Coral Triangle hosts dazzling web of life: mangroves and fireflies

WWF 12 Jun 12;

WWF’s Coral Triangle Director Catherine Plume recounts her incredible evening during a firefly river cruise in Donsol, Philippines:

"I arrived at the riverside just at dusk. The world was already casting its magical evening spell. As we pulled away from the pier, we fell captive to the tranquility of the night. Heading upriver we nestled into our life jackets and left the city lights behind.

The night itself was spectacular – no moon, a million stars, the hush of the river with only the sound of the sputtering motor as we glided along. Soon we cut power and our boatman poled us toward shore.

As we neared the riverbank, I began to discern a faint twinkling in the trees. The flashing became more intense until it became a swirl of tiny rotating lights – fireflies! But, these were like no fireflies I’d ever seen: flashing both on their own and also together. The sight was mesmerizing – like watching a string of tiny white Christmas lights dance dizzyingly. As you looked up into the trees, it was hard to tell stars from fireflies. As if anticipating our desire to see them closer up, more than one firefly broke away from its dance and flew toward us.

As we marveled at the firefly dance, our boatman softly said, “Now put your hand in the water”…and we did, expecting just to feel the river’s warmth compared to the now chilly night air. But instead, we were met with yet another treat – a bioluminescence created by our fingers as they moved through the water.

The impact was immediate. We spoke in hushed tones – but not much at all – not wanting to scare away the exceptionality of this moment. Our boat moved slowly upriver to an even larger swarm of fireflies. We marveled again at the sheer beauty and let our eyes go from the stars to the fireflies to the glowing water trailing our hands.

After a while, the boat turned around and we headed back toward the light of the far off bridge and pier. It was an oddly melancholy trip back down the river, and I had a sense that I was leaving behind something very special that I really wasn’t sure I would ever encounter again. A trifecta of nature’s sparkledom left twinkling on the river.”

The fireflies Cathy witnessed congregate in huge colonies to feed in mangrove trees along the riverbanks. Mangroves keep the rivers healthy and release important nutrients into the water. These nutrient-rich waters feed microscopic plankton, which create the bioluminescence Cathy observed. Out where the river meets the bay of Donsol, large masses of plankton can be found. These attract hungry whale sharks, which gather in schools to feed on the plankton.

Donsol attracts huge numbers of whale sharks compared to other places in the world, and locals benefit from the booming tourism industry. WWF has helped with whale shark tourism since 1998, which has created jobs and provided a seasonal but steady source of income.

In 2011, WWF spearheaded an effort to plant 10,000 mangrove seedlings to enhance and protect habitat shared by fireflies and whale sharks. By restoring mangrove forests, WWF keeps rivers healthy, ensures habitat for fireflies and food for whale sharks. In turn, fireflies and whale sharks attract tourists – just one way WWF is working to create harmony between people and nature.

Fireflies light up the forest as whale sharks dazzle in adjacent waters. How fitting that the markings of the whale shark almost perfectly mirror the twinkling of fireflies against the black night sky.

as told to Molly Edmonds, WWF-US