measuring a trout

Monitoring and Research

Elctrofishing on the Allt na Caillich

Elctrofishing on the Allt na Caillich

Imageseine netting at Camas na Gaul

seine netting at Camas na Gaul

Imagesnorkel survey on the River Finnan

snorkel survey on the River Finnan

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The core aim of the Lochaber Fisheries Trust is to assist the management of the region’s freshwater fisheries. To manage something effectively we need good information and to this end we regularly monitor fish populations and aquatic environments to assess their health and identify any potential threats they face.

Accurately counting fish is a difficult task and we use a number of well-practised methods to census fish stocks. Electrofishing surveys provide good estimates of juvenile salmon and trout densities, enabling us to assess the general health of the populations and identify important nursery areas within a catchment. Analysis of rod catch data, snorkel surveys and redd counts are also used to measure the status of fish stocks. There are few permanent traps or counters on Lochaber’s rivers, but the counters on the Mucomir and Morar hydroelectric dams and the Morar screw trap provide invaluable data on fish populations.

The habitat preferences of many freshwater fish species are quite specific and river habitat surveys can identify suitable areas for spawning, juvenile and adult fish. Such surveys also pick up any problems that can be limiting fish populations such as barriers to migration, sedimentation and erosion.

There is still much we do not know about the biology of fish and factors that affect their success. The LFT is involved in targeted research that aims to answer specific questions and improve fisheries management. Much of this is carried out in collaboration with other institutions. Current projects include:

  • Genetic analysis of the population structure of salmon in Lochaber’s catchments (part of the national FASMOP project run by Marine Scotland Science and RAFTS)
  • Survey of the health and distribution of eel populations in Lochaber supported by SNH and Marine Scotland - download the Lochaber eel report
  • The health of Freshwater Pearl Mussel populations in the region, and their interactions with trout and salmon.
  • The effect of freshwater fish farm cages on the ecology of Loch Shiel - downlaod Andrew Mackey's thesis
  • The movement of sea trout post-smolts through Upper Loch Linnhe
Lochaber Fisheries Trust