Sharp IslandLocation of Sharp Island within Hong KongKiu Tau connected by tombolo. The rocks in the foreground are part of Sharp Island Special AreaBeach at Half Moon BayKiu Tsui BeachTombolo leading to Kiu Tau.
When the predicted tides at Ko Lau Wan is lower than or equal to +1.40 meters,[4] visitors are able to visit Kiu Tau (橋頭), an inshore islet, on foot.
Different kind of volcanic rocks can be found on Sharp Island. The most frequent ones are rocks with a peculiar pattern on the surface. Other rocks have an unusual pineapple-shaped form.
History
Origin of the different kinds or rocks
It is believed that about 140 million years ago a volcano was located in Sai Kung. Sharp Island was on the margin of the caldera. This is probably the reason for the widely distributed different volcanic rocks from different geological periods around Sharp Island.
Formation of the tombolo
The sea currents near Sharp Island pushed sand and gravel near the shore. After several years they formed a tombolo, a natural bridge made of different sized rocks and sand – connecting Sharp Island and Kiu Tau (橋頭). At high tide the tombolo is submerged in water and thus can only be seen when the tide goes out.
Biodiversity
There are over 70% of stony corals coverage around the island. An endangered flora Tetrathyrium subcordatum is found on the south of the island.
Conservation
A small portion of Sharp Island is designated as the Sharp Island Special Area (橋咀洲特別地區). It covers 649 square metres and was designated in 2011.[5] The area is located west of the pier at Kui Tsui Beach.[6] The geology of the area is characterised by volcanic rocks of the Cretaceous period.[7]
Transportation
Sharp Island is accessible by ferry from Sai Kung Town.
