Doubtless the prominence of blue-greens in this section is due, 

 in part at least, to pollution. This group is particul£.rly favored 

 by the presence of an abundance of nutrient material, and commonly 

 thrives in polluted vraters. 



Maumee Bay Section 



Three regular stations were located in this section: Station 250, 

 at the mouth of Maumee River; Station 252, at Toledo Harbor range lights; 

 and Station 25ii, at Toledo Harbor Lighthouse (see Fig. 1) . This area 

 was not studied for as long periods as the Island Sec;tion, and as a 

 result, very little was learned of the seasonal distribution of the 

 plankton algae. The available data for the seasons of 1929 and 1930 

 are given in Tables 56, 57 and 53. 



Station 250 . The depth at Station 250 was three meters in 1929, 

 and, as a result of dredging, about six meters in 1930. However, the 

 depth of the general area is less than two meters. At this station 

 the physical and chemical conditions are unusually subject to change 

 because the current of the river reverses periodically. Sometimes 

 the water here is river vrater and at other times it is water from the 

 bay. Only four samples in as many months were taken in 1929 (Table 56) • 

 Little can be gained from these few records, but it should be pointed 

 out that the counts were not unusually large except on September 7, 

 when the blue-greens were very numerous. 



Table 56.- Abundance of phytoplankton groups at Station 250 

 in 1929 and 1930. Abun.dance in thousands of 

 imits per liter. 



182 



