The river's name derives from *uɨsk, a
Common Brittonic root meaning "abounding in fish", and a
cognate of both the
Irish iasc, meaning "fish", and
pysg, the plural word for "fish" in
Welsh. The same root separately developed into the
English Axe and
Esk, the
Welsh Usk, though not, as some have claimed, the word
whisky, this latter being from the
Classical Irish/Gaelic "water" (the fuller phrase being ; ; ; "" ("water of life")). The river's name occurs in
Exeter ("fortress on the Exe") and many other settlements along its course, including
Exford,
Up Exe,
Nether Exe,
Exwick,
Exton,
Exminster, and
Exebridge, where it is joined by the
River Barle. The seaside town of
Exmouth is at the east side of the estuary mouth, and
Dawlish Warren is at the west, with its long sand spit extending across the mouth. The river fuelled Exeter's growth and relative importance in medieval times. The city's first industrial area was developed at
Exe Island, which was created in the 10th century by digging a series of
leats into the sandy and marshy land bordering the river. The island became home to numerous
watermills producing paper and textiles. Tides on the river are limited at Trews Weir in Exeter, two kilometres upstream of
Countess Wear, the site of a former
weir commissioned by the
Countess of Devon in the 13th century. The
Exeter Canal bypassed this weir to enable ships to reach Exeter
Quay. At high tide, the estuary forms a large body of water that is heavily used for water sports, especially sailing, windsurfing and water skiing. Railways run along both sides of the estuary. The
Avocet Line from Exeter to Exmouth on the eastern side, and the
South Devon main line on the western. The latter is on a causeway, the
South Devon Railway sea wall from
Powderham to Dawlish Warren. The
Exmouth to Starcross Ferry carries passengers across the mouth of the estuary during the summer months, linking the harbour at Exmouth with a pier adjacent to
Starcross railway station on the South Devon main line. At low tide, extensive
mud flats are exposed, and these are an important feeding source for wading birds. Along with other
rias in
South West England, the Exe estuary is an important site for wintering waders. Dawlish Warren is a favoured site for birdwatching. The river has a low pH but does not suffer from a serious
acid rain problem. It is populated with wild
brown trout, and in the lower reaches coarse fish including dace, chub, perch, roach, pike and bream and some
grayling, the average size being . There is a run of
Atlantic salmon and a sparse run of sea trout. Just below the union of the River Barle is Black Pool, which is one of the best, and highest salmon pools on the river. The smaller fish species present include stone loach and there are good reasons to assume others are present. ==2008 clearing operation==