The Ure as been at or even below MSL since late February in the driest spring in Yorkshire for 90 years: in another week, if the forecast is right, it will be the driest for over a century. Fortunately the air temperatures haven't been excessive, so the thermal risk to parr and smolts isn't too bad, but the remaining kelts will most likely have died by now. The bigger issue is the lack of water to take the April/May smolts away to sea: the lower the water the higher the losses to predation.

 

I note that Masham Anglers have stopped fishing until further notice. Due to water conditions and quality.

 

I’m not at all surprised. I was in Masham on Thursday last week and the river was shockingly low.

 

The river is in an awful state as a result of prolonged low flows and periodic high temperatures. Meanwhile, down at the bottom of the Ouse, an impenetrable oxygen barrier of lifeless contaminated water has been in place and progressively reinforced since May: no salmon can run through it until we've had prolonged high levels. And to cap it all, Yorkshire Water have just been granted a licence by EA and OFWAT to abstract a further 60,000 tons per day from the river below Boroughbridge, further reducing the flow. Whether there will be any salmon to fish for this autumn is an open question - with a wide range of gloomy answers.

 

At least if the salmon hold up in the Humber, they don't face the same Dolphin threat to those offshore Whitby - yet.

 

The evidence isn’t solid, but it’s likely that in such a prolonged drought the majority may stand off in the open sea rather than in the Humber.
In 2017 I caught a late grilse, still showing 30% silver in September, weighing close to 6lbs and fat as a piglet, that looked like it had enjoyed a summer of scoffing sandeel pies on the Dogger Bank after its arduous journey from wherever.

 

The evidence isn’t solid, but it’s likely that in such a prolonged drought the majority may stand off in the open sea rather than in the Humber.
In 2017 I caught a late grilse, still showing 30% silver in September, weighing close to 6lbs and fat as a piglet, that looked like it had enjoyed a summer of scoffing sandeel pies on the Dogger Bank after its arduous journey from wherever.

I hope you’re right and that it applies to the whole of the Uk. September given water should be tremendous

 

I’m sure I remember reading that it was very rare for the drift nets in the North East, or Republic of Ireland to catch Salmon or Grilse with any food items in their stomachs. Atlantic Salmon seem to switch off feeding a long way before they hit the UK or Irish coast.

 

I am totally ignorant on this point. Sea trout are obviously another, completely different kettle of .....fish.

 

GK,
thanks for posting that article, very interesting. It would suggest that salmon may stop feeding some way offshore. However, there are a lot of variables in play, and we do know that a lot of salmon don't just make a straight line to their destination and often move significant distances up and down the coast before entering a river (leave aside the 10% or so of 'strayers')(see here for more on navigation). The many Scottish fixed coastal nets operated on that basis, catching stock from a variety of rivers.
Another issue is the speed of the salmon's digestive system, which is as formidable as its catch and 'swallow' mechanism, and clearly evolved to operate in tandem to fuel its explosive growth (you can't increase your body mass twentyfold in 12 months with a leisurely approach to eating or digesting). The 'swallow' mechanism is automatic: as soon as a salmon takes a prey fish onto the serrated 'tongue' it is reflexively passed into the highly elastic primary stomach. This allows a salmon to take several prey fish in a single pass through a school, then turn and repeat as often as availability dictates. The primary stomach of a 10lbs 2SW salmon can take 20+ sandeels. I haven't done dissections on sea-caught salmon, but plenty on bass, which are much slower growing but nonetheless clear their similarly capacious stomach within the space of a tide (i.e. 6 hours), with only particles and sludge remaining. On that basis the fact that the stomach is empty doesn't give is much guidance as to how long before the salmon stopped feeding.
In any event there is the question of food availability. The supply of prey isn't continuous and feeding is episodic and furious. But finding prey isn't random: if it was salmon would rapidly starve as its chance of colliding with a 50 metre blob of sprats in a 1km square of ocean is less than 0.6%. Finding prey requires a team search effort by a school of salmon, using their sensors (primarily vibration via the lateral line) in concert. Operating in this mode the chance of success rises over 25%, depending on the 'noisiness' of the prey species. So what the research may show is not necessarily that the individual salmon has lost its appetite, but rather that by travelling in a roughly straight line rather than ranging and hunting, the availability of food may have sharply declined.
There are also interesting questions on outward migration destinations and return routes. Not all salmon from a river go to the same place, which would create serious survival and evolutionary risks (see Norwegian research - some Alta fish turn left, others right). The AST's 'Lost at Sea' project appeared hooked on the notion that all Scottish salmon went to the Norwegian Basin: no doubt lots do, because the prevailing currents can lead them that way, but I doubt that it's all. In that regard I find the case of Yorkshire grilse interesting. In recent years catches have been so poor that we can't draw inferences, but in the period 2010-20 we saw enough to make some inferences. First there's the question of size: they're much bigger than their Scottish peers, in the range 3 1/2 - 6lbs. Second, there's condition: grilse are inefficient swimmers (poor mass to cross section ratio) and lose proportionately more weight in migration than salmon. Come September, plump Findhorn grilse are a rarity (I've caught far more there than anywhere else), whereas Ure grilse tend to be in fuller condition. I have no factual explanation for this. However, I sometimes wonder whether some of the Ure grilse never leave the North Sea, a strategy that would offer earlier access to food as a departing smolt and a shorter and easier return trip.

