n. C. Osburn, Ohio State University. (Bottom fauna). 



R. V. Bangham, College of booster. (Zooplankton) 



L. H. Tiffany, Ohio State University. (Phytoplankton) . 



H. R. Eggleston, Marietta College. (Bacteriology). 



B. ?. Hanan, Rocky River High School. (Chemistry). 



Dr. Osburn, as Director of the Franz Theodore Stone Laboratory of Ohio 

 State University at Put-in-Bay, offered the facilities of the laboratory for 

 the use of the staff. The steam tug, 0^ H^ Perry , and the motor criiiser, 

 Veto , of the State of Ohio's fleet, were available for work on the lake. 

 Eleven Hays in the month of August were devoted to field work. A total of 

 U8 stations were visited. These were established at points in the open lake 

 and near sources of pollution so that some idea could be gained of the extent 

 of pollution. Observations were made of temperature, dissolved oxygen and 

 hydrogen ion concentration, bottom organisms, bacteria, phytoplankton, and 

 zooplankton. The study of bottom organisms and plankton was not quantitative, 

 except in a general way. 



The results of this preliminary study have been published in mimeographed 

 form (Osburn, 1926 and 1926a) , end will not be given in detail here, but will 

 be reviewed in the appropriate chapters. However it may be well to present a 

 rather general statement of the results to form a background for the more 

 detailed data of later years which will be given in the body of the report. 



Numerous localities were noted where the dissolved oxygen was considered 

 reduced, but none where the oxygen deficiency would, of itself, prevent fishes 

 from existing. The lowest observed was 2.6 cubic centimeters per liter (3.7 

 parts per million). Oxygen was found in sufficient quantity almost everywhere, 

 even over bottoms that were foul with decaying matter. In the deeper water of 

 the open lake, even when not far off shore from sources of pollution, the oxy- 

 gen content of the water was never dangerously low. There was an abundance 

 of oxygen near the mouth of Detroit River; in one sanple the water was com- 

 pletely saturated. No acid water v;as encountered; the hydrogen ion concentra- 

 tion ranged from 7.0 to 8.6. 



Sulphur bacteria were found abundantly in the most polluted areas, 

 and the colon bacillus, B^ coli , vjas widely distributed. Enclosed areas and 

 regions near large cities showed large numbers of sewage bacteria, but the 

 number diminished rapidly as the distance from sources of pollution increased. 

 Pollution of shore waters and enclosed bays rendered these areas unsafe for 

 recreational purposes and unsatisfactory as a source of municipal water supply. 



It was noted that plankton was scanty near the mouth of Detroit River, 

 but very abundant in certain areas where there was definite evidence of 

 pollution. 



Considerdble areas of the bottom near the large cities, particularly 

 in the harbors and channels leading from them, were covered with organic 

 debris, which made the area unsuitable for spawning. In some cases, as in 

 Maumee Bay, the steamship channel tended to retain the suspended organic mat- 

 ter and permit it to be carried much farther from the river than it otherwise 



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