lOO Roosevelt IVild Life Bulletin 



23. StaJiahe Lake: Formed b}' enlarging a small natural lake in 

 the western part of the Park; also known as Carr Pond. The 

 enlarged lake is about three quarters of a mile long, half as broad, 

 and has a depth of about 25 feet. 



24. Summit Lake: Lying between Forest and Twin lakes it was 

 formerly a small natttral lake which was increased to its present 

 size some forty years ago. Judging by the topography of the bottom, 

 as shown by numerous soundings, the original lake was about half 

 the size of the present one. At present the length is six tenths of a 

 mile, the breadth a sixth of a mile, while the average depth is 20 

 feet and the maximum depth 2'j feet. 



25. 26. Upper and Lower Tzvin Lakes: These lakes are found 

 just outside of the Park, and both are natural lakes. Upper Twin 

 Lake has a length of three tenths of a mile and is reported to be 

 100 feet deep. A dam built at the outlet of the lake in 1841 raised 

 the water level three feet. According to all available information, 

 the depth of the water in Lower Twin Lake has never been increased 

 artificially. The greatest depth found in this lake was 35 feet, and 

 depths of 12 to 15 feet were found seventy-live feet from the shore. 

 The length of this lake is one third of a mile and the breadth one 

 tenth of a mile, 



WATER BLOOMS AND THE FACTORS GOVERNING THEIR 

 FORMATION 



The Nature of Algal Blooms. Anyone who has been upon lakes 

 in the summer, especially in the month of August, has noticed that 

 at times the water is no longer clear, but turbid, the minute particles 

 causing this turbidity generally being green or yellowish green in 

 color. This change in the condition of the water may take place 

 in a few days and then persist for some weeks, or it mav disappear 

 in a few davs and the waters resume their original clearness. 

 Although the term " blooming " is generallv applied to this phe- 

 nomenon it is known by various names in different localities, and the 

 terms " working," " fermenting," or " purging " are also applied. 



The cause of this change in the condition of the water is a fre- 

 "quent subject of debate to the dweller at the lakeside, but microscop- 

 ical examination of the water has shown that in every case it is 

 brousfht aboiit bv the presence of large numbers of microscopic 

 organisms, general!}- minute plants knowTi as algae. The algae 

 form the simplest group of plants and are not composed of leaves, 

 roots and stems, but of single cells — the units of structure which 

 make up the higher plants, — or they may comprise a number of cells 

 that form a chain or other simple structure. The number of fresh- 

 water algae recog-nized by the botanist is verv large and includes 

 the green thread-like scums of ponds and ditches, the moss-like 

 gro\\i;hs in the beds of streams or along lakeshores, as well as the 

 mat-like growths that can be noted at times on the muddy banks 

 or on the shallow bottoms of lakes. 



If a funnel-shaped net made of the finest miller's bolting cloth is 



