Otago Weekly Fishing Report - 30 March 2023

Be prepared to change it up

Following the recent southerly blast that swept through the region, providing an early preview of the upcoming winter conditions, anglers may be pleased to know there is a slight improvement in the weekend forecast.

With temperatures expected to rise above single digits, there is a glimmer of hope for those who have been waiting patiently to get back on the water.

Although scattered showers are forecast across the region, the light winds in most areas mean that fishing is still a possibility for those who are prepared. It will be important to be mindful of the changing conditions and adjust fishing techniques accordingly.

Pictured: Lovely still autumn morning with anglers flyfishing at Poolburn Reservoir. Credit: Garth Johnson.

Don’t let jetboats ruin your day

Extra care is needed if heading out fishing on larger rivers this weekend, with an increased presence of jetboats on Otago’s rivers.

There are planned jetboat races on the Dart and Matukituki over the weekend, as well as increased river traffic as hunters access their roar blocks on the Makarora and Hunter. Jetboats can be a serious hazard for unsuspecting fishermen as well as disturbing the water and spooking feeding fish. Some anglers say jetboats get trout feeding by stirring up the bottom. But if you’re looking for a backcountry fishing experience without the interruptions or risk, try picking a waterway where you won’t get affected by a jetboat this weekend.

Small rainbows create opportunity

There has been a recent influx of small rainbow trout moving onto the flats at the top of Lake Dunstan. Fish & Game officer Ben Sowry has seen a large number of these small rainbows actively feeding on the flats and surrounding weed beds. The average size of these fish is about 100mm.

This increase in rainbow trout population coincides with a decrease in the number of brown trout seen in the same area, which is likely due to the start of the brown trout spawning season. This provides an opportunity for anglers to target larger trout looking to predate upon these smaller rainbows. Ben recommends using large soft baits and spinners to imitate these small rainbows.

 Top of lake Dunstan near Bendigo scenic reserve, where large numbers of small rainbow trout have recently been seen. Credit: Ben Sowry.

Right on the edge

Tim from Central Otago Hunting & Fishing says anglers looking for some action should consider fishing the river mouths of the larger lakes, particularly where discoloured river water meets the clear lake water.

Trout are known to patrol along the edge of the discoloured water, seeking out fish and insect life discharged into the lake. This provides a unique opportunity for anglers to target fish that are actively feeding and potentially catch some excellent conditioned trout.

When fishing at river mouths, it's important to pay attention to the changing conditions and adjust your techniques accordingly. Tim recommends using bright patterns that resemble small baitfish or aquatic insects, such as streamers, soft baits, or mayfly imitations. The mouth of the Timaru River on Lake Hāwea and the mouth of the Matukituki on Lake Wānaka are two hotspots.

Backcountry trout still looking up

Even as the temperature begins to cool and trout prepare for spawning, they can still be caught on dry flies, says Santillan from Hunting & Fishing Queenstown.

As the water temperature decreases, fish become more active and feed more aggressively in preparation for the winter months. Santillan reports that during a recent backcountry fishing mission he experienced multiple brown trout rising to take small dry flies. He found the best time to target these fish was during the early morning or late afternoon when the water is at its warmest. Matching the hatch is very important this time of year, as there can be a range of hatches occurring throughout the day. Hatches commonly include caddis, mayflies, and midges. So, it pays to have a range of sizes and patterns in your fly box to cover the bases. If no trout are actively rising and don’t rise to your first well presented cast, don’t be afraid to switch to a dry dropper or, if fishing skinny water, a straight nymph.

A nice brown trout which couldn’t resist rising to a size 14 Parachute Adams on the Manuherikia river. Credit: Mason Court. 

Upper Clutha’s edges

Good numbers of well-conditioned trout are coming to the bank on the Upper Clutha. Mark from Southern Wild in Wānaka reports anglers having success fishing the edges and slower water up towards Albert Town and Deans Bank.

Often trout will hold in rivers behind trees or rocks, which provide cover and protection from the stronger currents. These structures create a break in the water flow, allowing fish to conserve energy and wait for food to drift by.  Mark says there has been a lack of dry fly activity on the Upper Clutha and suggests the best methods are running weighted nymphs or streamers if flyfishing Deans Banks. If fishing further down river where spin fishing is allowed, he recommends trying lightly weighted black and gold or glitterbug-coloured soft baits or small blade spinners to entice a bite.

Poolburn shallows

The recent southerly blast has significantly lowered air and water temperatures, creating an ideal opportunity to revisit reservoirs in the region affected previously by the harsh summer heat.

One such reservoir is Poolburn where brown trout are now moving back into the shallows and therefore accessible to shore anglers once again. During autumn the main diet of these fish consists of bullies, koura, and mayflies. To imitate the small bullies that inhabit the lake, Ryan from Dunedin Hunting & Fishing recommends using small soft baits or streamers. When using streamers, it is advisable to run a sinking fly line or a sinking polytip to get the fly near the bottom where trout are feeding. Popular streamer patterns include woolly bugger, Dore’s glister and Hamills killer.

Garth Johnson with a nice 7lb brown trout caught fishing a black marabou on a sinking line up at Poolburn Reservoir. Credit: Andrew Hunter.

A screengrab of the Clyde Dam webcam taken at the time of writing.