About this time of year, I start to check for mayfly nymphs on my local lakes in Victoria’s central highlands. Although actual mayfly hatches worthy of the name are still at least 6 weeks away, getting a sense of nymph numbers early will help to plan trips when the season is in full swing.
I should say, my ‘surveying’ is far from scientifically rigorous. It usually involves turning over conveniently-placed rocks, sticks and bark in the shallows during a quiet patch in the fishing. So, if a trout moves anywhere within sight or sound, that’s likely the end of the survey! Therefore, I only cover a tiny fraction of the available habitat, meaning no nymphs does not mean there aren’t any, or even that mayfly season on that water will be poor.
However, if I do find plenty of nymphs without really trying, either it’s an enormous fluke, or it’s looking like good spring hatches are on the cards.
This week, I’ve spent a few hours on a couple of the less-visited local waters, Talbot and Cosgrave; lakes which are easy to overlook when the likes of Moorabool, Hepburn and Newlyn have plenty to offer. As with most lakes in the area, these two are in excellent shape. Both have been full for a while now; Cosgrave looks discoloured from a distance (as it often does) but close up, there’s nearly a metre of visibility. Talbot is somewhat cloudier, yet there’s still a good half metre plus of visibility – more than sufficient to fish blind if you have to.
Both lakes provided just enough downtime for a random mayfly survey. Talbot romped it in, with multiple nymphs attached to the half dozen objects I checked in the shallows. On the other hand, Cosgrave surprised by giving up just a single mayfly nymph. (There was a decent sprinkling of duns and spinners there in autumn.) Still, as I suggested earlier, maybe I just didn’t look in the right spot. The other bigger surprise at Cosgrave, was shrimp – hundreds of them. They were flipping out every time I turned over a piece of bark or wood. At 2-3cm long, they would surely be on the trout menu, although they were too quick for me to grab one for a photo. In 40 years fishing Cosgrave, I’ve never noticed shrimp there – another lesson from Jim Allen’s proverbial 100 page book of flyfishing. (Maybe that’s on page 11!) Food for thought (sorry) when I’m next considering Cosgrave flies.
Two other notes from the week that may be useful. First, I had a quick look at Lake Learmonth. This very broad, shallow lake received 5000 50 gram rainbows at the end of 2022. Historically, this lake has produced some big rainbows when water conditions have allowed trout to survive (it was dry or almost so for most of the ‘noughties’). However, on the rare occasions I’ve visited over the years, it has been extremely turbid and I’ve never been encouraged to persist. Unfortunately, dirty water was a feature on this visit as well. Where I checked, visibility was best measured in inches.
At the other extreme, Wendouree is looking about as trouty as a lake can get, and a quick fish on the northern shore produced a half-hearted follow from a really decent brown. I hear the hatchery has been catching, stripping, and carefully releasing plenty of nice Wendouree fish this winter, so I imagine a committed session on this lake is well worth considering.