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  1. #11

    Default Re: DNA ...a new era for records or the start of a big mess ...

    I remember reading not very long ago that all DNA testing was very dubious, but I cannot remember who wrote the paper which is annoying however the paper did voice serious concerns about the viability of the accuracy of DNA test results for criminal evidence and one part referred to DNA profiles being nothing like as unique as they had being suggested to be. The author stated quite clearly that when DNA was first developed this had been discovered and is still the case.

    However in so far as fish and records go are we to assume that either we kill the fish or every angler has to carry some sort of laboratory test equipment for gathering a DNA sample and will need to be trained in DNA sample testing in order to prevent contamination of whatever is taken for the needed sample. Because there will lie the main problem.
    From a spark a flame will burn

    English by birth, Cockney by the Grace of God

  2. #12

    Default Re: DNA ...a new era for records or the start of a big mess ...

    Some really good points being made here Watatoad, you don’t need to kill the fish or have a test kit with you…you just need a scale from a fish which can then be returned.

    What Phil (The bad one) says makes sense to me, that the BRFC would need to lay down some sort of guideline against which results from the test could then be applied…so that would get round someone actually having to be there when the test was done.

    However Alan makes a point I never really considered – could DNA testing actually cause a perfectly good fish NOT to be instated as the new record ? …very interesting ! I don’t know how varied DNA results can be on localized fish stocks but it does seem plausible in my mind that worst case scenario…the BRFC set their guidelines on a limited number of say Roach at one end of the country and then someone catches a Roach from a different Gene pool at the other end of the country that have sufficiently different DNA to mean that even though its still a Roach it fails the DNA test ! After all even we humans come in all shapes and sizes….

    Or have I got that all mixed up ?

    Anyway, I think Peters right that I would not expect DNA to become the only method of verification, it would be just another “tool” along with the usual ray and scale counts, independent witness and so on that would be needed.

    It would be interesting to have some sort of statement from the BRFC on this …maybe there is one and I missed it ?

  3. #13
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    Default Re: DNA ...a new era for records or the start of a big mess ...

    Could I put my side in on this, I have dealt with the BRFC andknow how it works, so maybe I could clear up a couple of things.

    On the DNA and a scale coming from another fish, well as Phil, (i think it was said) you don't know if that fish is a true Roach, Rudd, whatever.

    On the Scales, well again, youdon't know if your scales are wieghing correct or not, unless you have had your scales checked.

    As for the BRFC having scales to check against, well sorry but that is one big NO, NO. When you have your scales checked by weights and measures, it isn't just a check to the weight of your fish.

    The scales are checked all the way to the full range of your scales, ie, upto, lets say 60lb from nothing, then checked backwards.
    As scales go up in the range, your scale's may under or over weigh, by a few ounces, the higher up the range you go the greater this can get, then as you get to the top of the scale range, the scales may or may not weigh correct.

    It's the only way to check if your scales way correct, underweigh or overweigh. I have 3 sets of scales, 1 set weigh's 1 oz under, until you get to 10lb, from 10lb to 30lb it's 2 ozs under, from 30lbto 40lb, it's back to 1 oz. The other two sets both weigh correct, but year, both will get a test by weights and measure's.

    The BRFC should only look at new records for, Crucian, Rudd and Roach with a scale for DNA testing, it's the only way of being correct. At the moment there are two ways to claim for a record Roach, who stupid is that.

  4. #14

    Default Re: DNA ...a new era for records or the start of a big mess ...

    Quote Originally Posted by Ray Daywalker Clarke View Post
    Could I put my side in on this, I have dealt with the BRFC andknow how it works, so maybe I could clear up a couple of things.

    On the DNA and a scale coming from another fish, well as Phil, (i think it was said) you don't know if that fish is a true Roach, Rudd, whatever.

    On the Scales, well again, youdon't know if your scales are wieghing correct or not, unless you have had your scales checked.

    As for the BRFC having scales to check against, well sorry but that is one big NO, NO. When you have your scales checked by weights and measures, it isn't just a check to the weight of your fish.

    The scales are checked all the way to the full range of your scales, ie, upto, lets say 60lb from nothing, then checked backwards.
    As scales go up in the range, your scale's may under or over weigh, by a few ounces, the higher up the range you go the greater this can get, then as you get to the top of the scale range, the scales may or may not weigh correct.

    It's the only way to check if your scales way correct, underweigh or overweigh. I have 3 sets of scales, 1 set weigh's 1 oz under, until you get to 10lb, from 10lb to 30lb it's 2 ozs under, from 30lbto 40lb, it's back to 1 oz. The other two sets both weigh correct, but year, both will get a test by weights and measure's.

