Light is Life

I can see why people always get sunburned during the Bocas-ITEC station portion of our program. The sun at Bocas del Toro literally permeates everything we do; in the water, I can see reflections off the surface ripple through the corals, the sunlight frolicking with the sea creatures. The light creates a layer of texture and movement, adding to the camouflage of fish and crustaceans. Many creatures stay amazingly still—the scorpion fish is like another layer of sand, Flying Grenards seem to gently float through seagrass with the current, and the giant lobster is just another piece of coral. Fascinated by the graceful, slow movement of an octopus, or the ephemeral trail of a weaving puffer fish, I was completely immersed in simply trying to maintain my field of vision and completely oblivious to the hot, burning sun reflecting off my back.

            In class we’ve had the importance of sunlight drilled into our heads. Plants must have sunlight to grow and have thus developed all kinds of adaptations in order to optimize their amount of light exposure. For the forest we continuously talk about secondary growths, sun flecks, and light-gaps. But even back at La Selva, our invited faculty, Molly Cummings, talked about her research on countershading and sun reflection in fish. Fish, like aposematic poison frogs and plants, develop adaptations to survive and thrive in sunlight. I loved diving into the slightly deeper waters, which were murkier but more evenly dimly lit, and seeing large pieces of coral and bigger parrotfish coming in and out of the reefs. The lack of light hid a beautiful lionfish from my eyes, but luckily not the eyes of our invited faculty, Andy, and I kept diving down again and again to get a closer look.  The underwater world is completely different from anything I’ve ever experienced, and as I wrote my field notebook, I realized that I really lacked the words to sufficiently describe what I was seeing. The changing seascape, from the mangroves, the beds of seagrass, to the patches of coral reef, further changed with the different layers of light permeating the waters. Personally, I’ve always loved sunlight—the way it glances through leaves, the array of hues it creates at dawn and dusk, the glorious heat it brings—but as I stared captivated by the underwater kingdoms scintillating with patches of light, I understood just a bit more how sunlight is life for humans, plants and animals, and even the reefs and sea creatures.

Jeanne Shi

Duke University