Talk Wild Trout Conference 21 November: Pt 1 – The Trout

After months of planning ably led by Fisheries’ Anthony Forster, Taylor Hunt and John Douglas, this event went ahead seamlessly on a sunny Saturday at the Mansfield Performing Arts Centre. Where to start? Well to begin with, I can safely say it was the most positive and successful fishery management event I’ve been to in my 30-odd years being involved with this sort of stuff.

First stop for me was the Delatite River on Friday evening. A school Christmas concert meant I got there a little late and I managed just 15 minutes of fishing and one nice brown on an Antron Caddis, before a curtain of rain came up the valley and sent me running to the car. Back at my warm dry lodgings (thanks Ash!) I actually found myself hoping the rain would continue through Saturday, with the wet  weather encouraging people to come to the conference. But no such luck; Saturday couldn’t have been a better bluebird day.

The Delatite on Friday evening, just before the rain stopped my own bit of wild trout sampling!

The Delatite on Friday evening, just before the rain stopped my own bit of wild trout sampling…

However as things played out, it didn’t matter. I’m guessing nearly 200 people turned up for Talk Wild Trout and it seemed almost all of them stayed until the 5 pm finish, despite several opportunities to escape! (And a sizeable chunk of the crowd stayed on for the Film Festival, which raised funds for the very deserving Mansfield & District Fly Fishers – this club has put a lot of volunteer energy into the whole Wild Trout Program.)

The auditorium filling up on Saturday morning.

The auditorium filling up on Saturday morning.

Far too much happened to cover in a single blog, but I’m getting so many questions about the presentations that I’ll try to put up a few blogs over coming days. (Fisheries will have comprehensive coverage, including a video of the event, up on their website in coming weeks.)  Meanwhile, here’s my take on the trout research so far (snapshots only):

For the 12 priority rivers* surveyed over the 2014/15 season:

  • The Aire, upper Goulburn, Howqua, King, Kiewa, Ovens and Toorongo rivers all had at least one site with more than 50 trout surveyed per 100 metres, bearing in mind that the researchers estimate they only captured between a quarter and a third of all trout present in their surveyed sections. So for actual numbers present, think multiplying those figures by 3 or 4.
  • All had evidence of brown or rainbow trout recruitment in 2014, and most had evidence of both.
  • Surprisingly to me, there was no evidence of brown trout recruitment in the Jamieson in 2014, although there was good rainbow recruitment.
  • Again, surprisingly to me, the Nariel scored relatively poorly with only 8 trout surveyed per hundred metres.
  • The Ovens is showing wild trout recovery from the 2013 fires.
  • Relative abundance of brown trout surveyed in the Mitta (upper) was substantially higher than in surveys in 2005, 2008 & 2011. (The fact the 2011 result was well exceeded was unexpected by me, as we had excellent fishing in the river that year. Having said that, our latest trip was excellent so maybe that fits after all.)
  • The Aire and Toorongo aside (cool climate southern streams) there was a strong trend for trout numbers in all streams to be highest at the higher elevation survey sites.
  • Seven of the larger acoustic tagged trout in the Delatite moved many kilometres upstream when the water temperature exceeded 22 C, then dropped back downstream again in cooler weather. No trout moved downstream when the water warmed. I found this a fascinating result. Although early days (there are still 70 functioning tags out there for this coming summer) this might help explain how the lower reaches of some NE streams can perform well in spring and autumn, but poorly in summer.

More to come…

*Aire, Toorongo, Dargo, Howqua, Goulburn, Jamieson, Kiewa, King, Mitta, Nariel, Ovens & Yarra.

Update; just received a full copy of the proceedings from Fisheries: Talk Wild Trout 2015 Conference Proceedings – Low resolution for email