 

GK,
thanks for posting that article, very interesting. It would suggest that salmon may stop feeding some way offshore. However, there are a lot of variables in play, and we do know that a lot of salmon don't just make a straight line to their destination and often move significant distances up and down the coast before entering a river (leave aside the 10% or so of 'strayers')(see here for more on navigation). The many Scottish fixed coastal nets operated on that basis, catching stock from a variety of rivers.
Another issue is the speed of the salmon's digestive system, which is as formidable as its catch and 'swallow' mechanism, and clearly evolved to operate in tandem to fuel its explosive growth (you can't increase your body mass twentyfold in 12 months with a leisurely approach to eating or digesting). The 'swallow' mechanism is automatic: as soon as a salmon takes a prey fish onto the serrated 'tongue' it is reflexively passed into the highly elastic primary stomach. This allows a salmon to take several prey fish in a single pass through a school, then turn and repeat as often as availability dictates. The primary stomach of a 10lbs 2SW salmon can take 20+ sandeels. I haven't done dissections on sea-caught salmon, but plenty on bass, which are much slower growing but nonetheless clear their similarly capacious stomach within the space of a tide (i.e. 6 hours), with only particles and sludge remaining. On that basis the fact that the stomach is empty doesn't give is much guidance as to how long before the salmon stopped feeding.
In any event there is the question of food availability. The supply of prey isn't continuous and feeding is episodic and furious. But finding prey isn't random: if it was salmon would rapidly starve as its chance of colliding with a 50 metre blob of sprats in a 1km square of ocean is less than 0.6%. Finding prey requires a team search effort by a school of salmon, using their sensors (primarily vibration via the lateral line) in concert. Operating in this mode the chance of success rises over 25%, depending on the 'noisiness' of the prey species. So what the research may show is not necessarily that the individual salmon has lost its appetite, but rather that by travelling in a roughly straight line rather than ranging and hunting, the availability of food may have sharply declined.
There are also interesting questions on outward migration destinations and return routes. Not all salmon from a river go to the same place, which would create serious survival and evolutionary risks (see Norwegian research - some Alta fish turn left, others right). The AST's 'Lost at Sea' project appeared hooked on the notion that all Scottish salmon went to the Norwegian Basin: no doubt lots do, because the prevailing currents can lead them that way, but I doubt that it's all. In that regard I find the case of Yorkshire grilse interesting. In recent years catches have been so poor that we can't draw inferences, but in the period 2010-20 we saw enough to make some inferences. First there's the question of size: they're much bigger than their Scottish peers, in the range 3 1/2 - 6lbs. Second, there's condition: grilse are inefficient swimmers (poor mass to cross section ratio) and lose proportionately more weight in migration than salmon. Come September, plump Findhorn grilse are a rarity (I've caught far more there than anywhere else), whereas Ure grilse tend to be in fuller condition. I have no factual explanation for this. However, I sometimes wonder whether some of the Ure grilse never leave the North Sea, a strategy that would offer earlier access to food as a departing smolt and a shorter and easier return trip.

Apologies for asking a slightly pratish question, after that powerhouse of information you have provided above. Is there data that exists which shows the proportion of fish in the salmons diet, and the proportion of crustacean's ? I am not quite sure how they could collect the data to be honest (?)

The reason I ask, follows on from your point about grilse not leaving the N Sea. If Blackcaps have adapted their traditional evolutionary Spanish migration routes after a few decades of being fed sunflower seeds in the UK, I am convinced a few salmon will eventually think stuff the Atlantic. And spend a fruitful life between the Humber Bridge and Cleethorpes pier hoovering up mainly shrimp and some juveniles. Why not ?

 

Up in the northern Atlantic the salmon's diet includes prawns (which form large blobs), sprats, juvenile squid (for which they dive to impressive depths), young mackerel and herrings, capelin (a key cold water prey species) and anything else edible that they encounter. All of those species are 'noisy' and readily detected at distance. Further south the sandeel features strongly, while the prawns tend to be more dispersed and therefore less attractive.

 

Hmm - not so many crustaceans then. I will put my theory on the shelf for the time being I think. Interesting topic though.

 

Good evening. Do you think ,given the recent rises, fresh salmon will have entered the Ure system?

 

There has been lovely brown water flowing quickly through York since Saturday, sufficient to clear the dead water out below Selby, and there’s more on the way. The lifts the the upper river - up to 8 feet - have been big enough to shift all the gunge accumulated over the summer. In the hope that there are some salmon still available to run, it will take them a while to get up on account of the distances (from Spurn) - York 70 miles, Thoresby 130. We may have fish in the upper Ure by early next week.

 

And with the spate coming down today (and it's still raining) will give them more water to run on.
Roll on late next week!

 

Yes, but remember that they don't usually get over Redmire Force if the Bainbridge gauge is above 70cm. it's the usual case of not too much, nor too little, but just right!

 

I much regret to report that I fished Thoresby yesterday. First, it was apparent that no fish have yet arrived. Second, since last weekend's big spate, which has done a great job clearing out and cleaning up the river, the water has fallen away at an extraordinary rate. Yesterday was just about fishable, but I didn't even both to go out today, despite having booked a double rod slot with a guest.

Unless we get a really good dose of rain very soon - and there's little or none in the forecast - the Ure is unlikely to be worth fishing before mid-October.

It's all very sad. After a string of disasters on the Orkla (spate), Tweed (spate) and Helmsdale (drought), I had been hoping against the odds that things might finally come good on my home river. Alas, it looks like I may end the season on an unprecedented zero.

 

I’m very sorry to hear that. I had been contemplating spending the afternoon at Swinton tomorrow but not sure I’ll bother now. I’ve got a day at Bolton Hall in the middle of next month so hopefully there might be some movement by then.