Upper Nethy

This is my fourth summer here and I have seen most of the catchment but the Nethy mainstem was one area I had hardly visited. It was good to put that right on Friday and Monday when we electrofished the Nethy tributaries and upper mainstem. The first two sites this morning  at Inchtomach produced good results with plenty of fry and very good parr densities. Interested to see how far upstream the salmon got we made the long 4X4 drive up to Bynack Stable, the site of a former tin bothy which had blown down a few years ago. We were aware there was an impassable waterfall below Bynack Stable but neither Steve, nor myself had seen it.

Before walking downstream to view the falls and to establish a new survey site below we completed one of our occasional survey sites at Bynack Stable.

The site of the former Bynack Stable bothy (the green bit where the pickup is parked). Our electofishing site was 10m upstream of the footbridge. This site was last surveyed in 2012 when only a few trout were found. There were many more trout this year, I think we caught 26 parr in a site 14m long – a very nice population of resident trout. Really good high altitude habitat here.

After a quick lunch we kitted up and walked about 500m downstream to do a timed electrofishing site, just to see if there were salmon present.

The location of survey site TSN31 (Timed survey/Spey/Nethy/31st 500m section from the confluence with the Spey). We fished for three minutes in the left bank channel (right side of the photo). There were plenty fry present, most of which were salmon, although no salmon parr. It was good to show that salmon were present in the Nethy virtually to the waterfall.

This site lies within the RSPB Abernethy reserve.  Deer grazing has been significantly reduced and tree regeneration is much in evidence.

There are not only Scots pines; in the valley floor there were a range of broadleaf trees growing including this bankside willow.

The Nethy waterfall at Bynack Stables, a very picturesque scene on a day like this.

Earlier this year there was a controversy reported in the local newspapers regarding proposed planting of broadleaf trees by the RSPB within the reserve. The debate was between those who saw the proposed planting as interference in the natural evolution of the ancient forest and the owners and managers who felt that the remnant broadleaf tree population was not regenerating as well as the pinewood. I am not qualified to comment on that debate but we observed some of the native tree planting today.

Recently planted, and thriving, birch saplings on the terrace above the River Nethy. From a river ecology perspective the broadleaf tree planting is to be welcomed. The leaf litter will add to the organic matter in the river and should result in a more diverse invertebrate population. It often seems that when we are surveying or visiting burns in pinewood regeneration areas that there is almost a monoculture of scots pine. I’m sure that under more truly natural conditions there would be a greater variety of trees, particularly in the riparian zone. It will be interesting to watch how the tree planting develops in the upper Nethy.

Talking about controversy the Fishery Board was in the past embroiled in its own controversy when the Nethy upstream of the falls was stocked with salmon. Certain RSPB staff members expressed their concern about this, and quite rightly so. Our stocking policy has progressed thankfully but one thing is for sure – management of the Cairngorms and controversy are never far apart.

The Nethy upstream of Bynack Stable. The river was of ideal gradient from this point upstream – perfect salmon habitat if only they could get there – naturally!