Sea Snails: Canaries in the Coal Mine

Sea Snails: Canaries in the Coal Mine

Transparent sea snails known as pteropods – meaning “wing-foot” – are the butterflies of the open ocean. Not only are these tiny, free swimming molluscs beautiful to look at, but they play a pivotal role in the ocean’s food web. They are an important component of the diet of fish-like salmon, herring, and other species that humans rely on for food. But recent research reveals that they may be in jeopardy.

These tiny sea creatures became the spotlight of climate change news when a report from the National Oceanic and Atmospheric Administration announced that the ocean’s changing pH balance was causing their shells to dissolve.

The ocean is naturally alkaline, and has been for millions of years, traditionally at an average pH of 8.2. Today that number has dropped to about 8.1, representing a 25-percent increase in acidity over the past two centuries, and is expected to decline even further. Much of the CO2 output from burning fossil fuels that ends up in the atmosphere is subsequently absorbed by the ocean causing a change in seawater alkalinity. The process of the ocean becoming “less basic” is climate change’s caustic cousin known as ocean acidification.

What is happening to the pteropods is just one of many examples of species being affected by ocean acidification. This is already affecting a wide range of marine life including oysters, plankton,  sea urchins, crabs, coral reefs, and the ecosystems and industries surrounding them. Studies have also shown that acidification can make fish more anxious, foolhardy and even causes them to lose their sense of smell – all key to their survival from predators. The impacts of a disrupted ocean will have huge ramifications on the global economy and our food supply.

The sea butterfly is like the canary in the coal mine. It’s plight should be a wake up for all of us to become more mindful of our effects on the planet and attempt to lower our impact. Our ocean-reliant food web is in danger of being dissolved.

The ability of the ocean to remove CO2 from the atmosphere reduces the rate of climate disruption. Thus, perhaps the most frightening question to ask regarding ocean acidification is when will the ocean lose the ability to absorb more C02? Seawater has a maximum absorption level, and at a certain point the ocean will no longer be a buffer system and will stop absorbing the CO2 that we are emitting on a daily basis. What will happen to our atmosphere when this CO2 has no where else to go?

Online Ocean Symposium recently brought together experts to discuss the hows, whys and whats of ocean acidification. The discussion was live-broadcast through Google hangouts. The conversation also included solution-oriented discussion through the work of the Wendy Schmidt Ocean Health XPRIZE. I welcome you to watch and learn more about this issue.

Sea snail image via

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