Archive for the ‘History’ Category

“Rivers In Between” The River Bervie

Sunday, September 22nd, 2013

These bulletin blogs represent news about Finavon and the South Esk, and my views as a riparian owner. While I may digress at times to write about other places, these 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

Rivers regularly in the news such as the Tay, Dee and North and South Esks, of which all except the North Esk are EU designated Special Areas of Conservation (SACs), may draw attention away from little rivers such as the Lunan, Cowie and Bervie, which have unique catchments and their own estuaries into the North Sea. It is easy to forget them. This blog is about the River Bervie and the problem it currently has with a naturally recurring impassable barrier to salmon and sea trout as it enters the North Sea.

You may wonder what the problems of the River Bervie have to do with FCW and the South Esk. If you are having such a thought, do read on!

The River Bervie.

The Bervie rises in the foothills of the Grampian Mountains and flows for about 20 miles through upland farms and forestry before entering the agricultural land of the Mearns and flowing into the North Sea at Inverbervie. While the catchment is quite small, at about 85 square miles, the river is prone to big flood events from the high ground of the Eastern Grampians, as are neighbouring rivers the North Esk, the Cowie and (on the other side of the catchment watershed) the River Feugh, a tributary of the Aberdeenshire Dee.

The estuary is located between Stonehaven and Montrose. Its neighbouring major rivers are the North Esk to the south and the Aberdeenshire Dee to the north. The Bervie has populations of Atlantic salmon, sea trout and indigenous brown trout and is fished regularly by local angling clubs. Recently the Esks Rivers and Fisheries Trust, which is responsible for habitat management of the Bervie, mounted a successful programme to eradicate a serious invasion of Japanese knotweed from the banks of the middle river.

1. View of Bervie Estuary

General view of the River Bervie estuary ,showing the shingle bar that denies access of salmon and sea trout to the river.

Yesterday, prompted by an e-mail from a concerned angler, I visited the estuary of the River Bervie in Inverbervie. The photos in this bulletin show all too clearly the problems of this little Mearns river as it enters the sea.

I have fished the Bervie for wild trout for many years, so I can vouch for the excellent habitat the river provides for migratory and indigenous wild salmonids at all stages of their freshwater growth. It is a gem of a small river!

3. Detail of obstructed access

The photo above shows in detail the problem faced by migrating salmon, grilse and sea trout attempting to access the river. Strong winds and tides have swept huge quantities of heavy shingle (cobbles with an average diameter of 2 to 3″) into an extended ‘mound’ that completely blocks access. The photo was taken at high tide.

I remember seeing salmon redds in the cobble sections of the middle river pools  during the winter months. There have been many occasions in summer months when I have caught more than a dozen small wild trout on a dry fly in its pools and riffles. The biggest wild trout I have ever caught in the river weighed less than one pound! The Bervie is a fertile and productive small river with a deceptively steep catchment gradient, and consequent high energy flood events. It is quite a dynamic river.

4. Lagoon formed by shingle dam

The photo above shows the lagoon caused by the shingle barrier at high tide preventing the river reaching the sea by percolating through the cobbles of the beach. The water is backed up to create this area of fresh water.

So salmon do get into the river, and the problems of natural estuary obstructions are nothing new. In the past bulldozers have been deployed to shift the shingle to enable passage by migrating fish to and from the river. I do not know why this hasn’t happened in 2013. No doubt generations of Bervie salmon have adjusted their run timings to enable them to make use of good levels of freshwater and high tides in the winter, spring and autumn months.

8. Shingle Beach barrier

This photo shows how the banked-up shingle of rounded cobbles and large diameter gravel causes a barrier to fish migration. The picture was taken at high tide when river water is unable to reach the sea by percolating through the shingle.

I believe that the issue is not the shingle barrier itself (although it would of course be better if it weren’t there) but that mixed stocks coastal netting in the districts of the North and South Esks is probably causing potentially serious damage to  Bervie salmon and sea trout stocks. It is the combination of that unknown level of exploitation with the effect of the estuarine barrier and low water attrition of numbers of waiting fish that should be causes for concern.

7. View of sea side of shingle

Photo of the sea side of the shingle barrier with an angler spinning at the very point where the river channel should enter the sea. While I was there I saw a number of grilse and sea trout leaping clear of the water a few feet away from the steep shingle bank.

