Diet, Prey Selection and Biomass Consumption of the Great Cormorant (Phalacrocorax carbo) in Algeria

Abstract

This is the first study on the diet of the Great Cormorant wintering in Algeria. It is carried out in Beni Haroun, the largest dam lake in the country, in north-east of Algeria. The trophic menu of Phalacrocorax carboin this lake is based on four species of fish; Abramis bramas, Carassius carassius, Barbus barbus and Cyprinus carpio. However, Barbus barbus and Carassius carassius represent the two most important species in Great Cormorant’s diet. The total consumed biomass is 155,364.18 g, and the average biomass contained in each pellet varies between 330.7 and 2,953 g. The biomass of consumed fish varies between 36.89 g and 2,501 g. The size of the caught fish records values ​​between 13.7 cm and 52.49 cm. The number of consumed fish per pellet varies between 1 and 9. The results show that the great cormorant of Beni-Haroun Dam Lake consumes between 573 g and 2,353.3 g of fish per day and between 49.8 t and 185 t each month. However, the highest value is recorded in January (between 81.5 and 300.5 t). The Great Cormorant of Beni-Haroun dam lake could have a significant impact on continental and recreational fishing at this site.