Dunedin advice needed

G'day all I've recent got into rock/surfcasting in Dunedin I've tried the spots I've heard of before such as gun emplacements wharf taieri mouth were surf meets river where it's real deep. With not even a nibble we had two old fish frames as berley but no joy we tried small hooks etc we found one other spot where there was a heap of banded wrasse think some people call them kelpys I caught 5 two of which were quite large! Any way I put them back unharmed after some research I learnt they are very slow growing and also if there's a few of them it's sign of a good fishery? We are trying to catch just a feed for the table. Don't know what ya catch in Dunedin but was hoping to catch kahawai trumpeter Anythink worth eating I'm quite new to it all. There were also lots of seals were I was if that means anything ?
I'm just after some general advice or tips I don't know any good spots other the the one spot just looking for where I might be going wrong or maybe a different spot. Don't want someone's spot X as I know how long it takes to get a good spot cheers!

This article may be of help.

Surfcasting in Dunedin - The Fishing Website