For the latest ocean news, subscribe to Ocean Update and our other free newsletters.

Other Ocean Voices>>>

An Interview with Richard Aronson

Rallying Courage for Coral

"Be courageous and don't give up on coral reefs and the rest of the marine environment. ... There are some things going right."

What inspired you to research marine environments?
When I was nine years old, I was watching television late one night when I wasn’t supposed to be and I saw Jacques Cousteau’s movie “The Silent World” in grainy black and white film. I was hooked.

One of your focuses is paleobiology. What can the marine environments of the past tell us about those of today
Marine environments of the past provide us with records of how different types of communities responded to environmental change. We know that right now the environment is changing rapidly with global warming and its associated effects. If you can look at a similar climatic change in the fossil record and see how communities responded to say, increasing temperatures, then you can make predictions about how today’s communities will respond to the rapid shifts we are seeing now. For example, in the last 3,000 years, sea level has only risen about two meters [about six feet], so that is rather slower than what is predicted to happen in the future. If you look at what is happening now, it is already speeding up.

Richard Aronson investigates the effects of climate change on the ocean, from the tropics to 100 feet under the ice at McMurdo Station, Antarctica. Bill Baker

Have you witnessed differences in marine environments from when you have first studied them and now?
Absolutely. My first real serious marine biology experience with coral reefs was in Jamaica at the Discovery Bay Marine Lab. When I first went there in 1976, when I was a freshman at college, those reefs were completely covered with staghorn and elkhorn coral. Elkhorn coral is a stocky, treelike coral that lives at the top of the reef where it breaks through the water’s surface, called the reef crest, and staghorn coral lives on the fore reef, the part of the reef that faces the open ocean. There were huge fields of both of these corals, but when I came back in the late 1980s, those corals were gone. They were gone because of a combination of hurricane damage and an outbreak of a disease called whiteband disease, which is a bacterial infection that wiped out those two coral species not only in Jamaica but all around the Caribbean. Seaweeds have replaced these corals on a lot of Caribbean reefs.

This common sea star is an important predator on shallow seafloors in Antarctica. As the climate warms, crabs will be able to invade shallow Antarctic habitats and eat invertebrates, disrupting food webs. Richard Aronson

You have an interesting span of research, from corals in the tropics to invasive crabs in Antarctica. How do these opposing environments relate?
Both tropical environments and polar environments are especially sensitive to climate change. In Antarctica, if the climate gets warm, cold-adapted species have no place to go if they are in the marine environment; they can’t go further toward the South Pole because the Antarctica continent is blocking their way. So ultimately, they are going to be stuck. If it gets too hot, some tropical species simply are not going to be able to survive.

So what is it about coral reefs that intrigues you?
Oh, corals are beautiful! They provide structure to the ecosystem and habitat to all those wonderful fish. The whole package—the coral, the fish, the mollusks, the crabs, the giant clams, the other invertebrates that are running around—all that stuff is so spectacular. You can’t avoid loving it!

What are the greatest threats to corals today?
There are a variety of threats. The problem is always trying to disentangle them and trying to determine which threats contribute more to the decline of coral reefs than the others. Two threats, global climate change and disease outbreaks, are intimately intertwined. Rising temperatures cause corals’ symbiosis with single-celled algae to break down. They eject most of their algae and turn white, which is called coral bleaching. Without their symbiotic algae photosynthesizing, the coral animals cannot get the carbohydrates they need and they are basically ill with a noninfectious disease.

Infectious diseases like whiteband disease, which devastated elkhorn and staghorn corals in the 1980s and 1990s throughout the Caribbean, are another problem. A number of infectious diseases become more virulent as the temperature goes up. … These are very serious threats on a regional to global scale for coral reefs.

There are also many local threats, like overfishing, nutrient pollution, ship groundings and sedimentation from land clearing. If you clear forests, eroding soil runs down the rivers and falls onto the reef, and corals hate to have sediment dumped on them—it smoothers them.

