Goosander predation and its potential impact on Atlantic salmon smolts in the River Tana estuary, northern Norway

In the summers of 1981 and 2000, 288 goosanders Mergus merganser were sampled in the estuary of the River Tana in northern Norway, which has the largest wild Atlantic salmon Salmo salar stock in the world. Based on 2308 otoliths found in their stomach contents, sandeels Ammodytes sp. were found to be the dominant prey, and only one pair of Atlantic salmon otoliths was found. This suggested that goosanders were not significant predators on Atlantic salmon smolts in the estuary, probably because of the high abundance of sandeels and other marine prey fishes, at least in these particular years. (c) 2005 The Fisheries Society of the British Isles.