Looking upstream towards viaduct

The photo above is the view upstream from the footbridge at the sea pool of the River Bervie. The river’s water has been backed up by the high tide, which prevents the fresh water reaching the sea by seeping through the shingle barrier.

The Marine Scotland South Esk Tracking Project confirmed in 2012 that the coastal nets at Usan, south of Montrose, are killing early running multi sea-winter salmon from a range of rivers, including the Don, Dee, North Esk, South Esk and Tay.

The small east coast rivers, of which the Bervie is one, tend to have summer and autumn runs of salmon and grilse, rather than early running spring salmon. Because the MSS S Esk project focuses on tagging spring salmon (up to 31st May) it is therefore unlikely that any salmon or grilse bound for the Bervie were tagged. However, given the spread of exploitation by the Usan fishery, it is very likely that Bervie fish are killed by the nets later in the season. In a dry year, as 2013 has been, fish arriving off the coast are reluctant or unable to enter rivers affected by low levels of flow and high water temperatures. Fish that hang around in the sea, close to river estuaries, waiting for a summer freshet are exceptionally vulnerable to predation, disease, netting and natural stresses (such as the large amount of energy required for osmo-regulation).

The situation for the Bervie is exacerbated by the naturally occurring blockage of the estuary by beach shingle. The level of risk for the Bervie’s salmon stock, caused by the inability of fish to enter the river, at the same time as natural attrition in a dry year and unknown impacts from lethal exploitation by the Usan nets, may threaten the viability of the river to produce sufficient ova to ensure natural sustainability. That surely is a serious issue that needs to be addressed soon? It is not only the South Esk that suffers unknown levels of depredation of its salmon populations. Indeed, some people might with justification argue that it is “the rivers in between” that are most threatened by continuation of mixed stocks netting.

TA 22 September 2013

 

Sea Trout River?

Monday, July 22nd, 2013

These bulletin blogs represent news about Finavon and the South Esk, and my views as a riparian owner. While I may digress at times to write about other places, these 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 South Esk

A sea trout river first, and salmon river second; Is that a fair description of the river in 2013?

Willows in June

Perfect sea trout water on the South Esk. The pool is Willows

The South Esk has a long and deserved reputation as one of Scotland’s great sea trout rivers. In the 1960s it was not unusual for the total catch of sea trout and finnock in the S. Esk District to exceed 20,000. In 1967 the catch was 37,000. Only the Ythan, Deveron and Spey came anywhere close to matching these catches. As far as we know, the South Esk continues to produce good numbers of sea trout smolts, although recent years have seen a decline – possibly from competition for redds and juvenile habitat with salmon. Whether it is this, or marine mortality, which seems more likely, the last five years have seen a severe, but not unprecedented decline in numbers of returning adult fish. Nevertheless, the South Esk remains a top sea trout river.

Seatrout shoal in Boat Pool

A shoal of sea trout in the Boat Pool on Milton Beat of FCW. July 2013

I have often been asked why the South Esk is so much more productive as a sea trout river than its close neighbour the North Esk. As always with sea trout, there is no easy answer. The river has all the habitat requirements of the sea-going version of Salmo trutta L. – the brown trout, from gravelly upper tributaries to the deep pools and dubs with their quiet, alder-overhung tails. I have seen shoals of 200 – 300 sea trout averaging two and a half pounds in the Dam Pool at Kintrockat, and similar numbers in the Boat Pool at Finavon. But the most impressive show of sea trout that I have seen anywhere is in the Garden Pool at Inshewan. Less than a decade ago this single pool produced over 350 sea trout to night-fishing rods.

Unlike the great sea trout systems of the Western Highlands – Stack, Maree, Shiel, Eilt and Na Shealagh (all now ruined by reckless expansion of salmon farms), there are few big sea trout caught on the South Esk. The century average is just over two and a quarter pounds and the biggest I have ever heard of was a twelve pound fish caught at Inshewan. Sea trout of 5lbs and heavier have never been common.

Until recently the coastal nets South of Montrose continued to take a heavy toll of the South Esk’s sea trout stocks, in May June and July each year killing 2,000 to 3,000 fish, in addition to 6,000 salmon and grilse. But now the netsmen have agreed to return their catch of sea trout alive to the sea and they say that none will be sold. You would have thought that we should see more fish in the river as a result.

