Things are looking up
With some settled weather recently, wandering along the river has been great for the soul!
Walking sections of both the upper and lower river, the Teign glistens like a jewel in the now seemingly serene aftermath of winter spates, its crystal-clear waters restored to a level I haven’t seen for quite some time, exposing the pristine gravel beds that lie beneath its surface.
Nature's meticulous spring clean has once again unveiled a stunning mosaic of stones and gravel, each one capturing the light and reflecting the lush environment that surrounds it.
It almost feels too good to be true when you put it like that, but I really hope these early signs point to an amazing year ahead.
Perfect gravels in the Upper Teign
I must confess to not having been out on the river to fish yet. I think it’s fair to say that the work-life balance barometer has yet to swing fully in the right direction!
That said, I have managed to get out to Fernworthy Reservoir a few times since it opened on March 15th, and it’s been a real pleasure. It’s been great to cast a line again and catch up with fellow anglers. Fernworthy is one of those spots that when you do return, you ask the question, ‘Why don’t I come here more often!?’
While it’s definitely not the same as the river, I do have a bit of a soft spot for reservoir fishing. There's something about travelling light and exploring different sections of the bank, trying to outsmart the already feeding fish. Plus, the whole setting is perfect for wildlife spotting, some quiet self-reflection, and a good walk.
Not the greatest of weather for sunbathing, but great for targeting surface feeding fish.
On a recent trip, I spent some time with a friend tuning her into the finer depths of reservoir fishing. Having grown up in the ‘Bristol Old School’ of fly fishing on the reservoirs of Blagdon and Chew Valley, I at least felt experienced in offering some advice on how to approach fishing a reservoir from the bank. After giving some of my time back, it wasn’t long before the teaching paid off and a solid resident fish was hooked, admired and released.
I’m a firm believer in offering advice to those out on the water should they want and need it. Every day is an opportunity to learn and should also be seen as an opportunity to share experience and pay things forward.
A fin-perfect resident brown trout - outwitted and returned a little wiser…
Anyway, back to the river…
With the weather remaining settled, I decided to take my own advice and walk sections of the river in the late afternoon on consecutive days. With warm sunlight on the water and relatively low wind chill, I was not surprised to see fish rising to something small. For those of you new to piscatorial behaviours, rising, or a rise, is the term used to describe when a fish reveals themselves by breaking the surface of the water when feeding.
The eagle eyed among you will spot a rising fish in this image…
Wild trout feeding behaviour on the Teign (or any river, really) is heavily influenced by environmental factors like water temperature, water flow, and the availability of food. Seeing fish rise on my recent walk was a sign of things to come and evidence that the fish are still there and looking up to feed.
Trout, like us during a busy day, are opportunistic feeders, meaning they will adapt to what is most abundant in the water at any given time. Unlike my love for IPA and pickled eggs (also known as pub Tapas!), those of you reading who contribute to our Riverfly surveys will know that their diet primarily consists of:
Insects (both aquatic and terrestrial) - Olives, caddis flies, and stoneflies are common aquatic insects, while terrestrial insects like craneflies, beetles or ants fall into the water and are frequently eaten.
Small fish - Brown trout above a certain size - Think the apex predator in a pool, will also eat smaller fish.
Crustaceans and worms - Trout will also feed on crustaceans such as freshwater shrimp (gammarus) or worms.
The way trout feed can be broken down into two main categories - Surface Feeding and Subsurface Feeding. So let's explore the differences…
Surface Feeding
Surface feeding is when trout feed on insects or other food items that are floating on the water's surface or trapped within it (these are known as emergers!). The most common surface feeding usually occurs in the warmer months, when there’s an abundance of aquatic insects like olives, midges, and caddisflies. However, these Dartmoor wild fish are opportunistic, hungry and wanting to feed.
Characteristics of Surface Feeding:
Behaviour - Trout rise to the surface to take insects or other food items that are hatching, emerging, or being blown onto the water. The fish can be seen "sipping" the food or taking larger gulps when they eat.
A Gulping Wild Brown Trout surface feeding. Totally fixated on the food item - © Henrietta Buxton
Insect Activity - Surface feeding is typically most active when insects are hatching or when there is a large abundance of terrestrial insects falling into the water. You may see lots of rising fish during a hatch, which is a sign the trout are actively feeding. A hatch can be brought on by temperature, humidity, or light conditions. Some insects, such as the heralded Blue Winged Olive tend to hatch during light rain and overcast conditions. An amazing sight - Blue Winged Olive hatches are also good indicators of river health. I’ve had the pleasure of sitting and watching full-blown hatches of Blue Winged Olives occur high on the North Teign below Teignhead and beneath the Prison at Princetown on the Blackabrook. An amazing sight. Never long in duration, but prolific in numbers if the conditions are right and the fish quickly tune into this pop-up buffet!
No, these aren’t specs of dirt on your screen… A trio of Blue Winged Olives hatching high on the Moor!
Water Conditions: Calm, slow-moving stretches of water (like pools or deep glides) are ideal for surface feeding. The surface film of the water tends to catch any insects trying to hatch, and this temporarily traps them for a hungry trout to ambush! However, trout holding in faster, more oxygenated water will snatch at any insects drowned in the more turbulent water.
