While I am not an advocate of pumping stomachs I do find a wee autopsy well worthwhile doing, even if it just on an ad hoc basis and purely for my own personal interest in trout and ecology in general. For example, I once caught a trout on a shield bug imitation on a very slow day and when I opened it up, there was only a single, fresh, cased caddis in its gut showing it had not fed in some time and that the caddis had obviously caught its eye and stirred it into a moment of feeding. Then my shield bug . . . .. This was despite the fact that there were a few species of caddis coming off and plenty of the ubiquitous black midge as well.

Other autopsies have shown the trout to be very selective, others to be very choosy. To be honest I find it all quite fascinating and it gives me a lot of food for thought (whoops, excuse the pun)!

So, I would say that its always well worthwhile having a look to see and dealing with facts, rather than your imagination, assumptions or presumptions. Obviously the fish I mentioned above could have been feeding on emerging sedge or black midge, but it wasn't, it took a single cased caddis and a then my shield bug to move it. I could have assumed it was feeding on the hatches because they were occurring at the same time as I caught it but correlation in this case did not prove any relationship whatsoever.

Guddling amongst the stones, performing an autopsy, reading, etc all help to build up a picture of what is going on - challenges your thinking and gives you some facts to go on. Not to everyone's interest, sure, but I enjoy it, as do others. Its just taking a somewhat scientific approach and testing your way along by getting your hands dirty, rather than just performing thought experiments with no validation.

Its a funny old world out there and I would just caution those of you who see no value in having a real, proper look to think about how powerful really is your knowledge and imagination? Can you really take account of all factors? Or do you mistakenly see the world as a really rather boring place where you can predict and know everything without really engaging with it? I am trained to quite a high level in ecology and my friends sometimes comment on how unmoved I appear to be by things that are "amaaaazing". But to me I shall truly be amazed by nature when it ceases to amaze or educate me in all of its wonderful perturbations, and those moments when you have to chuck all you have learnt out the window, for a wee while at least!

Just my approach,

Andy

Wow, that is a very interesting read. Thanks for posting the link. There is a lot of stuff in there, that i didn't know. It's an article well worth saving.
Seems that it might not be as dangerous to the fish as we thought, provided it done properly. The emphasis seems to be on the size of the tube relative to the size of the fish, so, for people wanting to go the throat pump route, it's seems it is important to know what size fish your throat pump can be safely used on, before causing damage.

Obviously I survey around me and take in all the information available when selecting flies and yes I do want to bag up every time I go fishing however; I do not want to bag up just by ripping a cats whicker home. I get little enjoyment from that form of fishing preferring to fish imitatively with small flies and a delicate presentation.

My question was not as to whether pumping is right or wrong, merely how to do it correctly.

Thank you to everyone who has posted constructively rather than jumping on the don't pump bandwagon.

I forgot to add that in my Quincy moment's I have found alot of thing's that you are not gonna get with a pump.

The most common item other than what I call food is stones, i have often found a couple of stones in a Trouts tummy, one fish was stuffed with them and some were so big I couldnt work out how or why they were there!

I also have found sticks, weed, berries, seagull feathers, a bit of red plastic and sand.

Food items I have found that I can identify are usually buzzers and snails, the rest is just usually a dark coloured mush of sorts but quite often the stomachs are empty.

You may find this article useful Fly Angler's OnLine "Deanna Birkholm - Ladyfisher's Article - 9798"


I carry a pump every time I go to the river and have used it probably a dozen times to great effect. I am acutely aware that the process must be done carefully and would never use it on a trout under 10". It is a useful tool, must be used with care and only if you balance the risk with the knowledge gained. I would recommend that any angler considering its use should first practice on a recently deceased fish to get used to using it correctly.

As far as I am aware I have not damaged any trout in the process any more so than I am aware of damaging any trout whilst operating C&R. Each angler must have their own code on these and any matters that effect the fish , the environment where we fish, and that includes the use of Flurocarbon, fishing for stocked trout, participating on a river that stocks trout where wild trout exist etc.

Ironically I received abuse from another angler on the use of the pump, he was reacting without any knowledge on their use , fair enough. The same angler mainly fishes downstream wets using 6x and 7x flurocabon on mainly riffles and lands very few decent trout and is a strong advocate of C&R. Off course he hasn't taken into account the 10 or 20 juvenile trout that he rips hooks out by fishing downstream or the many juvenile trout that are inevitably caught by his choice of water and methods. And as for the number of small trout that he leaves flies in whilst fishing 7x on his #7 rod.......


The fact is that once we don our waders and enter a river system we do damage, off course our presence is often the only chance of survival for many rivers so it is one big balancing act.

I use the pump to garner knowledge and it has proved its worth to me and I first researched its use to ascertain that it can be used with a high degree of safety. Were it proven that its use results in many casualties then I would cease using it. In the mean time I will continue to use it judiciously to enahance my knowledge of what my local trout are about.

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An la ag iascaireacht is an la go brea.

I was not jumping on the dont pump do pump wagon, I was questioning the need for it in regard to increasing you catch if you had already caught the fish. I manage to catch plenty without using a cats whisker and mostly on natural patterns.

I think you will find that on a forum you will find it very hard to get a straight answer to a moral raising question without getting a few opinions thrown your way. The best thing to do is take what info you feel is of use to you and ignore the rest.

