Editing Ruhr (river) (section)

== Environment ==
The Ruhr was extensively used by adjacent factories for cooling-water and was heavily contaminated by industrial discharge in the 19th and 20th century, with significant negative impact. Large sections of the river were straightened, changing the habitat of the river and it's shore significantly. This led to a decline in various fish species, particularly the brook trout and related salmonids. 

The establishment of dozens of smaller and larger dams largely prevented migratory species like salmon and the [[European eel]] from ascending or descending the river as part of their lifecycle. Salmon have not been observed in the river in decades. Stocks of the European eel have dwindled. Both eel and brook trout stocks rely heavily on release of juveniles as part of conservation efforts.

Since 2013, the district government of [[Arnsberg]], funded partially by grants of the European Union,<ref name=":0">{{Cite web |title=Renaturierung der Ruhr |url=https://www.bra.nrw.de/umwelt-gesundheit-arbeitsschutz/umwelt/wasserwirtschaft-und-gewaesserschutz/fluesse-und-auen/renaturierung-der-ruhr |access-date=2025-04-20 |website=www.bra.nrw.de |language=de}}</ref> is investing heavily into renaturation efforts to restore the natural river & habitat surrounding it. This includes various aspects, most significantly the removal or addition of bypasses to barriers such as dams along the whole river, to re-enable natural fish migration. Additionally, the river bed is widened substantially in sections, reducing the depth of the river and slowing down the flow of water, to enable natural reproduction of native fish, insects, etc. 

Two sections of the renaturation have been completed (in Wickede & Witten)<ref name=":0" /> with two more projects currently underway. 18 additional projects are still in planning stages and as of now, the river is not fully passable for migratory fish.