Answers sought from dolphin deaths

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Kate Schaffer, Wendy Wyman and Pete Holster measure a bottlenose dolphin on South Middle Beach in South Yarmouth, where it was found dead early Tuesday morning. The animal had been rescued the day before in Dennis and was released with a satellite tag at West Dennis Beach about 11 p.m on Monday.Cape Cod Times/Steve Heaslip

SOUTH YARMOUTH — The male bottlenose dolphin rested on his side in the sand at the end of Judan Way. A small army of volunteers and staff members from the International Fund for Animal Welfare made its way down the beach, towing a load of supplies in a cart with oversized sand tires.

The dolphin's eggplant-colored skin was smooth and firm and reflected the sunlight back into their eyes as they knelt to measure it. Some of the workers assembled a tent and set up what would become a busy lab with card tables brimming with scores of tiny tissue sample bottles, vials to hold fluids and labels of all sizes.

Tarps were spread on the sand for the bins of sharp scalpels and long fillet knives and the dozens of plastic-lined cardboard boxes that would hold large square flaps of blubber and steaks of burgundy red muscle.

This is the other side of dolphin and whale strandings, when the rescue that volunteers, passers-by and professionals hope will be successful fails. Except for the occasional beach walker or jogger, few get to see this. Those who do stop to watch don't linger, as the dolphin's skin and blubber are slowly peeled off, muscle removed and internal organs examined for telltale signals that might answer the riddle of this stranding.

As grisly as it might seem, a necropsy, the animal version of an autopsy, is fundamental to scientific research into the health of marine mammals, for answers as to why they come ashore, and to gauge the impact humans may be having on the denizens of the deep.

"He's big," IFAW volunteer Kate Shaffer said Tuesday, kneeling beside the dead animal. "This is the biggest one I've ever seen."

Nearly 9 feet long, over 1,000 pounds, and nearly 7 feet in girth, it took 14 people to lift the big male bottlenose Monday evening from where he had come to rest on the flats off Crowes Pasture in Dennis. Rescuers also saved a smaller female that was swimming with the male. Both animals were deemed healthy enough to be released and were transported to Nantucket Sound and let go. Unfortunately, both died overnight and were found on Yarmouth beaches early Tuesday morning.

The necropsy on the male was performed that afternoon; the female will be examined today. Hundreds of tissue samples will be set to laboratories around the country to be tested for disease and contaminants.

Bottlenose dolphins are usually found far offshore, said IFAW assistant stranding coordinator Jane Hoppe. A yellow identifying tag was still attached to the male's dorsal fin, where it had been bolted on Monday evening along with a sophisticated satellite tag, whose twin antennae broadcast the dolphin's position when he surfaced to breathe. Part of the reason for the necropsy was to see what rescuers may have missed in deciding the male was healthy enough to be fitted with a $2,000 tag, Hoppe said.

A visual evaluation showed that life at sea wasn't easy. Many of the animal's teeth were ground down to nubs, meaning he was likely fairly old, said Hoppe. Circular lesions on the skin teemed with tiny parasites, the dorsal and flukes were all frayed, and a pectoral fin was blunted in what appeared to be an old bite wound. There was a deep, scarred-over notch, possibly caused by friction from a past entanglement, where the fluke attached to his powerful lower abdomen.

Occasionally, an unsettling gurgle, accompanied by the swampy smell of internal gases released by decomposing flesh, issued from his open mouth. A glassy eye stared up at the sky, its large pupil nearly lost in surrounding dark skin of the dolphin's heavy lids.

As a half dozen people struggled to roll the big dolphin over, the weight of 1,000 pounds pressing down on internal organs caused a gassy exhale, like a long angry growl.

The four members of the dissection team each had a backup taking notes on a clipboard as they progressed. Veteran stranding volunteer Betty Lentell removed several large teeth that would reveal his age. Meghan Hartwick, a guest investigator working at the Woods Hole Oceanographic Institution, sliced carefully through the surprisingly thin skin, revealing the creamy white layer of blubber that girded the animal like a heavy coat. Pulling back the skin and blubber, she revealed bright strings of red muscle like corned beef and the white larvae of blubber parasites.

Hartwick was looking for distinctive bubbles of gas, part of a study on how deep-diving marine mammals deal with what we would call the bends. As Lentell removed the massive wine-colored layers of muscle in the abdomen that propelled the dolphin through the water, she explained that the dolphin had relatively small lungs and that much of the oxygen he used on forays to the ocean bottom was stored in the myoglobin contained in this tissue.

Working on just a few hours of sleep after the failed rescue the previous evening, the team members would continue for hours as sunlight faded, and a cold wind blew, always hoping that, with each tissue sample, they were building on the knowledge that might someday provide answers, including why dolphins and other marine mammals strand.

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