The Tweed Foundation in the Valleys

Map showing the preliminary results of the project

Radio Tracking

Between 1994 and 1996, The Tweed Foundation carried out a radio tracking project whereby salmon were caught and fitted with radio tags in the estuary at Berwick and then tracked to their eventual spawning destination. The results showed that the Ettrick and Yarrow catchment took the majority of early running fish, those tagged in the estuary before 31st August, but also took summer and autumn run fish as well.

A smaller scale radio tracking project was carried out in the Ettrick catchment in 1998. Fish were caught and tagged at a trap operated at the Howden ( Morris) cauld at Selkirk. The purpose of the project was to determine whether the different types of fish spawn in the same areas or whether they use different areas. This information is very important because it allows us to direct our habitat enhancement schemes to the areas of the catchment being used by spawning fish and it also helps us to highlight and prioritise remedial action to obstacles that are barriers to fish movement.

Howden Fish Counter

Fish jumping at the Howden cauld

As the radio tracking highlighted the importance of the Ettrick catchment for spawning fish, it became obvious that for research purposes it would be necessary to have accurate counts of fish entering the Ettrick.

To that end, in 1996 the Tweed Foundation installed a Vaki Infra Red Beam fish counter in the fish pass of the Howden ( Morris) cauld at Selkirk. The counter counts fish ascending the pass as well as those descending through the pass. When a fish passes through the scanner it breaks the infra red beam and the scanner then creates an image of its size and shape, an underwater camera can also be used with the counter to obtain visual data. This information is then relayed back to a bankside computer and display unit. From that data, accurate counts of Salmon, Sea Trout and Brown Trout entering the Ettrick can be gained which is used to help interpret the results of the juvenile fish surveys of the Ettrick catchment carried out by the Foundation.

Overkirkhope Bridge Apron

Overkirkhope Bridge Apron

One of the major problems fish heading to the spawning grounds have to overcome are obstacles in the rivers and burns. Obstacles can take many forms such as caulds, weirs, dams, fords, water intakes and bridge aprons. Some obstacles, such as the Howden cauld, have fish passes to let fish through, but unfortunately a great many of the obstacles do not have fish passes and so the fish cannot reach the spawning grounds.

The Foundation has spent a great deal of effort and funds altering or removing obstacles to allow free passage for fish. One of these obstacles was the Overkirkhope bridge apron. A juvenile fish survey carried out in 1988 showed good numbers of fish above the bridge, but between 1988 and 1993 a large concrete apron was built to protect the foundations from erosion and juvenile fish surveys carried out in 1993 showed very few young fish above the bridge, indicating that fish were not getting over the apron to spawn.

In 1995 the Tweed Foundation modified the bridge to incorporate a fish pass, shown in the picture, and open up the burn to spawning fish. Foundation staff returned in 1998 and carried more juvenile fish surveys; the results showed that fish numbers had increased to the same levels found before the apron had been installed. A number of other obstacles in the Ettrick and Yarrow catchment have also been successfully removed or modified.

The Rankle Burn

The Rankle Burn (before)

The Rankle Burn (after)

The radio tracking project showed that the Rankle burn was an important spawning tributary for the spring salmon entering the Ettrick. However, the Rankle also had some of the poorest habitat in the catchment.

The 'before' picture shows that livestock grazing has removed much of the bankside vegetation leading to bank erosion, also visible in the picture. When the banks erode, the burn becomes very wide and shallow, which means it heats up rapidly in the summer, which can be potentially fatal to juvenile fish. The lack of deep water or overhanging vegetation means there is little cover for fish from the heat, direct sunlight and predators. The lack of vegetation also means less organic input ( leaves and invertebrates) into the water which form the staple diet of fish.

The 'after' picture shows some of the remedial work undertaken by the Tweed Foundation to improve waterside habitat.

Approximately 6000 metres of fencing have been erected to keep livestock away from the riverbanks to allow the vegetation to regenerate. The picture shows a variety of wild flowers growing in the foreground. To assist this process, approximately 1000 native broadleaf trees have been planted along the waterside.

A technique known as log and Christmas tree bank revetment has been used to protect eroding banks and to help them naturally revegetate. Current deflectors have also been used to restore the natural flow patterns and to create areas of deeper water for larger juvenile fish. Large boulders have been distributed into the water to break up strong flows and to give cover for juvenile fish.

A further major project similair to that in the Rankle has been carried out on the Douglas burn in the Yarrow Valley, another important burn for spawning fish. Much of the upper Ettrick and its side burns such as the Tushielaw. Hopehouse and Deloraine burns as well as many burns in the Yarrow Valley have also been fenced to improve the habitats.

The improvement in habitat quality does not just benefit fish- various rare flower and plant species have been seen growing since the grazing pressure has been removed and much cover and food has been provided for the mammals and birds species associated with burns in the Ettrick and Yarrow catchment.