On Labor Day, our team was notified by Amber Kuehn, head of sea turtle patrol on HHI and LMMN volunteer, that there was a dead bottlenose dolphin in Hilton Head. This animal was found floating near Coligny Beach Bridge and was recovered by LMMN volunteer Rich Urbanski. Rich was able to tow the dolphin to shore and pass off to Amber. We were quickly notified by Amber that this dolphin showed evidence of boat strike injuries. Our team met Amber half way to retrieve the animal and bring it back to the NOAA NOS laboratory in Charleston for an in-depth necropsy.
Four propeller strikes on the back
This was a female, sub-adult bottlenose dolphin. Some scavenging was present along the throat and she was missing her dorsal fin and fluke. Before the necropsy was underway, detailed measurements and photographs were taken externally. Anytime human interaction is suspected for a stranding case, a careful examination and necropsy becomes even more important. This dolphin had four lacerations evenly spaced along the top of her body. Only one laceration penetrated into the blubber and muscle. Further examination of this wound showed no tissue reaction and no evidence of sub-dermal hemorrhaging. Therefore, this boat strike is likely to have occurred after this animal had already died.
Not only was this young female emaciated, there was also evidence of congested lungs with parasites. Histology samples were sent off and once results are back, we will update this post with a more definitive cause of death.
Even though the boat strike was not the cause of death for this animal, it is still a good reminder that responsible boating is necessary to avoid collisions with marine life. Obey no wake zones, remain observant, and reduce speed when dolphins are sighted. When a dolphin or manatee dies, they will float, so being observant to avoid striking a carcass is just as important to protect the safety of you, your passengers, and your boat!
Thank you to everyone who helped on this case: Rich Urbanski, Amber Kuehn, Brooke Brown, Bonnie Ertel, Kerryanne Litzenberg, Valerie Sprinkel, Lola Renauer, Claire Goubeaux, and Josh Ratay!