سال انتشار: ۱۳۸۴
محل انتشار: ششمین همایش علوم و فنون دریایی
تعداد صفحات: ۱
Ahmad Barati – (M.Sc.), Department of Environmental Science, Higher Education Complex of Malayer
Behnam Balmaki – (M.Sc.), Department of Environment Science, Azad University of Arak
sh-eating water birds have important role in food-web of aquatic ecosystems so information on their diet and their effects on fish stock of these ecosystems is important in ecological studies. As a case study, diet and population trends of Great Cormorant was considered. Great Cormorant is dependent on aquatic ecosystem and as other Plecaniformes its diet mainly consists of different fish species. Considering is severe effects on fish stock, this survey was carried out to determining population trends in northern Iran and diet composition of this species. In present research we used counting data during 1999-2003 and case study at Ramsar colony. Result showed increasing trend in Gillian and decreasing in Golestan province. Surveys also showed the main species in Comorants diet consist of Mugilidae, Clupidae, Atherinidae, Gobidae while about 90% of all weight belongs to Mugilidae and Gobidae.