Out of their shells

If you pour vinegar on to a seashell, you can see it bubble and fizz a little where the vinegar touches the shell. The acid in the vinegar reacts with the shell, slowly eating it away. The oceans are much less acidic than vinegar, of course, but while a tiny change in pH might not have a big affect on larger shelled animals, it stresses smaller organisms and developing individuals. When the ocean is eating the very materials their bodies are made of, thriving and reproducing is far from a certainty for these organisms.

In the ecosystem of the oceans, it’s not just shelled creatures that could be ultimately affected. In some parts of the ocean, minuscule shelled animals make up a huge portion of the available food. If they were to disappear, the disaster could run all the way up the food chain. Animals that eat the shelled organisms would suddenly find themselves with much less food, and then so would the animals that eat them, and so on. The health of the oceans can hinge on its smallest residents, so scientists like Gretchen Hofmann are working to understand just what’s happening to them in our warming, acidifying oceans.

Species like this Antarctic sea-butterfly, vulnerable to changing ocean temperatures as well as increased acidity, may be the first to find themselves without a suitable habitat.
Species like this Antarctic sea-butterfly, vulnerable to changing ocean temperatures as well as increased acidity, may be the first to find themselves without a suitable habitat.
Courtesy Alexander Semenov