By Susan Milius
A right whale may weigh some 70 tons, but unlike other marine mammals studied so far, it tends to float rather than sink at great depths.
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Electronic monitoring of 95 right whale dives shows that the animals swim the whole downward leg of 70-meters plus plunges, says Douglas P. Nowacek of Woods Hole Oceanographic Institution in Woods Hole, Mass. On the way back up, however, the whales stop swimming and just float to the surface, Douglas and his colleagues report in the Sept. 7 Proceedings of the Royal Society of London B.