Aquaculture Interactions: Shieldaig Field Station

Concerns regarding declining sea trout populations on the West Coast of Scotland in the late 1980s and early 1990s led Scottish Government to set up a long term monitoring programme on the River Shieldaig.


Between March-November 2018 and 2019, a study into sea trout (Salmo trutta) movements is going to be conducted in the area of Loch Torridon, a sea loch in the NW Highlands.

Every spring some of the trout in rivers migrate to the sea where they spend the summer before returning to freshwater to spawn in the autumn and early winter. Little is known of their movements, habitat use or feeding behaviour during this time at sea however, developing this knowledge is necessary to understand the pressures that sea trout face, and the causes of the decline in numbers of this species in recent decades.

The study will involve tagging sea trout smolts as they leave rivers in the area with small acoustic transmitters. To follow the movements of sea trout, 79 acoustic receivers will be placed in Outer Loch Torridon, Loch Shieldaig and Inner Loch Torridon and the approximate locations of these receivers are indicated in Map 1 (below).

Each location is marked by a yellow surface buoy approximately 30 cm in diameter, attached to a weighted mooring rope (just like the one pictured on the right) . An underwater buoy attached to the same line maintains the acoustic receiver in an upright position approximately 10 m below the surface.

If you spot any of these moorings we ask that you leave them undisturbed. In particular the buoys are not suitable for mooring to by boat. The buoys will be clearly marked to indicate their scientific purpose.

Torridon Acoustic Array

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