National Geographic Explorer Erika Woolsey talks about her work as a marine biologist and coral reef specialist, sharing the study of ocean science with Chautauquans through educational resources and films Monday in the Amphitheater.
Erika Woolsey took the Amphitheater for a deep virtual dive into the ocean and across the coral reefs Monday morning for the Chautauqua Lecture Series theme of “Water: Crisis, Beauty and Necessity — A Week in Partnership with National Geographic.”
Woolsey, who is a marine biologist, coral reefs specialist and National Geographic Explorer, is the chief scientist and CEO of The Hydrous — a nonprofit organization that aims to make ocean science more accessible and easy to understand for the public.
With audio and visual elements, Woolsey brought the ocean to Chautauqua, as she showed close-up images and videos of the Great Barrier Reef and the sea life around it, explaining how its ecosystem works.
Erika Woolsey opened Chautauqua Lecture Series Week Eight, “Water: Crisis, Beauty and Necessity — A Week in Partnership with National Geographic.”
“Even though corals might look like plants and rocks, they’re actually animals. They’re marine invertebrates, … a bunch of individual polyps coming together to create a larger structure,” she said. “Each polyp has a single mouth in the center with lots of stinging tentacles, similar to the body structure of an anemone or a jellyfish, which are its cousins. And corals are really talented organisms — when they band together, they have this remarkable ability to build sprawling empires.”
Woolsey went on to show a diagram of a polyp, detailing the process in which corals exhale carbon dioxide, and how some of that CO2 bonds with calcium in the water to create calcium carbonate, which builds a reef. She explained how, one layer at a time, a reef begins building its skeletal home, with what is called a corallite — the building block of an entire reef.
“A coral polyp will spend its entire life living in this corallite and they can’t do it alone. Thousands of polyps are all doing this together, creating a coral colony,” she said. “In tandem, they slowly construct a complex structure that no individual coral polyp could do alone.”
When a polyp dies, neighboring polyps fill the space and new polyps begin to form on top of the old ones, meaning coral colonies can grow for centuries.
Part of why Woolsey has dedicated her life to studying corals and their life cycles, she said, is because they have the amazing ability to tell so many stories.
The Great Barrier Reef structure is home for thousands of other animals, many of whom reproduce on the reef. Some animals come to the reef to hunt, while others live in the crevices the reef has to offer. Woolsey highlighted the importance of some “destructive” species, such as the parrot fish, who break down the rocky coral foundation.
With their beak-like teeth, parrot fish break off chunks of hard coral to eat algae, helping the coral get rid of excess algae that can suffocate the reef. This helps the reef grow stronger, because the exposed area is prime territory for new coral polyps to settle on. With the teeth inside their throats, parrot fish break down coral chunks that are later excreted as calcium carbonate, more commonly known as sand.
“One parrot fish can create up to almost 200 pounds of sand per year,” said Woolsey as she showed the process on screen. “Just like the coral creates a home for thousands of species, the parrot fish lining the reef with sand creates another home for hundreds more. It’s just another thing that makes the Great Barrier Reef a really amazing place.”
Woolsey detailed a dive to one of the largest reef colonies on the Great Barrier Reef — so large it was visible from the sky — that measured out to be just under 30 feet wide and 15 feet tall, which meant it wasn’t even the largest recorded in the area.
“Finding the biggest or the oldest (reef) is always cool bragging rights, but it’s also important to scientists because that’s how we piece together the history of the reef,” she said.
She showed a picture of a coral ring sliced in half and put under a microscope, and a video of scientists drilling out a 2-foot cylindrical sample to x-ray and study. She explained how, even without the actual coral, 3D models can be helpful in determining certain information about the coral’s history.
Throughout her career, Woolsey has worked closely with VR technology, and 3D modeling, and she uses a special software that allows her to stitch hundreds of the two-dimensional images she takes during her diving excursions into digital 3D content in a process called photogrammetry. She can share those models with anyone, anywhere, virtually and digitally.
