Due to its rural nature, the river is clean and healthy, supporting a wealth of wildlife.

[9] Between the junction of Fryup Dale and Lealholm the river passes through a narrow, steep-sided and wooded valley known as Crunkly Ghyll.

[10] At its head it formed a massive dam blocking the flow of water from above and creating a lake running back up the valley to Commondale.

In Victorian times, the Ghyll was home to a large rockery garden, open to the public, but long since washed away by flooding of the river.

The small villages along the river were at one time of great importance to the north-east, with coal[11] mined in the valleys, and iron ore dug from quarries on the surrounding moors.

[13] Since 1987 a byelaw has been in place to protect dangerously dwindling populations of salmon and sea trout.

[25] The river was not used for shipping save for the area in and around Whitby harbour (which was notable for its whale industry and its shipbuilding).

This area was also host to shipbuilding and timber processing plants, but most of this industry was defunct by the First World War.

[30] This area was also the location of a whale blubber rendering plant, which was said to have afflicted the town with an awful stench.

[33] Every year on Ascension Eve (38 days after Easter Sunday), a ceremony is held at 9:00 am on the east side of the upper harbour, to celebrate the planting of the Penny Hedge.

[35] The hedge needed to be cut by a penny-knife and planted as specified otherwise the men's lands would be forfeited to Whitby Abbey, and as it was a penance as part of the hermits forgiving them their crime, if they did not carry it out, they could have faced execution charges.

[36] from source (flows into the North Sea) The Esk Valley Walk runs along part of the length of the river.