Harbor Light. Samples were taken on six dates in the two years. Only bot- 

 tom sariples are shown. As at Stations 105 and 106, there is an entire 

 absence of evidence of pollution. 



The results reported by Osburn (1926a) for the Maumee Bay region are in 

 essential agreement with those obtained in this investigation. On August 12, 

 1926, samples were taken at four stations near Toledo Harbor ^Lit-.hthouse and 

 Little Cedar Point. Oxygen w as near saturation in all samples except one (a 

 bottom sample), in which it was reduced to 78 per cent of saturation. The pH 

 ranged from 7.8 to 8.U. On August I8, the water at the mouth of Maumee River 

 was 57 percent saturated, and had a pH of 7.8. The water of the bay on the 

 same day was as low as 72 per cent saturated which may have n'sulted from 

 weather conditions unfavorable for photosynthesis. The dH in the bay ranged 

 from 8.2 to 8.U. 



Chloride and Nitrogen 



Table 32 shows the data obtained at the five most important stations in 

 this section. The data are arranged by dates so that it is possible to trace 

 changes in the content of chloride and nitrogen from a point in the river to 

 a point 8.5 miles from the mouth of the river. The stations are the same 

 as those given i;i Table 29 (Stations 2li9 and 25U) . Table 32 will serve also 

 to show the differences in chloride and nitrogen on different dates. These 

 differences were greatest at Station 250 because of the reversing currents 

 of the river. Here, as at the mouth of portage River, the number of samples 

 was too small to show average conditions accurately. However the differences 

 between stations were so marked that the means given in Table 33 show clearly 

 the relative positions of the stations with respect to abundance of chloride 

 and nitrogen. It will be found convenient to refer to this table to get a 

 general view of the situation, and then to Table 32 for details. The upper 

 part of Table 33 gives the riieans for each of the five stations on the four 

 dates common to allj the lower part shows the means for Stations 250, 252, 

 and 25I1 on the six dates common to them. 



Chloride decreased considerably from Station 2U9, in the river, to Sta- 

 tion 25U, far out in the lake. The most marked decrease came between Sta- 

 tions 2I49 and 250. Even on August 28 and September 9, when the current was 

 flowing outward, there was a large decrease between these stations, showing 

 that the water undergoes rapid dilution with water from, the bay as it leaves 

 the river. Another marked decrease took place between Stations 250 and 251, 

 but beyond Station 251 the decrease was slight. At Station 2 5U the mean 

 was about 2 parts per million higher than the mean for the Island Section. 



The nitrogen determinations in the river (Station 2[(9) show that the 

 water was polluted. The abundance of unstable organic matter, as indicated 

 by the albuminoid ammonia was much greater than in the polluted waters 

 reported by Mason, and, of course, much greater than in the Island Section 



103 



