bleaching tagged posts

A simple but powerful idea is to improve the health of corals using cocktails of beneficial bacteria. The strategy is being explored as part of global scientific efforts to help corals become stronger, more stress resistant and more likely to survive bleaching events associated with climate change.

Corals rely on bacterial and algal symbionts to provide nutrients, energy (through photosynthesis), toxin regulation and protection against pathogenic attacks. This complex and finely balanced relationship underpins the health of the holobiont and coral reefs as a whole.

Rather like the use of probiotics in plant science to improve growth and resilience, marine scientist Raquel Peixoto believes that, in times of stress, corals could benefit from a boost to their natural symbiotic partners...

With WA’s coastline enduring a marine heatwave event, marine scientists have raised concerns about coral bleaching events along the Coral Coast. Sea surface temperatures were up to 3C warmer than average in January, and are expected to reach their highest levels in a decade by April, according to data from the CSIRO.

Australian Institute of Marine Science’s coral ecologist Dr James Gilmour, pictured, believes the thermal stress of the heatwave may lead to coral bleaching events in Ningaloo, Shark Bay and the Abrolhos Islands.

“Low level bleaching has already been observed in parts of Exmouth Gulf,” he said.

“While the recent tropical low has reduced environmental temperatures, the risk of bleaching will continue in the coming weeks.”

The Bureau of Meteorology says ...

Australia’s Great Barrier Reef has lost more than half of its corals since 1995 due to warmer seas driven by climate change, a study has found. Scientists found all types of corals had suffered a decline across the world’s largest reef system. The steepest falls came after mass bleaching events in 2016 and 2017. More mass bleaching occurred this year. 

“There is no time to lose – we must sharply decrease greenhouse gas emissions ASAP,” the researchers said.

The study, published in the journal Proceedings of the Royal Society B, was conducted by marine scientists at the ARC Centre of Excellence for Coral Reef Studies in Queensland.

Scientists assessed the health and size of coral colonies across the reef from 1995 to 2017.

They found populations had dropped by more than 50% in...

Scientists in Australia say they have found a way to help coral reefs fight the devastating effects of bleaching by making them more heat-resistant. Rising sea temperatures make corals expel tiny algae which live inside them. This turns the corals white and effectively starves them.

In response, researchers have developed a lab-grown strain of microalgae which is more tolerant to heat.

When injected back into the coral, the algae can handle warmer water better.

The researchers believe their findings may help in the effort to restore coral reefs, which they say are “suffering mass mortalities from marine heatwaves”.

The team made the coral – which is a type of animal, a marine invertebrate – more tolerant to temperature-induced bleaching by bolstering the heat tolerance of its microalgal s...

More than half of the spectacular and remote coral reefs beyond the boundaries of the Great Barrier Reef suffered severe bleaching this summer, an underwater scientific expedition has found. Several reefs in the vast Coral Sea marine park known among divers for their arrays of corals, large fish and precipitous drop offs into the deep ocean suffered extreme bleaching. Scientists from James Cook University’s ARC Centre of Excellence for Coral Reef Studies recorded the bleaching on the reefs that are more than 200km offshore during dives in February and March.

Some reefs had 90% of their shallow water corals bleached – an extreme level likely to lead to deaths of many corals, said Prof Andrew Hoey, a co-ordinator of the expedition.

Hoey said: “It’s becoming too familiar to jump in to t...

Rising ocean temperatures could have pushed the world’s tropical coral reefs over a tipping point where they are hit by bleaching on a “near-annual” basis, according to the head of a US government agency program that monitors the globe’s coral reefs.

Dr Mark Eakin, coordinator of Coral Reef Watch at the National Oceanic and Atmospheric Administration, told Guardian Australia there was a risk that mass bleaching seen along the length of the Great Barrier Reef in 2020 could mark the start of another global-scale bleaching event.

Tropical coral reefs tend to be at a higher risk of bleaching during times when the Pacific Ocean is in a phase known as El Niño. The latest bleaching on the reef has hit during this cycle’s neutral phase.

“The real concern is with this much bleaching with...

Repeated coral bleaching events owing to global warming are having lasting effects on reef fish communities, including changes in biodiversity and permanent shifts in the range of fish species, according to a new long-term study published on 18 June in Global Change Biology (1). Future reef fish communities will have fewer species, dominated by herbivores and invertebrate feeding fish.

The international team of researchers led by Dr James Robinson of Lancaster University carried out six surveys of 21 Seychelles reef sites from 1994 to 2017. They tracked the recovery of reefs over the 16-year period before the next major bleaching event in 2016 and discovered permanent shifts in the range of fish species cohabiting the coral reef sites.

The authors then used statistical models...

The world’s southernmost coral reefs have fallen victim to climate change. According to reports, the Lord Howe Island Marine Park is experiencing severe coral bleaching.

In some areas, about 90 percent of reefs have been damaged. Scientists said that this is the worst coral bleaching that the UNESCO World Heritage Site has experienced in recent memory.

Warm Summer Water Causes Widespread Coral Bleaching

Researchers from Newcastle University, James Cook University, and the National Oceanic and Atmospheric Administration have surveyed the area for the past two weeks. They revealed that the bleaching occurred over the past summer, peaking in March, due to sustained heatwaves and warm ocean water temperature.

They also reported that the bleaching is at its most severe in shallow w...

At Mote Marine Lab’s Center for Coral Reef Research and Restoration in the Florida Keys, Joey Mandara is like a baby sitter. But instead of children he tends to thousands of baby corals, growing in large, shallow tanks called raceways. Mote has been doing this work for five years, raising corals from embryos into adult colonies, then planting them on Florida’s reefs. Now, the emergence of a new, debilitating coral disease makes his work more important than ever.

In one raceway, Mandara says fragments of brain coral have grown quickly in this controlled environment.

“The brain coral were eight fragments,” he says. “And over time, they’ve grown out and have now fused into each other, becoming one coral that will hopefully over time become sexually mature.”

Mote lab’s science director Erinn...

The researchers from UWA, the ARC Centre of Excellence and WA Marine Science Institution found Ningaloo Reef, which is still recovering from major bleaching in 2010-11, was not affected.

The 2016 global bleaching event was the third and longest on record and the Kimberley region was the hardest hit.

Between March and May 2016, the world’s oceans were 0...