What a neat dream! My thoughts are that both sharks and birds are prehistoric creatures.
Sharks only live in the water and most have to keep moving to stay alive. (read that somewhere)
Being a water creature I'd say this would represent some emotional issue.
Birds are creatures of the air. Some, like cormorants, can dive and swim quite well.
I see Air as representing thoughts. Sooo I'm wondering if you are using positive affirmations
or even prayer to help you overcome some long-standing emotional issues.
If not, perhaps this dream is trying to give you help in that direction?