Wednesday , November 25 2020

Look for serious educational events in the reef of the Pacific Coral Reef last century



90% of the coral was bleached in November 2015, but WHOI was alive when he traveled to Jarvis during the 2015-16 El Nino peak. Credit: Thomas M. D. Carlo Woods Vertebrate oceanographic organization

Climate change leads to an increase in ocean temperatures, and coral reef worldwide have experienced massive enlightenment and mortality. For many people, this is the first time that it comes to a very hot heat. However, heat waves caused by El Niño for some reefs in the Pacific Ocean are lifestyle. It is unclear how these reefs deal with extreme heat recurring episodes. A recent study of the Woods Hole Oceanographic Institution (WHOI) revealed the story of the elephant at the epicenter of El Nino and found that some coral reefers after the emergency. The study was published on November 8, 2018 Communication biology.


"This intensifying global warming is comparable to the atomic bomb when it comes to coral reefs – they kill millions of coral in ocean areas in a very short time," says WHOI scientist Ann Cohen, chief investigative worker. "We've seen this game all over the world for the last 30-40 years, and education activities are often more difficult."

If the water temperature rises slightly, symbiotic algae, living in the living coral cages, create toxic substances and remove them from the corals. Algae usually provide corals with food and energy as well as give them bright colors. Without it, corals seem to be "bleached" white, then open and die.

During the study, Cohen's group traveled to the island of Jarvis to explore the extreme climate of coral reefs traveling on a small, non-proprietary coral reef island south 1,400 miles south of Hawaii. Since Jarvis is a part of a protected and remote sea-protected zone, it has incredibly rich coral reefs, but in the midst of the Pacific, as well as the periodic El Nino events, are exposed to hot waves rather than coral reefs.

"Correctly placed in the equator on the Pacific Ocean shows it at the epicenter of the El Niño dynamics." says NOAA researcher Hannah Barkley, a master student who later defended his doctoral dissertation at Cohen's Laboratory, and was the author of the publication. "This can be a great fluctuation and excessive heat."

Since Jarvista has not had an observer note on the rifle until 2015, Cohen and Barkley have turned the massive old corals to more than 100 years in the rift. They made basic samples from corals and made skeletal biopsies recording the history of the reef. After implementing the nuclei through the CT scanner, they found the first evidence of some brightening events stored in the reef physical structure. The longest nuclei detected bleaching until 1912.

"When we blew the reef, we found that older corals contained a layer of calcium carbonate made up of" stress-groups "or a coral structure. historic heat waves, "says Cohen. Remembrance of Jarvis educational activities has been blocked by these pearls – they can say what happens, regardless of what we have not seen. «

Jarvis, for an average of four or seven years, experienced decades or even centuries of heat. The team notices that each heat wave has a breeze, but it always goes away quickly.

Based on the team's samples, the main causes of the reef's restoration are near-stream. The topography of the oceanic layer is combined with the strength of the terrestrial trading networks and comes from the cold, nutrient-rich water. This rebellion is intended for fish and other types of water around the rifle, which, in turn, eats the grass algae competing with coral. In this process, they were replaced by new, younger coral polyps.

Den Thornhill, director of the Department of Oceanographic Sciences of the National Science Foundation, funded by the research: "These reefs have been whitewashed and rebuilt several times. "However, the 2015-2016 educational program is particularly harsh, so the islands give us a fresh insight into how well the toughest corals in the world are facing severe educational stress."

Barzheli says, "Coral reefs such as Jarvis are needed to understand how far the other reef ecosystems grow after a wider bleacher."

But Super El Nino Jarvii 2015 was heated more than ever before, and the next record breakthrough was worse. About 95 percent of the island's coral has died.

"It's a big problem for us – the reef can be back to this day," says Barkley. "Even more rarer than Jarvis, the ever-diminished number of reefs, goes beyond what can not be rebuilt, and what's going to happen in the next few years will help us to understand what is going on."

However, it is optimistic. "Jarvis is just one example: rapid education and mortality around the world, the effects of climate change on the coral, as well as the fact that the historical data from our main samples are beyond our expectations," says Jarvis. There are narrow windows to eliminate, and some reefs may be exposed to major stress situations. «

"There are signs of restoration," says Cohen. "We are waiting, watching and learning right now."


Further research:
Study of severe enlightenment events in the reef of the Pacific Coral of last century

Given:
Forest oceanographic organization


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