Coral bouncing back in West Hawaii

  • A Hawaiian honu swims over bleached cauliflower coral at Honokohau in 2015. Cauliflower coral was severely bleached along the West Hawaii coast that year. (Image by Lindsey Kramer)
  • A partially bleached cauliflower coral is pictured at Kua Bay in 2017. (Chelsea Jensen/West Hawaii Today)

KAILUA-KONA — It’s been four years since the worst bleaching event in state history and according to scientists from The Nature Conservancy, coral reefs in West Hawaii are stabilizing and poised to recover.

Higher than usual ocean water temperatures in 2015 caused the first statewide coral bleaching event. TNC surveys revealed that an average of 60 percent of corals in West Hawaii bleached, with some reefs experiencing up to 90 percent mortality. Corals bleach under stress, and severe or prolonged stress can lead to death.


For the last three years, TNC scientists have studied West Hawaii’s coral reefs to identify the most resilient.

“Bleaching events like what occurred in 2015 can overstress a coral reef to the point where it may never recover,” said Eric Conklin, director of marine science for TNC’s Hawaii program. “We surveyed over 14,000 coral colonies at 20 sites along the West Hawaii coast from Kawaihae to Keauhou and were thrilled to see that many of the area’s reefs have stabilized, which is the first step toward recovery.”

Surveys showed that many of the most resilient reefs are in remote areas with limited shoreline access and exposure to human impacts. These reefs had lots of corals and little or no coral disease, and there was evidence that new corals were beginning to grow.

The least resilient sites all had multiple “stressors,” including fishing pressure, land-based pollutants and runoff.

“Interestingly, the number of stressors affecting an area, not the severity of a single one, was the most important factor,” said Kim Hum, the Conservancy’s marine program director. “Reefs that are fighting the impacts of several stressors are more susceptible to temperature stress, making them more likely to bleach and less able to recover if they do.”

Surveys identified 25 coral species in West Hawaii. Lobe coral, also known as Porites lobata, one of the area’s most dominant species, proved to be the most resilient with only 50 percent bleaching in 2015. Cauliflower corals, also known as Pocillopora meandrina, were hardest hit with 98 percent bleaching. However, recent surveys show that cauliflower corals are beginning to recover.

“With more frequent and severe bleaching anticipated in the years ahead, there is a lot we need to do in West Hawaii,” Hum said. “We can make sure remote areas with few stressors stay that way, and we can reduce pressures from over-fishing, land-based pollutants and runoff in more populated areas.”


Currently, only 6 percent of state waters, which extend out to 3 nautical miles, and 12 percent of nearshore waters to a depth of about 160 feet have some form of management.

The state has committed to effectively manage 30 percent of the nearshore marine environment by 2030. The results of these surveys will help determine where and how to invest to ensure that Hawaii’s most resilient reefs are protected.

  1. diverdave January 23, 2019 4:07 am

    So then, the article admits that there has NOT been continuous ocean temperature increase since 2015.

    1. KonaDude January 23, 2019 6:57 am

      Negative climate change ( . Y .)

    2. Californian January 23, 2019 11:59 am

      According to the National Oceanic and Atmospheric Association (NOAA) ocean surface temperatures rise and fall over any short term time period, but the overall trend of the average ocean surface temperature has been steadily increasing over the last century and the trend is continuing through the present day. Even if your statistics are not just made up like most other times for you right-wing nuts, a decrease over a short time period of three years is a common occurrence and does not negate the fact that the temperatures on the ocean’s surface are steadily increasing.

      1. diverdave January 23, 2019 6:58 pm

        Of course you would say that.

        1. Californian January 24, 2019 5:14 pm

          Apologies all around. I am shamefacedly chastised. I will curb my enthusiasm.

    3. Brdy P. January 24, 2019 3:15 pm

      Just gotta push those buttons, don’t you DD?

      1. diverdave January 25, 2019 3:28 am

        If simply stating a fact means I “pushed those buttons” then perhaps those “buttons” need to be pushed.

