Bastun is usually taken to be an Anglo-French nickname or surname originally meaning "stick", while thwaite is from Old Norse þveit ("clearing").

This, along with a large percentage of cultivable land within this drainage area, makes Bassenthwaite Lake a fertile habitat.

[citation needed] The lake contains salmon, trout, pike, perch, minnow, dace, ruffe and eel, though the predominant species is roach.

[citation needed] Cormorants have been known to fish the lake and herons can also be seen; at the turn of the 19th century there was a report of 60 nests in a heronry in nearby Wythop Woods.

[4] The Environment Agency attributed unacceptable levels of phosphate in the catchment to Keswick wastewater treatment works, Greta Grove pumping station and the associated overflow.

[6] Water company United Utilities was fined £27,000 in 2011 for allowing raw sewage to pollute nearby Pow Beck watercourse.

[6] It has been reported that the wide gravel spreads between Derwent Water and Bassenthwaite Lake provided the best centre within Lakeland for Neolithic farming communities.