PLANKTON IN NITROGEN AND PHOSPHORUS CYCLES
175
variation of temperature and salinity with depth below 50 m altered
during the intervening period and it was therefore necessary to compare
changes in concentrations at isopycnal surfaces (i.e. where the water
had the same density on the two occasions) for which salinity and
A
E
C
D
E
F
C
H
A
E
C
D
E
F
C
H
July 1957
0
100
200
A
B
C
D
E
F
G
n
J
Stations
Fro. 9B. The seasonal variation of phosphate-phosphorus off the coast of New England.
Details aa for Fig. 9A. (After Ketahum el d., 1958.)
175
variation of temperature and salinity with depth below 50 m altered
during the intervening period and it was therefore necessary to compare
changes in concentrations at isopycnal surfaces (i.e. where the water
had the same density on the two occasions) for which salinity and
A
E
C
D
E
F
C
H
A
E
C
D
E
F
C
H
July 1957
0
100
200
A
B
C
D
E
F
G
n
J
Stations
Fro. 9B. The seasonal variation of phosphate-phosphorus off the coast of New England.
Details aa for Fig. 9A. (After Ketahum el d., 1958.)