ecology

Every Drop Has a Name

I need you to understand something about a cup of river water, and I need you to not be bored, because what I'm about to tell you might be the most important thing I've written for this newspaper. Last Tuesday, my graduate student Tomoko Arai walked into my office with a sample tube containing approximately 250 milliliters of water from the Ner River, collected at Station 12, about six kilometers upstream from the hydroelectric dam. She set it on my desk and said, "There are 347 species in this