The ₁₄C activity of a series of recent bones of Arctic marine mammals was measured and corrected with respect to ₁₃C levels; apparent ages were determined as 30-190 years. This was similar to, or slightly higher than apparent ages of marine shells from the same regions. When not corrected for isotopic fractionation, ₁₄C dates of bones of Arctic marine mammals were approximately 300 years too old compared to contemporaneous terrestrial plant material. Bones of human beings who subsisted on a mixed terrestrial and marine diet also showed considerable apparent ages. See AATA 17-865. -- AATA