Fishing The Fly Scotland Forum

Loxiafan

Hopefully of interest to Don Trout fishers,

About 6 months ago whilst reading “Caddisflies” by Gary Lafontaine I discovered a reference to a scientific paper about a study on Brown Trout conducted on the River Don (at Upper Parkhill !) way back before the Second World war:

“The Food and Feeding of The Brown Trout in relation to the Organic Environment” by R. M Neill, Trans. Royal Soc. Edinburgh, Vol LIX Part 2 (No.18), 1938.

It was un-available to download from the usual Web Scientific Communities but finally I tracked down a copy at Aberdeen University Special Collections and in Sept went along with the intention of photocopying it. The rather austere Librarian unfortunately wouldn’t let me photocopy it (copyright would you believe!!!!) but did let me view the journal. I was only able to make very rough notes and was limited by time – the paper is 0ver 40 pages! I filled in a photocopy requisition but sadly they wasted my time with that too as they have never got back to me !

Well, today I managed to get a full photocopy of this paper that is harder to track down than rocking horse doodoo – despite being the ‘standard text’ on the subject. I won’t say how I got it but let’s just say the Devil is a soul richer....

I have given a typed copy of my ‘rough’ handwritten notes to John Walker and he has raised this paper’s existence at the last ADAA Committee – needless to say they are very interested as the study area was the south bank above Gull (or Swan?) Island on the Upper Parkhill beat owned by ADAA.

The study was carried out in between April and July in 1931 and amongst other things it lists water quality, topography, invertebrates present and also the stomach contents of just over 70 trout (that were ‘sampled’ by fly fishing!). The main conclusions of the study were that during the study period (Apr to Jul) small Diptera, primarily Simulidae imagines (reed smuts) formed 70% of Brown Trout diet, and in July 30% of their diet was Caddis ( get yer Black Magics, black gnats, CDC Elks and Balloon Caddis oot !).

Will report more as I ‘digest’ it.

Lindsay

Mike Barrio

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #1 on: 15/12/2011 at 22:08 »
Great stuff Lindsay ..... thanks for posting :z16

Looking forward to reading what you find in it.

Best wishes
Mike

Loxiafan

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #2 on: 16/12/2011 at 13:26 »
One thing that stands out is how some of the scientific names of invertebrates has changed since then, for example March Brown is Rithrogena haarupi not germanica - the British specimens then were thought to be a separate species but were later found to be taxonomically the same as those found on the continent.

There are a few others but that is the most interesting one.

Lindsay

Sandy Nelson

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #3 on: 17/12/2011 at 12:36 »

About 6 months ago whilst reading “Caddisflies” by Gary Lafontaine I discovered a reference to a scientific paper about a study on Brown Trout conducted on the River Don (at Upper Parkhill !) way back before the Second World war:

Funnily enough, i'm reading that book just now, rather excellent with loads of nice drawings :z16 Giving lots of ideas :wink


The study was carried out in between April and July in 1931 and amongst other things it lists water quality, topography, invertebrates present and also the stomach contents of just over 70 trout (that were ‘sampled’ by fly fishing!). The main conclusions of the study were that during the study period (Apr to Jul) small Diptera, primarily Simulidae imagines (reed smuts) formed 70% of Brown Trout diet, and in July 30% of their diet was Caddis

Perhaps it is time for an updated version, but i think i'll stick to turning rocks rather than inspecting stomach contents.
So i may not create a study of what the fish are eating, but we may find out what beasties are living in the river.
I'm hoping to do photo's too, so god knows how long it will take.

Do you think i should do one beat like the original study or would it be better to try and get a cross section of the river over several beats, i know how localised some of the bugs can be, so i may need to investigate many beats, What a drag :z7

Sandy

Loxiafan

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #4 on: 17/12/2011 at 14:26 »
Hi Sandy,

Yes Lafontaine "is (or was) da man"  :z14 Scuba diving in rivers to watch the behaviour and describe the GISS of emerging caddis pupae is hardcore in my book. I guess there is taking angling seriously and there is taking angling REALLY seriously ! I got a copy of his Dry fly book, signed by the author which is especially nice given he is no longer with us.

Regarding your surveying, ideally lower river, middle river and upper river in my opinion. Parkhill already done for ADAA calendar so that is a good starting point. However, much more useful is one site over a long period of time (5 to 10 years) preferably linked to environmental data. Contrary to other opinions I have read on here the climate IS changing and one of the best indicators of this is actually insects - I say this as someone who worked for 8 years as a Marine Scientist (larval fish and macrozooplankton) and as someone who is still actively involved in biodiversity monitoring. As the mean temperatures increase there will be winners and losers. Many southern Dragonfly species are now expanding their ranges northwards - for example we now have a breeding population of Azure Damselfly here in Donside and Common Darters are prolific in East of the region whereas 10 years ago they didn't exist in any numbers (East of the Cairngorms). On the downside our Azure Hawkers in Cairngorms, an arctic species, are becoming locally extinct and are being pushed to more extremes.

