Fly Fishing Devon: Wild brown trout in Dartmoor rivers are special

This video was inspired by an article in The Independent newspaper by Andrew Brown who summed up the attraction of fishing on Dartmoor:

"To gain a sense of remoteness from the quotidian world, and closeness to primal monsters, is one of the main reasons for fishing. This is quite unrelated to the size of the quarry. It is a function of their wildness. Wild brown trout are now almost impossible to find in the south-east of England, and are little valued where they are found, compared to fat stocked fish. Dartmoor offers the last remaining accessible and affordable fishing for them in southern England."


The majority of wild brown trout caught on Dartmoor and in South Devon are less than eight inches long, but each season anglers catch larger 12 or 13 inch fish.

As guides and instructors we are often asked:
  1. Are big fish more difficult to catch than smaller fish?
  2. Are big fish 'smarter' than smaller fish?
As guides and instructors we often ask ourselves:
  1. Do skilled anglers catch more fish?
  2. Do skilled anglers catch bigger fish?

This page discusses the size of trout in Dartmoor rivers, and the expertise required for their capture. I hope it will help you appreciate our fish - of whatever size. It's our job to show you the necessary skills to catch them and explain why we treat them all with great care

Size of trout caught by anglers

This graph shows the numbers of trout of various sizes caught by anglers on a West Country river:
  1. most of the trout were less than 8 inches long
  2. relatively few trout of 10 inches or longer were caught
  3. hardly any fish of 13 inches or longer were taken
Two questions spring to mind:
  1. Why were so few big fish caught?
  2. Are bigger fish 'older and wiser' and therefore less likely to be caught by anglers?

Age of trout caught by anglers

The larger fish are certainly older.
This graph shows the growth rate of wild brown trout in our area.

  1. fish of 12 to 14 inches take six years to reach that length
  2. our trout are about three years old before they spawn for the first time
  1. consequently small fish should be carefully returned to the water so that they have an opportunty to reproduce
  2. it also helps to use barbless hooks

But, are older fish 'wiser?

Trout mortality

The older fish are certainly 'survivors'.
This graph shows that out of 1000 eggs laid by a female trout only two will survive to their  fourth birthday.

  1. mortality is especially high in the period between hatching from the egg to establishing a territory
  2. only 20 fish reach their first birthday
  • so, the next time you hear someone complain about the small size of the fish they are catching, remind them that an eight inch fish is probabaly three years old and is one of a group of maybe only six fish that remain from a clutch of 1000 eggs!

But are larger surviving fish necessarily 'smarter' and more difficult to catch than smaller younger fish?

They are better at avoiding predators. They may be more easily 'scared' by unfamiliar shadows, sights and vibrations than non-survivors. But we need to remember that fish have evolved to deal with their natural enemies, not necessarily angler's flies. Provided you can present an appropriate fly at an appropriate time and place and most importantly - do it in such a way that you do not scare the fish - there is no reason why you should not be successful.

But how do you catch the bigger fish? There is a well known saying that "10% of the anglers catch 90% of the fish". The graphs suggest that there are simply fewer bigger fish and therefore the more fish you can actually catch then the greater the chance that one of them will be big.

If you do catch a big one, treat it with the respect it deserves. After all it's one of nature's great survivors.

But don't worry if you don't catch a big fish, it really is just a matter of proportions!

Words of wisdom and experience ...

The actor Sir Michael Hordern learnt to fly fish when his parents moved to Dartmoor in 1925:  "By day I got to know the wilder moorland streams, the East Dart, Swincombe, West Dart, Cherrybrook. Wallabrook.... I developed a love of the moor that has never left me."

But in his later years he was critical of changing attitudes: "Actually catching the fish used to be of secondary interest, what really mattered being the expertise required in presenting exactly the right fly to the fish. These days an enormous amount of people have taken up fishing as a sport and all they seem to want to do is catch the biggest fish possible."

Sir Michael was under no illusions about the size of Dartmoor trout: "Dartmoor fish may be small but my God they're the best that swim."

As guides and instructors we often ask ourselves:

  1. Do skilled anglers catch more fish?
  2. Do skilled anglers catch bigger fish?

In early June 2014 Dartmoor was the venue for the Commonwealth Fly Fishing Competition(CFFC). Seventy five experienced anglers representing nine countries each fished the East or West Dartfor three hours.

The next two images show my analysis of each angler's catch based on results posted on the CFFC website.

Total catch by each angler

This diagram shows that even experienced anglers find Dartmoor challenging

Nearly a third (32%) of competitors failed to catch any fish over 6 inches long.

(Note: I assume that only fish over 150 mm (about 6 inches) were counted

A group of anglers were catching at a rate of at least one fish every 10 to 15 minutes

Largest fish caught by each angler

These results illustrate Sir Michael's point that Dartmoor rivers are home to relatively small fish

  1. But bigger fish are present
  2. Two 13 inch fish were caught 
  3. And a further 18 fish over 10 inches were taken across the three days of competition

Some final thoughts ...

The American author John Gierach has a refreshing approach to the increasing tendency to equate fishing quality with the size of the fish caught 

For example he writes " Let me introduce an idea, just something to kick around. Maybe your stature as a fly fisherman isn't determined by how big a trout you catch, but by how small a trout you can catch without being disappointed. And of course without loosing the faith that there's a bigger trout in there"

And - as this video shows - there are bigger trout in Dartmoor rivers: sea trout


  1. Frost and Brown, "The Trout", published by Collins, London 1967
  2. Watson, "The Trout: A Fisherman's Natural History", published by Swan Hill Press, Shrewsbury, 1993
  3. Michael Hordern, "A World Elsewhere", Michael O'Mara Books Ltd, 1994.
  4. Commonwealth Fly Fishing Competition website retrieved on 18/06/14
  5. John Gierach, Fly Fishing Small Streams
  6. Andrew Brown, The Independent newspaper article "Country: Dartmoor/ Wild trout in a perfect, miniature world". URL retrieved 18/6/14: