36 
PACIFIC SCIENCE, VoL XIII, January 1959 
aggregation (except Station 125), suggesting 
little or no influence from water of sub- 
tropical origin. A third group of stations 
yielded comparatively small mixed catches of 
Coastal, Subtropical, and '"Tolerant” Southern 
Subantarctic species, which indicates that 
mixing was also taking place. This mixing 
may have been on a minor scale or the small 
catches may be due to the tows being made in 
daylight. The stations form a discontinuous 
series extending more or less vertically 
through the diagram to terminate at Stations 
130 and 138. 
The distributions of the groups in Figure 
10 are brought about by movements of the 
waters of which they are indicators. There- 
fore, the general courses of such movements 
should be traceable from these distributions. 
The fact that subtropical oceanic species are 
present in the coastal water indicates that 
water of subtropical origin is moving into the 
coastal water. Similarly the distribution of the 
Subantarctic species shows they also are being 
carried into the coastal water. These move- 
ments are shown by stippled arrows in Figure 
10. Those portions of the T-S-P diagram 
which are illustrative of intensive mixing of 
plankton and waters suggest that, as well as 
these general movements, there are others in 
which there is a more vigorous, localised 
penetration shorewards. It would seem that 
these are predominantly of water of subant- 
arctic origin, intruding into coastal water. 
A number of the stations of each of the 
regions of mixed waters in Figure 10 are wide- 
ly distributed geographically and in time. 
Nevertheless, where similar environmental 
properties have ensued on the mixing of the 
waters, the group composition of the plank- 
ton hauls, and often the quantity collected, 
are comparable. Thus in this T-S-P diagram, 
the selected representatives of the zooplank- 
ton emphasise and enable the identification of 
those stations at which mixing of waters is 
inducing similarities in the environmental 
conditions. Conversely, the diagram shows 
for those stations at which one group of spe- 
cies is present, or predominates, that the 
water is entirely or predominantly of that 
mass for which the species constitute an 
indicator group. 
It can be argued with respect to the "faunal 
island” about Stations 322 and 326 (Fig. 10) 
that more frequent sampling would have re- 
vealed a continuity in the species distribution 
between these and other stations of the series 
(Fig, 2). In all, seven salinity-temperature and 
plankton stations were occupied near to and 
north of what is believed to be the subtropical 
convergence (Figs. 4^, 19^), and all are lo- 
cated in the T-S diagram (Fig. 3) in water of 
subtropical origin. 
Waters of mixed properties undoubtedly 
occur about the convergence. liowever, 
should water of either subtropical or subant- 
arctic origin be present in slightly greater 
quantity, stations would tend to aggregate in 
the one or the other in the T-S diagram. The 
predominating water would be reflected in 
the species which were present. On the other 
hand, if samples are from truly intermediate 
conditions, an intermediate position would be 
occupied in the diagrams; but if the transition 
zone is narrow (as in the present traverse, see 
Fig. 4^), such samples would be rare. The 
subtropical group of species predominated at 
Stations 322 and 326, which agrees with the 
stations being north of the convergence and 
in water largely of subtropical origin (some 
Subantarctic species were taken, but they are 
believed to have originated in the subsurface 
subantarctic water, seep. 47). In the circum- 
stances, therefore, it seems reasonable to sepa- 
rate Stations 322 and 326 from the remainder. 
GEOGRAPHICAL DISTRIBUTIONS OF TEMPERA- 
TURES, SALINITIES, AND SELECTED SPECIES, 
AND CORRELATION OF THESE WITH THEIR 
DISTRIBUTIONS IN T-S-P DIAGRAMS 
A sequence of geographical charts incorpo- 
rating synoptic or quasi-synoptic collections 
of temperatures and salinities should demon- 
strate cyclical or other changes in the distri- 