The basic conclusion of Neill's study was that the trout ate what was available in proportion to what was available and when.

Cheers'

Lindsay

Sandy Nelson

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #5 on: 18/12/2011 at 00:14 »
Lindsay...the man in the know :wink

Fancy giving me a hand? sounds like you might have a lot of useful advice, bearing in mind i am no more than an amateur who happens to have a healthy interest in both what the beasties look like and where they live, as well as a desire to take their picture :z7
I've always been obsessed with things that fly and swim and i've been turning rocks with great interest since i was old enough to  pick things up, but i may prove to be not very scientific :z6 might be good to have someone to bounce things off :z16

What i have been trying to find is more info on what the bugs i find are likely to be, i have goddards waterside guide and that does give me a good start,but there seems to be a dearth of general UK entomology books aimed at average joe, unlike stateside where there are several good tomes to cover most of the invertebrates, sometimes even specific water courses.

I do like Lafontaine's book a lot, (i have not read the dryfly one) i also have the Swisher and richards "selective trout" book
which encourages you to go plodging and learn more. Any other suggestions i should perhaps be looking for?

Cheers

Sandy

Mike Barrio

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #6 on: 18/12/2011 at 11:05 »
This sounds like a great project guys :z14

Cheers
Mike

Sandy Nelson

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #7 on: 18/12/2011 at 12:12 »
It does :z16

it should take a wee while too... keep me out of trouble for a bit :wink.

Pictures and drawings along with some info, aimed more towards the angler than the scientist, could turn out to be a quite a project. If anyone else fancies contributing as well, then just drop me a PM. I know a few of you find this stuff as interesting as I do. There are some good photos of flies already on the forum, so any additional input is always appreciated.
Plus observations as well.

Don't expect fast results though, i can see it being a couple of years in the making. Now to go find out where i can get a proper seine net from :z16

Sandy

Loxiafan

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #8 on: 18/12/2011 at 17:39 »
Lindsay...the man in the know :wink

Fancy giving me a hand? sounds like you might have a lot of useful advice, bearing in mind i am no more than an amateur who happens to have a healthy interest in both what the beasties look like and where they live, as well as a desire to take their picture :z7

I don't know about being the man in the know, I'd say you know way more !  :z7 My expertise is actually birds, primarily crossbills, and at that on an amatuer basis, though regarded as an authority by some... and perhaps not by others ! However, I do know about monitoring and how to set up a valid study so I am definitely happy to put some time in - I think it is excellent that particularly trout anglers take an interest in the biodiversity in their rivers and aren't obssesed with simply how many salmon they caught this year !

It seems to be something the guys down in England are big on - Stuart Crofts was trying to collate invertebrate data and guys like North Country Angler and Rob Smith sample their rivers as part of a big project. Perhaps we can set up a River Don Invertebrate Group and split the river in to several survey points ? One of these survey points should be the Upper parkhill beat ala Neill as we can compare that directly with data from 1931 and see how much, or not, has changed since then - that is a real opportunity. There should probably be a point below this too to take in to account any effect the Airport and Paper Mills/Industry has on the river.

Although having a scientific approach is more desirable ( as you can 'measure' and create 'numbers' that can be compared across years) qualitatitive data is also useful eg. roving records of what species are present and when. Kick sampling the river would produce 'samples' that can be ID'd and counted but it would also be useful to collect pH, water heights (from SEPA data), temperature (air and water) and nitrates and phosphates (though we would need a fancyish sensor for this). We can maybe get meteorogical data (rainfall, temp) from Aberdeen Airport if we speak nicely to them. Butterfly Net sampling of flying adult specimens would also be useful as some species may not be picked up in kick sampling.

Re the guides I recently got the booklets by Field Studies Council and they are pretty good for the taxonomy and can be taken easily in to the field. Ben D sells them at Orvis Banchory (where I got mine - if you are reading Ben please set me aside the one on Stoneflies as it's the only one I need and will be in later this week !).

This is all just off the top of my head, I'll have a bit more of a think about it. Anyone interested in participating should perhaps register their interest on this thread meantime and we can see how many survey points we can have ?

Cheers,

Lindsay

PS Stuart Crofts sells some kit for doing the sampling.

