Lake Tiriara
Lake Tiriara is a lake located in the southern end of the island of Mangaia, apart of the Cook Islands. It is the largest freshwater lake in the island chain. Poor pollution management and agricultural processes in the area have put the biodiversity of the lake at risk. See also 
 List of lakes in the Cook Islands

References

Sources https://web.archive.org/web/20120128032425/http://www.seacology.org/projects/individualprojects/COOKISLANDS_lake2001.htm

Lakes of the Cook Islands
Mangaia