Wings Against the Sea by Ijasan Adelehin- Paid

Winged creatures and Gilled ones. And they are natural enemies of each other, quite like the eagle and the salmon ... except of course, there's no eating involved. Here's the blurb: MIKAEL is the young winged myaegle who has gone against his world by falling in love with FREA, one of the inferior sea people. The myaegles are outraged; a child—gods’ forbid—must not be born out of the union but Frea is very near delivery, and she’s making her way steadily through the ancient and haunted forest, towards the sea. Mikael, the only person who can save her, has been locked away in a dungeon slated for a horrible execution; and on her path is an array of fiendish foes: One of them is khi, another is Guirerra the terrible, and yet another, is a legion of sabre-toothed apes.… Would Frea make it to the sea?—where safety even, is not guaranteed. Would she ever see Mikael again? In this fast paced, adventure packed, epic fantasy, discover a breathtaking world that is as surreal as it is eerily familiar. A world where some men touch the clouds and others pick corals from the bottom of the sea.…