102 Conservation Department 



at the surface, mid-depth, and bottom throughout the area it is 

 possible to safely say that the lake as a whole is remarkably free 

 from pollution. In harbors and along the shore in places the 

 water is often badly polluted, but these are purely local problems 

 and effect in no way the lake as a whole. The churning action in 

 the shallow water about the margin of Lake Erie, which is choppy 

 most of the time, aerates the water and in the presence of sun- 

 light dilutes and quickly eliminates waste products. At Dunkirk 

 the area within the breakwater was badly polluted,* the bacterial 

 count being almost beyond computation, and the water absolutely 

 devoid of oxygen. However, a quarter of a mile off the mouth of 

 the harbor the water contained an abundance of oxygen and was 

 without a trace of pollution of any sort. The oft repeated state- 

 ment that industrial waste from the Detroit river and the cities 

 at the western end of the lake is invading the eastern area and 

 destroying the fishing is without foundation. Nowhere in the 

 open lake was abjectionable pollution of any kind found in the 

 water or silt deposits located on the bottom. The lake survey 

 did not extend into the Niagara river, for once the water passes 

 from the lake it never returns, and thus did not form a part of 

 the problem. The New York State Conservation Department 

 included this area in its survey of the streams and along shore 

 waters and its findings are given in another part of the report. 



Biology. — The various objects of the biological investigations 

 I have already mentioned, and although space will not permit 

 me to describe all of the results I shall mention a few of the most 

 significant ones. 



Starting with the production of food materials, as a shallow 

 lake, Erie should offer the greatest possibilities for rich animal 

 and plant life, and our results indicate that those possibilities 

 have apparently in no respect been diminished. The chemistry 

 was found to be normal chemistry of lake water, and the plank- 

 ton occurred in almost unbelievable abundance. I can best des- 

 cribe it, perhaps, by making a comparison with the ocean. One 

 of the richest areas of plankton life in the western Atlantic is 

 the Gulf Stream, and yet hauls made during the same week in 

 July with the same size and type of net in Lake Erie and in the 

 Gulf Stream off New York City yielded the following results : in 

 five minutes ten times the amount of plankton was obtained in the 

 lake as in a two-hour haul in the ocean. When one considers 

 the abundance of life which the ocean plankton supports it can 

 be seen that certainly food is not a problem in the lake. The fish 

 supply has diminished, but their food has not, and at the present 

 time Lake Erie could support several times the number of fish 

 now existing tliere. 



A striking characteristic of both the microplarikton and macro- 

 plankton was the inequality in horizontal distribution quantita- 

 tively and qualitatively. Production of both plants and animals 



* See report of F. E. Wagner, page 121. 



