34 ILLINOIS ACADEMY OF SCIENCE 



Lake Poopo at 12,000 feet elevation in the Bolivian 

 highlands, is nearly unapproachable, hence there is a 

 total lack of native facilities, and it was possible to do 

 shallow water fishing only. The lake shores are ex- 

 tremely flat. The fluctuations in level carry the shore 

 line back and forth more than a mile from season to 

 season. The writer was able to wade more than a mile 

 out into the lake at its lower level before reaching water 

 that was above the knees. In addition to the seasonal 

 fluctuations there are changes in level of shorter periods, 

 apparently almost diurnal. They are probably due to 

 the wind rather than to the existence of a seiche. Though 

 more than fifty miles long, and half as wide, the lake has 

 a maximum known depth of but thirteen feet. 



The literature is flatly contradictory as to the salinity 

 of the water of Lake Poopo. It is in fact quite salt and 

 non-potable. However the writer and attendant were 

 able to subsist four days upon strong tea made with it. 

 So far as observed the salt has no effect upon the fish 

 fauna. The Rio de Juli in Peru is considerably more 

 saline, yet is inhabited by the same fish as the adjacent 

 freshwater creeks. Even Lake Titicaca is slightly salt, 

 at least locally. This is not evident to the taste in most 

 places. Some rivers of the altiplane are extremely saline 

 and have no fish. Such are those about Urora, Bolivia, 

 which thus resemble Laguna Salinas mentioned above. 

 Other rivers vary seasonally in salt content. R. de 

 Lampa in the rainy season has no taste of salt. But Mr. 

 F. H. Gnindy reports that at Maravillas during the dry 

 season the Indians scrape salt off the rocks of its bed. 

 Lake Poopo is probably less salt than it would be did 

 its surplus not overflow annually into the Salar of Coi- 

 pasa. Here, at Laguna Salinas, and elsewhere salt is 

 recovered on a commercial scale by leaching it out of 

 salty earth. 



In the Rio de Poopo occurs a spring of superheated 

 steam and water. This water mingles with and is grad- 

 ually tempered by the water of the river. Small siiches 

 were observed in water of considerably more than 100° 

 F. The same phenomenon occurs at Aguas Calientes in 

 southern Peru. 