    The BRFC should only look at new records for, Crucian, Rudd and Roach with a scale for DNA testing, it's the only way of being correct. At the moment there are two ways to claim for a record Roach, who stupid is that.
    Ray, I know what you mean and, yes I agree that its not just a check of the weight of the fish and I am also aware that scales can read differently at different weights…so for example they may weigh 1oz over up to 1 pound or 1 oz light at say 10pounds. That’s why as you say for anyone to really test their scales they should be tested at a range of weights.

    My point was that a set of scales sent to 2 different weights and measures offices came back with different results. That’s why I suggested that the BRFC could keep a master set of weights (I said scales…but meant weights…) in a range of sizes that could be used to test any claimant’s scales against. The advantage would be that every record fish would always be tested against the same set of weights. The only thing the BRFC need to do is make sure they have an accurate set of weights in the first place and then keep them under lock and key !

    I agree it seems mad to have 2 different records for Roach at the moment but I see that as the BRFC's way of transitioning in DNA without just throwing out the current record. If the DNA ratified fish ever surpasses the other then I suspect it will be just 1 record from then on...DNA and nothing else.

  5. #15
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    Default Re: DNA ...a new era for records or the start of a big mess ...

    Phil,

    I wouldn't throw out the Roach record, just any future claim to have a scale for DNA testing, same for the Rudd and Crucian.

    How many of the BRFC do you train so they can use the weight's correctly ??

    I forgot you also have to have, two Independent Witness'es to and claim.

  6. #16

    Default Re: DNA ...a new era for records or the start of a big mess ...

    Yes I would agree with you that for any future claim they need a scale sample to do the DNA check. I think the current open weight for a DNA fish is 4lb exact. While the current non DNA record is what …4.4 ? …so the way I see it going is that we may for example get someone catch a 4.1 that takes the DNA record..then someone gets a 4.2…and so on until someone catches one at say 4.5, it gets DNA ratified and then we return to just one entry on the list.

    About the weights …how much training does it take ? …I assume the BRFC is made up of some pretty experienced anglers right ? …all of them pretty used to weighing fish I would have thought…

    But ok…so they setup a tripod and hang the claimants scales on that…then they stick one of the master weights of say 8oz in a plastic bag, hang it on the claimants scales hook and see what the scales read against it …..then they stick a 1lb weight in the plastic bad and see what the claimants scales read for that …then stick a 2lb weight in the bag …etc etc…repeat until you have a good profile of how the scales are weighing at a range of weights. The BRFC could decide on reasonable weight increments to test with….for smaller fish they may want to use lots of smaller weights, for bigger fish less big ones…that would be for them to decide at the start.

    As long as they always use the same weights and test in the same way each time everyone is playing on a level playing field.

    The only training would be the ability to hang a set of scales on a tripod, put a weight in a plastic bag, hang it on a hook, read the scales and then write it down..

    Or am I missing something ? …How do weights and measures offices do it ?

    Of course any scale check would still need to be accompanied by Photos, witness and so on...

  7. #17
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    Default Re: DNA ...a new era for records or the start of a big mess ...

    Quote Originally Posted by Philip View Post

    The only training would be the ability to hang a set of scales on a tripod, put a weight in a plastic bag, hang it on a hook, read the scales and then write it down..

    Or am I missing something ? …How do weights and measures offices do it ?

    Of course any scale check would still need to be accompanied by Photos, witness and so on...
    If only it was that simple, and what you have forgotten is the weigh sling, bag, whatever the angler used to weigh the fish in. That has to be ith the scales when the scales are checked.

    The scales have to be checked, from Zero upto the limit of the scales, that could be Zero to 60lb, Zero to 40lb, what ever. Once at the limit, you then have to check the weight from the Limit back down to Zero.

    Unless you check the full range of the scales, you won't know how the scales are weighing.

  8. #18

    Default Re: DNA ...a new era for records or the start of a big mess ...

    I don’t think the weigh sling makes any difference to the scale testing process does it ?
    It just means you include the weight of the weigh sling (wetted weight …I am sure you will add…) …onto the total weight of the fish when your testing.

    So for example..a hypothetical situation...imagine someone puts in a a claim for say a 9.15oz Chub. Weigh sling weighs say 1.8oz wetted…so BRFC know the total weight was 11.7oz hanging on the hook of the scales.

    They then test the scales in the predetermined weight increments up to their max weight and back down again. Lets say for augments sake a pair of 12 pound weigh masters was used to weigh the fish by the angler. They test those scales at say 8oz increments (or other increments of their choosing) .. right up to their 12 pound max and back down again.

