How fast does a sea turtle swim?

Sea turtles swim up to 35 miles per hour some swim slow and
graceful. The fastest a sea turtle can swim is 22 mph.

How does a  dolphin
  protect itself?

Dolphins swim in groups and smash into a enemy. They swim in pods or schools and hit a enemy 
with there great speed.

do fish sleep?

Yes they sort of sleep and might be asleep  
while there MOVING you just dont know it!

REferences

http://www.ask.com/question/how-fast-can-sea-turtles-swim
http://greenanswers.com/question/how-fast-can-sea-turtle-swim_2/