Ocean Watch
By Susan Scott
Fertile turtle astounds
local researchersSome call her Maui Girl, but a more appropriate name might be Fertile Myrtle. She's a 22-year-old green sea turtle that in 2000 crawled onto a Lahaina area beach, dug a hole and laid eggs. She did this not once, but three, maybe four times that summer.
This was big news then because "5690," Maui Girl's official number, was the first green turtle to nest on Maui in half a century.
This turtle had an official number because in 1980 she'd been enrolled in a tagging study. At that time, researchers attached metal tags to young turtles' flippers. These tags, however, often fell off over the years, and workers lost valuable information about turtles' lives.
To try a more permanent type of tagging that worked with lizards, National Marine Fisheries Service biologists George Balazs and Bill Gilmartin brought 175 hatchling turtles from French Frigate Shoals (where most greens nest) to Honolulu. There, researcher John Hendrickson swapped a small plug of light shell from a turtles' underside with a dark plug from its back.
To compare the progress of grafted turtles to nongrafted turtles, some hatchlings received only a metal tag.
For a year, under contract, Sea Life Park workers fed, monitored and cared for the study babies. In 1981, when the turtles had reached the size of dinner plates and weighed about 7 pounds, biologists released them at various sites throughout the state. No. 5690 began life on her own in Hilo Bay.
So far, this turtle is the only one of that batch, grafted or not, ever seen again. It's possible, however, that others are around but have lost their metal tags.
Besides having her 20-year-old tag still intact, Maui Girl has marveled researchers with the production this year of an exceptionally large number of offspring.
After taking a year off from egg laying, which is typical for green turtles, Maui Girl returned to Lahaina in May of 2002. There she dug her first nest of the year and laid a clutch of eggs. By mid-July this industrious female had laid a total of four egg clutches.
During her fourth, and researchers believed her last, nesting night, workers attached a one-pound tracking device to the turtle's back. This instrument signaled a satellite once a day, enabling Balazs to track her course.
The turtle stuck around the Maui area and on July 24 laid her fifth clutch of eggs.
"What a marvelous turtle," Balazs wrote in an e-mail. "But in ways, they all are, with so many mysteries of their lives yet to be unlocked."
And this turtle held even more mysteries. She proceeded to lay a sixth and seventh clutch of eggs on that Lahaina Beach. Seven is the most ever laid by Hawaiian green turtles in one season; one to three is more common.
All of Maui Girl's nests have hatched now, but Lahaina lights confused some little turtles, and they headed for town instead of the ocean. State and federal biologists, plus helpful citizens in the area, redirected the hatchlings when they went astray, and most made it to the ocean.
Balazs and state aquatic biologist Skippy Hau estimate that 5690 produced about 400 living, swimming offspring this year.
Balazs writes that this supermom is currently living in Napili Bay, "enjoying the grand Hawaiian life she has chosen for herself in Maui's coastal waters."
Marine science writer Susan Scott can be reached at http://www.susanscott.net.
