Next year we will be electrofishing the Avon so I was interested in the number of redds in the upper reaches. We set off early this morning to rendezvous with the keeper for access through the estate gate. It was a foggy start at Knockando but by Tomintoul it has cleared and it was a cracking day. It is a long drive to the end of the road (one hour in 4 wheel drive) but well worth it for the scenery which is stunning. We saw the eagle take off and fly round the ridge where it was waiting on a rock keeping a beady eye on us. It was hundreds of yards away, just a speck on a rock against the skyline but my camera has a fantastic zoom.
On the way up we were discussing what we expected to find. My hopes were limited, one pair of salmon or a redd and I would be happy, but it turned out a lot better than that.
The Avon is still a big river at Faindouran, 20-30m wide where we started at just below 600m altitude, climbing to 620m. The weather couldn’t have been better, still, mild and bright although the sun soon disappeared behind thin cloud, providing ideal conditions for redd counting. Just where we parked Steve crossed the river to walk up the south side disturbing a fish on the way. A good start, a pair of fish within 50m of the bothy. No sign of a redd in the immediate vicinity but it wasn’t long before we started seeing fresh redds.
The redds were much easier to spot than we thought, there was a cover of algae on the undisturbed substrate making freshly cut redds highly visible. Just opposite the redd above Steve came across one in a shallow glide.
I’ve spent a lot of time watching salmon redds over the years but we found one further up which looked as if it was made by a digger. The pit was about 1 foot deep and some of the cobbles that had been shifted were 6″ diameter. The fish we did see were mostly small salmon/grilse but whatever made this mega redd must have been substantial.
We covered 3km of the upper Avon spotting about 25 redds or so. As stated earlier this was more than expected. 10 redds/km would give an egg deposition rate of about 2/m2 which isn’t too bad. We will be electrofishing up here next summer and I now expect to find fry, although they have been thin on the ground during previous surveys. Even a low density of juveniles in such a big wide river can mean a reasonable smolt output; there may be more production up here than we thought.
We stopped at about 620m altitude (over 2000ft) and just where we stopped there was a small redd midstream. How much further do they go? It is only 4.5km to Loch Avon, could they spawn that high up? That trip will have to wait for another year. At 2000ft these are some of the highest spawning salmon in Scotland, I know of only one other place where they spawn at higher altitude – the Dulnain where we have found salmon fry at 640m.
The juniper was pretty stunted up there, little more than groundcover compared to the 8ft high bushes seen further down.
Mission accomplished we had a look in the Burn of Loin on the way home. At 500m+ this was practically a lowland burn. The redd density was much higher here compared to the upper Avon, most looked like sea trout redds but a dead cock salmon further up showed salmon were spawning also.
The Loin supports a high juvenile fish density, the habitat is good but there must be some better geology in the area to create such a productive high altitude burn.
On the way back to the pickup we found some watervole burrows in an old side channel.
It was encouraging to see reasonable numbers of redds in the very margins of Spey salmon habitat in a year with an apparent low stock of adult fish in the river. Fish this high up are almost certainly spring/early summer salmon and grilse (the falls below will stop any late running gravid fish). The late season grilse were notable by their absence this year but there did appear to be a reasonable early run of small grilse (if you can call the first half of July early). I saw one small fish on the redds today that was about 2lb size; just shows the importance of these early grilse for populating the upper reaches.
There endeth another great day out (best job in the world this!).On the way home we stopped at the Linn of Avon. There were a few fish half-heartly jumping at the falls but what a stunning spot.
We will be doing a lot of redd counting across the river in the next few weeks so if anyone is wanting to assist please get in touch at firstname.lastname@example.org