Sea Scout den at the Clontarf end, and a small cafe. At the end of the North Bull Wall is the Star of the Sea (Realt na Mara) statue, funded by Dublin Port workers and sailors, and dedicated by the then archbishop of Dublin in 1972. Continuing development The island continues to grow and it is a possibility that within the next half-century continued deposition may lead to its merging with the mainland at Red Rock in Sutton, forming a lagoon, changing the make-up of the area's wildlife and landlocking two dinghy sailing clubs. However, the risk of this is considered small due to the strength of currents and depth of water in Sutton Channel. Geology and hydrology The island is primarily a sand structure approximately 5 km long and under 1 km wide. The southeast-facing side is a flat beach, Dollymount Strand, backed by marram-grass-anchored dunes, scrub and marsh. On the northern side of the Bull, between the island and the mainland, is a large linear saltmarsh complex backed by mudflats all of which are covered at high tide. Several of the city's small rivers and streams enter the bay here, notably the Naniken River, the Santry River, Fox Stream, Blackbanks Stream and Daunagh Water. Furthermore, the city's second-largest river by volume, the River Tolka, has its estuary facing the city end of the island, into which the Wad River, and a combination of several smaller watercourses, also flow. Fauna Birds A wide range of birds visit Bull Island, with a more limited set nesting there; most are either winter feeders, or pass through in spring and autumn. Wading species include Eurasian curlews, Eurasian oystercatchers and redshanks, while others include shelduck, teal, pale-bellied brent geese, and various gulls. Also encountered are grey plovers, bar-tailed godwits, northern shovellers, little egrets, reed buntings , Common cuckoos and little terns. Mammals There were a number of terrestrial mammal species on the island for decades, with one becoming extinct in the 2010s and one added. Species include the pygmy shrew, brown rat, red fox, field mouse, hedgehog, European rabbit and Irish hare, the latter having become extinct between 2016 and 2019, while the stoat has been observed since the mid-2010s. There have been claimed sightings of bats also but it is not clear if there are any roosting sites on the island. Hares, which are believed to have populated the island from the