S. catch often consisted 

 primarily offish that had moved across the ICJ line 

 from the Canadian side to the U.S. side and is indi- 

 cated in the figure by the arrows pointing to the left. 

 No obvious pattern between net migi-ation rates and 

 population abundance was found. The range of abun- 

 dance, however, for this period was very limited. 



