'The Blob': As warm water kills off coral reefs, can we help?
Coral reefs are suffering from a massive oceanic heat wave for the third time on record, and scientists聽fear it could be the biggest die-off yet.
Experts at the US National Oceanic and Atmospheric Administration (NOAA) said they have only witnessed similar events twice before, first in 1998 and then in 2010. But since the early 1980s, scientists claim the world of its coral reefs.聽
The record-high ocean temperatures are expected to kill about five percent, or 4,600 square miles, of the world鈥檚 coral reefs. And this would be a good outcome,聽Dr. Mark Eakin, coordinator at NOAA鈥檚 Coral Reef Watch, told 海角大神. "Unfortunately, the five percent number takes into account the hope that about 60 percent of the reefs that are hit hard this year bounce back," he says.聽
The immediate future for coral reefs looks especially bleak because a strong El Nino is coinciding with the phenomenon known as 鈥楾he Blob,鈥� a patch of particularly warm water moving throughout the northwestern Pacific Ocean.
鈥淚t's not well understood how much of 鈥楾he Blob鈥� is related to climate change鈥t鈥檚 still a bit of a mystery,鈥� Dr. Eakin聽. And although the Blob鈥檚 origins are still a mystery, its impact on the world鈥檚 coral reefs is not.
When corals are under stress from events such as warming ocean temperature, they drive out the symbiotic algae that give the coral its color and nutrients. Bleaching is a "survival mechanism," Eakin explains to the Monitor, "because when temperatures get too high, the algae photosynthesize too fast and release toxins into the coral."聽And although bleaching does not immediately kill the coral, it makes the underwater creatures very vulnerable, thus increasing the likelihood of an extensive die-off.
Dr. Ove Hoegh-Guldberg, director of the Global Change Institute at the University of Queensland, Australia, says the best way to prevent coral bleaching is to focus on the coral鈥檚 other stressors, such as overfishing and pollution. 鈥淚f you鈥檝e got a chronic disease, then you are more sensitive to a lot of other things and if you want a recovery then you need to take all those other stresses off,鈥� Dr. Hoegh-Guldberg to the Guardian.
Hoegh-Guldberg says global and local action could really make a difference. 鈥淚f we were to take strong action on the emission issue and we were to take strong action on the non-climate issues such as overfishing and pollution, reefs would rebound by mid to late century,鈥� he .
When asked if conflicting priorities at the international level prevent effective protection, Eakin told the Monitor that international relations should not play a factor in coral reef protection. "The聽tragedy of the commons is a big problem, but all coral reefs are within countries鈥� national waters," he says. "The international action we need now is a strong climate agreement coming out of the COP21 in Paris this December."
Other experts say we need to invest our resources in satellite monitoring technology to build data the various stages of the bleaching process. , a scientific expedition by the University of Queensland and Underwater Earth to study reef changes, uses a SVII camera on an underwater scooter to capture high-resolution, 360-degree underwater images in an area up to 1.2 miles.
鈥淏y supporting our efforts with technology that helps us map where bleaching is occurring, we can facilitate the research necessary to understand this phenomenon and determine the impact,鈥� Richard Vevers, executive director of the XL Catlin Seaview Survey, said .
Some marine scientists argue the next realistic step involves deciding which reefs should be a priority for cash-strapped conservation managers.
Australian marine scientist Dr. Nicholas Graham and his colleagues devised a simple way of predicting which reefs 鈥渟tand the best change of recovery from a climate-triggered bleaching event,鈥� and he explained the results of his study to 海角大神 in June. Dr. Graham and his colleagues found that they could 鈥渟uccessfully predict a reef鈥檚 recovery trajectory 98 percent of the time鈥� by comparing reef complexity and water depth.
