The Stark Unpainted Canvas of Coral Bleaching

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When you think about the changing climate and the impact this has on the marine environment, your first thought might be melting polar ice caps. Yet corals are among the most sensitive ecosystems and may be the most affected by climate change in the near future. In Hawaii, with water temperatures 3 to 4 degrees higher than average, we are experiencing the highest bleaching threat level for coral, the impacts of which could be devastating.

I grew up on the island of Hawaii, living near the coast for 18 years before moving to the “mainland” for my higher education. I discovered my passion for the ocean early on in life as I spent so much of my time in the water. But when many of my friends were out surfing, I could be found snorkeling the endless coral reefs, checking out the different fish and marine wildlife I encountered. During this time I never experienced a bleaching event. But you know one when you see one.

Coral bleaching occurring in the leeward coast, Oahu, Hawaii, October 10, 2015. © Alexa Vitek / WWFCoral bleaching occurring in the leeward coast, Oahu, Hawaii, October 10, 2015. © Alexa Vitek / WWF

As when you swim over the reef, all you can see is a field of white coral. It is a stark white, like an unpainted canvas instead of the usual greens, reds and yellows you might expect. The first time I saw coral bleached was in Indonesia in 2010. What I hadn’t expected was how much the bleaching extends beyond just corals – even the anemones are bleached. Over time, the corals die off, become covered in algae and eventually become just skeletal fragments, no longer offering a healthy ocean habitat for the species that rely on them for food and protection.

But this picture of our ocean can be changed, and we are learning to adapt. In September 2015, I co-authored a paper along with several other scientists on how to prioritize management of the ocean for resilience to climate change. Marine planners can determine which reefs are more vulnerable and prioritize those intact reefs that might be resilient to change. This is done by looking across all the threats, from fishing and pollution, to development and climate change, while assessing the types of fish and communities of coral. We need to manage for this kind of change now, because we can’t immediately halt the warming and acidification already happening in our ocean.

© Alexa Vitek / WWF© Alexa Vitek / WWF

As El Niño develops, we are starting to see high sustained temperatures across the Pacific, and marine scientists are keeping our eyes on the Coral Triangle. This region has expansive, diverse coral reefs with many coastal communities dependent on these reefs for their food and livelihoods. For them, coral bleaching isn’t just the destruction of nature’s art – it’s a real threat to people’s health and well-being.

As world leaders prepare to meet in Paris next month to work on a global climate deal, I can only hope they act with real urgency. Coral reefs, and the marine species and people who depend on them, can’t wait.

Dr. Gabriella Ahmadia is a marine conservation scientist with WWF-US.

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