Biological Survey — Genesee River 47 



IV. Fishes of the Genesee Region with Annotated List 



By J. R. Greeley, 

 Insinictor in Zoology, Cornell JJniversity 



General Nature of Region. — The entire Genesee valley lies 

 within that part of New York State which was glaciated. In 

 some areas of the region the ice scoured deeply and carved out 

 lakes such as Gonesus, Hemlock or Iloneoye lakes. Other areas 

 were cut less deeply and have gradually filled in, forming swamps 

 such as Bergen swamp. The ice carried a vast quantity of rock 

 and soil southward and deposited much of this material in the 

 Genesee region. 



The streams show tlie influence of glaciation very strongly. 

 The most common type of creek runs over glacial deposits. Such 

 a stream has a hard bottom of rubble, gravel, and perhaps hard- 

 pan clay where the current is strong, but where the current is 

 slow, much of the silt and mud which the water carries settles 

 and the bottom is soft. 



Quite a number of the streams course over a bottom of hard bed- 

 rock. Generally this occurs where the dei)Osits of material by tlie 

 glaciers had caused a change in the course of the stream, as is 

 the case of the Genesee river at Letchworth Park. Some of the 

 rock-bottom streams of the headwaters of the river are believed 

 to flow in their original, preglacial beds, but have cut through a 

 rather thin deposit reaching the shales and other rocks. 



A few creeks of the Genesee region show a bottom of black 

 muck which is a deposit caused by the decay of vegetation. A 

 swamp stream such as lower Black creek (Monroe county) is of 

 this type. In places, however, this creek has a rather firm bottom 

 due to the numerous shells of small clams in the muck. 



Changes in the Character of the Region. — Originally the 

 region was an unbroken area of forest. Within the memory of 

 many peoi)le now living the timber covering has been cut off leav- 

 ing a greater acreage of cleared fields than of woodland. 



These changes which have taken place on the land have affected 

 the waters. Many streams go dry in summer due to lack of forest 

 protection and the great majority of them are open to the sun 

 and become warm in summer. The number of streams cold 

 enough for trout is now comparatively small though an early 

 writer (Turner, 1851, p. 375), referring to the Genesee river 

 above Genesee falls, states that ''speckled trout were plenty in the 

 river, and in all the tributary streams." 



The Genesee River. — The Genesee river rises in Pennsylvania 

 and flows northward across the State of New York to enter Lake 

 Ontario. Like many rivers, it is shallow and swift in its upper 

 ])arts and becomes deep and rather sluggish toward its mouth. 

 The bottom is composed of rubble and gravel in the more rapid 



