Cromarty Firth Fishery Board

The Conservation Volunteers and Fishery Board staff are on track to finish clearing Rhododendron from the banks of the River Orrin this winter.  In some areas chainsaws are being used by wherever possible a technique called ‘lever and mulch’ is being used.  This method uses hand tools to cut branches back and then leverage is applied to the main stems to either break them at ground level or uproot them completely.  The cut branches then act as a mulch to prevent regrowth.  This method can be very effective and requires less follow up treatment than traditional cutting and burning.

Before clearance works

After clearance works.  Not only are stems removed but also roots and stumps. The lack of vegetation under the rhododendron shows how damaging it is to riverbank habitats, increasing erosion and supressing native plants.

Later in the spring with the support of the Woodland Trust native trees will be planted into some of the areas previously cleared on the Orrin.

Salmon spawning is underway around the Cromarty Firth region.  Although the dark peat stained water makes counting redds difficult, salmon can be seen spawning in many shallows in upper and middle catchments.  At the lower end of many of our rivers spawning may not start for another month and may continue into January.

Salmon spawning in the River Orrin on the 14th of November

Bailiffs have been busy clearing debris jams to allow spawning access for salmon and trout.  Although fallen timber in rivers is generally good for fish habitat, in some cases large accumulations of debris, particularly after felling operations can block access for migrating fish.  Jams were cleared on the Upper Conon, Peffery and Alness.  On the Peffery as part of the restoration of habitat timber has been added to the river to create a variation in flow and depth.

As part of the Cromarty Firth Invasives project funded through RAFTS and the SEPA restoration fund, Japanese knotweed treatment continued into October.  This is the best time to treat knotweed, as the plants are preparing for winter dormancy they take the herbicide they are treated with down into their root system more effectively.    Stands were treated either by spraying or by injecting herbicide directly into their stems.

Knotweed stem injection

The findings of research into the genetics of salmon populations in the Cromarty Firth region, which were carried out as part of the FASMOP programme, can be seen in the Cromarty Genetics Report in the Publications section.   The research shows genetically distinct populations in different parts of the region and also a genetic distinction between hatchery origin and wild stocks in the Conon system. This shows that by restricting stocking to areas where mitigation for hydro impacts are required, distinct wild spawned populations have been maintained downstream of these areas.  The report also shows the importance of both hatchery and wild spawned salmon to the rod catch.

Works are ongoing to restore the River Peffery and its sea trout stocks. This project is on a catchment wide scale and involves many partners including; SEPA, Forestry Commission, Highland Council, Moray Firth Sea Trout Project, Cromartie Estate, The Conservation Volunteers and Dingwall Environment Group.   Project works range from modifying upland drainage to the removal of invasive non native species in the lower reaches.  The project also involves the removal of man made obstacles to migration and replanting of native trees along the banks.

In the middle reaches with advice from The Wild Trout Trust and support from the SEPA restoration fund, river channels degraded by agricultural drainage are being restored.  Whilst the river is still constrained by flood banks on either side, local timber and field stone is being used to create meanders in the channel and a more varied sequence of pool and riffle habitats.  This increase in the variety of flow and depth of will help restore sea trout habitat.

Compacted areas of gravel are being cleaned with a powerful leafblower and the new structures installed are designed to maintain areas of clean gravel for spawning.