Begg et al.: Use of otolith morphometries for identification of stocks of Melanogrammus aeglefinus 
11 
2 . 0-1 
0.5 - 
O 
a. _-| 0 
-2.5 
Age group 1 , year class 1 994 
(PC I, P< 0.0572) 
■ 
■ ■ 
3.0 1 
2 1 . 0 - 
o 
- 1.0 
-3.0 
Age group 3, year class 1994 
(PC I, P< 0.0060) 
o 
o ° ® 
° °° 
oo ° o° 
%° °& a5 o 
0„ u n O' 
-4.0 -2.0 
0.0 
2.0 
-2.5 -0.5 
1.5 3.5 
3.0 
1.0 
O 
^ - 1.0 
-3.0 
Age group 2, year class 1995 
(PC II, P<0.0096) 
Qd 
_ o 
O o o 
£ ■ 
-2.5 -0.5 
1.5 3.5 
3.0 1 
2 ) 1.0 
o 
o 
O 
-1.0H 
-3.0 
Age group 4, year class 1993 
(PC II, P<0.1 572) 
o K* 
o o 
o 
-3.5 
-1.5 
0.5 
2.5 
Age group 3, year class 1993 
3.0 i (PC III, P<0. 0467) 
2 1.0 
o 
O 
Q- -1.0 
-3.0 
-2.5 -0.5 
1.5 
3.5 
3.0-1 
9 ) 1 . 0 - 
O 
°- - 1.0 
-3.0 
Age group 5, year class 1992 
(PC II, P<0 0011) 
i - 
-2.0 -0.5 
1.0 
2.5 
PC I score 
Figure 7 
Principal component (PC) analysis of internal otolith morphometric variables and ANOVA results showing 
grouping patterns of eastern Georges Bank (squares) and western Georges Bank (circles) haddock. 
management units that are consistent and account for the 
underlying stock structure of the resource. An incorrect 
decision could lead to significant shifts in resource dis- 
tribution, changes in stock productivity, or declines in re- 
cruitment across stock unit boundaries. Although the pre- 
cautionary approach would imply that we accept the two 
stock hypothesis as the default scenario until proven oth- 
erwise, this has not been the case. It would be desirable 
to ensure the conservation and stock rebuilding potential 
of both spawning components, particularly because we do 
not know at present the relative contribution of each to the 
overall status of haddock on Georges Bank. 
