400 



BULLETIN OF THE BUREAU OF FISHERIES 



augmented similarly in volume at the mouth of Massachusetts BayCfrorn less than 

 5 cubic centimeters on March 1 (station 20050) to at least 200 cubic centimeters on 

 April 9 (station 20090), while Fritz (1921) records the numbers of diatoms per haul 



Portland 



Fig. 108.— Volumes of phytoplankton (in cubic centimeters) per standard surface haul in February and March, 1920. The 

 hatched curve incloses areas with more than 50 cubic centimeters; the stippled curve with more than 250 cubic centi- 

 meters 



as increasing from about 28,000 on March 15 to upwards of 9,000,000 on May 1 at 

 St. Andrews. 32 When the water is cloudy with diatoms, as is the usual state when 



s * Fritz's counts are for the catches of horizontal hauls that fished through an unmeasured volume of water. 



