"A study showed that sea otters will restrain baby seals and then begin copulation; sometimes drowning it during the 105-minute-long process. Even after the seal is dead, the otter will hang on to the carcass and continue to mate with it for up to a week."
"When food is in short supply things can get ugly. Some males will hold otter pups hostage until the mother pays a ransom of food to the male."
Part of the mating process involves holding the female’s head under water, which kills over 10% of female otters.