Yearling sockeye salmon (smolts),Oncorhynchus nerka, trapped at the outlet of Babine Lake, Canada, on their way from the lake downstream to the ocean were tested in round orientation tanks. With a view of the sky, the smolts oriented towards the lake's outlet in the normal magnetic field (Fig. 3) and in a field rotated 90 ° counterclockwise (Fig. 4).

Under opaque covers, the smolts displayed a bimodal distribution. In the normal magnetic field, they oriented towards or away from the lake's outlet (Fig. 5). In the altered field, the axis of the distribution was rotated 56 ° away from the axis in the normal field (Fig. 6).