Size: 10.16 hectares

% of total area of SSSI's: 2.50%

Designated features: Phragmites australis swamp

General Description

Situated immediately east of Hugh Town, the low-lying relatively flat expanse of Lower Moors SSSI is a typical example of a topogenous mire, whereby seasonal fluctuations of freshwater from rainfall cause the partial breakdown of plant material, which because of the lack of oxygen turns to peat.  This process began many millennia ago and still continues today.  The site is dominated by Common Reed, with areas of dense and scattered Grey Willow.  The seasonally water-logged soils have abundant Hemlock Water-dropwort, Lesser Spearwort, Marsh Bedstraw and small populations of Royal and Lady Fern.  At both the northern and southern extremities of the site the wet grassland has abundant Soft Rush, Yellow Iris along with small populations of Greater Bird’s-foot Trefoil and Ragged Robin.  The site has several, small shallow open water areas which are known to be very important feeding areas for passage and over-wintering migrants and waders including Snipe and Water Rail.  In recent years the pool has attracted such rarities as Great Blue Heron, Purple Heron and Bluethroat, along with less common rail species such as Corncrake and Spotted Crake.

Practical Management

Approximately 200 years ago a network of ditches were installed to attempt to drain the land, so that livestock grazing could occur.  Because the topography of the site is so flat the drainage was unsuccessful, but the grazing helped to create a diverse and rich wetland.  However, with the abandonment of grazing about 100 years ago the site began to dry out, as scrub re-invaded and leaf-litter was no longer being removed.  During the last 5 years management by the Trust is successfully re-wetting the site.  We are working towards an ambitious target to remove 2ha. of Grey Willow encroachment , along with implementing a 4 year reed cutting programme across 2.5ha. of the site to open up the ground to more light to encourage the re-establishment of wetland plants.  We have also re-commenced grazing in the wet grassland areas to enhance this sward.  The results so far have been very encouraging with for example, a 5000% increase in the number of Ragged Robin recorded.  The site now has abundant Royal Ferns returning and an increase in the number of the rare (in Scilly terms) Southern Marsh Orchid.  The wet grasslands have seen a reduction in the amount of Common Reed, Hemlock Water-dropwort, Sea and Soft-rush and last year saw Purple Loosestrife, Floating Sweet-grass and Marsh Pennywort return to those areas.

A 2 year hydrological study has also been carried out to understand how the wetlands work, as both Lower and Higher Moors play a critical role in the archipelagos water supply and provide essential protection against flooding.  The results of the study have enabled the Trust to begin a water level management regime which will enable the site to remain wetter during the summer months and to improve water levels during the winter.  The implementation of this management is also having a positive impact against saltwater intrusion as high tides combined with winds from the south were having an impact on the ecology of the site.