Wednesday, June 12, 2013

Restoring Our Reefscape

© Richard Chesher
Ecosystem services are services produced through nature that directly and indirectly benefit humanity and support the entire Earth, such as purifying water, cycling nutrients, pollinating plants, or sequestering carbon. The importance of coral reefs cannot be understated; in terms of ecosystem services they provide habitat for an estimated 25-40% of discovered marine organism biodiversity (many of which are captured by us), aid in the protection of beach erosion, and - most importantly to many - serve as an excellent source of recreation. It should be mentioned that coral ecosystem’s biodiversity is unequaled in its genetic diversity also, providing key components of potential lifesaving compounds, such as those that fight some of the “worst infectious bacterial strains”, according to the National Oceanic and Atmospheric Administration.

But the coral reefs are at a greater risk of loss now than they have ever been in recorded history. A large amount of this blame rests on the shoulders of humanity in what has been informally termed the “Anthropocene” epoch by geologists and environmentalists. Increased ocean temperatures, mainly from increased greenhouse gas emissions by humans, and overfishing are two detrimental human-caused factors.

Readings of the carbon dioxide levels from May 2nd-7th, 2013 from the
Scripps Institution of Oceanography at the Mauna Loa Observatory.
Greenhouse gas changes caused by humans includes the majorly increased levels of carbon dioxide, stemming mainly from burning fuels based on carbon, like natural gas, oil, coal and wood. The increased carbon dioxide in the atmosphere cannot all be taken up in the usual chain of events, including photosynthesis that converts CO2 into organic carbon. The excess carbon dioxide is absorbed by the ocean, interacting with the seawater to create carbonic acid, which in turn decreases pH and affects the resident organisms. On May 7th of this year, the carbon dioxide levels of the Mauna Loa Observatory reached 400 ppm – frightening, considering that the last time carbon dioxide levels were this high was nearly 2.5 million years ago and far higher than the pre-industrial 280 ppm.

In this symbiotic relationship, coral

provides carbon dioxide and water
for the algae's photosynthesis. The 
zooxanthallae releases oxygen, fats, 
and sugars - necessary for coral 

© NOAA Ocean Service Education
The increase in acidity and temperature of the ocean is detrimental to coral reefs. Why? Because of the reefs symbiotic relationship with the algae known as zooxanthallae. When at healthy oceanic levels, the algae provide the coral polyps with oxygen, fats and sugars, which the coral then utilize for cellular respiration. The algae also provide the coral with its trademark bright colors. Cellular respiration creates CO2 and water, which the algae use for photosynthesis. To simplify this relationship, take a look at the animation on the right:

When coral polyps come under the stress of decreased pH and increased temperature, they may expel the zooxanthallae from their cells. This leads to the coral bleaching, the tell-tale sign of the algal expulsion. When coral bleaching occurs, the coral is weakened and therefore more susceptible to diseases and bacterial or viral infections [1]. Australian researchers have found an incredible way to measure the stress of corals. Recently, these researchers released a paper in Ecology and Evolution, discussing that hemoglobin protein gene has been found in the microalgae living with the coral that may be able to measure physiological stress, determining that “[hemoglobin] patterns can be affected by a number of factors including hypoxia, organogenesis, pathogen infection and ontogenesis” [2].
This could be potentially useful for conservation efforts and even industries to gauge the stress levels of the coral and their algal partners (and perhaps someday be able to intercept the seemingly doomed corals before bleaching occurs). Professor Hoegh-Guldberg of the ARC Centre of Excellence for Coral Reef Studies (CoECRS), describes the use of hemoglobin as a “potential… biomarker” capable of supplying “a clear readout of stress levels in the corals and their symbiotic algae”.

When first discovered, scientists believed that there was only one species of algal symbiont for all species of corals. That idea has been dispelled with the discovery of multiple groups of zooxanthallae, with a variety of different features and habitat preferences – including higher ocean temperatures thresholds. Dr. Andrew Baker of University of Miami, seen in the video below, and his associates are looking into this variation to find a way to prevent the coral from expelling the zooxanthallae in higher temperatures [3]. In laboratory tests, they have been artificially bleaching coral and then exposing it to ‘Clade D’ – a thermal resistant zooxanthallae variation – in an attempt to swap out the original symbiont for one that could survive in increased temperatures. In theory, this could be utilized in coral reefs that are beginning to experience increased ocean temperatures or to coral larvae that are artificially inserted in restoration areas.

