An estimationofconsumption amount of fish by Great Cormorant (PhalacrocoraxCarbo)onfish Culture Pools in Shooshtar area (Khouzestan)

The present study done to estimatimating the consumption of cultured fishes by Great Cormorants in Shooshtar fish culture pools in the north part of khouzestan during the September to March, 2010-2011. 77 Great Cormorants were captured, the stomach of 42 samples of cormorants were full and contained fish. The study revealed that the Great Cormorants consumed about 11 kg/ha of the existing cultured fishes in pools during winter. The greatest amount of consumption was observed 4.92 kg/ha in February. The difference in the average weight of the food consumed by the Great Cormorant in various months of winter was not significant (p-value>0.05). Moreover, the overall study of stomach content of Great Cormorant showed that consumed food included %99.75 of fish and 0.25 unknown materials. The cultured fishes consumed by the Great Cormorants weight range was between2-560 gr and the length range was between4 and 35 cm. The calculation of the weight percentage of fishes consumed by the Great Cormorant recorded in the following The Common Carp 70.78 (%), the Silver Carp 9.8 (%), the Grass Carp 8.91 (%), Big-Head Carp 5.85 (%) and Liza subviridis 4.41 (%),there is a significant difference between the weight percentages of the Common Carp and other consumed species (p-value