There are five small islands in the Mercury group which are all nature reserves. The bare coastal cliffs are up to 150m high and have become home to the noxious weed Boxthorn. Boxthorn itself is a highly problematic species. Its hard woody stem support stiff limbs which carry perpendicular thorns up to 100mm long.
The plant can trap birds and the cuttings adhere to the surrounding bush. Abseil Access Ltd was called upon to determine the extent of the problem. Abseil drops are established over infested areas and the number and location of the plants were mapped for future eradication and monitoring.