January 11, 2010

Connecticut scientist leads the way in freezing coral, to give it life later. ~via Caroline Treadway

Coral reefs have been around for hundreds of millions of years, but threats to their immediate future preoccupy marine biologist Mary Hagedorn, who spent her childhood summers exploring the Old Saybrook shoreline and is now pioneering the science of applying human fertility techniques to coral.

WASHINGTON—“Corals have been around for hundreds of millions of years, and we will potentially lose them in the next 25,” said Connecticut native Mary Hagedorn, one of the world’s leading marine biologists. “What’s even more frightening is that we could potentially lose every organism in our ocean.”

Hagedorn, a senior scientist at the Smithsonian Institution for the past 16 years, has pioneered the science of cryopreserving, or freezing at very low temperature, applying human fertility techniques to coral. She’s spent years honing the freezing process for coral sperm, eggs, embryos and now polyps—the tiny beginnings of reefs—to save endangered coral.

Mary Hagedorn and her assistant Ginnie work with coral in Hawaii. Photo courtesy of Mary Hagedorn.

Coral reefs help protect coastlines from storms and erosion, provide food for millions of people, support tourism and offer new cures for diseases, like the AIDS drug AZT, derived from a Caribbean sponge.

Hagedorn’s lab in Hawaii is the only one in the world dedicated to coral cryopreservation. With funding from the Smithsonian, the National Oceanic and Atmospheric Administration, the Morris Animal Foundation and in collaboration with the University of Hawaii’s Institute of Marine Biology andSECORE (Sexual Coral Reproduction), an international organization of professional aquarists and scientists that is concerned about coral conservation, Hagedorn is racing to create frozen archives of live coral tissue before the endangered Elkhorn and Staghorn corals disappear.

The numbers of these two Caribbean reef-building corals have declined more than 90 percent since the mid-1980s. In 2008, the International Union for Conservation of Nature added them to its red list of endangered species.

Elkhorn coral (Acropora palmata) in Belize. This coral forms the major structure ofCaribbean reefs. Photo courtesy of Rafael Ritson-WIlliams, Smithsonian Marine Station.

“The only hope of maintaining coral is either in live culture or frozen in a repository,” Hagedorn said. “A lot of people, even scientists, don’t quite understand or believe the threat. But when you’re down in the Caribbean and you see these ecosystems collapsing in front of your eyes, it’s just so obvious.”

Frozen straws and cryovials containing coral tissue. Photo courtesy of Mary Hagedorn, Smithsonian Marine Station.

To cryopreserve coral, Hagedorn first exposes the tissue to a cryoprotectant, or antifreeze, that pushes water out of the cells by osmosis and prevents formation of damaging ice crystals. She can then safely freeze the cells in liquid nitrogen at minus 198 degrees Celsius. Such cold temperatures suspend all cellular life and enable her to store fragile genetic material indefinitely. Hagedorn later thaws the frozen coral tissue, fertilizes eggs and grows baby coral colonies, which can be shipped to zoos or used to restore reefs in the wild.

“It’s an insurance policy for the corals,” said Mike Henley, invertebrates keeper at the Smithsonian’s National Zoo in Washington. “If the corals all die off in the wild, we have the beginnings of a captive population in zoos and aquaria. If all those die off, Mary’s is preserved in perpetuity. It’s another backup plan. And at the rate they’re dying off, it’s not too soon.”

Nov. 10, 2009-Mike Henley, invertebrates keeper at the Smithsonian's National Zoo, feeds shrimp to coral in the aquarium at the invertebrates exhibit in Washington, D.C. Photo by Caroline Treadway.

Hagedorn attributes her love of the ocean to spending summers on Long Island Sound in Old Saybrook as a child. “I don’t remember not ever loving the ocean,” she said.

Every summer her family drove from New Britain to Point Road on Cornfield Point, Old Saybrook. Hagedorn recalled spending every day in and around the Sound, swimming, playing, collecting crabs and mussel shells. “That was my inspiration for becoming a marine biologist,” she said.

