Bleached Coral Reefs Bounce Back
Bleached and dying coral reefs are often held up as proof that global warming is laying waste to Earth's ecosystems. Now come reports that a number of reefs around the world are being brought back from the dead by dedicated oceanographers and conservationists. “The results are more than just promising; they are beautiful,” says Baruch Rinkevich, a marine biologist at the National Institute of Oceanography in Haifa, Israel. But how can these reefs recover in the face on ongoing global warming? Either global warming has reversed course or the bleaching of reefs wasn't due to global warming in the first place.
In Jamaica, the Philippines, Japan, Singapore, Thailand, and Zanzibar people are busy rebuilding reefs that have seen better days. Mineo Okamoto, a specialist in marine assessment techniques at Tokyo University of Marine Science and Technology, has been working to restore Sekisei Lagoon in Japan's Okinawa prefecture. Back in 1993 this remote coral lagoon was in pristine condition but, according to a report in Science, “Okamoto sensed that change was coming from global warming, with its threat of more-frequent bleaching events, and rising ocean acidification, which is caused by the uptake of carbon dioxide from the atmosphere and weakens corals.”
In 1997 and 1998 an El Niño followed by a La Niña warmed the eastern Pacific to the point that the algae that live symbiotically with coral deserted their hosts. Without the zooxanthellae algae to provide nutrients coral colonies starved and bleached out. The 1997-98 El Niño event, which lasted for over a year, also produced record-high sea surface temperatures throughout the Indian and western Pacific oceans, which caused some of the most extensive coral bleaching ever seen. The bleaching event killed an estimated 16% of corals worldwide (see “Warmer Waters More Deadly to Coral Reefs Than Pollution”).
Bleached coral. Photo OAR/National Undersea Research Program.
Sekisei Lagoon's northern edge was hit hard. But the interior and southern rim suffered only minimal damage, which enabled coral to recolonize bleached sections without human intervention. To help the damage portions of the lagoon recover, Okamoto has been placing grooved ceramic disks in locations where they can serve as shelter for coral larvae when the reef corals spawn. Once the immature coral starts growing on the disks, they are used to recolonize damaged portions of the reef. Around the world similar efforts at reef restoration are underway with promising results (see “Bringing Coral Reefs Back From the Living Dead”).
While we can all applaud the efforts of conservationists like Okamoto, something seems out of place here. According to the climate change crowd, global warming was supposed to be an unremitting march to destruction—an ever warming climate bringing with it scorched lands and ravaged oceans. How is it that more than a decade after the big bleach-out in 1998 the reefs are recovering, many on their own (see “Heat-resistant Corals Ignore Climate Change Threats”). The article in Science directly blames human activity, sediment and El Niño for the coral's plight, with references to global warming tacked on at the beginning and the end. This leads to the conclusion that global warming is mentioned more out of reflex or political correctness than any true causal relationship.
Since the publication of a paper in the Journal of Geophysical Research, which found that the El Niño-Southern Oscillation (ENSO) is a key indicator of global atmospheric temperatures, more and more scientists are questioning the IPCC global warming dogma. Chris de Freitas, a climate scientist at the University of Auckland, John McLean, of Applied Science Consultants in Victoria, and Bob Carter, from the Marine Geophysical Laboratory at James Cook University, found that combining the ENSO with the effects of sporadic volcanic eruptions accounted for 80% of recorded global temperature change in recent decades. CO2 and other anthropogenic global warming forcings become bit players on the global scale.
ENSO temperature variation, note the spike around 1998.
“The surge in global temperatures since 1977 can be attributed to a 1976 climate shift in the Pacific Ocean that made warming El Niño conditions more likely than they were over the previous 30 years and cooling La Niña conditions less likely” says corresponding author de Freitas. Those who study coral directly attribute the bleaching of reefs to ENSO moderated temperature changes, so why throw in a reference to global warming? Perhaps to garner more research funding or to curry favor with the climate change establishment.
Why do ecologists and conservationists always blame humanity for any change in the environment, particularly destructive change? It is because they have a myopic view of nature, believing it to be static and unchanging. The only way to explain disruptive change in their world view is to blame humanity. But that is not how nature works. To quote from Dr. Roy Spencer:
They can not conceive of nature changing all by itself, even though evidence of that change is all around us. Like the more activist environmentalists, their romantic view of a peaceful, serene natural world ignores the stark reality that most animals on the Earth are perpetually locked in a life-or-death struggle for existence. The balances that form in nature are not harmonious, but unsteady and contentious stalemates.
Nature visits all manner of destruction on its creations: floods, hurricanes, forest fires, tsunami, and mud slides caused by torrential rains. And these are just the most common, add earthquakes, volcanoes, ice ages and the occasional rogue asteroid. Change happens in nature, often violently, for without desolation there can be no renewal, no empty niches for new species to evolve into. Hardship is nature's perpetual gift to every living thing.
Yes, temperature can and does cause coral bleaching, but that doesn't imply global warming. If science wants something that can plausibly be blamed on increased atmospheric carbon dioxide, acidification seems a more likely contributing factor. No doubt other human activity also harms the notoriously sensitive coral reefs as well. But think about this for a moment—coral became the primary builders of ocean reefs sometime after the Permian-Triassic Extinction event some 251 million years ago. Since then they have weathered a number of other lesser extinctions and episodes of rapid global warming. Ice ages and warm periods have come and gone and the coral reefs remain.
In fact, Paul Blanchon et al. have published important new research on “Rapid sea-level rise and reef back-stepping at the close of the last interglacial highstand” the journal Nature. Investigating ancient coral beds in the northeast Yucatán peninsula, Mexico, researchers claim to have documented a period of rapid sea-level rise—a catastrophic increase of more than 5 centimeters per year over a 50-year stretch. This occurred around 121,000 years ago during the Eemian interglacial, the warm period before the last glacial onslaught. The sudden increase in sea-level resulted in the death of the existing reef because the sea rose too fast for the coral to build their foundation up toward the surface. Once the sea-level stabilized again, the same group of corals established a new reef farther inland and 10 feet higher in elevation, a process known to geologists as backstepping.
The Eemian was some 2°C warmer than current global temperatures and clearly coral managed to avoid extinction under those conditions. In the larger scheme of things, coral is able to roll with the changes, adapting to new conditions, something mankind should take note of. This is not to say that any individual coral or reef is immortal, clearly they are not. Though some researchers may refuse to believe that nature would harm the creatures they love, the periodic devastation of reef ecosystems is just another part of nature's cruel cycles. As an outcome of global warming, bleached coral is a red herring.
Be safe, enjoy the interglacial and stay skeptical.
help save the reefs.