As it stands, things don’t look good for the world’s coral. We’ve lost 40% of the world’s reefs already, and every forecast shows the situation getting worse. As well as traditional threats like overfishing and coastal development, corals now have to contend with climate change, which not only warms the water but also makes it more acidic.
That’s why Mary Hagedorn thinks we need to move beyond traditional conservation efforts to something more radical: artificial reproduction. Hagedorn, a marine scientist with the Smithsonian Institution, is building the world’s largest repository of coral sperm (and soon coral eggs and embryos) in hopes of one day reconstructing species from scratch and replacing what we’ve lost.
To some, that might seem like an ambitious and perhaps unnecessary undertaking. But Hagedorn, who’s based in Hawaii, argues that coral reefs play a special part in the ocean and require all the effort we can muster. For one, reefs are home to a quarter of all ocean creatures and help maintain biodiversity. They also provide people protection against coastal surges and boost marine tourism. The Great Barrier Reef alone is said to generate about $6 billion for Australia’s economy.
“If coral reefs fail around the world, we have no idea how that ripple effect will impact the rest of the oceans,” she says. “And healthy oceans are really important to our survival.”
Coral–a unique form of life that is part animal, part vegetable, and part mineral–is capable of reproducing both asexually and sexually. The simplest way is to snap off a piece and regrow it, like you were taking a cutting from the garden. But it’s not the best way, Hagedorn says. When you clone a plant, you’re simply reproducing it as it is, not breeding it in some new genetic form that’s potentially better.
“You can get more coverage, but you can [run] into problems, especially if diseases break out. One disease can devastate all the work you’ve done,” she says. “Having things that are produced sexually is often better, because you can throw the genetic dice and possibly a new adaptation will come along.”
For example, some years ago, staghorn coral fused with elkhorn coral to produce a new species called Acropora prolifera, which is now prevalent in the Caribbean. That’s good, because the hybrid is more heat-tolerant and surge-resistant than either of the varieties would be on its own.
Hagedorn has frozen the sperm of 11 coral species so far, scooping up reef spawn in Hawaii, Australia, and the Caribbean. She plans to capture another four this summer. In most places, the spawns happen only once a year, after a full moon, which doesn’t provide much of a window.
She can already use the sperm to cross-pollinate eggs in the water and increase diversity that way. But the larger goal is to grow coral in the laboratory using prefrozen versions of all the materials required. That includes eggs and embryos, and algae, which play a role in managing the environment where coral live. Hagedorn hopes to start freezing eggs this summer using a new technique borrowed from human clinics.
“There was a leap in technology with human eggs. We can now freeze 90% or greater. Ten years ago, it was less than 10%. We recently applied the same technology, and it seems to be working,” she says.
That’s not to say we shouldn’t also protect fragile coral systems by, for example, promoting responsible tourism. But Hagedorn’s work could offer an insurance policy. If all else fails, we should have her banks of reproductive material to fall back on.