Fishing Reports index > July 2008

Trout chasin’ with Chris Dore

Springtime in the Estuaries
Along our Southern coastline four major rivers enter the Pacific Ocean. The Waiau, Aparima, Oreti and Mataura are all renowned fisheries, each with unique characteristics and trout aplenty.

Their middle to upper reaches are deserved of their reputations as world class trout fisheries, and produce many trophy browns each season.

While anglers naturally flock towards the headwaters of these rivers, the lower estuarine reaches remain largely unmolested.

It is these tidal waters which can provide some of the regions finest springtime trout action, as the annual run of whitebait progresses.

The brown trout resident to these lower reaches have access to massive quantities of seasonally abundant food, and dine accordingly upon smelt, mullet, crabs, bullies and whitebait. With all this nutrition at their disposal, estuarine trout will put on condition and weight much faster than their headwater cousins, who rely predominately on invertebrate drift.

I will here make the distinction between estuarine trout and true ‘sea running’ fish.

Estuarine trout will live in the tidal waters year round, feeding on the aforementioned items. In leaner times, they may swim out to sea with the tides, and feed upon smaller ocean forage species, returning to the river when the estuarine ‘larder’ restocks. These fish are often lighter colored than the upstream residents, but with a definite brown coloration.

True sea run trout on the other hand, will live much of their lives at sea, returning annually with the sole purpose of spawning. These fish are exquisitely marked, with bright, silver flanks and ‘x’ shaped markings present above the lateral line. Many of the fish encountered in the lower reaches of our rivers are mistakenly labeled as sea runners, when in fact, they are estuarine residents, available year round.

It is the whitebait which attract the most springtime interest, drawing both sea runs fresh from the ocean, and post-spawned upstream residents, which drop back into the tidal reaches to take advantage of this abundant delicacy.

The main run of inanga occurs from September through November, when large shoals can be seen along the river margins as they migrate upstream in their millions.

Inanga spawn amongst streamside vegetation near the upstream limit of the transitional zone between fresh and saltwater. This can be a productive area for anglers who target predatory trout on the higher tides.

Both resident and sea running trout will follow the migration upstream, with many of the larger fish continuing on to the tributaries and headwaters of the main river, where they will thereafter reside.

(Research indicates that many of the larger fish encountered in the headwater streams are likely to be a previous years spawning run, which after migrating upstream from the estuaries have displaced their smaller and slower growing headwater relatives.)

The best time for the angler to target these whitebait-feeding browns is on the outgoing tide.

Being weak swimmers, whitebait cannot compete with the tides, and so use the currents to their advantage.

They will enter a rivermouth on the incoming tide, staying deep in the channels and often scattered about the river rather than tightly schooled.

As the full tide turns the ‘bait’ are pushed out towards the edges, and so school for protection. This is where they are most vulnerable to predation.

Trout will become extremely aggressive when feeding on whitebait among these shallows. They will dart in from the channels and ‘plow’ through the shoal, before returning to feast upon those fish wounded by their initial charge.

All this happens in ‘quick time’ and the angler must be ready to punch out a fast cast before the trout moves on. Keep your fly at the ready, with enough line outside of the tip to enable quick loading of the rod.

Streamers are the order of the day, size 8 – 10 baitfish imitations.

Grey ghosts are the norm, but as the whitebait near the end of their run they will grow darker in color due to pigment change.

Here, the angler who carries a darker bodied imitation does so to his advantage.

When stalking trout in the estuarine shallows I employ a weight forward, floating line, used in conjunction with an intermediate polytip.

Eight and ten pound tippet is essential to absorb the often-aggressive strike.

If fishing the incoming tide and the whitebait are running deep, a type 2 sinking line with a short, mono leader will present your imitation at the correct depth.

My retrieve is always erratic to imitate a wounded or distressed baitfish. I will vary the speed of my retrieve, and the length of the stripping will vary from between a few inches in a heavy current to around 10 inches in slack water. Remember that whitebait are not strong swimmers, and make slow progress into the flow.

One of the most consistent producers of large, estuarine trout is the Waituna lagoon, a short drive from Invercargill.

When open to the sea, the Waituna can provide spectacular fishing for above average sized sea runs, although coastal southerlies can make this location unbearable to those without adequate apparel.

Concentrate on the edges in the fashion described, and watch for shoals of ‘bait’. Cover the water methodically, and be assured the trout are never far behind!

The large tidal estuaries of the Catlins hold large residents year round, and they too become vulnerable to capture when they enter the shallows to gorge on whitebait.

The Owaka, Catlins and Tahakopa estuaries are open year round, and access pamphlets are available at most sporting stores.

Springtime estuary fishing can provide a welcome relief from winter hibernation, and as well as offering the opportunity to catch some truly large trout, will help to hone your skills for the coming season.

Chris Dore
FFF Certified Fly Casting Instructor.
Queenstown, NZ
027 693 3027

Chris Dore is an independent fishing guide; his reports are not officially representative of Fish & Game NZ

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