Friday, November 9, 2012

What's Troubling Coral Reefs?



This is a small portion of a coral with a white growth anomaly that is like a tumor. Diseases like this can spread over coral tissue, either making it more vulnerable to other threats or increasing coral mortality.

Corals thrive under very specific conditions. For this reason climate change and ocean acidification threaten coral fitness and health. Coastal development also introduces stresses to the coral reef environment. These include pollution, destructive fishing and boating practices, and over fishing. The confluence of these many factors makes corals less fit and more susceptible to disease. One of the research goals of this expedition is to better characterize disease in healthy populations in order to better understand disease in stressed populations. 

Disease is present in all populations of animals, but as you might expect, when a population is already stressed an opportunity is created for disease to gain a stronger foothold and destroy that population. One example is that of the Caribbean.

Before the 1970’s the Caribbean coral reef was flourishing. However, overfishing removed almost all the herbivorous (vegetarian) fish.  The lack of herbivorous fish to crop back algae (like seaweed) creates an opportunity for algae to outcompete the coral for space. At the time, there were still lots of urchins around to eat the algae. Unfortunately, as coastal development continued and additional stresses accumulated, a disease outbreak devastated the urchin population. This tipped the balance in favor of algae, and the algae progressively smothered the corals.  If you visit the Caribbean today, most of what you see is algae and dead coral. There are still some live corals, but they are very different from the types of coral than once lived there.

Although the general story of the Caribbean is a sad one, we do find hope for Caribbean corals in the reserves. These small reserves demonstrate that, with proper management and conservation, the coral reefs can recover to some extent.

The next goal is to create measures to also protect Hawaiian coral reefs, which are presently following the destructive path that we saw in the Caribbean.  These measures include managing fishing and pollution, and monitoring and treating coral disease. Fortunately, scientists, like those on this ship, are discovering more about what diseases are present in healthy and stressed populations, and are developing ways to treat them. Their research will go toward preserving coral reefs in US waters and worldwide.

6 comments:

  1. Interesting that it was only in 1970 that the coral reefs were flourishing. It was such a short time ago yet so much pollution has affected the growth. I loved what you had to write. It is very interesting and the photo is just beautiful. Love, MOM

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  2. Coral cancer! Wow, what an interesting photo that brings the point home about coral disease. It's hard to picture inanimate objects having disease but this does it well. Glad to be able to read about your experiences over there!

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  3. I think the picture of the tumor is really intersting. I was surprised that it wasn't very ugly. But, you could definitely tell it was tumor or an unusual appendage. Is it hard like coral? Do you guys break them off and sample them too? Would it be of value to you to know how long the tumor has been growing and at what rate? Love you tons. Inquisitive New Mexican

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  4. Tonga 6.1 Earthquake, 17 Nov 2012 05:12:56 UTC.

    Don't know where exactly you are but doubt you felt it.

    http://earthquake.usgs.gov/earthquakes/eventpage/usc000du43#summary

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  5. Nope, we didn't feel it up here in Micronesia. Finished the cruise with a week in Pohnpei, and just returned to the desk. Need to enter one or two more entries to wrap up the story. How was Bali?

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  6. Never went ... Obama's visit took over here, and now there's another Thai crisis brewing, so busy here.

    Thought you might be interested in this though, lol. South Pacific Sandy Island 'proven not to exist' - BBC.

    http://www.bbc.co.uk/news/world-asia-20442487

    Sort of 'reverse' exploration. lol

    Cheers.

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