For anglers visiting the South Esk in June or July to fish for its sea trout, there is a culture of night fishing. There is a group of 30 to 40 anglers who home-in on this little river to fish for sea trout through the short summer nights, and witness the heavy splashes and spreading ripples made by these mysterious fish against a sliver of light in the night sky. The South Esk is (or was) defined by its sea trout. The essence of this little river is the experience of waiting beside a tree-lined pool at dusk for the colour to drain from the landscape and for the bats to start their incessant search above the water for flying insects. The lines of alders against the sky with the dark pools at their roots, and the slow, sometimes imperceptible, draw as a sea trout takes the fly, represent aspects of an angling culture that very few rivers can sustain, and the South Esk is one of these.

My view as a manager, not as a scientist, is that in the long term there is no reason why sea trout numbers should not improve. I say this on the evidence of an increase in terms of prey species biomass around Scotland’s coast, possibly as a result of recent colder winters. This increase has been recorded by SNH and marine biologists.  It appears that there is a similar trend in Ireland, the Celtic Sea and Northern England. We cannot be certain why there should be a sudden and unexpected increase in zoo plankton, phytoplankton, sand-eels etc.

What we can say however, is that further afield in the South Norwegian Sea, things are not looking so good with a collapse in herring, blue whiting and mackerel stocks. Interactions between salmon and other species tell us a lot about population dynamics, and gives us insights for explaining the condition of individual fish. To summarise; close to Scotland’s shores there seems just now to be plenty of food, but elsewhere the situation is at best patchy. Conclusion? OK for sea trout, not so good for grilse, and OK for 2 sea-winter salmon and the odd 3 sea-winter salmon that survives.

TA 21/7/2013

 

 

Sea trout arrive in numbers

Wednesday, July 10th, 2013

These bulletin blogs represent news about Finavon and the South Esk, and my views as a riparian owner. While I may digress at times to write about other places, these 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

At last there are some good shoals of sea trout in Finavon’s pools. It is not much of a surprise to me that the main run arrived about two weeks late. A discussion with an eminent salmonids scientist at the Scone Game Fair, when he reminded me that the North Sea has taken an unusually long time to warm up after the very cold spring, convinced me that there is no need to be unduly pessimistic about South Esk sea trout – or at least no more than last year or the year before.

Copy of Flow into Craigo

The flow into Craigo Stream at the head of the Red Brae Pool. A great place for a big sea trout in the hour before dawn.

My observations of three or four of FCW’s best pools in the unhelpful light of late evening confirmed that there are two or three hundred sea trout spread among these pools, and doubtless others in pools I didn’t visit. I did notice however that the average size of the fish is smaller than normal, although there are a few fish of 3lbs + in evidence too. In general I think the level of abundance at Finavon is healthy, but nothing to shout home about, and certainly nowhere near the levels of the early 1990s.

There are also some MSW salmon in the deeper pools. By now these fish, remnants of the spring run, will be well settled into their freshwater role and probably very hard to catch. A rise in the water level might persuade an occasional fish to take a fly, but in my view they are best left alone to get on up river to spawn.

Those of us who live on the banks of rivers, observing migrations of salmon and sea trout day by day and season by season, sometimes find it difficult to separate the wood from the trees. I try to avoid too much pessimism by keeping the big picture in mind. A small blip in one annual migration, such as with our sea trout this year, is just that – a small blip. If I look at FCW catches on their own I will inevitably have a distorted picture of what is happening within the South Esk catchment and, perhaps more importantly, what is happening regionally (I like the term ‘bio-region’ which describes the coastal and marine habitats of the Scottish east coast where our sea trout feed). The health of the Atlantic Ocean, and its surrounding seas, such as the North Sea or the Celtic Sea, is the much bigger context, the importance of which we are only just starting to grasp. Avoiding pessimism and doomy prognostications of future dearths of both species is a favourite passtime of the angling community. Perhaps we need to take a wider and longer view?

Our fishing effort at FCW is extremely low at present because syndicate members and our visitors have been discouraged by the low water and absence of fish. I hope that will now change because we now have good numbers of fresh sea trout to encourage more late night stints on the water.

TA 10/7