Ecology and conservation of the socotra cormorant (phalacrocorax nigrogularis) in the Eastern Arabian Gulf

Socotra Cormorants (Phalacrocorax nigrogularis) are regionally endemic, vulnerable seabirds limited to the Arabian Gulf and Sea of Oman regions. Global populations have undergone catastrophic declines, with several major colonies gone completely extinct in the central western Arabian Gulf. Major threats include breeding habitat loss due to oil exploitation, disturbance at breeding colonies, fisheries by catch and occasional hunting. Six of 12 large colonies have become extinct in the United Arab Emirates. Colonies in the western Gulf seemingly have suffered considerably, with much lower numbers compared to historic records. In comparison, the single colony on Siniya Island, Umm Al Quwain, in the eastern Arabian Gulf is arguably the largest in the UAE and possibly the entire Gulf with an increasing population of about 35,000 breeding pairs. Breeding studies indicate variable reproductive success possibly linked with habitat features, weather, diet and impact of predators. Planted trees on the island provide protection from soaring temperatures early in the breeding season and improve breeding performance. The island hosts native Red Foxes (Vulpes vulpes) and feral cats (Felis catus) that have a negative impact on the breeding performance. Additionally, ample evidence exists of conflict with fishermen. Many birds die annually to fishermen's nets or lines and fishermen generally perceive them to be competitors. Diet studies indicate that fish taken by cormorants have almost no overlap with commercially important species. The island is subjected to periodic disturbance by fishermen collecting sea grass from lagoons. Additionally, the island is littered with a wide range of plastic and other debris. Current trends in the population could be offset if any or all of the threats continue to increase. Conservation and management of this population must focus on removing plastics, eliminating disturbance during breeding seasons, engaging local fishermen to reduce by-catch mortality, protecting coastal areas to safeguard foraging sites, and creating awareness.