WUWT has posted several excellent articles by Jim Steele on how global warming alarmism uses corals as the poster child for warming and acidifying oceans, none of which is scientifically justified. A brief review follows, calling attention to a recently discovered additional adaptation mechanism not covered AFAIK by Jim Steele’s posts. The motivation for this post was triggered by a recent lunch with newish neighbor Charles the Moderator (CtM), and his sharing many wonderful underwater photographs of the coral reef he now dives frequently off Pompano Beach (same reef system as off Fort Lauderdale, just a few miles further north and more conveniently onshore).
In light of the above findings, Coles et al. state the obvious, that the corals “were able to withstand elevated temperatures (31.4 °C) for a longer period of time in the current 2017 experiment” compared to the 1970 study. Consequently, they conclude that their results “indicate a shift in the temperature threshold tolerance of these corals to a 31-day exposure to 31.4 °C,” which findings “provide the first evidence of coral acclimatization or adaptation to increasing ocean temperatures.” And that observational reality should hold great bearing on the status and health of coral reefs in response to future climate change. If temperatures rise in the future, clearly, as living organisms, corals can (and do!) adapt. Alarmist predictions of their fast and ensuing demise due to global warming should not be taken too seriously.
For the study, published this week in the journal Restoration Ecology, researchers installed 11,000 small, hexagonal structures called “spiders” across 5 acres of reef in the center of Indonesia’s Coral Triangle. Coral diversity is the highest on Earth in that region but is threatened by human activity, including overfishing, pollution and climate change.
Between 2013 and 2015, researchers attached coral fragments to the structures, which also stabilized rubble and allowed for water to flow through freely.
A CORAL SUCCESS STORY
Live coral cover on the structures increased from less than 10 percent to more than 60 percent. This was more than what was reported for reefs in many other areas of the Coral Triangle, at a cost of about $25 per square meter.
Le blanchissement des coraux est un phénomène dont on entend souvent parler dans les médias. Il s’agirait d’un grave problème environnemental, dont la fréquence augmente, et qui pourrait mener à la perte totale des récifs coralliens. Le réchauffement climatique global, qui serait causé par l’augmentation de la concentration atmosphérique en CO2 est, bien entendu, pointé du doigt. Cependant, le blanchissement des coraux n’est-il pas un phénomène très ancien? Est-il seulement causé par des variations de température? Quel recul avons-nous à ce sujet? Une récente publication de Nicholas Kamenos et Sebastian Hennige, deux chercheurs anglais des Universités de Glasgow et d’Édimbourg, apporte de nouveaux éléments.
From the “science eventually self-corrects” department, new science showing coral bleaching of the Great Barrier Reef is a centuries-old problem, well before “climate change” became a buzzword and rising CO2 levels were blamed.
Marc Hendrickx writes:
New paper shows coral bleaching in GBR extending back 400+ years.
UM Rosenstiel School-led study exposes two threatened corals to future climate change conditions
MIAMI—New research shows that not all corals respond the same to changes in climate. The University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science-led study looked at the sensitivity of two types of corals found in Florida and the Caribbean and found that one of them—mountainous star coral—possesses an adaptation that allows it to survive under high temperatures and acidity conditions.
“Stressful periods of high temperature and increasingly acidic conditions are becoming more frequent and longer lasting in Florida waters,” said Chris Langdon, marine biology and ecology professor and lead author on the new study. “However, we found that not all coral species are equally sensitive to climate change and there’s hope that some species that seemed doomed may yet develop adaptations that will allow them to survive as well.”
After half a billion million years of climate change, I’m shocked, shocked I tell you, that life on Earth (and specifically corals) have so many ways to cope with the climate changing. After all, it’s natural (if you are trained by Greenpeace) to assume that corals can only survive in a world with one constant stable temperature just like they never had.
One more tool in the coral-reef-workshop
Corals don’t just have a tool-box, they have a Home Depot Warehouse. h/t to GWPF
The global increase in the atmosphere’s CO2 content has been hypothesized to possess the potential to harm coral reefs directly. By inducing changes in ocean water chemistry that can lead to reductions in the calcium carbonate saturation state of seawater (Ω), it has been predicted that elevated levels of atmospheric CO2 may reduce rates of coral calcification, possibly leading to slower-growing — and, therefore, weaker — coral skeletons, and in some cases even death.
by S. Xu et al., December 2017, in AGU1000Biogeosciences
Coral bleaching is becoming a serious issue for coral reefs under the stress of global warming. However, whether it has occurred in the past in times of thermal stress remains unclear. Moreover, an understanding of historic coral bleaching events would greatly improve our insight into the adaptive capabilities of corals under such stresses. It is known that Porites corals, a massive coral, have relatively high levels of symbiotic zooxanthellae and a strong thermal tolerance when compared with most other corals (and particularly branched corals). Thus, growth hiatuses and/or mortality surfaces of fossil Porites may be used to indicate past ecological or environmental stress events, such as severe bleaching. In this study, monthly geochemical and isotopic environmental proxies of four fossil Porites corals with well‐preserved growth hiatuses and mortality surfaces (aged 3,800–4,200 years before 2013 A.D.), collected from Wenchang fringing reef, Hainan Island, Northern South China Sea were analyzed. Specifically, the Sr/Ca, δ18O, and δ13C were measured with a monthly resolution for each sample.
By taking a closer look, scientists find resilience in face of heat stress.
Coral reef bleaching is stark evidence of the damage being inflicted by global climate change on marine ecosystems, but a research team has found some cause for hope. While many corals are dying, others are showing resilience to increased sea surface temperatures, pointing to possible clues to the survival and recovery of these vitally important aquatic habitats (…)
Coral reefs are facing no shortage of threats including ocean acidification, overfishing, plastic pollution, and rising temperatures. Sea surface temperatures have been climbing on average for over a century, and ocean heat waves—which can trigger coral bleaching events—are becoming more common and severe. Scientists have long worried that as coral-killing spikes in temperature become more frequent, corals won’t have enough time to recover between bleaching events and will ultimately go extinct. But a new paper, published today in PLoS Genetics, suggests that corals might be able to adapt to another century of warming.
Recent findings suggest that episodes of very rapid sea-level rise of about 20m in less than 500 years occurred in the last deglaciation, caused by periods of catastrophic ice-sheet collapse as the Earth warmed after the last ice age about 20,000 years ago.
Lead author, PhD candidate at the University of Sydney, Kelsey Sanborn, has shown this sea-level rise event was associated with “drowning” or death of coral reefs in Hawaii.
