Relentless ocean heat takes toll on reefs worldwide
There’s been little let-up in the global wave of coral bleaching that’s been ongoing in various parts of the world since 2014, according to an update from NOAA’s Coral Reef Watch program. To date, the bleaching is the most widespread and damaging on record, including mass bleaching in areas where it’s never been seen before — the northern Great Barrier Reed, Kiribati and Jarvis Island.
And more of the same is expected in in the next few months as the Northern Hemisphere moves toward summer. Based on forecasts for the next two to three months, bleaching is likely in the eastern Pacific. Widespread coral bleaching with significant mortality continues in the Samoas (where bleaching of both shallow and deeper corals has now been confirmed) but is expected to dissipate shortly.
After extensive damage to the Great Barrier Reef, ocean temperatures finally cooled of in April, giving a respite to the corals that survived. Similarly, the corals around Florida also got some relief in the past few months. Get the full update at the NOAA coral reef watch page.
Scientists are currently mapping the biological damage caused by global warming
At the end of eastern Australia’s long, hot summer, ocean scientists are once again seeing devastating coral die-backs in the northern reaches of the Great Barrier Reef. Over the next few weeks, they’ll venture underwater to study how the coral communities responded to a second straight year of overheated water.
When temperatures pass a threshold, the coral expels its symbiotic algal partner, leaving underwater wastelands of white-washed reefs. The scientists will also use survey flights above the reef, and even satellite imaging as they mobilize to document one of global warming’s most devastating impacts. There has been a prolonged global mass bleaching under way for the past year, and climate researchers say nearly all the world’s corals will be at risk by mid-century under projected global temperature increases. Continue reading “Mass coral bleaching likely along northern Great Barrier Reef”→
After spending several months abroad in the autumn of 2015 I returned to the U.S. just in time for Christmas and New Years, as well as the lead-up to the Super Bowl. At the same time, the presidential campaign was starting to wind up, with Trump already spreading his poisoned rhetoric and the Democrats hopelessly divided and apparently unable to offer any meaningful positive message to counter the GOP hatefest.
But what I really noticed is that most Americans weren’t actually paying much attention to the unfolding election. The GOP primary was just another sideshow in the circus of consumerism and entertainment that has become of the mainstay of American civic life. To me, it felt like what a decaying Rome must have been experiencing as the empire waned, the masses entertained by excessive spectacles in the Coliseum, while the ruling class made its last-ditch effort to exploit society for short-term gain. It all crystalized for me in late January, when I saw three stories juxtaposed in the Denver Post: one on the Flint water crisis, a second on Trump’s ascendancy and a third on the armed takeover of a wildlife preserve by the Bundy malcontents. Taken together, the three articles represent the decline of American civilization. I wrote about it here.
In the West, the fracturing of the consensus on American values has often played out in the realm of public lands management, and nowhere is this more apparent than in discussions of endangered species. I saw this trend reinforced in mid-January at a Denver meeting on wolves, where it became clear that, for all the efforts that have been made, the reactionary opposition to predator restoration still prevails in the establishment. More in this in my wolf restoration post on Medium.
A new survey of the Great Barrier Reef shows that an ocean heat wave that peaked last March killed up to 95 percent of corals in some parts of the northern reef. And in the aftermath of the worst coral-bleaching event on record, predatory snails are now taking on toll on the remaining corals.
According to the ARC Centre of Excellence for Coral Reef Studies, researchers recently returned to 83 reefs they surveyed at the height of the bleaching event.
Study identifies bleaching and mortality thresholds for imperiled coral reefs
The steady rise in ocean temperatures projected for the next few decades will put more and more corals at risk of bleaching, as the warm water simply overwhelms their thermal tolerance mechanisms.
Recent research along the Great Barrier Reef shows that corals have been able to survive past bleaching events because they were acclimated to warmer temperatures by being exposed to a pattern of gradually warming waters in the lead up to each episode. But global warming is likely to change that, the scientists said.
Before long, temperature increases of as little as 0.5 degrees Celsius may push many corals over the edge as the warm water causes them to expel the algae-like dinoflagellates that help keep them alive and give them their color.
Lead author Dr. Tracy Ainsworth from Coral CoE said bleaching is like a marathon for corals.
Australian scientists have closely tracked the status of reefs along their coastline for the past few months as it became evident that this year’s strong El Niño would raise ocean temperatures above the limit of what most corals species can survive, and the latest survey results confirm their worst fears. In a press release, the researchers said the impacts are still unfolding along the 2,300-long reef, with the worst damage to the central and northern sections. Continue reading “Global warming kills a third of Great Barrier Reef’s corals”→