Limnology sites:

Freshwater Ecology
On-line information on aquatic ecology

Center for Annelida Resources
Illinois Natural History Survey, USA

Dissertation Initiative for the Advancement of Limnology and Oceanography (DIALOG)

Great North American Secchi dip-in

Lake Ice Analysis Group (LIAG)
Wisconsin, USA

Toxic cyanobacteria home page

Wetlands of the World
Wetland photography contest

Wikiverse World of Knowledge: Limnology