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PACIFIC SCIENCE, Vol. VII, July, 1953 
Fig. 10. Comparison of rainfall and chlorinity curves for a 2-year period from February, 1949, to February, 
1951. Chlorinity of surface waters is indicated by broken lines, of bottom waters by solid lines. 
In the sampling at intervals, at first both 
surface and bottom temperatures were taken 
weekly at all the stations where the depth of 
the water permitted, and bottom temperatures 
were taken at those stations where the water 
was too shallow to obtain differential samples 
with the modified oxygen sampler. As it was 
soon found that there was no great tempera- 
ture differential between top and bottom at 
the shallow stations, 5, 6, 7, and 11, only 
one temperature was later taken at these sta- 
tions, and as stations 4 and 6 were like stations 
3 and 5, respectively, temperatures were taken 
monthly at stations 4 and 6. After March, 
1950, temperatures were taken monthly at all 
stations. 
Water temperatures were taken by means 
of a thermometer graduated in 1°C divisions 
and attached to the modified oxygen sampler. 
Temperatures were estimated to the closest 
0.1 °C and were graphed to show seasonal 
variations (Fig. 11), averages being used when 
the differential between top and bottom was 
less than 0.5°C. As expected, there was a close 
agreement of changes from station to station. 
and all stations showed a definite seasonal 
change. Deeper stations 1 and 2 showed the 
most gradual seasonal changes, and station 
10, the very shallow station on the flats, 
showed the greatest extremes of temperature 
with a range from 20.5 to 33.3°C. 
The extreme alternation between high and 
low temperatures on successive weeks, most 
noticeable in March and April, 1949, at sta- 
tion 10, was characteristic of the shallower 
stations and was the result of tidal differences. 
One week, at the time of sampling, the tide 
would be very low, while on the following 
week at the same hour it would be high. In 
weeks when the tide was low, the shallow 
waters were warmed and were not mixed with 
the cooler deep waters until the next flooding 
tide. In the following week when the tide 
was high at the same hour, the warmed waters 
were mixed with the cooler water brought in 
from the deeper channels. 
Under normal conditions the surface waters 
tended to be warmer than bottom waters be- 
cause of the warming effects of the sun and 
the decreased density of warmer water. How- 
