NOAA- National Oceanic and Atmospheric Administration
Earth's Oceans- Enchanted Learning
Jean-Michael Cousteau: Ocean Adventures (PBS site, includes videos)
U.S. Fish and Wildlife Service Educator's Page
PetEducation.com- marine aquariums
Woods Hole Science Aquarium: Fish FAQ
Fish and Wildlife Research Institute
Live Science: All About the Sea
Thinkquest: Deep Sea Creatures
Cryptozoology: Legendary Sea Creatures
Sea Creatures that Can Hurt You
National Geographic: Giant Sea Stars and other "Unknown" Sea Creatures
NOVA online: Deep Sea Bestiary(PBS)