Action to Assess Potential Threats to Freshwater Mussels, Salmon and Water Voles
Acknowledgement: a significant amount of this information has been taken from the Dee Catchment Management Plan Summary Cooksley SL (2007). (2007). Dee Catchment Management Plan Summary
.Legislative Framework – Special Area of Conservation
In 2005, the River Dee and its tributaries were designated as a Special Area of Conservation (SAC) under the EC Habitats Directive, forming part of a network of specially protected sites which represent some of the finest nature conservation areas in the European Community (the Natura 2000 network). The waters of the Dee catchment qualify as an SAC due to their internationally important populations of Atlantic salmon Salmo salar, freshwater pearl mussel Margaritifera margaritifera and European otter Lutra lutra. This means that its water resources must now be managed in order to protect its qualifying species and the habitats that support them.
As well as the three SAC qualifying species (Atlantic salmon, freshwater pearl mussel and European otter) the catchment’s waters support a wide range of specially protected habitats and species. These can be found in Table 3 of the “Dee Catchment Management Plan” and include;
Plants; Pillwort and Wych Elm
Amphibians; Common Frog and Palmate Newt
Insects; Aspen Hoverfly and Northern Blue Damselfly
Fish; Brook Lamphrey and Sea Lamphrey
Mammals; Daubenton’s Bat, Water Shrew and Water Vole
Birds; Osprey, Goldeneye, Snipe, Spotted Crake and Water Rail
Atlantic Salmon
The Dee supports one of the healthiest populations of Atlantic salmon in western Europe and the spring fishery is world famous. However, while numbers of later running salmon and grilse appear to be increasing spring running salmon are going through a period of decreased abundance. Several factors threaten the health of the catchment’s salmon population, including downgraded water quality, man-made barriers to fish passage, introduction of diseases, parasites and alien species and the degradation of juvenile and spawning habitat through civil engineering and pollution.
Freshwater Pearl Mussels
The Dee’s freshwater pearl mussel population of an estimated 1.3 million mussels is one of the largest in the world. However, it has been adversely affected by a combination of reduced water quality, past pearl fishing, catchment drainage schemes and river engineering activity for flood defences and fishery improvements. Although there are a few healthy mussel beds most are failing to achieve European targets set for juvenile recruitment and population density. There is an urgent need to investigate the reasons for population declines, to raise awareness of the presence of, and legal protection afforded to the mussels.
Otter
The Eurasian otter is present throughout the catchment, from the river’s mouth to the upper reaches of its tributaries, including many high-altitude lochs. In order to safeguard the catchment’s otter populations the priorities are to ensure that bankside engineering and management works do not damage or destroy holts or vegetation cover used as couches and to protect and enhance ponds and wetlands used as feeding habitat; there is a need to identify key sites for otters so that these safeguards can be effected.
Water Voles
Water voles are the largest of the British voles. Most water vole populations are associated with water bodies including rivers, ponds, land drains and marshland. They show a preference for permanent slow-flowing water bodies with densely vegetated banks where they feed upon the aerial stems and leaves of waterside plants. Water voles are usually found within 2m of the water’s edge where they dig burrows into soft banks.
The British water vole population has suffered a steady decline throughout the 20th Century owing to habitat destruction and agricultural intensification. This decline has been rapidly accelerated in recent years through predation by feral American mink (Mustela vison). The 1990 population of Scottish water voles was estimated at 2,374,000 whilst the 1998 population was estimated at only 354,000 water voles (Jefferies, 2003).
The 1996 National Water Vole Survey (Jefferies, 2003) recorded remnant water vole populations at a few isolated locations on the Upper Dee catchment. These populations were recorded at Muir of Dess, the upper Derry and the Water of Feugh.
Potential Threats from the Glen Dye windfarm
Potential risks emanating from the Glen-Dye windfarm which could threaten aquatic wildlife species include;
Water pollution can have significant effects on wildlife. These effects include:
There have been media reports of windfarm sites causing contamination of ground water. An example of the Whitelee windfarm is given below. Further research would be required to establish the veracity and latest status of these reports.
“Residents living near Europe’s largest wind farm, the 215 turbine Whitelee farm in Ayrshire, complain that they have suffer from diarrhoea and severe vomiting which they claim was caused by water contamination. It is reported that there was evidence of high readings of E.coli and other coliform bacteria. In addition, readings of the chemical trihalomethane (THM), linked to various cancers, still births and miscarriages, were way beyond safe limits. THMs are formed when chlorine, which is added to the water supply, react with organic particles in the water – due to the disturbance of vast areas of peatlands which dumps huge quantities of carbon into water sources. Scottish Power, who run the wind farm, denied causing the pollution.”
Acknowledgement: a significant amount of this information has been taken from the Dee Catchment Management Plan Summary Cooksley SL (2007). (2007). Dee Catchment Management Plan Summary
.Legislative Framework – Special Area of Conservation
In 2005, the River Dee and its tributaries were designated as a Special Area of Conservation (SAC) under the EC Habitats Directive, forming part of a network of specially protected sites which represent some of the finest nature conservation areas in the European Community (the Natura 2000 network). The waters of the Dee catchment qualify as an SAC due to their internationally important populations of Atlantic salmon Salmo salar, freshwater pearl mussel Margaritifera margaritifera and European otter Lutra lutra. This means that its water resources must now be managed in order to protect its qualifying species and the habitats that support them.
