Feeding patterns

[Paul Bullinger]

When I moved up to Norfolk many years ago I was keen to fish the big rivers for bream, roach and perch and in the winter months, pike. Long story short, I had many blank days. Chatting to a local guy in my fishing club, he (politely) told me I was a numpty for trying to fish on those occasions when there was a particularly high tide, due to salt ingress upriver. Lesson learnt. It struck me that "slow" days on rivers such as the Wye could be down to higher than "normal" levels of pollution (chicken farms/human waste) putting fish off from feeding. However, there is no easy way to check pollutant levels easily (as far as I know) and I was wondering if any scientific connection has ever been made between blanking days and water quality, or is it just heresay?

 

[Terry Simner]

Ask any Severn angler about 'blank days' and foam on the water (from upstream discharges) and they'll tell you, with certainty, that there's a direct correlation.
'The Foam' is the 'Kiss of Death' to a good session.

 

[Paul Bullinger]

Ask any Severn angler about 'blank days' and foam on the water (from upstream discharges) and they'll tell you, with certainty, that there's a direct correlation.
'The Foam' is the 'Kiss of Death' to a good session.

Interesting to hear about "the foam" (sounds like the title of a Stephen King novel!) Joking aside, I guessed there is a correlation but on our rivers up here in Norfolk you can't SEE the salt, likewise if in the Wye, if the pollution is invisible to the naked eye, how would you know it's there? We all know it is, but levels must fluctuate? Just wish there was an easy way to measure it!

 

[Paul Richardson]

Peaty water on the Swale is the same for barbel, less so for chub but still makes for fishing for a bite
I have fished the Wye for 4-5 days solid dawn til dark, same stretch for 4-5 seasons. Regardless of water quality there were without question distinct feeding spells and not necessarily when you would expect them e.g. late morning, tea-time
Of course you could pick up odd fish here and there but too many times shoals have gone on the munch along the stretch with everyone, into fish simultaneously.
On stretches of the tidal Hull, you could predict when pike would feed and that was always as it was filling up/ topping out. Rarely did it fish well for predators on the turn as it dropped.
Most of the time we fish when we can and get a snap-shot and we piece together all this data and do the best we can
nothing beats getting really tuned in to the beat of the river, but it takes commitment and time

 

[Joe Winstanley]

When I moved up to Norfolk many years ago I was keen to fish the big rivers for bream, roach and perch and in the winter months, pike. Long story short, I had many blank days. Chatting to a local guy in my fishing club, he (politely) told me I was a numpty for trying to fish on those occasions when there was a particularly high tide, due to salt ingress upriver. Lesson learnt. It struck me that "slow" days on rivers such as the Wye could be down to higher than "normal" levels of pollution (chicken farms/human waste) putting fish off from feeding. However, there is no easy way to check pollutant levels easily (as far as I know) and I was wondering if any scientific connection has ever been made between blanking days and water quality, or is it just heresy?

The pollution from agriculture in the Wye is diffuse rather than point source. It's unlikely it would register in such peaks and troughs. It's a just a steady constant.

May be different with 'storm' sewage discharges though.

 

[Paul Rogers]

A thought that has been plaguing my mind for the last five seasons on the Kennet and Loddon, arises from the levels of pollution affecting the sense of smell of barbel (and all fish). IMO, If the water contains not only the pollutants, but the chemicals used to break them down in the sewage works; chemicals are used to break down the foam and clarify the water, to make it LOOK GOOD, are the fishes chemical receptors to taste affected.
Since 2018, when the smell from the Fobney sewage works at Reading became really bad most days, my fishing has crashed dived. Prior to that time, most of my fish came to simple unflavoured Luncheon meat, or during the summer caster over hemp. Since then luncheon meat has only picked up one Kennet and three loddon barbel. Caster has not worked at all !!! The few fish I have caught have come to baits with a much higher flavour level.
So, it isn't just the days the discharges are happening, it is a permanent thing. As the fish become less in number through starvation, they become harder to catch simply because there are less there.. Interestingly, on the lower beats near Reading, I am not being bothered by crayfish either. Are they dieing because of the pollution too

 

[Tim Marks]

A thought that has been plaguing my mind for the last five seasons on the Kennet and Loddon, arises from the levels of pollution affecting the sense of smell of barbel (and all fish). IMO, If the water contains not only the pollutants, but the chemicals used to break them down in the sewage works; chemicals are used to break down the foam and clarify the water, to make it LOOK GOOD, are the fishes chemical receptors to taste affected.
Since 2018, when the smell from the Fobney sewage works at Reading became really bad most days, my fishing has crashed dived. Prior to that time, most of my fish came to simple unflavoured Luncheon meat, or during the summer caster over hemp. Since then luncheon meat has only picked up one Kennet and three loddon barbel. Caster has not worked at all !!! The few fish I have caught have come to baits with a much higher flavour level.
So, it isn't just the days the discharges are happening, it is a permanent thing. As the fish become less in number through starvation, they become harder to catch simply because there are less there.. Interestingly, on the lower beats near Reading, I am not being bothered by crayfish either. Are they dieing because of the pollution too

That’s really interesting.

I could recount similar circumstantial evidence of fish ‘disappearing’ on the Thames.

