Coral - January/February 2010

If there is a canary needed for the treacherous mine- shaft of global climate change, there may be no better aquatic candidate than corals in the genus Acropo- ra. As many of us know from personal experience, these corals are exquisitely sensitive to changes of water temperature, light, and water chemistry. Thin- skinned, they nevertheless dominate the stony coral heirarchy in the wild, growing rampantly when the conditions are favorable, choking out would-be competitors, and building coral reef structure at a furious pace. We love them for growth habits, diversity of form, and often spectacular hues.

During warming episodes, however, they are among the first to bleach, along with the Pocilliporids, while corals with thicker tissue layers are better able to weather the heat.

The Acroporas most of us buy and keep these days are daughter colonies or fragments from maricultured corals, and we have come to accept that to lose one is not exactly equivalent to having a Giant Sequoia fall at our feet. Nonetheless, it’s fair to say that most of us are dismayed to see even a single coral bleach or lose its tissue while under our care.

Imagine the pain of a passionate coral biologist such as Dr. Ove Hoegh-Guldberg, who has assumed the task of documenting bleaching events in the wild, watching with increasing frequency as acres of formerly healthy stony corals turn stark white on the Great Barrier Reef, the largest animal-built single structure on earth and a haven of biological stability for thousands of years.

LARR Y P. TACKE T T | TACKE T T & TACKE T T PRODUC TIONS

With these unprecedented bleaching episodes in mind, we are honored to present a new article from Dr. Ove, as he is affectionately known to his staff at the University of Queensland in Australia. As the coauthor of the single most-often cited research paper on the mounting biological effects of climate change, he presents both a sobering and upbeat message in a new article, Saving the Mothership, starting on page 42. If society ignores what is happening on the world’s reefs, he says, the outcome is almost certain to be chilling: these incredible structures with untold hundreds of thousands of marine species still to be discovered will be gone in our own lifetime or the lifetimes of our children.

As illustrated by the first Letter to the Editor in this issue, sent to us in anticipation of his article, Dr. Hoegh-Guldberg’s message will be hotly contested by some. We happen to think that a full and open debate about the facts of climate change is healthy, although the whole

At Wakatobi Marine Park, Indonesia.

issue is a morass of misinformation and complexity. The
internet is awash in quasi-scientific denials of global
warming, but the fundamental facts are irrefutable:
• Nine of the 10 hottest years in human historical re-
cords have occurred in the past decade. Energy output
from the sun has not increased in the past 30 years,
but warming trends have seen the steepest increases
ever recorded (Goddard Institute/NASA).

• Since the 1970s, the world’s oceans have steadily warmed at all depths studied 0-300 m, 0-700 m, and 0-3,000 m. According to the Pew Center on Global Climate Change, the observed results include sea level rise, coral bleaching events, loss of sea ice, intensification of hurricanes, and higher coastal storm surges.

• Carbon dioxide, which traps heat within the earth’s atmosphere, is at its highest levels in 650,000 years, according to the American Association for the Advancement of Science. Human fingerprints are all over this statistic, and for the majority of credible scientists, it is the smoking gun explaining what is happening to the earth.

However unthinkable it is, the spectre of losing coral reefs forever is something we, as marine aquarists, need to face, and Dr. Hoegh-Guldberg’s message is worthy of our full attention. We may not all share the same politics or environmental views, but we know what we love and it behooves us to be mindful of what’s happening to aquatic ecosystems and to do whatever we can in our personal lives to change the fate of the reefs.