Past
A long time ago dinosaurs lived in the sea. There was a giant shark called a megalodon. There were also giant crocodiles that were so big they could eat sharks.
Present
Today the sea around New Zealand dolphns, little fish, crabs, jelly fish, octopus, tiger fish and seals. It has pengins and sharks and snapper. Sometimes ships smash into rocks and let oil into the sea and that's bad for the animals.
Future
In the future the sea will have lots aquariums and lot of sea animals will live in them. That's becasue the sea might be too poluted for them to live there - thats why it's important that we look after the sea and keep it clean. I think that robots will live in the sea and help to clean it up.