“From these images, co-researchers can really learn a lot — like how much rainfall there was in a given year, or what the PH or chemistry of the ocean was like,” she said. “When I entered the measurements I took underwater, like diameter and height, the software can calculate things like volume and surface area. From that, I estimate that this coral colony is about 400 years old. This means that (the colony) has survived 70 tropical cyclones and almost 100 heat waves, plus centuries of human impact. Talk about resilience.”
As Chautauquans continued their virtual dive with Woolsey, she shared some of the scuba signals divers use to signal certain things like, “I’m OK,” “let’s descend,” “let’s ascend,” and even some to indicate animals nearby, like turtles, sharks and clownfish. She also showed the equipment divers need to “become fish,” and their purpose. She explained how wetsuits keep divers warm and protect them from stings, how weighted belts counteract buoyancy, and how air tanks allow people to breathe underwater (and compensate for our lack of gills). With this, the Amp was fully equipped to embark into the dive.
As she showed a close-up of a coral colony, Woolsey detailed the symbiotic relationship with zooxanthellae — a tiny organism that gives the reefs its colors and most of its nutrients. In return, the zooxanthellae — also known as zoox — shelter inside the coral tissue, protected by the coral’s stinging tentacles.
“Without the single-cell algae, coral reefs as we know them would not exist,” she said. “The photosynthesizing algae makes sugar from sunlight, giving the coral about 90% of the energy it needs to grow, survive and reproduce.”
Cleaning stations are another one of the ocean’s many natural partnerships, and a place where many different predators and prey live in harmony.
“Cleaning stations are a permanent fixture on the reef, and they can sometimes last for generations,” she said. “At cleaning stations, predators take a break from hunting and allow smaller fish to nibble on and remove dead skin, bacteria and parasites from their bodies, gills and mouth. This keeps the predator’s skin clear and its organs healthy.”
As the “dive” ended, Woolsey reminded everyone that every species below the waves plays an important role in this diverse ecosystem.
“A healthy coral reef is truly magical, and as I mentioned when we started this journey, this entire ecosystem begins with the coral. But coral must be living in the right circumstances, and to understand, we need to go back to the coral’s relationship with its partners,” said Woolsey. “Remember, the zoox provides almost 90% of the coral’s food, and this pair generally thrives in water temperatures between 73 and 84° Fahrenheit. The problem is, we don’t live in an ideal world and all of the beauty we just explored is in danger.”
Changes in water temperature cause stress to the corals and the zoox, and living in this stress makes the algae produce too much oxygen, which is toxic to the coral. This causes the coral to expel their zooxanthellae, leading them to starve and lose their color, something known as coral bleaching.
“Sustained bleaching causes corals and whole reef ecosystems to degrade,” she said. “Since 1950, the world has lost about half of its shallow-water coral reefs, and since 1998, there have been about 10 mass bleachings on the Great Barrier Reef. Unfortunately, they’re becoming more frequent and more severe.”
In order to prevent the loss of these ecosystems, Woolsey and her team have begun collecting pregnant coral samples to research how baby corals react to stress, and make better predictions about the future generations of corals if temperatures continue rising.
Woolsey learned that warming oceans are not only causing bleaching events and affecting adult corals; they’re also threatening the baby corals, which affects the ability for a coral reef to replenish its populations and recover following disturbances. She believes that understanding these things will allow for better decisions and predictions to be made when it comes to protecting and encouraging reef recovery.
“A healthy reef is a place for babies to grow strong, like the black tip reef sharks you saw in the mangroves,” Woolsey said, referencing an earlier video. “It’s a place for animals big and small, like the clownfish, to live for generations.”
In closing, Woolsey reminded the audience of the beauty of the ocean and the importance of protecting coral reefs.
“I’m right where I’m meant to be: studying, exploring and teaching about coral reefs,” she said. “As a new mom, I recently brought my little family to Australia to experience the wonder of the Great Barrier Reef and witness the coral spawning. I hope that sharing these stories will help you appreciate our beautiful blue planet, so that together we can respect and preserve it for future generations.”
