Saturday, January 26, 2008

Studying dolphins in their natural habitat

You can imagine his reaction. Up from Port Charlotte, he was visiting his grandma, Charmeine Smith of Treasure Island. She’d arranged for him to spend time with one of her friends.At 17 years old, JR Smith must have quietly sighed as he agreed, “Sure, Grandma, love to spend the morning with your friend.”The trials of youth.His grandmother’s friend studies dolphins. She took him to see.He was impressed by the vigor of the 32 dolphins they saw arguing over sex, hurling into the sky and shooting through the water like cannonballs.

His grandmother’s friend was impressed too: Comfortable, courteous and curious, JR inspired her to think about dolphins and sharks in a whole new way.It started when he asked me if he could name the next dolphin Osiris.Absolutely. Osiris was a chief Egyptian god, the source of life, fruitfulness and all beneficent agencies.

After he had been slain by his brother Set, the personification of evil, Osiris became the judge of the dead and roamed the earth as the sacred bull Apis. Neatly, the next dolphin who needed a name was a mother with an older calf. Osiris and her calf Apis are not residents of the backwaters. They probably live in the Gulf of Mexico and visit here during the summers. They split their time evenly between solitude and socializing with a small, predictable group of companions, mainly other mothers with younger calves.

Osiris has a good memory because she remembers us although we don’t see her that often. Apis still swims with Osiris though old enough to strike out on its own. It’s very energetic, even for a dolphin its age, and plays particularly hard with other calves. But it plays nice. Creative and bold, Apis plays long games of catch or keep away and ventures over to ‘snort the engine,’ poking and prodding pals en route. But companions have yet to replace Osiris in Apis’ life.We first noticed Osiris’ shark scars one warm September morning last year.

Two groups of dolphins swam slowly around the edge of a large bay, far from boat traffic. They swam rhythmically, pacing the valiant efforts of 3-day-old Babyface.New mother Face and good old Tanks flanked the baby tightly. A second rank of dolphins paced nearby, Osiris and X among them. Calves Little X and Apis played briskly as they went. Osiris had two shark scars. The scar in front of her dorsal fin was old and well healed.

The scar behind it was newer, thicker and still healing. We didn’t see Osiris and Apis again until they returned this May. Sometimes miles beyond John’s Pass, they were usually within a mile of it either on the inside in the backwaters or outside in the Gulf of Mexico. They seemed to come inside for some specific activity; when they finished, they headed for the Gulf directly. Inside, they hunted the fruitful shallows, snoozed in large groups, or wandered the periphery of bottlenose bullfights. One shiny autumn day, dolphins slid into John’s Pass from the backwaters and slipped into the Gulf. The Gulf was as flat as a facet on an emerald.

A pushy ebb current shoved backwaters against bulky Gulf waters, making broad glassy circles of poetic disturbance.But the calm belied violence: Osiris had a raw shark bite in front of her dorsal fin where the old scar had been. It’s hard to approach dolphins with new shark bites. We don’t try too hard; they’re already stressed. Luckily, perhaps, Osiris’ companions knew about sharks; Front Slash, Scarface, Leading Dent and Sharkey all have scars of their own.Among the 27 percent of local dolphins with shark scars, Osiris is in the small subset of dolphins with multiple scars.

She revealed that dolphins could get bit at least three different times. This was the new way of thinking JR inspired.His namesake suggested something else. Osiris was thin this summer. A fruitful investigation would be the association between feeding stress and shark bites. Chronic hunger creates vulnerability, which predators are designed to find. Carefully collected data could reveal the direction of the relationship: get thin and get bit or get bit and get thin. Dear Osiris, may the gods of beneficence be with you.

Quick "Facts about Dolphins"