Scilly's Nature Designations SSSI's Higher Moors & Porth Hellick Pool Size: 15.94 hectares % of total area of SSSI's: 3.92 Designated features: Vascular plants General Description Higher Moors, Porth Hellick Pool and the shingle sand bar of Porth Hellick Bank provides a wide variety of habitats, with several rare and notable species. At the southern end of the site the shingle sandbar holds small populations of Sea Kale and Sea Sandwort, whilst the small strip of maritime grassland between the beach and the pool holds abundant Red Fescue, Thrift and Sea Campion, which merges with the wildflowers associated with the wetland around the pool to the north. Porth Hellick Pool is the largest freshwater body on St Mary’s and is fringed by Common Reed, which makes good breeding habitat for species such as Gadwall, Coot, Water Rail and Sedge Warbler and is nationally famous for its rare vagrant birds. The pool however is influenced by the tide and this is reflected in the small population of salt-tolerant species such as Sea Club-rush, Saltmarsh Rush and Brackish Water-crowfoot. The water-logged soils to the north and west hold a wide variety of wetland species including Gypsywort, Water Mint, Hemlock Water-dropwort, Ragged Robin and Royal Fern. Outstanding specimens of Greater Tussock Sedge and Slender-stalked Sedge can be found scattered throughout the site, along with small stands of Yellow Iris and Soft Rush providing a diverse height structure to the site. Practical Management Abandonment of management and a pastoral and agricultural history surrounding the site has led to nutrient enrichment and a gradual drying of the site which has encouraged species such as Common Reed, Hemlock Water-dropwort and Grey Willow to become dominant. The Trust has re-instated rotational reed cutting on the site of varying lengths that are best suited for breeding birds, but at the same time opening up the ground to more light levels that will encourage more desirable plants to flower. The removal of the cuttings ensures that the litter does not accumulate, which helps to keep the site wet. Likewise, the selective removal of Grey Willow during the winter helps to reduce water loss during the summer months. Our Ruby Red Devon cattle graze during the spring and late summer to help further reduce nutrient levels through grazing. By keeping the vegetation short and the small amount of poaching of the ground promotes ideal conditions for more desirable species to re-establish. The large willow carr to the west and the carr the bounds the western edge of the pool are being coppiced on a short rotation to create a varied age-structure across the site, providing feeding and breeding grounds for a wider variety of invertebrates and birds. The opening up of the understorey has seen increases in species such as Royal Fern and Purple loosestrife within 12 months of management. Another major component to the management of Higher Moors is access. Over the past 3 years replacement of the old wooden boardwalk with recycled plastic has begun; this material will last four times as long as wood and re-uses the equivalent of a thousand plastic bottles per metre of boardwalk laid; a great message for recycling and the need to reduce marine plastics.