I received some feedback following the Aberlour meeting last week which I intend to take on board a) keep it short and b) present the summary first then the evidence. As this is a blog post the first point is not applicable, readers can take it or leave it and they are not stuck on hard chair for over two hours! The second point I will adopt here. I will also touch on some of the others points raised during the Aberlour public meeting.
Today we completed the last five surveys in the Avon catchment, three mainstem density based surveys, one on the Water of Ailnack and the last site on the Conglass Water.
The conclusion from all our intensive surveying on the Avon: – juvenile stocks in the Avon are on average as good as they were when monitoring began in 1991.
The evidence – comparison of results from sites with a long history of surveying.
The timed mainstem Avon surveys I reported on a couple weeks ago were a new approach for that river so I was keen to repeat some more of the density (area) based surveys that were held on file as they would provide a more direct comparison with historical figures. The upper site today was above the Linn of Avon upstream of Inverloin Bridge.
The next site was 6m downstream above Dalhestie. Even in the current low water the Avon here was about 20m wide. We surveyed a transect across the river about 12m long.
The third Avon site was at an island below Dalhestie.
On the way up we passed the Water of Ailnack which for some reason had never been surveyed by the Foundation. After tracking down the keepers house permission was received to carry out a survey. The Ailnack is inaccessible to salmon about half a mile up from the confluence with the Avon although considering that the average width at the site was 13m the short accessible area provided room for significant smolt production.
The last site today was the usual monitoring site in the lower Conglass at Ruthven Farm.
A full report on all the Avon monitoring sites will appear in the Spey electrofishing report 2013 in due course, the above is just a synopsis of todays results.
Whilst juvenile stocks in the Avon appear to be good this year, only a fool would suggest that the numbers of adult salmon and grilse are returning in anything like the numbers seen in the past. Jimmy Gray, the retired river superintendent, and many others have described to me how the bottom of the pools in the Avon used to be red in colour close to spawning with the accumulation of coloured cock fish. That is just not happening at the moment with the poor marine survival but last year and the previous year there were still adequate numbers of spawning fish to populate the river with fry. It is clear now that despite the relative low abundance of spawning salmon last autumn incubation conditions were good for fry over the winter, with summer survival of fry and parr also good. Perhaps we are fortunate to have such good recruitment from a limited stock of spawning adults last year but the evidence shows that juvenile densities in the Avon are at least as good as those recorded over the last 20 years.
Whilst we have new electrofishing equipment the bits in the water are still the same as they have always been: a stainless steel ring anode and a copper braid cathode; the gubbins in between just provide the power and better control of the settings. The survey technique used today has not changed since the SFCC established its protocols in 1997 (I think!) so direct comparison with previous surveys is justifiable.
We have gathered a lot of data from the Avon this year but we won’t do much surveying in this part of the river again until 2016. Hopefully juvenile densities are at least as good then, and hopefully adult stocks will have returned to something like the abundance seen only a few years ago.