Q. Dear Umbra,

My question pertains to the pH of our Earth’s oceans: Is this pH decreasing, and, if so, what components of the marine environment act as buffering agents? I’m really concerned that the coral sold for aquariums and as a source of calcium for poultry may serve an important purpose in our oceans.

Lucy H.

A. Dearest Lucy,

Back in middle school, my science teacher had a beautiful saltwater aquarium in her classroom. We all loved gazing at the colorful fish darting among the coral — until we started our oceans unit, that is. As she lectured about the importance of coral reefs and the many threats to them, somebody suddenly shouted, “Hey! Then why did you buy coral for the aquarium? Shouldn’t you have left it in the ocean?” Class that day rapidly turned into a student walkout, picketing session, and chants of “Free the Aquarium Seven!” Since then, the health of our coral reefs has been near to my heart.