None that I'd classify as fish tacos you'd have to try no matter where you are but are also conveniently located in Culver City. That said if you have to have fish tacos and you have to be near Culver City, the fish tacos are my go to on the menu when I'm at Kay & Daves and I've had very good fish tacos at Pinches (though the quality has been hit or miss).
Cant think of a seafood spot in the area that falls into the fresh, healthy category outside of a couple of menu items at Akasha or Waterloo & City. When I want seafood I usually go to BP Oysterette in Santa Monica or Malibu Seafood.
9543 Culver Blvd, Culver City, CA 90232