Rhizophora mucronata an extinct mangrove species re-introduced to Ras Ghanada Island, Abu Dhabi, United Arab Emirates after 100 years

Summary

Rhizophora mucronata, a mangrove species absent from the UAE for about a century though historically native, was reintroduced to Ras Ghanada Island, Abu Dhabi, through a joint research program begun in 2001 by the Department of the President's Affairs and the Environment Agency-Abu Dhabi, using propagules imported from Pakistan given similar climatic conditions. After nursery research establishing optimal soil media, salinity, shade and pot size for seedling growth, 350 seedlings at least 50 cm tall were planted in 2003 at a Sand Hill site with a mix of bare ground and areas with existing native Avicennia marina, spaced 3 x 3 metres and planted only during low tide. No monitoring or further plantation work took place between 2004 and 2008, but the first evaluation in July 2008 found 80% survival (280 of 350 seedlings) forming an established plantation; a second evaluation in 2011 found survival had dropped to 50% (140 plants), though remaining plants were healthy, dark green and had developed typical prop roots, with plants growing best where sheltered by adjacent A. marina, which appeared to protect them from gazelle grazing, hot dusty winds and barnacles. Difficulties included the logistics of importing propagules from Pakistan, harsh summer heat and winds, grazing damage from gazelles, and barnacle fouling. The project rates itself successful, crediting rigorous nursery and site-selection research, proper seasonal timing (November-December), careful handling during transplantation, and the protective benefit of planting alongside young natural Avicennia marina stands.