34 



Papers from the Department of Marine Biology. 



oxygen scale at left of figure 5 for temperate and tropical seas) . The 

 scale at the extreme left shows that the temperature is raised only 0.04° 

 by animal respiration that uses up all of the oxygen in the warmer 

 seas. This shows the impossibihty of the existence of a warm-blooded 

 animal with gill respiration. 



The oxygen-content of sea- water may be estimated from the Ph, 

 since the differences between cubic centimeters of CO2 and O2 in 2 

 samples of water of the same excess base are reciprocal. 



The change in Ph with change in CO2 tension is affected only by the 

 temperature, as shown in conversion table in figure 6. 



•5 3 



1 « 



FiQ. 5. — Conversion table for determining the total CO2 and O2. and the rise in temperature of 

 sea-water due to the respiration of marine animals, from the excess base andPn- The three 

 diagonals are for three values of the excess base. On the abscissa is given the Pg and on the 

 ordinate are four scales, one for the total CO2, one for the approximate O2 of tropical oceans, 

 one for the O2 of temperate oceans of about 20°, and one for the approximate rise in tempera- 

 ture due to respiration of marine animals, in hundredths of a degree. This estimate of rise in 

 temperature is a little too small, but can not be calculated exactly. 



Changes in salinity theoretically affect the CO2 tension and hence 

 CO2 content of sea-water. Fox divides the CO2 into two parts, one of 

 which obeys Henry's law and never exceeds 1 per cent of the total. 

 It is this small fraction that is affected by salinity, but the changes in 

 salinity ordinarily met with in the larger oceans change this fraction 

 only about 1.5 per cent, and the total change is exceedingly small. 

 We have not been able to determine any effect of salinity on Ph or CO2 

 content. 



