Corals Good News
It is undoubtedly good news that corals had the ability to recover once before, suggesting that vulnerable ecosystems do have the resiliency to recover.
Corals Good News
A new study has found that Panamanian coastal coral reefs collapsed around 2,500 years, when oceanic temperatures were undergoing intense shifts through global warming, but on a more hopeful note, over the past two millennia, conditions returned to a more normal state, allowing the corals to not only return but also thrive.
The trouble is though, that current global weather in making especially strong and frequent El Niño and La Niña conditions much more prevalent, these being those that, in ancient times, caused the long-term decimation of Pacific corals, and could well do so again in the future, if global warming is not properly addressed.
It is undoubtedly good news that corals had the ability to recover once before, suggesting that vulnerable ecosystems do have the resiliency to recover, but many reefs are already damaged. Melbourne based coral reef ecologist/paleo-biologist Richard Aronson at the Florida Institute of Technology, commented that reefs can only recover if we do things to mitigate and reverse climate change.
In El Niño years, what happens is that warmer-than-usual waters flow into the eastern Pacific, upwelling stopping and waters becoming still, which causes corals to shed their symbiotic algae, turning white and dying - this process known as bleaching - which caused 16% of world corals to die off in a strong El Niño year in 1998.
Researchers pondered whether such extremes had happened before, and inserted a 17-ft long pipe into 14 dead reef sections off the Panama coast, obtaining in the process a representation of 6,000 years of reef history. The initial 30% of that time frame, the coral skeletons appeared healthy and well shaped, but the following 2,500 years worth showed chewed-up, poorly formed corals, suggestive of reefs undergoing sea bed stagnation.
The next 40% of the history - to 1,500 years ago, showed a period of devastated collapse of corals throughout the eastern tropical Pacific ocean, coinciding with a volatile time, climatically, for the El Niño and La Niña systems, both happening with both increased frequency and intensity, until calmer conditions re-occurred, causing corals to grow once more.
Latest climate change scenarios forecast many more extreme weather events this century, which could lead, all too quickly, to another collapse of coral stocks. However, the surprising resiliency of corals offers some hope, and whilst humanity may not be able to correct the damage already done to planetary atmosphere and climate, steps taken now to combat global warming climate might just make all the difference in saving at least some of the coral reefs around the world, which are such vital habitats for other creatures.