April - Lochs and Lakes

Our habitat highlight for April is Freshwater Lochs!

Scotland has over 30,000 freshwater lochs, which range massively in size, however only about 350 of these are of notable size, the rest being lochans (small lochs).

Did you know, ‘Loch’ is the Scottish Gaelic word for a body of water which is completely or almost completely surrounded by land?

Loch Ness is the largest of all Scottish lochs by volume, and contains more water than all English and Welsh lakes combined! Many of the large lochs are found in U-shaped valleys, formed by glaciation. The types of flora and fauna within a loch depends on its physical dimensions, water chemistry, sediment, and the catchment area’s geology. Lakes and lochs are important stop-off points for many migrating birds.

One of the main threats to Scottish lochs is pollution, which can lead to eutrophication – increased nutrients leading to excessive algal growth (algal blooms), blocking sunlight from entering the water and depleting oxygen, and therefore causing a loss of fish and other fauna. Non-native species also threaten loch ecology, such as New Zealand pygmyweed and Canadian pondweed. With climate change and increasing temperatures, many lakes and lochs could show gradual drying up, which may threaten numerous species.

Look out for our species of the month next!