Lochs
Scotland has more than 30,000 fresh water lochs, ranging from small lochans to the likes of Loch Lomond or Loch Leven. The conditions in each loch differ varying from acidic waters with low nutrients to more alkaline waters with higher nutrient levels. Of all Scotland’s lochs, Loch Lomond has the biggest surface area of 71km² and Loch Ness has the highest volume with 7,452 million cubic meters. Most of Scotland’s lochs can be attributed to glacial activity in the past. Most large lochs are formed as a result of U-shaped valleys carved out by glaciers where rivers run into and leave a body of water. Smaller lochs can be created by the formation of glaciers on mountain side creating corries for loch water to sit in. A special group of lochs that are common in the UK are dystrophic water bodies. These are coloured yellow or brown with substances from peaty soils. These water bodies are usually situated in areas of raised bogs or blanket bogs. These lochs have been recorded up to an altitude of 928m.
In the Forth
Within the Forth District Loch Katrine, Loch Venachar and Loch Leven are the biggest lochs. Loch Leven is a RSPB nature reserve and a good example of a productive loch habitat. The loch is also an important feature for surrounding wetland as it helps to support a lowland raised mire and wet grassland, which is a resource for up to 20,000 wintering pink-footed geese. Loch Leven is home to many species. A regular feature at the loch are lapwing and each year Loch Leven is home to 6% of Scotland’s wintering whooping swan population. The loch is home to many fish species such as brown trout, northern pike, European eel and common minnow. The loch is renowned both nationally and internationally as a brown trout fishery and for being one of Europe’s most important wetland sites.Â
Loch Katrine is the deepest loch within the Forth, with depths of 500ft +. It is also the largest loch within the District and is the source of Glasgow’s water supply. Loch Venachar was raised, which expanded its area, due to Loch Katrine being used to supply water for Glasgow. Loch Venachar was raised and acts purely as a compensation loch for the River Teith due to the water being removed from Loch Katrine.Â
Threats to Habitat
Pollution with nutrients is the most common threat to the flora and fauna in Scotland’s lochs as it may cause changes in present species and increased growth of algae. As a result of an algal increase, light might not hit the submerged plants severely affecting survival of such species and subsequently having a negative effect on the ecosystem of the loch. Non-native invasive species also threaten the ecology of our lochs. Invasive plants include New Zealand pygmyweed, water fern, Canadian pondweed and Nuttalls pondweed.