National Electrofishing Programme for Scotland (NEPS)
This project is funded by the Scottish Government, SNH and SEPA. Ordinarily Fishery boards use electrofishing to answer targeted questions. For example, can fish get above this barrier? Has there been spawning in this area? Are fish present in this area? While good for answering these specific questions, the data gathered to date is not statistically robust enough for giving an impression of juvenile salmon populations at a catchment level. This is because the electrofishing sites have not been randomly selected. The NEPS project uses a Generalized Random Tesselation Stratified (GRTS) design to select random sites which will give a more statistically robust impression of the salmon populations at a catchment level. The importance of this is that in areas of good habitat it will be difficult to detect a decline until it’s too late to do something about it, as salmon will preferentially occupy areas of good habitat than sub-optimal habitat.
Conversely when the salmon population is in a good state, the areas of good habitat will be fully occupied and therefore fish will be pushed out into more marginal areas. Marine Scotland aims to produce a review in 2019. If successful, the project will continue on with the eventual goal of this data feeding alongside the rod catch tool for conservation assessments of rivers in future years.
The Missing Salmon Project
A large project led by the Atlantic Salmon Trust and with multiple project partners, this project aims to examine the low return rates of smolts after they head out to sea. Around 5% of smolts return to their natal rivers as adult fish, and this project is using the “likely suspects” framework in order to examine why. Part of this framework involves examining the river and marine mortality of smolts. In 2019 it is hoped that smolts from the River Oykel and the River Shin will be fitted with acoustic tags. Listening devices will be placed both in river and in arrays in the Dornoch and Moray Firths. Based on where smolts “disappear” this will give an idea of where mortality of smolts is taking place. This will then direct future investigations and possible remedial action.
The latest update ( Dec 2018) on the Missing Salmon Project can be found on the website below.
Loch Shin Smolt Trapping & Transport
Due to the unique nature of Lairg Dam on Loch Shin, salmon smolts from tributaries feeding into Loch Shin have difficulty finding their way out through the dam on their way to sea. To help these fish get to sea (and hopefully come back as adults!) Kyle Fisheries and SSE run a “trap & truck” operation on these tributaries every year. Smolts are caught in either rotary screw traps or a box trap and transported down below the Shin diversion dam.
A portion of these fish are tagged with passive integrated transponder (PIT) tags. These tags do not rely on battery power so have a variety of uses. We use them for mark-recapture studies to assess trap efficiency, but also to assess how many fish are coming back to the Shin. A PIT tag decoder in the fish pass at the diversion dam allows us to detect individual tags and we can trace the tag numbers back in our records to each fish when it was tagged. This allows us to determine the salmon’s place of origin, size when caught, the date it was tagged, where it was released and if any genetic or scale samples were taken. This information enables a variety of investigations to be completed, but of particular importance it allows us to calculate the return rate of the smolts going to sea.
The Henry Morrice Project
Henry Morrice was the superintendent at the Kyle of Sutherland District Salmon Fishery Board from the 1960's to 2001. A very diligent man, he kept detailed records of the daily activities of the board. This contains information on correspondences with the government, bailiffing activities and the results from scientific investigations, some conducted in collaboration with the North of Scotland Hydro Electric Board (now SSE). This valuable information is not published, or in any formal reports. To make use of this information, Matt Curran at UHI is archiving the documents as part of his PhD project as well as then examining why information such as this isn’t utilized in scientific journals and remains “grey literature”. This will allow Kyle Fisheries to examine historical data from within our catchment and compare with how things are today, as well as examining any pieces of work which have been “lost in time”.