Methods - We fly fishers will use dry flies to mimic these surface insects. Fly fishing techniques like upstream dry fly fishing (casting upstream and letting the water drift the fly naturally back towards you) are very effective when trout are feeding on the surface. A Dry Fly is something that floats on the top of the water, imitating an actual insect. Hopefully, from this description, it’s pretty easy to work out what a Wet Fly is!
A selection of dry flies ready for the river!
Subsurface Feeding
Subsurface feeding occurs when trout feed below the water's surface, typically on free swimming emerging insects (nymphs), or crustaceans (gammarus). Some common figures bounded around in fishing circles are that 80% of a trout’s feeding happens below the surface. With no visible rise form to see on the top of the water, giving away a trout’s location, it’s difficult to know where and how to fish!
In these instances, just ‘think like a fish!’
Trout that are subsurface feeding will often hover near the riverbed or close to structures like rocks or woody debris, looking for food.
The Teign is strewn with large granite boulders that enable trout to take refuge. By holding behind structures like these, they can take station in the river without expelling vast amounts of energy swimming against the current. If something tasty should float past, then boom, out they pop to intercept it! This is true whether it’s an actual insect or an artificial fly!
Stonefly nymph identified during a Riverfly survey - A tasty mouthful for a hungry trout!
Characteristics of Subsurface Feeding:
Behaviour - Trout in subsurface feeding mode are not visible from the surface, as they are either feeding close to the bottom or just beneath the surface. If you are lucky enough to spot a fish holding in the current, do stay and watch it for a while. A sub-surface feeding fish will move left or right to feed on food drifting by. In this instance, they are often feeding on nymphs (the immature form of aquatic insects). If you watch closely enough without spooking a fish away by moving suddenly or being too visible against the horizon, you may see the white of their mouth as they open wide to swallow a nymph down!
Food Sources - The majority of a trout's natural diet when feeding sub-surface consists of food, such as nymphs, caddis larvae, and small crustaceans.
Methods - We fly fishers often use nymphs & wet flies to target subsurface feeding trout. Techniques like upstream nymphing or swinging wet flies downstream are typical methods used.
All nymphs - Designed to be used subsurface and just as effective on a river as on a reservoir.
Time of Year: During colder months, or when water levels are high, surface hatches tend to slow down, so trout will often feed subsurface. Trout also tend to rely on subsurface feeding when surface insects are not hatching in large numbers. Think the 80%/20% rule, although don’t forget that they are opportunistic feeders, so a well-presented dry fly may also tempt them up from the depths.
Water Depth: Subsurface feeding often happens in deeper sections of the river where there’s more food on or near the bottom. Sitting deeper in the water, normally close to structures, a trout can stay hidden and feels more confident while feeding.
River Hero Alert!
It wouldn’t be right to talk about sub-surface feeders without mentioning a River Hero who carried out a groundbreaking study right here on Dartmoor.
His name - J.M Elliott
In 1963 towards the end of an exceptionally cold winter a young man - J.M Elliott - set off to live on Dartmoor. He chose to camp close to Princetown, and was there to collect samples of water from the Wallabrook (a tributary of the East Dart) as part of his PhD.
What he discovered was to have a major impact on our understanding of the interrelationship between insect behaviour and trout feeding patterns.
Elliott anchored a fine mesh net in the Wallabrook, removed it every three hours during 24 hour periods and counted the number and types of trapped insects. He spent 18 months on Dartmoor in order to collect sufficient samples to complete his study of insect behaviour.
Elliott discovered that the numbers of insects caught in his net varied significantly during the times of day.
He called this phenomenon Invertebrate Drift.
His studies showed how Insects in the 'invertebrate drift' are free drifting in the current to relocate to better feeding grounds, avoid overcrowding or escape predators. It should also be noted that this drift does not refer to insects that are ascending to the surface prior to hatching - it is a completely separate event.
Elliott's findings generated significant research interest from freshwater ecologists, and he was awarded the Scientific Medal of the Zoological Society of London in 1980. A massive tip of the hat to you, sir!
Also, thanks to the late, great and inspirational Dr Paul Kenyon for opening my eyes to this concept and paying it forward!
A true gentleman and fine angler!
Grrr… So many heroes and seemingly so little time!
In Summary
As the days grow warmer and the river comes alive with the sounds and scents of springtime, there is a certain enchanting magic in the air that beckons us to spend more precious time by the water's edge.
Regardless of whether you fish or not, this is the perfect opportunity to pause and truly observe the subtle and intricate music of nature, particularly during the quieter hours of dawn and dusk, when fish begin to rise in search of their next meal.
With the gentle flow of current and the occasional splash of a rising fish, the thrill of observation heightens as you find an ideal vantage point to witness this captivating phenomenon unfold before your eyes!
Polaroid sunglasses become an essential companion during these memorable outings, expertly cutting through the harsh glare on the water's surface, allowing for an unobstructed view of the fish’s world below.
Observing a good fish feeding on nymphs from an upstream weed bed.
A quiet approach and sunlight on the water helps visibility even more - Smolts spotted. Always a good sign!
Hopefully, as you immerse yourself in this tranquil and rejuvenating experience, let it serve as a reminder of the importance of preserving our river habitats, ensuring that future anglers and those who simply enjoy the outdoors can also share in the joys we cherish today.