Swinging a fly for salmon (Photo provided by Duncan Pepper)

The following is a blog by our fantastic guest Duncan Pepper, founder and operator of Fishinguide UK and very keen angler of Scotland’s fish, particularly trout, salmon and Pike.

Duncan has set up his own business based around fishing tours in Scotland, and so has a personal connection to the way beavers have adapted our aquatic landscapes.

Follow below as Duncan explains what it’s been like to fish alongside Scotland’s newest ecosystem engineer!

“When I first heard that beaver were establishing a population on a tributary of the Tay I thought ‘this is the last thing salmon need, another hurdle in their path to survival’. That was over a decade ago and I’ve done a lot of research and had lots of personal experience to change my mind in the interim.

 I grew up on a farm a mile from the river Tay in Perthshire. I fished the Tay, many of its tributaries, and the hill lochs of the area too. If there was water, and I could walk there and back in a day from home, I would fish it. All the walking, all the alone time and all the fishing meant the natural world was my exercise, entertainment, company and teacher. I got to know what was normal and what was out of context. I saw the plants and knew which ones would have firm footing underneath. A skill I only realised was a skill when I took others out with me, their progress was slow, and many boots were filled with water. 

I didn’t know the names of all the creatures I saw, but I knew where they could be found, what they did and to some extent how they fitted in to the greater scheme of things.

 The fishing on the Tay was good when I was wee, there were lots of sea trout and far more salmon than we have now.”

A small summer grilse (Photo provided by Duncan Pepper)

“A decade or two later, as beaver started to make their presence felt in the Tay, the main change in fishing was the abundance and average size of the resident brown trout. Both have undoubtedly increased. It’s likely that the woody structure which beaver provide has given more opportunities to shelter from floods or predators as well as increasing the aquatic invertebrate populations. There are also far more grayling now. There are of course less salmon and less sea trout. Though beaver aren’t a culprit. Both of those species migrate to sea and much of their mortality is at sea. In the 1980s 30% of the salmon that left for sea would return to the river, now it’s 3%.

I started to discover on the rivers that fishing around beaver lodges is very productive, I think this is because the lodge creates a slower flow immediately downstream and often faster water next to it, that which is unhindered by the lodge. Fish love a seam between fast and slow so they can expend minimal energy while also eating. They will hang in the slow and pick food items out of the conveyor belt of fast water. 

 My wife and I moved to Argyll in 2012 and I was challenged with finding the best waters for fishing, to continue my guiding there. I had only a little experience fishing there, mostly as a teenager, but that experience included fishing the lochs that the beaver were re-introduced to, before they had been re-introduced. Fishing the beaver lochs of Argyll before the beaver were there was only productive during a short spell of ephemera danica hatch, on Collie Bharr, usually in early July. Pickings were slim the rest of the time. Barnluasgan was a decent loch before the beaver, but I had ruled it out as a guiding venue because the local angling club had stocked non-native rainbow trout into it, and I prefer to guide for wild fish. Despite the competition from rainbow the resident browns – post beaver colonisation – kept getting bigger. Before the beaver, on both lochs a good angler might catch a few skinny brown trout. These days lots of fat trout swim around the lodges and around the edges of the wetland. Whats more so they are interested in far more flies than just the mayfly imitations and one or two others. It became a regular venue for guided trips while I was guiding in Argyll. Instead of being a loch of rare interest it soon became a favourite from March to September.”

Fishing the neck of the pool (Photo provided by Duncan Pepper)

“Every salmon angler in the world knows that salmon of all species are in decline. The finger is pointed at many culprits. Fish farms, commercial trawlers, climate change, habitat degradation, predators, pollution, dams and weirs. It’s a marvel any salmon survive their long dangerous journey from and back to a tributary half way up a hill in Scotland. They are an endangered species and they are hanging on due to their incredible plasticity. From a single batch of eggs there will be some that come back from sea after just one year (grilse), there will be some (male parr) that don’t leave the river and are able to fertilise the eggs of any returning female.  There may be some that don’t spawn the first year they come back to the river, but wait till the preceding year to spawn. All this to hedge the bets, and not have all eggs in one basket.

 So adding beaver as a possible complication to this process seems like it may just be one challenge too many, or so it seemed to me. 

 When we come to decisions we weigh up the pros and cons. The wider, more holistic and less blinkered point of view comes up with the best answer. There’s human interest as well as the intrinsic value of nature to consider. In the con camp we have a possible barrier to migration of salmon, eels and sea trout. We have flooding of farmland, felling of trees and burrowing into banks causing bank collapse. This is a lot. How could one animal possibly outweigh all these cons with pros?

 There may be a slowing in the speed of passage of a migratory fish by some dams during very low flows, but the presence of beaver means the water table is higher, meaning there’s a bigger base flow so there is more water in the river during a drought. When it comes to salmon the balance of cleaner water as a result of being filtered through dams, more refuge sites, more food, lower mortality during droughts and floods and more habitat means the scale is so far over to the pro side that some salmon having to hold up on some dams during some drought events isn’t a nearly enough of a problem to tip it the other way. Especially when we can cut notches into tricky dams or fit flow devices that allow passage.”

A beavers dam is never complete in all its complexity (Photo provided by Helen McCallin)

“The thing that struck me as I got to know more about beaver effects is that it’s not about one species of fish. Once again the pure volume of other species that benefit from beaver presence and activity far outweighs any negatives. There will be more mayflies, more caddis, more stoneflies, more chironomids, more damsels, more dragonflies, more butterflies more corixa, more frogs, more newts, more toads and more dead wood. Where there’s dead wood there’s more fungi, lichens, and a huge increase in terrestrial and aquatic invertebrate life. All of these plants, fungi and animals pave the way for still more life, fish, birds, reptiles and mammals to feed on them or live with them. There’s a snowballing effect that keeps increasing the biodiversity and potential.  It’s a much needed and significant change when the status quo clearly isn’t working. Having beaver back is quite simply the right thing to do.”

For more information from Duncan Pepper and his team you can visit the website where you will find another blog on beavers.

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