        1. Brdy P. January 25, 2019 5:07 am

          I agree with you, DD. The cycle of annual ocean temperature swings and how it varies with events like El Nino is a complicated process. It cannot be described in terms like steady warming. The article missed the opportunity to explain the nuances of how local short term high and low temperature events fit into the larger long term trend of the oceans’ increasing heat content on a global scale.

  2. LOL in Kona January 23, 2019 8:03 am

    Send $$$ they need to “study” this more in Hawaii on the beach

    …after all, they are “experts”
    ……(‘ex’ – unknown as ‘explore’ – look at unknown,
    …….and ‘pert (spirt)’ – drop of water under pressure
    ……ex-pert – unknown drip under pressure who needs your $$$$)
    So send money, it is the only skill they have.

  3. J_Maritime January 23, 2019 8:40 am

    The article was a factual report on the results of a study of the ‘bleaching’ (dying) of our coral reefs that protect our island. Among other things, the report identified ‘areas of stressors’, that after being identified, may help in recovery or prevention of future bleaching events. All good information.

    Having worked, for years, with scientists who do studies similar to this, I can say that just about all of them take extra effort to keep their report factual.

  4. beyond kona January 23, 2019 11:38 am

    Cauliflower coral, a bushy species in the Hawaiian Islands have been devastated by ocean warming triggered by human-caused climate change, and today’s it’s a marine graveyard.

    Shallow-water corals — which are typically green, pink or cream-colored — have declined significantly, including a 36 percent drop in coverage across Hawaii from 1999 to 2012 – and this decline was prior the major 2015-16 bleaching event that hammered Hawai’i Island’’s West Coast.

    For the past five years I’ve continuous monitored the West Hawaii reef system, from North Kona through South Kohala, and the reef is not recovering – stabilization is not recovery. I would agree that are some scattered and highly limited signs of coral recovery, but increased stress and coral system die off is also continuing simultaneously and will likely overwhelm (based on our current path) any minor signs for hope for recovery.

    Protecting corals ultimately requires reducing global temperature increases by drastically cutting fossil fuel emissions. Yes, cauliflower and other corals are also threatened locally by land-based pollution, sedimentation, and physical disturbance caused by human activities, but ocean warming along with the rising acidification of ocean water are now the primary drivers for bleaching.

    Hawai’i and the Pacific are now pass the global warming tipping point and for TNC to cherry pick a highly limited observable finding, and declare victory, is a disservice to the reality now occurring in our local near shore marine ecosystems.

    1. Dan McNally January 23, 2019 3:29 pm

      Did we read the same article? Nowhere did TNC “declare victory.” Also, nowhere did the article say that stabilization is recovery. The article said: ““We surveyed over 14,000 coral colonies at 20 sites along the West Hawaii coast from Kawaihae to Keauhou and were thrilled to see that many of the area’s reefs have stabilized, which is the first step toward recovery.” If one were to seek a meaning in the article, it would be that the die off has slowed, not that all is well.

      1. beyond kona January 23, 2019 4:20 pm

        “…coral reefs in West Hawaii are stabilizing and poised to recover.”

        1. Dan McNally January 24, 2019 5:22 am

          Exactly – that does not mean stabilization equals recovery. Recovery can’t start until decline stops. Stabilization means “make or become unlikely to change, fail, or decline.” and recovery can’t start until an issue is stabilized. “Poised to recover” is not the same as “recovering.” I suspect you are reading into that article, things it just does not say.

  5. ingsoc January 28, 2019 8:00 am

    That’s impossible !

    Apparently they haven’t heard that “Climate Change” is destroying the entire solar system…..

    Silly experts. They need to talk to Al Gore and Alexandria Occasional-Cortex, they will set them straight….

  6. ingsoc January 29, 2019 8:05 am

    Al Gore is a con-man, not a scientist.

    Just for the record I’m not a right-winger,…. I’ve voted for
    Dukakis, Clinton twice, Gore, Kerry and Obama once (I no longer play the
    lesser of two evils roulette game)…., but I’m not an idiot either.

    So-called “Climate Change” is billionaire-fear-porn-fraud and endorsed by communists and the gang of 3rd world dictators known as the UN……

    Watch “The Great Global Warming Swindle” … a good place to START doing real research on the subject.

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