This is the first in a series of posts from our AtKisson group intern, Niak Sian Koh, who has been volunteering at a sea turtle conservation project on an island off the east coast of Malaysia.
We begin our journey on the northern side of Tioman Island, in a little village called Salang. The bay just outside Salang Beach is rich with coral reefs and marine life; swim a short way off the beach and you’re hovering over dense, brightly colored corals, with a rainbow of fishes nibbling away at the algae coating the reef.
In between the reefs, however, there are pockets of white corals. They have bleached out and lay broken on the ocean floor. Our dive guide, Xyman Bakri, is a laid-back guy who always has a wide grin on his face. He tells us about the most recent, massive coral bleaching event: “The ocean waters here should be 28 to 29 degrees Celsius [about 82 to 84 degrees F.—Ed.] for the marine life to thrive. Four years ago, we had a massive heatwave where the water was 31 degrees [87.8 degrees F] for about three months. We lost 70 percent of our corals in the cove then.”
What exactly is coral bleaching?
Corals look to the human eye like plants, but they are, in fact, invertebrate animals. The bright colors we associate with corals actually come from the algae that they host in their tissues. The two species depend on each other to survive: in return for the home base that corals provide, the algae produce carbohydrates through photosynthesis, which nourish the corals.
If unfavorable conditions stress the corals, they expel the algae and turn completely white, or “bleach.” Stress factors include extreme temperatures, pollution from agricultural runoff, changes in the salinity of seawater, and excess sedimentation from sand dredging.
Bleached corals can survive and recover if the stress-caused event is not severe. But if the stress continues over time, the coral will eventually die.
“Corals do have a natural life cycle. They can live from decades to centuries,” says Xyman. “The corals are rather resilient to heat shocks, if the warm temperatures are not prolonged the reefs can recover by themselves in a few years.”
One open question is how frequent underwater heatwaves will become as average global temperatures continue to rise. Another is how to cope with these changing conditions, and on Tioman Island, the villagers of Salang, who depend upon ocean tourism as their main source of income, may have found one answer, by giving their local reefs a boost that may help them continue to host marine life in the cove.
The first step involves assembling PVC pipes on land, in a rectangular structure, with small live corals attached along the pipe using plastic zip ties.
Divers come together to sponsor the project and bring these pipe structures down to the ocean floor. Left to grow, the corals will slowly but surely form a new reef over a few years.
Coral reefs are like the rain forests of our oceans: Although they inhabit a very small percentage of the ocean floor, they are host to 25 percent of the marine life. They provide coastal protection, as well as being a main source of food and tourism to the locals. As Xyman aptly puts it, “No corals means no marine life.”