Originally Posted by corvette

Certain types of large shark species prey on bottlenose dolphins. Dolphin remains are often found in the stomachs of tiger sharks, dusky sharks, and bull sharks (Shane, et al., 1986). Killer whales occasionally prey on bottlenose dolphins as well, but documented cases are rare (Klinowska, 1991). Humans, however, also prey on dolphins. Many dolphins are killed inadvertently when they become tangled in commercial fishing industry nets. In the recent past, furthermore, bottlenose dolphins have been taken directly for meat, leather, oil, animal feed, and fertilizer (Klinowska, 1991).

http://www.personal.psu.edu/users/e/x/exv131/