Answers on Kitty Hawk Humpback Whale's Death Could Take Weeks or Months

Little remains on the beach at Bennett Street in Kitty Hawk, North Carolina, after the necropsy of a juvenile humpback whale: a faint odor in some spots and tire tracks in the sand. The animal, which measured 27 feet and weighed at least 19,000 pounds, washed ashore on Friday, Dec. 27.

Mike Remige, director of Jennette's Pier, said the arrival was not entirely unexpected. "Although it was a surprise, it wasn't a complete surprise. We generally see whales this time of the year," he said.

Remige has spent the past eight years working with the Marine Mammal Stranding Network whenever marine life comes ashore in the Outer Banks. He said the pier's involvement grew out of a gap in the partnership in the area. After Jennette's Pier opened in 2011, staff were hired, and they saw both a chance to fill that gap and a desire to take part in important scientific work.

Remige was present on Saturday when crews carried out the necropsy. The cause of death is still unclear, though some hemorrhaging was found. The whale's carcass was already heavily decomposed when the team reached it, which complicates the picture. "We don't know if the hemorrhaging that we saw was caused by something either premortem, which would have been the cause of death, or postmortem," Remige said.

Large whale species typically migrate south along the coast in November and December on their way to the Caribbean, where they usually remain until March. Remige named North Atlantic right whales, humpbacks and mainly sperm whales among them. In the Caribbean, he said, the animals give birth and mate over the winter.

A whale stranding at this time of year is therefore not unusual. Still, federal officials declared an "unusual mortality event" for humpback whales on the Atlantic Coast in 2017, and North Carolina has recorded 30 humpback deaths since 2016.

According to Remige, much of the available data points to vessel collisions as the main driver of that event. "What a lot of the data is showing is the main cause of the unusual mortality event are ship strikes and boat strikes, which is unfortunate; it's the reality of the situation," he said.

Although such strandings never become easier to witness, they give researchers an opportunity to learn more about the animals. "This is our opportunity to really dig in and learn more about their anatomy, learn more about their behavior, learn more about the species in general," Remige said.

Tissue samples collected during the necropsy will now be analyzed, and determining a cause of death from them can take weeks or even months. The results may also help people find ways to coexist with marine life in the future.