Meet the Speakers: Dean D'Elia
Christopher D'Elia joined Louisiana State University in 2009 as Professor and Dean of the College of the Coast and Environment. D’Elia was part of the landmark Symbios Expedition to Enewetak Atoll in the Marshall Islands in 1971. The team conducted the most comprehensive study of coral reef undertaken until that time. He will serve as panel moderator for the Coral Reefs in Crisis event on March 1-2.
1. When did you first fall in love with coral reefs?
I got into corals during my graduate school years at the University of Georgia when I was looking for a major professor. I approached Professor Robert Johannes, intending to work on the estuary off the coast of Georgia. He was a gifted intellectual and wonderful professor, but he said that he had stopped working on the Georgia coast because he got a new NSF grant to work on corals. However, he did need a graduate student, if I wanted to work with him on that project. I’m no dummy, so I said, “Yes, of course!”
In the summer of that year, we flew out to Hawaii for the project. Before long, we ended up snorkeling around Coconut Island and I was just amazed at the beauty of the coral reef. At the time, it was a very distressed coral reef because of pollution issues but nonetheless was still a very impressive place. My love for reefs grew stronger as I got to see more spectacular places. Reefs are, in my view, more beautiful than any other ecological system on this earth. There is something mesmerizing about the beauty of a coral reef. It’s absolutely stunning.
2. What do you consider to be the most important aspect of your work? What is most important for the public to know about it?
My coral reef research was, at one time, fairly obscure. In the 1970s-80s, I was interested in the nutrition of corals. Most corals have these algae called zooxanthellae in their tissues that seem to enable the corals to do things that plants will do. They will take an inorganic fertilizer, like nitrogen or phosphorus, and actually suck it up in very low concentrations. And, they seem to be able to utilize it. In my work, I showed irrefutably that there is a definite uptake by the coral and the zooxanthellae seem to be mediating it.
Scientists have found that the flow of water is very important. This is from lots of studies. We found that coral reefs are able to fix nitrogen, which means they can take atmospheric nitrogen and make it into a usable form. They’re making materials that they survive on. We found that corals are able to hold on to minute amounts of nitrogen and phosphorus, take it out of the water, and then retain it. The nitrogen gets distributed to various parts of the coral like in enzymes, muscles, DNA, and RNA. It’s the same as fertilizing a garden. You’re taking an inorganic substance and it becomes internalized to make up the bio mass of the plant.
All of a sudden, as the current concern about the destabilization of coral-algal symbiosis due to rising temperatures grew, knowing a lot about how corals thrive and how they obtain nutrition became very relevant.
3. What do you think is the most critical or immediate impact coral reef loss would have on humans?
Sea level is rising all over the world and we also have areas of subsidence, which means sinking of the land. When you go to an atoll, for example, they will be subject to all these things. They are sinking at a very slow rate. And then, the actual sea level itself is going up due to thermal expansion. It’s like being on an elevator in a high rise building. Pretend you are going down and there’s a flood outside and the water is going up inside. That’s really what’s happening. We’re on that elevator.
If you live on an atoll, the corals and other calcareous organisms, those that make rock from seawater, are important in raising the bottom of the atoll against relative sea level. In general, the average sea level rise is something like 3-5 mm a year. Corals, in some cases, can obtain 10 mm a year, but not very easily. So, we’re quite concerned about the rate of relative sea level rise exceeding the ability of coral reefs to accrete and grow vertically, which protects atolls from the dual problem of sea level rise and subsidence.
Also, I would say that while coral reefs are not extremely productive for fisheries purposes, they nonetheless do provide important subsistence fishing for indigenous populations and thus are an important source of protein.
And, climate change and CO2 are not the only threats to coral reefs. “Death by a thousand cuts” is also a concern. By that, I mean that countless environmental impacts at the local level are cumulatively having very damaging effects on reefs all over the world. Collectively, local “insults” to reefs have global impacts.
4. What are the three most important things you think students who want to study corals should know?
I think they need to have an appreciation for general ecology because they need to put coral reefs in context with the other ecosystems that we have on the planet. We learn a lot from comparing and contrasting different systems.
Second, I think they need to have an appreciation of the critters on the reef and, in general, a broad understanding of what goes into the biodiversity of a reef. These days, not as many students are interested in botany, zoology or microbiology courses that you really need to fully understand these things. But, that’s important.
Lastly, I think it would depend on what the student is interested in studying. It should be special to them. If they’re interested in nutrients, as I was, they must have an appreciation of biogeochemical processes that are involved in nutrient cycling. If they’re somebody interested in fisheries, they have to have an appreciation of population dynamics, stock assessment, and so on. That drive to understand the fine details is so important in furthering your studies and developing your expertise.