Raising Coral

By Steve Friedman

Imagine you’re swimming lazily along, just below the water’s surface in a tropical ocean. You look down at a colorful array of pinks, yellows and greens. Spikey corals cover the floor below. Small fish swim in and out of hiding places, ducking behind the stationary animals to avoid your peering eyes.

You emerge from the water. The air is warm, and humidity surrounds you like a blanket. But instead of a blue sky, you look around and see gray walls, pipes, strings of LED lights, ceramic tiles and white buckets full of sea salt. There’s a low hum of water pumps, and the room glows fluorescent blue.

This is actually Eli Meyer’s research lab at Oregon State University. You were drifting in the 10-foot long fish tanks where Meyer and Ph.D. student Katie Dziedzic study how coral are adapting to the changing oceans.

Hobbyists have been growing coral in saltwater aquariums for decades, but the idea is just catching on with coral researchers. “Historically, coral research has relied on field work, which is incredibly limiting. More recently, many of us have turned to growing corals in lab aquariums.” says Meyer.

This approach allows these researchers to do the kind of controlled studies that are much more aligned with research in biomedical labs. Dziedzic is directly comparing nine coral species and measuring which genes are changed under different temperature, salt and acidity conditions. Experiments that used to take several years can be done in several months with this setup. This is a critical advance, since the world’s coral reefs are disappearing.

Oceans help to absorb about 90% of the world’s heat. This seems like great news for most of us, but warming oceans contribute to devastating bleaching events among the world’s coral reefs. When corals “bleach,” they kick out the colorful algae that normally provide the corals with food. Not only does bleaching mean the coral won’t look as pretty, but it has serious health effects for coral species as well as the ocean biodiversity corals support.

When healthy, coral animals live together with algae that grow all over their exterior. The algae provide nutrients and beautiful color to their coral hosts. In return, corals provide algae with some of the ingredients for photosynthesis.

During stressful events, like a spike in ocean temperature, algae produce toxins that corals don’t tolerate. As the Earth’s climate warms and the ocean has to absorb all that heat, mass bleaching events are becoming more common. The corals are turning into ghosts at an alarming rate.

Staring into the fluorescent blue water in their coral tank, Dziedzic and Meyer contemplate what the future holds for these animals. While the ocean environment changes uncontrollably, some corals are learning to adapt. These species may hold the key to survival, and humans may be able to assist by transplanting resistant corals to dying reefs.

Lab coral research programs, like the one at Oregon State, may help in this pursuit. At least one species, called the golf ball coral, can now be bred in captivity. The OSU researchers are showing that it may be possible to breed resistant corals and transplant them into the wild. For now, this idea is still a long way off.

You may not be able to swim in the coral tank, but you can see a live webcam of the tanks and check it out for yourself. Dr. Meyer keeps, and posts lots of amazing photos and stories about the lab’s research. The corals also love visitors!

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Editor’s note: Steve Friedman is a Ph.D. student in Biochemstry and Biophysics at Oregon State University.