Tiny Survivors: Slivers of Hope in Dying Coral
More than 90 percent of the Great Barrier Reef, the world’s largest living structure of coral that extends more than 1,400 miles along the east coast of Australia, has been devastated by bleaching. Some scientists think a few more years of warm acid water will turn the great reef into eroding banks of rubble. And 2015 marked the third and biggest bleaching event in coral reefs world-wide.
But exceptions exist. In several places, tiny pieces of baby coral are surviving the adversities causing massive damage and destruction of most of their kind. Climate change and El Nino have raised ocean temperature beyond the tolerance of many coral species. Fossil fuel emissions are making the ocean more acid, and corals needs alkaline waters to thrive. Over fishing kills, because because corals depend on fish to nibble away the algae that compete for their space. Marine scientists are trying to discover how some coral varieties survive while others don’t.
In a New Yorker article, the Pulitzer Prize wining environmental writer Elizabeth Kolbert tells the story of Ruth Gates, a marine biologist who is doing survival experiments in her lab after studying coral all over the planet. She thinks if scientists can identify qualities that made some corals hardier than others, it might be possible to produce tougher varieties of corals. In this way, Kolbert writes, humans might be able to “design reefs capable of withstanding human influence.”
In 2013, a foundation run by Microsoft co-founder Paul Allen held a contest called Ocean Challenge, which asked scientists to present plans to counter rapid change in the seas. Gates, director of the Hawaii Institute of Marine Biology, and an Australian collaborator won $4 million to create a “super coral.” Kaneohoe Bay, used as a sewage dump for much of the 20th century, was their inspiration for the project. After an invasive algae fouled the water, environmentalists at the University of Hawaii and the nature Conservancy devised something like a huge marine vacuum cleaner to suck algae off the seabed. Gates was fascinated by the corals that survived all this adversity. In her labs, she’s experimenting to find which corals survive combinations of warmth, acidity, pollution and sparse fish populations—the conditions they’ll face in the ocean of the future. The most successful offspring will be bred with each other to see if future generations can be even more robust.
Selective breeding of animals has already produced meatier chickens, cows and pigs and allergy resistant pets. Selective breeding to thrive within a changing ecosystem ranges pushes new territory, Kolbert writes, but there is already a name for it: assisted evolution.
Individual corals are known as polyps, are tiny organisms that collectively constitute a thin layer on the surface of a reef. The underlying structure is essentially a bone yard of earlier generations of corals. The organisms living in the coral polyps give coral its dramatic colors. When they die the coral is bleached white.
Gates not only wants to discover what makes some coral varieties more robust. She wants to know whether the more vulnerable varieties can be “trained” for better survival. Corals are inhabited by a multitude of other tiny creatures, called symbionts, which seem to have differing tolerances to heat and other adversities. Gates wonders if corals might be encouraged to take up new symbionts, just as parents urge their children to make new friends. Or, some differences in survivability could be epigenetic, meaning they are influenced by experiences of earlier generations. “Epigenetic is to genes what punctuation is to prose,”Kolbert writes. “Epigenetics alter the way genes are expressed, but leave the underlying code unaffected.”
Even if Gates and other research scientist can produce a super coral in the lab, some scientists Kolbert interviewed doubt such successes could be taken to scale. But as Gates tells Kolbert, even if it doesn’t immediately work, it’s important to try because changes to earth and is waters aren’t going to stop.