Editing River Don, Yorkshire (section)

==Flora and fauna==
[[ficus|Fig]] trees grow on a stretch of the river bank in Sheffield. The seeds do not normally germinate in the English climate, but the use of river water for quenching hot metal in some of the foundries resulted in water temperatures rising above 20 deg C. At these temperatures, germination occurred. Most of the trees are over 50 years old, and the demise of such industry along the river has reduced water temperatures, so that there is no evidence of new trees growing.<ref>{{cite news|url=https://www.theguardian.com/books/2005/dec/10/featuresreviews.guardianreview11 |title=Review of ''Flora Britannica'' |first=Richard |last=Mabey|work= The Guardian|date= 10 December 2005| access-date= 30 July 2010}}</ref>

The industrial nature of the region led to a severe [[pollution]] problem for the river, but efforts to improve the water quality and habitat have met with some success, as [[salmon]] have been reported in the river near Doncaster.<ref>{{cite web |url=http://www.environment-agency.gov.uk/news/117835.aspx |publisher=Environment Agency |title=Combined Sewage Overflow appeals, River Don |access-date=8 August 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100410142936/http://www.environment-agency.gov.uk/news/117835.aspx |archive-date=10 April 2010 }}</ref> In 2013 a fish pass was built at a weir on the Don at Meadowhall. The weir had been a barrier to the passage of fish for 150 years prior to the construction of the fish pass.  It was also planned to construct a fish pass at Sprotbrough weir. Grayling, barble, chub and dace, as well as salmon are expected to benefit from the construction of a series of wiers.<ref>{{cite news |date=20 May 2013 |title=River Don 'fish pass' re-opens spawning grounds |work=BBC News |url=https://www.bbc.com/news/uk-england-south-yorkshire-22602455 |access-date=26 July 2023 |archive-url=https://web.archive.org/web/20130611011221/https://www.bbc.co.uk/news/uk-england-south-yorkshire-22602455 |archive-date=11 June 2013}}</ref> In 2020 a fish pass was built at Masbrough Weir, Forge Island, in Rotherham. It is the last of 18 obstructions along the River Don to be made passable by salmon, enabling them to swim to their spawning grounds in Sheffield. The completion of the Masbrough Weir fish pass and a fish pass at Sanderson's Weir, in Sheffield means the fish have a route from the North Sea to Sheffield. The project to open-up the river to salmon took 20 years to complete.<ref>{{cite news |date=2 June 2020 |title=River Don salmon return for 'first time in 200 years' |work=BBC News |url=https://www.bbc.com/news/uk-england-south-yorkshire-52888116 |access-date=26 July 2023 |archive-url=https://web.archive.org/web/20200720090746/https://www.bbc.com/news/uk-england-south-yorkshire-52888116 |archive-date=20 July 2020}}</ref>