Owenreagh River

Also within

Tyrone County Sperrin Scenic Area

Climate exposure

This is about exposure to a nationwide pressure this habitat type carries — not a verdict on this site's own management.

Habitats

Fast flowing river and stream

Geology & landscape

Landscape processes: Peatland / Mire

Birds & fish recorded

Birds

Fish

Description

Owenreagh River Freshwater pearl mussel The area is of special scientific interest because of the associated riverine flora and fauna. The river has been modified over much of its length, particularly in the lower and middle reach sections, however it remains an important river for freshwater pearl mussel Margaritifera margaritifera, with one of the largest remnant populations of this species known to exist in Northern Ireland. The Owenreagh River rises at Black Lough in the Townland of Cragganconroe, from where it flows north-west to join the Owenkillew River. The river runs through predominantly agricultural land with some adjacent peatland in its upper reaches. The river has a pool, riffle and run dominated flow type with occasional deeper sections of glide. The stretch of the river designated is typical of medium to fast-flowing rivers that are mesotrophic generally rather poor in plant nutrients. Vascular higher plants are restricted to a few species such as stream water crowfoot Ranunculus penicillatus var. penicillatus, while bryophytes mosses and liverworts are much more common, particularly greater water moss Fontinalis antipyretica and rushy feather moss Brachythecium plumosum. The Owenreagh River is of particular importance for its associated fauna. It is one of the few rivers in Northern Ireland which still retains a substantial population of the freshwater pearl mussel Margaritifera margaritifera. This species was once very common, covering large areas of riverbed in many of the river systems of Northern Ireland. In recent decades it has undergone a dramatic decline and has totally disappeared from all but a small number of rivers. The decline has been largely due to historical pearl fishing and more recently river engineering works and poor water quality. Only a very few of these populations are viable. Remnant populations such as that occurring at the Owenreagh River are of considerable conservation importance as they are generally genetically and morphologically distinct and may be useful in any future conservation or reintroduction programme. Other animals present include the otter Lutra lutra, evidence of which is found along the whole length of the river, dipper Cinclus cinclus and grey heron Ardea cinerea. Although the fish community has not been extensively surveyed, both Atlantic salmon Salmo salar and Brown trout Salmo trutta are known to be present in the river and areas suitable for spawning are known to occur along the length of the river. https://www.daera-ni.gov.uk/protected-areas/owenreagh-river-assi

Species mentioned

Plant communities