THE NESOI GODDESSES IN GREEK MYTHOLOGY

The Nesoi are a rarely spoken about group of goddesses in Greek mythology, the Nesoi being the goddesses of the islands. 

The Protogenoi Nesoi

Where spoken of, the Nesoi are considered to be Protogenoi, primordial deities of the Greek pantheon, and probably the daughters of Gaia. This would suggest that the Nesoi are the female equivalents of the Ourea, the mountains.
 
There were said to be only 10 Ourea in Greek mythology though, but if each island was represented by a Nesoi, then there would be hundreds of such goddesses. 

The Nesoi in Greek Mythology

Callimachus, the Libyan Greek scholar, talked of the creation of the Nesoi, the islands being created when Poseidon struck down the Ourea with his trident, flinging them into the sea.

​This though, would mean the transformation from god to goddess, and of course, Poseidon was a late comer to the Greek pantheon, born generations after the Protogenoi. 

Naiads or Nesoi

In most surviving texts it is more common to talk of nymphs or minor goddesses being associated with the islands, or at least the water sources on the island. Thus, each island was represented by a Naiad, the freshwater nymph daughters of Potamoi; this Naiad would occasionally give her name to the island, as in the case of Aegina, who gave her name to the island she was carried to by Zeus, and Salamis, who likewise was abducted by Poseidon.
 
Other goddesses, who were not Naiads, were also associated with the island of Greek mythology, for there was also Rhode, a daughter of Poseidon and Amphitrite, who was goddess nymph of Rhodes.
 
The island of Delos is a different case though for Delos was considered in many ancient sources to be the metamorphosed goddess Asteria; Asteria having fled the unwanted advances of Zeus.