Tempo River

Also within

Fermanagh County

Habitats

Fast flowing river and stream

Geology & landscape

Geological Period: Carboniferous · Rock Type: Carboniferous Limestone, Limestone, Sandstone

Birds & fish recorded

Fish

Description

Tempo River Freshwater pearl mussel The area is of special scientific interest because of the physical features of the river and its associated riverine flora and fauna, with adjacent woodlands providing additional interest. The river has been modified over much of its length particularly in the upper reaches, however the lower section designated area is notable for the physical diversity and naturalness of the channel and bank with only small areas of artificial channel modification. It is an important river for rare species, particularly the freshwater pearl mussel Margaritifera margaritifera with one of the largest remnant populations of this species known to exist in Northern Ireland. The Tempo River rises near Dooneen Forest, flows through Tempo town finally joining with the Colebrooke River before it enters Upper Lough Erne. The river runs through predominantly agricultural and semi-natural woodland. The underlying geology of the river is old red sandstone, carboniferous limestone and basal clastic bedrock with extensive sand and gravel deposits throughout its length. The river is lowland riffle and run dominated with occasional deeper sections of glide. The stretch of the river designated is typical of low to medium-flowing rivers that are oligo-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, curled pondweed Potamogeton crispus, and Canadian pondweed Elodea canadensis in the channel with reed canary grass Phalaris arundinacea and branched bur-reed Sparganium erectum along the margins. Bryophytes mosses and liverworts are the more common species found i.e., greater water moss Fontinalis antipyretica. The Tempo 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 Tempo 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 and white clawed crayfish Austropotamobius pallipes. The kingfisher Alcedo atthis is also known to occur. 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. The 3-spined stickleback Gastrosteus aculeatus as well as river lamprey Lampetra fluviatilis, brook lamprey Lampetra planeri and the European eel Anguilla anguilla are also found in the river. The river channel of this stretch of river has a tree fringe along a large proportion of its length. Occasionally this fringe widens out up the valley sides to form discreet woodland blocks. Marginal woodland is very important to the river and its wildlife helping to stabilise the river bank and regulate the local climate, while submerged roots create a refuge for fish and crayfish. In addition, many of the insects and other invertebrates associated with the woodland provide food for these species. The main woodland blocks are predominantly upland ash wood which is damp in nature. It is generally basic in type. It has a mixed canopy comprised of, downy birch Betula pubescens, hazel Corylus avellana, ash Fraxinus excelsior, alder Alnus glutinosa, willows Salix spp. and occasionally mature sessile oak Quercus petraea. Beech Fagus sylvatica has been planted in some of the sections particularly in Oldtown Wood where sycamore Acer pseudoplatanus is also found. The shrub understory component includes hawthorn Crataegus monogyna and holly Ilex aquifolium. The ground cover is very variable. Where the wood is less disturbed, species include wood anemone Anemone nemorosa, meadow sweet Filipendula ulmaria, lesser celandine Ranunculus ficaria along with ferns and thickets of bramble Rubus fruticosus agg. https://www.daera-ni.gov.uk/publications/tempo-river-assi

Species mentioned

Insects to look out for

These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.

Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.

Plant communities