Life appeared on earth about 4 billions years ago in the primitive ocean, Panthalassa.
In many religions, the Ocean (and water in general) holds a very important place and represents Life, Purity and Fertility. The flooding Nile, purification rituals in the Gange, etc.
In the Egyptian mythology, the Nun is the deification of the primordial watery abyss, from which many gods were born.
It was viewed as the origin of Life, as well as the bringer of Death.
Nowadays, the oceans are being damaged and plundered. Sometimes beyond repair.