Skeletons Beneath the Waves

By Eric Cramer

Pocillopora eydouxi bleach

Briny water spills into the tide pools beneath the pier at Cannery Row, filling the crevices in the rocks.

Thirty feet below the waves, I watch a seal as it swims towards me. It flips and twists away from me, but seems magnified as the light bends through the water. I exhale into the regulator and blow bubbles. The seal swims through them, its sleek fur seemingly close enough to touch. The seal surfaces and is washed out in the sunlight. I descend to the ocean floor and study a branch of coral reaching out from a nearby rock. It is bleached white.

Rising global temperatures have led to an increase in sea surface temperatures of about one-and-a-quarter degrees Fahrenheit above the 1971-2000 average.[1] At this temperature, the colorful algae living symbiotically within the cells of coral begin to produce toxic forms of oxygen. This reaction causes the coral to expel the vibrant nutrient-rich algae into the water, leaving its bone-like structure behind. Much like we see the bones in a starving person, we can now see the osteology of this dying coral.

While sea surface temperatures rise, so does ocean acidity. As the ocean absorbs more and more of the 9.7-plus giga-tons of carbon dioxide released each year, a simple chemical reaction occurs.[2] Carbon dioxide and water mix, creating negatively charged bicarbonate and lowering the ocean’s pH. Just like years of drinking acidic sodas will wear away the enamel on teeth, this ocean acidification demolishes the beautiful structures erected by the slow building coral.

The simplicity of the chemistry makes this problem exceptional – we understand how the phenomena works, and we can observe its progress. Just like my magnified view of the seal, the visible deterioration of the coral brings it to the forefront of our scientific understanding. But the vastness of the ocean and the timescale by which it operates makes these ecological changes stick. Once the process is set in motion, it is bewilderingly difficult to stop.

But for now, I will put on my wetsuit – currently powerless to stop the noxious belching of global industry – and dive into the water. I want to observe everything I can see, before it is all gone.


  1. Environmental Protection Agency. (2016, August). Climate Change Indicators: Sea Surface Temperature. Retrieved from
  2. National Oceanic and Atmospheric Administration. (2016, October 5). How does climate change affect coral reefs? Retrieved from

Photo courtesy of pvandyke3, Flickr CC License 2.0