Scientists expect Hawaii's worst coral bleaching ever

September 12, 2015 byAudrey Mcavoy
Scientists expect Hawaii's worst coral bleaching ever
This Sept. 10, 2015, photo provided by the Hawaii Department of Land and Natural Resources shows partially bleached coral in Kaneohe, Hawaii. Warmer-than-normal ocean temperatures around Hawaii this year will likely lead to the worst coral bleaching the islands have ever seen, scientists said Friday, Sept. 11. (Dan Dennison/Hawaii Department of Land and Natural Resources via AP)

Warmer-than-normal ocean temperatures around Hawaii this year will likely lead to the worst coral bleaching the islands have ever seen, scientists said Friday.

Many corals are only just recovering from last year's , which occurs when warm waters prompt to expel the algae they rely on for food, said Ruth Gates, the director of the Hawaii Institute of Marine Biology. The phenomenon is called bleaching because coral lose their color when they push out algae.

The island chain experienced a mass bleaching event in 1996, and another one last year. This year, ocean temperatures around Hawaii are about 3 to 6 degrees Fahrenheit warmer than normal, said Chris Brenchley, meteorologist for the National Weather Service in Honolulu.

Bleaching makes coral more susceptible to disease and increases the risk they will die. This is a troubling for fish and other species that spawn and live in . It's also a concern for Hawaii's tourism-dependent economy because many travelers come to the islands to enjoy marine life.

Gates compared dead coral reef to a city laid to rubble.

"You go from a vibrant, three-dimensional structure teeming with life, teeming with color, to a flat pavement that's covered with brown or green algae," said Gates. "That is a really doom-and-gloom outcome but that is the reality that we face with extremely severe bleaching events."

Gates said 30 to 40 percent of the world's reefs have died from bleaching events over the years. Hawaii's reefs generally have been spared such large scale die-offs until now. Most corals bleached last year bounced back, for example. But Gates said it will be harder for these corals to tolerate the warmer temperatures two years in a row.

"You can't stress an individual, an organism, once and then hit it again very, very quickly and hope they will recover as quickly," she said.

Scientists have reports of bleaching in Kaneohe Bay and Waimanalo on Oahu and Olowalu on Maui. For the Big Island, reports of bleaching have come in from Kawaihae to South Kona on the leeward side and Kapoho in the southeast.

Scientists on an expedition to the remote, mostly uninhabited islands in the far northeastern end of the island chain reported some coral died after last year's bleaching event. Courtney Couch, a researcher at the Hawaii Institute of Marine Biology, said a mile and a half of reef on the eastern side of Lisianski Island was essentially dead. Coral further out from the atoll handled the warm temperatures better, she said.

Brian Neilson, an aquatic biologist with the state Department of Land and Natural Resources, said people could help by not adding to the coral's problems.

That means avoiding fertilizing lawns and washing cars with soap so contaminants don't flow into the ocean. People should avoid walking on coral and boaters should make sure they don't drop anchor on coral. Fishermen should fish responsibly, he said.

Scientists have also asked people to help them keep track of bleached coral by reporting sightings to the state's "Eyes on the Reef" website at www.eorhawaii.org .

Brenchley, from the National Weather Service, said it's not known why waters around Hawaii and other parts of the northeast Pacific are warmer than normal this year. This warm water—nicknamed "The Blob"—is coinciding with El Nino, which is a general warming of parts of the Pacific that changes weather worldwide. But Brenchley said it isn't the result of El Nino.

Hawaii is home to 85 percent of the coral under U.S. jurisdiction, including 69 percent within the mostly uninhabited islands of the Papahanaumokuakea Marine National Monument. Another 15 percent of U.S. coral lies among the Main Hawaiian Islands—from Niihau in the north to the Big Island in the south—where the state's 1.4 million people live.

Explore further: NOAA: Warm oceans cause concern of coral bleaching (Update)

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8 comments

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unrealone1
1.8 / 5 (5) Sep 12, 2015
There has been no global warming for 18 years how can the Hawaii's ocean be getting warmer? Fukushima?
denglish
2 / 5 (4) Sep 12, 2015
Here's a trending of Hawaiian water temperatures:
https://bobtisdal...ssta.png
One wonders how the coral survived before.

This year, ocean temperatures around Hawaii are about 3 to 6 degrees Fahrenheit warmer than normal

El Nino?
zz5555
3.7 / 5 (6) Sep 12, 2015
There has been no global warming for 18 years how can the Hawaii's ocean be getting warmer? Fukushima?

What makes you think there's been no warming for the last 18 years? Surface temperature records show statistically significant warming for the last 18 years. If you're using satellite records to make this claim, remember that the error in the satellite records over that period is so large that you can't say with any confidence whether the temperature has increased or decreased or stayed the same. Besides, satellites can't measure the surface temperature and have a number of other problems inherent in their models, so depending on them for surface temperatures is rather silly.
abecedarian
1.7 / 5 (6) Sep 12, 2015
"Normal" compared to what? Oceans have been both warmer and cooler than they are now, so anything within those bounds would be "normal".

Life managed to get by.
abecedarian
1.7 / 5 (6) Sep 12, 2015
"Normal" compared to what? Oceans have been both warmer and cooler than they are now, so anything within those bounds would be "normal".

Life managed to get by.

Always nice to be down-voted for telling the truth.

Too bad none who down-voted had any rebuttal or explanation regarding why they did so, so as to give me the chance to have cordial discussions. Must be people with an agenda or a pleeb.
zz5555
4.3 / 5 (6) Sep 13, 2015
I think you were down-voted because your comment was unbelievably silly. Oceans have been warmer and cooler than they are now, but the conditions under which that was the case were generally very different than they are now. You could only claim conditions now are "normal" if you accept that it is normal for the earth to rapidly warm. But that doesn't appear to be a valid claim since only rarely, if ever, has the earth warmed this rapidly. Really, this rapid warming is anything but normal.

As for "life managed to get by", the last time something similar to this happened there was a rather large extinction event. I'm sure life will get by, but it's not going to be comfortable for those who survive. And it will be costly, both in lives and financially (assuming civilizations survive). And much of it is preventable.

So your statement was really quite silly and not really very related to "the truth".
zz5555
4.2 / 5 (5) Sep 13, 2015
As for "cordial discussions", that's something I haven't experienced with the anti-science group. You can start out refuting their silly statements (like "it hasn't warmed in 18 years") and they'll claim all sorts of nonsense. Generally, it seems that these anti-science people don't have the intelligence to understand the silliness in the claims they make and lack the desire to learn enough to gain that understanding. Or if they do have enough of a background to understand, they are so rigid in their political beliefs that they don't care about "the truth" - all "truth" is dictated by their politics. Frankly, I'm not sure it's worth my time having discussions with people that lack the ability to hold their end up in the discussion.
Captain Stumpy
4.3 / 5 (6) Sep 13, 2015
Too bad none who down-voted had any rebuttal or explanation
@abecedarian
1- see zz5555 above
2- you offered your opinion: there is nothing scientific about it
3- you offer no validation of your claims
4- you equate life (in general) from the past with current specific conditions but don't correlate anything, show where similar fluctuations didn't cause coral damage, etc...

basically, you made a personal conjecture that was, in zz's wording (which seems accurate) "quite silly" and offered no evidence to support your vague general claims

that is typically used by others (with an agenda) to troll and bait... so it was likely assumed to be similar considering the above and your reaction to the downvote

if you had actually made a point with links/evidence to reputable studies, you might have actually been able to engage in cordial discourse

if you would like to continue, feel free to reword, offer your evidence, tie it with the topic and wait

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