A look at life in the protected countryside of the national parks of the Lake District and Yorkshire Dales
Runtime: 60 minutes
The Yorkshire Dales and The Lakes - Malham Tarn - Netflix
Malham Tarn is a glacial lake near the village of Malham in the Yorkshire Dales, England. The lake is one of only eight upland alkaline lakes in Europe. At an altitude of 377 metres (1,237 ft) above sea level it is the highest marl lake in the United Kingdom. Its geology, flora and fauna have led to it being listed under a number of conservation designations. The site is currently owned by the National Trust, who lease part of the site to the Field Studies Council who offer residential and non-residential field courses there. The site was the inspiration for Charles Kingsley's 1863 novel, The Water-Babies, A Fairy Tale for a Land Baby.
The Yorkshire Dales and The Lakes - Natural history - Netflix
Situated in a limestone area, Malham Tarn itself mainly lies on a bed of silurian slate which is covered with marl deposits. The lake's basin was dammed by a moraine at the end of the last glacial period, approximately 10,000 years ago. It used to be about twice its current size, having shrunk due to silting at the western shore; this has formed a boggy region called Tarn Moss. Following deforestation during the Iron Age, the land surrounding the lake has been used for grazing which has prevented further tree growth. An embankment and sluice gate were added to the lake in 1791 by Lord Ribblesdale; this has had the effect of raising the level of the lake by approximately 4 feet (1.2 m). The average annual rainfall over the catchment area is 1,542.5 millimetres (61 in). The lake is home to six species of fish, as well as white-clawed crayfish, great crested grebes, moorhens, coots, tufted ducks and teal. A number of waders such as redshanks, curlews, lapwings and oystercatchers breed in the surrounding area. Two rare benthic copepods, Bryocamptus rhaeticus and Motatia mrazeki, are found in the lake, along with 22 species of molluscs—nine of which are found at their highest altitude in Britain. The lake also contains a number of submerged aquatic plants, while the surrounding area is home to a diverse number of plants including wild cranberry, bearberry, crowberry, dark-leaved willow and purple moor grass. Last seen fifty years ago, captive-bred water voles (Arvicola amphibius) were reintroduced in August 2016. This is the highest reintroduction of water vole in the UK. The lake is located in the Malham and Arncliffe Site of Special Scientific Interest which was established in 1955. In 1992, the lake and its wetlands were designated as a National Nature Reserve. The lake was listed as a Ramsar Convention site in 1993. It is also in the Craven Limestone Complex Special Area of Conservation.
The Yorkshire Dales and The Lakes - References - Netflix