AGU - American Geophysical Union Save
Earth, oceans, atmosphere, space, and planets. AGU is an international scientific society of 35,000 members. Dedicated to advancing the understanding of Earth and its environment in space and making results available to the public.
http://earth.agu.org/   

American Society of Limnology and Oceanography Save

http://aslo.org/   

Help build the largest human-edited directory of the web
Suggest a site | Open Directory Project | Become an editor