Winter Conditions for Fish (image) Umea University Caption It is difficult to be a fish when the bottom of the river is covered with ice. Winter image from the river Orkla in Norway. Credit Knut Alfredsen Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.