530 
PACIFIC SCIENCE, Vol. XV, October 1961 
NUMBER TIMES SUBMERGED (1953) 
5 10 15 20 
NUMBER TIMES SUBMERGED (%) 
FIG. 45. Diagram showing number (and per cent) 
of times tidal condition caused submergence of vari- 
ous regions in the intertidal zone. 
(Kjellm. and Setch.) f. valida, Constantinea sim- 
plex Setch., and H alio tis kamtschatkana Jones. 
Isolated populations of the abalone ( Haliotis 
kamtchatkana) , which have been noted farther 
eastward in Johnstone Strait and which may 
be related to local oceanographic features, pre- 
sent something of an anomaly in the general 
distribution. An exception to the general dis- 
tribution described in this group is that of 
Macrocystis integrifolia. Although Macrocystis 
occurs in regions of high salinity and extends 
as far down the Strait as the north side of Mal- 
colm I. and the south side of Numas I., it does 
not occur in the most exposed areas where 
Postelsia and Mitella are encountered. 
Vertical Distribution of Organisms 
The vertical distributions with reference to 
tide levels, based on data obtained using an 
Abney level, are presented for some of the more 
conspicuous organisms at Hope I. (Fig. 50). 
Comparisons are made also for some of these 
(Fig. 51) at Hope L, Deer L, and near the 
Klucksiwi River, to indicate the effect exposure 
to surf has on the vertical distribution of some 
organisms. 
By comparing the vertical distributions of 
organisms in Queen Charlotte Strait (Fig. 50) 
with tidal data presented with respect to emer- 
gence and submergence (Figs. 42-45), a num- 
ber of limiting levels are fairly apparent. Near 
the top of the intertidal zone is a region 
(HHHW to HLHW) which is rarely submerged 
(Fig. 43) for more than a few hours on each of 
a few days at any period of the year and which 
OXYGEN (mg/L.) 
FIG. 46. Distribution of oxygen with depth at vari- 
ous stations in Queen Charlotte Strait and adjacent 
regions in June, 1953. 