As well as the three SAC qualifying species (Atlantic salmon, freshwater pearl mussel and European otter) the catchment’s waters support a wide range of specially protected habitats and species. These can be found in Table 3 of the “Dee Catchment Management Plan” and include;
Plants; Pillwort and Wych Elm
Amphibians; Common Frog and Palmate Newt
Insects; Aspen Hoverfly and Northern Blue Damselfly
Fish; Brook Lamphrey and Sea Lamphrey
Mammals; Daubenton’s Bat, Water Shrew and Water Vole
Birds; Osprey, Goldeneye, Snipe, Spotted Crake and Water Rail
Atlantic Salmon
The Dee supports one of the healthiest populations of Atlantic salmon in western Europe and the spring fishery is world famous. However, while numbers of later running salmon and grilse appear to be increasing spring running salmon are going through a period of decreased abundance. Several factors threaten the health of the catchment’s salmon population, including downgraded water quality, man-made barriers to fish passage, introduction of diseases, parasites and alien species and the degradation of juvenile and spawning habitat through civil engineering and pollution.
Freshwater Pearl Mussels
The Dee’s freshwater pearl mussel population of an estimated 1.3 million mussels is one of the largest in the world. However, it has been adversely affected by a combination of reduced water quality, past pearl fishing, catchment drainage schemes and river engineering activity for flood defences and fishery improvements. Although there are a few healthy mussel beds most are failing to achieve European targets set for juvenile recruitment and population density. There is an urgent need to investigate the reasons for population declines, to raise awareness of the presence of, and legal protection afforded to the mussels.
Otter
The Eurasian otter is present throughout the catchment, from the river’s mouth to the upper reaches of its tributaries, including many high-altitude lochs. In order to safeguard the catchment’s otter populations the priorities are to ensure that bankside engineering and management works do not damage or destroy holts or vegetation cover used as couches and to protect and enhance ponds and wetlands used as feeding habitat; there is a need to identify key sites for otters so that these safeguards can be effected.
Water Voles
Water voles are the largest of the British voles. Most water vole populations are associated with water bodies including rivers, ponds, land drains and marshland. They show a preference for permanent slow-flowing water bodies with densely vegetated banks where they feed upon the aerial stems and leaves of waterside plants. Water voles are usually found within 2m of the water’s edge where they dig burrows into soft banks.
The British water vole population has suffered a steady decline throughout the 20th Century owing to habitat destruction and agricultural intensification. This decline has been rapidly accelerated in recent years through predation by feral American mink (Mustela vison). The 1990 population of Scottish water voles was estimated at 2,374,000 whilst the 1998 population was estimated at only 354,000 water voles (Jefferies, 2003).
The 1996 National Water Vole Survey (Jefferies, 2003) recorded remnant water vole populations at a few isolated locations on the Upper Dee catchment. These populations were recorded at Muir of Dess, the upper Derry and the Water of Feugh.
Potential Threats from the Glen Dye windfarm
Potential risks emanating from the Glen-Dye windfarm which could threaten aquatic wildlife species include;
- Water pollution or deterioration in the water quality due to;
- surface water run-off from the site & access roads entering the watercourse - such drainage water can contain pollutants such as oil or spilled fuel.
- discharges from the windfarm site entering the water course – these may arise as a result of construction works or maintenance operations or be caused by inadvertent operation or spills.
- Release of organic matter into the watercourse as a result of disturbance or increased erosion of the ground and peat mass particularly during construction of the access roads and wind turbine foundation sites.
Water pollution can have significant effects on wildlife. These effects include:
- smothering of freshwater pearl mussel beds and fish spawning gravel with organic matter, e.g. smothering the salmon redds (the females nest of eggs) which are laid on the gravel beds in autumn.
- nutrient enrichment and eutrophication (e.g. algal blooms),
- oxygen depletion,
- smothering of freshwater pearl mussel beds and fish spawning gravel, e.g. smothering the salmon redds (the females nest of eggs) which are laid on the gravel beds in autumn.
- Reported incidents of Water Contamination from Windfarm Sites
There have been media reports of windfarm sites causing contamination of ground water. An example of the Whitelee windfarm is given below. Further research would be required to establish the veracity and latest status of these reports.
“Residents living near Europe’s largest wind farm, the 215 turbine Whitelee farm in Ayrshire, complain that they have suffer from diarrhoea and severe vomiting which they claim was caused by water contamination. It is reported that there was evidence of high readings of E.coli and other coliform bacteria. In addition, readings of the chemical trihalomethane (THM), linked to various cancers, still births and miscarriages, were way beyond safe limits. THMs are formed when chlorine, which is added to the water supply, react with organic particles in the water – due to the disturbance of vast areas of peatlands which dumps huge quantities of carbon into water sources. Scottish Power, who run the wind farm, denied causing the pollution.”
- SEPA
- Regulation of all discharges to water and land.
- Regulation of larger industrial premises in an integrated manner to protect air, land and water quality.
- Sampling water quality and monitoring the wider environment through chemical and ecological monitoring.
- Lead authority responsible for the implementation of the Water Framework Directive (WFD) in Scotland