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Blelham Tarn is a large valley tarn in the Lake District to the north of the hill Latterbarrow. The settlements of Outgate, Low Wray and High Wray are close by. The tarn is drained to the northeast by the short Blelham Beck into Windermere. This beck was previously straightened and lowered.〔(Blelham Tarn & Bog - Unit 2 )〕 Fish species in the tarn include brown trout, eel, perch, pike and roach,〔(Blelham Tarn )〕 much of the tarn shore is reedbed and waterfowl present can include great crested grebe, whooper swan and golden-eye.〔 The tarn is regularly monitored by the United Kingdom Lake Ecological Observatory Network and is characterised as eutrophic and monomictic〔 and has suffered from agricultural water pollution〔(Blelham Tarn & Bog - Unit 6 )〕 with large quantities of blue-green algae in the summer.〔 The lake temperature at various depths varied over the period July 2012 to November 2014 between 2 and 25 Celsius as the air temperature (3 m above the surface) varied between -3 and 22 Celsius. Over the same period the pH varied from 6.4 to 9.8 and the dissolved oxygen ranged from 7 to 14 mg/l〔(Data from the UK Lake Ecological Observatory Network )〕 Blelham Tarn and Bog, with a total area of 49 hectares, is designated a site of special scientific interest〔(SSSI units for Blelham Tarn & Bog )〕 and Blelham Bog is designated a National Nature Reserve〔(Cumbria's National Nature Reserves )〕 The bog contains various species of sphagnum moss, bog myrtle, cotton-grass and the white-beaked sedge; and rare caddis-flies and vertigo lilljeborgi.〔 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Blelham Tarn」の詳細全文を読む スポンサード リンク
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