Cruninish Island ASSI

This area is of special scientific interest because of its species-rich wet grassland and breeding waders. Species-rich grassland tends to occur only where land management is not intensive, in particular where traditional farming practices have been maintained. As a result, it is not a widespread habitat in Northern Ireland and is often fragmented, consisting of individual fields, parts of fields or banks. Species-rich wet grasslands, like those found at Cruninish Island, are a particularly scarce resource in Northern Ireland.

Cruninish Island is a lightly grazed drumlin island in the Northern section of Lower Lough Erne. The island has a central ridge that gently slopes down to the lough shore. The top of the island is drier and freely draining and as water moves down the slopes towards the lough wide extensive areas of flushed vegetation have been created. This combination of topography and the related soil hydrology has resulted in an interesting range of species-rich wet grasslands over the island. These vary from drier, grassy rush pasture on the more elevated areas to fen meadow, with base-loving plants present along the slopes and shoreline.

It is one of the most important sites for breeding waders in Northern Ireland. The density of nests, at nearly 3 per hectare, is one of the highest recorded in Northern Ireland.

The vegetation on the island is dominated by sharp-flowered rush, with a variety of grasses and sedges and in places is markedly species-rich. This provides cover for nests and young birds.
Other important factors for breeding birds are the heavy nature of the soils which remain wet even in summer and the adjoining lough shoreline, which provide an abundance of food for adults and young birds. The island is also relatively free from disturbance and predation.

Wet grassland in the form of purple moor-grass and rush pasture occurs over most of the island, which remains wet due to high levels of precipitation from the westerly geographical position. The wet conditions and local water logging result in the occurrence of species such as sharp-flowered rush, meadow thistle and purple moor-grass. The purple moor-grass and rush pasture occurring on the flushed slopes of Cruninish Island is described as fen meadow and occurs when there is free movement of water through the soil. Typical herb species associated with fen meadow vegetation include marsh thistle, meadowsweet, meadow thistle, Devil’s-bit scabious, tormentil, bog pimpernel and lesser spearwort. Sedges are abundant in this habitat and include tawny sedge, carnation sedge and glaucous sedge.

In the drier central area of the island sharp-flowered rush and Yorkshire-fog are frequent within the sward. The wet grassland in this area is less species-rich and is characterised by species such as soft-rush, creeping buttercup and white clover.

The variation in hydrology and related topography, and past and present management has resulted in a considerable range of species present in a relatively small area.
In addition to the species already mentioned water figwort, a species of note was recorded around the shoreline.

Cruninish Island is an area of semi-natural grassland and associated habitats that have been managed in a traditional way. As such, it provides valuable feeding and roosting sites for a range of animals, including mammals such as Irish hare and invertebrates such as green-veined white and meadow brown butterflies.

Site Related Documents

Site map (.PDF 552Kb), Citation document (.PDF 135Kb) and Views about Management document (.PDF 78Kb).