Changes in landward and seaward extent of mangroves in the coastal areas of the Hormozgan province

Reduced rainfall and drought occurrence by restricting the migration of mangroves to the uplands have increased the vulnerability of these ecosystems to sea level rise. Therefore, monitoring the changes in the landward and seaward extent of mangroves can provide valuable information on the response and degree of vulnerability of these ecosystems to sea level rise. The aim of this study was to investigate the changes in the landward and seaward extent of mangroves along the coasts of the Hormozgan province. To this end, the mangroves in the Khamir, Tiab and, Jask habitats were mapped using satellite imagery in 1986, 1998 and 2016 and changes in the landward and seaward extent of mangroves were investigated during the periods before and after 1998 (the period of occurrence of long-term droughts on the southern coasts of Iran). The results showed that in the post-1998 period, which corresponds to long periods of drought on the southern coast of Iran, the landward extent of the mangroves was reduced (272.7 ha reduction in Khamir) or the trend of development of landward extent has decreased dramatically, such that in Tiab and Jask the increase in the landward extent has decreased from 463 and 165 ha to 35 and 13 ha, respectively. In addition to the significant effect of reduced rainfall, human factors such as livestock grazing and fueling (especially for the mangroves located in Khamir), development of aquaculture and pollutants have also played an important role in the regression of these habitats.