Zooplankton — Bary 
41 
at Stations 189 aod 190, but at the same time 
demonstrates an overall influence from Sub- 
antarctic species which are being introduced 
by water of subantarctic origin. 
Subantarctic species, and water of subant- 
arctic origin, are more in evidence at stations 
of Series 2 than at those of Series 1 (for which 
Subtropical species indicate that at least some 
of the water has originated in the subtropical 
mass). The differences between the series are 
concisely illustrated by the T-S-P diagrams 
(Figs. 7, 8, 10). 
Series 3. Smions 193 to 228; 3 to 13JIJ1 
The beginning of Series 3 is separated by 
four days from the end of Series 2. In Series 2, 
lower temperatures than in Series 1 pointed to 
an increased subantarctic influence off the 
coast of South Island. In Series 3, cool, low- 
salinity water has intruded strongly towards 
the coast, centred a little to the west of Sta- 
tions 216 and 218 (Figs. 15, 16). This intru- 
sion appears to be acting as a barrier to an 
east-going coastwise movement of warm, 
high-salinity water, causing it to spread in a 
fanlike manner towards the southeast. High 
salinities and temperatures to the east of 
Stewart Island suggest that some of this water 
may be escaping in a narrow zone along the 
coast of the island. The isohalines and, to a 
lesser extent, the isotherms indicate that the 
influence of the cool, low-salinity water ex- 
tends well in towards the Strait. 
Apart from an exceptional occurrence of a 
Coastal species at Station 212, the plankton 
taken at Stations 210, 212, 214, 216, 218, and 
206 is entirely of Southern and Northern 
Subantarctic groups (Figs. 10, 5, 6, 7). The 
water at these stations, therefore, is regarded 
as being of subantarctic origin. The stations 
are moderately separated geographically (Figs. 
1, 15). However, their aggregation in the T-S 
and T-S-P diagrams (Figs. 3, 10) emphasises 
an essential homogeneity of the water which 
the occurrences of the subantarctic species 
confirm. 
Four stations, namely 218, 208, 198, and 
199 are located in water of slightly higher 
salinity (Fig. 10) than the other stations of the 
Series, possibly as the result of coastal water 
mixing with that from the subantarctic. Oc- 
currences of Coastal plankton at 208 and 198 
support this view; the subantarctic influence 
is evident from the Southern Subantarctic 
species captured at 218 and 198, and Northern 
and Southern Subantarctic species at 208. (No 
selected species were taken at Station 199.) 
From the geographic charts Station 218 ap- 
pears from its temperature (Fig. 15) to be in- 
fluenced by subantarctic water; on the other 
hand, the comparatively high salinity sug- 
gests some influence from coastal-subtropical 
water. As Southern Subantarctic species only 
were taken, the latter influence was not con- 
firmed by the plankton haul. The temperature 
and salinity at Station 208 indicate that it is 
located in mixed waters and its plankton 
content supports this. 
It is of interest that the distribution of the 
selected Subantarctic species of Series 3 indi- 
cates that uncontaminated water of subant- 
arctic origin has a restricted salinity range of 
between about 34.2 and 34.45 / oo (Figs. 
3 , 10 ). 
There are distinctive characteristics to the 
species composition of stations in this, as 
compared with the previous two series, which 
are readily seen from the T-S-P diagrams. 
They are believed to be directly attributable to 
the different properties which are evident be- 
tween the waters of the three series. Unlike 
Series 1 and 2, water of subantarctic origin is 
dominant in Series 3, and the occurrences of 
the Subantarctic species coincide with and, in 
fact, delineate its extent in the diagrams 
(Figs. 5, 6, 7, 10). 
Series 4. Stations 229 to 314; 8 to 9-111.3 1 
The collections of this, and the subsequent, 
series are as nearly synoptic as is possible from 
a single ship. Stations of Series 4 were occu- 
pied approximately one month later than 
those of Series 3. 
