Conservation

The Langavat Catchment

The Grimersta fishery covers much of the greater Langavat Catchment. The headwaters rise in the glens of the North Harris mountains and flow north into East Loch Roag at Grimersta. The catchment covers an area of approximately 105 square kilometres.

The underlying geology is predominantly slow weathering undifferentiated Lewisian Gneiss with typically nutrient poor (oligotrophic) lochs.

Fish Stocks

Grimersta is best known as a Grilse fishery although there is a run of spring and summer salmon with fish of up the mid teens in weight regularly taken. Brown trout (Salmo trutta) are found throughout the system and in the many smaller adjoining lochs. Artic char (Salvelinus articus) are also present, most notably in Loch Langavat.

In common with much of the west coast, stocks of Salmon (Salmo salar) and Sea trout (Salmo trutta L.) suffered a decline with the Grimersta rod catch reaching a low point during the late 1990's. Since then, there has been a steady and encouraging recovery to the current five-year average of 393 salmon / grilse.

Nevertheless, there is much work to be done and the conservation policy at Grimersta is aimed at restoring, sustaining and improving the run of fish.

Species

Black Throated Divers

The majority of the area is characterised by rough moor land and blanket bog and is home to a variety of rare birds and plant species.

During the summer months, a day's fishing is enlivened by the presence of Red Throated Divers (Gavia stellata) and Black Throated Divers (Gavia artica) on the lochs and these can be seen travelling between the sea and freshwater.

The area is home to Golden Eagles (Aquila chrysaetos), which can be frequently observed; White Tailed or Sea Eagles (Haliacetus albicilla) are now increasingly seen in the area. The Outer Hebrides remain a stronghold for Otters (Lutra lutra) and these are frequently observed although most usually by early morning anglers on the lower river.

Sea Eagle

Designations

The catchment includes the Loch nan Eilean Valley Bog Site of Special Scientific Interest (SSSI). Much of the area is covered by the Lewis Peatlands Special Area of Conservation and Special Protection Area.

In 2005, the Langavat catchment was designated as a Special Area of Conservation for Atlantic salmon under the EU Habitats Directive.

Survey Work

The Langavat Catchment Stock Assessment Report, produced in 2001 by Senior Biologist Mark Bilsby and Dr. Helen Bilsby of the Western Isles Fisheries Trust was compiled from survey work conducted between 1998 and 2001. This provided a detailed habitat survey and led to the Langavat Management Report on which fisheries management policy is based.

Conservation Measures

Red Deer Herd

Habitat

There has been little change in land use with grazing pressure remaining much the same. There are indications that whilst sheep numbers have decreased there has been an increase in the Red deer (Cervus elaphus) population and there is localised evidence of over grazing.

Langadale River

Langadale River (Abhainn Langadail) is the principal tributary (draining an area of 10 square kilometres) and one of the key spawning areas for the catchment. Over grazing here has led to a reduction in riparian vegetation leaving substantial lengths of bank subject to severe erosion and collapse. This has caused a widening of the river channel, an unstable river bed and down stream siltation.

The North Harris Trust is undertaking a planting scheme in Glen Langadale covering an area of 34 hectares of which 13 hectares will be afforested. Native broadleaves will cover 8.5 hectares with Caledonian Scots Pine (pinus sylvestris) covering 4 hectares.

A smaller scheme between the Linsiadar Grazings and Grimersta is planned for the Eastern bank of the lower Grimersta River; further planting and habitat improvement will take place elsewhere on the system.

Mink

American Mink

American Mink (Mustela vison) are non-native and pose a particular threat to juvenile salmonids and ground nesting wild birds. Mink trapping is undertaken year round by the Grimersta staff. Scottish Natural Heritage established the Hebridean Mink Project which has successfully eradicated mink from the Uists and reduced mink numbers in South Harris. The second phase of the project will extend throughout the Outer Hebrides and should have a major impact on the survival of juvenile fish. Partners for the Hebridean Mink project include Scottish Natural Heritage (SNH), Royal Society for the Protection of Birds (RSPB), Western Isles Enterprise (WIE), and Comhairle nan Eilean Siar. The project is part funded by the Esmee Fairbairn Foundation.

Area Management Agreement

An Area Management Agreement (AMA) for Loch Roag between the aquaculture industry, wild fish interests and the Scottish Executive (now Scottish Government) was signed, witnessed by Rhona Brankin, Deputy Minister for the Environment and Rural Affairs in August 2006. This has allowed the aquaculture industry to relocate fish farm sites and to coordinate treatments and fallowing with the aim of reducing sea lice in Loch Roag which should greatly increase the chances of post-smolt survival.

Catch and Release

The Special Area of Conservation Management Plan has encouraged the various fisheries and angling clubs with an interest in the Langavat catchment to develop a voluntary agreement to ensure best management practice with the aim of reducing the exploitation of fish stocks. This includes guidelines for catch and release. At Grimersta we encourage an informed but voluntary approach to catch and release with 70% of salmon and grilse being released over the last five years.

If you require further advice or would like to discuss these measures in more detail please contact Simon Scott.