Have done quite a bit around dunedin, but also a bit in the catlins too. Have fished the off the back of the rocks at porpoise bay but no real luck, apparently there a blue cod there though. Have fished the waikawa wharf and had red cod wrasse spotties but aparently you get the odd 7 gill shark in there as well as the odd salmon and sea run trout. Hope this was of some help. My advice would be to look for areas of rock/kelp, with ledges dropping off into deep water quickly won't be a heap round at this time of the year, mainly just blue cod.