White band disease killed staghorn and elkhorn corals throughout the Caribbean beginning in the late 1970s. Such a mass coral kill hadn’t happened for at least thousands of years. Richard Aronson

What does ocean acidification do to coral?
Ocean acidification is another aspect of our changing global environment. It potentially is as dangerous for corals and other calcifying marine life as rising temperatures. The more carbon dioxide that gets pumped into the atmosphere, the more it gets dissolved in the ocean and the more acidic the ocean gets. ... A more acidic ocean makes it more difficult for corals to build their skeletons, which affects their ability to build the reefs upward and keep up with rising sea levels.

Some scientists predict that if current trends in fishing, pollution and emissions continue, some coral reefs largely will be gone in the next few decades. Have we already reached a tipping point?
We have not reached a tipping point. But the window is closing. Now is the time to stand up and fight for the environment. This is not the time to hang it up and go home.

So what can we do for corals?
There are issues like fishing pressures and nutrient pollution that we can fix on a local to regional level. Then there are global issues. The primary global problem is the emission of greenhouse gases, which causes not only warming temperatures but ocean acidification as well. This is not an unstoppable problem. We need global, international action to mitigate and reverse the amount of greenhouse gas emissions. Nothing less is going to do it. This is the planet we are talking about. If we don’t act, then we aren’t going to make it.

Staghorn coral has recovered in some places, including this area of reef on the north coast of Jamaica. William F. Precht

You are President of the International Society for Reef Studies (ISRS). What is the goal of this organization?
The goal traditionally was to disseminate and promote coral reef science. Increasingly, we find ourselves in a position of advocacy. For example, we produce briefing papers on important environmental issues. We are starting a mentoring program for young coral reef scientists. We are looking into helping to design syllabi to accompany K–12 education to sensitize young children to environmental concerns. They are the generation that is going to face this crisis even more so than we are. Hopefully, we can stop this looming disaster, but who knows? They may experience an environment that is in deeper trouble than it is today.

What role does ISRS play in this year’s International Coral Reef Symposium (ICRS)?
We are cosponsors of the International Coral Reef Symposium, which is held every four years. It brings together coral reef scientists from all over the world to discuss science, make policy recommendations and think about what we need to be doing. The theme of this year’s ICRS is “Reefs for the Future.” It is meant to be a positive message, that there will be reefs in the future. There is no doubt that they will be somewhat different than when I was a freshman in college scuba diving at the Discovery Bay Marine Lab in Jamaica. But it is our goal and our obligation as stewards of the environment to do a good job—not just the best we can—but do a superior job in protecting these reefs and fixing them so they are functioning reefs for future generations.

What do you hope will come out of this particular meeting?
I think some scientists are already demoralized about the state of reefs and I want them to go away feeling positive, with the fight put back into them. That is my goal as President of the International Society for Reef Studies.

I think we need to look at what is going wrong with coral reefs, what is going right with coral reefs, what are good courses of action and what are not such good course of action. For example, the Florida Keys National Marine Sanctuary is zoned for multiple uses. There are zones that are no-take, zones for diving and boating, etc. ... This stuff works. If you go diving there, you are going to see a lot of herbivorous fish that eat seaweed. This provides space that allows corals to get in there and find areas to grow. So the ground is prepared for coral recovery, and now we have to attend to regional and global issues, which reach far beyond the boundaries of the Sanctuary.

The main thing that I would advise scientists, conservationists and the public to do is to take heart, be courageous and don’t give up on coral reefs and the rest of the marine environment. A lot of people get compassion fatigue, which is to say they are continually bombarded with what is wrong with coral reefs so they feel like giving up. But there are some things going right with reefs, both ecologically in terms of recovery of some coral populations, and in terms of conservation and policy initiatives.

If you are a scientist, manager, policymaker or concerned citizen, think for yourself. Formulate your own opinions, follow the science, read all you can about the issues and don’t follow the latest self-proclaimed ideological leader. Think about it all with a view as to what can we do to help save coral reefs.