Coral bleaching ‘new normal’ say scientists

| 05/01/2018 | 15 Comments
Cayman News Service

The devastating results of coral bleaching

(CNS): Scientists have found that the time-lapse between coral bleaching events has decreased rapidly over the last forty years, reducing the time reefs have to recover and making bleaching the “new normal” for the delicate marine ecosystems. In the latest bad news about the fate of the earth’s ocean-life, researchers found that the average time between the bleaching and mass mortality of corals has dropped from around 25 or more years to just six years, which scientists say is not long enough for coral to recover.

The results of the study, which was published in the latest edition of the journal Science, points to increasing global temperatures.

The lead author, Terry Hughes of the ARC Centre of Excellence for Coral Reef Studies based at James Cook University in Queensland, Australia, said, “Before the 1980’s, mass bleaching of corals was unheard of, even during strong El Niño conditions, but now repeated bouts of regional-scale bleaching and mass mortality of corals have become the new normal around the world as temperatures continue to rise.”

The study collected data from 100 reef sites around the world and the results showed that tropical sea temperatures are warmer today during cooler-than-average La Niña conditions than they were 40 years ago during El Niño periods.

The bleaching events are now having dire consequences on the complex coral reef ecosystems because six years is not long enough for the reefs to recover before more bleaching happens. The scientists explained that even the fastest growing coral communities take approximately 10 to 15 years to recover after a bleaching event.

“Reefs have entered a distinctive human-dominated era – the Anthropocene,” said Mark Eakin of the US National Oceanic and Atmospheric Administration, who worked on the same study. “The climate has warmed rapidly in the past 50 years, first making El Niños dangerous for corals, and now we’re seeing the emergence of bleaching in every hot summer.”

The researchers said the future conditions of reefs, and the ecosystem services they provide to people, will depend critically on the trajectory of global emissions.  The bleaching is not the only problem that scientists have found is becoming more intense. Other researchers are warning of a coming algae and sponge ‘Apocalypse’ that will choke coral reefs to death in the Caribbean.

Speaking to the National Geographic magazine recently about his work in this region, Joseph Pawlik, an ecologist and leading sponge expert at the University of North Carolina in Wilmington, said evidence is mounting that sponges and algae are pushing out the corals and are achieving reef domination. Warming temperatures and upsets in the delicate ecosystem balance from toxins and bacteria in the water due to increased cargo traffic has impacted the marine creatures, such as urchins to turtles, that would otherwise be the cleanup crews that keep sponges and algae at bay.

Pawlik says that in just a few years, algae has gone from a minor player to a dominant one on many reefs in the Caribbean, and sponges have moved into the space once occupied by coral. He explained that this partnership is an “unstoppable force”.  Algae bathed in sunlight can produce more sugar than they need and sponges crave sugar and then excrete plenty of the nitrogen and other nutrients that algae needs. Pawlik said in terms of biomass, sponges have become the dominant animal on Caribbean reefs.

“They’re not coral reefs anymore; they’re algae-sponge reefs,” he warned.

And while he and other scientists agree that sponges aren’t all bad, as they play a crucial role in filtering water and concentrating nutrients for all kinds of animals, they don’t build reef but pull it apart. Having a balance between coral and sponge is crucial to healthy reef systems; if the balance is tipped the ecosystem will crash, and Pawlik believes the loss of balance in the Caribbean could be devastating.

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Category: Marine Environment, Science & Nature

Comments (15)

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  1. Anonymous says:

    “250 million years ago oxygen levels on earth = 35 percent. In 1850, oxygen levels = 22 percent. Today’s levels now hover around 19 percent or less in most westernized cities. This assumes, of course, these cities are at sea level. O2 levels required for healthy humans = 19.5 percent. This proof is found on an oxygen dissociation curves of hemoglobin. This is not a good development for our mitochondria. But this is really bad news for modern day marine life.”

    Every single statement in this blog is backed by hard core science (listed).

  2. Anonymous says:

    Coral farms would create jobs, coral growth and gene modification research to withstand higher acidity would ensure Cayman prosperity in the future. But I doubt, squirrell, we have the focus in leadership who can’t see beyond their a$$oles, especially when they preach how proud they are of their hertitage even as they see it decimated under their management.

  3. Anonymous says:

    does anyone on here believe that if the oceans health declines and ultimately dies, so do we?

  4. West bay Premier says:

    Those bleached spots in the corals are caused by some idiot pouring bleach down into the coral to get lobsters out of the coral .

    • Anonymous says:

      WBP, have you ever considered ceasing to write complete drivel? If that was supposed to be humor you need a funny bone installed.

  5. Anonymous says:

    I swim in the sea a lot, and to my eye, whilst nowhere near as bad as last year(2016 summer), bleaching was still occurring here. It’s real folks. We need to deal with it.

  6. Anonymous says:

    Far from normal.

  7. Anonymous says:

    Coral schmoral, we don’t need no stinking coral. Build the damn dock!

  8. Al Catraz says:

    Scientists! What do they know. Not a lick of common sense among them.

    • Anonymous says:

      Are you trying to be sarcastic? That doesn’t translate well on comment boards. You should end with a ? emoji to help us understand if you’re a complete moron or not.


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