Sandy Nelson

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #9 on: 18/12/2011 at 22:55 »
Cheers Lindsay

I spoke to Stuart a few years ago and helped out with a study on March browns, he was doing.
I still have some kit form then. I wasn't much use to him as i got very little time on the river that year, but next year that should be very different.
Butterfly nets i have been looking at and have an insect holding pen coming from ebay apparently it was used to house a praying mantis that has now passed on. It looks like a great way to store flies caught while out on the river to take home to photo. :grin Kick nets is what i have been trying to work out, plenty dipping nets about but only a handful of things a sensible size. I remember Ollie Edwards doing this in a video and he was using net curtains, so i might just make my own one :z16

Doing kick samples is high on my to do list as any excuse to get into the river will not be passed up.
Daniel has expressed an interest in heading in the direction of marine biology, so i intend to get him out doing some of the work too. I'm happy doing the pictures and drawings and plodging about catching beasties, so i want him to try and do the chemistry bits, to make a record. Not sure whether i need that much info though :z8 As said previously i'm no scentist and don't want to be creating a sceintific report. What i had in mind was more a reference guide for the River and its inhabitants that anglers would find useful as well as interesting.
LOTS of pictures with info on where in the river certain beasties live and how to identify them, with maybe a size guide and a timing guide (both time of day and time of year), you know something that might help you work out what is hatching so you stand a better chance of matching it.

I've ordered the books from the FSC so that should help, thanks for the pointer, i'd forgotten about them, even though i looked at that site a while ago following a link from the WTT :roll Dopey!

Going to be interesting to see where it goes :z8

Sandy

Loxiafan

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #10 on: 19/12/2011 at 00:34 »
Daniel has expressed an interest in heading in the direction of marine biology, so i intend to get him out doing some of the work too. I'm happy doing the pictures and drawings and plodging about catching beasties, so i want him to try and do the chemistry bits, to make a record. Not sure whether i need that much info though :z8 As said previously i'm no scentist and don't want to be creating a sceintific report. What i had in mind was more a reference guide for the River and its inhabitants that anglers would find useful as well as interesting.

Hi Sandy,

Yes a general study showing 'what is where and when' would be welcome and I am sure go down very well with the anglers, and who knows in the process you might discover an interesting species along the way. I'd certainly be interested in being involved. However, if anyone else is interested in doing more routine surveys I really think this would be useful in monitoring the biodiversity of our river over time. For example, through invertebrate surveying it has been noted that in some of the Yorkshire rivers recently Caddis numbers have dropped markedly - if that continues it could have serious impact on wild trout stocks.

Taff Price's "The Anglers Sedge" has some useful tips on ID and also macro photography of Caddis.

Cheers,

Lindsay

Irvine Ross

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #11 on: 19/12/2011 at 11:32 »
Sandy

I suggest the first person you should speak to is is Jamie Urquhart, the River Don Trust biologist. It might save you duplicating work he has already done. Also anything you propose to do would be of value to his work. I am sure he could give you a lot of valuable advice.

I should have a bit more time available on the river this coming season so I am willing to help out where I can.

Irvine

nochtyman

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #12 on: 20/12/2011 at 15:21 »
Sandy/Lindsay
Before going on to the river could you please phone Mr Jamie Urquhart River Don Trust Biologist on 07860846999 or 01330 830080. he can advise on the best time of year this practice should be carried out. At this time of year there are salmon and trout eggs under the gravel and it is illegal to disturb these spawning beds, which you would do kick sampling so please give Jamie a call.

Jim Kerr
River Superintendent
The Don District Salmon Fishery Board

Iain Goolager

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #13 on: 20/12/2011 at 15:37 »
Hi Jim,

Good point as you never know who is reading posts & possibly misconstrue their actual intentions.


I think there is no issue in this instance due to the blokes being well conversant with Salmo & Timmy's spawning arrangements.

Iain

Sandy Nelson

Re: Brown Trout Study, River Don Upper Parkhill from 1931
« Reply #14 on: 20/12/2011 at 16:12 »
Hi Jim

Nice to see you on here :z16
Thanks for that, i wasn't planning on starting anything until April anyway for those very reasons :z18
But as Iain says your comments are more than welcome.

I was going to speak to Jamie to see what sort of research he has done into the invertebrates, in the new year, because i realise as Irvine pointed out, he may well be a grand source of information and there is no point in covering similar ground, also i may be able to help him out with anything he may not have had a chance to do yet.

My other thing so far, is i'm not sure how easy identifying the likes of Caddis and Ephemera from the nymphs is going to be, so i reckon catching the adults after they hatch is going to be a better way of identifying the species that inhabit the river, then i can link to existing references to identify what the nymphs are going to look like and where they might live. Sounds like a cop out :oops but it seems far more practical to me, after all, a cased caddis looks much like another cased caddis yet there could be many species all grouped together and i don't want to be killing anything just to find out who lives in the house :z10

I think catching the adults after they hatch will also help me identify when they are going to hatch, so i can use the timing information in any guide, this is going to be more use to most people than lots of pictures of different cased caddis or stone clingers/agile darters. Keeping it simple and unobtrusive is very high in my priorities. Besides a folding butterfly net will fit in my tackle bag better than all the gear for kick netting (and i do still intend to catch some fish :wink)
I'm sure a couple of kick netting expeditions will be good just to get a feel for the gammarus and other bottom dewellers, but its not something i think i'll be doing a lot and certainley not until the summer time :z16

Its a plan that is evolving the more thinking about it i do, so i welcome all input and any other suggestions that people may have.

Cheers

Sandy

 




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