In 2001, as part of “Report Series 2: Biodiversity Conservation of the World’s Lakes: A Preliminary Framework for Identifying Priorities”,  LakeNet identified 250 lakes in 73 countries as initial priorities for biodiversity conservation based on available data on fish, mollusc, crab, shrimp, and bird biodiversity supported by each lake, and the rarity of certain representative types of lakes.  Identified lakes are both fresh and saline, permanent and seasonal, natural and man-made. 
    LakeNet’s Latin America and Mexico Lake Biodiversity Conservation Priorities are based on a 2003 revision (still in progress) of the initial list of 250 priority lakes based on feedback and newly available information from the Ramsar Bureau, LakeNet’s global network of individual and organizations in over 90 countries, and other reliable sources.  The 2003 revision seeks to begin to rectify the bias in the first study toward European lakes (where more key lakes have been added to Ramsar) and the relative dearth of highly biodiverse lakes in developing countries due to insufficient biodiversity data.