Tay Salmon Fishing Scotland National electrofishing sampling July / August 2018

Tay Salmon Fishing Scotland National electrofishing sampling July / August 2018.

TDSFB board staff have been completing the National electrofishing sampling sites which have been issued from Marine Scotland Science (MSS). Each local salmon fisheries district has 100 designated sites from 30 are chosen annually. We have almost completed our allocation for 2018.

"A new national electrofishing programme has been developed to assess and monitor the status of juvenile Atlantic salmon in Scottish rivers using a common set of standards. The protocols have been designed to collect as much information as possible to (1) explore opportunities for assessing the status of regions and rivers (2) improve existing fish density models (3) explore alternative measures of population health (e.g. biomass) (4) ensure that the collected data can support future developments in other areas e.g. National Eel Plan and Water Framework Directive." MSS

Each site covers an area of approximately 100m2 and should provide an accurate cross section of the randomly selected habitat type. Sites are randomly selected and cover a wide range of habitats across the whole Tay District. Not all sites chosen are good salmon sites and the random method of selection allows for a much wider range of waters to be fished and it was very informative to access ares of the catchment not often surveyed.

As well as accurate recording of salmon and trout densities, freshwater eel numbers were recorded. Other species encountered were lamprey, minnow, stoneloach and flounder. A water quality sample was also taken from each site.

Some were good parr sites with plenty of large structure such as the 2 Errochty water sites below. 

Errochty water near Blair Atholl

Errochty water near Blair Atholl

The Ruchill water also has good parr habitat around Cultybraggan and upstream.

Ruchill salmon parr

The very bottom end of the Ruchill has fine gravels and is very mobile during spates. High densities of salmon fry are present here. The pic below has the fish captured from a 100m2 site.

Bucket of fry and parr from lower Ruchill water

The water of May which flows into the lower Earn at Forteviot is also a very mobile burn at the bottom end. A wide bed width in which the water course often changes. Downstream of this photo the burn had completely changed course over last 2 years. On 3 run sites which are less than 3m wide stop nets are used. In this site as well as others high densities of Stoneloach were found. The warm and low conditions this year seem the suit some species well. Flounder were also found here.

Water of May @ Forteviot on River Earn

The habitat on the Eden reflects its water course through Fife farmland with slow water and large beds of Ranunculus providing good habitat for larger fish. The salmon parr here grow to substantial proportions quickly and a 1 year old parr could be 150mm before smolting the following spring.

Eden @ Ladybank

Some sites were quite remote like this one which required a 4km paddle by kayak and 3km walk from Glencoe to access. The are no barriers to salmon access to these water and while none were captured on this trip a few miles downstream good juvenile densities are found.

A well loaded kayak perfect for navigating shallow loch Ba

We had to be resourceful with carrying the heavy kit across Rannoch moor

As the river leaves loch Laidon at the eastern end good fry densities are found

This site which is located from Spittal of Glenshee is 400m above sea level. Again reasonable densities of salmon were found with 2 age groups of parr reflecting the slower growth rates at the altitide.

Allt Ghlinn Thaitneich (Dalmunzie)

Next we are surveying sites stocked eyed ova and fry in the spring time.

Mike