Category: coral reefs

Australian scientists say parts of Great Barrier Reef survived bleaching

Northern section hammered by warm ocean temperatures

This NASA photo shows southern portion of the reef adjacent to the central Queensland coast
This NASA photo shows a southern portion of the Great Barrier Reef adjacent to the central Queensland coast.

Staff Report

Australian researchers this week released results of their latest Great Barrier Reef surveys, concluding that huge swaths of coral died in the past year under the onslaught of an ocean heatwave that led to widespread coral bleaching.

In the hardest-hit area along a 700-kilometer section of the northern reef, an of 67 percent of shallow-water corals died in the last six to nine months. Farther south, over the vast central and southern regions of the Great Barrier Reef, the scientists were relieved to find a much lower death toll. Continue reading “Australian scientists say parts of Great Barrier Reef survived bleaching”

New surveys confirm Great Barrier Reef damage

Heat-driven coral bleaching continues to take a toll

Staff Report

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.

“Millions of corals in the north of the Great Barrier Reef died quickly from heat stress in March and since then, many more have died more slowly,” said Dr. Greg Torda whose team recently returned from re-surveying reefs near Lizard Island. Continue reading “New surveys confirm Great Barrier Reef damage”

Bleaching risk on the rise for Great Barrier Reef corals

Global warming is likely to overwhelm corals'
Global warming is likely to overwhelm corals’ built-in thermal tolerance mechanisms within the next few decades, leading to more bleaching and mortality. Photo courtesy Dr. Peter Mumby.

Study identifies bleaching and mortality thresholds for imperiled coral reefs

Staff Report

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.

“When corals are exposed to a pre-stress period in the weeks before bleaching, as temperatures start to climb, this acts like a practice run and prepares the coral. Corals that are exposed to this pattern are then less stressed and more tolerant when bleaching does occur,” Ainsworth said. Continue reading “Bleaching risk on the rise for Great Barrier Reef corals”

Florida harbor dredging threatens corals

Mapping coral diseases is helping researchers determine the cause. Photo courtesy NOAA.
Mapping coral diseases is helping researchers determine the cause. Photo courtesy NOAA.

Activists plan lawsuit to win more environmental protection

Staff Report

Even with coral reefs around the world under the global warming gun, the U.S. Army Corps of Engineers is seeking approval for a controversial Florida dredging project that could smother parts of the only coastal barrier reef in the continental United States.

But a coalition of environmental and community groups have banded together to try and the the Corps to provide mandatory, common-sense protections for reefs near the Port Everglades dredging project near Fort Lauderdale. The project’s goal is to increase coastal access for larger ships. Continue reading “Florida harbor dredging threatens corals”

Twitter analysis tells volumes about climate politics

Many senators stuck in a social media echo chamber

Staff Report

University researchers took a deep dive into the world of social media to reach some interesting conclusions about climate change and political beliefs. After analyzing the Twitter streams of U.S. senators, the scientists said Democrats were three times more likely than Republicans to follow research-oriented science organizations, including those covering global warming.

The paper, published in the journal Climate Change Responses, reinforces that fact that climate science has inexplicably become a partisan issue, but with a ray of hope. On the GOP side of the aisle, 15 senators displayed a draw to science and thus a way to bring scientific information to those not receiving it on their own.

“Increasingly, people are using Facebook and Twitter as a means of getting news, which determines what information they are exposed to,” said Brian Helmuth, a marine biologist and an ecologist at Northeastern University’s School of Public Policy and Urban Affairs. Continue reading “Twitter analysis tells volumes about climate politics”

Global warming kills a third of Great Barrier Reef’s corals

Similar mortality expected in other tropical oceans

Dead and dying staghorn co ral , central Great Barrier Reef in May 2016. Credit: Johanna  Leonhardt
Dead and dying staghorn coral, central Great Barrier Reef in May 2016. Photo by Johanna Leonhardt.
Great Barrier Reef mortality map
Map of mortality estimates on coral reefs along 1100km of the Great Barrier Reef. Map courtesy ARC Centre of Excellence for Coral Reef Studies at James Cook University.

Staff Report

For years, scientists have warned that global warming threatens to decimate the world’s coral reefs within our lifetimes and this week, the dire warnings played out in Australia, where new surveys showed that more than a third of the corals along the Great Barrier Reef died in the past few months after an extensive coral bleaching episode.

“We found, on average, that 35 percent of the corals are now dead or dying on 84 reefs that we surveyed along the northern and central sections of the Great Barrier Reef, between Townsville and Papua New Guinea,” said Professor Terry Hughes, director of the ARC Centre of Excellence for Coral Reef Studies at James Cook University.

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”

Australian scientists document massive coral bleaching along the Great Barrier Reef

Global warming impacts on reefs unfolding as projected

Great Barrier Reef coral bleaching 2016
Aerial surveys by Australian researchers shows that at least 40 percent of the Great Barrier Reef has been affected by bleaching. Photo courtesy ARC Centre of Excellence for Coral Reef Studies / Terry Hughes.

Staff Report

Global warming has been driving the worst and longest episode of coral reef bleaching on record, and the event is hitting the Great Barrier Reef especially hard. Australian scientists this week said their latest aerial surveys of more than 500 reefs show that the most pristine section of the Great Barrier Reef is currently experiencing the worst, mass bleaching event in its history, with the overwhelming majority of reefs being ranked in the most severe bleaching category.

Widespread coral reef bleaching started in 2014, even before El Niño kicked into high gear. As forecasts for this year’s El Niño became more certain, ocean scientists warned in advance that widespread bleaching, spurred by warm ocean temperatures, would occur. There’s plenty of research that enables scientists to project bleaching events, and last November, NOAA warned that reefs around the world would be affected this year. In February, NOAA announced that record and near-record ocean temperatures are prolonging the longest global coral die-off on record.

The latest data from the Australian researchers confirms all the projections and worst fears that global warming will likely decimate most coral reefs worldwide. That, in turn, could affect entire ocean ecosystems, since reefs are the nurseries of the seas.

“This has been the saddest research trip of my life,” said Prof. Terry Hughes, with Australia’s National Coral Bleaching Taskforce. “Almost without exception, every reef we flew across showed consistently high levels of bleaching, from the reef slope right up onto the top of the reef. We flew for 4,000 kilometers in the most pristine parts of the Great Barrier Reef and saw only four reefs that had no bleaching. The severity is much greater than in earlier bleaching events in 2002 or 1998,” Hughes said. Continue reading “Australian scientists document massive coral bleaching along the Great Barrier Reef”