Wild Trout Fisheries Management Program

By Anthony Forster, Freshwater Fisheries Manager, Fisheries Victoria

Brown and rainbow trout were introduced into Victoria during the 1860s by homesick early settlers pining for a connection to their English motherland. The legacy of this work endures with trout now widespread through most of Victoria’s highland rivers. Today, trout remain among our most popular species and make an enormous social and economic contribution to regional Victoria.

In 2013/14, trout fishers reported poor wild trout fishing in our iconic brown trout rivers. While most avid trout fishers acknowledge trout fishing is often not great in the height of summer, this season was different – catch rates were really disappointing. Follow-up surveys confirmed that trout numbers were down in many rivers. Concerned trout fishers rallied for action and answers.

The Trout Reference Group, a coalition of trout fishing representative organisations was established. They led a successful Recreational Fishing Licence grant that gave birth to the Wild Trout Fisheries Management Program. The three-year program looked to better understand the cause(s) of the decline in wild trout fisheries and the population health of our most valued wild trout fisheries. By involving trout fishers and sharing information, we hoped to be able to improve the management response to this pressing issue.

The outcomes of this work were presented to about 360 trout fishers at Talk Wild Trout 2015 and Talk Wild Trout 2016 conferences in Mansfield. Here are some of the highlights of the Wild Trout Fisheries Management Program, so far:

Climate change and wild trout

It doesn’t matter whether you call it climate change, climate variability, long-term drought or a run of hot summers, trout simply don’t like warm water and the summer of 2013/14 was one the hottest on record. During the last few summers, researchers regularly recorded stream temperatures above 25°C. To put this in context, at 19°C trout feed less often and catch rates markedly fall. At 25°C they almost stop feeding. If these conditions continue and they can’t find cooler water refuge, like shade or higher altitude, they eventually die.

Based on a review of climate scientific literature, Melbourne University’s Dr John Morrongiello found the distribution of Victorian brown trout could decline by as much as 35 to 50 per cent by 2030. Other trout fishing countries are also concerned about the impacts of climate on wild trout populations.

Our trout tracking study in the Delatite River showed a trend for larger trout to move upstream to cooler and forested reaches when water temperatures reached 22°C. Our science and monitoring is telling us Victoria’s wild river trout fisheries are among the most vulnerable to climate change of any in Australia.

Streamside shading

One of the key findings of the Wild Trout Fisheries Management Program was that streamside shading provides critical temperature relief for trout in summer conditions (up to 10°C in some streams).

We also learned rivers that flow east/west receive more sunlight and tend to heat-up more than those flowing north/south. Unfortunately, streamside cover in many of our trout streams has been degraded by livestock grazing and at the larger scale by extreme bushfire events.

One of the direct outcomes of the Trout Management Program was the establishment of a new Angler Riparian Partnerships Program ($1 million over three years across 10 catchment management areas). It will allow anglers to work with Catchment Management Authorities to identify important fishing locations on trout streams that need urgent riparian and instream habitat restoration.

The Wild Trout Program led to a new Angler Riparian Partnerships
Program that will see more fishers help restore streamside shading.
(Photo: Dr John Morriengello)

Brown trout stocking trial

Fish stocking is a great fisheries management tool but it’s not always effective. At the Talk Wild Trout 2016 Conference, delegates learned that after fin-clipping and stocking 20,000 yearling trout across two years in the upper Goulburn and Howqua Rivers, then surveying 18.5 kilometres of river, very few (11 stocked trout) were found.

Similar findings have been recorded overseas. The results suggest hatchery-reared trout have poor survival in these rivers because they are out-competed by wild fish for space and food, while they waste away by using too much energy in high flow environments. There is little, if any, value in stocking trout in rivers when water temperatures don’t support their survival and performance.

Is fishing effort impacting trout abundance?

Anglers often highlight examples of recreational overfishing and or poaching as a potential reason to explain low trout abundance. To test this, we looked at angler catch rates, angler compliance levels and the results of the Tag and Reward Capture Program. After surveying more than 1,400 summer campers along trout streams of the upper Goulburn River basin, we found only around five per cent of fishers were harvesting trout.

Our Fisheries Officers told us that compliance amongst 1,300 fishers was around 97 per cent. After tagging and releasing 100 trout with high reward tags ($100) in the Howqua River, to date, only three tags have been reported. These results collectively suggest there is only low exploitation of trout in these rivers.

Wild trout report cards

A key part of the Wild Trout Fisheries Management Program was to assess the population health of our most important wild trout fisheries. Priority wild trout rivers were nominated by the Trout Reference Group. Researchers using electrofishing equipment (walking or boating) recorded trout abundance and size. A scorecard approach was used to assess 12 priority trout rivers each year and provide health status and useful fishing information in an angler-friendly format. The report card looked at key health indicators including recent recruitment (juvenile fish), multiple size classes, presence of mature fish and an overall rating; recovering, good, very good and excellent. A summary of the 2015 and 2016 results are outlined in Table 1.

Wild trout population abundance can vary widely from year to year in the same river, but can quickly recover when more favourable conditions return.

Wild trout fishery health report card summary

Priority wild trout rivers20152016
Aire RiverExcellentNot sampled
Dargo RiverModerateGood
Upper Goulburn RiverGoodModerate
Howqua RiverVery goodExcellent
Jamieson RiverModerateLow
Kiewa RiverExcellentExcellent
King RiverGoodGood
Mitta Mitta RiverExcellentVery good
Nariel CreekLowGood
Ovens RiverRecoveringModerate
Yarra RiverGoodNot sampled
Barkly RiverVery goodNot sampled
Merri and Hopkins RiverExcellentNot sampled
Morass CreekVery goodNot sampled

A partnership approach

Beyond science and discovery, the Wild Trout Fisheries Management Program finds common ground between the interests of fishery/environmental management agencies and trout fishers like never before. The conferences have been so successful at engaging trout fishers and sharing information, this approach is now being rolled-out as a model to engage other recreational sectors including Murray cod, tuna and Port Phillip Bay.

The Wild Trout Fishery Management Program has managed our collective expectations that the performance of our trout fisheries is almost wholly dependent on environment and climatic conditions. There will be good and bad years, but that’s the nature of wild fisheries. By working together we can build resilience in our wild trout fisheries by, keeping cattle out of streams, planting trees along rivers and monitoring our iconic trout fisheries into the future. This will enable us to be more informed and responsive as we look to sustain and develop our trout fisheries into these challenging times.

Recommended for you

Subscribe to our mailing list

Join our 50,000+ subscribers in receiving our Fishing Lines News delivered straight to your inbox. Don’t miss out on all the issues affecting your fishing, projects improving your fishing and opportunities to have your say about your fishery.

* indicates required
Communication Preferences (tick all that apply)