Mainstem sampling day 8

On Tuesday the last 7 sites in the upper Spey above Spey Dam were surveyed. The results were interesting with no salmon fry found at any of the sites although there were reasonable numbers of parr. All of these sites had been surveyed in 2012 when the mean number of fry per site was 13. Missing year classes in a site or over a large area such as the upper Spey provide strong evidence that there is a pressure affecting the salmon population.

The situation for parr was different. Last year the mean number of parr in the sites was 2, this year it was 7. The majority of these parr were one year olds due to what our historic data showed to be a good spawning year above Spey Dam last year. With salmon fry only found at 2 out of 10 sites surveyed upstream of Spey Dam (both of these sites were close to each other and towards the lower end of the accessible area) it is almost certain that the parr population in the Spey above Spey Dam will collapse next year.

With high numbers of salmon fry up as far as Spey Dam the evidence highlighting the impact of Spey Dam on the migratory fish population in the upper Spey is strong.

When the Spey Dam fish counter data from Rio Tinto becomes available it will be very interesting to compare the counts with the results of our fry surveys, especially once we have a couple more years data filed.

 

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.