Archive for August, 2012

Return to the Rottal Burn

Thursday, August 30th, 2012

 These bulletin blogs represent news about Finavon and the South Esk, and my views as a riparian owner. They are not the views of any other organisation, nor are they designed to promote the interests of any individual or organisation other than Finavon Castle Water and factors affecting the fishery. Tony Andrews

Rottal Burn with Rottal Lodge

The view in the photo above is from Rottal Bridge looking upstream towards  the lodge. It shows what the whole burn looked like before the restoration project, which only affected the burn downstream of the bridge.

Less than a month after my first visit to the Rottal Burn to look at the restoration, I returned to see how work was progressing. I found that the original dredged channel (the ‘Rottal Ditch’ as I call it) had been filled in, and the full flow of the burn diverted into the newly formed channel.

Gravel & Cobble

The photograph above shows the quality of the spawning gravel and cobble in the new Rottal Burn channel.

There was a good level of water when I visited, although the burn was not in flood, my visit being in a rare lull between spates in this extraordinarily wet summer. The clear water and medium level of the burn enabled me to see in detail what had been achieved. There had been a period of high water since the completion of work, and there was ample evidence of subsequent movement of silt and gritty deposits. In sections of the burn closest to the upstream junction with the original dredged ‘ditch’ it was reassuring to see clean gravels and cobbles had already appeared. Further downstream than I had anticipated the effects of this cleaning process can now be seen, with silt deposits on the inside of bends and in the quieter depositing zones of the channel.

Stony channel

Tinca the Labrador enjoying the newly formed riffles in the stony channel just downstream of Rottal Bridge. This photo shows the quality of the gravels and cobbles revealed by the flows clearing away silt.

The gradient of the 1200 metres below the junction with the new channel just downstream of Rottal Bridge is such that flows remain fast, and the carrying capacity of this high energy section of the Rottal Burn should ensure that the cleaning process continues. The only part of the channel where silt deposits are likely to remain for a time at least is the section immediately upstream of the confluence with the main river, where the backup of water in spate conditions will make the last 100 metres of the channel very quiet.

Rottal Burn full flow

View downstream to the ‘chicane’ under the planted bank. This photo clearly shows the appearance of clean gravels and the beginnings of ‘natural’ erosion on the right bank.

Early next year the main tree planting programme will take place, which will involve using indigenous trees to provide bank strengthening, shade, shelter and invertebrate habitat. With climate change predicted to give us warmer summers (joke!) it is important to mitigate against the damaging effects of warmer water temperatures in parts of the catchment used by juvenile salmonids. Dappled shade provided by carefully planted bankside trees can help reduce water temperature, as well as improving habitat in various other ways.

Stony channel

The appearance of the stony channel after only a couple of weeks of full flow can clearly be seen in the photograph above. This is where the adult fish of the winter of 2012/13 will (I hope) be spawning.

I have not commented on the purpose of the Rottal Burn restoration, and therefore how its success or otherwise will be measured. We may assume that the objective is to ensure that the burn produces as many naturally generated and healthy salmon and sea trout smolts as possible. The gravelly riffle of the former dredged channel offered good quality salmon spawning and habitat for fry in the post-alevin stage of life. But, as these juvenile fish grew into parr, there was probably insufficient habitat to retain them in the burn, which may have resulted in them moving downstream to the main river.

Silt on the move

Silt on the move!

After only two weeks of full flow in the restored channel, this photo shows the ridges of gritty sand being pushed down the channel towards the main river by the high energy flow. My guess is that after the floods of the coming winter this silt will have gone, hopefully to reveal substrata of gravels and cobbles. Let’s hope that is the case, rather than more deep silt, which of course is no use as spawning habitat. A good measure for the new Rottal will be if freshwater mussels are able to colonise its gravels. Now that would be a real measure of success!

Wetland in the Rottal Burn 'delta'

Wetland in Rottal Burn ‘delta’, formed by restored section downstream of Rottal Bridge, provides habitat for nesting and feeding birds birds, insects and amphibious reptiles.

 nice wetland picture

Wetland in the Rottal flood plain. This marshy habitat provides the immediate environmental context for the estuary of the Rottal Burn as it enters the main stem of the South Esk. Good quality upland marsh provides nesting and feeding habitat for endangered wading birds, amphibians and a wide range of insects, including dragonflies, damsel flies, lepidoptera (e.g. upland butterflies and the fox and emperor moths) and many other species of birds and insects. Without this context the Rottal Burn restoration would be incomplete.


