Not the best time of the year to be getting out surfcasting unless you’re after dogfish, skate, red cod and a slight chance of a kahawai. Surfcasting at any of the beaches north and south of christchurch is worthwhile over the summer months from around October through to April. There’s a few places around Lyttelton to fish and a few wharfs you can access. You’ll get kahawai, mullet, skate, rig, school sharks, red cod, and a lot of dogfish at times. The wharf at Corsair bay is a nice spot and I caught kahawai and mullet there. A lot of stingrays all around lyttelton over the warmer months as well so if you’re not after them use small baits and keep them off the bottom. Wouldn’t be sure about eating the fish from lyttelton tho but I guess it would be alright. The Pier is I guess an underated fishing spot as you can catch a lot of different species and it’s not far to travel. Get yourself some crabs for bait and head to any of the spots around christchurch and with the right conditions rig/elephant fish will be very easy to catch.
As I said now is not a good time for fishing and at least a few months before most of the species like kahawai start coming back in numbers.