All

A theory for you.

I fish the Dove at Dovedale which is the upper reaches of this river.

It is stocked by the club with brown trout in the season - these are blue spot marked for members that want to take fish. There is also a good head of grayling and wild trout in the river.

During the summer months I would say that one in every six fish you catch is blue spot marked (Although some of the non marked fish are probably stockies from other clubs waters above and below).

However over Xmas I have been up to the Dale fishing for grayling. Whilst doing this I have caught some trout (I know I shouldn't and all that).

The strange thing is is that nearly all of them are spot marked. So my question is where are the wild fish that I was catching in the summer? Some are there but not in the numbers they were.

My theory (developed whist fishing on Monday) is just as sea trout go down stream to the sea, trout in the fast flowing easily flooded upper parts of rivers go downstream to calmer middle sections in the winter.

Of course the stocked trout don't know to do this and hence the higher ratio of those that I am catching at the moment.

Or is it just a higher ratio of *******s I am talking?

__________________
"The quarry is not the point of the chase, but merely its pretext, and the chase, purportedly a means to an end, is actually the end itself."Pascal 1961

This is an interesting topic.

For what it is worth, along with most other fisheries that stock on the River Monnow, my club has been dye marking our stocked fish for five seasons now. Members who want to take a fish or two are encouraged to take dye marked fish but notwithstanding this most of the dye marked fish are returned as well as the vast majority of wild fish.

We used a two mark system to monitor movement from the two stocking points for the first two seasons and then reverted to the same mark to check over-wintering. We are also fortunate to have a 90%+ member annual return rate.

The conclusions are clear. Stocked trout move both upstream and downstream during the season but more move down than up and downstream movement is further than upstream movement. Nonetheless stocked fish moved at least 2 miles upstream in the course of the season.

We have also experienced a sharp and sustained rise in the numbers of wild fish. This shot up from 22% and 25% of the total catch in the first two years to 41% in the 3rd year and has been sustained at this level for the next two years.

To come to your point, we do not record dye markings of trout caught over the winter during the grayling fishing, which is very light anyway however in the following seasons we find that less than 3% of fish bear marks from previous year's stockings, usually it is nearer 1%. There is a slight caveat to this in that dye marks are not permanent and the advice is that some will disappear into the 2nd season.

The question is where do all the dyemarked fish go at the end of the season as the one thing that is clear is that they are not in the fishery the following year and given that most fish stocked anywhere on the river in any given year bear the same mark, we are not getting our upstream neighbours' fish either so a general drop downstream doesn't seem likely.

The remaining options are:

a) The fish just don't survive the winter
b) They move upstream and stay there long enough to lose any markings if they return
c) They move downstream, possibly as far as the sea, and when and if they return they have lost their dye markings.
d) The dye markings have faded and we are catching previously stocked fish that may or may not have moved off the fishery for a while but recording them as unmarked.

In reality it is probably a combination of all four options.

I don't buy the idea that the majority of stocked trout cannot survive our much milder winters unless they die in the act of spawning or attempting to spawn.

Fish will naturally tend to head upstream to spawn at the end of the season and some may not drop back after the winter.

We know that stocked fish move downstream quite a long way in the season and they might go all the way to the sea. There is a theory that the upsurge of sea trout on the neighbouring Usk may be partly due to stocked browns dropping back and returning as slob or sea trout and the Monnow does get a sea trout run which is not characteristic of the rest of the Wye system.

Almost certainly some trout lose their marks before being caught the following season and whilst some of our members are expert enough to spot these as stocked fish, most will not and these may be falsely recorded as unmarked and therefore potentially wild fish.

We are going to progressively reduce our stocking levels over the next few seasons to see if there is a further increase in wild fish and the results will be interesting.

__________________
“There is no more lovely country than Monmouthshire in early spring. Nowhere do the larks sing quite so passionately, as if somehow inspired by the Welsh themselves. There is a blackbird on every thorn and a cock chaffinch, a twink as they call him there, on every bush...... It moved me profoundly. I had been spared to see another spring, and I thank God for it.”

Oliver Kite
“A Spring Day on the Usk”
A Fisherman’s Diary

Really quickly:

Haven't the wildies run out of your section to spawn on some suitable gravel upstream? They understand the critical depths of the correct gravel in the right places. They will also have an instinct to run upstream to counteract the downstream drift of their babies and yearlings.

The stockies have an traditional ability to spray their eggs and milt into a bucket and have lost the spawning cues and innate behaviour.

What's really cool is the way they return. I saw one fish a mile upstream on the redds, last winter. It arrived back in its summer lie with the tip of its nose obscuring the same penny sized pebble, it had done the season before.

Sorry if the chap above said the same thing and I am repeating the obvious.

Warren

So the wild fish have not left the stockies and gone downstream as I suggested but gone upstream?

If this is the case wouldn't we get wild fish from further downstream?

Alex

__________________
"The quarry is not the point of the chase, but merely its pretext, and the chase, purportedly a means to an end, is actually the end itself."Pascal 1961

If your river had spawning beds, then yes. If not the trout from below would shoot through and join yours in the head waters. Most of the trout in a river I look after, of a similar size to the Dove, spawn in water I don't manage, upstream of my responsibility. Imagine the frustration in watching the fish struggle to spawn when some gravel jetting, woody debris installation or subtle narrowing would create the perfect environment...but it's not my river.






http://141207.blogspot.com/

That makes sense Warren.

Thank you.

Alex

__________________
"The quarry is not the point of the chase, but merely its pretext, and the chase, purportedly a means to an end, is actually the end itself."Pascal 1961

The conclusions are clear. Stocked trout move both upstream and downstream during the season but more move down than up and downstream movement is further than upstream movement. Nonetheless stocked fish moved at least 2 miles upstream in the course of the season.

This is interesting - we share the downstream part of our river with another club about 1.5 miles and then have 1.5 miles of double bank. We stock evenly throughout (the other club contributes).

- However your research would suggest we should stock all fish at the bottom end of our section - whilst it seems like the other club is getting a good deal - the fish will move up to our section. In fact this answers another question - on speaking to a member of a club upstream from us he catches lots of our fish (know because they are spot marked).

To come to your point, we do not record dye markings of trout caught over the winter during the grayling fishing, which is very light anyway however in the following seasons we find that less than 3% of fish bear marks from previous year's stockings, usually it is nearer 1%. There is a slight caveat to this in that dye marks are not permanent and the advice is that some will disappear into the 2nd season.

- I agree with this our spotted fish now have a much lighter spot than they did when stocked.


The remaining options are:

a) The fish just don't survive the winter
b) They move upstream and stay there long enough to lose any markings if they return
c) They move downstream, possibly as far as the sea, and when and if they return they have lost their dye markings.
d) The dye markings have faded and we are catching previously stocked fish that may or may not have moved off the fishery for a while but recording them as unmarked.

In reality it is probably a combination of all four options.


- I would agree with this too.

Almost certainly some trout lose their marks before being caught the following season and whilst some of our members are expert enough to spot these as stocked fish, most will not and these may be falsely recorded as unmarked and therefore potentially wild fish.

- I think this would be my guess too.

We are going to progressively reduce our stocking levels over the next few seasons to see if there is a further increase in wild fish and the results will be interesting.[/QUOTE]

Good luck with the stocking lowering. I think it would be interesting to share the research - could help us both

__________________
"The quarry is not the point of the chase, but merely its pretext, and the chase, purportedly a means to an end, is actually the end itself."Pascal 1961