Greencastle is located within an area of immense environmental significance, which is recognised nationally and internationally. The Mourne area is designated an Area of Outstanding Natural Beauty (AONB) as well as an Environmentally Sensitive Area (RSA), while the Carlingford Lough shoreline including Greencastle is an Area of Special Scientific Interest (ASST).
This area of Carlingford Lough is also a Special Protection Area (SPA) under EC Birds Directive 74/409 and is further listed as a Wetland of International Importance under the Ramsar Convention.
These designations give the hamlet of Greencastle and its shores, home to myriad flora, fauna, birds and other wildlife, an unusual importance in environmental terms, not just as far as Northern Ireland is concerned, but the British Isles and Europe.
Consequently they also make the area something of a dream for naturalists and birdwatchers, professional and amateur alike. Several species of seals use the inshore islands for pupping and breeding and bats live and breed in the many farm out-houses in the area.
The abundant wildlife and rich ecology of the area is apparent all around Greencastle itself, on land, in the air and in the sea.
Greencastle shoreline falls into the Carlingford Lough Special Protection Area lying between Killowen Point and Soldiers Point. It qualifies under an EC directive on the Conservation of Wild Birds because it supports internationally important breeding populations of Sandwich Tern (Sterna sandricensis). Colonies of this species can be found on Green Island, the largest island of the Lough which lies just off Greencastle Point and is managed by the RSPB.
It further qualifies under the same directive for supporting nationally important breeding populations of the Common Tern (Sterna hirundo), also found on Green Island.
Roseate Terns (Sterna dougalli) have returned to the area after an absence of six years with two breeding pairs recorded in 1997. The site also supports internationally and nationally important numbers of other birds.
Additionally the site forms part of an extended cross-border site which supports internationally important numbers of overwintering Light-bellied Brent Geese. These can be spotted on Mill Bay, Greencastle at low tide. Several species of seals use the inshore islands for pupping and breeding and bats occupy many of the farm out-houses in the area.
Furthermore the shore is part of an area listed as a world Ramsar site under the Convention on Wetlands of International Importance, especially Waterfowl Habitat. The site qualifies by supporting an important collection of vulnerable and endangered Irish bird species. As indicated, it also supports internationally important breeding populations of Sandwich Tern and nationally important numbers of Arctic Tern as well as other species.
The objectives of the Convention are to stem the progressive encroachment on, and loss of, wetlands both now and in the future and to encourage a policy of wise use of wetlands. A wetland is defined as being an area of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, and including areas of intertidal marine water. The UK ratified the Convention in 1976.
The waters at Mill Bay and Greencastle Point have immense ecological significance, harbouring a number of important and unusual species. ‘These include anemones, starfish and the Green Sea-Urchin. Mill Bay also contains three out of the four major sedimentary communities which exist in Northern Ireland.
Its mud flats and muddy sands contain diverse plant and animal life, attracting interest from botanists and geologists as well as naturalists and bird-watchers.
Among the area’s other diverse wildlife, otters have recently been spotted on the rocks around Greencastle Point. The shore itself is a haven for aquatic species such as mussels, oysters, edible and velvet crab, shrimp, sandeels, razorshells and winkles.