Introduction. 



CONTENTS 



Page 

 1 



Study area 1 



Materials and methods 



Physical data 



Chemical data 2 



Biological data. . 2 



Limnological characteristics, 1967-68 



Water temperature ° 



Turbidity 8 



Conductivity and salinity 



PH 



Dissolved oxygen 



Phosphate 



Silicate 



Calcium and magnesium 



Sodium 



Chlorophyll a_. 



Zooplankton 10 



9 

 10 

 10 



10 

 10 



Comparison of data between years 11 



Acknowledgments 13 



Literature cited 13 



