42 
PACIFIC SCIENCE, Vol. XIII, January 1959 
Figs. 13, 14. Series 2, Stations 159-192, January 29-February 1, 1951. The distribution of the four planktonic 
groups in relation to Figure 13, Temperature, °C.; and Figure 14, Salinity, °/oo- S.S.A. (Southern Subantarctic 
group); N.S.A. (Northern Subantarctic group); S.T, (Subtropical group); C. (Coastal group). Temperatures or 
salinities additional to those taken at plankton stations • ; plankton station numbers are underlined. 
When compared with Series 3, higher tem- 
peratures near the coast of South Island (Fig. 
17) point to a restoration of the influence of 
mixed coastal-subtropical waters, originating 
probably in the west. A slight influence from 
water of subantarctic origin is indicated by 
the shoreward deflections of isotherms south 
of Nugget Point. The pronounced shoreward 
bulges of isotherms and isohalines at a num- 
ber of other localities are suggestive of 
stronger influences from the same source 
(Figs. 17, 18). The conformation of these 
isolines may suggest as well an offshore 
movement of coastal water in adjacent areas. 
Steep temperature gradients between the 
warm saline coastal and the cool, less saline 
oceanic waters are suggestive of mixing, over 
short distances. There is an area of more 
general mixing extending from shortly south, 
to north, of Dunedin. 
In the T-S diagram (Fig. 3) the plankton 
stations of Series 4 lie in a group between 
11.75° and 14.5°C., and (all but Station 239), 
between 34.3 and 34.4 / oo salinity. Thus they 
are closely associated with Stations 212, 214, 
etc., of Series 3. At each of Stations 270, 285, 
297, 301, and 308 there is a strong representa- 
tion of Northern and Southern Subantarctic 
planktonic groups (Fig. 10). Therefore, the 
position of the stations in the T-S diagram, 
and their plankton content, associate them 
with the water of subantarctic origin. The 
