Blue Remains(2001)

In a world laid waste by nuclear war, Amamiku guards the seeds that hold the genetic code of the planet and can be used for its rebirth. Living underwater and protected from the radioactive atmosphere above, she impatiently waits for the earth to be ready for the seeds to germinate.But when her existence is discovered, it sparks a frantic race between the remains of humanity struggling for survival, and the disembodied brain. This fanatic being has programmed his robotic army to destroy them.