As marine mammal species often play a large part in their ecosystems, it is possible that the sea mink was an important intertidal predator. It may have been similar in diet to the American mink, and may have consumed seabirds, seabird eggs, and hard-bodied marine invertebrates, though in greater proportions.[1] Fur traders reported that sea mink dens had two entrances, and were made in the rocks piled up by the waves.