The mouth of Carlingford Lough is an archipelago of reefs and small rocky islands, among them Green Island which is comprised of rock and shingle and lies just across the lough from Greenore. The island has a 13-metre high lighthouse. Strong tides mean the channel is suitable only for experienced sailors, seabirds and seals.
Seal populations in these islands have been under threat in recent years and Carlingford Lough is regarded as a frontline in the battle to sustain both harbour (common) and grey seal populations. The lough has a number of ‘haul out’ sites (where the mammals leave water temporarily to rest or reproduce). Green Island is the most significant of these.
Historically, Green Island has been a significant location for birdlife, too, hosting substantial flocks of common, arctic, sandwich and roseate tern, but the island has been severely affected by natural erosion which has reduced it to a mere shingle spit. Tern populations have dwindled, accordingly. There is concern, too, for future seal populations and Loughs Agency is involved in conservation and monitoring projects.
There is strictly no access to Green Island but good views can be had of its basking seals from Greencastle Pier on the northern shore of Carlingford Lough.