The New Zealand spring is approaching. This means that it is almost time to target sea run brown trout in and around the river mouths of the South Island rivers. These sea run brown trout show up in numbers to chase the shoals of a small transparent fish locally known as “Whitebait”. These tiny fish (about an inch long) swim into the rivers in large shoals and make their way to the upper limits of the tidal regions of rivers. It is here that they wait until the largest tides of the year to spawn in the riverside grasses. These little fish are packed with protein and trout who have locked onto them as a food source will generally be in fantastic condition. As a fly fishing guide I practice catch and release on the whole, however if I catch a maiden sea run trout in good condition it may just find its way into my smoker. The flesh of these fish is often a bright orange colour and tastes amazing.
Sea run brown trout are found right the way around the South Island but my favourite areas are Canterbury, Nelson and the West Coast.
There are a lot of different techniques to target sea run trout with. Threadlining is a simple and popular method. Each year many large specimens are taken on a hard bodied lures. Some are even taken by complete novices or even children. Casting a lure with a threadlining set has the great advantage of covering large amounts of water in short amounts of time. The two most popular hard lures in New Zealand are by far the black and gold “toby” and the CD5 Rapala lures.
Another method I found absolutely lethal as a child was livebaiting with a live bully. I would catch a supply of bullies on a size 16 fly hook under the local wharf. I would keep them alive in a bucket of water until they were required. The rig I used was a single hook ledger rig. I would attach a 2oz sinker to the bottom and tie on a 2/0 hook on about 18 inches up the trace. I would then hook the bully through the bottom lip and drop the rig to the bottom and wait. The wharf I fished from was located at the mouth of the Grey river. This river is absolutely huge when it enters the sea. The volume of water flowing down the river is some much that the tide does not flow in, it just lifts the river level and slows the current down. I found that it was when the current slowed on the incoming tide was bite time on the livebait rig.. I think that this had a lot to do with the movements of the Whitebait through this period also. They would use the reduced current speed to make a dash up the river. One of the biggest pitfalls of this style of fishing is the height of the wharf. Lifting a 10lb to 12lb five meters up onto the wharf was nearly impossible. The only solution I found to combat this was to manoeuvre my defeated fish along the wharf to the nearest ladder that the boat fishermen would use to access their boats.
I have also witnessed lip hooked bullies being cast into faster water and slowly retrieved on threadlining equipment. On the occasion I saw this I was blown away with the results. The fisherman would let the bully swing across the current. When he felt a knock on the line from a fish he would flick over the bail arm wait 15 seconds and wind in the slack and invariable the fish was connected to the line.
A word of caution. Live baiting is not permitted in all waters, so check your local regulations thoroughly. Also hooking fish deeply in the gills is a real possibility. This needs to be planned for, once you have taken the fish you require to eat, call it a day or change methods.
The last method of targeting sea run trout that I will cover here is fly fishing with a streamer. There are many patterns suitable for imitating Whitebait. My favourites are Grey Ghost, Silver Dorothy, Jack Sprat and if there is a little bit of colour to the water I prefer a rabbit smelt pattern.
I like to fish these across and down on a 6 weight set and a floating line. Once I have cast I throw a couple of upstream mends in to allow the fly to sink and begin to retrieve. The takes can be heart stopping! I often select a spot on the river where whitebait build up. The first piece of faster water in the river such as the first rapid. Whitebait will wait here until the tide begins to build and slows the current enough for them to easily swim the rapid. Trout will be found here in good numbers. Also another spot is right at mouth of the river where the outgoing water meets the surf. Whitebait will build here until the tide begins to lift.
I have found that sea run brown trout are an underutilized resource. It is often a time of the year where trophy trout can be encountered. These fish are nearly always in the best condition of their lives and fight like there is no tomorrow. The best months are still ahead of us and I can’t wait to get out there amongst the action!