A common mangrove tree, the grey mangrove (Avicennia marina) is the only species found in the Al Thakhira Nature Reserve on the eastern coast of Qatar, 40 miles (64 km) north of Doha. This tree of the Verbenaceae family is found on the coasts of the Persian Gulf and the Indo-Pacific. It is one of the first species to have settled in the intertidal zone of the coast, where it contributes to the formation of mangroves. Its long roots fix the silt and allow new sediments to settle behind them, which contributes to sedimentation and fixing the coastline. Highly resistant to high salinity conditions, grey mangroves are perfectly adapted to the shallow waters of the Persian Gulf.