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  1. #1
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    Default Increased Salmon Catches in Rivers - 1995 to 2013

    The Map That Changed The Salmon World?

    This map arose as a follow up to the Regional maps previously presented on SFF.

    This new map is an improvement because of the more detailed scale, however it uses a different time series (so that CPUE can be compared directly). It depicts how the individual river catchment or District has performed in the last two decades. As such it gives a more detailed view of the performance of individual rivers or Districts. Here it is:




    The EA and MSS data for the rod catch of salmon rod (RCS) of each river / District is used. The river / district 5-year average rod-catch of salmon for 1995-1999 is compared to itís 5 year average rod catch of salmon for 2009-2013. So it indicates the change over about three generations of salmon. The difference worked out as a percentage increase / decrease. The river / District catchment is then colour coded such that reds represent declining catches between the two periods, and greens show increased salmon catches in catchments.

    It updates the maps here:
    http://www.salmonfishingforum.com/fo...ead102615.html

    Which show how rod caught salmon (RCS) numbers from each of the Regions of England, Wales and Scotland had performed in the last 25 years.


    The new map shows that overall, the latest available 5-year average RCS numbers for most rivers in GB have increased compared to the 1995-99 5-year average.

    The overall values for the whole of the Scotland rod catch of salmon represents an increase of almost 25% (5ya RCS has increased from 68,524 to 85,368 fish)

    During the period England and Wales rod catches have increased by over 27% (5ya RCS has increased from 15,222 to 19,345 fish)

    Which probably means there are another 200,000 to 250,000 extra salmon running the rivers versus in the mid to late 1990s (using reasonable exploitation rates).


    Of course, weíre salmon anglers and we need a relative measure of how easy salmon are to catch. Presumably if money etc. were no object most of us would rather fish Henderside, with itís 246 fish per-rod-per-season average, than Park, with itís 58 fish per-rod-per-season average.

    So therefore we also need a measure of effort to indicate whether this overall increase (and the change in catchment performance) is actually real, or merely reflects changes in effort expended to catch salmon. The following graph shows the catch-per-unit-effort (CPUE) data for EA from 1995-2013:



    These indicate the overall trend Ė recorded CPUE in GB has increased substantially. For England and Wales, CPUE has increased from 0.066 fish caught per days fishing (1995-1999) to 0.105 fish per day in 2009-2013. The most likely reason to explain the observed increase in CPUE indicates an increase in available salmon to catch. The EA CEFAS stock assessment reports for 2013 (and previously) confirm this increase in catch-per-unit-effort of salmon.

    Scotland does not collect effort data and so no meaningful CPUE data is available, but there is no evidence that the trends are not the same as they are in England and Wales.

    So, how does this increased number of salmon indicated in the CPUE trends translate to the catchments? The following is a map of the CPUE performance of the EA rivers. As can be seen, overall CPUE has performed well since the mid 1990s. Most catchments indicate no major issue at all. Those that do have well-known anthropogenic issues.





    Summary:

    Scottish Rod Catches of Salmon increased by 25% between the 1999 and 2013 5-year averages (supported by counter increases)

    English and Welsh Rod Catches of Salmon increased by 27% between the 1999 and 2013 5-year averages (supported by counter increases)

    Scottish RCS collapses (>50% decrease) in the following Districts (ranked in order of decline): Fyne, Fleet (K), Ruell, Moidart

    English & Welsh RCS collapses (>50% decrease) in the following river catchments (ranked in order of decline):Thames, Lyfni, Piddle, Dwyryd, Lyn, Frome, Ystwyth, Atro. Thames and Piddle also show CPUE collapses.

    PS - EA catchment shapes are only approximate - GIS needs improved
    Last edited by seeking; 12-03-2015 at 08:49 AM. Reason: park/hendersyde numbers edit
    "...hooking mortality is higher than you'd expect: further evidence that as a numbers game, catch-and-release fishing isn't always as straightforward as it seems"
    John Gierach


    Fed up of debating C&R - see Hidden Content

    Unless otherwise stated, data used in any graph/figure/table are Crown copyright, used with the permission of MSS and/or EA and/or ICES. MSS / EA / ICES are not responsible for interpretation of these data by third parties

  2. #2

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    The north east section from the Spey roon to the Esks looks a tad better now.

    well not better if you ken fit a mean but it shows how it is. Rubbish.

    Ta.

  3. #3
    Join Date
    Feb 2013
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    In the shadow of Morven
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    Default

    Very intresting reading again seeking,
    I can't help but notice the entire North Coast of scotland is dark green(highest increase)
    What would you put this down to?
    Less time on the coastline so less predation?
    Clear passage for smolts to open sea?
    Kind of stabbing n the dark,
    Would be interested to hear your thoughts,
    Another couple of seasons like 2013 and 2014 and it will soon be changing a scary orange/pink on the map,
    2010 and 2011 where both bumper seasons,
    2010 is no longer in the 5 year average and 2011 will also drop out after this season, another struggle of a season will pull the 5year average down a significant amount
    I however am the eternal optimist and predicting a bumper season this season

  4. #4
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    Mar 2008
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    Paisley strathclyde.
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    Do not know about maps but I do know that my river has only a few fish compared with twenty years ago and a lot less than thirty years ago.
    When U.D.N. wiped out the salmon stocks in the sixty's [?] they recovered with in a few seasons so what is wrong.
    Bob

  5. #5
    Join Date
    Dec 2007
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    cotswolds
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    Whilst delving in the freezer looking for some sausages I foolishly tipped a cup of scalding tea over myself - no problem as on average I was comfortable.

    No disputing the numbers but as ever there are lies, damn lies and statistics.

  6. #6

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    Not sure how we will ever reconcile the fact that rods can at times exploit large proportions of small stocks yet at other times perform poorly against what appears to be good counts of fish. Using catches to indicate health of fish stocks does have its problems. There are so many factors that influence catch success.


    Sent from my iPhone using Tapatalk

  7. #7
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    Jun 2008
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    Glasgow
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    Pictures and graphs? Who said you were a one trick pony...




    Ps any reason you didn't include 2014 figures in the 5yr spread?
    Last edited by Strathglass; 28-02-2015 at 11:31 AM.

  8. #8
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    Jun 2008
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    Glasgow
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    Quote Originally Posted by tenet View Post
    Whilst delving in the freezer looking for some sausages I foolishly tipped a cup of scalding tea over myself - no problem as on average I was comfortable.

    No disputing the numbers but as ever there are lies, damn lies and statistics.
    Why would anyone keep their tea in the freezer?

  9. #9
    Join Date
    Oct 2010
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    the river
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    Quote Originally Posted by Noodles View Post
    I however am the eternal optimist and predicting a bumper season this season
    Fingers crossed you are correct noodles.
    I have no idea how things will pan out. I am more in the 'expect the worst, but hope for the best' camp.

  10. #10
    Join Date
    Dec 2007
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    cotswolds
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    2,132

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    Quote Originally Posted by Strathglass View Post
    Why would anyone keep their tea in the freezer?
    It keeps longer

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