The invention relates to a seismic streamer (1) for underwater towing at a towing speed in ice-free or wholly or partially icy water, the streamer (1) is provided with birds (2) spaced along the streamer, the streamer including the birds (2) has negative buoyancy, the birds have wings (8) which can be set so that the birds during movement in the water apply an upward or downward force on the streamer. The streamer (1) is provided with buoyant bodies (4) spaced along the streamer, the buoyant bodies are connected to the streamer by spacer elements (5), the streamer including the birds, the buoyant bodies with associated spacer elements and any other equipment together have positive buoyancy. The invention also relates to a corresponding method for securing a seismic streamer (1) from damage at a substantial reduction or cessation of towing speed when towing underwater in ice-free or wholly or partially icy water.