Between 1997 and 2011, more than a dozen bottlenose dolphins from the Indian River Lagoon on Florida's Atlantic coast choked to death on fish, a new study published in the journal PLoS One reports.
Scientists found 14 dolphins — 12 adults and two juveniles — died after eating fish with "strong dorsal spines," the fin that runs along the top of the fish. The spines puncture the dolphin's esophagus, causing the fish to become stuck.
The dolphin, unable to swallow, dies from asphyxiation due to choking.
Sheepshead and tilapia were the most common fish species found jammed in the throats of dead dolphins.
These "risky prey items" are generally avoided by dolphins, but the study authors suspect that changing environmental conditions in the lagoon have changed the amount of available fish, and as a result, the dolphins' preference of prey.
In some cases, a hook or fishing line was found still attached to the fish, and is believed to have prevented the dolphin from swallowing its prey. This is attributed to an increase in the use of recreational fishing gear in the lagoon.