 Riffle with clean stony bed. Habitat for young salmon. If the morphology of the restored burn continues the process of cleaning and exposing gravels and cobbles of this quality – and there is no reson why it shouldn’t – we can reasonably hope for successful spawning and juvenile salmon and sea trout nursery areas. Time will tell…

 South Esk above new confluence

Above the confluence of the restored Rottal Burn with the main stem of the South Esk

I am not sure whether there are data on fish populations in the main stem of the river, or whether there may have been a threat to parr migrating into the river from the Rottal Burn from predation by resident trout. While electro fishing the ‘Rottal Ditch’ just prior to diverting the full flow into the new channel revealed a high incidence of first year fry, there appears to be a shortage of historical data on survival rates of these fry. In general it is true to state that salmon prefer riffly habitat, while trout like deeper pools. The original ditch was therefore probably better habitat for salmon up to the end of the first year than it was for sea trout. The restored burn channel appears to offer both salmon-friendly spawning and riffle habitat for fry, and deeper pools for trout. How we measure the success of spawning and survival compared to the previous regime remains to be seen. It will be interesting, for example, to see if any radio tagged salmon choose to spawn in the Rottal during the three years of the Marine Scotland project. In the meantime electro fishing should give us some idea of the species breakdown of fry and parr in the burn.

Electro fishing to monitor juveniles

Electro fishing to monitor juveniles

TA 30/8/2012

Grilse arrive in better numbers than expected but generally small and thin.

Saturday, August 25th, 2012

These bulletin blogs represent news about Finavon and the South Esk, and my views as a riparian owner. They are not the views of any other organisation, nor are they designed to promote the interests of any individual or organisation other than Finavon Castle Water and factors affecting the fishery. Tony Andrews

As I write this blog on the 25th of August, the season’s catch totals for Finavon are 82 salmon and grilse and 140 sea trout. This catch is on target for average numbers of salmon and grilse – perhaps a bit better than that – and above average for sea trout. It is a fair and accurate statement, based on observation and catches, to state that all the pools at FCW have fish, and that there is currently a predominance of MSW salmon – well into the upper teens of pounds in some cases. On the other hand, grilse numbers have been low, the fish generally under nourished, and there has been a re-appearance of Red Vent Syndrome (RVS) in about 50% of grilse observed.


View from the suspension bridge upstream to the Flats with Volcano beyond. This stretch of Milton Beat is the plateau looking upstream after the considerable gradient and fast water through Castle Stream, Craigo Stream and Red Brae. The section of River between the tail of the Flats and the Haughs Aqueduct is (I think) the steepest gradient between Inshewan and the sea. The effect of this steep, fast flowing stretch of river is to slow fish down, especially in cold water, and the pools between Tyndals and the Flats therefore benefit from resting fish becoming available to the fly fisherman in ideal depths and flows to catch fish. Milton Beat has in 2012 consistently performed better in terms of catches than the other three beats, although in low water and in the sea trout season all the four beats fish equally well.

This volatile summer has provided ample water for salmon and sea trout to migrate upriver. The result is that fish are now well distributed throughout the catchment, many of which will be well positioned to access the spawning areas when the water temperatutres drop towards the middle of October. Evidence for this claim can be seen in the distribution map of the Marine Scotland tagging project, albeit with only 12 fish marked on the map. 

These variable water levels have given the fish little chance of settling quietly into the main holding pools, such as Boat Pool, Red Brae, Haughs, Melgund and Indies. As levels have risen and the water coloured up with peat stain and gritty silt and acidity, the fish have become reluctant to take. It also hasn’t helped that the Lemno Burn now spews out copious quantities of muddy silt in suspension after the slightest rise in level, which is the result of the dredging done by the farmer (with SEPA authorisation) above Battledykes. However, we have had a brief respite since the 4 foot plus spate last week, with the result that levels have remained good, the water cleared to the clarity of a pale malt whisky, and conditions have become ideal for catching salmon on small flies fished intelligently through the pools.

Grilse from Tyndals

8lbs salmon caught and returned in Tyndals Pool (Milton Beat) on 23 August 2012.

In the last two days we have caught 12 salmon, in sizes from grilse (all a bit thin) of around 3lbs to MSW salmon of 13, 14 and 15lbs. We have been able to reduce the size of fly from size 8 to size 12, and the lightly dressed Cascade has done well. Last evening at about 7pm I took a split-fresh grilse of 5lbs from the fast water at the head of Bridge Pool. It was a lively fish and, playing it in the middle of the pool (where you have to wade to cover the main lies under the north bank) and with the fish cartwheeling down the pool, there might have been the briefest entertainment for lorry drivers on the A90 as they whooshed past on their way to meet their end of week delivery deadlines.

 Willows in good water

Willows in good water for a salmon, grilse or sea trout. FCW’s top pool. I know I have promised to write about Willows Pool on Milton Beat, which, over the years, has outperformed all other FCW poools. I should get round to doing that soon. In the meantime this blog suggests at least one of the reasons why Milton Beat has fished so well in 2012, and of course Willows is the heart of the beat.

As we move into the last two months of the 2012 season, the quality of fishing at FCW will depend, as it always does, on reasonable autumn flows and sufficient salmon to provide our visitors with, at the very least, the spectacle of salmon showing in the pools. If we have a late run of MSW salmon we can expect some big fish to be amongst them. Many of these late running salmon will have fed in the western half of the Atlantic Ocean, where the abundance of prey species is much better than in the Norwegian Sea. Given water, I expect there to be new fish coming into the beat right up to the last day of the season on the 31st of October.

