N ATU RALIST'S 



NOTEBOOK 



pilot whale pods are found throughout the 

 world's open oceans. 



"Pilot whales are always off the coast 

 of North Carolina," says Hohn. 



They typically swim along the Gulf 

 Stream and Continental Shelf hunting for 

 squid — often diving 700 to 800 meters for 

 their favorite food. 



"We are at the southern edge for 

 long-finned pilot whales and the northern 

 edge for short-finned," says Craig Harms of 

 North Carolina State University's College of 

 Veterinary Medicine (CVM). 



Harms led a team from NC State's 

 CVM that performed necropsies, or animal 

 autopsies, on 12 of the 33 pilot whales 

 stranded last year. Along with a team of 

 researchers from various universities and 

 laboratories, he collected and studied tissues, 

 blood samples and stomach contents. 



Despite all this information and 

 analysis, the whales' deaths remain a mystery. 



TRIPLE TRAGEDY 



At about 8 a.m. on Jan. 15, Gretchen 

 Lovewell, coordinator for marine mammal 

 stranding response at NOAA's Beaufort 

 Laboratory, receives a page about a live whale 

 on a northern beach in North Carolina. 



The second report in just a few hours 

 creates concern that whales could be spread 

 along the beaches from Oregon Inlet north 

 almost to Virginia, a distance of almost 30 

 miles. 



The latest stranding turns out to be a 

 minke whale calf that likely separated from its 

 mother and starved. Wendy Walton, leading 

 a team from the Virginia Aquarium Stranding 

 Response Program ( VAQS), arrives in Corolla. 

 She euthanizes the whale, with plans to return 

 the next day to take the carcass to Virginia 

 Beach for a necropsy. 



Back in Nags Head, near Oregon Inlet, 

 access to the pilot whales is restricted by 

 narrow beaches and a rising tide. A VAQS team 

 led by Denise Boyd is forced to cease work 

 because of the high tide. 



As the first day progresses, the tide 

 washes away two pilot whales, leaving 3 1 

 animals — seven still alive. But the poor 



ABOVE: A tractor helps move 

 pilot whale carcasses before burial. 



condition of the whales, the weather and the 

 narrow size of the beach pose serious risks for 

 the teams. The water is too shallow and rough to 

 facilitate easy release of the stranded whales. 



As evening approaches, the teams 

 eventually reach and euthanize each pilot whale. 



Stranding response team members arrived 

 from 16 institutions. 



The primary team from the NOAA lab 

 in Beaufort was led by Hohn. In addition to 

 the NOAA team, the participants represented 

 University of North Carolina at Wilmington 

 (UNCW), Duke University Marine Laboratory, 

 the Smithsonian Institution, NC State and the 

 Virginia Aquarium and Marine Science Center, 

 among others. 



Early the second day, the teams begin 

 collecting as many samples as possible from 

 each animal, and moving whale carcasses in 

 danger of washing away. Hohn rotates among 

 small groups, providing additional necropsy 

 supplies, along with food and a warm vehicle 

 for breaks from the cold and windy weather. 



With their task almost complete, the 

 researchers receive a third report about two 

 other live whales on the beach north of Cape 

 Hatteras. These dwarf sperm whales die shortly 

 after a team arrives on the scene. The teams 

 necropsy the whales immediately. 



UNSOLVED MYSTERY 



Early news accounts suggested the 

 standings could be related to Navy sonar 

 testing along the Outer Banks. But NOAA 

 reports that none of the animals had a major 

 injury or illness associated with whales 

 involved in sonar-related standings. 



Previous necropsies of stranded 

 whales revealed that sonar may cause gas 

 bubbles in blood vessels and hemorrhage 

 to vital organs. This is similar to 

 decompression sickness — also known as 

 "the bends" by scuba divers — a condition 

 experienced by humans who ascend too 

 quickly from deep waters. 



Active sonar transmissions occurred 

 over a three-day period prior to the Jan. 15 

 standing. 



But NOAA's technical report says it 

 is not possible to conclude definitively that 

 they played no role in the stranding. 

 Some of the whales did have infectious 

 diseases and parasitism. "Individual causes of 

 death could be the result of an acute condition, 

 including metabolic and electrolyte imbalances, 

 which is likely in all of the live-stranded ceta- 

 ceans," according to the report released earlier 

 this year. 



Some of the whales had subdural 

 hemorrhage — bleeding in the brain — possibly 

 caused by struggling on the beach post- 

 standing. Several other whales had chronic 

 ailments such as cardiac disease, joint problems 

 and inflamed tissues in the abdomen. 



None of the pilot whales were emaciated 

 and all initially stranded alive, according to 

 NOAA's report. 



The cause of the stranding "involving pilot 

 whales, dwarf sperm whales, and a minke whale 

 is not definitively known," the report states. 



Previous North Carolina standings have 

 included the species from the January 2005 

 event. "Since 1992, 31 species of cetaceans 

 are known to have stranded along the coasts of 

 North Carolina," the report says. 



"Most standings in North Carolina are 

 sick whales, or older whales that have lost some 

 of their teeth or dependent calves that have been 

 separated from their mother and have not been 

 feeding," says Harms. 



28 Coastwatch I Autumn 2006 I www.ncseagrant.org 