Oh and to answer your question."I do not know how to use a stomach pump"

Regarding the feeding habits of trout, I have found that they will vary their selected food from one hour to another and even one minute to another so subjecting a fish to a stomach pump is just going to indicate what they were feeding on previously. I too have found surprising items when gutting fish including cigarette butts which have tainted the fish so much that I just disposed of it but would you then use a cigarette butt pattern to catch another ?

I think the term 'stomach pump' may be a little deceiving, as I am led to believe the Endosampler which is what I think Neil may have been referring is actually a device for removing the very recently taken food mainly from the trouts throat.

I have witnessed this carried out correctly and the majority of the specimens taken from the fish were still alive.

Without doubt if someone tries to carry out this procedure without understanding the correct way of doing it or if they try to undertake doing it on a fish that is under size then there has to be a chance of the fish sustaining some damage but if done correctly I would have to say (from my limited knowledge and experience) that the fish will swim away without nothing more that the discomfort of being caught and relinquishing some of its recent food.

All credit to Neil Davitt for being conscientious enough to ask the question on here and ensure that if he is going to do it then at least its the correct way.

A little further info here.
Mick.

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http://micksflyfishingdiary.blogspot.com/

Wow, this thread turned out far more interesting and informative than I could have hoped.

Thanks all.

I will continue 'endosampling' albeit with the correct technique now.

I hesitate to post because this is a hot issue with fly fishers and I am rather new here. But it is an issue with which I am well versed and which I have researched over a number of years. In all honesty, I believe it is an issue to which fishers react to emotionally and without any scientific data. I think it is very similar to fly fishers who believe that Catch and Release Fisheries need barbless hook regulations to preserve fisheries. More on that later.

When I started fly fishing, I used a stomach pump. I have found it to be an effective method of examining what the fish has taken without killing the fish. It is a good learning device and has been recommended by Dr. Carl Richards of "Selective Trout" fame.

Dr. Carl Richards wrote the chapter titled What Trout Eat in the The Complete Guide to Fishing with a Fly Rod, ISBN: 0-87165-013-4. I quote from the text, "If fish are feeding underwater, two methods can be used to discover what they are feeding on. The best way is to catch a fish (usually one dummy can be taken using an attractor, fished wet, such as a Coachman) and pump his stomach with a simple stomach pump." From the caption for the pictures, "Above, a stomach designed for trout is an effective way of discovering what the fish are feeding on without harming it."

The most important thing to do is to not use it on smaller fish. You should not have to force the tube down. A stomach pump is a misnomer. It is actually a throat pump to remove what the fish has recently taken. Also turning the fish over will disorient the fish and keep it from struggling.

To those that say you have already caught the a fish and so you know what they are feeding on has simply not seen the fly used and what the fish are actually feeding on. I've never seen a Royal Wulff or Royal Coachman hatch but they do catch fish.

Like many techniques in fly fishing, I believe using a stomach pump is what could be termed a fairness issue. Is it "fair" to sample what the trout has eaten to gain and edge in fly fishing? That is really the question that each of us has to answer.

Some fly fishers feel that nymphing is somehow unfair and some nymphers think nymphing with strike indicators is less fair than fishing without. If you don't think nymphing is "fair", don't. If you don't want to use a stomach pump, don't.

But stomach pumps are not and never will be a resource issue. They have no impact on fish populations as I will demonstrate below.

Fish survival and population density studies for a health fishery have shown that there is an average annual mortality of 30% from natural causes. That is why C & R fishing does not impact a healthy fishery despite a mortality rate of about 3-4% for released fish. I doubt the usage of stomach pumps has any population impact, because they are used on occasion, whereas the 3-4% mortality applies to every fish caught.

The greatest unnecessary killers of C & R fisheries, I believe, are poor release technique and overplaying fish. Compared to these two, stomach pumps aren't even on the radar.

I personally believe the act of catching and releasing is more harmful than the act of pumping. Of course you need to catch a fish to pump it so the effects are additive. But were we to be given the choice of having our throats sampled or having a hook put in our jaw and dragged around to the point of exhaustion, most of us would choose the pump.

I believe that properly performed, throat sampling via a stomach pump is no more injurious than a properly performed C & R. When done incorrectly it can kill but so can C & R, and I suspect that there are hundreds of fish C & R'd for every fish pumped. I pumped two fish total several years ago and that was to show a beginner what the fish were feeding on.

Gentlemen, population effects are based on numbers and there are simply not enough fish pumped to have any effect compared to C & R mortality and natural mortality.

Even the use of barbed hooks does not affect trout populations in healthy fisheries. Dr. Robert Behnke, one of the the leading trout researchers in the world, has said that many studies have shown that the mortality difference (of about 1.0%) between barbless (3.5-4%) and barbed (4-5%) does not affect trout populations given the high natural mortality of trout.

See Dr. Robert Behnke's accolades:

Robert J Behnke Endowed Chair in Coldwater Conservation | FWCB Research & Outreach

Fly Rod and Reel Magazine 2003 January - 2003 Angler of the Year: Dr. Robert Behnke

Water Center - People - Robert J. Behnke


See the references below for barbless hooks vs barbed hooks.

https://research.idfg.idaho.gov/Fish...al%20Issue.pdf

http://www.dnr.state.wi.us/org/es/sc...outHooking.pdf

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Silver Creek- "Discovery consists of seeing what everybody has seen and thinking what nobody has thought"....Szent-Gyorgy