When I respond, or seek responses, I think of the Internet Republic and the people [[whump]] and the places who have made our water world Eden brave and free and fair. Permitted, required, and impossible. Stand alone or stand with, whose choice to what degree [[Thn/]] O[[thn/]]ne water world Eden under "We the people" – created by whom?

…coral sperm banks continued.

Frozen Sperm Offer a Lifeline for Coral
Published: July 23, 2012

(Page 2 of 2)

Still, both strategies may ultimately be necessary. “Protecting fish communities, making sure water quality is good, all of those efforts can buy decades of time,” said Nancy Knowlton, a prominent coral-reef biologist at the Smithsonian. “But if we continue on this greenhouse-gas emissions trajectory, the only place we’re going to be able to find many corals will be in Mary’s freezers.”

Scientist at Work Blog: The Naked Coral Hypothesis (July 19, 2012)
Scientist at Work Blog: A Healthier Reef, Holding a Mystery (July 19, 2012)
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Since 1949, when the British biologist Christopher Polge successfully froze and thawed a vial of rooster sperm, scientists have deployed the technique in dozens of species, including humans, pigs, oysters and bumblebees. Yet every species is different in its sperm’s response to freezing, and mastering so-called cryopreservation for a single species can take years of experiments.

Eggs and embryos, because of their much larger size, are even more difficult to preserve. “Sometimes the next step is getting punched repeatedly in the face,” said Kenneth Storey, a cryopreservation researcher at Carleton University in Ottawa. “This is hard work, hard empirical work. It’s uphill.”

In her work in Hawaii and elsewhere, Dr. Hagedorn has encountered not just those frustrations but also the quirky, mysterious nature of corals. Simultaneously animal, vegetable and mineral, corals are colonies of simple creatures called polyps, housed in the distinctive calcium-carbonate sculptures that form coral reefs.

Coral sex is poorly understood: The periodic broadcast spawns of coral sperm and eggs were essentially unknown to scientists until the early 1980s, when a team of Australian researchers on a nighttime dive began to encounter upside-down blizzards of spawn. Researchers are still unsure why so many spawns are tied to phases of the moon.

Like the Fungia on the campus of the Hawaii Institute of Marine Biology, corals sometimes stray from their expected spawning schedules, and Dr. Hagedorn has spent anxious evenings on shore in Puerto Rico and Belize, waiting for endangered corals to begin their yearly spawn in the open water.

But luck was with her last fall, when she and a group of colleagues traveled to Australia at the invitation of the Australian Institute of Marine Science. Using techniques developed by Dr. Hagedorn, they collected and froze sperm and cells from colonies of Acropora tenuis and Acropora millepora, two of the roughly 400 coral species native to the Great Barrier Reef.

The coral cells and sperm are now stored in liquid nitrogen at the Taronga Western Plains Zoo in New South Wales, alongside frozen sperm samples from koalas, yellow-footed rock wallabies and dugongs.

In 2009, JoGayle Howard, a National Zoo researcher known as the “sperm queen,” produced healthy black-footed ferret kits by inseminating a female ferret with sperm collected and frozen more than 20 years earlier, adding valuable genetic diversity to the endangered species. Dr. Howard, who died in 2011, remains an inspiration to Dr. Hagedorn: When her work is interrupted by tropical weather or the vagaries of coral spawns, she likes to remember that even one vial of frozen sperm could be worth all the trouble.

“Think about the black-footed ferret,” she said. “Just a few individuals can get a population started again.”

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