some ocean mobs isnt spawning

dolphin, cods, tropical fish and salmon dosent nutrely spawn(i checked in a few oceans) 

What I expected to happen was...:
that the mobs whould spawn in the world

What actually happened was...:
they didnt spawn

Steps to Reproduce:
1. create new world
2. search for any of this mobs(can use commands)

 

link for world with example: https://drive.google.com/file/d/1lnH3f_On6_1STE1vO7Wf_maJ2ltb1_Us/view?usp=sharing