64 Types of Aquatic Environment 



The Finger Lukes of the Seneca basin in Central New 

 York constitute an unique series occupying one section 

 of the drainage area of Lake Ontario, with which they 

 communicate by the Seneca and Oswego rivers. They 

 occupy deep and narrow valleys in an upland plateau 

 ^{ soft Devonian shales. Their shores are rocky and 

 increasingly precipitous near their southern ends. The 

 marks of glaciation are over all of them. Keuka, the 

 most picturesque of the series, occupies a forking valley 

 partially surrounding a magnificent ice- worn hill. 

 The others are all long and narrow and evenly contoured, 

 without islands (save for a single rocky islet near the 

 east Cayuga shore) or bays. 



The basins of these lakes invade the high hills to the 

 southward, reaching almost to the head- waters of 

 the tributaries of the Susquehanna River. Here 

 there is found a wonderful diversity of aquatic situa- 

 tion. At the head of Cayuga Lake, for example, 

 1 »ey< >nd the deep water there is a mile of broad shelving 

 silt -covered lake bottom, ending in a barrier reef. 

 Then there is a broad flood plain, traversed by deep 

 slow meandering streams, and covered in part by 

 marshes. Then come the hills, intersected by narrow 

 post-glacial gorges, down which dash clear streams 

 in numerous beautiful waterfalls and rapids. Back 

 of the first rise of the hills the streams descend more 

 slowly, gliding along over pebbly beds in shining 

 riffles, or loitering in leaf-strewn woodland pools. 

 A few miles farther inland they find their sources in 

 alder-bordered brooks flowing from sphagnum bogs and 

 upland swales and springs. 



Tims the waters that feed the Finger Lakes are 

 all derived from sources that yield little aquatic 

 life, and they run a short and rapid course among 

 the hills, with little time for increase by breeding: 

 hence they contribute little to the population of the 