    They find the scales are reading 1oz heavy at say 1 pound to 4 pound and 1oz light at 4 pound to 8 pound and exact at 8 pound to 12 pound. Then when they do the weights back down they find it weighs still exact at 12 down to 8 and still 1oz light from 8 to 4 but from 4 to 0 they are now weighing 2oz heavy rather than 1oz

    Now the tricky bit. I am not sure if there is a standard industry protocol for how you do this but I (as in me personally) would always err on the side of worst case scenario. In other words I would take the worst possible case which here was the scales weighing 2oz heavy from 4 down to 0 and use that as my reading. So the actual record weight of the Chub claimed at 9.15 + 1.8 wetted sling would be installed at the new record at 9.13 (11.7oz less 1.8oz for the sling less 2oz max scale error = 9.13oz)

    I don’t know what weights and measures do once they have the scale profile….in other words do they also take worst case scenario or do they just look at the error on the scales at the record weight of the fish (+ sling)…

    I know it sounds long winded but what I am trying to explain would actually be pretty easy in practice…
    Last edited by Philip; 29-06-2011 at 22:30.

  9. #19
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    Default Re: DNA ...a new era for records or the start of a big mess ...

    Quote Originally Posted by Alan Tyler View Post
    "Just because it looks like a roach doesn't mean it's a true roach."

    Which begs the question, how will we know that the library against which hopeful samples are compared, itself comprises "True" roach?

    I'm told that genetic studies of Canadian burbot can identify which catchment a fish is from; has a nationwide survey of "true" roach been carried out, to ensure that the full national gene-pool has been included?
    Or will all claims be compared to the first few fish that can be identified by dissection as "true" , even if they're all from one isolated population?

    ---------- Post added at 05:15 ---------- Previous post was at 05:14 ----------

    P.S. aren't fin-clippings (tiny) less damaging to the fish than removing scales?
    Alan first fin clipping, yes a DNA sample could be gained from them, but it's permanent and disfiguring. Whereas scales that are removed grow back and can tell you other things about the fish...Approx age, definitely how long its grown for.

    Finding true roach populations whether isolated or otherwise needn't be the problem people think. As they will all have common ancestor (a true Roach) which can be found through DNA back tracking. How that's done I'm not to certain of, but it is done. Dogs being a true descendant of the wolf, now DNA proven.

    Certain trees that were though to be hybrids now proven to be genuine original species.
    One in particular that comes to mind is what's called the Manchester Black Poplar, always thought to be a hybrid of the English native black poplar. Never believed it was a hybrid and argued with many Abourculturists for well over 20 years that it was in fact the Eng Nat Black Pop. In 2005 Dr Fiona Cooper took samples from 200 random trees in the NW and DNA tested them. Lo and behold they all tested positive as Eng Nat Black Pop.
    Gave me great pleasure sending the e-mail results to the doubters and detractor

    So it can and has been done with other species, so I see no reason why fish should be any different.

    Re Burbot and catchments I think the way that is found out is radio isotope signatures in the body tissue and probably the scales too.

  10. #20
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    Default Re: DNA ...a new era for records or the start of a big mess ...

    Had a bit of a google, Phil, and discovered there's a problem with fin-clipping in french carp fisheries, either from dealers marking their stock batches , fishery owners monitoring their stocks, or "foreign"(!) anglers marking their captures. (Funny how its always foreigners - didn't Dennis Pye find a couple of home-grown idiots punching holes in the fins of Broads perch?).
    I guess this is why you are opposed to it - (is it?), in the wrong hands it can indeed harm a fish.
    But I remember having to fin-mark crucians for a capture-recapture/Lincoln index type project (undergrad field trip), and by the end of a fortnight I was getting quite squinty, trying to figure out what was a Tyler-generated mark and what was a bit of natural damage - tiny clippings do seem to heal up.
    Tiny!
    Bear in mind that scales are within the epidermis, and their removal opens quite a wound - is this really safer than taking a lentil-sized bit off a soft ray or two?
    I suppose we also need to consider that these will be old fish, unlikely to be recaptured, so the visual effect is unlikely to upset a future captor...


    A bit more googling confirmed that the N. American burbot had been tracked back to three ice-age refugia (not catchments - thank you, beer at lunch-time!) by mitochondrial DNA.
    A chap called Vaughan Paragamian also looms large, having detected genetic differences between burbot in different reaches of one river system (Kootenai). Haven't been able to google further, preparing to actually go fishing, for a change! Lord knows what the rest of the field are up to with other species.

    As long as a wide range of "True" specimens from a wide range of waters are used to set the standards for record fish, all should be well; but the ol' "be careful what you wish for" may lurk around the corner, if it turns out that roach, rudd and bream haven't yet split sufficiently to be regarded as separate species, but races of one species - cat, pigeons, such fun!
    Last edited by Alan Tyler; 30-06-2011 at 06:58. Reason: Typos

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