Climate change is seriously endangering these richest reservoirs of marine biodiversity. Here is my story of some of these alarming changes.
My journey began in Cosmoledo (map), a remote atoll in the western Indian Ocean, 200 miles northwest of Madagascar and 600 miles west of the African continent. I first visited there in 1986 as part of a Smithsonian Institution expedition. I remember the reefs were teeming with lush coral growth and there was an amazing display of colorful reef fish. When I went back in 1999, the land looked very much the same, a beautiful white sand beach, palm trees swaying, and Tournefortia and Scaevola bushes embracing the shoreline. What an idyllic setting. It was great to be back, or so I thought. Then I donned my mask, snorkel, and fins to plunge into the warm waters. This time something was very different. The fish were there in abundance but the corals were all dead. There were a few isolated coral heads that had just begun to recover, but 95% of the reef was dead. The fish swam around looking for something to eat and for their old habitat. It reminded me of people returning to find their homes in ruins after a wildfire had roared through a forest. I was shocked at what I saw.
Here we were on one of the most remote atolls in the Indian Ocean, where only the occasional turtle hunter or fisherman ventures. There is no permanent habitation, only a few huts where people sleep when they are fishing or gathering coconuts. There is no pollution, virtually no resident human impact, and no local explanation for this profound decimation of a once-healthy reef.
This is when I had my first “aha" moment about climate change. For me it was real and catastrophic in what had happened to the reefs in the western Indian Ocean. From that day forward, I became convinced that the world's richest oceanic habitats, the coral reefs, are seriously threatened.
However, I didn't see more evidence of coral death in the parts of the Indian and Pacific Oceans where I was spending a couple of months each year studying the diversity of nudibranchs. Meanwhile, my colleagues in the Caribbean continued to report serious problems on their coral reefs. At the International Coral Reef Congress held in Okinawa in 2004, reef biologists reported that the changes in the dominant coral species in the Caribbean had not been replicated in the geologic core samples they made in the reef that went back through 4000 years of history. At this moment, I remember turning to one of my colleagues and saying, “this is incontrovertible evidence that something unprecedented has changed, and nobody can possibly doubt that this represents human-induced climate change." Read the full report here.
Source: Marine Research in the Indian and Pacific Oceans, by Dr. Terry Gosliner, Climate Story Tellers.
