Most fish are eatable, but many taste like crap.
Never tried doggie, but prepare it like any shark. I know of a few people who eat them.
Skate, the best meat is in the wings. I release them myself.
Moki, some people really like them. Best to only eat the ones just over legal limit and release the larger specimins taste even worst. I have typically cooked them whole in tinfoil with lemon. Bleed and gut them quickly, the meat detroiaties quickly so keep them on ice if possible. Kaikouria is probably better for Moki then canturbury itself.
Most members of the Wrass family are eatable, the meat is quite nice but heaps of bones. I have only eaten them cooked who like Moki.
Threre is also trout in the rivers and lakes which can be eaten.
Must get back down that way myself for a bit of a fish and play around.