Also there may be a suggestion of localised populations of certain (fish) species above sewage farms/outlets and not below……

 

[Paul Bullinger]

A thought that has been plaguing my mind for the last five seasons on the Kennet and Loddon, arises from the levels of pollution affecting the sense of smell of barbel (and all fish). IMO, If the water contains not only the pollutants, but the chemicals used to break them down in the sewage works; chemicals are used to break down the foam and clarify the water, to make it LOOK GOOD, are the fishes chemical receptors to taste affected.
Since 2018, when the smell from the Fobney sewage works at Reading became really bad most days, my fishing has crashed dived. Prior to that time, most of my fish came to simple unflavoured Luncheon meat, or during the summer caster over hemp. Since then luncheon meat has only picked up one Kennet and three loddon barbel. Caster has not worked at all !!! The few fish I have caught have come to baits with a much higher flavour level.
So, it isn't just the days the discharges are happening, it is a permanent thing. As the fish become less in number through starvation, they become harder to catch simply because there are less there.. Interestingly, on the lower beats near Reading, I am not being bothered by crayfish either. Are they dieing because of the pollution too

Hi Paul. I think that's what I was driving at with my original post. Whilst not a brilliant analogy it's like the "canary in the cage" once used by miners to detect fatal levels of gas? Are barbel put off feeding due to their senses picking up something not quite right in their watery home? Despite Man's so called "brilliance" at solving problems (most of which we created!) I still think Mother Nature can show us a thing ot two. Perhaps slow days on our rivers are a sign that the water has high levels of chemicals/pollutants at that particular time and location?

 

[Paul Rogers]

I am pasting in an abstract of a paper I read on sewage disposal, you may find it interesting and show what we are up against in what is affecting the fishes ability to find/ taste their food in our rivers.
Wastewater treatment chemicals – what, why and when?

Overview

All industries have a responsibility to ensure that their trade effluent meets local, regional and national regulatory requirements. In most countries, a company’s trade effluent consent (their licence to put wastewater into a sewer, lake, river or other outsource) will be dependent on the composition of the wastewater adhering to specific criteria.

These conditions will vary greatly between countries and industries, but generally cover the temperature, pH, FOG (fat, oil and grease) content, COD (chemical oxygen demand), proportion of suspended solids and the levels of sulphates, heavy metals and other industry-specific chemicals in the effluent.

Many regulatory authorities also specify how often wastewater must be tested, as well as the methods used, performing regular audits and spot checks to ensure compliance. Failure to comply with the terms of a licence could result in it being revoked, completely preventing the business from operating but, more commonly, will result in financial penalties.

Though obviously less detrimental to a business that a complete shutdown, these fines can have a significant impact on the company's bottom line. Careful management of wastewater treatment is therefore essential to keep costs and fines to a minimum.

Wastewater treatment chemicals – the basics



Wastewater treatment chemicals – the basics


The four main types of chemicals used in wastewater treatment are pH neutralisers, anti-foaming agents, coagulants and flocculants.

The most straightforward class of chemicals is pH neutralisers, although why and how they are used varies depending on the process producing the wastewater. Essentially, wastewater effluent flowing into the sewer system should be neither too acidic nor too basic (ideally completely neutral at pH 7), as this will help to prevent undesirable chemical reactions when the wastewater mixes with other effluent. pH neutralisation is even more important if the wastewater outlets directly into a lake or river, as changing the localised pH can harm wildlife and cause knock-on issues for the local ecosystem. Unfortunately, many industrial and manufacturing processes rely on acidic or basic chemicals – from acid etching of metal parts to the use of bleach to wash down food production facilities – which are then flushed to the drain. In addition, pH adjustment (usually from acidic to basic) can be used in post-process water treatment as a way of precipitating out dissolved contaminants, such as heavy metals and toxic metals, which then need to be neutralised before outflow. Addition of small, carefully controlled doses of a strongly acidic or, more commonly, basic compounds (such as sodium hydroxide (NaOH))

(during wastewater processing is a simple way of ensuring that the pH of the effluent outflow to the sewer is within the stated guidelines).



The next category of wastewater treatment chemicals is anti-foaming agents. Foam is caused by the formation of air bubbles within the wastewater, and can be highly problematic for a wide range of industrial processes. By changing the physical properties of the fluid, foams can increase mechanical wear on pumping systems and cause drainage problems by blocking sieves and filters, reducing water processing efficiency. Foams can also cause deposits to form in storage tanks and processing vessels – increasing cleaning requirements – and lead to health risks through the promotion of bacterial growth. In addition, foams can be unsightly and cause public image issues for a business locally.

There are a wide range of anti-foaming agents available – including insoluble oils, silicones, alcohols, stearates and glycols – but they are all essentially low viscosity chemicals that cause the air bubbles to rupture and the breakdown of surface foam. Many water treatment chemical suppliers consider anti-foaming agents to be a straightforward class of chemical, but selecting the correct agent and dosing regime can have a significant impact on the efficiency of water treatment plants and ongoing operational expenses, in terms of both chemical consumption and higher maintenance costs. – Done for cost!!!!!

The last two major categories of water treatment chemicals are coagulants and flocculants, which work in combination to remove suspended solids and clarify wastewater. Coagulants are ionically charged (usually positively charged), low molecular weight compounds that are designed to neutralise the charge of suspended particles. They can be inorganic – such as aluminium- or iron-based compounds – or organic polymers, and counteract the 'repulsive' effect that stops the negatively particles from aggregating.

High molecular weight flocculants are then used to bind together these charge-neutralised particles into larger aggregations – known as flocs – to speed up the water clarification. There are a huge number of coagulants and flocculants available, and the optimal combination will be highly dependent on the composition of the effluent flow and the design of the water treatment plant. Most wastewater treatment facilities that use chemical treatment strategies to remove suspended solids rely on either settlement or floatation. The exact design of the plant should be carefully matched to the nature of the effluent but, in general terms, settlement strategies are used for the removal of heavy solids – common in manufacturing industries – whereas floatation is better suited to the removal of fats and oils, for example in food processing applications.



The choice of coagulant and flocculant should be guided by both the way the plant operates and the type of suspended solid that requires removal, and making the right choices can have a significant impact on both profitability and regulatory compliance.

Your opinions please!!!