Research Underway on the Tweed to Assess the Effects of Avian Predation on Stocks



In a Newsletter from the River Tweed Commission and Tweed Foundation they report that work is one going to assess the numbers of avian predators on the Tweed. In January this year a count was carried out from the junction with the Ettrick down to Berwick on Tweed. The numbers are worrying, an average of 282 gossanders and 75 cormorants have been found on the river. Considering that the Tweed upstream past Peebles, the Ettrick and Yarrow, Teviot, Whiteadder and Till are not included must be cause for concern for they are the waters where the young fish start their lives. Parr, smolts and small brown trout are particularly vulnerable to these fish eating ducks.

In the hope of establishing the composition of the predator's diet the Tweed, 3 other rivers and Marine Science Scotland are looking to cull and examine some birds. SNH however will only issue a license for goosanders on the Tweed.

Ian Gordon, a well respected Spey Ghillie, claims that an adult goosander will eat an average of 20 small fish a day. For the Tweed that works out as 2,058,600 salmonids and other species: minnows, sticklebacks and on the lower river, dace. At that rate there will be vey little left in a few years.

I have watched flocks of up to a dozen birds working pools on the Tweed and on my club water the Whiteadder. Just few years ago looking over Allanton Bridge off an evening you would see shoals of fish sipping flies. Last year, 2019, the numbers were pitifully few.

In April and May last year I walked the river most days with my dog or with my fishing rod. I saw a flock of goosanders working the pools feeding rapaciously day after day. At 20 fish a day that amounts to 240 fish a day, 14,640 fish over those two months. You don't need a phd in in maths or ecology to conclude that a river the size of the Whiteadder cannot handle this level of predation.

On a more cynical note I spoke to an angler who fishes on the Ettrick. He said that there was no problem with goosanders any more because there were no small fish left for them to eat, so they have moved on.

It is sad that time has to be wasted examining the diet of goosanders on the Tweed to ascertain what they are eating. Time and fish could be saved by Googling goosander. Top of the list is the RSPB web site which states about the goosander:

" It's love of salmon and trout brought it into conflict with fishermen. It is gregarious, forming into flocks of thousands in some parts of Europe."

https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/goosander#7ULK6yPM0ZADsA6y.99

Despite the above the Tweed Commission and Foundation and many other angling bodies have to jump through hoops to prove that the presence of large numbers of these predators is disasterous. Silly isn't, when the major authority on birds admit that these birds love salmon and trout.

It is sad that at a time when numbers of juvenile fish in many feeder streams are good that their fate could be sealed when they migtrate to the main river. There is a picture on the Newsletter showing a flock of 36 birds working in convoy.

Sponsor A Fish Tag


A previous tracking study found that in 2010 81% of the fish tagged were lost leaving 19 per 100. In 2011 56% were lost leaving just 8 and bit fish. With concerns that the tagging process might have affected mortality and to improve the accuracy the Tweed Foundation is running a new tagging exercise. They will tag 50 smolts with a tiny 5mm tag which will cost £250 each. A £12,500 spend but essential at this time. They ask that anglers sponsor a tag by donating £25 (or what you can afford) towards the cost. If you have a Pay Pal account go to: Sponsor a Smolt Tag, Tweed

If they find that tags can fly we can guess who the pilot is.

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