Every day, Hagedorn would watch their neighbor, an old Scandinavian fisherman, cross their yard and head to the rocky point to catch stripers and bluefish after work. “He knew so much about fish and fishing,” Hagedorn said. She would watch him tie flies every night, and remembered once he even caught a shark. “He was very respectful,” she said. “He never caught more than he could eat, and if he did he gave it away.”

Today, Hagedorn has a new summer ritual. Every August, she goes Puerto Rico for the annual Elkhorn coral spawning. Four days past the full moon, at about 9:15 pm, Hagedorn, Henley and a team of international scientists dive into what Hagedorn described as an “underwater blizzard” to collect coral gametes for breeding and freezing.

Elkhorn coral (Acropora palmata) spawns in Belize. Photo courtesy of Rafael Ritson-Williams, Smithsonian Marine Station.

“I feel very fortunate to have lived next to the ocean most of my life,” Hagedorn said. “It’s important to give back, and this is how I give back to the ocean.”

Hagedorn received a bachelor’s in biology and a master’s in biology from Tufts University. She then attended the Scripps Institution of Oceanography in San Diego and graduated with a doctorate in 1983. She did a postdoctoral fellowship at Cornell University from 1984 to 1986. For the last five years, Hagedorn has been in Hawaii, coming back to the Smithsonian every few months.

Henley described Hagedorn as a brilliant scientist who also has people skills. “She’s that mix of being extraordinarily intelligent but you can still connect with her, carry on a normal conversation and not feel intimidated,” he said.

Hagedorn started working on coral, she said, “because nobody had done any cryopreservation of coral at all and I saw it as a huge hole in our conservation need.”

Juvenile Elkhorn coral (Acropora palmata) in Belize. Each coral begins as a polyp about two millimeters in size and can grow to be enormous over hundreds of years. Photo courtesy of Mary Hagedorn, Smithsonian Marine Station.

In 1978, scientists witnessed a mass coral bleaching, she said. Large portions of reefs turned white and died. Coral bleach when their symbiotic partners, tiny photosynthetic algae called zooxanthellae, die in response to environmental or thermal stress. Bleaching events continue, with the largest recorded in 2005.

Scientists cite many causes for declining coral reefs. Bottom trawling and dynamite fishing physically destroy reefs. Rivers carry pollution and sediment from deforestation, development and erosion to the ocean, choking reefs. And fertilizers in particular promote the growth of green algae that outcompete coral.

Hagedorn, Henley and other SECORE scientists like Dirk Petersen from the Netherlands’ Rotterdam Zoo agree that rising water temperatures and ocean acidification play a major role in reef decline.

The ocean becomes increasingly acidic as it absorbs carbon dioxide from the atmosphere. Calcium carbonate, the main component of coral and shells, dissolves in acidic environments.

“You know how your mother always told you not to drink soda because it ruins your teeth?” Hagedorn said. “It’s the carbonic acid in sodas that really does it, and that’s what’s happening in the oceans.”

Nov. 10, 2009-Mary Hagedorn answers questions about the coral breeding techniques she's developed to help save coral reefs during a coral-freezing at Smithsonian's National Zoo invertebrates exhibit in Washington, D.C. On the table In front of Hagedorn sits a tank of liquid nitrogen used to freeze coral tissue, along with fragments of endangered corals.

Hagedorn joins scientists in a worldwide conservation effort to build frozen archives of genetic material to protect endangered species. At the National Zoo, for example, nearly every department freezes something, from milk and sperm to soil and coral.

“Right now my lab is about the only one in the world that’s working on the frozen aspect of coral conservation,” she said. “So I feel almost desperate because there is so much work to be done. We are working on pennies and nickels and dimes to do this.”

She added, “As we go into the future, hopefully this frozen material will never be needed. But if it is, it can stay frozen for hundreds of years.”

Staghorn coral spawning in Belize. Photo courtesy of Rafael Ritson-Williams, Smithsonian Marine Station.

To enjoy more of Caroline Treadway’s stories and photographs, please visit her blog!

You can also check out Mary Hagedorn’s web site here: www.helpmarysavecoral.org

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