ASLO's most frequently asked question is, "What is limnology"? It is derived from the Greek word limne, meaning pool, marsh or lake. While the science started out with the study of lakes, it has since expanded to cover other aquatic environments including rivers, streams, puddles and other bits of water. Because of this, it is sometimes defined as "the study of fresh waters". But that leaves out the saline lakes, brackish ponds, & etc..... So, limnologists usually define it as "the study of inland waters", to distinguish it from oceanography.