Could you imagine if future conservationist could one day be able to monitor the stress levels of at-risk coral reefs (via the hemoglobin biomarkers mentioned previously) and introduce thermal resistant zooxanthallae in time to save them?

Climate change caused by human interaction is of huge importance to the destruction of coral habitats, but it is not the only cause of the “Anthropocene”. Overfishing of the coral itself and its inhabitants for consumption and decorum haunt the once flourishing reefs. Trawling of the ocean floor wipes out entire reef habitats, as does dynamite and cyanide fishing.

How do we raise concern for the preservation of Earth’s coral reefs?

TED Fellow and socio-ecological artist Colleen Flanigan has teamed up with the Global Coral Reef Alliance (GCRA) to fuse art, technology and conservation together to help raise awareness and promote the salvation of coral and its inhabitants. Since 2004, she has worked with GCRA and Biorock® using her background in design, gardening, and metalworking to “bring visibility to the problem”. Her main emphasis being that people may be inspired once they are able to interact with the beauty of a sculpted “coral refuge”.

Coral Skirt Biorock® sculpture transplanted to
reef in Bali. ©

Biorock® utilizes electrolysis to literally pull minerals necessary to calcify the shell of coral polyps to the metal framework, which once coral is transplanted to the metal frame increases growth rapidly. In her TEDtalk Coral Restoration: Cultivating Mutual Symbiosis, she enters the TEDx stage in Monterey, California in a costume resembling a mix between a jellyfish and a coral reef. Just great (see image below).
Getting ready to go onstage for her TEDx
Talk in Monterey, CA. 
© TED.
This implementation of beauty in the conservation of coral reefs may be the key to unlocking universal compassion and bring about more aggressive efforts to maintain coral reefs, which as mentioned earlier are extremely important for marine biodiversity, protection against erosion, and human recreation.

To learn more about the efforts of Colleen and the GCRA off of the coast of Mexico, visit their website. Want to learn how to get involved? Take a look at the U.S. Department of Commerce's National Oceanic & Atmosphere Administration's website, or opt to volunteer in the Florida Keys with expert divers through the Coral Restoration Foundation to transplant coral buds. Not looking to get that involved? Check out the Nature Conservancy's 10 easy ways to help preserve the reefs.

Peer-Reviewed Articles:

  1. [1] Jones, R., Bower, J., Hoegh-Guldberg, O. & Blackall, L., 2004. Dynamics of a temperature-related coral disease outbreak. Marine Ecology Progress Series 281, 63-77. 
  2. [2] Baker, A., Glynn, P. & Riegl, B., 2008. Climate change and coral reef bleaching: An ecological assessment of long-term impacts, recovery trends and future outlook. Estuar. Coast. Shelf Sci., 1-37. 
  3. [3] Baker, A. 2003. Flexibility and specificity in coral-algal symbiosis: Diversity, ecology, and biogeography of Symbiodinium, The Annual Review of Ecology, Evolution, and Systematics Online, 34, 661-689.

  1. NOAA, “Coral as Medicine”. NOAA Coral Conservation Program:
  2. Walker, R. “Holy Holocene, It’s the Anthropocene”. Huffington Post:
  3. Biello, D. “400 PPM: Carbon Dioxide in the Atmosphere Reaches Prehistoric Levels”. Scientific American Blog:
  4. ARC Centre of Excellence. “‘Blood Test’ for Crook Corals”. ARC Centre of Excellence Coral Reef Studies:
  5. The PEW Charitable Trust. “Helping Corals to Survive Climate Change and Warming Oceans” Research Program Project Details of Marine Fellow Andrew Baker:
  6. TED Fellows Profiles. “Colleen Flanigan”. TED:
  7. NOAA, “Get Involved”. NOAA Coral Conservation Program:
  8. Coral Restoration Foundation, “Get Involved”. Coral Restoration Foundation:
  9. The Nature Conservancy, “10 East Steps to Help Protect Coral Reefs”. The Nature Conservancy:


  1. "Coral Restoration: Cultivating Mutual Symbiosis". Colleen Flanigan TEDx Monterey:
  2. "Heat Resistant Zooxanthellae". Dr. Andrew Baker with Reef Resilience:

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