TA 26/8/2012

More rain, a few grilse and some thoughts on radio tracking South Esk salmon

Wednesday, August 8th, 2012

 These bulletin blogs represent news about Finavon and the South Esk, and my views as a riparian owner. They are not the views of any other organisation, nor are they designed to promote the interests of any individual or organisation other than Finavon Castle Water and factors affecting the fishery. Tony Andrews

The incessant rain of the summer continues, and our farmers are starting to worry about the forthcoming barley and wheat harvests. As far as South Esk migratory salmonids are concerned, the rains and repeated freshets have ensured that this year has been a good one for gaining access to the river.

Flats & the hills from suspension bridge

This is the view from the suspension footbridge at Red Brae upstream towards the hills. The angler is fishing the Flats in good conditions for a fish.

Radio tagging project. There is little doubt that both salmon and sea trout are well spread out throughout the catchment, evidence for which can be seen in the distribution map of Marine Scotland’s tagged fish (dated 24/7/2012). It is interesting to note that there are only 12 radio-tagged fish recorded in the South Esk catchment, out of a total number of 153 fish radio tagged in the Usan mixed stocks nets between February and the end of May. Of this total of 12 MSW salmon, one February tagged fish is still in the Brechin area, three March tagged fish are above Brechin, two of which are in the Tannadice area, two April tagged fish are lying in the Finavon and Tannadice area, and six May tagged fish spread throughout the main river, one of which has entered the Prosen. One of the May tagged fish is in the upper South Esk at Braedownie. The six fish that are described as having “returned to sea” are presumably South Esk fish that, for reasons unknown, changed their minds. It is not known whether these fish may have re-commenced feeding at sea, and therefore whether they may have rejected their transmitters (see paragraph below).

Fishing Frank's Stream

Moray Macfarlane giving advice to a visiting fisherman at Frank’s Stream

With less than 25% of the total of 153 radio tagged fish recorded by receivers in the Dee, North Esk, South Esk and Tay, it is a bit of a puzzle as to why so few fish have been recorded. Scientists involved in more than 25 years of radio tagging, especially on the Aberdeenshire Dee, tell me that the 25% figure is no surprise and tallies with their experience. There is some speculation as to whether salmon that have not ceased feeding in the sea may ‘cough up’ the little radio transmitter. The assumption behind the radio tagging method, which involves anaesthetising the fish and inserting the transmitter into its stomach, is that the atrophied stomach of a fish that has ceased feeding in preparation for its spawning migration into fresh water will not reject the transmitter. However, if the stomach is still active, as may well be the case with salmon returning to the Scottish coast in February, March and early April, when the sea and rivers are still cold and fish disposed to continue feeding, the transmitters may be ejected.

As I write this blog on the 8th of August we are still catching sea trout at Finavon, bringing the season’s total to an encouraging 128. Patience is usually rewarded, as happened with the Martyn Gregory group last week, who caught 10 sea trout and lost many more in conditions that were not ideal, the main reason being that the bulk of the 2012 sea trout run was already in the upper catchment. There really is no substitute when fishing for sea trout other than putting the hours in throughout the hours of darkness and well into the early dawn, when water levels allow.

As far as salmon are concerned 57 fish from FCW pools by early August is not too bad. Another good summer freshet is currently fining down and, if there are fish now arriving off the coast, I have no doubt that they will not find it difficult to enter the river. Reports from Ireland, Norway, Spain and France suggest that 2012 has so far been a very good year for large, well conditioned MSW fish. This trend was predicted by Jens Christian Holst, the Norwegian marine ecologist, who bases his predictions on abundance and quality of planktonic species and the wellbeing of other pelagic species such as mackerel, herring and blue whiting. He also predicted another low abundance grilse year in 2012.

So we now wait to see what the autumn will bring and whether we get the weather and water conditions to catch a few of those big autumn running fish!

16lbs salmon April 2010

Finavon salmon 16lbs

Postscript written late on 8/8/2012. I had been waiting all day for the river to drop and the water to clear. At about 1830 conditions had improved to the point where I felt it was worthwhile fishing a size 12 cascade on a silver Salar double through selected FCW pools. As I started fishing it became evident that there was a run of fish – mainly small grilse – taking place, but in amongst them there were some large MSW salmon, all fresh from the sea. I started with Red Brae which was fishing perfectly with the level just lipping the top of the lowest section of the wall. Half way down the pool there was a gentle, almost silky, draw on the line resulting in a 5lbs fresh cock grilse with a damaged red vent (RVS). Knowing that Willows would have a concentrtation of resting fish I moved upriver and by the time I had finished fishing the 40 yards of Willows – again at a perfect height – I had caught a 6lbs grilse and a beautiful fresh 16lbs cock salmon, which I weighed in the net before returning. There were many other fish showing at the Willows and further downstream, but, after a perfect evening’s fishing I decided to return home knowing that I could most likely have caught another two or three fish. I also saw some sea trout but they were all well past their best.