Welcome to the South Island. The limit is the same for salmon throughout the South Island ie: two fish. In some high country lakes you are allowed up to four landlocked salmon. These are the same fish but they don’t grow anywhere near as big in the lakes where they are mainly plankton feeders.
Fishing hours are the same as for trout.
Salmon fishing from the wharves in Otago Harbour is mostly done by fishing dead sprats under a bobby float. You are allowed to use a second rod to jig for the sprats while your salmon rig is in the water. Small yelloweyed mullet are also used.
I would pay a visit to Ellios Gun Shop in South Dunedin. They will point you in the right direction where fish have been caught recently and advice on salmon rigs to use.
A drop net is a must in the harbour as there is no show of lifting a 20 lb salmon from the water with your rod. You are allowed gaffs in Dunedin but you need to fish where there are steps to get close enough to the water to use it. If you don’t have a net sure enough you’ll loose the fish and kick yourself all the way home!
There is a bit more about it here: https://fishingmag.co.nz/otago-harbour-salmon.htm
Yes treat the same as wild trout. Get the fish into ice immdeiately if possible.
Salmon fishing is one percent high excitement and 99 percent dogged persistance. I once arrived at the mouth of the Rangitata River for a salmon fishing holiday. We arrived late so I slept in. It was late morning before I headed down to the mouth on the motorbike. After just 15 minutes I was back at camp with a 26 pounder. My wife refused to believe that I had just caught that fish. She insisted someone had given it to me as a joke! I mention this because at the same time another couple had been staying there for three weeks before we arrived. Despite both of them fishing all day for the three weeks neither of them had touched a salmon! You just never know with salmon fishing. Persistance is the thing. You might even catch two per day every day!
May the fishing gods shine on you! Please let us know how you get on.