Every autumn & early Winter the Tay’s hen salmon fight to dig redds. Those gravel nests should be the cradle of future stocks. But today, most gravels are clogged with silt, compacted by decades of neglect. Eggs that should be safe in 8–12 inches of clean gravel are now laid too shallow, suffocated, or washed away.
Anyone who fished the River Tay 40 or 50 years ago will remember the sight: huge, dark, dense shoals of salmon fry present in the river margins each late spring & Summer. They were so thick (often 20ft x 5ft) it was impossible to miss them. Fast forward to today, and what do we see? Thin, scarce, patchy fry shoals at best!– the living proof of what silt choked redds and unchecked predation have done to the river.
Over the last 85 years many 'major' hydro dams (78) have been constructed in Scotland for electricity production which is obviously an essential requirement for society. However, when hydro dams are constructed across a river it floods the upstream spawning beds rendering them useless through excessive depth and zero flow and also blocks the natural ability for the river to replenish the gravel beds through each high water pressure period. Once this natural gravel movement 'self replenishment' stops then over time a gradual annual ongoing reduction in optimal spawning gravel occurs. In addition to this fact the rivers have been exposed to excessive sediment displacement via commercial forestation 'grip drainage' enterprise. Once sedimentation is displaced via these large scale high ground commercial forest drainage schemes it will eventually work its way to low ground and end up finally impacting riverbeds. Imagine the millions of tonnes of sedimentation that has been displaced in the last 100 years via commercial forest drainage in the Scottish hills & glens compared to the 'negligible' amount that would have been naturally released from the Ice Age 11,500 years ago up until the beginning of the commercial forest era!
Even when depleted egg to fry numbers do hatch, they face another killer: unchecked brown trout populations. The Tay is now absolutely 'overloaded' with them. These predatory trout gorge on salmon fry, hammering recruitment in the early stages of juvenile development diminishing the chance of maturing to smolts and heading to sea. If you fish an uptream silver Toby or Rapala during late Spring on any narrow Tay channel and you'll quickly see what I mean as predatory trout migrate to these easy ambush points when our already diminished smolt run is underway. And here’s the bitter irony: the Tay Protection Order, brought in decades ago to control angling pressure, effectively stopped large-scale trout fishing. That move has inadvertently crippled juvenile salmon stocks, by allowing brown trout numbers to explode unchecked. Instead of balance, we’ve created a predator-heavy system where already diminished juvenile salmon fry, parr & smolts don’t stand a chance.
All through my childhood and into adulthood I've fished for trout with wet or sometimes even dry flies. As a boy, I used to watch the tweed clad trout fishers appear on the Tay with their wicker baskets and dry fly tactics right on time for the May fly hatches. It was genuinely mesmerising to watch their fine art. Back then in the 70's there was a good balanced head of trout in the Tay which were a pleasure to fish for on ocassion. From the 70's to today is 'chalk & cheese' as now the Tay is absolutely stuffed full of trout to the huge detriment of juvenile salmon of which the brown trout is the number 1 'in-river' predator which is a hard fact overlooked (or completely unknown) by the vast majority of river management & salmon fishers. This issue has been exaserbated due to the rapid expansion of heavily stocked trout loch fisheries all across Scotland in the last 30 years as that is where the vast majority of the trout fishers are to be found these days. This shift of general trout fishing angling pressure from river to loch fishery has compounded the numbers of wild trout in the River Tay and other Scottish rivers again to the detriment of vital juvenile salmon stocks.
So the Tay faces a two-pronged crisis: choked redds and a massive overpopulation of trout. Until those basics are fixed, talk of marine survival and climate change is just noise.
What needs to happen with immediate large scale effect is simple:
Clean and restore traditional spawning bed gravels via tried & tested siltation extraction methods so as not to just move the sedimentation issue downstream.
Actively manage brown trout numbers to protect juvenile salmon to a healthy balanced co-existence level. Relocating these fish locally for youth development angling opportunities should be explored.
Revive proper beat-level 'river husbandry' across all Scottish rivers and make available to all river keepers & ghillies a 'best practice' manual for reference regarding these proven traditional juvenile salmon stock enhancement methods.
Both of these basic traditional annual 'river husbandry' tasks are actionable via existing fishery board staff or/& by professional salmon beat ghillies and both will have an immediate positive impact that can be visually measured from doing so. In effect each Tay salmon beat could & should be viewed as an independent 'wild' salmon hatchery. Healthy redds plus balanced predation control equals strong salmon runs. Ignore these facts, and we’re only watching a slow-motion extinction.
And here’s the bit any Tay fisher will recognise: wade through a gravel bed or prod it with your wading stick and you’ll see it first-hand. A couple of inches of loose gravel on top, then nothing but compacted sediment & silt beneath (see attached video taken this week on the middle Tay). It’s plain common sense – those conditions will never hatch salmon properly and are nowhere close to the 6 - 12 inches of natural loose gravel depth a salmon redd requires for optimal protection, predatory free incubation, oxygenated water flow and maximised salmon fry yields. If you’ve fished the Tay long enough to remember those huge dense fry shoals, and if you’ve felt the dead gravel under your boots today, you already know the truth. This isn’t theory – it’s just plain fact.
What I've mentioned in this article are the 2 most significant issues affecting wild Atlantic salmon stocks on the Tay today and highly likely on many other Scottish salmon rivers too. Be the first to implement a new more 'holistic' common sense approach to salmon stock management in line with forgotten yet proven traditional 'river husbandry' techniques and lead the way by setting a positive year by year 'results based' example. It's now time for a new effective approach to river management and there should be nothing more inspiring & exciting than observing the regeneration of those massive dense 'naturally' produced salmon fry shoals in the Tay's margins once again!
