Clare Fieseler is a National Geographic Young Explorer, NGS Waitt Grantee, and a Ph.D. candidate at the University of North Carolina-Chapel Hill. Since 2009, she has conducted field work on coral reef ecology, climate change, and reef conservation in the Caribbean. In fall 2015, she’ll be a fellow at the Smithsonian Tropical Research Institute in Panama. When not doing research, Clare is a freelance science reporter for public radio and other outlets. Clare wrote this wonderful post about her work!
I always looked forward to my dad stacking new logs on the backyard woodpile each fall. Like so many other kids, I was bewildered that things from the past, like tree growth and weather, were visibly locked there in the wood. I would sit and count rings, size up logs, and try to find the oldest tree. Little did I know that my scientific career would not be much different. (Except, of course, for doing it underwater with 80 pounds of hydraulic hoses.)
Climate change has upped the stakes of this ancient ring-counting science, called dendrochronology. Today, with some engineering feats and computerized x-ray technology, coral biologists like Dr. Karl Castillo can decipher the bands found in corals just like botanists study tree rings. In a recent Google Hangout for National Geographic Learning, Dr. Castillo and I demonstrated how century-old coral skeletons can provide important clues for predicting the condition of coral reefs in the far-off future.
The Smithsonian Tropical Research Institute in Bocas Del Toro, Panama, was where we started this coral coring project. (It’s one of the largest ever attempted!) Our research team just finished the second leg of our field work in Panama. More than sixty extracted cores sit packed in metal containers, the result of 8-hour days spent underwater with a hydraulic drill and careful remediation tools. Dr. Castillo manned the drills while the team tagged colonies, collected DNA, plugged up the holes, and measured ocean conditions. It is physically demanding work. “My whole body aches,” joked Dr. Castillo on his first day off.
And that’s his style: always positive, all smiles, and supremely ambitious. Having grown up in a sleepy coastal town in southern Belize, Dr. Castillo knows the Caribbean reef environment better than most. He also knows how fast it is changing. The elements he wants to tease apart are how fast corals grow in relation to ocean temperature, although other factors like ocean acidification and nutrient inputs are also considered. In the Caribbean Sea, average temperature has been slowly increasing, following global climate change trends. And, at the same time, coral growth is mostly slowing. In short, carbon emission might be stunting coral growth, undermining the most important process for thriving coral reefs.
“I truly believe this research will be transformative,” says Dr. Castillo. His past coring research from Belize suggests that some species—in some pockets of the Caribbean—might be able to naturally acclimate and grow despite the coming onslaught of climate change. So expanding his research to other species and other countries helps uncover if this natural capacity is widespread enough to give region-wide hope for the Caribbean’s reefs.
Never before have so many cores been collected under a single project. Why so many? “There is a scientific reason and a much more simplified reason,” says Dr. Castillo. First, the existing science says that to get any statistically significant conclusions about past ocean history from a coral skeleton, our team needs to collect a certain number of cores per reef system.
This approach captures the entire cool-to-warm temperature range of Caribbean coral species. When it comes to climate change research, information from the past, from today, and from an animal’s species range can say a great deal about the animal’s future in forecasted climate scenarios. Dr. Castillo believes the transformative nature of this research lies in this range-encompassing and multi-scale sampling design. As conservation efforts for Caribbean corals become more coordinated with governments and organizations around the region, this approach might be the future for both conservation and research alike.
What’s occupying us now is the task at hand: getting our cores and 1,000 pounds of equipment back to the United States. In this tropical landscape, it’s easy for me to slip back into the wonder of counting tree rings in the backyard. Seeing that same activity underwater, with adult eyes and the urgency of modern climate change problems, it reminds me that some sparks of curiosity remain with us.
Fostering those sparks when we recognize it in kids and students is one of the most important things we can do. Thank you to all the educators who do this every day! You can follow the Castillo Lab and our work on Twitter and Instagram. This research is funded by the National Science Foundation.