1.9 p. p.m. of free carbon dioxide. Gas bubbles 

 rose through the water from the decomposing de- 

 posits. 



Detritus was found on the shores and in the har- 

 bor at all times. Sludge deposits seemed to cover a 

 good portion of the eastern half of the harbor; the 

 continual rising of gas bubbles indicated decomposi- 

 tion at the bottom. These bottom deposits make the 

 harbor unsightly at times, since they are easily 

 stirred up by freighters. 



There can be no question of the existence of 

 critical conditions in Erie Harbor. The existence of 

 these conditions is due, undoubtedly, to the inclosed 

 nature of the harbor, which makes it a natural sedi- 

 mentation basin. Consequently, the effect of the 

 wastes is more pronounced in the harbor, where the 

 greater part of the decomposition takes place. The 

 effect on the lake water is not as great as direct ad- 

 dition would be, since much of the waste is decom- 

 posed in the harbor. Water issuing from the harbor is 

 almost in critical condition at buoy No. LA, but has 

 been greatly improved by the time it has been di- 

 luted and canied to buoy No. 1 (fig. 41). 



The sulphite pulp miU of the Hammermill 

 Paper Company empties a considerable volume of 

 waste into the lake outside of the harbor along the 

 south shore. This mill has a pulp capacity of 

 240, 000 pounds per 24 hours. The waste from such 

 a mUl undoubtedly produces critical conditions near 

 its point of entry. There is the possibility that the 

 low oxygen saturation at black buoy No. 1 was part- 

 ly due to this sulphite waste in addition to the har- 

 bor wastes. 



Port Burwell and Port Stanley 



Any additions to the lake at Port Burwell did 

 not show in the analyses of samples taken at station 

 31 throughout the summer. Surface conditions were 

 always normal, while bottom conditions varied con- 

 siderably because of temperature changes. 



The harbor water at Port Stanley showed low 

 oxygen saturation in July and August. In August 

 conditions were worse than in July, since free car- 

 bon dioxide with a correspondingly low pH value 

 was found. The amounts of clayey matter suspended 

 in the grayish -brown harbor water was so great that 



indicators added to the samples were rapidly ab- 

 sorbed. This absorption may account for the low 

 oxygen saturations. 



Station 32 off Port Stanley was normal at all 

 times during the summer, so that even if the harbor 

 water at Port Stanley was slightly polluted, it had 

 little or no effect on the lake. The harbor water of 

 Port Stanley was safe for fish, as small fish were 

 taken in the plankton hauls made in the harbor at the 

 times when the conditions were worst. 



Ashtabula 



At Ashtabula Harbor the Ashtabula River empties 

 into the lake. The presence of polluting materials 

 in this river was obvious and the condition of the har- 

 bor water was made to appear worse because of the 

 additions of iron ore from the ore docks. This sus- 

 pended iron imparted a characteristic red color to the 

 water. 



On the June, July, and August cruises the chem- 

 ical conditions at station 37 were normal. This sta- 

 tion lay about 2 miles directly off Ashtabula Harbor. 

 The low oxygen saturation found at the bottom of 

 this station in June was due to the penetration of a 

 cold water layer to within 2 miles of the harbor. The 

 chloride content of the water was steady at this sta- 

 tion, with the exception of a slight lowering in July. 



On August 17, samples were taken at four places 

 in Ashtabula Harbor. The first was taken about 50 

 yards above the bascule bridge, the first bridge over 

 the river. The second sample was taken at the end 

 of the ore docks while the Shearwater lay in mid- 

 channel, northwest of the end of the east dock. The 

 third sample was obtained about 50 yards southeast 

 of the west breakwall light. The last sample was 

 taken in the channel about 50 yards off the harbor 

 entrance. 



The results of the analyses of these 4 samples are 

 plotted in figure 42. From these data it will be seen 

 that critical conditions existed in the river above the 

 bridge. By the time the water had reached the ends 

 of the docks it had recovered greatly, but still showed 

 signs of pollution. However, the samples at the 

 breakwall, both inside and out, show that the water 

 was almost normal at these points. 



117 



